Author(s): Prezlvarez L, Delgado E, Vega Y, Montero V, Cuevas T,
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Abstract OBJECTIVES: R5-tropic viruses are associated with HIV-1 transmission and predominate during the early stages of infection. X4-tropic populations have been detected in ~50\% of patients with late-stage disease infected with subtype B viruses. In this study, we compared the frequency of X4 tropism in individuals infected with HIV-1 CRF14_BG viruses, which have a V3 loop of subtype B, with a control group of individuals infected with subtype B viruses. METHODS: Sixty-three individuals infected with HIV-1 CRF14_BG (n = 31) or subtype B (n = 32) were studied. Similar proportions of newly diagnosed and chronically infected individuals were included in the subtype B and CRF14_BG groups. V3 sequences were obtained and coreceptor tropism was predicted using the Geno2pheno[coreceptor] algorithm. V3 net charge and 11/25 rules were also used for coreceptor prediction. RESULTS: Overall, X4 tropism was more frequent among individuals infected with CRF14_BG viruses (87.1\%) than subtype B viruses (34.3\%), a difference that was statistically highly significant (P = 0.00001). Importantly, the frequencies among newly diagnosed individuals were 90\% and 13.3\%, respectively (P = 0.0007). Characteristic amino acids in the V3 loop (T13, M14, V19 and W20) were identified at higher frequencies in CRF14_BG viruses (54\%) than subtype B viruses (0\%; P < 0.000001). CONCLUSIONS: CRF14_BG is the genetic form with the highest proportion of X4-tropic viruses reported to date in newly diagnosed and chronic infections. This suggests high pathogenicity for CRF14_BG viruses, potentially leading to rapid disease progression. CCR5 antagonists will be ineffective in most CRF14_BG-infected patients, even at early stages of infection.
This article was published in J Antimicrob Chemother
and referenced in Journal of AIDS & Clinical Research