Artemis deficiency: A large cohort including a novel variant with increased radiosensitivity.

BACKGROUND: Artemis deficiency is an autosomal recessive disorder characterized by a combined immunodeficiency with increased cellular radiosensitivity. In this review, the clinical and genetic characteristics of 15 patients with DCLRE1C variants are presented. METHODS: The demographic, clinical, immunologic, and genetic characteristics of patients with confirmed DCLRE1C variants diagnosed between 2013 and 2023 were collected retrospectively. Three patients were evaluated for radiosensitivity by the Comet assay, compared with age- and sex-matched healthy control. RESULTS: Seven patients who had severe infections in the first 6 months of life were diagnosed with T-B-NK+ SCID (severe combined immunodeficiency). Among them, four individuals underwent transplantation, and one of those died due to post-transplant complications in early life. Eight patients had hypomorphic variants. Half of them were awaiting a suitable donor, while the other half had already undergone transplantation. The majority of patients were born into a consanguineous family (93.3%). Most patients had recurrent sinopulmonary infections (73.3%), and one patient had no other infection than an acute respiratory infection before diagnosis. Two patients (13.3%) had autoimmunity in the form of autoimmune hemolytic anemia. Growth retardation was observed in only one patient (6.6%), and no malignancy was detected in the surviving 11 patients during the median (IQR) of 21.5 (12-45) months of follow-up. Three patients who had novel variants exhibited increased radiosensitivity and compromised DNA repair, providing a potential vulnerability to malignant transformation. CONCLUSION: Early diagnosis, radiation avoidance, and careful preparation for transplantation contribute to minimizing complications, enhancing life expectancy, and improving the patient's quality of life.

Comparison of tacrolimus vs. cyclosporine in pediatric hematopoietic stem cell transplantation for thalassemia.

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.

COVID-19 disease in children and adolescents following allogeneic hematopoietic stem cell transplantation: A report from the Turkish pediatric bone marrow transplantation study group.

BACKGROUND: Data on the risk factors and outcomes for pediatric patients with SARS-CoV-2 infection (COVID-19) following hematopoietic stem cell transplantation (HSCT) are limited. OBJECTIVES: The study aimed to analyze the clinical signs, risk factors, and outcomes for ICU admission and mortality in a large pediatric cohort who underwent allogeneic HSCT prior to COVID-19 infection. METHOD: In this nationwide study, we retrospectively reviewed the data of 184 pediatric HSCT recipients who had COVID-19 between March 2020 and August 2022. RESULTS: The median time from HSCT to COVID-19 infection was 209.0 days (IQR, 111.7-340.8; range, 0-3845 days). The most common clinical manifestation was fever (58.7%). While most patients (78.8%) had asymptomatic/mild disease, the disease severity was moderate in 9.2% and severe and critical in 4.4% and 7.6%, respectively. The overall mortality was 10.9% (n: 20). Deaths were attributable to COVID-19 in nine (4.9%) patients. Multivariate analysis revealed that lower respiratory tract disease (LRTD) (OR, 23.20, p: .001) and lymphopenia at diagnosis (OR, 5.21, p: .006) were risk factors for ICU admission and that HSCT from a mismatched donor (OR, 54.04, p: .028), multisystem inflammatory syndrome in children (MIS-C) (OR, 31.07, p: .003), and LRTD (OR, 10.11, p: .035) were associated with a higher risk for COVID-19-related mortality. CONCLUSION: While COVID-19 is mostly asymptomatic or mild in pediatric transplant recipients, it can cause ICU admission in those with LRTD or lymphopenia at diagnosis and may be more fatal in those who are transplanted from a mismatched donor and those who develop MIS-C or LRTD.

Pre-transplantation vitamin D deficiency increases acute graft-versus-host disease after hematopoietic stem cell transplantation in thalassemia major patients.

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.

Hematopoietic stem cell transplantation in serine/threonine kinase 4 (STK4) deficiency: Report of two cases and literature review.

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.

Clinical and Laboratory Factors Affecting the Prognosis of Severe Combined Immunodeficiency.

