ABSTRACTBackgroundSystemic inflammatory diseases (SIDs) have been reported in patients with sickle cell disease (SCD), but clinical data in children are scarce.ObjectivesTo identify clinical and laboratory features at diagnosis of SID in children with SCD and to describe their evolution.MethodsData from children with SCD and SIDs were retrospectively collected in a French multicenter study from 1991 to 2018. Information included clinical characteristics, inflammatory markers, autoantibodies patterns, treatments, and complications. Inflammatory marker levels were compared at SID diagnosis and at the last follow‐up. Statistical analyses were performed using Cran R software.ResultsAmong a cohort of 3800 children with SCD, 43 SIDs were identified in 35 study participants: autoimmune liver disease (AILD, n = 13), inflammatory bowel disease (IBD, n = 7), juvenile idiopathic arthritis (JIA, n = 6), systemic lupus erythematosus (n = 4), autoimmune hemolytic anemia (n = 3), Sjögren syndrome (n = 1), histiocytic necrotizing lymphadenitis (n = 2), vasculitis (n = 2), myasthenia gravis (n = 1), sarcoidosis (n = 1), idiopathic inflammatory granulomatous uveitis (n = 1), mixed connective tissue disease (n = 2). Prevalence of SID was 0.9% in our cohort of children with SCD. The median time between initial symptoms and SID diagnosis was 10 (3–20) months, notably longer in children with JIA, IBD, and Sjögren syndrome. Sixteen patients (46%) exhibited hypergammaglobulinemia (>20 g/L) at diagnosis. No significant differences were observed for other inflammatory parameters. Twenty‐one children (60%) received systemic steroids and 13 (37%) biological therapies. Three patients (9%) underwent hematopoietic stem cell transplantation. Nine patients (26%) had severe infections; one died.ConclusionDelayed diagnosis was frequent due to overlapping clinical presentations between SCD and SID. Clinicians must be aware of warning signs associated with elevated inflammatory markers, hypergammaglobulinemia, or specific antibodies. Therapeutic strategies remain challenging.

Autoimmune and inflammatory diseases (AIIDs) encompass a spectrum of systemic or organ-specific conditions, wherein the immune system is compromised due to a loss of self-tolerance. AIIDs have been reported in both adults and children with sickle cell disease (SCD), but clinical data are still scarce, particularly in children. To identify clinical and paraclinical patterns at diagnosis of AIIDs in children with SCD and to describe their evolution, we performed an observational study among a cohort of 3,800 children with SCD, in a French multicenter study from 1991 to 2018. The inclusion criteria were i) children with SCD, ii) one or more concomitant AIIDs confirmed according to the diagnostic criteria published by the American College of Rheumatology and the European League Against Rheumatism, iii) AIID diagnosis before the age of 18 years-old. Children with isolated positive autoantibodies or autoimmune-like manifestations without a definitive diagnosis were excluded. Data from SCD children with AIIDs were retrospectively collected and included clinical characteristics, inflammatory markers (at diagnosis and after treatment), auto-antibodies patterns, evolution during follow-up (treatment, remission and occurrence of complications). Thirty-five children with SCD reported 44 AIIDs (0.9%, 95%CI [0.6-1.3]). Sex ratio was 0.84 and the median age was 10 [IQR 7-13] years-old at AIID diagnosis. The median length of follow-up was 13.5 [IQR 10-19] years. Thirty patients (86%, 95%CI [70-95]) had the S/S genotype, four (11%) the S/C genotype, and one (3%) the S/beta0 thalassemic genotype. AIIDs diagnosed were: auto-immune liver disease (AILD, n=13) including autoimmune hepatitis (AIH, n=8) and autoimmune sclerosing cholangitis (AISC, n=8), inflammatory bowel disease (IBD, n=7), juvenile idiopathic arthritis (JIA, n=6), systemic lupus erythematosus (SLE, n=5), autoimmune hemolytic anemia (AIHA, n=3), Sjögren syndrome (n=2), histiocytic necrotizing lymphadenitis (n=2), vasculitis (n=2), myasthenia gravis (MG, n=2), sarcoidosis (n=2), inflammatory uveitis (n=1), sclerodermia/juvenile dermatomyositis (JDM, n=1). Eight patients (23%, 95%CI[10-40]) had two or more concomitant AIIDs, including mixed connective tissue diseases (n=2, with SLE + Sjögren's syndrome, and scleroderma + JDM), SLE-associated MG (n=1), AISC with IBD (n=3), AISC with sarcoidosis (n=1), and concomitant AISC with AIH, IBD, and AIHA (n=1). The mean time between the first symptoms and AIID diagnosis was 15.5 (± 29) months, with longer durations for JIA, IBD and Sjögren's syndrome. Two patients (6%, 95%CI [0.7-19]) required intensive care at AIID diagnosis: one patient with MG for extracorporeal membrane oxygenation, and one with acute liver failure. Children diagnosed with AILD had highest hypergammaglobulinemia level at diagnosis (31 ± 8.6 g/L), which significantly decreased at last follow-up (18 ± 4.9 g/L; p=0.003). At AIID diagnosis, antinuclear antibody (ANA) titers were weakly positive (1:160) in five patients (14%, 95%CI [4.8-3]), moderately positive (1:320 to 1:800) in nine patients (26%, 95%CI[12-43]), and strongly positive (≥1:1280) in six patients (17%, 95%CI [7-34]). Of the 21 children (60%) treated with systemic steroids, 14 (67%) experienced vaso-occlusive crisis. Thirteen patients (37%, 95%CI [21-55]) received biological therapy, including anti-interleukin IL-1 (n=2, 6%), anti-IL-6 (n=2, 6%), anti-CD20 (n=6, 17%), anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4; n=4, 11%), and anti-tumor necrosis factor (TNF)α (n=11, 31%). A complete remission of AIID was observed in 26% (95%CI [12-43], n=9/35) of the patients.Nine patients (26%, 95%CI [12-43]) had severe infections. Three children (9%) underwent hematopoietic stem cell transplantation, one died of steroid-resistant multipolar graft-versus-host reaction. Prevalence of AIID was 0.9% in our cohort of 3800 children with SCD, which is one of the largest pediatric series to date, among this specific population. Delayed diagnosis was frequent due to intricated clinical patterns between AIID and SCD. Clinicians must be aware of warning signs associated with elevated inflammatory markers, hypergammaglobulinemia or specific antibodies. Therapeutic strategies remain challenging for those vulnerable children.

The impact of hydroxyurea (HU) on the ovarian reserve of female patients with sickle cell disease (SCD) remains poorly elucidated. Only direct histological analysis of ovarian follicle density can effectively evaluate HU's effect on ovarian reserve. By analyzing digitized slides of ovarian tissue from girls and young women with SCD who underwent ovarian tissue cryopreservation (OTC) before hematological stem cell transplantation (HSCT), we meticulously counted follicles and categorized them based on their growth stage. We then calculated the densities of different follicle types and assessed their correlation with patient characteristics, clinical manifestations, and treatments extracted from medical records. Seventy-six SCD patients participated in the study, with a median age at OTC of 10.2 years (interquartile range [IQR] 7.5, 14.6), and 50 (65.8%) were prepubertal. Of these, 35 patients (46.1%) had received HU, with a median daily dosage of 23.0 mg/kg (IQR 20.0, 25.0) and median exposure time of 44 months (IQR 24.0, 54.0). Primordial follicle density was comparable between the HU and non-HU groups (5.8 follicles/mm2 [IQR 1.0, 13.3] versus 4.2 follicles/mm2 [IQR 1.1, 14.4], respectively; P = .95). However, in the HU group, after adjusting for age, the density of growing follicles was marginally lower compared to the non-HU group (P = .09). Notably, other parameters such as vaso-occlusive crisis did not affect follicular density. In conclusion, exposure to hydroxyurea did not demonstrate a reduction in ovarian reserve in girls/women with SCD. Therefore, fertility preservation measures before initiating HU treatment do not seem necessary.

