Anti-human leukocyte antigen-DPB1 antibody-associated transfusion-related acute lung injury after hematopoietic stem cell infusion.

Although relatively rare among transfusion reactions, transfusion-related acute lung injury (TRALI) is a life-threatening condition, making its prevention, recognition, and early intervention extremely important. Although many etiological factors have been identified, the most common reasons are anti-human leukocyte antigen (anti-HLA) and anti-human neutrophil antigen antibodies that pass from the donor to the recipient during transfusion. TRALI was shown with transfusion of all kinds of blood products, however, it is rarely seen after stem cell infusion. Despite an adult case who developed TRALI after stem cell infusion, there is no pediatric case of TRALI associated with hematopoietic stem cell infusion in the previous literature. Here, we report a pediatric case with TRALI after infusion of the hematopoietic stem cell product from his female donor who has recently given birth 6 months ago. A 9-year-old patient with acquired aplastic anemia was admitted for hematopoietic stem cell transplantation (HSCT) from an ABO and 10/10 HLA compatible 21-year-old sister donor the unmanipulated stem cell product was planned to be infused in 4 h. At the last hour of infusion, the patient had acute hypoxemia, tachycardia, and bilateral pulmonary edema. He was diagnosed with TRALI and completely recovered with supportive therapy in 48 h. The anti-HLA antibody analysis of the donor showed positivity of anti-HLA-DPB1 antibodies. We wanted to emphasize the need for examination of anti-HLA antibodies of the donor and plasma depletion of the product to avoid TRALI in HSCTs from multiparous female donors.

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.

A large single-center cohort of bare lymphocyte syndrome: Immunological and genetic features in Turkey.

Major histocompatibility complex class II (MHC-II) deficiency or bare lymphocyte syndrome (BLS) is a rare, early-onset, autosomal recessive, and life-threatening inborn error of immunity. We aimed to assess the demographic, clinical, laboratory, follow-up, and treatment characteristics of patients with MHC-II deficiency, together with their survival. We retrospectively investigated 21 patients with MHC-II deficiency. Female/male ratio was 1.63. The median age at diagnosis was 16.3 months (5 months-9.7 years). Nineteen patients (90.5%) had parental consanguinity. Pulmonary diseases (pneumonia, chronic lung disease) (81%), diarrhoea (47.6%), and candidiasis (28.6%) were common. Four (19%) had autoimmunity, two developed septic arthritis, and three (14%) developed bronchiectasis in the follow-up. Three patients (14%) had CMV viraemia, one with bilateral CMV retinitis. Eight (38.1%) had lymphocytopenia, and four (19%) had neutropenia. Serum IgM, IgA, and IgG levels were low in 18 (85.7%), 15 (71.4%), and 11 (52.4%) patients, respectively. CD4+ lymphocytopenia, a reversed CD4+/CD8+ ratio, and absent/low HLA-DR expressions were detected in 93.3%, 86.7%, and 100% of the patients, respectively. Haematopoietic stem cell transplantation (HSCT) was performed on nine patients, and four died of septicaemia and ARDS after HSCT. The present median age of patients survived is 14 years (1-31 years). Genetic analysis was performed in 10 patients. RFX5 homozygous gene defect was found in three patients (P1, P4 and P8), and RFXANK (P2 and P14) and RFXAP (P18 and P19) heterozygous gene defects were found in each two patients, respectively. This large cohort showed that BLS patients have severe combined immunodeficiency (SCID)-like clinical findings. Flow cytometric MHC-II expression study is crucial for the diagnosis, differential diagnosis with SCID, early haematopoietic stem cell transplantation (HSCT), and post-HSCT follow-up. Genetic studies are required first for matched family donor evaluation before HSCT and then for genetic counselling.