Pulmonary capillaritis and alveolar hemorrhage associated with the antiphospholipid antibody syndrome

Pulmonary hemorrhage due to small vessel vasculitis is a well recognized complication of many autoimmune and collagen vascular disorders. The antiphospholipid antibody syndrome (APS) is a disorder associated with hypercoagulability, thrombocytopenia, and thromboembolic phenomena. Pulmonary manifestations include pulmonary embolism, pulmonary hypertension, and respiratory failure associated with diffuse pulmonary infiltrates. We describe a patient with the APS syndrome, without systemic lupus erythematosus, who developed pulmonary hemorrhage due to pulmonary capillaritis with evidence of perivascular immune complex deposition.