Thrombotic thrombocytopenic purpura in a patient with rapidly progressive glomerulonephritis with both anti-glomerular basement membrane antibodies and myeloperoxidase anti-neutrophil cytoplasmic antibodies.

A 61-year-old Japanese woman with rapidly progressive glomerulonephritis exhibited both anti-glomerular basement membrane (GBM) antibodies (920 EU) and myeloperoxidase anti-neutrophil cytoplasmic antibodies (MPO-ANCA; 66 EU). Multiple plasma exchanges with fresh frozen plasma preceded by 500 mg/day intravenous methylprednisolone and 30 mg/day oral prednisolone decreased anti-GBM antibody and MPO-ANCA antibody titers to 106 EU and below 10 EU (normal ranges), respectively. Thrombotic thrombocytopenic purpura (TTP) manifests itself as a moderate decrease in the activity of disintegrin-like and metalloproteinase with thrombospondin type 1 motif, 13 (ADAMTS13) protein levels to 35% of normal; ADAMTS13 deficiency is only symptomatic when levels are less than 50%. This patient's disease was resistant to extensive plasma exchange, leading to her death from respiratory distress and perforation of the alimentary tract secondary to cytomegalovirus infection. Autopsy demonstrated severe crescentic glomerulonephritis associated with linear IgG, IgA, IgM, and C3 deposits along the glomerular capillary walls. This case is an uncommon example of combined double antibody-positive crescentic glomerulonephritis and refractory TTP.