HLA alleles, haplotypes frequencies, and their association with hematological disorders: a report from 1550 families whose patients underwent allogeneic bone marrow transplantation in Egypt.

HLA alleles are representative of ethnicities and may play important roles in predisposition to hematological disorders. We analyzed DNA samples for HLA-A, -B, -C, -DRB1, and -DQB1 loci, from 1550 patients and 4450 potential related donors by PCR-SSO (Polymerase chain reaction sequence-specific oligonucleotides) and estimated allele frequencies in donors and patients from 1550 families who underwent bone marrow transplantation (BMT) in Egypt. We also studied the association between HLA allele frequencies and incidence of acute myeloid leukemia, acute lymphoblastic leukemia, and severe aplastic anemia. The most frequently observed HLA class I alleles were HLA- A01:01 (16.9%), A02:01 (16.1%), B41:01 (8.7%), B49:01 (7.3%), C06:02 (25.1%), and C07:01 (25.1%), and the most frequently observed class II alleles were HLA-DRB111:01 (11.8%), DRB103:01 (11.6%), DQB103:01 (27.5%), and DQB105:01 (18.9%). The most frequently observed haplotypes were A33:01~B14:02 ~ DRB101:02 (2.35%) and A01:01B*52:01DRB115:01 (2.11%). HLA-DRB107:01 was associated with higher AML odds (OR, 1.26; 95% CI, 1.02-1.55; p = 0.030). Only HLA-B38 antigen showed a trend towards increased odds of ALL (OR, 1.52; 95% CI, 1.00-2.30; p = 0.049) HLA-A02:01, -B14:02, and -DRB115:01 were associated with higher odds of SAA (A02:01: OR, 1.35; 95% CI, 1.07-1.70; p = 0.010; B14:02: OR, 1.43; 95% CI, 1.06-1.93; p = 0.020; DRB115:01: OR, 1.32; 95% CI, 1.07-1.64; p = 0.011). This study provides estimates of HLA allele and haplotype frequencies and their association with hematological disorders in an Egyptian population.