The majority of cases of hepatic failure in a patient with viral hepatitis A reflect acute infection in a patient with underlying chronic liver disease or cirrhosis (alcoholic liver disease, Wilson's disease, autoimmune hepatitis, cirrhosis, etc).
Risk factors for hepatic failure associated with viral hepatitis A without pre-existing liver disease:
(1) inheritance of a 6 amino acid insertion into TIMI1 (HAVCR1), which is the gene that encode the HAV receptor. The insertion is associated with greater NKT cell cytolytic activity against HAV-infected hepatocytes.
(2) genotype of the hepatitis A virus (possibly subgenotype IA, subgenotype IB, subgenotype IIIA)
Normal TIMI genes without the insertion are associated with allergy and asthma.
Inheritance of TIMI with the insertion should be suspected if there are cases of hepatic failure within a family (although this may indicate exposure to the same viral A subgenotype).
Poor survival in acute hepatic failure associated with viral hepatitis A is predicted by rapid clearance of viral RNA from the blood (with undetectable levels).
