Renal affection in patients with ankylosing spondylitis and psoriatic arthritis.

In a retrospective study of 148 patients with well-defined ankylosing spondylitis (AS), psoriatic arthritis (PSA) or reactive arthritis (ReA) an 11% prevalence of idiopathic hematuria, proteinuria, or cylinduria was found in the former two groups. None of the patients with ReA had unexplained pathological urinary findings. Such findings were associated with raised ESR and presence of peripheral arthritis in AS and with the duration of disease in PSA. No patient lacking sacroiliitis showed pathological urinary findings. We believe that such findings may reflect nephropathy associated with AS and PSA.