[Specific diagnosis and follow-up of HIV-1 group O infection: RES-O data].

INTRODUCTION: HIV-1 group O (HIV-O), mainly found in Cameroon, has a very high genetic diversity with consequences on the diagnosis and treatment of patients, requiring the development of specific tools.
OBJECTIVE: We present the currently available tools for the specific detection of HIV-O and its therapeutic monitoring, and the first RES-O data, a French network for the identification and monitoring of patients infected by HIV-O.
METHOD: The diagnosis of infection was confirmed by group-specific envelope serotyping. The viral load was assessed by a specific technique, LTR-O, developed in the laboratory and compared to the nonspecific kit RealTime HIV-1 (Abbott). The sequencing of antiretroviral target regions (Protease, Reverse Transcriptase (RT), Integrase and Gp41), was performed by specific primers. The analysis of resistance mutations was performed with the ANRS algorithm used for HIV-M.
RESULTS: HIV-O infection was confirmed for 117 patients. Measuring viral load showed the two techniques were equivalent, but with a tendency to under-quantification for the Abbott technique greater than 1 log for 5% of samples. 70 to 100% of the studied strains had at least 10 mutations in the Protease, four 4 in the RT, and one in Gp41, resulting in a natural genotypic resistance to some anti-retroviral molecules. DISCUSSION: The diagnosis and monitoring of HIV-O infection is now possible. However, the impact of this variant's natural polymorphism on response to treatment remains undocumented.