Genotypic algorithms for prediction of HIV-1 coreceptor usage need to be evaluated in a clinical setting. We aimed at studying (i) the correlation of genotypic prediction of coreceptor use in comparison with a phenotypic assay and (ii) the relationship between genotypic prediction of coreceptor use at baseline and the virological response (VR) to a therapy including maraviroc (MVC). Antiretroviral-experienced patients were included in the MVC Expanded Access Program if they had an R5 screening result with Trofile (Monogram Biosciences). V3 loop sequences were determined at screening, and coreceptor use was predicted using 13 genotypic algorithms or combinations of algorithms. Genotypic predictions were compared to Trofile; dual or mixed (D/M) variants were considered as X4 variants. Both genotypic and phenotypic results were obtained for 189 patients at screening, with 54 isolates scored as X4 or D/M and 135 scored as R5 with Trofile. The highest sensitivity (59.3%) for detection of X4 was obtained with the Geno2pheno algorithm, with a false-positive rate set up at 10% (Geno2pheno10). In the 112 patients receiving MVC, a plasma viral RNA load of <50 copies/ml was obtained in 68% of cases at month 6. In multivariate analysis, the prediction of the X4 genotype at baseline with the Geno2pheno10 algorithm including baseline viral load and CD4 nadir was independently associated with a worse VR at months 1 and 3. The baseline weighted genotypic sensitivity score was associated with VR at month 6. There were strong arguments in favor of using genotypic coreceptor use assays for determining which patients would respond to CCR5 antagonist.During the entry process of HIV-1 in the target cell, the interaction of the viral surface glycoprotein gp120 with a cellular chemokine receptor, the coreceptor, is an essential step, besides attachment to the CD4 receptor, and precedes the fusion of the viral envelope to the cell membrane. The V3 hypervariable loop of gp120 is involved in coreceptor binding. Two coreceptors are most commonly used in vivo: CCR5 and CXCR4 (1). Viral coreceptor use (i.e., usage of either CCR5 or CXCR4) differs between viral isolates. If CCR5-using isolates (R5 isolates) are by far predominant at the early stage of early infection and seem to be selected during HIV-1 transmission, CXCR4 usage (X4 tropism) will become more prevalent as the infection progresses, with approximately half of X4 or dual or mixed (D/M) tropism in antiretroviral-experienced patients with advanced HIV-1 disease (10).Maraviroc (MVC), a CCR5 inhibitor, binds specifically to CCR5 and blocks HIV-1 binding to this coreceptor (5). MVC has shown a potent antiviral effect in antiretroviral-experienced patients with R5 HIV-1 infection in a placebo-controlled trial (7) and is currently prescribed in this indication. As MVC has shown little activity in patients with X4 viruses, the determination of HIV-1 coreceptor use has become mandatory before the prescription of CCR5 inhibitors (8).
We report a seasonal increase of enterovirus D68 (EV-D68) cases in France, with 54 cases detected between 19 August and 14 November 2018. Molecular typing revealed that 20 of 32 of the isolates belonged to clade D1, only sporadically detected before in France. Median age of D1-cases was 42 years, 10 developed severe respiratory signs and one had neurological complications. The 2018-D1 viruses showed a genetic divergence of 3.34 % with D1 viruses identified previously.
the relative stability of rotavirus genotypes currently cocirculating in France may ensure vaccine effectiveness in the short and medium term. However, the likely emergence of G12 and G8 strains should be monitored during ongoing and future vaccination programs, especially as all genotypes can cause severe infections. Special attention should be paid to the emergence of new rotavirus reassortants not included in current rotavirus vaccines.
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