INTRODUCTION:Preformed, high-titer anti-human leukocyte antigen (HLA) antibodies remain a major barrier to successful kidney transplantation, increasing the risk of early graft loss and prolonged time on dialysis. Despite advances in desensitization, current therapies are largely ineffective for patients with extremely high antibody levels. METHODS:Here, we report the case of a 37-year-old woman with kidney failure secondary to NPHS2-related nephrotic syndrome who received no suitable transplant offer despite 20 years of active listing, owing to extreme HLA sensitization (calculated Panel Reactive Antibody [cPRA] over 99.9%). She had previously been transplanted from age six to 17. Following the failure of a daratumumab-based desensitization regimen four years earlier, immunologic evaluation indicated the need for concurrent, potent depletion of memory B cells and plasma cells. This prompted a salvage regimen, administered under compassionate use, combining a type II humanized anti-CD20 antibody (obinutuzumab) with a B-cell maturation antigen (BCMA)-targeted T-cell engager (elranatamab). RESULTS:Both agents were well tolerated; only a transient, asymptomatic cytokine release syndrome occurred after the initial elranatamab dose. The combination produced a profound reduction in anti-HLA antibodies, decreasing the cPRA from 99.96% to 0% within six months. Protective immunity was maintained with immunoglobulin replacement. Apart from a self-limited episode of sapovirus-induced diarrhea, no infectious events occurred. Following successful desensitization, the patient underwent an uneventful kidney transplantation across low-level donor-specific antibodies (DSAs), which did not rebound post-transplant. The immunosuppressive regimen consisted of non-lymphodepletive induction with basiliximab, followed by a triple-drug maintenance therapy, including a prompt conversion from mycophenolic acid to everolimus. At ten months post-transplant, she remained free of rejections, with excellent graft function, low urinary chemokine levels, and persistently negative donor-specific antibodies. CONCLUSIONS:This dual-agent immunotherapeutic strategy achieved unprecedented depletion of high-titer, preformed anti-HLA antibodies and represents a promising approach for patients with prohibitive sensitization.

Management of pulmonary mucormycosis includes intravenous liposomal amphotericin-B (L-AmB), followed by posaconazole or isavuconazole. We aimed to determine the optimal L-AmB duration before switching to triazole therapy. Using data from a retrospective study in France, we performed an emulated trial evaluating stopping L-AmB after 14 days (short treatment) versus continuing L-AmB (long treatment). The benefit of combination L-AmB therapy was also investigated. A cloning, censoring, and weighting approach was used to account for immortal time and indication biases. Ninety-four cases of pulmonary mucormycosis were included, of which 35% had dissemination. Eighty-nine patients received L-AmB first-line therapy for a median of 25 (IQR: 12-54) days, including 18 patients as combination therapy. L-AmB was discontinued for adverse events in 16/89 patients (18%). Treatment was switched to posaconazole (n = 38) or isavuconazole (n = 9) in 47 cases and was switched back to L-AmB due to disease progression in 11/47 (23%) cases. Overall, the 180-day mortality was 54%. Diagnosis in the ICU, dyspnea at diagnosis, disseminated disease, and ground-glass opacities on chest CT scan were associated with increased mortality. No difference in 180-day survival was found between patients receiving short or long L-AmB treatment (HR=0.80, 95% CI [0.29-1.99]) and between patients receiving L-AmB alone or in combination (HR=1.14, 95% CI [0.56-2.32]) in emulated trials, although confidence intervals were wide. Switching to triazole therapy after 14 days of L-AmB treatment was as effective as longer durations while reducing L-AmB side effects. Combination therapy did not improve prognosis. These results could inform randomized clinical trials assessing different first-line therapeutic strategies for pulmonary mucormycosis.

