Sensitivity of hepatitis C virus core antigen and antibody combination assays in a global panel of window period samples.

Background: Hepatitis C virus (HCV) antigen and antibody combination assays have been launched as a cost-effective alternative to nucleic acid testing (NAT) for reducing the antibody-negative window period (WP). Later, a HCV antigen chemiluminescence immunoassay (CLIA) became available.

Study Design And Methods: A panel composed of 337 HCV NAT-yield samples that were characterized for viral load (VL) and genotype was used to compare the sensitivity of two combination enzyme-linked immunosorbent assays (Monolisa, Bio-Rad; and Murex, formerly Abbott) and a HCV antigen CLIA (Abbott).

Overestimation of incidence of hepatitis B virus mixed-genotype infections by use of the new line probe INNO-LiPA genotyping assay.

The new version of the INNO-LiPA HBV genotyping assay (Innogenetics) developed to identify all hepatitis B virus (HBV) genotypes, A to H, has been evaluated in comparison with sequencing of PCR-amplified HBV DNA from 200 samples before or after cloning. The genotyping data obtained with INNO-LiPA were in agreement with those from direct sequencing in the 179 samples characterized by the two methods. INNO-LiPA revealed 28 mixed infections.

Use of an anti-hepatitis C virus (HCV) IgG avidity assay to identify recent HCV infection.

There is no reliable and simple diagnostic marker available to diagnose recent hepatitis C virus (HCV) infection. It has been shown that the avidity of specific IgG antibody is low in primary viral infection and increases with time. We report the development of an anti-HCV avidity assay derived from a commercially available test.

National survey of hepatitis B virus (HBV) polymorphism in asymptomatic HBV blood donors from 1999 to 2007 in France.

Background: Hepatitis B virus (HBV) diversity is characterized by eight genotypes correlated to eight hepatitis B surface antigen (HBsAg) subtypes, which differ in their geographical distribution.

Study Design And Methods: To establish virologic characteristics and the evolution of HBV diversity, we carried out a study over a 9-year period in HBV-infected French blood donors. HBsAg subtyping based on specific antibody method concerned 2901 donors, from whom 940 have been analyzed by an S-gene sequencing to determine genotypes and S-gene mutations.

Sensitivity of hepatitis B virus DNA transcription-mediated amplification testing in hepatitis B surface antigen-positive blood donations.

Background: The objective was to evaluate the performance of nucleic acid testing (NAT) in the detection of hepatitis B virus (HBV) infection in hepatitis B surface antigen (HBsAg)-positive blood donations.

Study Design And Methods: A total of 253 HBsAg- and anti-hepatitis B core antigen (HBc)-positive samples (50 hepatitis B e antigen [HBeAg]-positive and 203 anti-HBe-positive) from blood donations collected in France were studied. The samples were investigated with a blood screening assay (Procleix Ultrio, Chiron/Gen-Probe) in minipool (MP; x8) and in individual-donation (ID) testing.

Is an assay for simultaneous detection of hepatitis C virus core antigen and antibody a valuable alternative to nucleic acid testing?

Background: A new enzyme immunoassay based on the simultaneous detection of nucleocapsid proteins of hepatitis C virus (HCV) and anti-HCV (Monolisa HCV antigen-antibody Ultra, Bio-Rad) was evaluated as an alternative to nucleic acid testing (NAT) for the diagnosis of HCV infection during the window period in blood donations.

Study Design And Methods: The study included 107 sequential samples from 10 HCV seroconversion commercial panels; 81 samples were in the preseroconversion phase, and 26 were collected after seroconversion. All samples were tested with HCV antigen-antibody assay and the two minipool (MP) NAT procedures that are routinely used in France (transcription-mediated amplification in pools of 8 and COBAS AmpliScreen HCV test [Roche Diagnostic] in pools of 24 donations).

Simultaneous detection of hepatitis C virus (HCV) core antigen and anti-HCV antibodies improves the early detection of HCV infection.

To evaluate whether a new enzyme immunoassay developed for the simultaneous detection of hepatitis C virus (HCV) core antigen (Ag) and anti-HCV antibodies (anti-HCV Ab) (Monolisa HCV Ag/Ab ULTRA; Bio-Rad) could improve the early detection of HCV infection, we compared its sensitivity to that of anti-HCV, HCV core Ag, and HCV RNA assays. The populations studied included 12 blood donor samples positive for HCV RNA and HCV core Ag but negative for anti-HCV antibodies and 23 hemodialysis patients who developed anti-HCV Ab (seroconversion) during the follow-up. From these 23 individuals, 83 samples sequentially collected prior to seroconversion and 108 samples collected after seroconversion were tested.