To describe the experience of performing ovarian tissue cryopreservation (OTC) before hematopoietic stem cell transplantation (HSCT), among girls/women with severe sickle cell disease (SCD)(SS or S/β0-thalassemia) who are, besides the usual surgical risk, at risk of SCD-related complications during the fertility preservation procedure for improving their counseling and management. This retrospective study included 75 patients (girls/women) with SCD who have had OTC before myeloablative conditioning regimen (MAC) for HSCT. Characteristics of patients and data on OTC, ovarian status follow-up, and results of ovarian tissue transplantation (OTT) were collected in medical records. At OTC, the median (IQR 25–75; range) age of the patients was 9.6 (6.9–14.1; 3.6–28.3) years, 56/75 were prepubertal, and no SCD or surgery-related complications occurred. The median follow-up post-HSCT was > 9 years. At the last follow-up, among prepubertal patients at HSCT, 26/56 were ≥ 15 years old and presented with a premature ovarian insufficiency (POI), except 2, including the patient who had received an OTT to induce puberty. Eight were 13–15 years old and presented for POI. The remaining 22 patients were under 13. Among the 19 patients who were menarche at HSCT, 2 died 6 months post-HSCT and we do not have ovarian function follow-up for the other 2 patients. All the remaining patients (n = 15) had POI. Five patients had OTT. All had a return of ovarian function. One patient gave birth to a healthy baby. OTC is a safe fertility preservation technique and could be offered before MAC independent of the patient’s age.

DREPAGREFFE-1 (NCT01340404), was the first prospective trial comparing allogeneic stem cell transplantation (alloSCT) to standard-of-care (SoC) in children with sickle cell anemia (SCA). This French multicenter trial was defined by the random-availability of a matched-sibling donor (MSD). Inclusion criteria were SS/Sb0 children (5-15yr) placed on long-term chronic-transfusion (CT) for a history of abnormal cerebral arterial velocities (TAMMV≥200 cm/sec), with at least one non-SCA sibling, and parents accepting HLA-typing and alloSCT if an MSD was available.Sixty-seven children (35F/32M), including 7 with stroke-history, were enrolled (Dec-2010/June-2013). Children with MSD (n=32) were transplanted, while those without (n=35) were maintained on CT for at least one year and then switched to hydroxyurea (HU) if normalized TAMMVs and no stenosis. Results at 1 and 3 years were reported (Bernaudin et al JAMA. 2019;321(3); Verlhac et al Br J Haematol. 2021;193(1)). As a reminder, comparing alloSCT vs. SoC at 1 yr, the highest TAMMVs (primary outcome) were significantly lower after alloSCT than under SoC (difference -40.8 cm/s; [95%CI:-62.9;-18.6]; P<.001). At 3 years, the highest TAMMVs were lower, the proportion of patients with normalized-TAMMVs was higher, the stenosis score in stroke-free patients was lower, and the quality of life (QoL) was better for physical and school functioning. Nevertheless, no significant difference in ischemic lesions and cognitive performance was observed.DREPAGREFFE-2 trial (NCT 05053932), supported by ABM and Pfizer, aimed to reevaluate at 10yr the 67 SCA-children (Sept-2022/Aug-2024) to test whether the differences in cognitive performance and ischemic lesions had changed significantly. Events and treatment changes since Year 3 were routinely recorded. Clinical evaluation, routine biological check-up, Intracranial and cervical-color Doppler-ultrasound, cerebral MRI/MRA/neck-MRA were performed. Non-opposition consent was required for cognitive testing (WISC-V and WAIS-IV), biological research, and QoL (PedsQLTM) assessment. Death and stroke did not occur in either arm.In the alloSCT arm (n=32), follow-up ended at 7.0 and 7.9 years for 2 children with full donor-chimerism and no chGvHD, due to return to Africa and UK. At 10yr, median (range) donor-chimerism was 92.5% (19%-100%) and no chGvHD was observed.In the SoC arm (n=35), 23 patients with normalized velocities and no stenosis under CT were switched to HU. At 10yr, 17 are still on HU, 15 are on CT, and 3 had related haploIdentical-SCT at 6.7, 7.2 and 9.3yr post-enrollment. They are well, one having only mild chGvHD. Two patients still on CT for stroke-history did not give consent for research analyses.Including the 3 haplo-SCT with the alloSCT-arm for analysis at 10yr, Hb and HbA% were higher while HbS%, Retic., WBC, neutro, bilirubin, LDH, and ferritin were lower in the alloSCT vs. SoC arm (P<.001 for all).Available mean (SD) QoL at 10yr in alloSCT (n=25) vs. SoC (n=28) was not different for emotional but higher for physical (84.0 (16.3) vs 76.4 (11.2); P=.013), school (72.6 (17.2) vs 61.4 (14.7);P=.016) and even social functioning (93.8 (10.7) vs. 86.4 (12.9); P=.003).MRI/MRA and cognitive performance data were only analyzed in stroke-free patients. At enrollment (T0), silent cerebral infarcts (SCI) were present in 6/31 in the SoC-arm and 12/28 in the alloSCT arm. At 10yr, 5 additional patients had developed SCI in the SoC arm, but none did in the alloSCT, while SCI were either no more visible or <3mm in 1 (SoC) and 4 patients (alloSCT) (P=.010). Comparing alloSCT (n=24) to SoC (n=21), cognitive testing showed no difference in verbal comprehension and perceptual reasoning index, while the mean (SD) working memory index (WMI) was higher (89.6 (11.8) vs 80.5 (10.8); P=.021) with a digit span of 8.4 (1.9) vs. 6.7 (1.8)(P=.005), the processing speed index (PSI) was higher (96.5 (21.9) vs. 83.7 (14.4);P=.035) with a symbol search of 9.3 (2.0) vs. 7.3 (2.9)(P=.021), respectively. Compared to T0, mean (SD) WMI and PSI at 10yr improved, although not significantly, in transplanted patients [+5.8 (15.6) vs. +9.0 (25.4)] but not in the SoC arm [-2.0 (15.7) and +0.6 (19.7)].Thus, this first prospective comparative trial demonstrates that differences between alloSCT and SoC changed significantly at 10yr with alloSCT providing better primary prevention of SCI, social QoL, working memory and processing speed

Newborn screening with comprehensive care has decreased early mortality and prevented overt stroke in many children with sickle cell disease (SCD).1, 2 Few studies have addressed the overall disease burden, and transfusion needs during childhood have yet to be assessed. Over the last three decades, the pediatric department of the Créteil Intercommunal University Hospital (CHIC), a referral center for SCD, has prospectively evaluated vaso-occlusive crisis (VOC), acute chest syndrome (ACS), hematological and major organ complications in a newborn cohort of children with SCD. According to national guidelines, hydroxyurea (HU) was administered to children after the recurrence of VOC or ACS, and transfusion program (TP) was implemented for stroke prevention. Specifically at our center, hematopoietic stem cell transplantation (HSCT) was also offered to patients with cerebral vasculopathy or frequent VOC/ACS with a human leukocyte antigen-identical sibling. We used the administration of disease-modifying therapies (DMT) including HU, TP, and HSCT, as a surrogate for disease severity. Our main objective was, therefore, to evaluate morbidity in children with SCD over a period beginning with the introduction of newborn screening (1986) and ending just before the introduction of preventive intensification with HU (2015). Kaplan–Meier (KM) survival estimates and the 95% confidence interval (95% CI) were calculated for all SCD-related complications, and use of DMT. Incidence rates were calculated as the number of events divided by total person-years (PY) at risk. PY after HSCT are excluded. This study was approved by our institutional ethics committee (no. 2021-07-02). This newborn inception cohort includes four SCD genotypes: SS and Sβ0 thalassemia (n = 289), sickle-hemoglobin C disease (SC n = 65), sickle β+ thalassemia (Sβ+ n = 32), and SDPunjab (SD n = 3), and it provides 4588 PY of observation. We considered individuals with the HbSS, HbSβ0, and HbSD genotypes as a single group (the severe sickle genotype group) because of the known clinical similarity of diseases and the small number of HbSD/Sβ0 subgroups. The median duration of follow-up (FU) was 13.2 (range: 1.2–23.6) years and 229 patients were still in FU at our center at the end of June 2021. Demographic and baseline biological characteristics, together with FU data are summarized in Table S1. Ten of the 389 patients died during FU, at a median age of 10.8 years (range: 1–20 years). Nine of these patients died from SCD-related causes, and all but one had HbSS disease. One death at 13 years was observed in a woman with