Dissociation of alanine aminotransferase values in acute hepatitis A patients with and without past experience to the hepatitis B virus.

Serological markers and peak serum alanine aminotransferase (ALT) values of 140 in-patients with acute hepatitis, either type A (n = 90), or type B (n = 50) were prospectively assessed. In 23 out of the 90 patients with acute hepatitis A, evidence of previous experience with hepatitis B virus (HBV) was found, whereas 35 out of the 50 patients with acute hepatitis B had past contact with hepatitis A virus (HAV). The mean peak ALT values [S.D.] were significantly higher in hepatitis A patients with previous experience with HBV (1413 [704] i.u./l), when compared to those without such experience (842 [464] i.u./l, P less than 0.001). Such a difference was not evident between acute hepatitis B patients, whether or not they had previous contact with HAV. We conclude that when acute hepatitis A is superimposed on past HBV infection an augmented transaminaemia, indicative of enhanced liver cell necrosis, takes place although a definite explanation is lacking. We suggest that individuals with markers of HBV infection should be early candidates for HAV immunization.