A Case of Atypical Hemolytic Uremic Syndrome Superimposed on Behcet’s Disease

Behcet’s disease is a disorder that involves oral aphthous with genital ulcer, skin lesions, gastrointestinal, vascular, neurological diseases and systemic symptoms such as arthritis. Thrombophilia and vasculitis which may involve any vessel play a role in pathogenesis. aHUS is a syndrome which is characterized by microangiopathic hemolytic anemia, thrombocytopenia and renal failure. We would like to report a case of aHUS in a patient with Behcet’s Disease.
43 year old male patient was admitted to the emergency department with dyspnea for 3 days. In his medical history, 10 years ago Behcet’s Disease was diagnosed and treated with colchicine. At presentation his blood pressure was 140/80mm Hg, heart rate 116/min, respiratory rate 16/min and body temperature 98.9ºF. Laboratory studies revealed microangiopathic hemolytic anemia, thrombocytopenia, acute renal insufficiency, increaded serum bilirubin and lactate dehydrogenase levels, decreased haptoglobulin level leading to suspicion of TMA. Peripheral blood smear was significant for common schistocytes, anisocytosis and thrombocytopenia which were also suggestive for thrombotic microangiopathy.
ADAMTS13 level was normal. Pathogenic bacteria in stool microscopy and culture were not available. The patient underwent kidney biopsy consistent with TMA. All symptoms were consistent with a diagnosis of aHUS; 1gr/d methylprednisolone was administered for 3 days with 40mg/d steroid maintenance afterwards. Plasmapheresis therapy was done for 15 times. On the 12th day of treatment, the response was dramatic. Dyspnea was disappeared, hemoglobin increased, platelet number and LDH level normalized, and creatinine was better.
aHUS is a disease with high mortality that response dramatically to plasmapheresis and immunsuppressive therapy. Without any other predisposing factor in Behcet’s Disease, aHUS may develop de novo.