Immunity, inflammation and reservoir in patients at an early stage of HIV infection on intermittent ART (ANRS 141 TIPI Trial)

Objectives: The objective of this study was to assess clinical and biological changes during intermittent ART (I-ART) started early, with significant time spent on versus off ART, which has never before been studied in ART-naive patients with high nadir and current CD4 cell count.

Patients and methods: ART-naive HIV-1-infected patients with baseline CD4 ≥ 500/mm(3) and nadir CD4 ≥ 400/mm(3) received 2 years of I-ART (6 month periods on once-daily boosted-PI-based ART, alternating with 6 month periods without ART) in a 2 year, Phase II, non-comparative multicentre trial. The trial is registered with ClinicalTrials.gov, number NCT 00820118.

Results: The CD4 cell count remained ≥ 500/mm(3) at 2 years in all 44 patients included in the study. The mean 2 year count was higher than the mean count at baseline in 24 patients overall (55%; 95% CI 40%-69%) and in 20 (65%; 95% CI 48%-81%) of the 31 patients who fully adhered to the trial strategy. All but three of these latter patients had HIV-1 RNA concentrations below 50 copies/mL after each 6 month 'on' period. Only one strategy-related genotypic mutation (M184I) was detected. The HIV-1 DNA median load fluctuated, but it did not differ between month 0 and month 24 (2.8 versus 2.6 log10 copies/10(6) leucocytes, P = 0.29). Biomarkers of inflammation and endothelial activation remained stable between month 0 and month 24. Naive CD4, CD8+CCR5+ and CD8+CD38+ T cell numbers tended to decline. One patient developed Burkitt's lymphoma and 12 patients reported sexually transmitted infections.

Conclusions: In patients with high nadir and current CD4 cell counts, 2 year I-ART maintained the CD4 cell count above 500/mm(3), with no increase in the viral reservoir. Immune activation seems related to HIV replication, while inflammation seems to evolve independently and require specific attention.