Persistence of HBV-DNA in children with chronic hepatitis B who seroconverted to anti-HBs antibodies after interferon-alpha therapy: correlation with specific IgG subclass responses to HBsAg.
OBJECTIVE
We examined the persistence of HBV-DNA in sera collected 4-10 years after IFN-alpha therapy from patients with chronic hepatitis B who had seroconverted to anti-HBs antibodies. We also wanted to assess whether any association exists between HBV-DNA status and the IgG anti-HBs subclass responses.


METHODS
Sera were obtained from 38 patients and the following parameters were determined in each of them: (1) serological markers of HBV; (2) concentrations of IgM, IgG, IgA; (3) total IgG subclasses. HBV-DNA and IgG anti-HBs subclasses were determined in anti-HBs positive sera.


RESULTS
Four to 10 years after therapy, anti-HBs were found in 37 of 38 patients (GMT: 775IU/L). In 13 of them (35.1%) free and/or bound HBV-DNA was present in sera. Significant differences in the profiles of IgG anti-HBs were observed when the HBV-DNA status was considered. Patients with undetectable HBV-DNA responded mainly with IgG1 and/or IgG3, while in the HBV-DNA-positive group, a high contribution of IgG4 was found.


CONCLUSIONS
Our study showed that HBV-DNA may persist for a long time after IFN-alpha therapy despite the appearance of anti-HBs antibodies. The monitoring of specific IgG subclasses may be of predictive value for HBV-DNA persistence.
Gregorek
Hanna
H
Department of Microbiology and Clinical Immunology, The Children's Memorial Health Institute, 04 730 Warsaw, Poland. hgreg@czd.waw.pl
Dzierzanowska-Fangrat
Katarzyna
K
Woynarowski
Marek
M
Jóźwiak
Paulina
P
Witkowska-Vogtt
Ewa
E
Socha
Jerzy
J
Syczewska
Małgorzata
M
Madaliński
Kazimierz
K
D000293:Adolescent; D000328:Adult; D000936:Antigen-Antibody Complex / Q000097:blood; D000998:Antiviral Agents / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D004279:DNA, Viral / Q000097:blood; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D006515:Hepatitis B virus / Q000235:genetics / Q000302:isolation & purification*; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000276:immunology* / Q000821:virology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D016898:Interferon-alpha / Q000627:therapeutic use*; D008297:Male
D000936:Antigen-Antibody Complex; D000998:Antiviral Agents; D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D007074:Immunoglobulin G; D016898:Interferon-alpha