HbSβ+ disease, due to massive pulmonary embolism right after a long air flight. The probability of survival at 5 years was 98.2% (95% CI: 96.6%–99.3%) for the total study population, with deaths observed only in the severe genotype group (97.6% [95% CI: 95.5%–99.0%]). Consistent with other SCD cohorts, at the age of 15 years, overall survival was 97.4% (95% CI: 95.4%–98.8%) for the total population, and 97.2% (95% CI: 95.0%–98.8%), 100% (95% CI: 100%–100%), and 90.9% (95% CI: 68.0%–100%) for the HbSS/SD/Sβ0, HbSC, and HbSβ+ genotype groups, respectively. Probabilities of acute SCD-related events (VOC, ACS, acute splenic sequestration [ASS], acute exacerbation of anemia [AEA], first transfusion, cholelithiasis, and DMT initiation) are shown in Figure 1A,B. The cumulative risk of major organ complications: elevated tricuspid regurgitation velocity (TRV) (above 2.5 m/s); sickle nephropathy (microalbuminuria defined by an albumin-to-creatinine ratio ≥30 mg/g); and sickle retinopathy (proliferative or not) are shown in Figure 1C. The long-term risks of cholecystectomy and splenectomy are shown in Figure S1. As reported in other neonatal cohorts, the earliest and most frequent events were VOC and ACS, the risks of both being significantly higher in HbSS/SD/Sβ° patients (with 50% of children experiencing at least one VOC by the age of 5 years and one ACS by the age of 10 years).1, 2 In our cohort, the 5-year probability of these events was slightly higher than the overall probability reported in the national retrospective study, undoubtedly reflecting the prospective nature of our study.1 The probabilities of these events did not differ significantly between the HbSC and HbSβ+ genotypes. Interestingly, the long FU for this cohort made it possible to detect less common events resulting from cumulative organ damage: by 15 years of age, the overall probability of a high TRV was 20.5% (95% CI: 15.6%–25.9%) for all genotypes and 23.7% (95% CI: 17.9–30.1) in the severe genotype group. As in many other studies, we defined a high TRV as a TRV of ≥2.5 m/s, as this threshold is associated with mortality in adults with SCD. TRV ≥2.7 m/s has more recently been shown to be a more appropriate definition of high TRV, and significantly associated with death in children, adolescents, and young adults.3 The risk of microalbuminuria was lower in our cohort than in other pediatric studies,4 reaching only 7.9 % (95% CI: 4.8%–11.6%) at 15 years, with no difference between the severe (8.7% [95% CI: 5.1%–13.2%]) and HbSC (6.6% [95% CI: 1.2–16.2]) genotypes. Whereas other published studies were cross-sectional, in this study, urine was sampled regularly from the age of 5 years, and at least two positive urine samples were required for diagnosis. Furthermore, we recently systematically tested urine samples collected in the recumbent position, to exclude orthostatic proteinuria. Alternatively, the widespread early use of DMT in the severe sickle genotype group may have decreased infarction and hemolysis-related glomerular damage, in turn influencing the development of sickle cell nephropathy. This study is the largest to date evaluating the incidence of retinopathy during childhood. Our findings confirm that retinopathy affects patients with the HbSC genotype at a much higher frequency, confirming the need for earlier screening in these children. Proliferative retinopathy developed as early as 7 years of age in one girl with HbSC disease, necessitating laser photocoagulation. DMT, reflecting severe disease, was introduced for 247 of the 292 children with HbSS/SD/Sβ° genotypes, at a median age of 4.1 years (0.5–17.8 years). By the age of 15 years, the probability of DMT initiation was 87.7% (95% CI: 83.3%–91.5%). Despite the widespread use of HU in the severe genotype group (probability of 64% [95% CI: 58.2%–69.8%] by the age of 10 years), substantial long-term morbidity due to acute complications of SCD was observed, with overall rates of 63.8/100 PY for VOC, 16.1/100 PY for ACS, 10.7/100 PY for AEA, and 6.9/100 PY for ASS (Figure 1D). These rates were unexpectedly similar to those reported in other neonatal cohorts taking into account only events occurring before the advent of DMT.2 First, our study did not address adherence to treatment, and HU dose was not recorded in our database. Moreover, HU was rarely increased to the maximal tolerated dose (MTD), as reflected by the moderate myelosuppression observed in another CHIC cohort (mean absolute neutrophil count 3.9 ± 1.9 x 109/L on HU at last check-up). This study provides new information about the overall transfusion requirements in SCD (Figure 1E): as expected, the transfusion burden is particularly heavy in the severe genotype group, with an incidence of transfusion episodes of 299/100 PY. Most transfusion episodes were delivered during chronic TP (245/100 PY). Primary stroke prevention accounted for most of the TP indications (33.5%). For children living in high-income settings, the 2020 American Society of Hematology guidelines suggest that HU treatment at the MTD can be considered to substitute for TP, in children with no severe vasculopathy, and after at least 1 year of regular blood transfusions. Certainly, this approach will decrease overall transfusion requirements. VOC and ACS recurrence despite HU accounted for 19.5% of the indications for TP initiation in our cohort. We believe that the recurrence of vaso-occlusive events driven by a sub-optimal HU dosing regimen could lead to patient discouragement, and explain in part over time nonadherence to HU. Considering trials demonstrating that dose escalation was safe and provided considerably greater clinical and biological benefits than 20 mg/kg per day dosing, we now consider HU earlier initiation with escalation to MTD in all young patients with HbSS/Sβ0 thalassemia.5 Finally, another frequent indication for the TP initiation in our study was prevention of ASS recurrence (17.8%). Interestingly, some of the strongest predictors of splenic function preservation in children treated with HU were a younger age at the initiation, a shorter time to reach MTD, and a greater increase of fetal hemoglobin from baseline.6 It is however unclear, whether early initiation of HU with rapid escalation to MTD might decrease the risk of ASS and the need for TP for ASS recurrence prevention. In conclusion, we report here the longest prospective neonatal cohort study to date addressing acute vaso-occlusive, hematological, and extracerebral major organ complications, and providing new data about transfusion requirements in SCD children. In the absence of preventive intensification with HU, SCD continues to cause substantial morbidity and the use of blood resources remains considerable. Several studies have reported beneficial effects of HU treatment, reducing recurrent episodes of pain, dactylitis, ACS, hospitalization, and transfusions. We believe that its preventive effects following early introduction and dosage escalation to the MTD should alter the course of the disease, and that its substitution for chronic transfusions to prevent primary stroke should decrease overall blood requirements. Involving individuals with SCD and their families in medical decision-making will be critical, to increase adherence to treatment. Recognition of the severity of the disease also provides a rationale for the early performance of genoidentical HSCT. Alizée Soulié and Corinne Pondarré cared for patients, designed the study, collected and interpreted the data, wrote the article, and took final responsibility for the decision to submit for publication. Ekaterina Belozertseva collected data. Eric Guémas carried out the statistical analysis. Florent Neumann collected and interpreted some data. Serge Pissard analyzed genetic markers. Bassem Khazem was involved in the collection of biological and transfusion data. Annie Kamdem, Cécile Arnaud followed patients, collected, and interpreted the data. Isabelle Hau, Fouad Madhi, Céline Delestrain, Mickaël Shum, Adèle Carlier-Gonod, Aline Malterre, Harry Lezeau, and Ralph Epaud cared for the patients. All the authors reviewed the paper and approved the final manuscript. We thank Dr. F. Bernaudin for the design of the database, for having collected data, and having provided care for study patients. We thank her for her important scientific contribution to the field of sickle cell disease. We thank all the patients and their families for participating in this study, and all the nurses from the various inpatient and outpatient units for their dedication. We thank Maxime Brussieux for collecting data. We thank Julie Sappa, from Alex Edelman & Associates, for