Haploidentical Stem Cell Transplant with Post-Transplant Cyclophosphamide in Pediatric Hemophagocytic Lymphohistiocytosis.

PURPOSE Primary hemophagocytic lymphohistiocytosis is a severe and uncommon disease affecting pediatric patients. Genetic abnormalities have been related to altered apoptosis and exaggerated inflammatory reactions. Chemoimmunotherapy and stem cell transplantation are treatment options, but transplant is the only curative treatment. Here we aim to describe the treatment with hematopoietic stem cell transplantation with a novel strategy and the outcomes. METHODS An observational, descriptive, case series study was performed in pediatric patients of two high complexity medical centers in Colombia. Data was collected retrospectively between 2015 and 2020. RESULTS We describe five pediatric cases with a diagnosis of primary hemophagocytic lymphohistiocytosis. All were treated with replete-cell haploidentical hematopoietic stem transplantation, reduced-intensity conditioning, and post-transplant cyclophosphamide, in two high-complexity centers in Colombia. All patients are alive, and one is receiving management for chronic graft-versus-host disease. CONCLUSION To the best of our knowledge, there are few reports in the literature with this strategy, promising a possible alternative when there are no other donor options.