Acute kidney injury and risk factors in pediatric patients undergoing hematopoietic stem cell transplantation.

BACKGROUND: Acute kidney injury (AKI) is a common complication of hematopoietic stem cell transplantation (HSCT) with increased mortality and morbidity. Understanding the risk factors for AKI is essential. This study aimed to identify AKI incidence, risk factors, and prognosis in pediatric patients post-HSCT. METHODS: We conducted a retrospective case-control study of 278 patients who were divided into two groups: those with AKI and those without AKI (non-AKI). The groups were compared based on the characteristics and clinical symptoms of patients, as well as post-HSCT complications and the use of nephrotoxic drugs. Logistic regression analysis was employed to identify the risk factors for AKI. RESULTS: A total of 16.9% of patients had AKI, with 8.5% requiring kidney replacement therapy. Older age (OR 1.129, 95% CI 1.061-1.200, p < 0.001), sinusoidal obstruction syndrome (OR 2.562, 95% CI 1.216-5.398, p = 0.011), hemorrhagic cystitis (OR 2.703, 95% CI 1.178-6.199, p = 0.016), and nephrotoxic drugs, including calcineurin inhibitors, amikacin, and vancomycin (OR 17.250, 95% CI 2.329-127.742, p < 0.001), were identified as significant independent risk factors for AKI following HSCT. Mortality rate and mortality due to AKI were higher in stage 3 patients than those in stage 1 and 2 AKI (p = 0.019, p = 0.007, respectively). Chronic kidney disease developed in 1 patient (0.4%), who was in stage 1 AKI (2.1%). CONCLUSIONS: AKI poses a serious threat to children post-HSCT, leading to alarming rates of mortality and morbidity. To enhance outcomes and mitigate these risks, it is vital to identify AKI risk factors, adopt early preventive strategies, and closely monitor this patient group.

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.

The impact of pretreatment serum cobalamin and folate levels on complications and peripheral blood recovery during induction chemotherapy of leukemia: a cross-sectional study.

OBJECTIVES: We aimed to evaluate the impact of pretreatment folate and vitamin B12 deficiencies on the frequency of complications and peripheral blood recovery, in children with acute lymphoblastic leukemia (ALL). METHODS: Pre-induction serum folate and vitamin B12 levels of 88 newly diagnosed ALL patients were evaluated retrospectively. Folate < 3 ng/mL and vitamin B12 < 200 pg/mL were accepted as deficiency. Median hemoglobin, absolute neutrophil count (ANC), and platelet counts, transfusion needs, and complications such as mucositis, febrile neutropenia (FN), bleeding at diagnosis, at 15th and 33rd day of induction, were assessed. Recovery of peripheral blood count, which was defined as an ANC > 1.0 × 109/L and platelet count > 100 × 109/L at 33rd day of chemotherapy were also evaluated. RESULTS: Folate or vitamin B12 deficiencies were observed in 21 (23%) and 40 (45%) children, respectively. Peripheral blood counts, complications rates, and transfusion needs were not statistically different between deficient and normal level groups during induction. The number of febrile days, though not statistically significant, was higher in the both deficient groups. Seventeen of 40 (42.5%) patients with vitamin B12-deficient and 12 of 21 (57.1%) folate-deficient patients experienced at least one episode of FN during induction. FN was more common in folate-deficient group, but that was not statistically significant. Complete peripheral blood recovery at 33rd day of induction was seen in 40% in the vitamin B12-deficient group and 28.6% in folate-deficient group. Peripheral blood recovery rate at day 33 was also similar in both deficient and normal level groups. CONCLUSION: Although pre-induction low serum levels of vitamin B12 and folate did not have statistically significant impact on disease-/treatment-related complications and peripheral blood recovery at induction, the frequency of FN and number of febrile day were higher in both deficiencies and folate-deficient patients, respectively.

Abatacept as a Long-Term Targeted Therapy for LRBA Deficiency.

BACKGROUND: LPS-responsive beige-like anchor (LRBA) deficiency presents with susceptibility to infections, autoimmunity, and lymphoproliferation. The long-term efficacy of cytotoxic T-lymphocyte-associated antigen 4-immunoglobulin (abatacept) as targeted therapy for its immune dysregulatory features remains to be established. OBJECTIVE: To determine the clinical and immunologic features of LRBA deficiency and long-term efficacy of abatacept treatment in controlling the different disease manifestations. METHODS: Twenty-two LRBA-deficient patients were recruited from different immunology centers and followed prospectively. Eighteen patients on abatacept were evaluated every 3 months for long-term clinical and immunologic responses. LRBA expression, lymphocyte subpopulations, and circulating T follicular helper cells were determined by flow cytometry. RESULTS: The mean age of the patients was 13.4 ± 7.9 years, and the follow-up period was 3.4 ± 2.3 years. Recurrent infections (n = 19 [86.4%]), immune dysregulation (n = 18 [81.8%]), and lymphoproliferation (n = 16 [72.7%]) were common clinical features. The long-term benefits of abatacept in 16 patients were demonstrated by complete control of lymphoproliferation and chronic diarrhea followed by immune dysregulation, most notably autoimmune cytopenias. Weekly or every other week administration of abatacept gave better disease control compared with every 4 weeks. There were no serious side effects related to the abatacept therapy. Circulating T follicular helper cell frequencies were found to be a reliable biomarker of disease activity, which decreased on abatacept therapy in most subjects. However, high circulating T follicular helper cell frequencies persisted in 2 patients who had a more severe disease phenotype that was relatively resistant to abatacept therapy. CONCLUSIONS: Long-term abatacept therapy is effective in most patients with LRBA deficiency.

Clinical features and treatment of primary autoimmune hemolytic anemia in childhood.

BACKGROUND AND AIM: Autoimmune hemolytic anemia (AIHA) is characterized by autoimmune destruction of erythrocytes. In this retrospective study, the clinical, laboratory features and treatment responses of patients with primary AIHA were evaluated. MATERIAL AND METHODS: 21 consecutive patients diagnosed with primary AIHA in a children's hospital from 2008 to 2016 were included. Clinical, laboratory findings and treatment responses were analyzed. RESULTS: Twenty-one patients, aged 6 months-15 years, with direct antiglobulin test positive anemia were presented. Pallor and jaundice were the common complaints and icterus and hepatomegaly /splenomegaly was the most common physical findings. Thirteen patients (62%) had a previous infection history. At the time of diagnosis, hemoglobin level was 3-10.5 g/dL. Fifty- eight percent of patients had IgG reactivity and 29.4% patients had both IgG and C3d reactivity. Eight patients were given methylprednisolone, 11 patients received prednisone and 14 patients received intravenous immunoglobulin. Five patients (23.8%) were transfused due to severe anemia. Two patients did not need any treatment. The response rate following first-line treatment was 94%. One patient who did not respond any treatment died of infection. CONCLUSION: Primary AIHA is an acute illness mostly self-limiting or requiring short-term steroid therapy. Rarely, it might be resistant to immunosuppressive treatment and be mortal.