[HLA DRB1*, DQB1*, DPA1*, and DPB1* and their association with the pathogenesis of leukemia in the population of Venezuela].

Background: The HLA complex is involved in the pathogenesis of leukemia. Objectives: The presence of class II HLA alleles DRB1 *, DQB1 *, DPA1 *, and DPB1 * was evaluated in 47 patients with acute lymphoblastic leukemia (ALL) and 48 with chronic myeloid leukemia (CML) for comparison with 48 healthy volunteers in Zulia, Venezuela, and to evaluate potential associations of HLA with leukemia. Methods: Low- and high-resolution PCR-SSP was used for class II HLA regions DRB1 *, DQB1 *, DPA1 *, and DPB1 * following the instructions of KIT Olerup SSP Genovision. Results: Alleles HLA-DRB1*14, especially DRB1*14:21, -DPA1*1:06, -DPA1*01:03,-DPA1*02:01, and the haplotypes HLA-DPA1*01:03-DPB1*04:01, DPA1*01:03-DPB1*02:01, DPA1*01:03-DPB1*99:01, -DRB1*14-DPA1*01:03, -DRB1*15-DPA1*01:03 were associated with CML (RR > 3); alleles HLA-DRB1*13, -DQB1*02, -DPA1*01:05, -DPA1*01:09 and the haplotypes HLA-DPA1*01:09-DPB1*02:01, DPA1*01:09-DPB1*04:01 were protective (RR < 1). Alleles HLA-DQB1*04, -DQB1*05, -DPA1*1:06, -DPA1*01:07, -DPA1*1:08 had a positive association with ALL. Alleles HLA-DPA1*01:09, -DPA1*02:01, -DPB1*02:01, -DPB1*03:01 and the haplotypes HLA-DPA1*01:03-DPB1*04:02, -DPA1*01:09-DPB1*02:01, -DPA1*01:09-DPB1*04:01, -DPA1*02:01-DPB1*04:02 were negatively associated. Conclusions: The absence of associations with HLA-DRB1 * region in ALL and other association patterns identified suggest marked differences in the pathogenesis of leukemia, which suggests possible deficiencies in antigen presentation for ALL or potential effects of molecular mimicry in CML.