Relevance . Allogeneic hematopoietic stem cell transplantation (allo-HSCT) makes it possible to treat severe malignant and non-malignant hematopoietic disorders system. Pulmonary complications (PC) occur in 40–60 % of patients after allo-HSCT. However to date, the effect of HSCT on functional and morphological pulmonary changes in recipients remains insufficiently studied. The objective of current study was to evaluate risk factors affecting long-term survival in children and adolescents after allo-HSCT. Methods and materials . The current study was both retrospective and prospective. The analysis included 362 patients with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML), aged 5 months to 18 years, who received allo-HSCT at Raisa Gorbacheva Memorial Research Institute for Pediatric Oncology, Hematology and Transplantation in 2000–2018. All the patients underwent chest computed tomography (CT). When detecting CT changes, we performed fibrobronchoscopy (FBS) with microbiological examination of bronchoalveolar lavage (BAL). Results . PC were diagnosed in 124 patients (64 %) who received allo-HSCT in 2014–2018. Decrease of overall survival (OS) is associated with PC development during the first year after allo-HSCT(р<0,001).The development of early PC in remission of the underlying disease significantly affected OS (p=0.001).The probability of PC development is 2.26 times higher in patients older than 9 years (p=0.006). When comparing the intensity of conditioning regimens (MACvsRIC) in remission of the underlying disease, we did not get significant differences in the incidence of PC (p>0.05). Graft source, donor type, HLA-compatibility, recipient gender did not affect the incidence of PC (p>0.05). When using graft-versus-host disease (GVHD) prophylaxis (ptCYvsATG), the 5-year OS in patients without PC was 78.8 % and 62.8 %respectively. The 5-year OS in patients with PC was 51.8 % and 42.4 % respectively (р=0.007). Decrease of OS in patients with PC is associated with chGVHD(58.3 %,) (р=0.03). Conclusion . Pulmonary complications (infectious and non-infectious) in allo-HSCT recipients are more likely to occur in the first year after transplantation. Among bacterial pathogens, the predominance of Gr(-) flora remains. The incidence of pulmonary complications was significantly lower when using ptCY as a prevention of GVHD.

Pleuropulmonary blastoma (PPB) is a very rare tumor of childhood that arises from the mesenchyme of the lung and is associated Infant acute lymphoblastic leukemia (ALL) is characterized by a high incidence of KMT2A gene rearrangements and poor outcome. Despite intensified therapy protocols, infant ALL remains a difficult-to-treat disease, with a high relapse rate. Allogeneic bone marrow transplantation is the only curative method aimed to curing the disease. Over the last decades, donor lymphocyte infusion (DLI) has been used as a salvage therapy after post-transplant relapses in B-ALL patients with a proven antileukemic effect. The combination of blinatumomab and DLI is a promising immunoadoptive therapy for resistant ALL based on the induction of “graft versus leukemia” effect by activating donor T-lymphocytes. We analyzed the results of combined immunoadoptive therapy with a bispecific T-cell activator blinatumomab and DLI in 3 infants with ALL, as well as the outcome of monotherapy with a bispecific T-cell activator in one infant. The study was approved by the Independent Ethics Committee and the Scientific Council of the I.P. Pavlov First Saint Petersburg State Medical University. All infants initially had the KMT2A gene rearrangement and were classified as high-risk. The indication for immunoadoptive therapy was an early combined relapse of the disease after haploidentical hematopoietic stem cell transplantation in one patient and minimal residual disease (MRD) in three patients. All patients achieved long term hematological remission of the disease, 3 (75%) patients – MRD negative remission. The median duration of bone marrow response was 24 (8–63) months. One patient developed a bone marrow relapse in 8 months after therapy, two patients developed isolated extramedullary relapse. We did not see toxic complications and induction of graft-versus-host disease during immunoadoptive therapy. At the time of the follow up, all patients are alive, three remains in lasting hematological remission.