English editing assistance. C.P. reports honoraria for Novartis and expert consultancy for Addmedica, Global Blood Therapeutics, and Pfizer. E.G. reports expert consultancy for Addmedica. All other authors declare no conflict of interest. All data generated or analyzed during this study are included in this published article. Figure S1. Kaplan–Meier curves indicating times to cholecystectomy and splenectomy. The green or solid line corresponds to children with severe sickle genotypes, the red or long dashed line to children with the HbSC sickle genotype, and the blue or short dashed line to children with the HbSβ+ sickle genotype. The numbers indicate the probability of event and the 95% confidence interval (in square brackets) at 15 years. Kaplan–Meier event-free survival estimates and 95% confidence intervals were compared between the three sickle genotype groups in log-rank tests. * indicates a significant difference (p < .05) between the severe and HbSC or HbSβ+ genotypes. ** indicate a significant difference (p < .001) between the severe and HbSC or HbSβ+ genotypes. Table S1. Follow-up data, demographic, and baseline biological characteristics for the neonatal sickle cell disease cohort. Baseline blood parameters were recorded outside of the context of transfusion or painful episodes and before the introduction of any disease-modifying therapy. The severe genotype group comprises the HbSS (n = 280), HbSβ0 thalassemia (n = 9), and HbSDpunjab (n = 3) sickle genotypes. G6PD, glucose-6-phosphate dehydrogenase. α-thalassemia refers to deletion of one or two α-chain genes. β Haplotypes: BAN, Bantou; BEN, Benin; SEN, Senegal; "Others" indicates all other combinations. The data shown are medians with (range) or mean ± SD. Groups were compared in Student's t-tests and Fisher's exact tests for quantitative and qualitative variables, respectively. * indicates a significant difference (p < .05) between the severe and HbSC or HbSβ+ genotypes. ** indicate a significant difference (p < .001) between the severe and HbSC or HbSβ+ genotypes. ¤ indicates a significant difference (p < .05) between the HbSC and HbSβ+ genotypes. Data S1. Methods including patient follow-up, definition of events, statistical analysis, and ethical considerations can be found online in the Supporting Information section at the end of this article. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative option for sickle cell disease (SCD) in children. This treatment is reserved for severe forms of SCD that progress despite intensive treatment with transfusion therapy or a hydroxyurea program and require an HLA-compatible family member. Although HSCT has substantially improved survival and reduced risk of complications, it can lead to acute or chronic pulmonary complications, the most common being bronchiolitis obliterans syndrome (BOS) corresponding to a manifestation of chronic graft-versus-host disease (GVHD). After allogeneic HSCT for hematological malignancies, pulmonary complications and impaired pulmonary function are common and result in significant morbidity and mortality.1 Only a few studies have focused on the lung function of SCD patients after allogenic HSCT; they suggest a stability of lung function as compared with patients undergoing HSCT for hematological malignancies. Nevertheless, the small size of the cohorts studied and the lack of data on pre- and posttransplant pulmonary function tests (PFTs) do not allow for an accurate assessment of the pulmonary risks of this treatment in this indication. In the present study, we retrospectively analyzed the respiratory function of children and adolescents with SCD who underwent geno-identical allogenic HSCT between May 1990 and June 2016 and were prospectively included in the large cohort of the reference center of Creteil, France. Children were eligible if they had at least one lung function assessment after HSCT and were followed clinically for at least 4 years. Evolution of lung function was assessed in a subgroup of patients who had pre- and posttransplant PFTs by comparing the PFT results performed just before allogenic HSCT with the most recent ones during follow-up. Plethysmography and spirometry were performed and analyzed according to the European Respiratory Society and American Thoracic Society guidelines.2 Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) (FEV1/FVC ratio), and static volumes (vital capacity [VC] and total lung capacity [TLC]) were calculated according to the reference equations proposed by the Global Lung Initiative to account for ethnicity in addition to age, sex and height (http://gligastransfer.org.au/calcs/spiro.html).3 Abnormal lung function was defined as three types of ventilatory defect: obstructive ventilatory defect (OVD) defined by a reduction in FEV1/FVC z-score to less than the lower limit of normal (LLN); restrictive ventilatory defect (RVD) defined by TLC less than LLN confirmed by FVC also below LLN, with normal FEV1/FVC ratio; and mixed ventilatory defect. If no TLC results were available, FVC < LLN with normal FEV1/FVC ratio was considered a restrictive pattern. Severity of RVD was defined in three categories based on z-score: mild (−1.65 to −2.5), moderate (2.51 to −4.0), and severe (≥ −4). The diffusing capacity for carbon monoxide (DLCO), measured with the single-breath technique, was corrected by hemoglobin (DLCOc) and considered pathological when <80%. All parents provided informed consent for data to be used for research. Use of the database was approved by the Centre Hospitalier Intercommunal de Créteil Institutional Review Board and the French National Data Protection Commission (CNIL, no. 2069568). The study was approved by our institutional ethics committee (no. 2021-06-01). Between May 1990 and June 2016, 135 patients with SCD underwent geno-identical allograft: 108 had lung function assessments during posttransplantation follow-up and 44 also had pre-allograft PFTs (Figure 1A). The characteristics of the included patients are summarized in Table S1. All patients underwent transplantation at a median age of 8 years (interquartile range 6–12; range 2–20 years). The stem cell source was only umbilical-cord blood or bone marrow. All patients underwent a pretransplantation transfusion program and most (105 of 108) received the same myeloablative conditioning with busulfan and cyclophosphamide chemotherapy combined with rabbit anti-thymocyte globulin, which is routinely used to prevent GVHD and rejection. In the posttransplantation period, the main immunosuppressive treatment was cyclosporine, with or without methotrexate, for a mean (SD) of 10.1 (4.6) months. For 13 patients, cyclosporine was stopped because of neurological or renal toxicity and switched to mycophenolate mofetil. Of the 19 (18%) patients in whom acute (n = 15) or chronic (n = 4) GVHD developed, only one had a pulmonary location, which was associated with a skin location and none had BOS or graft rejection. Lung function was assessed in 108 patients after transplantation as was the lung function progression of 44 individuals who had also PFTs before transplantation. Two of the youngest children were unable to perform spirometry and had airway resistance measurement before transplantation. However, their pretransplant airway resistance and lung function were normal after HSCT. The characteristics of this subgroup (n = 44) were comparable to those with only post-PFTs (n = 64), except for age at transplantation and GVHD prevention treatment (Table S1). In the whole population (n = 108), 74 (70%) patients had normal posttransplant respiratory function at a median of 6 years after transplantation (Figure 1B). The mean (SD) (expressed in z-score for volumes and in percentage for DLCO ± SEM) respiratory function parameters post-allograft were within the normal range (FEV1 = −0.90 [0.78], FEV1/FVC = 0.28 [0.91], TLC = −1.57 [0.68], DLCOc = 96 [14]). In the subgroup with pretransplant PFTs, the comparison of lung function for each patient at baseline and after allogenic HSCT is shown in Figure 1C–E. The median time between the HCST and PFTs posttransplantation was 5 years (interquartile range 3–7). We found no significant difference in the individual comparison of forced lung volumes before and after allogenic HSCT, as illustrated by superimposing volume distribution curves before and after transplantation. However, we observed a significant and isolated decline in TLC in 26 patients for whom TLC measurement was available before and after HSCT (p = .01). In contrast, 55% of patients showed significantly improved DLCOc (p = .04), with an increase of at least 10% after HSCT. Before HSCT, 