Cousin vs. Sibling Donors in Haplo-HSCT

This observational study aims to emulate a hypothetical pragmatic, multicenter, non-blinded clinical trial enrolling adult patients undergoing haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with grafts derived from either cousin or sibiling donors. The main research question is whether cousin donor-derived haplo-HSCT is associated with inferior clinical outcomes relative to sibling donor-derived haplo-HSCT. Study participants consist of adult patients diagnosed with hematological malignancies who underwent cousin or sibiling haplo-HSCT between 2017 and 2024, and all eligible recipients will receive regular follow-up assessments.