Профилактические инфузии донорских лимфоцитов используют у пациентов с высоким риском развития рецидива заболевания после алло-ТГСК. Данные по безопасности раннего введения ИДЛ у детей крайне ограничены. В работе отражены частота клинически значимой реакции «трансплантат против хозяина» (РТПХ) и ее связь с общей и безрецидивной выживаемостью. Проанализированы 37 детей с острыми лейкозами и ЮММЛ, получивших профилактические ИДЛ в течение первых 6 месяцев после алло-ТГСК. Развитие острой/хронической РТПХ средней степени выявлено у 7 из 37 детей (19%), не отмечено тяжелых форм РТПХ. Наиболее часто диагностировали кожную форму хронической РТПХ в сочетании с поражением печени. Случаи летальности, связанные с осложнениями после ИДЛ, не были зарегистрированы. Напротив, индукция острой/хронической РТПХ улучшала показатели безрецидивной выживаемости и не влияла на общую выживаемость, p=0,04 и p=0,3 соответственно. Prophylactic donor lymphocytes infusion (DLI) is used in patients with a high risk of relapse after allo-HSCT. The data about safety of early start DLI in children are extremely limited. This study demonstrates the incidence of clinically significant graft versus host disease (GVHD) and correlation with overall and disease-free survival. We analyzed 37 children with acute leukemia and JMML, who had received prophylactic DLI within the first 6 months after HSCT. Moderate acute/chronic GVHD was diagnosed in 7/37 children (19%), nobody developed severe GVHD. The most children had chronic GVHD with involvement of skin and liver. There were no cases GVHD-related mortality. The induction of acute/chronic GVHD improved the relapse-free survival and did not influence on overall survival, p=0.04 and p=0.3, respectively.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative therapy for patients with acute myeloid leukemia (AML). The conditioning regimen administered for this patient based on busulfan (Bu) combined with cyclophosphamide (Cy), fludarabine (Flu) or some other agents. Comparisons of myeloablative conditioning (MAC) versus reduced intensity conditioning (RIC) have demonstrated a various results between relapse and toxicity in a few reports. We suppose, that dose intensity of Bu across regimens may affect treatment outcomes. Aim of this retrospective study was to evaluate the impact dose of busulfan to overall survival (OS), transplant-related mortality (TRM), relapse-free survival (RFS), toxicity, the incidence of primary graft failure and acute "graft versus host" disease (GvHD) in transplantation in children and adolescents with AML. The study was approved by the Independent Ethics Committee and the Scientific Council of the I.P. Pavlov First Saint Petersburg State Medical University. We analyzed 110 AML pediatric patients with the median age 9 (range 1–19) y.o., who underwent first allo-HSCT with Bu based conditioning in R.M. Gorbacheva Memorial Institute from 2002 to 2018. Patients were divided into 3 groups: Bu1 – patients, who received Bu at the dose 8–10 mg/kg, n = 34 (31%), in Bu2 – dose of Bu was 12 mg/kg, n = 35 (32%), in Bu3 – dose of Bu was > 12 mg/kg, n = 41 (37%). In Bu1 Bu was combined with Flu in 31 (91%) pts and Cy in 3 (9%); in Bu2 – with Flu in 12 (34%), Cy in 7 (20%) and other agents in 16 (46%); in Bu3 – with Cy in 32 (78%), with Flu in 7 (17%) and other agents in 2 pts (5%) (p < 0.001). Patients in Bu2 received more Cy based GvHD prophylaxis regimens (69% vs 44% in Bu1, vs 29% in Bu3, p = 0.003) and more haplo grafts (51% vs 29% in Bu1, vs 15% in Bu3, p = 0.003). The complete remission at the HSCT was observed in 79 % in Bu1, 49% in Bu2, 61% in Bu3 (p = 0.02). Probabilities of OS, RFS, TRM were estimated by using the Kaplan–Meier method. Incidence of toxicity, acute GvHD and primary graft failure – by using Mann–Whitney U-test. Transplant engraftment was achieved in 95 (86%) of patients. Graft failure occurs in the 5 patients of Bu1 group (15%), in the 6 pts of Bu2 (17%) and in the 4 pts of Bu3 (10%) (p = 0.7). Median follow-up was 2 years for Bu1 and Bu3, 1 year for Bu2. Two-year OS was similar (Bu1 = 59% vs Bu2 = 60% vs Bu3 51%, p = 0.7). Two-year OS of pts with CR before HSCT was 70% in Bu1, 82% in Bu2, 60% in Bu3, p = 0,3 and 14%, 39%, 38% for pts with progression disease (PD), respectively (p = 0.5). Two-year RFS was 74% in Bu1, 82% in Bu2, 64% in Bu3 at CR (p = 0.4); 43%, 39% and 38% in pts with progression, respectively (p = 0.9). Median of RFS were also similar for the pts in PD (4 months in Bu1, 5 months in Bu2 and Bu3, p = 0.9) and not achieved for pts at CR. Drug related toxicity grade III–IV 4 experienced in 35% pts in Bu1, 29% in Bu2, in 54% in Bu3 (p = 0.04). Mucositis and toxic hepatitis were the most common adverse events. Sinusoidal obstruction syndrome (SOS) experienced in 8 pts from different group: 4 from Bu2 (11%), 3 from Bu3 (7%) and only pts from Bu1 (3%) with previously treated of inotuzumab (p = 0.4). The most pts with VOD (3/5) had PD at the HSCT. Cumulative incidence of acute GvHD grade 2 (15% vs 14% vs 10%, p = 0.8) were not different. Acute GvHD grade III–IV was observed a bit more often in Bu3 (34%), than in Bu1 (18%) and Bu2 (17%) (p = 0.09). TRM up to D+100 was also higher in Bu3 (15%), than in Bu2 (6%) and Bu1 (0%) (p = 0.05). The transplant results of children with similar disease status of AML, received MAC or RIC conditioning with various dose of Bu, were not associated with significant differences in overall outcomes. The higher dose Bu may increase incidence of toxicity grade III–IV (p = 0.04) and acute GvHD grade III–IV (p = 0.09) with increasing of early TRM (p = 0.05).

