An Atypical Cause Of Atypical Hemolytic Uremic Syndrome

Atypical hemolytic syndrome is an extremely rare, life threatening, progressive disease. Approximately one to two cases per million are seen annually in the US (3,4). It is known to be associated with variety of conditions including infections, drugs, autoimmune conditions, vaccination, malignancy, organ transplantation, pregnancy, and metabolic conditions (11,13).We hereby describe a case of atypical hemolytic uremic syndrome associated with CABG surgery. A 58 year old female presented to the emergency department (ED) with three days of worsening shortness of breath and cold like symptoms including nausea, vomiting and rhinorrhea. Twenty six days prior to presentation she had undergone Coronary Artery Bypass Graft (CABG) for three vessel disease. The physical examination was unremarkable. Labs showed anemia, acute renal injury and thrombocytopenia. A peripheral smear demonstrated over 10 per high-power field of schistocytes. She was presumptively diagnosed with Thrombotic Thrombocytopenic Purpura (TTP) and started on plasmapheresis. ADAMSTS-13 was normal and autoimmune workup was negative. After an extensive workup she was diagnosed with Atypical Hemolytic Uremic Syndrome (aHUS). To our knowledge this is the first case of aHUS associated with CABG. In fact, there has been only one other case of aHUS related to cardiac surgery which was found in a child who underwent Tetralogy of Fallot repair (1)