Central line-associated bloodstream infection outbreak related to Ralstonia pickettii-contaminated saline in a pediatric hematopoietic stem cell transplant center.

BACKGROUND: Ralstonia pickettii is an aerobic Gram-negative non-fermentative bacillus. It is an opportunistic pathogen that has recently prompted nosocomial outbreaks. Although it has low virulence, it can cause a wide range of invasive diseases in immunosuppressive patients. The characteristics of R. pickettii-related central line-associated bloodstream infection (CLABSI) outbreak in pediatric hematopoietic stem cell transplant (HSCT) recipients are presented in this study. MATERIALS AND METHODS: This was a single-center, retrospective analysis conducted at Bahcesehir University Goztepe Medicalpark Hospital . The clinical and laboratory characteristics of twelve children with Ralstonia-related CLABSIs were analyzed. RESULTS: Of the twelve patients with R. pickettii growth, seven were female. The median age was 12.1 (2-17) years. Autologous HSCT was performed in two of the patients and allogeneic HSCT was performed in ten patients for both malignant and non-malignant diseases. In the conditioning regimens, all patients were given myeloablative therapy. Clinical sepsis was the most common presentation. As a result of the investigations, R. pickettii growth was observed in saline solutions. All cases were successfully treated with the appropriate antibiotic regimen and the bacteria was not found in repeat cultures. Catheter removal was required in two patients. Mortality was not observed in any patient as the outcome of the infection episode. CONCLUSION: The detection and control of the infectious source are critical in pediatric HSCT patients with severe immunosuppression, as medical equipment-related outbreaks can be life-threatening.

Hematopoietic stem cell transplantation in children with mucopolysaccharidosis IVA: single center experience.

Mucopolysaccharidosis IVA (MPS IVA; Morquio syndrome) is a lysosomal storage disorder and features systemic skeletal dysplasia that is caused by defective Nacetylgalactosamine-6-sulfate sulfatase (GALNS). Although there are convincing data for hematopoietic stem cell transplantation (HSCT) in certain types of MPS, the studies are limited for MPS IVA and more data is still pending to show the efficacy/safety of HSCT. This study included 3 girls and 7 boys, with a median age of 75,5 months (35-186 months), who underwent allogeneic HSCT for severe MPS IVA between February 12, 2021, and March 10, 2023. Enzyme levels, height growth, the most involved organs (ear, eye, and heart), and the activities of daily living (ADL) scoring system were monitored to assess the benefit of HSCT. In a median follow-up of 20 months (9-34 months), there is no severe transplant-related adverse event was observed. In all cases, normal enzyme levels were reached after HSCT. During the short follow-up period, our cases showed an increase in stature and improvement in daily activity functions. Here we present the data of our HSCT experience in MPS IVA with promising results regarding both safety and efficacy. Although there are signs of amelioration with HSCT, we need more data and long-term follow-up to comment properly on the benefits of HSCT in MPS IVA.

Successful Treatment of Severe Aplastic Anemia with Hematopoietic Stem Cell Transplantation in the Setting of Active Mucormycosis.

Severe aplastic anemia (SAA) is a life-threatening hematological disease characterized by the suppression of the bone marrow. Patients with SAA are predisposed to recurrent bacterial infections and invasive fungal infections (IFI) due to profound and persistent neutropenia. Mucorales are the second most common cause of IFI encountered in SAA. Here we present a pediatric case of SAA with active mucormycosis infection of the paranasal sinuses. In the first step, surgical debridement was performed and combined antifungal therapy (liposomal amphotericin B, posaconazole, caspofungin) was started. Due to severe neutropenia, daily granulocyte transfusion was added to therapy. Hyperbaric oxygen therapy was applied for wound healing. After all this the patient went under flap surgery. One week after the successful flap procedure, HSCT was performed and he had no complications related to HSCT. The patient was followed in the outpatient clinic for 6 months with posaconazole. Now, he is out of drugs and followed without problems for 15 months after HSCT. Our case confirms that urgent HSCT with multiple therapies (surgical debridement, granulocyte support, combined antifungal therapy, hyperbaric O2) is crucial for saving life in SAA patients with active mucormycosis.

MHC Class II Deficiency: Clinical, Immunological, and Genetic Insights in a Large Multicenter Cohort.

