[Case of lupus peritonitis with thrombus in the right atrium].

A 24-year-old woman with systemic lupus erythematosus (SLE) was admitted to our hospital because of diarrhea, vomiting, and epigastralgia. When she was diagnosed as SLE 5 years earlier, her renal function was normal and her urine protein excretion was 0.15 g/day. Renal biopsy revealed class V lupus nephritis, and she was treated with intravenous steroid (1 g methylprednisolone per day) for 3 days. The prednisolone dose was then reduced from 30 mg/day to 5 mg/day and maintained at that level until she was admitted to our hospital. Her abdominal X-ray, and CT scan showed massive ascites and excessive colonic gas. She was diagnosed as having ileus resulting from lupus peritonitis. The dose of prednisolone was increased up to 50 mg/day. After 1 week, the ascites disappeared and serum albumin and complement levels, lymphocyte count, and urine protein level returned to the normal range. When the prednisolone dose was reduced to 40 mg, however, UCG and an abdominal CT scan revealed thrombus in her right atrium, and inferior vena cava. Urokinase, argatroban and heparin were administered intravenously and warfarin was administered thereafter. Her thrombus gradually disappeared and she was discharged. These findings suggest that anticoagulation therapy is crucial for SLE patients with multiple complications receiving high-dose steroids.