Effect of HLA matching on survival after cord blood transplantation

Abstract

Object: Peripheral blood and bone marrow stem cells are frequently used for treatment of hematopoietic malignancies. The use of cord blood units has been increasing for hematopoietic stem cell transplantations (HSCTs). Human leukocyte antigens (HLA) matching is crucial for succesful transplant outcome. Provision of unrelated stem cells is more difficult for patients within minority groups. Besides HLA matching,availability of the donor for the procedure may also cause delays. HLA matching requirement between donor and patient is less crucial for cord blood transplantation presumably due to tolerance development during pregnancy.The number of unrelated HSCTs performed in Turkey has been increasing. The use of cord blood units has also increased significantly in the recent years. In this study, the main goal was to determine the effect of HLA matching on survival after cord blood transplantation. Material and Method: Between 2008 and 2014, cord blood unit search applications for 102 patients resulted in a transplantation through İstanbul University, Istanbul Medical Faculty, Bone Marrow Bank. Findings: It was on average 45 days between the search request and transplantation ( range:11-113 days).Average age of the patients is 4,3 ± 2,8 (1-30 years), male-to-female ratio was 64/38. The most frequent diseases resulting in transplantation were SCID (n=23), AML (n=13), osteopetrosis (n=10) and ALL (n=10).There were 39 (38 %) cord blood transplantations with matched HLA -A, -B, -DR; 54 (52%) mismatched for HLA-A or -B antigens; 9 (9%) mismatched for HLA-DR only and 1 (1%) mismatched for HLA-B and -DR antigens.The overall survival rate after HSCT with cord blood was 79.4% (n= 31/39).

The overall survival rate of the patients with Class-I antigens mismatch is 51.8% (26/54), the patients with Class-II antigens mismatch is 77,7% (2/9) after the HSCT.