BACKGROUND: Major histocompatibility complex class II deficiency, a combined immunodeficiency, results from loss of HLA class II expression on antigen-presenting cells. Currently, hematopoietic stem cell transplantation stands as the sole curative approach, although factors influencing patient outcomes remain insufficiently explored. OBJECTIVES: To elucidate the clinical, immunologic, and genetic profiles associated with MHC-II deficiency and identify prognostic indicators that affect survival rates. METHODS: In this multicenter retrospective analysis, we gathered data from 35 patients with a diagnosis of MHC-II deficiency across 12 centers in Turkey. We recorded infection histories, gene mutations, immune cell subsets, and surface MHC-II expression on blood cells. We conducted survival analyses to evaluate the impact of various factors on patient outcomes. RESULTS: Predominant symptoms observed were pneumonia (n = 29; 82.9%), persistent diarrhea (n = 26; 74.3%), and severe infections (n = 26; 74.3%). The RFXANK gene mutation (n = 9) was the most frequent, followed by mutations in RFX5 (n = 8), CIITA (n = 4), and RFXAP (n = 2) genes. Patients with RFXANK mutations presented with later onset and diagnosis compared with those with RFX5 mutations (P =.0008 and .0006, respectively), alongside a more significant diagnostic delay (P = .020). A notable founder effect was observed in five patients with a specific RFX5 mutation (c.616G>C). The overall survival rate for patients was 28.6% (n = 10), showing a significantly higher proportion in individuals with hematopoietic stem cell transplantation (n = 8; 80%). Early death and higher CD8+ T-cell counts were observed in patients with the RFX5 mutations compared with RFXANK-mutant patients (P = .006 and .009, respectively). CONCLUSIONS: This study delineates the genetic and clinical panorama of MHC-II deficiency, emphasizing the prevalence of specific gene mutations such as RFXANK and RFX5. These insights facilitate early diagnosis and prognosis refinement, significantly contributing to the management of MHC-II deficiency.

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.

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.

Combined Haploidentical Hematopoetic Stem Cell Transplantation and Liver Transplantation in a Pediatric Patient.

Solid organ transplantation from the same donor is an established procedure for end-stage organ failure that developed after a previous hematopoietic stem cell transplantation (HSCT); however, it is rarely done in patients transplanted with unmanipulated haplo-HSCT. There are no pediatric reports regarding the long-term performance of organ transplantation after haplo-HSCT with post-transplant cyclophosphamide (PTCY). A juvenile myelomonocytic leukemia patient, who underwent unmanipulated haplo-HSCT with PTCY from her mother at the age of 3 years, developed chronic liver graft versus host disease (GvHD) which was refractory to specific GvHD treatment. Liver transplantation (LT) from her mother (the donor of her haplo-HSCT) was decided as the next line of treatment. LT was performed on day 540 post-HSCT, and the donor's left lateral segment was appropriately removed and attached to the recipient. The symptoms of GvHD completely regressed in a month. The patient died on day 121 after LT, because of a possible hepato-pulmonary syndrome. Organ failure can develop after allo-HSCT secondary to GvHD and therefore performing HSCT from a haplo-donor may be superior to a matched unrelated donor in terms of subsequent organ transplantation for organ failure.

[Investigation of Ganciclovir Resistance in Cytomegalovirus Isolates by Phenotypic and Genotypic Methods]. / Sitomegalovirüs Izolatlarinda Gansiklovir Direncinin Fenotipik ve Genotipik Yöntemlerle Arastirilmasi.

Ganciclovir-resistant cytomegalovirus (CMV) strains are reported following long-term antiviral agent use, especially for immune-suppressive patients. In this study, it was aimed to investigate the mutations in the UL97 gene of CMV, which causes ganciclovir (GCV) resistance by genotypic and phenotypic methods in patients who developed CMV infection following hematopoietic cell (HCT) or solid organ transplantation (SOT). Thirty patients who had HCT or SOT in Mediterranean University Hospital and developed CMV infection during routine follow-up with a viral load of CMV over 1000 copies/mL were included in the study. CMV DNA was analyzed by an automated system (Cobas Ampliprep/COBAS TaqMan CMV Test, Roche Diagnostics, Germany) quantitatively. DNA sequence analysis of the regions including codons 420-664 in the UL97 gene region was done by the Sanger sequencing method to detect mutations causing antiviral resistance and compared with defined mutations. In order to investigate antiviral resistance by phenotypic methods, heparinized blood samples of the patients were collected, 'buffy coat (leukocyte layer)' was inoculated into MRC-5 cells by centrifugation method and CMV growth in these cells was controlled with monoclonal antibodies when growth was detected, virus titer was determined and plaque reduction test was applied as recommended. It was determined that 22 of the 30 patients were HCT recipients and eight were SOT (five kidney, three liver) recipients. When the CMV serology pattern of the patients was evaluated before transplantation, 29 (96.7%) patients were found to be seropositive and one (3.3%) patient was found to be seronegative. Totally, nine CMV UL97 mutations were detected in seven (23.3%) pediatric patients who had HCT, including six seropositive and one seronegative case. In addition, one mutation (D605E) not known to cause GCV resistance was detected in a seronegative recipient and three previously unidentified mutations were detected (1474T, F499S, V559A) in a seronegative recipient. Five of the mutations defined were UL97 mutations with a defined clinical resistance against GCV in each of the five recipients (C603W, C592G, H520Q, M460V, A594T). In the plaque reduction test using 3 µM, 12 µM, 48 µM and 96 µM concentrations of GCV in CMV strains, the IC50 value was determined to be ≥ 8 µM for the five CMV strains, and the phenotypic presence of GCV resistance was shown. Clinical resistance associated with CMV UL97 mutation was detected in five (22.7%) of 22 patients who had HCT. GCV resistance was also demonstrated in these patients by phenotypic methods. No UL97 mutation was detected in the patients who had SOT.

