[Nephropathy in patients with primary antiphospholipid antibody syndrome].

Primary antiphospholipid antibody syndrome (APS) is characterized by abortion, thrombosis, thrombocytopenia and/or valvular disease and it is liable to complicate systemic lupus erythematosus (SLE). We carried out a study to investigate the clinical and renal pathological findings in five patients with APS, but not SLE. In the clinical findings, the patients had negative tests for proteinuria and hematuria, and their renal function and tubular function were within normal limits. In the light microscopic findings, three patients exhibited mild mesangial hypercellularity, and two had minor glomerular abnormalities. In immunofluorescent study, there were IgM and/or C3 depositions in the mesangial area in some cases, and in electron microscopic study, there were no special findings other than mesangial hypercellularity. In conclusion, nephropathy is a rare complication in patients with APS, unlike systemic lupus erythematosus.