HLA B27 subtype distribution among patients with ankylosing spondylitis in eastern Turkey.

Human leukocyte antigen (HLA) B27 has a strong association with ankylosing spondylitis (AS) and other spondyloarthropathies. More than 70 subtypes of HLA B27 have been described. The present study investigated B27 subtype distribution among B27-positive patients with AS classified according to the modified New York criteria and healthy controls. Sequence-specific primer polymerase chain reaction technique was used for B27 subtyping of 43 unrelated patients with AS and 39 volunteer bone marrow donors. Among patients with AS, the male-female ratio was 6.2 and the mean age was 30 years. No relationship was found between the B27 subtypes and clinical and laboratory findings in patients with AS (p>0.05). Similarly, the frequencies of B27 subtypes did not significantly differ between patients and controls. In this study, B*2746, B*2749, and B*2767 subtypes were detected for the first time. Among B27 subtypes, the most common B27 alleles found in the patients and the controls were B*2702 and B*2705. In addition, B*2702 subtype was found predominantly in both patients (48.8%) and controls (46.2%). In conclusion, in addition to commonly encountered B*2702 and B*2705 HLA subtypes, a B*2749 subtype in a patient with AS and B*2746 as well as B*2767 subtypes in controls were determined for the first time.