Molecular and Clinical Epidemiology of CXCR4‐Using HIV‐1 in a Large Population of Antiretroviral‐Naive Individuals

Abstract

Baseline CD4 cell count, pVL, HIV-1 V3 sequence, and CCR5 Delta 32 genotype were the strongest determinants of CXCR4-using HIV-1 in this population. After adjustment for baseline parameters, the presence of X4 variants before initiation of highly active antiretroviral therapy was not independently associated with a poorer outcome of therapy.

Evaluation of Eight Different Bioinformatics Tools To Predict Viral Tropism in Different Human Immunodeficiency Virus Type 1 Subtypes

“…A significantly higher prevalence of X4 and X4/R5 dualtropic viruses was found in patients with lower CD4 counts, which is in agreement with previously reported observations and with the notion that these HIV-1 variants tend to be selected as immunodeficiency progresses (3,14,15,31). A higher prevalence of X4/X4R5 viruses also tended to be associated with prior exposure to antiretroviral therapy, which is also in agreement with previously reported observational data from cross-sectional surveys (11,19).…”

“…Overall, 69.7% were male and 61.4% were antiretrovirally experienced patients. The median viral load value was 4.4 log HIV RNA copies/ml, and the median CD4 count was 300 cells/mm 3 . The proportion of treatment-experienced patients was significantly higher in the group infected with clade B than in the group infected with non-B viruses (82.9% versus 54.3%, respectively; P ϭ 0.003).…”

HIV-1 dual/mixed tropic isolates show different genetic and phenotypic characteristics and response to maraviroc in vitro

“…In conclusion, our study shows that dual/mixed-tropic viruses are constituted by different species, whereby those with characteristics R5 + /X4 are genotypically and phenotypically similar to the pure-R5 isolates; thus the use of CCR5-antagonists in patients with R5 + /X4-tropic viruses may be a therapeuticoption that deserves further investigations.patients (prevalence, >80%) also in advanced stages of the disease (Brumme et al, 2005;Melby et al, 2006;Moyle et al, 2005;Wilkin et al, 2007), while X4-tropic viruses are restricted to advanced stages, and are associated with CD4-cell count decline. In addition, they are rarely observed in either drug naïve (<1%) or treatment-experienced patients (<5%) with preserved immunefunction (Brumme et al, 2005;Melby et al, 2006;Moyle et al, 2005;Wilkin et al, 2007;Simon et al, 2010).…”

“…In addition, they are rarely observed in either drug naïve (<1%) or treatment-experienced patients (<5%) with preserved immunefunction (Brumme et al, 2005;Melby et al, 2006;Moyle et al, 2005;Wilkin et al, 2007;Simon et al, 2010). Conversely, a quite high proportion of patients harbouring dual/mixed-tropic viruses has been observed both in drug-naïve (prevalence ranging 12-15%) and in treatment-experienced patients (prevalence ranging 20-50%) (Church et al, 2008;Huang et al, 2007;Lihana et al, 2009;Moreno et al, 2009;Shepherd et al, 2008).…”

HIV-1 Pathogenesis: The Virus

“…The appearance of CXCR4-using viruses (X4 viruses) is correlated with more rapid progression of disease, but it is still unclear if the evolution of these variants is the cause or a marker of rapid disease progression (Schuitemaker et al 1992;Brumme et al 2005;Hunt et al 2006). Both may be true.…”