[Behavior of anti-HBc IgM in acute and chronic hepatitis].

Anti-HBV core IgM antibodies (anti-HBc IgM) were tested by RIA in the sera from 269 patients with acute viral hepatitis (AVH), from 39 patients with chronic HBSAg+ hepatitis (CH) at various stage of evolution, in 41 asymptomatic HBsAg carriers and in 30 healthy volunteers. Anti-HBc IgM were found in 100/108 HBsAg+ AVH, in 6/161 HBsAg--AVH, in 9/39 with CH and only 1 asymptomatic HBsAg carrier. Among the chronic patients with anti-HBc IgM, 3 were HBeAg+ and 6 were anti-HBe+. The test of anti-HBc IgM results useful in the early aetiological diagnosis of acute hepatitis since it is always positive in HBV acute hepatitis even in the subjects who early seroconvert to anti-HBs; the absence of anti-HBc IgM in the HBsAg+ acute hepatitis suggests other overinfecting agents. The presence of anti-HBc IgM in CH seems not to be related to an active viral replication.