Microthrombotic renal involvement in an SLE patient with concomitant catastrophic antiphospholipid syndrome: the beneficial effect of rituximab treatment.

Antiphospholipid syndrome is characterized by multiple arterial and/or venous thrombotic events, recurrent fetal losses in the presence of antiphospholipid antibodies (aPL). Catastrophic antiphospholipid syndrome is a life-threatening, rare subset of antiphospholipid syndrome when the thrombotic events affect at least three organs, and clinical manifestations develop simultaneously or within a week. Diagnostically, small vessel occlusions can be detected by histopathology in the presence of aPL.