Semiquantitative anti-HBc IgM detection in children with chronic hepatitis B: a long-term follow-up study.

Serum anti-HBc IgM titres were monitored monthly by a semiquantitative method in 14 children with HBeAg positive chronic hepatitis B followed up for 18-65 months. All patients, but one, were treated with alfa-interferon (IFN) at different times. On the whole, 12 flare-up episodes were observed and 7 patients cleared HBV-DNA and seroconverted to anti-HBe. Seroconversion occurred only in patients with pretreatment anti-HBc IgM index greater than 0.15 and serum HBV-DNA concentration below 100 pg/ml; the pretreatment alanine aminotransferase (ALT) value was not predictive of response. Combining anti-HBc IgM results and serum HBV-DNA levels observed during the pre-IFN period allowed a precise identification of patients who were likely to respond to IFN therapy. Patients who seroconverted to anti-HBe showed a progressive reduction in serum anti-HBc IgM titres within 6 months. Interestingly, one child, in whom HBV-DNA reappeared and who reconverted to HBeAg 7 months after treatment, showed no anti-HBc IgM decrease after the transient clearance of HBV-DNA and anti-HBe seroconversion. Semiquantitative anti-HBc IgM detection is a useful tool in the decision making process for children with chronic hepatitis B.