PURPOSE: Severe combined immunodeficiency (SCID) is one of the most severe forms of inborn errors of immunity characterized by absence or loss of function in T cells. The long-term outcomes of all forms of SCID have been evaluated in a limited number of studies. We aimed to evaluate the pre- and post-transplant manifestations of SCID patients and determine the factors affecting the survival of patients. METHODS: We included 54 SCID patients (classical SCID, Omenn syndrome, atypical SCID (AS)) in this study. We evaluated the clinical presentation, infections, and outcome of hematopoietic stem cell transplantation (HSCT). Lymphocyte subsets and T-cell receptor (TCR) repertoire were analyzed by flow cytometry. RESULTS: The median age at diagnosis was 5 (range: 3-24) months and follow-up time was 25 (range: 5-61) months. Symptom onset and diagnostic ages were significantly higher in AS compared to others (p = 0.001; p < 0.001). The most common SCID phenotype was T-B-NK + , and mutations in recombination-activating genes (RAG1/2) were the prominent genetic defect among patients. The overall survival (OS) rate was 83.3% after HSCT, higher than in non-transplanted patients (p = 0.001). Peripheral blood stem cell sources and genotypes other than RAG had a significant favorable impact on CD4+ T cells immune reconstitution after transplantation (p = 0.044, p = 0.035; respectively). Gender matching transplantations from human leukocyte antigen (HLA)-identical and non-identical donors and using peripheral blood stem cell source yielded higher B-cell reconstitution (p = 0.002, p = 0.028; respectively). Furthermore, receiving a conditioning regimen provided better B-cell reconstitution and chimerism (p = 0.003, p = 0.001). Post-transplant TCR diversity was sufficient in the patients and showed an equal distribution pattern as healthy controls. The OS rate was lower in patients who underwent transplant with active infection or received stem cells from mismatched donors (p = 0.030, p = 0.015; respectively). CONCLUSION: This study identifies diagnostic and therapeutic approaches predictive of favorable outcomes for patients with SCID.

Low Density Granulocytes and Dysregulated Neutrophils Driving Autoinflammatory Manifestations in NEMO Deficiency.

NF-κB essential modulator (NEMO, IKK-γ) deficiency is a rare combined immunodeficiency caused by mutations in the IKBKG gene. Conventionally, patients are afflicted with life threatening recurrent microbial infections. Paradoxically, the spectrum of clinical manifestations includes severe inflammatory disorders. The mechanisms leading to autoinflammation in NEMO deficiency are currently unknown. Herein, we sought to investigate the underlying mechanisms of clinical autoinflammatory manifestations in a 12-years old male NEMO deficiency (EDA-ID, OMIM #300,291) patient by comparing the immune profile of the patient before and after hematopoietic stem cell transplantation (HSCT). Response to NF-kB activators were measured by cytokine ELISA. Neutrophil and low-density granulocyte (LDG) populations were analyzed by flow cytometry. Peripheral blood mononuclear cells (PBMC) transcriptome before and after HSCT and transcriptome of sorted normal-density neutrophils and LDGs were determined using the NanoString nCounter gene expression panels. ISG15 expression and protein ISGylation was based on Immunoblotting. Consistent with the immune deficiency, PBMCs of the patient were unresponsive to toll-like and T cell receptor-activators. Paradoxically, LDGs comprised 35% of patient PBMCs and elevated expression of genes such as MMP9, LTF, and LCN2 in the granulocytic lineage, high levels of IP-10 in the patient's plasma, spontaneous ISG15 expression and protein ISGylation indicative of a spontaneous type I interferon (IFN) signature were observed, all of which normalized after HSCT. Collectively, our results suggest that type I IFN signature observed in the patient, dysregulated LDGs and spontaneously activated neutrophils, potentially contribute to tissue damage in NEMO deficiency.

Timing of Initiation of Calcineurin Inhibitors in Pediatric Haploidentical Transplantation with Post-Transplantation Cyclophosphamide: Effects on Survival, Relapse, and Cytokine Release Syndrome.

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.

Genomic Spectrum and Phenotypic Heterogeneity of Human IL-21 Receptor Deficiency.

