Dual HIV-1 and HIV-2 infection in West Africa supported by synthetic peptide analysis.

Abstract

Double Western blot human immunodeficiency virus (HIV)-1 and HIV-2 antibody-positive patients have been reported from West Africa suggesting the phenomenon of double infection. To evaluate this possibility synthetic peptide analysis was performed on 58 sera from a West African population. Site-directed serologic studies based on the use of synthetic peptides located downstream of HIV-1 gp 41 and HIV-2 gp 36 have been shown to be type specific and well suited for discrimination between HIV-1 and HIV-2 antibody responses. When tested with radioimmunoprecipitation assay or Western blot 10 of these 58 serum samples were reactive with both HIV-1 gp 41 and HIV-2 gp 36; the remainder reacted with other combinations of HIV-1 and HIV-2 envelope glycoproteins. When submitted to an indirect enzyme-linked immunosorbent assay (ELISA) test in peptide 39 or 41.2.1 coated microtiterplate wells 3 reacted only with peptide 39 25 reacted only with peptide 41.2.1 and 30 reacted with both these peptides. To further investigate the double reactivity observed in these 30 sera 14 such samples were submitted to a classic competition ELISA test. The binding capacity of antibodies to peptide 39 was only inhibited by peptide 39; similarly the binding capacity of antibodies to peptide 41.2.1 was only inhibited by this peptide. No significant cross-reactions could be observed between the 2 peptides in any of the samples analyzed indicating the simultaneous presence of the 2 antibody species.