Acute and chronic steroid-refractory graft-versus-host disease (srGVHD) is a life-threatening complication of allogeneic stem cell transplantation. There are a number of reports on case series describing efficacy of ruxolitinib in both acute and chronic srGVHD. We conducted a prospective study (NCT02997280) in 75 patients with srGVHD (32 acute, 43 chronic, 41 adults, and 34 children). Patients with chronic GVHD had severe disease in 83% of cases, and acute GVHD patients had grade III–IV disease in 66% of cases. The overall response rate (ORR) was 75% (95% CI 57–89%) in acute GVHD and 81% (95% CI 67–92%) in chronic. Overall survival was 59% (95% CI 49–74%) in acute group and 85% (95% CI 70–93%). The major risk factors for lower survival were grade III–IV gastrointestinal involvement (29% vs 93%, p = 0.0001) in acute form and high disease risk score in chronic (65% vs 90%, p = 0.038). Toxicity was predominantly hematologic with 79% and 44% of grade III–IV neutropenia in acute and chronic groups, respectively. There was no difference between adults and children in terms of ORR (p = 0.31, p = 0.35), survival (p = 0.44, p = 0.12) and toxicity (p > 0.93). The study demonstrated that ruxolitinib is an effective option in acute and chronic srGVHD and can be used both in adults and children.

Aсute myeloid leukemia (AML) in children aged 0–2 years and aсute lymphoid leukemia (ALL) up to 1 year (i.e., infants) frequently characterize high risk and poor prognosis. Аllogeneic hemopoietic stem cell transplantation (аllo-HCST) is a main curative but toxic option for these patients, and choice of allogeneic donor may be one of the important factor for long-term survival. Aim. To evaluate overall survival (OS), relapse free survival (RFS), transplant related mortality (TRM), "graft versus host" disease free/relapse free survival (GRFS) in infant with acute leukemia underwent allo-HCST from MUD vs haplodonor at 1st or 2nd remission. The study was approved by the Independent Ethics Committee and the Scientific Council of the I.P. Pavlov First Saint Petersburg State Medical University. 34 children with infant acute leukemia: 23 pts with AML (68%) and 11 – with ALL (32%) – underwent allo-HSCT from MUD vs haplo at 1st or 2nd remission between 2004–2018 were analyzed. Median age at allo-HCST – 22 months (6 months – 5 y.o.). HSCT was performed from MUD in 19 (56%) pts (group 1), haplo – 15 (44%) pts (group 2). Myeloablative conditioning received 29 (85%) pts. Reduced intensity conditioning received 5 (15%) pts. Posttransplant cyclophosphomyde (PtCy) was used in 10 (53%) pts in the group 1 and 14 (93%) pts. in the group 2 (p = 0.043). Engraftment was identified in 18 pts (95%) of group 1 and 12 pts (80%) of group 2 (p = 0.28). At the median follow up 3.5 years OS is 79% in the group 1 аnd 73% in the group 2 (p = 0.68). RFS is 79% in the group 1 аnd 67% in the group 2 (p = 0.41). GRFS is 39% in the group 1 аnd 47% in the group 2 (p = 0.5). TRM occurred in 2 pts (11%) of group 1 (due to infectious and toxicity) and no one of the group 2 (p = 0.2). Haplo-HSCT with PtCy is a good alternative to MUD with high efficacy and acceptable toxicity in children with infant acute leukemia at 1st or 2nd remission.