Abstract FLT3 internal tandem duplications (FLT3-ITD) are major genetic events in acute myeloid leukemia (AML). Although the clinical impact of FLT3-ITD “macroclones” (allelic ratio [AR] ≥0.05) is well established, the significance of low-level FLT3-ITD subclones (“microclones”) remains uncertain. We conducted a post hoc analysis of 1733 patients with newly diagnosed AML enrolled in the Backbone Intergroup 1 trial (ClinicalTrials.gov identifier: NCT02416388). Using next-generation sequencing (NGS), we detected FLT3-ITD microclones (AR between 0.0004 and 0.05) in 17.4% of patients without FLT3-ITD macroclones. Microclones and macroclones (low and high AR) were independently associated with increased relapse risk (cause-specific hazard ratio, 1.50 [95% confidence interval (CI), 1.18-1.91]; 1.98 [1.50-2.62]; and 2.33 [1.69-3.22], respectively) after adjustment for age, white blood cell count, other gene mutations, midostaurin treatment, and allogeneic hematopoietic stem cell transplantation. At 2 years, the cumulative incidence of relapse reached 42.5% (95% CI, 37.0-47.9) in patients with macroclones, 45.1% (38.3-51.6) in patients with microclones, and 29.4% (26.6-32.3) in patients without FLT3-ITD. In NPM1-mutated AML, both microclones and macroclones were associated with higher levels of measurable residual disease (MRD) and increased relapse risk, without independent impact on overall survival after adjustment for MRD. An analysis of paired samples further revealed that 41.8% of relapses in patients with FLT3-ITD microclones at diagnosis were associated with a macroclone at relapse. These findings challenge current risk stratification models and support the integration of NGS-based FLT3-ITD detection into the diagnostic and prognostic workflow for AML. Prospective trials addressing the management of patients with FLT3-ITD microclones are warranted, as is their consideration in future European LeukemiaNet guidelines.

Abstract In the OPTIFIL study that included 39 patients with localized invasive pulmonary aspergillosis complicating hematological malignancies, Aspergillus-specific IFN-γ-producing T cells were detectable in 41% of the patients and predicted better 6-week outcomes, while their absence correlated with uncontrolled disease. Lymphopenia was the main limitation to Aspergillus ELISpot assay interpretation.

Abstract Advanced systemic mastocytosis (AdvSM), comprising aggressive systemic mastocytosis, mast cell leukemia, and systemic mastocytosis with an associated hematological neoplasm, is a heterogeneous myeloid neoplasm with poor prognosis. Allogeneic hematopoietic cell transplantation (allo-HCT) remains the only potentially curative treatment, yet its benefit across AdvSM subtypes in the era of KIT-targeted tyrosine kinase inhibitors (TKIs) such as midostaurin and avapritinib remains unclear. To identify patient subgroups benefiting from allo-HCT and to define prognostic factors for post-transplant survival, we analyzed 631 AdvSM patients from the European Competence Network on Mastocytosis registry, including 69 who underwent allo-HCT. Treatment effects were assessed using time-dependent Cox regression in a transplant-eligible complete-case cohort ( n = 419). In this cohort, allo-HCT showed no overall survival (OS) benefit (hazard ratio [HR] 1.21, 95% CI 0.80–1.84; p = 0.37), whereas TKI response emerged as a strong independent predictor of survival (HR 0.42; p <0.001). Subtype-stratified analysis revealed an allo-HCT benefit exclusively in patients with systemic mastocytosis associated with acute myeloid leukemia ( n = 30; HR 0.20; p = 0.020). Among the 69 transplanted patients, median OS was 49.6 months with 2-year and 5-year survival of 63% and 46%, respectively. The International Prognostic Scoring System for Mastocytosis (IPSM) at transplantation independently predicted both OS (HR per category 1.68; p = 0.026) and progression-free survival (HR 1.99; p = 0.003), whereas the Mutation-Adjusted Risk Score and diagnostic subtype did not reach statistical significance. Competing risk analysis demonstrated that higher IPSM captured both relapse-related and transplant-related mortality. These findings suggest that the survival benefit of allo-HCT in AdvSM is driven primarily by control of the associated myeloid neoplasm. Accordingly, allo-HCT should be prioritized in patients with SM-AML, whereas TKI-directed strategies may be preferred in other subtypes, with IPSM at transplantation potentially guiding transplant selection and timing.