83% (n = 34) of the subgroup of patients with pre- and posttransplant PFTs had normal lung function, 5 (12%) had RVD, and 2 (5%) had OVD without respiratory symptoms (Figure 1B). Overall, 57% of patients with abnormal lung function had a history of acute chest syndrome and one patient with OVD was receiving inhaled corticosteroids for clinically well-controlled allergic asthma. Initially, DLCOc decreased in 11 (25%) patients and was most often isolated (n = 10, 90%). Regardless of lung function at baseline, most patients remained stable after transplantation and two patients showed normalized lung function (Figure 1B). RVD developed in one quarter of patients and OVD in only three patients (9%), without clinical symptoms suggesting BOS. After transplantation, the prevalence of RVD and OVD in the whole cohort was similar to that in the subgroup and was 23% and 7% of the whole population versus 27% and 9% of the subgroup. To our knowledge, this is the largest cohort with a long follow-up describing the evolution of lung function after transplantation in patients with SCD. Like previous studies, we showed prolonged stability of lung function in most patients who underwent HSCT and very few pulmonary complications, with only one case of acute pulmonary GVHD.4 In our cohort, the most frequent ventilatory defect in the posttransplant period was RVD, with an estimated prevalence of 24%. This prevalence probably varies with age and has been reported from 20% to 30% in similar studies.5 Although we may have missed short-lived abnormalities in the first 1–2 years post-HSCT, we did not find a significant impact of HSCT on lung function and did not observe bronchiolitis obliterans, the dreaded complication after HSCT. However, more than one-quarter of patients exhibited a decrease in lung volumes, particularly TLC and FVC, and restrictive syndrome developed after transplantation, as previously described.5 The type of transplantation and conditioning regimens may play a role in the development of ventilatory defect, but they are mainly associated with a decrease in FVC and FEV1 but not TLC. Furthermore, children with SCD experience a progressive decrease in lung volume with age, starting in childhood and most often resulting in an RVD.6 This situation may explain a decline in lung function in some patients independent of transplantation, which suggests that transplantation does not completely modify the natural course of SCD. However, further studies are needed to evaluate the rate of decline in lung volume per year before and after transplantation to more accurately assess the impact of transplantation on lung function. As in previous studies, comparison of mean DLCOc before and after allogeneic HSCT showed a significant improvement, with a gain of at least 10%. Although the mechanism remains unclear, the observation may result from an improvement in gas exchange across the alveolar capillary membrane. Our study has strengths but also limitations: a substantial number of patients did not benefit from pretransplantation PFTs owing to their young age and we did not have a predefined time course for PFT. Although ethnicity was taken into account for spirometry with the Global Lung Initiative equations,3 the ethnic origin indicated was African American, which did not necessarily correspond to SCD patients of African origin living in Europe or patients from the Caribbean. To summarize, lung function in SCD children undergoing allograft HSCT remained stable after transplantation, without significant pulmonary complications. However, larger prospective studies are needed to confirm these encouraging results in patients with SCD undergoing HSCT. MG performed the statistical analysis and wrote the original draft of the manuscript. CD conceived and designed the study, wrote and reviewed the manuscript, and verified all data. RE designed the study and wrote and reviewed the manuscript. CP, CA, AK, FB, and BM collected the data, participated in the analysis, and reviewed the manuscript. CD is the study guarantor who attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted. We are grateful to Melissa Masson and Naomie Salaün-Penquer (KADUCEO®) for their assistance in the statistical analysis. We are thankful to Laura Smales for English editing assistance. FB reports expert consultancy for BlueBirdBio, Vertex, Global Blood Therapeutics, CP reports honoraria from Novartis, and expert consultancy for Addmedica and Global Blood Therapeutics. The other authors declare no conflicts of interest regarding this paper. The authors confirm that the PI for this paper is Celine Delestrain and that the PI had direct clinical responsibility for patients. All the data used in this study are available upon request to the corresponding author. Table S1. Characteristics of the study population. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

L’allogreffe de moelle familiale HLA-identique (MRT) à conditionnement myéloablatif (MAC) permet de guérir plus de 95 % des enfants atteints de drépanocytose. Chez l’adulte, les greffes MAC sont associées à une incidence plus élevée de maladie du greffon contre l’hôte (GVHD) et de décès toxiques et moins de 20 % des patients (pts) sont greffés après 15 ans. Les greffes à conditionnement réduit permettent de diminuer la toxicité mais ont un risque de rejet plus élevé. Pour les pts ne disposant pas d’un donneur familial HLA-identique, les greffes haplo-identiques à conditionnement réduit peuvent être une alternative. Nous rapportons une série de 60 patients adolescents ou adultes greffés pour drépanocytose dans une unité d’hématologie Adolescents Jeunes adultes. Soixante pts (médiane âge : 18 ans, extrêmes : 14–39) allogreffés pour drépanocytose de juin 2010 à mai 2023 ont été inclus. Trois modalités de greffe ont été utilisés : HLA identique (MRT) après un MAC (busulfan/endoxan/ATG, n = 15), MRT à conditionnement non myéloablatif (NMA) (irradiation à 3 grays et alemtuzumab, n = 21) et greffe haplo-identique à conditionnement réduit (irradiation 2 grays, ATG, endoxan, fludarabine, ± thiotepa) avec endoxan post-greffe (n = 24). Les critères d’évaluation principaux étaient la survie globale (SG) et la survie sans drépanocytose (SSD). La SSD était définie à partir de la date de la greffe jusqu’au décès ou à l’apparition d’un chimérisme donneur < 20 % (réchec de la greffe). Le suivi médian était de 29 mois (IQR : 13–58). Greffe HLA identique : chez les 36 pts, la SG à 3 ans était à 100 % (95 % CI :100–100 %) sans décès. Un rejet était survenu après MAC et 2 après greffe NMA : survie à 3 ans sans drépanocytose après MAC 93,3 % (95 % CI :81–5–100 %) et après NMA 90,5 % (95 % CI :78,8–100 %). Deux de ces patients ont été regreffés avec succès et le troisième est en attente d’une seconde greffe. Après greffe MAC l’incidence de GVHD > II était de 20 % sans GVHD chronique modérée à sévère. Après greffe NMA aucun patient ne présentait de GVHD. La toxicité hématologique est faible après greffe NMA (durée médiane PNN < 0,5 G/L : 2 jours (extrêmes 0–17), nombre médian de transfusion de plaquettes 0 (extrêmes 0–5). En l’absence de rejet, 90 % des patients avaient un chimérisme mixte sur les globues blanc après greffe NMA, versus chez 54 % après MAC. Cependant, dans plus de 90 % des cas, du fait d’un avantage sélectif des érythroblastes du donneur, il existe chez les patients une normalisation de l’hémoglobine et des paramètres d’hémolyse, et un taux d’HbS similaire au donneur. En l’absence de rejet, les patients n’ont pas présenté de complications post-greffe en rapport avec la drépanocytose. Greffe haplo-identique : parmi les 24 patients, la survie à 3 ans est de 88,5 % (95 % CI :74,1–100 %) (1 décès par GVHD et 1 infection tardive à pneumocoque) et la SSD à 3 ans est de 78,1 % (95 % CI :60,5–100 %)(2 rejets). L’incidence de GVHD > II est de 17 % et de GVHD chronique modérée/sévère de 12 %. Cette série est la plus large expérience en Europe de la greffe chez les adolescents et adultes drépanocytaires. Ces données encourageantes des greffes HLA-identiques devraient conduire à proposer plus largement et précocement ce traitement à ces patients. L’approche de greffe non myéloablative est séduisante du fait de sa faible toxicité et de son absence de GVHD, mais un suivi à long terme est nécessaire pour s’assurer de la stabilité de prise de greffe. Malgré une toxicité plus importante, la greffe haplo-identique, réalisable grâce à la moelle d’un demi-frère ou sœur ou des parents < 60 ans, est une approche intéressante dans les formes sévères sans donneur génodientique qui devrait être discutée avant l’existence d’atteintes irréversibles d’organes. .