Biallelic inactivating mutations in IL21R causes a combined immunodeficiency that is often complicated by cryptosporidium infections. While eight IL-21R-deficient patients have been reported previously, the natural course, immune characteristics of disease, and response to hematopoietic stem cell transplantation (HSCT) remain to be comprehensively examined. In our study, we have collected clinical histories of 13 patients with IL-21R deficiency from eight families across seven centers worldwide, including five novel patients identified by exome or NGS panel sequencing. Eight unique mutations in IL21R were identified in these patients, including two novel mutations. Median age at disease onset was 2.5 years (0.5-7 years). The main clinical manifestations were recurrent bacterial (84.6%), fungal (46.2%), and viral (38.5%) infections; cryptosporidiosis-associated cholangitis (46.2%); and asthma (23.1%). Inflammatory skin diseases (15.3%) and recurrent anaphylaxis (7.9%) constitute novel phenotypes of this combined immunodeficiency. Most patients exhibited hypogammaglobulinemia and reduced proportions of memory B cells, circulating T follicular helper cells, MAIT cells and terminally differentiated NK cells. However, IgE levels were elevated in 50% of IL-21R-deficient patients. Overall survival following HSCT (6 patients, mean follow-up 1.8 year) was 33.3%, with pre-existing organ damage constituting a negative prognostic factor. Mortality of non-transplanted patients (n = 7) was 57.1%. Our detailed analysis of the largest cohort of IL-21R-deficient patients to date provides in-depth clinical, immunological and immunophenotypic features of these patients, thereby establishing critical non-redundant functions of IL-21/IL-21R signaling in lymphocyte differentiation, humoral immunity and host defense against infection, and mechanisms of disease pathogenesis due to IL-21R deficiency. Outcome following HSCT depends on prior chronic infections and organ damage, which should thus be considered as early as possible following molecular diagnosis.

Analyzing the clinical outcomes of switching from cyclosporine to tacrolimus in pediatric hematopoietic stem cell transplantation.

OBJECTIVE: The selection of graft-vs. -host disease (GvHD) prophylaxis is vital for the success of hematopoetic stem cell transplantation (HSCT), and calcineurin inhibitors (CNI) have been used for decades as the backbone of GvHD prophylaxis. The aim of this study is to analyze the results of switching cyclosporine (CSA) to tacrolimus because of acute GvHD, engraftment syndrome (ES), persistent low level of CSA, or various CSA-associated adverse events in the first 100 days of pediatric HSCT. MATERIALS AND METHODS: This is a retrospective analysis of 192 patients who underwent allogeneic hematopoietic stem cell transplantation at Medicalpark Göztepe and Antalya Hospitals between April 2014 and May 2019 had therapy switched from CSA to tacrolimus-based immunosuppression within 100 days of transplant. RESULTS: The reasons for conversion to tacrolimus were low level of CSA (n = 70), aGvHD (n = 63), CSA-associated neurotoxicity (n = 15), CSA-associated nephrotoxicity (n = 10), hypertension (n = 10), allergic reactions (n = 9), ES (n = 7), CSA-associated hepatotoxicity (n = 5), and vomiting (n = 3). The median day after transplant for conversion to tacrolimus for all patients was day 20 (range 0-100 days). Response rates to conversion were 38% for GvHD, 86% for neurotoxicity, 50% for nephrotoxicity, 60% for hepatotoxicity, 80% for hypertension, 66% for vomiting, and 57% for ES. Twenty-nine patients (15%) experienced tacrolimus-associated toxicities after therapy conversion to tacrolimus. Neurotoxicity emerged as posterior reversible encephalopathy syndrome (PRES), which was the most common toxicity observed after conversion (18/29 patients). CONCLUSION: Our data support the quick conversion to tacrolimus in the condition of persistent low CSA levels with acceptable efficacy and safety. Although both drugs are CNI and share a very similar mechanism of action, the conversion could be preferred especially in specific organ toxicities with special attention for neurotoxicity after conversion.

Allogeneic hematopoietic stem cell transplantation in patients with childhood cerebral adrenoleukodystrophy: A single-center experience "Better prognosis in earlier stage".