La forme pulmonaire de la réaction de greffon contre l’hôte (GVH) se manifeste par une atteinte fibrosante des bronches (syndrome de bronchiolite oblitérante ou BOS) ou du parenchyme (pneumopathie interstitielle). Elle concerne entre 5 et 10 % des patients allogreffés et son pronostic reste réservé. Au cours de cette seizième session des ateliers d’harmonisation des pratiques en allogreffe, nous avons rappelé les définitions et critères diagnostiques de la GVH pulmonaire, discuté des différents traitements à notre disposition et de la place de la transplantation pulmonaire. Nous avons souligné l’insuffisance des critères diagnostiques actuellement reconnus et la nécessité de les réviser pour un dépistage plus précoce de la BOS. Nous avons rappelé les recommandations de suivi fonctionnel en post-allogreffe. De nouveaux traitements ont été développés pour le traitement de la GVH : inhibiteur de Janus kinase (ruxolitinib), de rhokinase (bélumosudil) ou anticorps anti-CSF1R (axatilimab). Leur efficacité spécifique sur la GVH pulmonaire est difficile à déterminer par manque d’études axées sur la fonction respiratoire. Nous avons discuté de leur place par rapport aux traitements inhalés, aux corticostéroïdes systémiques et à la photophérèse extracorporelle. La transplantation pulmonaire est une option à envisager en cas de forme sévère réfractaire aux traitements. Les patients allogreffés représentent une faible proportion des patients transplantés pulmonaires, alors que les résultats sont les mêmes que dans une autre indication. Nous avons rappelé les conditions dans lesquelles un sujet atteint de GVH pulmonaire devrait être référé à un centre expert de transplantation pulmonaire.

Supplementary Figures S1-S10, Supplementary Table Legends

IntroductionInborn errors of interferon response factors (IRFs) are a subset of monogenic inborn errors of immunity, occurring as a result of damaging variants in the IRF genes. Of these diseases, IRF4 deficiencies are associated with the broadest range of phenotypes, each of which is highly genotype dependent. In 2023, our consortium characterized seven patients carrying the IRF4 p.T95R variant, which was demonstrated to be damaging through various models. The clinical profile of these patients has not been described in detail.MethodsThis study summarizes our understanding of IRF4 p.T95R in all nine known patients, including two patients new to this report. Key features were extracted from clinical records, publications, and follow-up with clinicians, with a focus on pretransplant infectious susceptibility and treatment outcomes, particularly following hematopoietic stem cell transplant (HSCT).Results7/9 patients are male, with ages ranging from 6.5 to 31 years at last update. All had opportunistic infections before 1.5 years of age. Notable pretransplant opportunistic infections included Pneumocystis jirovecii (8/9), cytomegalovirus (CMV) (3/9), onychomycosis (3/9), and weakly virulent mycobacteria (2/9). 5/9 patients also had gastrointenstinal (GI) manifestations, including colitis, proctocolitis, and mucosal eosinophilia. All had combined immunodeficiency with notable defects in B cell development and antibody production (9/9 hypo/agammaglobulinemia). All patients received immunoglobulin replacement therapy and antimicrobial prophylaxis. 4/9 patients received HSCT. Of those transplanted, one had good outcomes (i.e., resolution of enteropathy and protection from infections), 2/4 died (pretransplant CMV and cryptosporidium), and 1/4 lost their graft. In those managed without transplant, 2/9 have reached adulthood (20 and 31 years at last update).ConclusionThis cohort of 9 patients with combined immunodeficiency due to heterozygosity for IRF4 p.T95R experienced a spectrum of outcomes. IRF4 p.T95R patients all have profound combined immunodeficiency, characterized by classic opportunistic infections early in life. HSCT is potentially curative (n = 1). Active infection at the time of transplant was associated with poor outcomes, further emphasizing the value of early recognition and intervention. The phenotype of IRF4 p.T95R is uniquely severe when compared to the growing list of IEIs affecting IRF4, emphasizing the critical need to consider IRF4 genotype-specific effects in IEI patients.Figure 1.Clinical features and transplant outcomes of IRF4 p.T95R patients. (A) IRF4 p.T95R cohort. *Awaiting first transplant. (B) Phenotypes of IRF4 p.T95R patients. (C) Survival timelines for IRF4 p.T95R patients. (D) Transplant outcomes for IRF4 p.T95R patients. (E) HSCT donor types. MUD, matched unrelated donor. **Patient received multiple grafts, including grafts from haploidentical and MUD.

