IgM antibody response to the hepatitis C virus core protein in intravenous drug users.
To verify whether a solid-phase enzyme immunoassay for serum IgM antibodies to the hepatitis C virus (HCV) core protein (IgM anti-HCVcore) might be proposed as a surrogate test for serum HCV RNA, we studied 86 anti-HCV antibody-positive intravenous drug users. Serum HCV RNA was demonstrated by RT-PCR with primers derived from the 5' non-coding and the core region. IgM anti-HCVcore antibodies were found in 62/86 (72%) subjects; circulating HCV RNA was detected by the 5' noncoding assay in 53/86 samples (62%) and by the core region assay in 35/86 samples (41%). IgM anti-HCVcore reactivity was associated with core HCV RNA seropositivity (p < 0.05) but not with 5' noncoding HCV RNA seropositivity (p = NS). Patients infected by HCV type 1a were more-often positive for IgM anti-HCVcore (p < 0.05) and for core HCV RNA (p = 0.005) than patients infected by other HCV genotypes. IgM anti-HCVcore reactivity was significantly more common in subjects positive for core HCV RNA (p < 0.005) and in subjects aged > 30 years (p < 0.05). In conclusion, the IgM anti-HCVcore assay frequently tests positive in intravenous drug users, particularly when infected by HCV 1a, but is not a surrogate of testing for serum HCV RNA.
Toniutto
P
P
Department of Experimental and Clinical Pathology and Medicine, University of Udine, Italy.
Falleti
E
E
Gasparini
V
V
Fabris
C
C
Tisminetzky
S G
SG
Lombardelli
T
T
Pacco
P
P
Satta
A
A
Pirisi
M
M
D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D005260:Female; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology*; D006526:Hepatitis C / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000276:immunology*; D018936:Hepatitis C Antigens / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D008297:Male; D012367:RNA, Viral / Q000097:blood; D015819:Substance Abuse, Intravenous; D014758:Viral Core Proteins / Q000276:immunology*
D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D007075:Immunoglobulin M; D012367:RNA, Viral; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus; D000410:Alanine Transaminase