"Black swan in the kidney": renal involvement in the antiphospholipid antibody syndrome.

The antiphosphospholipid antibody syndrome (APS) describes a clinical entity with recurrent thrombosis, fetal loss, thrombocytopenia in the presence of lupus anticoagulant and/or antibodies to cardiolipin. These antibodies may be associated with connective tissue diseases such as systemic lupus erythematosus (secondary APS) or be found in isolation (primary APS). Renal syndromes increasingly being reported in association with these antibodies include thrombotic microangiopathy, renal vein thrombosis, renal infarction, renal artery stenosis and/or malignant hypertension, increased allograft vascular thrombosis, and reduced survival of renal allografts. Although much has been understood concerning the biology of these antibodies and the pathogenesis of thrombosis, the optimal therapy remains to be elucidated. This article presents a historical review of the renal involvement in the antiphospholipid syndrome and discusses therapeutic options. Further research is needed.