Hematopoietic stem cell transplantation in patients with severe combined immunodeficiency: A single-center experience

Objective: The aim of this study was to determine the factors affecting outcomes in patients who underwent hematopoietic stem cell transplantation (HSCT) with the diagnosis of severe combined immunodeficiency (SCID). Furthermore, our aim is to share our singlecenter experience of HSCT among SCID patients. Materials and Methods: The data of patients who underwent HSCT with the diagnosis of SCID between January 2014 and January 2021 in the pediatric bone marrow transplant unit of Istanbul Medipol University were retrospectively analyzed. Demographic and clinical data, treatment regimens, donor source, type of transplantation, pre- and post-transplantation infections, and complications were evaluated. Results: Among fifteen patients who underwent HSCT, 5 (33%) were female. The mean age at diagnosis was 3 months (1-6 months), and at transplantation 6 months (3-10 months). The mean time from diagnosis to transplantation was 3 months (2-9 months). There was a history of consanguineous marriage in thirteen (87%) and sibling death in eight (53%) cases. As donors, six (40%) were siblings and five (33%) were unrelated, while four (27%) patients underwent haploid transplantation. Four (27%) patients died during the first 100 days of transplantation. The median follow-up period was 23 months (9-61 months). Overall survival probability was calculated as 73%. Conclusion: SCID should be considered as an emergency in pediatrics. Devastating complications, including severe organ damage, lifethreatening infections, and even death, could appear in case of diagnostic delay. HSCT is a currently available curative treatment option. Subjects with a confirmed diagnosis should be referred to the appropriate bone marrow transplant center and treated as soon as possible.