Evaluation of a novel serotyping system for hepatitis C virus: strong correlation with standard genotyping methodologies.
Direct sequencing and analysis of viral genomes are definitive methods for identifying various hepatitis C virus (HCV) genotypes. However, HCV genome sequencing methods are cumbersome and unsuitable for analyzing large numbers of clinical samples. We have developed a convenient, reliable, and reproducible RIBA strip immunoblot assay system for determining HCV serotype. Briefly, the assay consists of an immunoblot strip on which there are five lanes of immobilized serotype-specific HCV peptides from the nonstructural (NS-4) and core regions of the genomes of HCV types 1,2, and 3. HCV serotype is deduced by determining the greatest intensity of reactivity to the NS-4 serotype-specific HCV peptide band in relation to the intensity of the human immunoglobulin G internal control bands on each strip. HCV core peptide reactivity is used only in the absence of NS-4 reactivity. We used this assay to successfully serotype a high percentage of sera from well-documented HCV-infected patients. Our serotyping results correlated 99% with the findings from the standard restriction fragment length polymorphism genotyping methods. Less than 5% of the serum samples were untypeable. For a selected group of alpha interferon-treated patients we observed that the nonresponders (76.2%) and a majority of the responders who relapsed (72.2%) had type 2 HCV infection. A small population (n= 8) of complete responders was split 3:4:1 as type 1, type 2, and type 3, respectively. Our data indicate that this new serotyping assay has the potential to be a highly specific and reliable method for typing of HCV infection in patients.
Dixit
V
V
Division of Digestive Diseases, UCLA School of Medicine 90095-7019, USA.
Quan
S
S
Martin
P
P
Larson
D
D
Brezina
M
M
DiNello
R
R
Sra
K
K
Lau
J Y
JY
Chien
D
D
Kolberg
J
J
D005838:Genotype; D016174:Hepacivirus / Q000145:classification*; D006526:Hepatitis C / Q000188:drug therapy / Q000821:virology; D018936:Hepatitis C Antigens; D006801:Humans; D015151:Immunoblotting / Q000379:methods*; D016898:Interferon-alpha / Q000627:therapeutic use; D011934:Reagent Strips; D015203:Reproducibility of Results; D012703:Serotyping / Q000379:methods*
D018936:Hepatitis C Antigens; D016898:Interferon-alpha; D011934:Reagent Strips