HIV-1 group O infection in France: clinical features and immunovirological response to antiretrovirals

Abstract

Objectives

To obtain reliable data on the clinical features of HIV-1/O infection, and on the immunological and virological responses to cART, based on a large series of 101 patients.

Methods

Piecewise linear models were used to estimate CD4 cell count before and after cART initiation. Kaplan-Meier survival curves were used to estimate time to reach clinical stage CDC C before ART, and to analyze the time to achieve a plasma viral load (pVL) <40 cp/mL following cART initiation. Immuno-virological response was also assessed at the most recent visit in patients on active follow-up.

Results

Data on natural course of the infection showed a 16.6% cumulative probability of reaching stage C within 5 years following HIV diagnosis, and a mean decrease of CD4 count of -30.5 cells/mm3/year. cART initiation in ART-naive patients led to a mean gain of +147 CD4/mm3 after 12 months, and to a median pVL of <40 cp/mL after 3.8 months for 89.3%. Initiation with a non-recommended NNRTI- versus a PI/r-based regimen resulted in a much smaller gain of around 100 CD4/mm ³ after one year. Patients still on follow-up since 2007 had a median CD4 of 498/mm3 and 87% had a pVL<40cp/mL at the most recent follow-up visit.

Conclusion

This work provides unique data on HIV-1/O infection, in favor of a milder natural evolution relative to HIV-1/M, and of a highly efficient current management, based on HIV-1/M guidelines, despite the genetic divergence. Studies of comparable HIV-1/M and HIV-1/O populations are now needed to confirm these results.