Acute hepatitis A and B in patients with chronic liver disease: prevention through vaccination.

Retrospective and prospective studies have demonstrated that the occurrence of acute hepatitis A in patients with chronic liver disease is associated with higher rates of morbidity and mortality than in previously healthy individuals with acute hepatitis A. The mortality associated with acute hepatitis A may be particularly high in patients with preexisting chronic hepatitis C. Although acute hepatitis B in patients with preexisting chronic liver disease is less well studied, worse outcomes than in previously healthy individuals are apparent. However, numerous studies convincingly demonstrate that chronic hepatitis B virus coinfection with hepatitis C virus (or hepatitis D virus) is associated with an accelerated natural history of liver disease and worse outcomes. These observations led to studies that demonstrated the safety and efficacy of hepatitis A and hepatitis B vaccination in patients with mild-to-moderate chronic liver disease. Hepatitis A and B vaccination is less effective in patients with advanced liver disease, especially after decompensation, such as in patients awaiting liver transplantation, and in liver transplant recipients. The emerging lower rates of inherent immunity in younger individuals, higher morbidity and mortality of acute hepatitis A or B superimposed on chronic liver disease, and greater vaccine efficacy in milder forms of chronic liver disease suggest that it is a reasonable policy to recommend hepatitis A and B vaccination in patients early in the natural history of chronic liver disease.