PURPOSE:Biallelic variants in the minor spliceosomal gene RNU4ATAC were successively identified in Taybi-Linder/Microcephalic osteodysplastic primordial dwarfism type I, Roifman, and Lowry-Wood syndromes, which are characterized by variable microcephaly, short stature, neurodevelopmental impairment, skeletal dysplasia, and immunodeficiency. Two-thirds of the reported individuals present with Taybi-Linder syndrome, the first-described and most severe form. METHODS:We collected clinical and molecular data from individuals with biallelic RNU4ATAC variants through various French and European networks and clinics to refine the phenotypic spectrum of RNU4ATAC-opathies. RESULTS:We enrolled 69 participants and identified 18 new pathogenic variants. We report a significant proportion of attenuated or atypical presentations, novel rare symptoms, and, unexpectedly, a broad spectrum of autoimmune or inflammatory manifestations, affecting nearly half of the participants. Integrating our data with the 109 published cases, we propose a novel classification based on the main manifestations, immunodeficiency, and microcephalic primordial dwarfism. Using computer-assisted facial analysis, we also demonstrated the existence of a specific dysmorphic pattern in RNU4ATAC-opathies that is distinct among some sub-syndromes. CONCLUSION:We present a large cohort of individuals with RNU4ATAC-opathies and expand the phenotypic spectrum to paucisymptomatic forms, indicating that these diseases are likely to remain underdiagnosed.

The predictive value of cytokines (CK) for malignancy-associated adult hemophagocytic lymphohistiocytosis (M-HLHa) remains uncertain. We evaluated a cytokine-based Risk Score (RS) and the IL-10/IL-6 Ratio to predict M-HLHa. Adult patients (n = 112) from the French HLH cohort (NCT02113917) with complete data for nine key HLH related CK measured by Luminex were first analyzed. Logistic regression was performed, and a RS was subsequently derived and internally validated. In a post hoc analysis, the IL-10/IL-6 ratio obtained using the ELLA cytokine assay was evaluated in 75 patients, 54 of whom also had Luminex testing, plus 25 additional patients from the cohort. The RS and IL-10/IL-6 ratio were then jointly assessed in the 54 patients with results from both platforms. Among the 112 patients, 45 had M-HLHa and 67 non M-HLHa; median age was 48 years and 64 (57%) were male. Eight variables were associated with M-HLHa, of which four were retained in the logistic model: age > 48 years (2.9[1.12-7.33], p = 0.03), TNF-α ≤ 43 pg/mL (3.2[1.16-8.61], p = 0.02), IL-18 > 574 pg/mL (4.9[1.89-12.75], p = 0.001), and IL-10/IL-6 ≥ 1.5 (2.7[1.01-7.31], p = 0.04), with respective weights of 11, 12, 16, and 10. A RS ≥ 20 increased the odds of M-HLHa 17-fold (17.2 [5.4-54.5], p < 0.0001). The IL-10/IL-6 ratio alone (n = 75) showed good performance (AUC 0.83). In the 54 patients with both assays, the RS and IL-10/IL-6 ratio preserved their diagnostic performance (AUC 0.87 and 0.79, respectively). These data support the RS and IL-10/IL-6 Ratio as useful tools to improve the identification of M-HLHa in adults. Trial Registration: clinicaltrials.gov NCT02113917.

ABSTRACT:Chronic granulomatous disease (CGD) is an inborn error of immunity characterized by defective NAD phosphate oxidase function, leading to impaired microbial killing, recurrent infections, and granulomatous inflammation. Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for CGD, particularly effective when a fully HLA-matched donor is available. However, the place of HLA-haploidentical HSCT remains less established. This retrospective multicenter study analyzed outcomes of 64 patients with CGD (53 males; 46 with X-linked CGD) who underwent a first HSCT with HLA-haploidentical family donors, with either in vitro T-cell receptor (TCR)αβ/CD19 depletion or in vivo depletion using posttransplant cyclophosphamide (PTCY). The mean age at transplant was 5.8 years (range, 0-33). Patients exhibited a high disease burden before HSCT, with 45% experiencing infections in the 6 months before HSCT and 67% exhibiting inflammation. Outcomes in the entire cohort showed a 3-year overall survival, event-free survival (EFS), and grade 3 to 4 graft-versus-host disease (GVHD)-free EFS of 75.9%, 70.2%, and 56.1%, respectively, and were not affected by the type of depletion or age. The cumulative incidence (CI) of primary graft failure (PGF) was 20.6%. The CI of grade 2 to 4 acute GVHD was higher in the PTCY group (P = .04), whereas the CI of grade 3 to 4 GVHD was not. These results indicate that HLA-haploidentical HSCT is a feasible transplant option for patients with CGD lacking HLA-matched donors. Further refinement of transplant protocols is necessary to mitigate graft failure and acute GVHD, ultimately improving access and outcomes for this life-saving therapy.