Le syndrome thoracique aigu (STA) est responsable d’une morbi-mortalité élevée chez l’enfant atteint de drépanocytose. Il est défini par la combinaison de signes cliniques tels que la fièvre, les douleurs thoraciques et les signes respiratoires associés à l’apparition d’un nouvel infiltrat ou opacité à la radiographie thoracique (RT). Cette dernière peut détecter cette complication mais doit être répétée pour une détection plus précoce, ce qui expose les enfants à des radiations importantes. L’échographie pulmonaire (EP) est une modalité d’imagerie non irradiante qui peut être intéressante pour le diagnostic et la détection précoce du STA. L’objectif de cette étude était de déterminer la précision de l’EP dans la détection des lésions pulmonaires précoces évocatrices du STA chez les enfants drépanocytaires hospitalisés pour une crise vaso-occlusive (CVO), par rapport à la RT, qui est le gold standard. Étude prospective multicentrique (encore en cours) menée dans 4 services pédiatriques d’Île-de-France entre le 01/04/2019 au 01/09/2021 incluant des patients drépanocytaires âgés de 1 à 18 ans hospitalisés pour une CVO. Des cliniciens experts ont effectué une EP à l’admission et durant les premiers 4 jours d’hospitalisation et l’ont comparée à la RT effectuée au 4e jour ou avant si l’enfant présentait des signes cliniques évocateurs de STA. Un score d’aération a été calculé pour chaque échographie réalisée. La précision, la sensibilité, la spécificité, les rapports de vraisemblance et la valeur prédictive positive et négative ont été calculés pour les caractéristiques de performance de l’EP, avec la RT comme imagerie de référence. Une EP a été réalisée chez 121 patients drépanocytaires hospitalisés pour une CVO. La prévalence du STA dans notre étude était de 16,5 % (20/121). L’âge moyen des patients STA était 9,25 ans ± 4,34. Trente pour cent des STA étaient de sexe féminin. Tous les patients ayant un STA avaient des consolidations sur leur EP au 4e jour d’hospitalisation et 93 % d’entre eux à l’admission j0 ou au premier jour d’hospitalisation j1. Globalement, la sensibilité de l’EP pour le diagnostic de STA était de 100 % et la spécificité était de 40 % par rapport à la RT. Un score d’aération ≥ 8 et/ou une profondeur de la consolidation ≥ 0,9 cm avaient le meilleur compromis de sensibilité et de spécificité à j2. Alors qu’un score d’aération ≥ 8 et/ou une profondeur de la consolidation ≥ 0,95 cm avaient le meilleur compromis de sensibilité et de spécificité à j3. L’EP semble être un outil utile, précis et réalisable pour la détection précoce des STA pendant l’hospitalisation des patients drépanocytaires présentant une CVO, par rapport à la RT.

L’allogreffe de moelle osseuse (MO), seul traitement curateur de la drépanocytose, est proposé chez l’enfant et adolescent présentant une forme sévère malgré un traitement intensifié. Une altération de la fonction respiratoire peut s’observer dans les suites d’une greffe de moelle chez des patients atteints d’hémopathies malignes sans que l’on connaisse actuellement l’effet sur la fonction respiratoire de patients greffés pour drépanocytose. L’objectif de cette étude est d’évaluer la fonction respiratoire des enfants et adolescents allogreffés pour drépanocytose. Il s’agit d’une étude rétrospective incluant les enfants et adolescents ayant été traités par greffe géno-identique pour drépanocytose entre 1990 et 2016 suivis au centre de référence de l’hôpital Intercommunal de Créteil. Ils devaient avoir eu au moins une évaluation de leur fonction respiratoire après la greffe et avoir été suivis cliniquement au moins quatre ans après la greffe. Une analyse en sous-groupe a été réalisée chez les enfants et adolescents qui avaient bénéficié d’explorations fonctionnelles respiratoires (EFR) avant la greffe. Leur EFR avant la greffe a été comparée à leur EFR la plus récente après la greffe afin d’évaluer l’évolution de leur fonction respiratoire. Cent huit patients ont été inclus, l’EFR la plus récente était réalisée après un délai médian de 6 ans post-greffe. La majorité (84 %) des enfants et adolescents présentaient une fonction respiratoire normale. Bien que tous les patients soient asymptomatiques à distance de l’allogreffe, 17 patients présentaient une fonction respiratoire post-greffe anormale avec un profil restrictif (8 %), obstructif (6 %) ou mixte (0,9 %). Quarante-quatre patients ont bénéficié d’EFR avant et après la greffe, et aucune différence significative n’a été constatée pour les paramètres de la fonction respiratoire : volume expiratoire maximal par seconde (VEMS), capacité vitale forcée (CVF), rapport VEMS/CVF, capacité vitale (CV), capacité pulmonaire totale (CPT) avant et après la greffe pour chaque patient. Seule la capacité de diffusion du monoxyde de carbone corrigée par l’hémoglobine (DLCOc) s’améliorait significativement après l’allogreffe. L’allogreffe de MO chez des enfants ou adolescents atteints de drépanocytose ne semble pas s’associer à une altération de leur fonction respiratoire et permet une amélioration de leur DLCOc.

