Diagnostic value of anti-GBV-C antibodies in HIV-infected patients.

The beneficial effect of co-infection by GB virus C (GBV-C) in the course of the disease in human immunodeficiency virus (HIV)-infected patients has been described, although its mechanism of action is yet to be determined. The role of anti-GBV-C antibodies in HIV-infected patients also remains unknown. At present, there are no commercial systems to detect specific markers of GBV-C infection. The research presented follows our previous work from which we obtained chimeric molecules formed by two domains of different GBV-C proteins with good sensitivity/specificity balances in the detection of anti-GBV-C antibodies in hemodialyzed and chronic hepatitis patient samples. It has been investigated the ability of the synthetic peptides to recognize specific anti-GBV-C antibodies in HIV and HCV/HIV co-infected patients by a peptide-based ELISA immunoassay. The results showed that human immunodeficiency virus-infected patients have a significantly higher frequency of anti-GBV-C antibodies than healthy controls. A comparison between HCV(+)/HIV(+) and HCV(-)/HIV(+) was analyzed. Although a higher percentage of HCV/HIV-positive sera were positive for antibodies against GBV-C peptides, the difference was not significant. The presence of anti-GBV-C antibodies could represent a good marker of exposure to GBV-C in HIV-infected patients to facilitate a further analysis of the effect of this exposure in the progression of illness caused by HIV infection.