In higher risk myelofibrosis patients, the only treatment able to improve survival and cure the disease is allogeneic hematopoietic stem cell (HSCT). However, not all potential candidates have a donor and it has been reported that transplantation from an HLA-mismatched donor gives disappointing results as compared to transplantation from an HLA matched donor. In this phase 2 trial (registered at clinicaltrial.com as NCT04728490), transplantation from an haplo-identical donor was proposed in patients without an HLA matched donor using fludarabine 30mg/m2/day (D) for 5 days – treosulfan 10g/m2/D for 3 days– thiotepa 5 mg/kg for one day– post-translant cyclophosphamide 50 mg/kg ion day +3 and day +5 (PTCY) -ciclosporine and mycophenolate mofetil plateform. The trial was sponsored by Hôpital Saint-Louis, APHP, Paris, France, with the financial support of MEDAC pharmaceutical and the scientific support and network of the French Society of Cellular Therapy (SFGM-TC). We conducted a single-arm phase 2 clinical trial to demonstrate that using an haplo-identical related donor will increase the relapse and rejection-free survival post-HSCT as compared to an historical cohort of patients received 9/10 HLA matched unrelated donor. Our hypothesis was that 1-year relapse and rejection-free survival could reach 55% instead of 30%. Using a 2-sided, one-sample log-rank test, with 90% statistical power and a 5% significance level, 28 patients had to be included. Secondary objectives were incidence of acute and chronic GVHD, hematological recovery, relapse, non-relapse mortality, severe infections and overall survival. Inclusion criteria were age 18-70 years, myelofibrosis, and at least two of the following characteristics: constitutional symptoms, hemoglobin level < 10g/dl, thrombocytopenia < 100G/L, peripheral blast > 1%, white blood cell (WBC) count > 25 G/L, poor cytogenetics (+8; -7/7q-;i(17q);-5;5q-;12p-;inv(3);11q23, and ECOG < 3. Follow-up was scheduled for 12 months and amended later to 24 months after transplantation. Results presented here are at one year endpoint. We included 29 patients in 15 French centres, one of whom did not receive the transplantation due to a fatal haemorrhage. Further analyses were based on the 28 transplanted patients; all patients are followed > 12 months, 3 patients are still followed-up on July 2025 to reach the 24th month. Median age at inclusion was 65 years (IQR: 58-67), 19 (68%) were men, 11 (39%) had general symptoms, 10 (36%) were transfusion dependant, 21 (75%) had hemoglobin level < 10 g/dl, 13 (46%) had platelet count < 100 G/L, 13 (46%) had peripheral blast >1%, 7 (25%) had WBC count >25 G/L, and 3/16 had a complex cytogenetic. 15 patients had grade 2 fibrosis, 12 grade 3 (and one unknown). Hematopoietic stem Cell Transplantation-Comorbidity Index was 0-1 in 20 (71%) patients and 2 or more in 8 (29%) patients. Among the 25 patients with NGS tested, 15(62%), 5 (21%) and one (4%) had JAK2V617F, CALR, and MPL mutation, respectively. Other genes frequently altered were ASXL1 (71%), TET2 (29%), EZH2 (25%) and RUNX1 (21%). Eighteen patients had primary myelofibrosis, 10 had secondary myelofibrosis. All the 28 patients received peripheral blood stem cells from their donor and cells were cryopreserved in 10 (36%) in the context of COVID-19 pandemia. One-year relapse and rejection-free survival was 64.3% (95%CI: 48.8-84.7), significantly above the historical rate of 35% in transplantation from a 9/10 unrelated donor. Cumulative incidence of grade 2-4 and grade 3-4 acute GVHD were 64.3% (95%CI: 43-79.4) and 25% (95%CI:10.8-42.2); 11 patients developed chronic GVHD, with 1-year cumulative incidence estimated at 39.3% (95%CI, 21.1-57.1). Cumulative incidence of neutrophils recovery on day 60 was 85.7% (95%CI: 63.9-94.8), and that of platelet recovery was 67.9% (46.4-82.2). One patient relapsed after HSCT, and 10 patients died due to viral pneumonia (SARS-COV-2, n=1 or influenza, n=1), multi-organ failure without documented infection (n=2), graft rejection/non engraftment (n=2), and acute GVHD (n=4). One-year overall survival was 67.9% (95%CI: 52.6 – 87.6). One-year non-relapse mortality (NRM) was 32.1% (95%CI: 15.8 – 49.7). In conclusion, the primary endpoint of one-year relapse and rejection -free survival was achieved. However, the NRM is the first cause of failure, mainly due to acute GVHD, MOF and infections justifying further investigations to reduce early toxicity.

