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H Verhaert

Publications and source records attributed to H Verhaert.

6 recordsLinked to original sources
PubMed1994

Evaluation of third-generation screening and confirmatory assays for HCV antibodies.

A third-generation (gen.) screening and immunoblot assay (Ortho EIA-3.0; Chiron RIBA-3 prototype), using antigens derived from the capsid and different nonstructural regions (NS3, NS4 and NS5) of the hepatitis C virus viral genome, were evaluated in comparison with the corresponding second-gen. assays (Ortho EIA-2.0; revised Ortho EIA-2.5; Chiron RIBA-2). In 203 depository sera of blood donors, positive in EIA-2.0, specificity of the screening assays was improved as shown by an increase in positive predictive value for viral carrier state from 0.23 (EIA-2.0) to 0.37 (EIA-2.5) and 0.52 (EIA-3.0). Comparing the confirmation patterns on RIBA-2 and RIBA-3, this amelioration was mainly due to the specific elimination of false-positive c22-3 and c100-3 reactions. Antibody response to the newly added NS5 antigen was not as prevalent as to the other antigens and had only a minor influence in sample allocation. In contrast, screening of 1,560 volunteer blood donors and 47 hemodialysis patients revealed 3 additional positive sera, only reacting with the NS5 antigen. However none of these isolated NS5 reactions could be confirmed on synthetic peptides [INNO-LIA: NS5(p)] and none was PCR positive. A documented seroconversion, detected earlier with EIA-3.0, was related to a better immunological response to the NS3 antigen and not to the additional NS5. From this pilot study third-gen. assays appeared extremely useful in the reevaluation of HCV-seropositive depository sera. However the additional value of the NS5 antigen in blood donor screening is still hypothetical and remains to be established in larger screening studies.

Antigens, Viral↗
PubMed1993

Hepatitis C virus confirmation in blood donor screening.

A combination of different enzyme immunoassays (EIAs) was used for the serological confirmation of sera that were positive in a hepatitis C virus (HCV) second-generation screening EIA. Different reaction patterns were related with the probability of the HCV-carrier state as determined by polymerase chain reaction (PCR). Five hundred and eight sera of volunteer blood donors were send for confirmation and at first reexamined with both Abbott and Ortho second-generation screening EIA. A group of 195 sera, positive in both assays, was further evaluated by the Abbott Supplemental Assay, the Monolisa anti-HCV and an EIA with only the amino terminal part of the nucleocapsid protein as antigen. In addition PCR on the 5'-noncoding region of the viral genome was performed. We observed that 75 of the 78 PCR-positive sera were found in a group of 89 sera that were strongly positive in the four EIAs used. Moreover all but 1 PCR-positive sera were reactive against the nucleocapsid protein of the virus. Hence we concluded that a genuine antibody response to the nucleocapsid protein is highly suggestive for the HCV-carrier state.

Blood Donors↗
PubMed1992

Confirmation of hepatitis C virus positive blood donors by immunoblotting and polymerase chain reaction.

In a series of 385 sera obtained from volunteer blood donors positive for the first-generation hepatitis C virus assay (Ortho), the viral genome was detected by polymerase chain reaction (PCR) in 89 sera (23%). Most PCR-positive sera were found positive with the c100-3 neutralisation assay (Abbott) and by two second-generation enzyme immunoassays (Abbott, Ortho). However overall specificity of these assays was rather low. By immunoblotting (Innogenetics and Chiron/Ortho) the specificity could be considerably improved and the best correlation with carrier state was obtained when analysing the results for lane-specific reaction: all 89 viral carriers and only 9 other donors had antibodies against structural 'core' epitopes. From the present data we can conclude that in screening a volunteer blood donor population the confirmation of antibodies against 'core' epitopes by immunoblotting is strongly associated with viral carriage.

Base Sequence↗