Selective IgA deficiency and spondyloarthropathy: a distinct disease?

A woman with selective IgA deficiency and severe ankylosing spondylitis (AS), complicated by intractable peripheral arthritis, is described. Three previous cases of selective IgA deficiency and AS have been reported, all of whom had severe AS. It is suggested that selective IgA deficiency is a poor prognostic factor in AS and therefore warrants further investigation to determine the clinical course of such patients.