#64
PROBABILITY OF FINDING HLA MATCHED UNRELATED MARROW DONORS FROM THE MEXICAN BONE MARROW REGISTRY-DONORMO FOR MEXICAN PATIENTS.
M. Loyola, MD, H. Flores, MC, C. Alaez, MC, M. Cruz, CP and C. Gorodezky, PhD. Mexico City Mexico, InDRE., 11340, Mexican Bone Marrow Donor Registry DONORMO. Dept. of Immunol.
Immunogenetics.
DONORMO was established to facilitate donor search and marrow procurement for patients lacking an identical sibling. HLA frequencies of transplant populations reflect the ethnicity of patients/donors. DNA typing has facilitated better donor selection. This study analyzed the possibility of finding a match among 3947 donors. We selected 883 Mexican patients typed for bone marrow transplantation. We searched potential donors retrospectively looking for full A-B-DR and one or more mismatches typed by DNA low-intermediate resolution. We found 95 fully matched donor-patient pairs (10.8%); one mismatch donors for 448 patients (50.7%) and 340 patients (38.5%) had no match. The most frequent alleles (AF%) in patients were: A*02 (40), A*24 (21.6), A*68 (10), A*31 (5.8), A*33 (5.3): B*35 (30), B*39 (24.7), B*4002 (7.9), B*14 (6.5) (6.3), B*44 (6.3), B*48 (4.2); DRB1*0802/4 (17.4),*0404/5 (3.2);*0403/6/7/11(3.7), *0101/2/4 (8.9),*1402/6 (4.7),*1101/2 (4.2). The structure of Mexicans published by us previously is concordant. Amerindian and Mediterranean alleles were prevalent. The most common A-B-DR-DQ haplotypes found for the patients were of Native origin (74.7%); Semitic (14.7%) and Cauc.(10.6%). The latter prevails in the N/NW Mexico, while the Native component in the center/southeast. No African alleles were detected. With more patients and the increase of the Registry size, low frequency alleles will show up. According to an analysis done by C. Müller, DONORMO may need 100,000 donors to get an A-B-DR match for 65 % of patients worldwide. In theory, we can find ~11% 6/6 match for Mexican patients. We also offer now, potential donors for other Latin American/Hispanic patients.