In Vitro FVIII-Encoding Transgenic Mesenchymal Stem Cells Maintain Successful Coagulation in FVIII-Deficient Plasma Mimicking Hemophilia A

Objective: Hemophilia A is an X-linked recessive bleeding disorder caused by a deficiency of plasma coagulation factor VIII (FVIII), and it accounts for about 80%-85% of all cases of hemophilia. Plasma-derived therapies or recombinant FVIII concentrates are used to prevent and treat the bleeding symptoms along with FVIII-mimicking antibodies. Recently, the European Medicines Agency granted conditional marketing approval for the first gene therapy for hemophilia A. The aim of this study was to determine the effectiveness of coagulation in correcting FVIII deficiency with FVIII-secreting transgenic mesenchymal stem cells (MSCs). Materials and Methods: A lentiviral vector encoding a B domain-deleted FVIII cDNA sequence with CD45R0 truncated (CD45R0t) surface marker was designed to develop a transgenic FVIII-expressing primary cell line by transducing MSCs. The efficacy and functionality of the FVIII secreted from the MSCs was assessed with anti-FVIII ELISA, CD45R0t flow cytometry, FVIII western blot, and mixing test analysis in vitro. Results: The findings of this study showed that the transgenic MSCs maintained persistent FVIII secretion. There was no significant difference in FVIII secretion over time, suggesting stable FVIII expression from the MSCs. The functionality of the FVIII protein secreted in the MSC supernatant was demonstrated by applying a mixing test in coagulation analysis. In the mixing test analysis, FVIII-deficient human plasma products were mixed with either a saline control or FVIII-secreted MSC supernatant. The mean FVIII level of the saline control group was 0.41±0.03 IU/dL, whereas the mean level was 25.41±33.38 IU/dL in the FVIII-secreting MSC supernatant mixed group (p<0.01). The mean activated partial thromboplastin time (aPTT) of the saline control group was 92.69±11.38 s, while in the FVIII-secreting MSC supernatant mixed group, the mean aPTT level decreased to 38.60±13.38 s (p<0.001). Conclusion: The findings of this in vitro study suggest that the new method presented here is promising as a possible treatment for hemophilia A. Accordingly, a study of FVIII-secreting transgenic MSCs will next be initiated in a FVIII-knockout animal model.

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.

The serial changes in myocardial functions after paediatric haematopoietic stem cell transplantation.

The aim of this study is to evaluate the changes in myocardial functions in children who underwent haematopoietic stem cell transplantation along with associated chemotherapy. Additionally, we evaluated the effect of baseline echocardiographic parameters on mortality. We evaluated 39 patients (mean age 7.4 years) who underwent haematopoietic stem cell transplantation owing to non-malignant disease. The control group included 39 healthy children who had normal cardiac findings. The myocardial functions were evaluated in all subjects by conventional echocardiography and tissue Doppler echocardiography before haematopoietic stem cell transplantation and in the 1st, 3rd, 6th, and 12th month after haematopoietic stem cell transplantation. All patients had normal left ventricular ejection fraction before haematopoietic stem cell transplantation, except one case. Before haematopoietic stem cell transplantation, the patient group had significantly greater mean pulmonary artery pressure and lower tricuspid valve annular plane excursion rate. Baseline E' velocities for mitral lateral annuli, septum, and tricuspid lateral annuli were lower in the patient group than the control group. The E' velocities for the left ventricle decreased in the patient group after haematopoietic stem cell transplantation, and then returned to baseline levels at the 6 months. E' and S' velocities for tricuspid lateral annuli also decreased after haematopoietic stem cell transplantation and were still depressed in the first year after haematopoietic stem cell transplantation. Baseline E' velocity for septum was significantly lower in patients who died after haematopoietic stem cell transplantation than patients who survived (p = 0.009). Subclinical impairment in both ventricular functions was observed after haematopoietic stem cell transplantation and the right ventricular functions were affected for longer periods than left ventricle after haematopoietic stem cell transplantation. The myocardial functions should be monitored after the first year of haematopoietic stem cell transplantation.