Haploidentical transplantation (Haplo-HSCT) is an effective method for treating patients with high-risk acute leukemias (AL) who do not have HLA-matched related (MRD) and matched unrelated donors (MUD). During 10 years in our centre more than 150 Haplo-HSCT were done. More than 50% of patients with resistant disease or resistant relapse – «salvage group» patients. 106 patients with high-risk AL, median age – 7 y.o. (range 0–18), acute lymphoblastic leukemia (ALL) – 63 (59,4%), acute myeloid leukemia (AML) – 43 (40,6%), received Haplo-HSCT from December 2006 till December 2016. Forty three patients (40,6%) recived Haplo-HSCT in complete remission (CR): CR1 21 (49%) patients, CR2 – 13 patients (30%), CR3 – 9 (21%). Resistance disease or resistance relapse AL – 63 (59,4%) patients. Сonditioning regimens were as follows: MAC «GIAC» – 39 (36,8%) patients, MAC based on Busulfan 12 mg/b.w. and Fludarabine 150 mg/mg (2) – 2 (2%), MAC reduced toxisity based on Treosulfan 42 g/m (2) – 6 (5,7%), RIC based on Melfalan 140 mg/m(2) – 40 (37,7%), RIC with Busulfan 8mg/b.w. – 18 (17%). All patients received prophylaxis of acute graft versus host disease (aGVHD). Seroprophylaxis with ATG – ATGAM 60 mg/b.w. – 39 (36,8%), posttransplant cyclophosphomide 50 mg/b.w. on D+3, D+4 – 67 (63,2%). Conventional immunosuppressive therapy: tacrolimus – 47 (44,3%) patients, CsA – 59 (55,7%). Source of transplant – combined unmanipulated stimulated Haplo-bone marrow plus manipulated (positive selected CD34+) stimulated CD34+ cells × 27 (25,5%) patients and unmanipulated stimulated Haplo-bone marrow – 79 (74,5%). Stem cells dose of unmanipulated stimulated Haplo-bone marrow transplant CD34+ × 10(6)/b.w. median – 5,9×10(6)/b.w., stem cells dose of combined transplant median 5,9×10 (6)/b.w. (range from 2,5 till 30,9×10(6)/b.w. Statistical analysis: SPSS Statistics v.17. Overal survival (OS) was defined as time from study enrollment to death, with living patients censored on the date of the last follow-up. The Kaplan–Meier method was used to estimate OS rates, and the exact log-rank test was used to compare survival curves. Survival estimate are reported with standard errors determined by the method of Peto and Pike.

Результаты аллогенной трансплантации гемопоэтических стволовых клеток от гаплоидентичного донора с применением неманипулированного трансплантата у детей и подростков, страдающих острыми лейкозами высокой группы риска: опыт 10 лет наблюдения

Background. Despite of modern methods of diagnosing, prevention and treatment, invasive fungal disease (IFD) remains actual problem after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Data of IFD in adolescents and young adults (15–25 y.o.) after allo-HSCT are limited. The aim of the study was to estimate of incidence, etiology, clinical signs and outcome of IFD in adolescents and young adults recipients of allo-HSCT. Materials and methods. In retrospective single center study from Jan 2013 to Dec 2014 were included 80 pts after first allo-HSCT in the clinic of Raisa Gorbacheva Memorial Research Institute of Children Oncology, Hematology and Transplantation, First Pavlov State Medical University of St. Petersburg. EORTC/MSG 2008 criteria for IFD diagnosis were used. “Active IFD” means IFD diagnosed just before HSCT. Results. Incidence of IFD before allo-HSCT was 18.8 % (n = 15): invasive aspregillosis (IA) (n = 11), invasive candidiasis (IC) (n = 3) and 1 patient had two IFD (IA + IC). Complete response to antifungal therapy was in 40 %, partial – 26.7 %, “active” IFD – 33.3 %. Secondary antifungal prophylaxis was made predominantly with voriconazole (80%). Patients without IFD before HSCT (n = 65) received primary antifungal prophylaxis predominantly with fluconazole (85 %). Cumulative incidence of IFD-events at 1 year after allo-HSCT was 15 %, at 2 years – 18.8 % including new cases of IFD (n = 14) and relapse of IFD (n = 1) after allo-HSCT with median day of oncet +43 (14–577). Incidence of IA was 15 %, IC – 2.5 %, pneumocystis pneumonia (PCP) – 1.25 %. IFD risk factors after allo-HSCT (< 0.05) were: age < 18 years, non-malignant diseases, active disease at the moment of HSCT, neutropenia grade IV more than 20 days, acute “graft-versus-host” disease. First-line therapy were: IA – voriconazole (58.3 %), IC – echinocandins (100 %), PP – co-trimoxazole (100 %). 12-weeks overall survival (OS) from day of IFD diagnosis after allo-HSCT was 93.3 %, IA – 91.7 %. All patients with IC and PCP alive. 100-days OS after allo-HSCT was 85 %, 2-year OS after allo-HSCT – 67.5 %. There was no difference in OS in patients with or without IFD before allo-HSCT. Conclusion . Incidence of IFD in adolescents and young adults before allo-HSCT was 18.8 %. Only one patient relapsed with IA after allo-HSCT. Incidence of IFD after allo-HSCT (1 year) was 15 %. The main IFD was invasive aspergillosis. 12-weeks overall survival from IFD diagnosis after allo-HSCT was 93.3 %. IFD before and after allo-HSCT did not impair the outcome of the transplantation in adolescents and young adults.