Spondylarthropathy and selective IgA deficiency.

No serum IgA was detected in a young male patient suffering from spondylarthropathy (SpA) with bilateral sacroiliitis arthritis, enthesopathy and inflammatory low back pain, whose symptoms occurred in reaction to a sexually induced urethritis. After a period of several months in which the spondylarthropathy was active, disease activity came to a rest. Three years later no progression of the SpA was observed. This finding might be an indication that IgA is not involved in the pathogenesis of spondylarthropathy.