Preliminary Report of the Academic CAR-T (ISIKOK-19) Cell Clinical Trial in Turkey: Characterization of Product and Outcomes of Clinical Application

Objective: Chimeric antigen receptor T (CAR-T) cell therapies have already made an impact on the treatment of B-cell malignancies. Although CAR-T cell therapies are promising, there are concerns about commercial products regarding their affordability and sustainability. In this preliminary study, the results of the first production and clinical data of an academic CAR-T cell (ISIKOK-19) trial in Turkey are presented. Materials and Methods: A pilot clinical trial (NCT04206943) designed to assess the safety and feasibility of ISIKOK-19 T-cell therapy for patients with relapsed and refractory CD19+ tumors was conducted and participating patients received ISIKOK-19 infusions between October 2019 and July 2021. The production data of the first 8 patients and the clinical outcome of 7 patients who received ISIKOK-19 cell infusions are presented in this study. Results: Nine patients were enrolled in the trial [5 with acute lymphoblastic leukemia (ALL) and 4 with non-Hodgkin lymphoma (NHL)], but only 7 patients could receive treatment. Two of the 3 participating ALL patients and 3 of the 4 NHL patients had complete/partial response (overall response rate: 72%). Four patients (57%) had CAR-T-related toxicities (cytokine release syndrome, CAR-T-related encephalopathy syndrome, and pancytopenia). Two patients were unresponsive and had progressive disease following CAR-T therapy. Two patients with partial response had progressive disease during follow-up. Conclusion: Production efficacy and fulfillment of the criteria of quality control were satisfactory for academic production. Response rates and toxicity profiles were also acceptable for this heavily pretreated/refractory patient group. ISIKOK-19 cells appear to be a safe, economical, and efficient treatment option for CD19+ tumors. However, the findings of this study need to be supported by the currently ongoing ISIKOK-19 clinical trial.

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.

Thalassemia-free and graft-versus-host-free survival: outcomes of hematopoietic stem cell transplantation for thalassemia major, Turkish experience.

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.

Epstein-Barr virus-related lymphoproliferative disorders in T-cell repleted haploidentical transplantation with post-transplant cyclophosphamide.

EBV-associated lymphoproliferative disorders (LPDs) are common in hematopoietic stem cell transplantation (HSCT) with T-cell-depleted grafts, but are extremely rare in HSCT patients with T-cell-replete grafts with post-transplant cyclophosphamide (PTCy). Here we present the cases of two pediatric patients who developed EBV-related LPD after T-cell-replete haplo-HSCT with PTCy. One of these is the first reported case of EBV-positive mucocutaneous ulcer (EBVMCU) developing after PTCy. EBV-related diseases are rare in T-cell-replete haplo-HSCT patients with PTCy. However, in patients with risk factors, it is reasonable to screen for EBV viremia for LPD.

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.

Adverse COVID-19 outcomes in immune deficiencies: Inequality exists between subclasses.

BACKGROUND: Genetic deficiencies of immune system, referred to as inborn errors of immunity (IEI), serve as a valuable model to study human immune responses. In a multicenter prospective cohort, we evaluated the outcome of SARS-CoV-2 infection among IEI subjects and analyzed genetic and immune characteristics that determine adverse COVID-19 outcomes. METHODS: We studied 34 IEI patients (19M/15F, 12 [min: 0.6-max: 43] years) from six centers. We diagnosed COVID-19 infection by finding a positive SARS-CoV-2 PCR test (n = 25) and/or a lung tomography scoring (CORADS) ≥4 (n = 9). We recorded clinical and laboratory findings prospectively, fitted survival curves, and calculated fatality rates for the entire group and each IEI subclass. RESULTS: Nineteen patients had combined immune deficiency (CID), six with predominantly antibody deficiency (PAD), six immune dysregulation (ID), two innate immune defects, and one in the autoinflammatory class. Overall, 23.5% of cases died, with disproportionate fatality rates among different IEI categories. PAD group had a relatively favorable outcome at any age, but CIDs and IDs were particularly vulnerable. At admission, presence of dyspnea was an independent risk for COVID-related death (OR: 2.630, 95% CI; 1.198-5.776, p < .001). Concerning predictive roles of laboratory markers at admission, deceased subjects compared to survived had significantly higher CRP, procalcitonin, Troponin-T, ferritin, and total-lung-score (p = .020, p = .003, p = .014, p = .013, p = .020; respectively), and lower absolute lymphocyte count, albumin, and trough IgG (p = .012, p = .022, p = .011; respectively). CONCLUSION: Our data disclose a highly vulnerable IEI subgroup particularly disadvantaged for COVID-19 despite their youth. Future studies should address this vulnerability and consider giving priority to these subjects in SARS-Cov-2 therapy trials.