[IgM anti-HBc in the differential diagnosis of co- and HDV superinfection].

EIA was used to study the titers of IgM anti-HBc in 38 patients with chronic hepatitis B, 10 with acute viral hepatitis B and 18 patients with D-infection (6 with coinfection and 12 with D-superinfection) depending on the presence of HBe/anti-HBe. Chronic active hepatitis (CAH) was diagnosed in 18 patients, chronic persistent hepatitis (CPH) in 15, and the "healthy" HBsAg carriership in 5. The titers of IgM anti-HBc 1:100 were detectable in 14 out of the 18 patients with CAH and in 3 out of the 15 patients with CPH and correlated with the clinico-biochemical activity of the process and the presence of HBeAg in serum. In coinfection, the antibody titers were determined in the range of the antibody titers were determined in the range of 1:3200 to 1:25600 for the first two weeks of the disease and did not depend on the presence of HBe/anti-HBe. Anti-D were identified only on the 3d week since the first disease manifestations. In the presence of the replicative form of CAH, HDV-superinfection was diagnosed in 3 patients with HBeAg in serum and the titers of IgM anti-HBc 1:100 and higher. The follow-up studies demonstrated inhibition of HBV replication shown up by HBeAg elimination from serum and a decrease in the titers of IgM anti-HBc. Therefore, the titers 1:100 cannot serve as a diagnostic criterion for coinfection, for in the replicative form of CAH, their concentration may be higher.(ABSTRACT TRUNCATED AT 250 WORDS)