human leukocyte antigen b27 in 453 asian indian patients with seronegative spondyloarthropathy

background: spondyloarthropathies are a group of closely related inflammatory arthritis which involve the axial skeleton and are negative for rheumatoid factor. objective: this case-control study was conducted to examine hla- b27 positivity in patients with seronegative spondyloarthritis (ssa) as per essg criteria and compare the frequency with healthy controls because a lower positivity is reported in indians. method: the study included 453 patients and 200 controls. hla -b27 typing was done by microlymphocytoxicity and/or by sequence specific primers (ssp) using commercial kits. patients were categorised as ankylosing spondylitis (as), undifferentiated spondyloarthropathy, ssa with inflammatory bowel disease, reactive arthritis, psoriatic arthritis and juvenile spondyloarthropathy. results: hla-b27 antigen was present in 56% of patient and 3.5% controls with highest frequency in juvenile spondyloarthropathy (80%), followed by as (76%). the p value < 0.001 for all categories of ssa and overall odds ratio was 34.9. conclusion: this study showed hla-b27 frequency slightly lower than reported in caucasian ssa patients and in our opinion hla- b27 testing is extremely useful in young patients with suspected ssa.