Background Kaplan-Meier (KM) estimated cumulative incidence of silent cerebral infarcts (SCI) in a SCA-newborn cohort with sickle cell anemia (SCA) early screened by transcranial-color-Doppler-ultrasound (TCD-US) was shown to be high, despite initiation of chronic transfusion (CT), in children detected at risk by TCD, i.e., 28.2% by age 8, 37.4% by age 14, and an incidence of 3.4/100 patient-years (Bernaudin et al Blood 2011). We hypothesized that adding early extracranial Internal Carotid Artery (eICA) assessment would contribute to reducing SCI incidence. Patients and Methods TCD-US was systematically performed since May 1992 in our pediatric sickle cell anemia (SCA) cohort. Cerebral MRI/MRA was assessed every two years after age 5, or earlier in children on CT for abnormal time-averaged mean velocity (TAMV). eICA-color-Doppler-ultrasound and neck-MRA were added since June 2011. The highest TAMV in middle, anterior, posterior, basilar, intra and extracranial internal carotid cerebral arteries were recorded. Abnormal intracranial and eICA TAMV were defined as ≥ 200 cm/s and ≥ 160 cm/s, respectively. Stenosis was defined as a ≥ 25% decrease in the lumen of arteries. SCI was defined as an hyperintensity focus of at least 3 mm diameter, visible in two planes on FLAIR MRI. Genetic markers (alpha and beta genes, G6PD activity) and baseline biological parameters were recorded during the 2nd year of life before intensive therapy, and away from crisis and transfusion. Hospitalizations, annual check-up data, Doppler, MRI/MRA assessments and events (abnormal-TAMV, intra or extracranial stenosis and SCI) were prospectively recorded. CT was systematically applied in children with TAMV ≥ 200 cm/s for any artery and children with normalized TAMV and no stenosis were switched to hydroxyurea (HU) with CT overlap until reaching the maximal tolerated dose. For children with eICA TAMV 160-199 cm/s, neck-MRA was performed, and CT applied in those with eICA-stenosis while the others were given HU. Moreover, HU was initiated in children with frequent crises or baseline hemoglobin < 7g/dL. Stem cell transplantation was performed in children with cerebral vasculopathy and in those with frequent crises despite HU treatment. Cerebral arteriopathy was defined by history of abnormal intracranial or eICA TAMV or of intra or extracranial stenosis. Results We analyzed data updated in 7/2019 from stroke-free SCA children, born between 11/1992 and 8/2015, all assessed with cerebral MRI/MRA, including neck-MRA (n=338). Median (range) age at first and last cerebral MRI was 5.3 (1.8-16.6 yr) and 11.1 (2.8-19.9 yr), respectively, providing 3866 patient-years of MRI follow-up. SCI occurred in 65/388 SCA-children at median age of 6.4 (1.8-17.9 yr). Incidence of SCI was 65/3866 or 1.7/100 patient-years. The KM-estimated cumulative incidence of SCI was 15.1% (95%CI: 10.9-19.3%) by age 8 and 25.7% (95%CI: 19.7-31.7%) by age 14. Intracranial and isolated eICA-arteriopathies were present in 110/338 and 54/338 patients, respectively. SCI were significantly associated with the presence of intra or extracranial arteriopathy (Fisher test, p=0.013) as 41/65 children with SCI had intra or extracranial arteriopathy (20 isolated intra, 15 isolated extra and 6 intra and extracranial), while in the other 24 patients, 5 had history of conditional TAMV, 11 of acute anemia and 8 of recent acute chest syndrome. At first cerebral MRI, the multivariate Cox regression analysis retained as significant and independent predictive risk factors for SCI, baseline high reticulocyte count [HR=1.005 (95%CI: 1.002-1.008); p=0.004] and LDH [HR=1.001 (95%CI :1.001-1.002); p=0.001]. Discussion This long-term longitudinal study shows a reduction of the risk of SCI with time. The addition of eICA-assessment allowed the detection of isolated extracranial arteriopathy in 54 patients, with 15 who had SCI. The earlier HU initiation reducing the risk of ACS, acute anemia and hemolytic rate, along with detection of isolated eICA assessment and the use of transplantation in children with cerebral arteriopathy have most likely contributed to this overall improvement. Nevertheless, we suggest that initiating CT in patients with eICA-TAMV 160-199 cm/s, even in the absence of eICA stenosis, as done for intra- and extracranial-TAMV ≥ 200 cm/s, could further reduce SCI risk. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Background: Presence of Howell-Jolly bodies is associated with splenic dysfunction which progressively appears during aging or after splenectomy in patients with sickle cell disease. Improvement of splenic function has been found in several transplanted patients for SCD (Ferster 1993, Bernaudin 2007) encouraging our team to propose partial splenectomy to patients with hypersplenism and available matched-sibling donor. Aims: The goal of the present study was to evaluate the outcome of the splenic function from birth to adult age and the impact of splenectomy (partial or total) in SCD patients transplanted or not. Patients and Methods: In the pediatric Créteil SCD-cohort, including 907 SCD patients (111 SC, 47 Sb+, 725 SS, 21 Sb0 and 3 SDPunjab), Howell-Jolly bodies score (from 0 to 4) was prospectively assessed and recorded at each annual check-up. This study included 5013 annual check-ups (637 in SC/Sb+ and 4376 in SS/Sb0 patients) from Jan 1991 to July 2019. Results: Howell-Jolly bodies mean score increased during aging in SCD patients but was significantly lower in SC/Sb+ than in SS/Sb0 patients at each age of assessment (Figure 1). During the 2nd year of life, mean (SD Howell-Jolly bodies score was 0.34 (0.61) in SC/Sb+ vs 0.69 (0.82) in SS/Sb0 (P=0.01) while during the 18th year it was 0.61 (0.61) in SC/Sb+ vs 1.33 (1.1) in SS/Sb0 children (P<0.001). Among 749 SCA children, 86 were splenectomized at mean (SD) age of 6.4 years (3.9). As expected, mean (SD) Howell-Jolly bodies score was significantly higher at check-up in splenectomized than in non-splenectomized SCA-patients: 1.73 (1.2) vs 1.1 (1.0), p<0.001. However, the difference between both populations decreased during aging because of the progressive functional splenic dysfunction in non-splenectomized patients (Figure 2) Among SCA-children, 138 were transplanted with matched sibling donor at mean (SD) age of 9.0 years (4.9y). At each age of assessment, Howell-Jolly bodies score was strongly significantly (p<0.001) lower in transplanted than in non-transplanted children (Figure 3). At check-up performed during the 18th year of life, mean (SD) Howell-Jolly bodies score was 1.57 (1.0) in 241 non transplanted vs 0.54 (0.9) in 70 transplanted children (p<0.001) and the score in transplanted children was significantly positively correlated with the age at transplant (r=0.335, p=0.002). Seven children with splenic sequestration history or hypersplenism and available MSD-donor had partial splenectomy before transplant in order to try to preserve splenic function. Mean (SD) Howell-Jolly bodies score was 1.83 (1.2) before and was nul after transplant in all seven children.Conclusion: This cohort study clearly shows that splenic dysfunction increases during aging in SCA children and that stem cell transplantation allows to preserve splenic function especially since the transplant is performed early. In children with indication of splenectomy for recurrent splenic sequestrations or hypersplenism who have an available matched sibling donor, the present study encourages to propose partial vs total splenectomy just before stem cell transplantation in order to preserve splenic function. References 1. Ferster et al, Blood 1993;81:1102 2. Bernaudin et al, Blood 2007;110:2749

Despite its high prevalence in children with sickle cell anemia (SCA), the pathophysiology of silent cerebral infarcts (SCI) remains elusive. The main objective of this study was to explore the respective roles of major determinants of brain perfusion in SCA children with no past or current history of intracranial or extracranial vasculopathy. We used a multimodal approach based notably on perfusion imaging arterial spin labeling (ASL) magnetic resonance imaging (MRI) and near infra-red spectroscopy (NIRS), as well as biomarkers reflecting blood rheology and endothelial activation. Out of 59 SCA patients (mean age 11.4±3.9 yrs), eight (13%) had a total of 12 SCI. Children with SCI had a distinctive profile characterized by decreased blood pressure, impaired blood rheology, increased P-selectin levels, and marked anemia. Although ASL perfusion and oximetry values did not differ between groups, comparison of biological and clinical parameters according to the level of perfusion categorized in terciles showed an independent association between high perfusion and increased sP-selectin, decreased red blood cell deformability, low hemoglobin F level, increased blood viscosity and no a-thalassemia deletion. NIRS measurements did not yield additional novel results. Altogether, these findings argue for early MRI detection of SCI in children with no identified vasculopathy and suggest a potential role for ASL as an additional screening tool. Early treatment targeting hemolysis, anemia and endothelial dysfunction should reduce the risk of this under diagnosed and serious complication.

