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BackgroundDedicator of cytokinesis 8 (DOCK8) deficiency is the main cause of the autosomal recessive hyper-IgE syndrome (HIES). We previously reported the selective loss of group 3 innate lymphoid cell (ILC) number and function in a Dock8-deficient mouse model. In this study, we sought to test whether DOCK8 is required for the function and maintenance of ILC subsets in humans.MethodsPeripheral blood ILC1-3 subsets of 16 DOCK8-deficient patients recruited at the pretransplant stage, and seven patients with autosomal dominant (AD) HIES due to STAT3 mutations, were compared with those of healthy controls or post-transplant DOCK8-deficient patients (n = 12) by flow cytometry and real-time qPCR. Sorted total ILCs from DOCK8- or STAT3-mutant patients and healthy controls were assayed for survival, apoptosis, proliferation, and activation by IL-7, IL-23, and IL-12 by cell culture, flow cytometry, and phospho-flow assays.ResultsDOCK8-deficient but not STAT3-mutant patients exhibited a profound depletion of ILC3s, and to a lesser extent ILC2s, in their peripheral blood. DOCK8-deficient ILC1-3 subsets had defective proliferation, expressed lower levels of IL-7R, responded less to IL-7, IL-12, or IL-23 cytokines, and were more prone to apoptosis compared with those of healthy controls.ConclusionDOCK8 regulates human ILC3 expansion and survival, and more globally ILC cytokine signaling and proliferation. DOCK8 deficiency leads to loss of ILC3 from peripheral blood. ILC3 deficiency may contribute to the susceptibility of DOCK8-deficient patients to infections.

Background: In this study, we aimed to report long‐term follow‐up of our pediatric and adult patients with DCLRE1C (DNA cross‐link repair 1C) hypomorphic mutation who were diagnosed leaky severe combined immunodeficiency (SCID). Methods: Eighteen patients (13 children and five adults), aged between 6 and 29 years were included. Clinical and immunological features, including immunoglobulin levels, T and B cells, natural killer cell subsets, regulator T (Treg) cell ratios/markers, and cytokines, were assessed before and after hematopoietic stem cell transplantation (HSCT) and compared with healthy controls. Results: Recurrent infections (78%) and skin manifestations (61%) such as granulomatous skin lesions, warts, and vitiligo were the most common clinical findings. Autoimmune diseases were observed in 33% and malignancy in 17%. Most patients had low serum IgA and B‐ and T‐cell lymphopenia at the first admission. Recent thymic emigrants (RTE), Tnaive, Bnaive, CD56dimCD16+ cell ratios were significantly lower in the patients than in control; however, follicular helper T TFH and Th1 [interferon gamma (IFN‐γ)] cell ratios were significantly higher than the control. Although, Treg ratio and its functional receptors tend to be high but not significant. Eleven patients (61.1%) were treated with HSCT. Median follow‐up times of transplant patients was 56 (9–67) months. Conclusion: Patients with hypomorphic DCLRE1C mutations may present with variable clinical and laboratory findings at different ages. Our study showed a helper T (Th)1‐dominant immune response before and after HSCT. Increased IFN‐γ and TFH cells ratio could be a reason of chronic inflammation and autoimmunity developing before and after HSCT. Long‐term follow‐up of these patients after HSCT will help to better understand the disease and its pathophysiology. [ABSTRACT FROM AUTHOR]

Objectives: Graft‐versus‐host disease (GvHD) is one of the leading causes of morbidity and mortality in patients undergoing allogeneic HSCT, and effective prevention of GvHD is critical for the success of the HSCT procedure. Calcineurin inhibitors (CNI) have been used for decades as the backbone of GvHD prophylaxis. In this study, the efficacy and safety of Cyclosporine A (CsA) and tacrolimus (TCR) were compared in pediatric HSCT for thalassemia. Materials and Methods: This is a retrospective analysis of 129 pediatric patients who underwent HSCT with the diagnosis of thalassemia at Medicalpark Göztepe and Antalya Hospitals between January 2017 and December 2020. Results: Despite the GvHD prophylaxis, grade II–IV acute GvHD developed in 29 patients. Of these patients, 12 had only gut, 10 had only skin, 6 had combined gut and skin, and one had only liver GvHD. Fifteen of these 29 patients were in the CsA group, and 14 of them were in the TCR group. There was no significant difference between the groups in terms of acute GvHD occurrence, GvHD stage, or involvement sites. In terms of CNI‐related toxicity, neurotoxicity in 15 (CsA n = 9, TCR n = 6) and nephrotoxicity in 18 (CsA n = 4, TCR n = 14) patients were observed. While there was no difference between the two groups in terms of neurotoxicity, more nephrotoxicity developed in patients using TCR (p =.013). There was no significant difference between the groups in terms of engraftment syndrome, veno‐occlusive disease, CMV reactivation, PRES, or graft rejection. Conclusion: Regarding GvHD, there was no difference in efficacy between TCR and CsA usage. Patients taking TCR experienced noticeably higher nephrotoxicity in terms of adverse effects. This difference should be considered according to the patient's clinical situation while choosing a CNI. [ABSTRACT FROM AUTHOR]

Background. In a screening study conducted on adults, the prevalence of sickle cell traits in Antalya was found to be 0.24%. Since no screening studies have been conducted in the neonatal period in our region, the exact incidence has not been determined. In this study, we aim to report our experience of neonatal screening for sickle cell disease in Antalya, Türkiye. Methods. During a 14-month period, 2562 heel prick blood samples, taken on filter paper from Akdeniz University Hospital, Antalya Education and Research Hospital and Antalya Atatürk State Hospital and four other healthcare centers, were studied using the high pressure liquid chromatography method. Blood samples were studied using the 'Sickle Cell Short Program' test method on a Bio Rad Variant device. Results. In the study, no patients with sickle cell disease were identified. Four newborns who were sickle cell carriers (0.15%) and two newborns who were Hemoglobin D carriers (0.08 %), were found. Conclusion. Considering the efficiency and cost calculations made as a result of the data obtained from our study, it was concluded that sickle cell screening would not be effective in newborns. It seems more effective and economical to screen the children of parents, who are found to be at risk for Hemoglobin S carriage as a result of premarital tests. [ABSTRACT FROM AUTHOR]