Clinical laboratories searching for pathogenic variants focus mostly on the protein-coding region and corresponding essential splicing sites. Screening for variants in intronic regions requires dedicated bioinformatics tools and detailed experimental studies to confirm deleteriousness and pathogenicity. We report intronic variants in a cohort of eight patients from seven kindreds with unexplained inborn errors of immunity (IEI). Using ad hoc bioinformatics tools, we identified seven kindreds carrying three branchpoint variants at three loci (BTK, SH2D1A, and WAS) and four AG-gain acceptor site variants at another four loci (DOCK8, NFKB1, STXBP2, and UNC13D). The variants were located between positions −9 and −49 relative to the wild-type acceptor site. The deleteriousness and, thus, pathogenicity of these variants were confirmed by exon-captured transcriptome studies and flow cytometry analyses of protein production or function. Our findings indicate that intronic variants should be systematically screened and investigated, even in clinical laboratory settings.

Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (allo-HCT). Optimizing GVHD prevention strategies remains a key concern to improve patient survival and quality of life. In Europe, anti-thymocyte globulin (ATG) is widely used as GVHD prophylaxis. However, post-transplant cyclophosphamide (PTCy), initially introduced in the haploidentical transplant setting, has more recently been extended to mismatched unrelated donors (MMUD). In matched related (MRD) and matched unrelated (MUD) allo-HCT, studies comparing PTCy to the traditional ATG strategy have shown controversial results which do not allow a specific strategy to be recommended. Here, we report a representative analysis based on large national data to complement existing evidence. We retrospectively analyzed patients from the SFGM-TC registry who underwent a first allo-HCT from MRD or MUD for acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) between 2014 and 2022. Patients received GVHD prophylaxis with: immunosuppressive agents (IS) alone (group NONE), PTCy with or without (+/-) IS (group PTCy), ATG +/- IS (group ATG), PTCy+ATG +/- IS (group PTCy+ATG). We restricted our analysis specifically to allo-HCT with reduced intensity conditioning (RIC) and peripheral blood stem cells (PBSC). IS regimens included mainly calcineurin inhibitor (CNI) + antimetabolite (methotrexate or mycophenolate mofetil), or CNI alone. RIC regimens consisted in: Fludarabine+Busulfan, Thiotepa-Busulfan-Fludarabine (TBF), total body irradiation (TBI) based regimen, Baltimore like regimens, and other regimens. A total of 3702 patients were analyzed: group PTCy n=103, group ATG n=3340, group PTCy+ATG n=46 and group NONE n=213. The groups were comparable in age at allo-HCT, gender, disease type, remission status at transplant and HCT-CI score but differed significantly in transplant year, donor type, blood group compatibility, RIC regimen and IS regimen. Of note, in the PTCy and PTCy+ATG groups, 14% of allo-HCT were performed without additional IS, compared to 0% in the other groups. In the NONE group, 65% of allo-HCT used MRD donors versus 45% in the remaining groups. These variables (except transplant year) were included as adjustment factors in multivariable analysis. At day 100, the cumulative incidence of grade ≥ II acute GVHD (aGVHD) was 26%, 29%, 22% and 24% (p=0.169) and grade III-IV aGVHD was 8%, 10%, 7% and 6% (p= 0.333) in PTCy, ATG, NONE and PTCy+ATG groups respectively. At 2 years, the cumulative incidence of moderate-severe/extensive chronic GVHD (mod-ext cGVHD) was 14%, 19%, 28% and 26% in PTCy, ATG, NONE and PTCy+ATG groups respectively (p=0,012). In adjusted multivariable analysis, PTCy was associated with a significant reduction in grade III-IV aGVHD compared to ATG (HR 0.46, p=0.039). Regarding mod-ext cGVHD, PTCy and ATG were both significantly superior to NONE but PTCy seemed to be superior to ATG in lowering mod-ext cGVHD risk (HR 0.61, p=0.088). In addition, PTCy+ATG was not significantly different from other groups but the statistical power was limited by the small number of patients. The cumulative incidence of relapse (RI) at 2 year was 35%, 36%, 28% and 33% was in PTCy, ATG, NONE and PTCy+ATG groups respectively and not significantly different between groups. In multivariable analysis, PTCy group experienced a significantly lower non-relapse mortality (NRM) compared to NONE (HR 0.45, p=0.036) but did not differ with ATG group (HR 0.60, p=0.150). An analysis of toxicity patterns and causes of death will be presented. With a median follow-up of 17.6 months for the overall population, the 2-year OS, PFS and GRFS was 59.8% [58.1 - 61.5], 53.8% [52.1 - 55.6] and 42.3% [40.7 - 44.1] respectively. These outcomes were not significantly influenced by donor type (MRD and MUD) or by GVHD prophylaxis group in multivariable analysis. In conclusion, in this large retrospective cohort of MRD/MUD and RIC allo-HCT in AML/MDS, PTCy significantly reduced severe aGVHD compared to ATG, that might contribute to lower the NRM. However, no significant differences were observed between PTCy and ATG regarding cGVHD, RI, OS, PFS or GRFS. These results are consistent with previous studies explaining the overall trend toward a democratization of PTCy, although a robust international prospective randomized study would be necessary before changing current practices.

