immunology allergic disorders
Liver Transplantation
Complications of Liver Transplantation
(See also Posttransplantation Complications .) Liver allografts are less aggressively rejected than other organ allografts for unknown reasons; hyperacute rejection occurs less frequently than expected in patients presensitized to HLA or ABO antigens, and immunosuppressants can often be tapered relatively quickly and eventually stopped. Most episodes of acute rejection are mild and self-limited, occur in the first 3 to 6 months, and do not affect graft survival. Risk factors for Rejection include Younger recipient age Older donor age Greater HLA mismatching Longer cold ischemia times Autoimmune disorders Worse nutritional status (eg, in alcoholism) appears protective. Symptoms and signs of rejection depend on the type of rejection (see table Manifestations of Liver Transplant Rejection by Category ). Symptoms of acute rejection occur in about 50% of patients; symptoms of chronic rejection occur in Rejection Category Manifestations Hyperacute Fever, very elevated liver function test results (AST, bilirubin), coagulopathy Accelerated Fever, coagulopathy, very elevated liver test results (AST, bilirubin), ascites Acute Anorexia, pain, fever, jaundice, light (clay)-colored stools, dark urine, elevated liver test results (AST, bilirubin) Chronic Jaundice, vanishing bile duct syndrome (with elevated bilirubin, alkaline phosphatase, and gamma-glutamyl transpeptidase), slightly elevated liver test results (AST, bilirubin), ascites AST = aspartate aminotransferase. Differential diagnosis of acute rejection includes viral hepatitis (eg, cytomegalovirus or Epstein-Barr virus infection; recurrent hepatitis B, C, or both), calcineurin inhibitor toxicity, and cholestasis. Rejection can be diagnosed by percutaneous needle biopsy if the diagnosis is unclear clinically. Suspected rejection is treated with IV corticosteroids;antithymocyte globulinis an option when corticosteroids are ineffective (in 10 to 20%). Retransplantation is tried when rejection is refractory to immunosuppressants. Immunosuppression contributes to recurrence of viral hepatitis in patients who had viral hepatitis-induced cirrhosis before transplantation. Hepatitis C recurs in nearly all patients; usually, viremia and infection are clinically silent but may cause active hepatitis and cirrhosis. Risk factors for clinically significant reinfection may be related to the Recipient: Eg, older age, HLA type, and hepatocellular carcinoma Donor: Eg, older age, fatty infiltration, prolonged ischemic time, and living donor Virus: High viral load, genotype 1B, and failure to respond to interferon Postprocedural events: Immunosuppressant doses, acute rejection treated with corticosteroids, and cytomegalovirus infection Newer antiviral therapies (eg, telaprevir) have transformed therapy of patients with hepatitis C-related cirrhosis. Donor organs from patients with hepatitic C virus infection are used increasingly, partly because a larger proportion of the US population is addicted to opioids and thus using contaminated needles. Outcomes have been excellent. Cure rate for hepatitis C is close to 100%, and treatment after successful liver transplantation in immunosuppressed patients is equally effective. Hepatitis B recurs in all patients but can be successfully managed with antiviral drugs; coinfection with hepatitis D appears protective against recurrence. Early complications(within 2 months) of liver transplantation include Primary nonfunction (ie, liver never functions and need to be replaced emergently) in 1 to 5% Mechanical biliary dysfunction (eg, ischemic anastomotic strictures, bile leakage, ductal obstructions, leakage around T-tube site) in 15 to 20% Portal vein thrombosis in < 5% Hepatic artery thrombosis in 3 to 5% (especially in small children or recipients of split grafts) Hepatic artery mycotic aneurysm or pseudoaneurysm and hepatic artery rupture Typically, symptoms and signs of early complications include fever, hypotension, and abnormal liver test results. Themost common late complicationsare Intrahepatic or anastomotic bile duct strictures, which cause symptoms of cholestasis and cholangitis After liver transplantation with deceased donor grafts, strictures are particularly common, occurring in about one fourth to one third of recipients. Strictures can sometimes be treated endoscopically or using percutaneous transhepatic cholangiographic dilation, stenting, or both, but they often ultimately require retransplantation. 