title: Assessment of specific antibodies to F protein in serum samples from Chinese hepatitis C patients treated with interferon plus ribavarin.
abstract: The hepatitis C virus (HCV) alternate reading frame protein or F protein of the HCV 1b genotype is a double-frameshift product of the HCV core protein. In order to assess the presence of antibodies specific for F protein and their clinical relevance in sera from HCV patients, we produced recombinant F protein and core protein of the HCV 1b genotype in Escherichia coli. An enzyme-linked immunosorbent assay was developed using purified recombinant HCV core, F protein, and a 99-residue synthetic F peptide (F99). The seroprevalences of anticore, anti-F protein, and anti-F99 synthetic peptide were 95%, 68%, and 36%, respectively, in 168 HCV patients. The prevalence of anti-F antibodies did not correlate with viral load, genotype, or alanine aminotransferase level. Interferon combination therapy induced a decline in the level of anti-F antibodies in 55 responders (P < 0.01). Thirteen responders (24%) lost their anti-F recombinant protein antibodies, and 17 (31%) lost their anti-F synthetic peptide antibodies, whereas no decrease was observed for the 17 nonresponders. These changes were significant between responders and nonresponders (P < 0.05). Meanwhile, no change was found in the anticore antibody titer of the 72 treated patients. The percentage of anti-F-protein-negative patients (15/15 [100%]) who achieved a sustained virological response (SVR) was higher than that of the anti-F-positive patients (70%) (P < 0.05). Based on these findings, HCV F protein elicits a specific antibody response other than the anticore protein response. Our data also suggest that the presence and level of anti-F antibody responses might be influenced by the treatment (interferon plus ribavirin) and associated with an SVR in Chinese hepatitis C patients.
authors.affiliation: Department of Infectious Diseases, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, 197 Ruijin Er Road, Lu-Wan District, Shanghai 200025, China.
authors.forename: De-Yong
authors.initials: DY
authors.lastname: Gao
authors.forename: Xin-Xin
authors.initials: XX
authors.lastname: Zhang
authors.forename: Gang
authors.initials: G
authors.lastname: Hou
authors.forename: Gen-Di
authors.initials: GD
authors.lastname: Jin
authors.forename: Qiang
authors.initials: Q
authors.lastname: Deng
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Kong
authors.forename: Dong-Hua
authors.initials: DH
authors.lastname: Zhang
authors.forename: Yun
authors.initials: Y
authors.lastname: Ling
authors.forename: De-Min
authors.initials: DM
authors.lastname: Yu
authors.forename: Qi-Ming
authors.initials: QM
authors.lastname: Gong
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhan
authors.forename: Bi-Lian
authors.initials: BL
authors.lastname: Yao
authors.forename: Zhi-Meng
authors.initials: ZM
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000410:Alanine Transaminase / Q000097:blood; D000998:Antiviral Agents / Q000627:therapeutic use*; D002648:Child; D002681:China; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D016174:Hepacivirus / Q000145:classification / Q000235:genetics; D006526:Hepatitis C / Q000188:drug therapy* / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D007372:Interferons / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins; D012254:Ribavirin / Q000627:therapeutic use*; D016036:Seroepidemiologic Studies; D013223:Statistics as Topic; D014758:Viral Core Proteins / Q000276:immunology*; D019562:Viral Load
chemical_list: D000998:Antiviral Agents; D018937:Hepatitis C Antibodies; D011994:Recombinant Proteins; D014758:Viral Core Proteins; C433031:hepatitis C protein F, Hepatitis C virus; C069130:nucleocapsid protein, Hepatitis C virus; D012254:Ribavirin; D007372:Interferons; D000410:Alanine Transaminase