Renal diseases in ankylosing spondylitis: review of the literature illustrated by case reports.

Ankylosing spondylitis (AS) can be accompanied by extraarticular manifestations in the cardiovascular, pulmonary, neurologic and renal organs. Secondary renal amyloidosis is the most common cause of renal involvement in AS (62%) followed by IgA nephropathy (30%), mesangioproliferative glomerulonephritis (5%) as well as rarely membranous nephropathy (1%), focal segmental glomerulosclerosis (1%) and focal proliferative glomeruleonephritis (1%). Treatment associated nephrotoxicity may result from non-steroidal anti-inflammatory drugs or disease modifying agents.