The Frequency of HLA Class I and II Alleles in Pakistani Patients with Aplastic Anemia

Hematological disorders like Aplastic anemia are quite frequent in Pakistan. Human leukocyte antigen (HLA) system, have been implicated in the development of Aplastic anemia in various population-based studies, The aim of this study was to determine the role of the HLA Class I and Class II alleles in genetic susceptibility to Aplastic anemia in Pakistani patients. HLA A*, B* and DRB1* alleles were analyzed, in 61 Pakistani patients (Females n = 22, Males n = 39) and the control group consisted of 200 ethnically matched individuals (Females n = 89, Males n = 111). The allele frequency of DRB1*15 was found significantly higher in patients 0.36 (p = 0.001 with odds ratio = 1.97), as compared to the controls 0.212. Although DRB1*03 percent frequency was significantly higher in controls 0.175 (p = 0.023) with odds ratio = 0.514, as compared to patients 0.106.Therefore DRB1*15 emerged as a susceptible allele and DRB1*03 as a protective allele in Pakistani Aplastic anemia patients and control samples. No significant difference was found in allele frequencies of other HLA class I and HLA class II alleles for both patients and controls. Three haplotypes A*02 B*40 DRB1*15 (p = 0.021), A*31 B*51 DRB1*13 (p = 0.12) and A*33 B*58 DRB1*15 (p = 0.000) showed significant variations in the two groups.