HLA-B27 subtypes in Turkish patients with ankylosing spondylitis and healthy controls

The aim of this study was to determine human leukocyte antigen (HLA)-B27 subtypes frequency in ankylosing spondylitis (AS) and related spondyloartropathy (SpA) patients. Therefore, we investigated the differences in HLA-B27 subtypes between HLA-B27-positive patients and controls. Sixty six patients were included in this study (51 AS and 15 SpA). Thirty-five individuals were diagnosed with leukemia or chronic renal failure, and their donors without any rheumatological problem (no SpA history) were selected as the control group. HLA-B27 subtyping was performed by PCR-SSP (polymerase chain reaction with sequence-specific primer) method in serologically HLA-B27-positive 46 AS patients, 9 SpA patients and control group. When the frequency of HLA-B27 was 4.5% in Turkish population, this frequency was 90.2% in AS patients. Four different HLA-B27 subtypes found in AS patients were B*2705 (65.2%), B*2702 (26.1%), B*2704 (6.5%) and B*2707 (2.2%). In SpA patients, B*2705 and B*2702 found in equal frequency. Five B27 alleles were identified in our control group: B*2705 (54.3%), B*2702 (31.4) %, B*2703 (2.9%), B*2704 (2.9%) and B*2702/B*2705 (8.5%). Both in the patient group and in the control group, we also observed B*2705 as most frequent allele, and B*2702 was second common allele. Our results show that the frequency of HLA-B27 subtypes is not significantly different between patients and controls (P > 0.10).