[Development of an antigen 'sandwich' enzyme immunoassay for the detection of antibodies against HIV-2 by using a biotinylated synthetic peptide of gp36 protein].

Introduction: Among the several existing methods for the detection of antibodies to HIV, the 'sandwich' ELISA is currently the most used. This study aims to assess a biotinylated monomeric synthetic peptide of the glycoprotein trans-membrane gp36 from HIV-2, in a sandwich assay, for the detection of antibodies against this HIV-2 protein.

Materials And Methods: To perform the assay, plates coated with recombinant protein gp36 at 0.5μg/mL and synthetic peptide gp36(5) at 1μg/mL were used. The concentration of the biotinylated synthetic peptide (gp36(5)-B) used was 0.1μg/mL prepared with a Tris-BSA-NaCl buffer solution and the Streptavidin- Alkaline Phosphatase conjugate diluted 1:30000 prepared with a PBS-Sucrose-BSA solution. Positive serum samples to antibodies against HIV-1 and HIV-2 viruses (88 and 34, respectively) were tested, with 483 negative samples from blood donors and 96 serum samples to assess the analytical specificity. All the samples were tested using the UMELISA HIV 1+2 RECOMBINANT assay, and all positives were confirmed using a DAHIV-BLOT assay.

Results: Thirty four samples with antibodies against HIV-2 were assessed as positive for both coating variants. The highest specificity was obtained with the variant using the synthetic peptide gp36(5) in its coating. The antigen 'sandwich' assay developed by using gp36(5)-B enables the detection of antibodies against gp36 protein of HIV-2.