title: Overestimation of the prevalence of antibody to hepatitis C virus in retrospective studies on stored sera.
abstract: Serum samples (1,428) from 1,149 patients with chronic liver diseases and polytransfused subjects were tested for antibody to hepatitis C virus by first-generation enzyme immunoassays. Antibody to hepatitis C virus was detected in 87% of patients with transfusion-related chronic non-A, non-B hepatitis; 17.6% of patients with nonmalignant, chronic hepatitis B virus infection; 37.3% of patients with hepatocellular carcinoma; 14.3% of patients with alcoholic liver diseases; 22.2% of patients with cryptogenic cirrhosis; 76% of intravenous drug abusers; 16.4% of patients on hemodialysis; 1.8% of patients on peritoneal dialysis; 6.2% of kidney transplant recipients; and 3.1% of normal subjects. A high frequency of weakly positive results was found in "aged" samples: 61.9% of antibody to hepatitis C virus-positive patients whose sera had been stored for more than 2 yr had optical densities less than two times the cut-off values in contrast to 7.9% of those whose sera had been stored for less than 2 yr (p less than 0.0001). A significantly lower proportion of patients who had optical densities less than two times the cut-off values were reactive in subsequent samples, 27.5% vs. 87.5% (p less than 0.0001). On retests, only 70% and 56% of sera that were initially positive for antibody to hepatitis C virus remained antibody to hepatitis C virus positive using second-generation enzyme immunoassays and neutralization enzyme immunoassays, respectively. Our results suggest that retrospective studies on stored sera may have overestimated the prevalence of antibody to hepatitis C virus.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, University of Hong Kong, Queen Mary Hospital.
authors.forename: A S
authors.initials: AS
authors.lastname: Lok
authors.forename: O C
authors.initials: OC
authors.lastname: Ma
authors.forename: T M
authors.initials: TM
authors.lastname: Chan
authors.forename: C L
authors.initials: CL
authors.lastname: Lai
authors.forename: H T
authors.initials: HT
authors.lastname: Chung
authors.forename: C P
authors.initials: CP
authors.lastname: Ng
authors.forename: J S
authors.initials: JS
authors.lastname: Lam
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis*; D001769:Blood / Q000276:immunology*; D001793:Blood Preservation; D001803:Blood Transfusion; D002908:Chronic Disease; D016174:Hepacivirus / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008107:Liver Diseases / Q000276:immunology; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D000914:Antibodies, Viral