Antiphospholipid Antibody Syndrome

This biopsy shows glomerular arteriolar and capillary thrombi characteristic of thrombotic microangiopathy (TMA). Immunofluorescence studies (not shown) are negative for significant glomerular or tubulointerstitial immune complex deposits.

The clinical history corresponding to such findings might involve an adult female patient with a history of rheumatoid arthritis and multiple miscarriages who presents with non-nephrotic range proteinuria, microscopic hematuria, hypertension, and no mental status changes. Laboratory workup could show thrombocytopenia, elevated LDH, low haptoglobin, and a positive lupus anticoagulant, and imaging studies might confirm findings of systemic thrombosis. A clinical diagnosis of antiphospholipid antibody syndrome related to underlying autoimmune disease (rheumatoid arthritis) would be suspected.