Elisa studies in ankylosing spondylitis.

Specific IgA antibodies were measured by ELISA against Klebsiella, E. coli and Candida antigens in five different groups: active ankylosing spondylitis (high ESR), inactive ankylosing spondylitis (normal ESR), healthy controls, psoriasis and rheumatoid arthritis. Elevated levels of IgA antibodies against Klebsiella were found only in active ankylosing spondylitis patients.