Enhanced Sensitivity of a Second Generation ELISA for Antibody to Hepatitis C Virus

Abstract

A second generation ELISA for combined detection of antibodies to three hepatitis C virus (HCV) recombinant proteins, i.e. C100, C33c and core, was compared with a first generation anti-HCV ELISA in which only antibodies to C100 are detected. The results of the ELISAs were evaluated in 225 haemophilia patients (panel A) and 44 patients with non-A, non-B (NANB) hepatitis (panel B). HCV infection was established by cDNA-polymerase chain reaction (PCR) (in panel B only) and by studying the anti-HCV reaction patterns in 4 separate ELISAs for detection of antibodies to the recombinant proteins C100, C33c, core and a combination of two synthetic peptides sp67/65 derived from the C100 region. The sensitivity for the detection of HCV infection had increased from 0.92 [95% confidence interval (Cl) : 0.87-0.95] to 1.00 (95% Cl: 0.98-1.00) in haemophiliacs and from 0.84 (95% Cl: 0.66-0.95) to 1.00 (95% Cl: 0.89-1.00) in NANB hepatitis patients when the second generation ELISA was used instead of the first generation ELISA. Concurrently the chance of a false negative result was reduced in panel A and B from 0.37 to 0 and from 0.28 to 0, respectively. Analysis of anti-HCV reaction patterns revealed that 172 of 206 (83.5%) anti-HCV ELISA-reactive haemophilia patients had antibodies to all 4 antigens tested. In the NANB hepatitis patients 18 of 31 (58.1%) anti-HCV ELISA-reactive subjects reacted with 4 antigens. In the PCR tested panel of NANB hepatitis patients 2 subjects who showed antibody reactivity to only one antigen and 5 patients with reactivity to 2 antigens were PCR-positive. On the other hand, 1 NANB hepatitis patient showed antibody reactivities to all 4 antigens tested, but was PCR-negative. Antibodies to core were the most prevalent in the two populations studied. We conclude that the introduction of the second generation anti-HCV ELISA will significantly reduce the likelihood of unrecognized HCV infection.

Antibody responses to hepatitis C envelope proteins in patients with acute or chronic hepatitis C

“…To increase the sensitivity and specificity of the tests, both HCV structural and nonstructural proteins were used as target antigens in second-generation assays. These tests, which allowed the detection of antibodies against recombinant proteins from NS4 (c100-31, C (c22-31, and NS3 (c33c) regions, have exhibited higher sensitivity [Bresters et al, 1992;Katayama et al, 19921. More recently, third-generation assays were developed including parts of C, NS3, NS4, and NS5 proteins Wernelen et al, 19941. Due to the improvement in the antigenicity of the NS3 and NS4 proteins, these tests have greatly ameliorated the sensitivity and specificity of HCV antibody detection [Pawlotsky et al, 1994;Uyttendaele et al, 19941.…”

Hepatitis C virus infection in patients with leukemia

“…However, a number of reports questioned the sensitivity and specificity of first-generation assays [4-61. Secondgeneration assays, which include polypeptides that are additional gene products (core and putative-protease epitopes), were reported to have enhanced sensitivity for anti-HCV [7,8]. We have studied 30 patients with leukemia by the second-generation assay for anti-HCV to determine the incidence of HCV infection and the impact of anti-HCV positivity on liver disease.…”

Routine HCV PCR screening of blood donations to identify early HCV infection in blood donors lacking antibodies to HCV

“…Hepatitis C virus (HCV) was discovered and cloned in 1989 1 . The availability of anti‐HCV tests in 1990 immediately led to routine blood donor screening that detected most of the HCV‐positive blood donors 2–4 . Despite continuous reductions in the risk of transmission of viral infections to transfusion recipients by means of improved donor selection and serologic screening assays, HCV transmission is still a major problem.…”