Search

Relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the most frequent cause of post-transplantation mortality. Isolated extramedullary (EM) relapse (iEMR) after HSCT is relatively rare and not well characterized, particularly in pediatric patients. We retrospectively analyzed 1527 consecutive pediatric patients with acute leukemia after allo-HSCT to study the incidence, risk factors, and outcome of iEMR compared with systemic relapse. The 5 -year cumulative incidence of systemic relapse (either bone marrow [BM] only or BM combined with EMR) was 24.8%, and that of iEMR was 5.5%. The onset of relapse after allo-HSCT was significantly longer in EM sites than in BM sites (7.19 and 5.58 months, respectively; P =.013). Complete response (CR) 2 +/active disease at transplantation (hazard ratio [HR], 3.1; P

WOS: 000426572200004, PubMed ID: 28179213, Objective: This study aimed to define the status of juvenile myelomonocytic leukemia (JMML) patients in Turkey in terms of time of diagnosis, clinical characteristics, mutational studies, clinical course, and treatment strategies. Materials and Methods: Data including clinical and laboratory characteristics and treatment strategies of JMML patients were collected retrospectively from pediatric hematology-oncology centers in Turkey. Results: Sixty-five children with JMML diagnosed between 2002 and 2016 in 18 institutions throughout Turkey were enrolled in the study. The median age at diagnosis was 17 months (min-max: 2-117 months). Splenomegaly was present in 92% of patients at the time of diagnosis. The median white blood cell, monocyte, and platelet counts were 32.9x10(9)/L, 5.4x10(9)/L, and 58.3x10(9)/L, respectively. Monosomy 7 was present in 18% of patients. JMML mutational analysis was performed in 32 of 65 patients (49%) and PTPN11 was the most common mutation. Hematopoietic stem cell transplantation (HSCT) could only be performed in 28 patients (44%), the majority being after the year 2012. The most frequent reason for not performing HSCT was the inability to find a suitable donor. The median time from diagnosis to HSCT was 9 months (min-max: 2-63 months). The 5-year cumulative survival rate was 33% and median estimated survival time was 30 +/- 17.4 months (95% CI: 0-64.1) for all patients. Survival time was significantly better in the HSCT group (log-rank p=0.019). Older age at diagnosis (>2 years), platelet count of less than 40x10(9)/L, and PTPN11 mutation were the factors significantly associated with shorter survival time. Conclusion: Although there has recently been improvement in terms of definitive diagnosis and HSCT in JMML patients, the overall results are not satisfactory and it is necessary to put more effort into this issue in Turkey.

We report the national data on the outcomes of hematopoietic stem cell transplantation (HSCT) for thalassemia major (TM) patients in Turkey on behalf of the Turkish Pediatric Stem Cell Transplantation Group. We retrospectively enrolled 1469 patients with TM who underwent their first HSCT between 1988 and 2020 in 25 pediatric centers in Turkey. The median follow-up duration and transplant ages were 62 months and 7 years, respectively; 113 patients had chronic graft versus host disease (cGVHD) and the cGVHD rate was 8.3% in surviving patients. Upon the last visit, 30 patients still had cGvHD (2.2%). The 5-year overall survival (OS), thalassemia-free survival (TFS) and thalassemia-GVHD-free survival (TGFS) rates were 92.3%, 82.1%, and 80.8%, respectively. cGVHD incidence was significantly lower in the mixed chimerism (MC) group compared to the complete chimerism (CC) group (p < 0.001). In survival analysis, OS, TFS, and TGFS rates were significantly higher for transplants after 2010. TFS and TGFS rates were better for patients under 7 years and at centers that had performed over 100 thalassemia transplants. Transplants from matched unrelated donors had significantly higher TFS rates. We recommend HSCT before 7 years old in thalassemia patients who have a matched donor for improved outcomes., Turkish Society of Pediatric Hematology, We would like to thank Vedat Uygun for contributing to the statistics of the study. This study was supported by the Turkish Society of Pediatric Hematology.

