Therapeutic plasma exchange for thrombotic microangiopathy associated with pancreatitis in a child

Introduction: Thrombotic microangiopathy (TMA) is characterized by thrombocytopenia and microangiopathic hemolytic anemia (MAHA). These features reflect the presence of an active microvascular endotheliopathy. TMA has been reported as a rare complication of acute pancreatitis in adults, with good outcomes after therapeutic plasma exchange (TPE). Sparse pediatric literature addresses the association of TMA and pancreatitis, or the merit of TPE for this indication. Description: A 13-year-old obese male with no previous medical history was admitted to the pediatric intensive care unit for management of acute pancreatitis and kidney injury after two days of abdominal pain, nausea, emesis, and decreased urine output. After fluid resuscitation, his initial labs revealed a lipase of 8520U/L, AST 153U/L, ALT 150U/L, Hgb 14g/dL, WBC 23,000/uL, Platelets 58,000/uL, INR 1.3, BUN 37mg/dL and Cr 4.06mg/dL. A non-contrast CT scan confirmed radiographic evidence of acute pancreatitis. He was afebrile, with stable hemodynamics and a reassuring neurological exam. His hemoglobin decreased to 10.8g/dL 24 hours after admission with subsequent workup suggestive of hemolysis (haptoglobin < 30mg/dL, LDH 4898U/L, schistocytes on peripheral blood smear). A diagnosis of MAHA with thrombocytopenia was established and TPE was initiated. Common underlying conditions associated with TMA such as disseminated intravascular coagulation, infection, drug-induced, autoimmune disorders and malignancy were addressed and ruled out. Complement levels (C3 and C4) were normal, direct/indirect Coombs were negative and ADAMTS13 activity was normal (>60%). The patient received three days of TPE with improvement in platelet counts to 102,000/uL and decrease in LDH to 486U/L after the third session. Renal replacement therapy (RRT) was required for nine days after TPE with good recovery of renal function. He was discharged on hospital day 19 with downtrending Cr 0.78mg/dL and lipase 53U/L. He was tolerating a regular diet without volume restriction prior to discharge. Discussion: Thrombocytopenia and MAHA should raise a suspicion for TMA in children presenting with acute pancreatitis. Acute renal failure requiring RRT is a frequent comorbidity. TPE with RRT may be effective and lifesaving in these patients.