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Hepatitis C virus (HCV) infection is a major burden to public health worldwide, affecting approximately 3%of the human population. Although HCV detection is currently based on reliable tests, the field of medical diagnostics has a growing need for inexpensive, accurate, and quick high-throughput assays. By using the recombinant HCV antigens NS3, NS4, NS5, and Combined, we describe a new bead-based multiplex test capable of detecting HCV infection in human serum samples. The first analysis, made in a singleplex format, showed that each antigen coupled to an individual bead set presented high-level responses for anti-HCVpositive reference serum pools and lower-level responses for the HCV-negative pools. Our next approach was to determine the sensitivity and specificity of each antigen by testing 93 HCV-positive and 93 HCV-negative sera. When assayed in the singleplex format, the NS3, NS4, and NS5 antigens presented lower sensitivity values (50.5%, 51.6%, and 55.9%, respectively) than did the Combined antigen, which presented a sensitivity of 93.5%. All antigens presented 100% specificity. These antigens were then multiplexed in a 4-plex assay, which resulted in increased sensitivity and specificity values, performing with 100% sensitivity and 100% specificity. The positive and negative predictive values for the 4-plex assay were 100%. Although preliminary, this 4-plex assay showed robust results that, aligned with its small-sample-volume requirements and also its cost-and timeeffectiveness, make it a reasonable alternative to tests currently used for HCV screening of potentially infected individuals.

The GSTM1 and GSTT1 null genotype frequencies were significantly different between 658 nonblack and black healthy blood donors from a Brazilian mixed population (Rio de Janeiro). The GSTM1 phenotype distribution was not in Hardy-Weinberg equilibrium in either group, mainly because of an excess of the GSTM1*A/*B genotype.