HLA-B27 subtypes in Japanese with seronegative spondyloarthropathies and healthy controls.

Objective. To determine HLA-B27 subtype frequencies in Japanese patients with seronegative spondyloarthropathies (SpA) and healthy controls. Methods. We determined HLA-B27 subtypes of 20 Japanese patients with ankylosing spondylitis and one with Reiter's syndrome, and 11 healthy Japanese individuals using a polymerase chain reaction sequence specific oligonucleotide hybridization method specifically designed for the discrimination of B*2701-09. Results. 14 of 21 (67%) patients' and 9 of 11 (82%) controls were typed as B*2704. The remainder were B*2705. Conclusion. HLA-B*2704 and B*2705 are present in the Japanese population, the former being the predominant subtype of HLA-B27. Both subtypes are associated with SpA.