Background: The use of unmanipulated haploidentical hematopoietic stem cell transplantations (haplo-HSCT) with post-transplant cyclophosphamide (PTCY) in children has emerged as an acceptable alternative to the patients without a matched donor. However, the timing of calcineurin inhibitors (CNIs) used in combination with PTCY is increasingly becoming a topic of controversy. Method: We evaluated 49 children with acute leukemia who underwent unmanipulated haplo-HSCT with PTCY according to the initiation day of CNIs (pre- or post-cyclophosphamide [CY]). Results: There were no significant differences in the overall survival analysis between the 2 groups. The cumulative incidence of relapse at 2 years was 21.2% in the pre-CY group and 38.9% in the post-CY group (p = 0.33). Cytokine release syndrome (CRS) was observed more frequently in the post-CY group (p = 0.04). The overall survival and event-free survival at 2 years in patients with and without CRS in the pre-CY group were 42.9% versus 87.5% (p = 0.04) and 38.1% versus 87.5% (p = 0.04), respectively. Conclusion: Our study shows that the argument for starting CNI administration after CY is tenuous, and the rationale for not starting CNIs before CY needs to be reconsidered.

Uygun, Vedat ; Karasu, Gulsun Tezcan (isu author) Deficiency of the CD40L, expressed on the surface of T lymphocytes, is caused by mutations in the glycoproteinCD40L (CD154)gene. Resulting defective humoral and cellular responses cause a clinical presentation that includes recurrent sinopulmonary bacterial infections, opportunistic infections, sclerosing cholangitis, neutropenia, and autoimmune manifestations. HSCT represents the only curative treatment modality. However, the therapeutic decision to use HSCT proves challenging in many cases, mainly due to the lack of a phenotype-genotype correlation. We retrospectively reviewed patients with CD40L deficiency who were transplanted in Antalya and Goztepe MedicalPark Pediatric HSCT units from 2014 to 2019 and followed by Akdeniz University School of Medicine Department of Pediatric Immunology. The records of eight male cases, including one set of twins, were evaluated retrospectively. As two transplants each were performed on the twins, a total of ten transplants were evaluated. Conditioning regimens were predominantly based on myeloablative protocols, except for the twins, who received a non-myeloablative regimen for their first transplantation. Median neutrophil and platelet engraftment days were 13 (range 10-19) and 14 (range 10-42) days, respectively. In seven of ten transplants, a CMV reactivation was developed without morbidity. None of the patients developed GVHD, except for one mild case of acute GVHD. All patients survived, and the median follow-up was 852 days. Our data show that HSCT for patients with CD40 ligand deficiency is a potentially effective treatment for long-term disease control. WOS:000541941200001 32573870 Q4

KILIC, SUAR CAKI/0000-0001-7489-2054; Hazar, Volkan/0000-0002-1407-2334 Uygun, Vedat ; Karasu, Gulsun Tezcan (isu author) Background Despite the increasing performance of allogeneic hematopoietic cell transplantation over the last decades, graft-versus-host disease (GVHD) remains the main cause of morbidity and mortality. The efficacy of ruxolitinib against GVHD has been demonstrated in adult studies; however, very few studies have been conducted in children. Procedure This study aimed to evaluate the efficacy of ruxolitinib in 29 children with steroid-refractory acute or chronic GVHD. Twenty-five (87%) patients received at least three different immune modulator agents, including methylprednisolone, before initiating ruxolitinib. Results All grade 2 acute GVHD patients completely responded to ruxolitinib treatment; 82% of high-grade (3-4) acute GVHD patients and 80% of chronic GVHD (moderate-severe) patients had at least a partial response. Of seven patients with bronchiolitis obliterans, five had a partial response after ruxolitinib. Of 29 patients, 22 were administered steroids at any time in the first month of acute GVHD or the first three months of chronic GVHD during ruxolitinib usage, which was significantly tapered by the end of the observation period. Conclusion Steroid-refractory acute and chronic pediatric GVHD patients treated with ruxolitinib had a high overall response rate, with the additional benefit of steroid sparing. WOS:000509125100001 31981413 Q1