Non-Aspergillus invasive fungal infections (NAFI) are increasingly reported in patients with Chronic Granulomatous Disease (CGD), but precise clinical descriptions remain scarce. We conducted a retrospective analysis of NAFI cases among CGD patients in the French National Registry of Primary Immunodeficiencies (CEREDIH) and in a comprehensive literature review. We identified 16 proven NAFI (9 molds, 6 yeasts and 1 Pneumocystis) among 263 CGD patients from CEREDIH and included an additional 106 probable/proven NAFI from a literature review (75 molds, 29 yeasts, 1 Pneumocystis, 1 dimorphic). Mold NAFI occurred at a median age of 17 years [IQR 9–23], and were mostly located to the lungs (79

Introduction: FLT3 internal tandem duplications (ITD) are found in approximately 25% AML and defined by an allelic ratio (AR)≥0.05, hereinafter referred to as macroclones (Mclones). We previously described the prevalence of FLT3-ITD microclones (µclones), defined by an AR<0.05, in a cohort of patients with FLT3-ITD Mclones (Joudinaud, Blood Adv 2025). Here we aimed at assessing the prevalence and prognostic value of FLT3-ITD µclones in the French multicenter BIG-1 trial. Methods: The BIG-1 trial (NCT02416388) included patients (pts) aged 18-60 years with newly diagnosed AML treated by intensive chemotherapy (CBF-AML and APL excluded). This post-hoc analysis required DNA fragment analysis (FA) to detect FLT3-ITD Mclones (AR≥0.05). Samples with negative or AR<0.05 FA were used for NGS on a NovaSeq 6000. Regions of interest were sequenced with an average depth of 3000x then analyzed with FiLT3r algorithm for quantification of FLT3-ITD (Boudry, BMC Bioinformatics 2022) allowing an AR threshold detection at 4x10e-4. Patients with an AR 0.0004-0.05 were referred to µclones, other patients were considered without FLT3-ITD. Midostaurin (MIDO) has been introduced in 07/2018 according to its label. Results: 1,733 pts with available DNA were included in this analysis from 01/2015 to 02/2022, 353 (20.4%) had FLT3-ITD Mclones (±µclones, MACRO group) including 175 (49.6%) pts with high AR (≥0.5), 240 (13.8%) had FLT3-ITD µclones only (MICRO group) and 1,140 (65.8%) were FLT3-ITD negative. Overall, median age was 50y and 848 pts were female without differences between the three groups. As expected, according to ELN-2022, risk groups were favorable for 0.6%/40.9%/35.2%, intermediate for 82.4%/28.3%/15.8% and adverse for 17.0%/30.8%/49.0% of pts in MACRO, MICRO and negative groups, respectively. Among the 668 pts with NPM1 mutation, 237 (35.5%), 130 (19.4%) and 301 (45.1%) pts were in MACRO, MICRO and negative groups, respectively, with significant differences for each pairwise comparison. MIDO was administered to 134 patients (38%) in the MACRO group, 18 (7.5%) in the MICRO group, and 18 (1.6%) in the negative group, the latter two based on FLT3-TKD mutations. In multivariate analyses, compared to absence of FLT3-ITD, µclones were significantly and independently associated with an increased risk of relapse (sHR 1.46 [1.15-1.85]; P=0.002), as well as presence of FLT3-ITD Mclones (sHR 2.09 [1.65-2.66]; P<0.001), as a whole, or divided in two groups with low AR<0.5 (sHR 1.93 [1.46-2.56]; P<0.001) and high AR≥0.5 (sHR 2.36 [1.73-3.22]; P<0.001), adjusted for confounding factors including allo-SCT in CR1 as time-dependent variable. The