HLA analysis of Mexican candidates for bone marrow transplantation and probability of finding compatible related donors.

Introduction: Oncohematological disorders are the main cause of morbidity in the Mexican population from 1 to 19 years old, where megakaryoblastic and promyelocitic leukemias are more frequent. Considering that the success of a transplant is multifactorial, the criterion of compatibility in the HLA system is crucial and even more so when the source of HSC is bone marrow.

Objective: To determine the frequency of the HLA genotype in Mexican candidates who require a bone marrow transplant from related donors and the probability to find donors.

Materials And Methods: One hundred twenty-six candidates for bone marrow transplant and related donors were tested for HLA class I (-A*, -B* alleles) and class II (-DRB1* allele) in intermediate-resolution, as the first phase in the choice of the possible donor. The criteria to identify donors were determined by antigen-matched in each HLA haplotype as follows: 4/6, 5/6 and 6/6 at the HLA-A*, HLA-B*, and HLA-DRB1* alleles.

Results: Of all the candidates analyzed, 57.93%, at least one bone marrow donor was identified; in 53 cases, no donor was found. The average size of the families was 4.79 ± 1.06 members. A higher percentage of compatibility with grade 6/6 (31.6%) was identified with brothers, followed by sisters in 25.3%. The probability to find at least one compatible potential donor was 1.51 ± 0.92 donors.

Conclusion: In the first phase to select donors, Mexican patients studied in this work, have a compatible donor, however the grade of resolution test influenced in the probability identified.