Cost-effective diagnosis of HIV-1 and HIV-2 by recombinant-expressed env peptide (566/996) dot-blot analysis

To characterize the recombinant env peptides, 566 (HIV-1) and 996 (HIV-2), for their ability to serodiagnose HIV-1 and HIV-2 infection. To develop a cost-effective dot-blot format for these peptides, and to evaluate its performance in a developing country laboratory.

The recombinant env peptides were evaluated using a select panel of sera (n = 327) with known serostatus from geographically diverse areas. A dot-blot assay was developed and tested on a second set of immunoblotted sera (n = 331) and further evaluated in the field on a third set of sera (n = 2718) from study populations.

All sera were evaluated by immunoblot with both HIV-1 and HIV-2 viral lysates. The recombinant env peptides were characterized in immunoblot assay before development of the dot-blot assay.

The 566 (HIV-1) peptide showed 100% sensitivity and specificity. The 996 (HIV-2) peptide performed similarly, but showed the presence of HIV-1 cross-reactive epitopes. When the two env peptides were used together, there was high specificity and sensitivity for detecting HIV-positive sera in both immunoblot and dot-blot formats. The dot-blot assay performed in the field showed slightly lower specificity and sensitivity for HIV diagnosis. The relative cost of this assay combined with non-commercial immunoblot confirmation was 10-fold lower than conventional commercial assays.

The 566 and 996 env peptides are appropriate antigens for HIV serotype diagnosis. A dot-blot assay using these peptides may be a useful cost-effective method for HIV diagnosis applicable in developing country laboratories.