Plasma HIV-1 tropism and the risk of short-term clinical progression to AIDS or death. PLoS One
Casadellà et al. on behalf of EuroSIDA aimed to investigate if plasma HIV-1 tropism testing could identify subjects at higher risk for clinical progression and death in routine clinical management.
In this nested case-control study, cases were subjects with AIDS or who died from any cause, with a plasma sample with HIV-1 RNA >1000 copies/mL available for tropism testing 3 to 12 months prior to the event.
The study included 266 subjects, 100 cases and 166 controls; one quarter had X4 HIV; 26% were antiretroviral therapy (ART) naïve. Baseline tropism (presence of X4 HIV) was not associated with the risk of clinical progression or death in any of the analyses and there was no statistically significant difference in CD4+T-cell count slope between X4 and R5 tropism groups. In addition, there was no evidence that the difference in slope between X4 and R5 tropism varied by ART status. Exposures independently associated with risk of clinical progression to AIDS and/or to death from any cause were: female gender (OR = 2.13 vs. male), CD4+T-cell count (OR = 0.90 per 100 cells/mm3 higher), being on ART at the time of testing (OR = 2.72 vs. being off ART) and calendar year of sample (OR = 0.84 per more recent year).
In conclusion, the study-results suggest that the predictive role of plasma tropism in the context of people receiving cART with detectable VL is not helpful to identify subjects at higher risk for clinical progression. Clinicians should rather consider gender, CD4+ counts and virological outcomes of ART for that purpose.