Busulfan (BU)-based myeloablative conditioning is a standard conditioning regimen for children with AML; however, it is not clear yet which combination of cyclophosphamide (CY) and fludarabine (FLU) is most effective. We performed a study to compare the results of BUCY120 and BU-FLU in pediatric patients with AML in CR1 undergoing allo-HSCT from matched sibling donors. With the combination of BU, 15 patients were given 120 mg/kg of CY, and 12 patients were given 150 mg/m2 of FLU, respectively, in the condition regimen. Patients treated with BUFLU relapsed less than those treated with BUCY120 (p= 0.03). Moreover, these patients engrafted platelets earlier than the BUCY120 administered patients (p= 0.03). The frequency of complications in both groups was comparable. There was no significant difference in survival analysis between the groups. BUFLU has a low toxicity profile, making it a reasonable choice for children with AML in CR1 with low risk and a lower relapse frequency compared to BUCY120. [ABSTRACT FROM AUTHOR]

Background: Serine/threonine kinase 4 (STK4) deficiency is a combined immunodeficiency (CID) characterized by early onset recurrent bacterial, viral, and fungal infections. Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapy for CID; however, little is known about the necessity and benefits of HSCT in patients with STK4 deficiency. Methods: We report two siblings with STK4 deficiency transplanted from two unrelated donors with the same conditioning regimen. Results: In the conditioning regimen, rituximab was given on Day −11 (375 mg/m2), and sirolimus was added on the same day. Busulfan was administered at a myeloablative dose (3.2 mg/kg; Days −7 to −4) with 150 mg/m2 of fludarabine (Days −7 to −3). They were transplanted with peripheral blood stem cells, and graft‐versus‐host disease (GVHD) prophylaxis was administered with 10 mg/m2 methotrexate on Days 1, 3, and 6. In addition, mycophenolate mofetil (MMF) was started on Day 1 with ongoing use of sirolimus. We did not encounter veno‐occlusive disease (VOD), high‐grade acute GVHD, or significant organ toxicity in either patient. Both patients were well at the end of the first year after HSCT with complete donor chimerism. Conclusions: Serine/threonine kinase 4 deficiency is a disease with high mortality post‐HSCT; therefore, the conditioning regimen and GVHD prophylaxis strategies are important considerations in these patients. In our opinion, the conditioning regimen, which includes rituximab and busulfan and fludarabine (BU‐FLU), GVHD prophylaxis with sirolimus and MMF, and short‐term methotrexate, offers favorable outcomes and is well tolerated in our STK4‐deficient patients. [ABSTRACT FROM AUTHOR]

Background: Although there are many studies on the role of vitamin D deficiency (VDD) in hematopoetic stem cell transplantation (HSCT), outcomes have often reported conflicting results because of the heterogeneity of the patients in the studies. Methods: We investigated the association between VDD prior to HSCT and outcomes after HSCT in a relatively homogenous group of patients with thalassemia major (TM) who received identical treatment for TM before transplantation, and the same conditioning regimen and GVHD prophylaxis during and after transplantation. All patients, including the patients with normal vitamin D3 levels received 400 to 800 IU per day of vitamin D for the first 6 months after HSCT. Results: Pre‐HSCT VDD increased the frequency of aGVHD after transplantation, particularly in HSCTs performed with PBSC for the stem cell source. Pre‐transplant low vitamin D3 levels had no association with transplant outcomes such as engraftment, viral infections, alloimmunization, chronic GvHD, total days of hospitalization, and success in terms of transfusion independence. Conclusions: Low vitamin D3 levels before HSCT carry a significant risk for aGVHD. All patients with TM should be screened for VDD before HSCT, and every effort should be made to supplement vitamin D before the transplant in VDD patients. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Post‐transplant relapse has a dismal prognosis in children with acute leukemia undergoing allogeneic hematopoietic stem cell transplantation (allo‐HSCT). Data on risk factors, treatment options, and outcomes are limited. Procedure: In this retrospective multicenter study in which a questionnaire was sent to all pediatric transplant centers reporting relapse after allo‐HSCT for a cohort of 938 children with acute leukemia, we analyzed 255 children with relapse of acute leukemia after their first allo‐HSCT. Results: The median interval from transplantation to relapse was 180 days, and the median follow‐up from relapse to the last follow‐up was 1844 days. The 3‐year overall survival (OS) rate was 12.0%. The main cause of death was disease progression or subsequent relapse (82.6%). The majority of children received salvage treatment with curative intent without a second HSCT (67.8%), 22.0% of children underwent a second allo‐HSCT, and 10.2% received palliative therapy. Isolated extramedullary relapse (hazard ratio (HR): 0.607, P =.011) and relapse earlier than 365 days post‐transplantation (HR: 2.101, P <.001 for 0‐180 days; HR: 1.522, P =.041 for 181‐365 days) were found in multivariate analysis to be significant prognostic factors for outcome. The type of salvage therapy in chemosensitive relapse was identified as a significant prognostic factor for OS. Conclusion: A salvage approach with curative intent may be considered for patients with post‐transplant relapse, even if they relapse in the first year post‐transplantation. For sustainable remission, a second allo‐HSCT may be recommended for patients who achieve complete remission after reinduction treatment. [ABSTRACT FROM AUTHOR]