The risk of stroke in children with sickle cell disease (SCD) is detected by abnormal intracranial arterial time-averaged mean of maximum velocities (TAMVs ≥200 cm/s). Recently, extracranial internal carotid artery (eICA) arteriopathy has been reported, and a cross-sectional study showed that eICA-TAMVs ≥160 cm/s are significantly associated with eICA kinkings and stenosis. The cumulative incidence of and predictive risk factors for intracranial arteriopathy are well described in sickle cell anemia (SCA=SS/Sβ0) but are lacking for SC/Sβ+ children, as is the cumulative incidence of eICA arteriopathy. We report a prospective longitudinal cohort study including 493 children with SCD (398 SCA, 95 SC/Sβ+), all assessed by transcranial and cervical color Doppler ultrasound. Cerebral MRI/MRA data were available in 375 children with SCD and neck MRA in 365 children. eICA kinkings were defined as eICA tortuosities on neck MRA, with an internal acute angle between the two adjacent segments <90°. The median follow-up was 10.6 years. The cumulative incidence of kinkings was significantly lower in SC/Sβ+ children than in children with SCA, and no SC/Sβ+ child developed intra- or extracranial stenotic arteriopathy. The 10-year KM estimate of cumulative incidence (95% CI) for eICA-TAMVs ≥160 cm/s revealed its development in the 2nd year of life in children with SCA, reaching a plateau of 17.4% (13.2–21.6%) by about 10 years of age, while the plateau for eICA stenosis was 12.3% (8.3–16.3%). eICA assessment identified 13.5% (9.3–17.7%) patients at risk of stroke who were not detected by transcranial color Doppler ultrasound. We also show, for the first time, that in addition to a congenital origin, eICA kinkings sin patients with SCD can develop progressively with aging as a function of eICA-TAMVs, themselves related to anemia severity. Ongoing hydroxyurea treatment was significantly associated with a lower risk of abnormal intracranial arteriopathy and eICA kinkings. After adjustment with hydroxyurea, baseline low hemoglobin, high reticulocyte, and WBC counts remained independent risk factors for intracranial arteriopathy, while low hemoglobin and SEN β-haplotype number were independent risk factors for extracranial arteriopathy. The association between extracranial arteriopathy and SEN β-haplotype number suggested a genetic link between the ethnic origin and incidence of eICA kinkings. This prospective cohort study shows the importance of systematically assessing the eICA and of recording biological parameters during the 2nd year of life before any intensive therapy to predict the risk of cerebral arteriopathy and treat patients with severe baseline anemia.

Background: The presence of Howell-Jolly bodies (HJB) is associated with splenic dysfunction that appears progressively during aging or after splenectomy in patients with sickle cell disease (SCD). Improvement of splenic function has been found in several SCD patients after transplantation, prompting our team to propose a partial splenectomy prior to transplantation to patients with hypersplenism and available matched-sibling donor (MSD) Aims: To evaluate splenic function from birth to adulthood, the impact of intensive treatments: hydroxyurea (HU), chronic transfusion (CT), transplantation and compare the impact of splenectomy (partial/total) in SCD patients when transplanted or not Methods: Scores for HJB (0 to 3) were assessed on blood smears in the pediatric Créteil SCD-cohort and prospectively recorded at each annual check-up. This study included 4103 annual check-ups with available HJB score and all other biological parameters: Hb, HbA%, HbS%, HbF%, platelets etc. performed in 907 SCD patients (111 SC, 47 Sb+, i.e 158 SC/Sb+) and (725 SS, 21 Sb0 and 3 SDPunjab, i.e. 749 SCA-children) from January 1991 to January 2014 Results: HJB scores increased with aging in SCD patients, but were significantly lower in SC/Sb+ than in SS/Sb0 patients at each assessment age, P<0.001 (Figure 1). Multivariate logistic regression analysis showed that genotype (SCA vs SC/Sb+), splenectomy history and age at check-up were all strong significant (P<0.001) and independent risk factors for HBJ score >1 (>0.2% RBCs containing HJBs). Among 749 SCA (SS/Sb0) children, 86 were splenectomized at the mean age (SD) of 6.4 years (3.9). As expected, HJB score was significantly higher at check-ups in splenectomized than in non-splenectomized SCA-patients, P<0.001 (Figure 2). Among SCA-children, 138 were transplanted with MSD at a mean age (SD) of 9.0 years (4.9). At each age of assessment, HJB score was strongly significantly lower in transplanted than in non-transplanted children (p<0.001), (Figure 3) and the score in transplanted children was significantly positively correlated with the age at transplant (r=0.335; p=0.002). In non-splenectomized SCA-children, mean (SD) HJB scores were unexpectedly significantly higher (P<0.001) in patients on HU 1.39 (0.91) than in not-intensified 1.11 (0.82), in those on CT 1.09 (0.86) and in transplanted children 0.35 (0.7) (Figure 4). Multivariate analysis showed that on HU, HbF and MCV were inverse independent significant risk factors for HBJ score>1 (p<0.001). Seven children with splenic sequestration history or hypersplenism and available MSD-donor had partial splenectomy before transplant performed at mean (SD) age of 5.9 years (1.8). The mean (SD) HJB score was 1.83 (1.2) before and was null after transplant in the seven children Image:Summary/Conclusion: The higher number of RBCs containing HJBs observed on HU is intriguing and could be related to altered erythropoisesis kinetics, drug-induced genotoxicity or altered splenic function because of drug-induced high MCV. This cohort study clearly shows that splenic dysfunction increases with aging in SCA children and that stem cell transplantation allows to preserve splenic function, especially if the transplant is performed early. In children with indication of splenectomy for recurrent splenic sequestrations or hypersplenism who have an available MSD, the present study suggests that partial splenectomy just before stem cell transplantation may be useful to preserve splenic function.

In these two short reports, the authors approach the issue of whether hydroxyurea (HU) use in young males has major irreversible effects on sperm production. Joseph et al analyzed and compared sperm parameters in male patients with sickle cell disease (SCD) who were exposed or not exposed to HU before puberty. They report semen abnormalities in all patients but no differences between groups. Independently, Gille et al provide evidence for the lack of in vivo HU-related decreases in the spermatogonial pool in biopsy specimens from young males with SCD but evidence for a negative effect of SCD itself. Together, these reports suggest that the use of HU in young males does not adversely affect fertility.

Chez l'enfant, l'impact de la maladie drépanocytaire et l'effet de l'exposition du testicule à l'hydroxyurée (HU) sur la spermatogenèse ultérieure sont mal connus [1], [2], [3], [4]. Quantifier le pool de spermatogonies de patients prépubères atteints de drépanocytose ayant été préalablement exposés ou non à l'HU. Trente patients prépubères drépanocytaires ont bénéficié d'une congélation de tissu testiculaire entre 2010 et 2019, avant un conditionnement pré-allogreffe de cellules souches hématopoïétiques. La détection et le compte des spermatogonies ont été réalisés par l'immunomarquage de la protéine MAGE-A4 (Melanoma-Associated Antigen 4). Le ratio S/T (spermatogonies/tube séminifère) et le pourcentage de tubes séminifères contenant des cellules de Sertoli seules (SCO) ont été calculés. Les résultats ont été comparés aux valeurs de référence établies en fonction de l'âge sur une cohorte de patients sains [5] et entre les patients exposés ou non à l'HU. Les patients drépanocytaires de cette cohorte (4,2-15,0 ans) présentaient une diminution significative du pool de spermatogonies comparé aux valeurs de référence (p < 0,0001). Aucune différence n'a été mise en évidence entre les 17 patients exposés à l'HU (dose médiane de 22 mg/kg/jour, temps d'exposition médian de 36 mois), et les 13 patients non-exposés (S/T = 2,5 ± 3,3 vs 1,7 ± 0,6, p = 0,61 ; %SCO= 42 ± 21 vs 38 ± 16, p = 0,52) ; et ce quel que soit le délai (0,0 à 36,9 mois) entre la dernière exposition à l'HU et le prélèvement testiculaire. Cette analyse quantitative du pool de spermatogonies de patients drépanocytaires prépubères, la plus importante jamais rapportée, permet de mettre en évidence une diminution significative du nombre de spermatogonies chez ces patients sans observation d'un effet délétère supplémentaire lié au traitement par HU. Ces résultats sont en faveur d'une introduction du traitement dès que nécessaire chez l'enfant, sans crainte d'une atteinte additionnelle du testicule immature.