Diagnostic usefulness of anti-HBc-IgM and anti-HD antibodies in acute viral hepatitis.

To evaluate diagnostic improvement achieved with the determination of antibody to hepatitis core antigen of IgM type (anti-HBc-IgM) and antibody to delta antigen (anti-HD) in acute type B hepatitis, 155 patients (of whom 100 were drug addicts) were studied, using these markers in association with the classical markers of viral hepatitis (anti-HBc, anti-HBs, anti-HAV-IgM and anti-cytomegalovirus antibodies). With classical diagnostic criteria, 121 patients would have been diagnosed as having B hepatitis (HBs Ag and/or anti-HBc antibody positive without anti-HBs antibody), 33 non A non-B hepatitis (all markers negative or anti-HBc and anti-HBs positive) and 3 A hepatitis (anti-HAV-IgM antibody positive). With the current markers, 89 were B hepatitis (anti-HBc-IgM antibody positive), 18 were simultaneous B and D infections (anti-HBc-IgM and anti-HD antibodies positive), 6 were D hepatitis (anti-HBc-IgM antibody negative and anti-HD antibody positive), 39 non-A non-B hepatitis (anti-HBc-IgM, anti-HD, HAV-IgM and anti-cytomegalovirus antibodies negative) and 3 hepatitis A. Of the 121 cases initially diagnosed as B hepatitis, only 79 were actually B hepatitis, 16 were simultaneous B and D infections, 6 D hepatitis, 18 non-A non-B hepatitis and 2 A hepatitis. Of the 33 cases considered to be non A non-B hepatitis, only 21 were really non-A non-B hepatitis; 10 were B hepatitis and 2 B and D hepatitis. When anti-HBc-IgM and anti-HD antibodies were determined, the initial diagnosis was modified in 54 of 155 cases (35 p. 100).(ABSTRACT TRUNCATED AT 250 WORDS)