S3265 The Double Take: Recurrent Idiopathic Pancreatitis Leading to Thrombotic Microangiopathy

Introduction: Pancreatitis results in over 250,000 hospitalizations per year. Common complications include pancreatic fluid collections, splanchnic thromboses, and pancreatic necrosis. Here we present a rare complication of pancreatitis: secondary thrombotic microangiopathy. Case Description/Methods: An 18-year-old man with past medical history of idiopathic pancreatitis presented with abdominal pain ongoing for several days. Labs on arrival were significant for leukocytosis (WBC 10.8 thou/cmm), hyperbilirubinemia (total bilirubin 2.5 mg/dL), and elevated lipase (7671 U/L). The right upper quadrant ultrasound was unremarkable. Within 48 hours of admission, his total bilirubin rose dramatically to 9.9 mg/dL with a predominant indirect component of 9.0 mg/dL. Additional labs were significant for thrombocytopenia (platelets 51 thou/cm). Magnetic resonance imaging abdomen with and without contrast showed findings consistent with uncomplicated acute interstitial edematous pancreatitis, but otherwise no biliary pathology was identified. Given the constellation of indirect hyperbilirubinemia and thrombocytopenia, there was concern for a hemolytic process. This was confirmed on peripheral smear showing schistocytes along with undetectable haptoglobin and elevated lactate dehydrogenase (1347 U/L). He was transferred to a tertiary care center due to concerns for possible thrombotic thrombocytopenic purpura; however, his ADAMTS13 level was normal. Ultimately, he was diagnosed with thrombotic microangiopathy secondary to acute recurrent idiopathic pancreatitis. His platelets reached a nadir of 31 thou/cm and total bilirubin peak of 11.9 mg/dL, but improved to 172 thou/cm and 1.3 mg/dL, respectively, at time of discharge after supportive measures and prednisone. Discussion: Thrombotic microangiopathy (TMA) secondary to acute pancreatitis is extremely rare, documented in few case reports. TMA occurs within days of the onset of pancreatitis. It is thought to arise from the systemic inflammatory response to pancreatitis, leading to endothelial injury, triggering activation of the coagulation cascade and platelet aggregation, forming microvascular thrombosis. This can then lead to microangiopathic hemolytic anemia, thrombocytopenia, and organ dysfunction. Secondary TMA is often indistinguishable from TTP and HUS, as all are characterized by schistocytes, elevated lactate dehydrogenase, low haptoglobin and thrombocytopenia. Primary management of secondary TMA is supportive care, although steroids may sometimes be utilized.