other independent predictive factors in multivariate analyses for CIR were: age, cytogenetic risk, NPM1, CEBPA bZIP and TP53 mutations, MIDO and allo-SCT. 5y-CIR estimations were 47.5%, 47.9% and 37.5%, 2y-CIR estimations were 42.5%, 45.1% and 29.4% in MACRO, MICRO and negative groups, respectively. Presence of FLT3-ITD µclones was also significantly and independently associated with an increased risk of death or relapse (aHR: 1.39 [1.13-1.71]; P=0.002), as were Mclones with low and high AR. 5y-RFS were 41.9%, 40.6% and 47.7% in MACRO, MICRO or negative groups, respectively. Given the impact of FLT3-ITD mutations in the ELN 2022 risk definition of patients with NPM1 gene mutation, we conducted an analysis in this subgroup. In multivariate analyses, FLT3-ITD µclones were significantly and independently associated with increased CIR (sHR 1.66 [1.24-2.24]; P=0.001), shorter RFS (aHR 1.71 [1.29-2.27]; P<0.001) and shorter OS (aHR 1.48 [1.02-2.14]; P=0.04) compared to negative group. After two courses of chemotherapy, NPM1 BM MRD was ≥1% in 24.1%, 15.7%, 16.3% and 6.7% of pts in MACRO group with high and low AR, MICRO group and negative group respectively. Conclusion: In younger AML pts, FLT3-ITD microclones increase the risk of relapse and shorten RFS. In the NPM1 mutated subgroup, such FLT3-ITD microclones also shorten OS. Our results advocate for a change of practice from fragment analysis to high-sensitivity molecular techniques for FLT3-ITD detection, consider the mutation in the ELN classification regardless of the diagnostic threshold of 0.05 and investigate FLT3 inhibitors in this population.

Despite well-conducted replacement therapy with polyvalent immunoglobulins (IgRT), some patients with primary immunodeficiencies (PID) continue to experience recurrent or chronic infections. IgA and IgM, essential for mucosal and complement-mediated immunity, are absent or minimal in standard immunoglobulin products. The aim of this study is to evaluate the safety and clinical evolution profiles in PID patients with undetectable IgA/IgM levels and persistent infections despite standard IgRT, after introduction of an IgA- and IgM-enriched immunoglobulin preparation (IgGAM, Pentaglobin®). A compassionate use program (CUP) in France enrolled 20 PID patients with undetectable IgA/IgM levels, receiving IgGAM IV infusions every 7–14 days. Tolerance, infection frequency, hospitalizations, and biological markers (Ig levels, complement activation, salivary IgA) were analyzed prospectively. Twenty patients were included in the CUP at the time of analysis. No severe adverse event was reported. Half of the patients experienced mild to moderate hypersensitivity symptoms. Mean antibiotic courses dropped from 5.4 to 2.3/year (p = 0.0009) and mean number of hospitalizations decreased from 2.6 to 1.2/year (p = 0.01). Median serum IgA and IgM levels increased three months after IgGAM start. IgM and low levels of IgA were detected in saliva samples, suggesting at least a transient transfer of IgA/IgM from IgGAM into mucosal fluids. In patients with severe PID and undetectable IgA/IgM, IgGAM was associated with reduced infections and hospitalizations. Controlled studies are needed to confirm the benefit of IgA/M enriched immunoglobulin preparations in PID patients with persistent and/or recurrent respiratory or digestive infections.