Development of paroxysmal nocturnal haemoglobinuria in systemic lupus erythematosus: an unusual cause of portal vein thrombosis.

We report a case of a 60 year-old female with systemic lupus erythematosus (SLE) who was being managed with low-dose oral prednisolone. Four years later, she was admitted with pain in upper abdomen of 1 week duration. It was associated with ascitis and thrombocytopenia. Radiological investigations revealed portal vein thrombosis. There were no known local thrombophilic risk factors. Investigations ruled out any associated inherited or acquired hypercoagulable states. To evaluate the cause of thrombocytopenia, bone marrow aspiration was performed. Cells were subjected to flow cytometric examination, which revealed deficiency of CD55 and CD59 on granulocytes, indicating that a clone of cells with paroxysmal nocturnal haemoglobinuria had developed in this patient which had resulted in portal vein thrombosis. At this juncture, Ham test was also positive. The importance of considering rare possibilities of thrombosis at unusual site in patients with SLE is highlighted.