HLA-B27-associated arthropathy in childhood: long-term clinical and diagnostic outcome.

We conducted HLA-B27 tissue typing assessments on 430 consecutive children whose main symptom at presentation to our clinic was arthritis/arthralgia. Eighty-five of them (20%) had the B27 antigen. Thirty-six of these children were reexamined after a mean followup period of 8.9 years. Although most had definable rheumatic diseases, only 2 met the New York criteria for ankylosing spondylitis (AS). Children with HLA-B27 and arthritis/arthralgia, although at increased risk of developing AS, have diverse diagnostic and clinical outcomes. The AS criteria used to diagnose the disease in adults may not be appropriate for use in children.