Kinetics of Bilirubin and Ammonia Elimination during Hemadsorption Therapy in Secondary Sclerosing Cholangitis Following ECMO Therapy and Severe COVID-19

In critically ill patients, liver dysfunction often results in coagulopathy and encephalopathy and is associated with high mortality. Extracorporeal clearance of hepatotoxic metabolites, including bilirubin and ammonia, aims to attenuate further hepatocyte damage and liver injury, resulting in decreased mortality. The efficacy of hemadsorption combined with conventional hemodialysis to eliminate bilirubin and ammonia to support the liver’s excretory function in acute liver injury has been described previously. However, the optimal use of liver support systems in chronic liver dysfunction due to secondary sclerosing cholangitis in critically ill patients (SSC-CIP) has not been defined yet. We herein describe the kinetics of successful bilirubin and ammonia elimination by hemadsorption in a patient with SSC-CIP after extracorporeal membrane oxygenation (ECMO) therapy for severe acute respiratory distress syndrome (ARDS) in a patient with coronavirus disease 2019 (COVID-19). During the course of the disease, the patient developed laboratory signs of liver injury during ECMO therapy before clinically detectable jaundice or elevated bilirubin levels. A diagnosis of SSC-CIP was confirmed by endoscopic retrograde cholangiopancreatography (ERCP) based on intraductal filling defects in the intrahepatic bile ducts due to biliary casts. The patient showed stable elevations of bilirubin and ammonia levels thereafter, but presented with progressive nausea, vomiting, weakness, and exhaustion. Based on these laboratory findings, hemadsorption was combined with hemodialysis treatment and successfully eliminated bilirubin and ammonia. Moreover, direct comparison revealed that ammonia is more efficiently eliminated by hemadsorption than bilirubin levels. Clinical symptoms of nausea, vomiting, weakness, and exhaustion improved. In summary, bilirubin and ammonia were successfully eliminated by hemadsorption combined with hemodialysis treatment in SSC-CIP following ECMO therapy and severe COVID-19. This observation is particularly relevant since it has been reported that a considerable subset of critically ill patients with COVID-19 suffer from liver dysfunction associated with high mortality.

Secondary sclerosing cholangitis: a lesser known side effect of pembrolizumab therapy

Introduction/Objective Immune check-point inhibitors have increasingly taken hold as mainstays of various cancer treatments, revolutionizing outcomes for individuals diagnosed with terminal malignancy. Hepatotoxicity is reported to occur in 2-10% patients, predominantly manifesting as a mixed cholestatic hepatitis pattern of injury. Cholangitis is a rare immune-mediated adverse event (irAE). We present a case of pembrolizumab-induced secondary sclerosing cholangitis presenting with multiple biliary strictures. Early recognition is crucial as these cases are resistant to treatment with steroids. Methods/Case Report 82-year-old woman with recurrent, metastatic, high grade urothelial carcinoma status post cystectomy and neoadjuvant chemotherapy, presented with new onset obstructive jaundice (alkaline phosphatase 958 U/L, aspartate aminotransferase of 331 U/L, alanine aminotransferase of 422 U/L, and total bilirubin of 19.8 mg/dL) following two weeks of pembrolizumab therapy. MRCP suggested intrahepatic biliary ductal dilation. ERCP showed multiple strictures involving hepatic bifurcation, left, right and intrahepatic ducts with beaded intrahepatic bile ducts. Liver biopsy showed expanded portal tracts with mixed inflammatory infiltrate, extensive bile duct injury, neutrophilic cholangitis, ductular proliferation, and perivenular cholestasis (10% dropout) concerning for mechanical obstruction. CK7 did not show ductopenia and immunostain IgG4 was negative. All autoimmune work-up was negative. Liver enzymes continued to rise despite multiple therapeutic stents, drains, high-dose corticosteroids, ursodiol and mycophenolate mofetil. The patient died five months later. Results (if a Case Study enter NA) NA Conclusion Pemrolizumab-induced secondary sclerosing cholangitis is a rare, hence under-recognized, adverse effect of check point inhibitor-mediated hepatotoxicity. It is important to recognize this association, as it has limited benefit from steroid therapy. Our finding of pembrolizumab-related SC adds to the growing body of literature of immune check-point inhibitor-related hepatobiliary injury and calls for further characterization of PD-1/PD-L1 inhibitor SC and its clinical implications.