BACKGROUND: ALD is a rare X-linked peroxisomal metabolic disorder with many distinct phenotypes of disease that emerge on a wide scale from adrenal insufficiency to fatal cALD which progresses to a vegetative state within a few years. Currently, HSCT is the only treatment method known to stabilize disease progression in patients with cALD. In this study, we aim to report our HSCT experience in patients with cALD and the factors that determine the success of HSCT, as a single-center experience. METHODS: The study cohort involves 23 boys with cALD and three patients with ALD trait and new-onset abnormal behavior who underwent allogeneic HSCT between January 2012 and September 2019 in our transplantation center. Loes scoring, NFS, scale and MFD were performed for evaluating the severity of the cerebral disease. The study cohort was divided into two groups according to baseline NFS and Loes score: early-stage (NFS ≤ 1 and Loes score <9) and advanced stage (NFS > 1 or Loes score ≥9). RESULTS: The pretransplant stage of disease impacted both OS and MFD-free survival. The estimated OS and MFD-free survival at 3 years in patients with advanced disease were 46.1% (95% CI 19.0-73.2) and 23.1% (95% CI 0.2-46.0), respectively, and all patients with the early disease were alive (p: .004) and MFD-free (p < .001) at 3 years. CONCLUSION: This study demonstrated that early HSCT is vital in patients with cALD. The early-stage disease had a significant survival advantage and free from disease progression after HSCT.

Prognostic factors for survival in children who relapsed after allogeneic hematopoietic stem cell transplantation for acute leukemia.

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.

Comparison of Total Body Irradiation-based Versus Chemotherapy-based Conditionings for Early Complications of Allogeneic Hematopoietic Stem Cell Transplantation in Children With ALL.

BACKGROUND: Total body irradiation (TBI) is the cornerstone of conditioning regimens in pediatric hematopoietic stem cell transplantation for acute lymphoblastic leukemia. As the late effects and survival comparison between TBI and chemotherapy were well analyzed before, in this study, we aim to focus on the first 100 days and early complications of transplantation. METHODS: This retrospective study involves 72 pediatric patients (0 to 18 y) underwent first hematopoietic stem cell transplantation for acute lymphoblastic leukemia between October 2015 and May 2019. Patients are divided into 2 groups regarding conditioning regimens. Conditionings includes either TBI 1200 cGy/6 fractions/3 days and etoposide phosphate or busulfan, fludarabine, and thiotepa. Busulfan was administered IV and according to body weight. RESULTS: The incidences of acute graft versus host disease grade 2 to 4, veno-occlusive disease, capillary leakage syndrome, thrombotic microangiopathy, blood stream infection, hemorrhagic cystitis and posterior reversible encephalopathy syndrome before day 100 were similar for both conditioning regimens; however, patients received TBI-based conditioning had significantly longer neutrophil engraftment time (17.5 vs. 13 d, P=0.001) and tended to have more engraftment syndrome (ES) (45.5% for TBI vs. 24.0% for chemotherapy, P=0.069). Multivariate analysis showed that TBI-based conditioning was associated with a longer neutrophil engraftment time (hazard ratio [HR]=1.20, P=0.006), more cytomegalovirus (CMV) reactivation (HR=3.65, P=0.038) and more ES (HR=3.18, P=0.078). CONCLUSIONS: Our findings support chemotherapy-based regimens with early neutrophil engraftment, less ES and CMV reactivation compared with TBI. Although there is no impact on survival rates, increased incidence of ES and CMV reactivation should be considered in TBI-based regimens.

ILC3 deficiency and generalized ILC abnormalities in DOCK8-deficient patients.

BACKGROUND: Dedicator 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. METHODS: Peripheral 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. RESULTS: DOCK8-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. CONCLUSION: DOCK8 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.

Ruxolitinib salvage therapy is effective for steroid-refractory graft-versus-host disease in children: A single-center experience.

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.

Use of low cell dose for unmanipulated donor lymphocyte for management of cytomegalovirus infection: A single-center experience.

Although advancements have been made in monitoring and preventing viral infections in HSCT patients, CMV reactivation still remains a critical post-transplant complication. Adoptive cell therapy is an alternative to pharmacotherapy of CMV infection in refractory patients. We retrospectively reviewed CMV infection cases after allogeneic HSCT who received U-DLI as treatment. In total, five pediatric patients between the ages of 0.5-16 years that received U-DLI for a post-HSCT CMV infection were evaluated. The dose of CD3+ lymphocytes administered in DLI was 5 × 104 /kg, except in one patient transplanted from his sibling. One patient, who was transplanted from an unrelated donor, received U-DLI from his haploidentical mother. CMV titers dramatically reduced after U-DLI. If the availability of CMV-specific CTL is an issue, we propose that one should consider using the U-DLI therapy with low cell dose from a seropositive donor. In case the stem cell donor is seronegative and a seropositive donor is unavailable, using the U-DLI therapy from seropositive, haploidentical donors is a promising way of treatment. More studies need to be conducted to further confirm the safety and efficacy of this treatment procedure.

