Significance of IgA type of anti-Hbc in children with chronic HBV infection

Significance of IgA type of anti-HBc (IgA-HBcAb) was studied in 47 children with chronically infected HBV. As liver damages developed, titers of IgA-HBcAb elevated regardless of age, sex, and status of HBe antigen/antibody system. Anti-HBc measured by RIA or PHA, IgA1, IgA2, and secretory component of IgA type of anti-HBc correlated with IgA-HBcAb, but they had weaker relation to liver damage than IgA1 which had strong correlation with IgA-HBcAb. IgA-HBcAb declined swiftly in accordance with recovery of liver damage in a child with chronic hepatitis. IgA-HBcAb remained at low levels when hepatitis C occurred in an asymptomatic carrier child having HBV. IgA-HBcAb, having good specificity and sensitivity as an indicator of liver damage due to HBV infection, is clinically useful.