Serological approaches to subtyping of HIV-1 in injecting drug users in Russia: evidence of subtype homogeneity at the main sites of the epidemic.

ABSTRACT

The aim of this study was to develop and evaluate a simple V3 peptide-based enzyme immunoassay (PEIA) for large-scale serotyping of HIV-1 specimens derived from injecting drug users (IDUs) in the Russian Federation. Two synthetic peptides were evaluated, named P1 (RKSIHIGPGRAFYATGD) and P2 (RTSVRIGPGQVFYKTGD), in an PEIA on 63 HIV-1 IDUs sera for which genotypes had been determined by heteroduplex mobility assay (HMA) and sequencing. The sensitivities of P1 (subtype B) and P2 (subtype A) were 87% and 75% respectively. Specificity of the assay was 100% for both peptides, with 100% predictive values of a monoreactive positive test for both peptides. Using the PEIA with peptides P1 and P2, we have serotyped 375 of 477 serum samples derived from IDUs in 4 main sites of the HIV-1 epidemic in Russia. The results demonstrated a high level of subtype homogeneity in all regions studied. In 3 of 4 territories, Tver' (n=345), and Rostov-on-Don (n=61) regions, and Krasnodar Kray (n=27), 100% of typable sera were found to belong to env subtype A. On the other hand, all specimens serotyped in the Kaliningrad region (n=38) belonged to env subtype B, and there is strong evidence that the recombinant gagAenvB virus which has caused the largest outbreak of HIV-1 in Russia is located in this region. At the present time another parental strain with gagBenvB genotype is of minor importance in the IDUs HIV-1 epidemic in Russia.