Cousin vs. Sibling Donors in Haplo-HSCT

Comparison of Outcomes of Haploidentical Hematopoietic Stem Cell Transplantation From Cousin Donors Versus Sibling Donors in Patients With Hematological Malignancies: A Target Trial Emulation Study

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.

Inclusion Criteria:

• Adult patients diagnosed with hematological malignancies, including acute leukemia (AL), chronic myeloid leukemia (CML), myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), and non-Hodgkin lymphoma (NHL)
• Receipt of first haploidentical hematopoietic stem cell transplantation between 2017 and 2024
• Documented exact date of transplantation available in medical charts
• Verifiable donor kinship classified as either cousin or sibiling
• Complete longitudinal follow-up data accessible for outcome assessment

Exclusion Criteria:

• Prior receipt of any form of hematopoietic stem cell transplantation
• An age difference of more than 18 years between the donor and recipient
• Failure of successful infusion of donor-derived hematopoietic stem cells following conditioning regimen