Atypical Hemolytic Uremic Syndrome Secondary to Pancreatitis: A Case Report.

This is a report of an extremely rare case of an atypical hemolytic uremic syndrome (aHUS) that appears to have been triggered by acute pancreatitis. A 68-year-old man was examined at a medical institution because of sudden lower abdominal pain. The patient was diagnosed with acute pancreatitis on computed tomography. Hemoglobinuria and laboratory findings indicative of intravascular hemolysis were noted. Biochemical analysis revealed normal results for von Willebrand factor activity, antiplatelet antibodies, and ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13), and stool culture was negative for Shiga-toxin-producing Escherichia coli, leading to the diagnosis of aHUS. Treatment for acute pancreatitis resulted in improvement in the laboratory findings, and the patient's progress was monitored without treatment intervention for aHUS. On day 2 of hospitalization, the abdominal symptoms and hemoglobinuria resolved without any subsequent recurrence. In the absence of any complications, the patient was transferred back to the initial hospital on day 26 of hospitalization. When hemolytic anemia or thrombocytopenia of unknown etiology is observed, aHUS should be suspected, and clinicians should be aware that acute pancreatitis may be a potential cause of aHUS.