Hematopoietic stem cell transplantation in CD40 ligand deficiency: A single-center experience.

Deficiency of the CD40L, expressed on the surface of T lymphocytes, is caused by mutations in the glycoprotein CD40L (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 Göztepe 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.

Hematopoietic Stem Cell Transplantation in Congenital Dyserythropetic Anemia Type II: A Case Report and Review of the Literature.

Currently, there is no guideline for the treatment of patients with congenital dyserythropoietic anemia (CDA) type II. One approach is to follow-up patients with transfusions, on the basis of individually determined target hemoglobin levels, and iron chelation according to the thalassemia guidelines. In some transfusion-dependent CDA II patients, splenectomy reduces the number of transfusions; however, the only known curative option for CDA II patients is hematopoietic stem cell transplantation (HSCT). Only a few published case reports of allogeneic HSCT in CDA II patients are available. Here, we review the literature and add our data of a CDA II patient who developed transfusion dependence and was cured with HSCT.

Heterozygous activating mutation in RAC2 causes infantile-onset combined immunodeficiency with susceptibility to viral infections.

Here we describe a 10-year-old girl with combined immunodeficiency presenting as recurring chest infections, lung disease and herpetic skin infections. The patient experienced two hematopoietic stem cell transplantations and despite full chimerism, she developed bone marrow aplasia due to adenovirus infection and died at post-transplant day 86. Immunologic investigation revealed low numbers of TRECs/KRECs, a severe reduction of memory B cells, absence of isohemagglutinins, and low IgG levels. Whole exome sequencing (WES) identified a novel heterozygous mutation in RAC2(c.275A > C, p.N92 T). Flow cytometric investigation of neutrophil migration demonstrated an absence of chemotaxis to fMLP. Cell lines transfected with RAC2 [N92 T] displayed characteristics of active GTP-bound RAC2 including enhanced NADPH oxidase-derived superoxide production both at rest and in response to PMA. Our findings broaden the clinical picture of RAC2 dysfunction, showing that some individuals can present with a combined immunodeficiency later in childhood rather than a congenital neutrophil disease.

Deferasirox in children with transfusion-dependent thalassemia or sickle cell anemia: A large cohort real-life experience from Turkey (REACH-THEM).

OBJECTIVES: To evaluate the long-term efficacy and safety of deferasirox therapy in a large observational cohort of children with transfusion-dependent thalassemia (TDT) and sickle cell anemia (SCA) in Turkey. METHODS: This was a multicenter, prospective cohort study including TDT and SCA patients aged 2-18 years with iron overload (≥100 mL/kg of pRBC or a serum ferritin [SF] level >1000 µg/L) receiving deferasirox. Patients were followed for up to 3 years according to standard practice. RESULTS: A total of 439 patients were evaluated (415 [94.5%] TDT, 143 [32.6%] between 2 and 6 years). Serum ferritin levels consistently and significantly decreased across 3 years of deferasirox therapy from a median of 1775.5 to 1250.5 µg/L (P < 0.001). Serum ferritin decreases were noted in TDT (1804.9 to 1241 µg/L), SCA (1655.5 to 1260 µg/L), and across age groups of 2-6 years (1971.5 to 1499 µg/L), 7-12 years (1688.5 to 1159.8 µg/L), and 13-18 years (1496.5 to 1107 µg/L). Serum ferritin decreases were also noted for all deferasirox dose groups but only significant in patients with doses ≥30 mg/kg/d (n = 120, -579.6 median reduction, P < 0.001). Only 9 (2%) patients had adverse events suspected to be related to deferasirox. Serum creatinine slightly increased but remained within the normal range. CONCLUSIONS: Deferasirox has long-term efficacy and safety in children with TDT and SCA, although higher doses (≥30 mg/kg/d) may be required to achieve iron balance.