Rapid viral rebound after analytical treatment interruption in patients with very small HIV reservoir and minimal on-going viral transcription

Abstract

Introduction: Viral remission after analytical treatment interruption (ATI), termed post-treatment control, has been described in a small proportion of HIV-positive patients. This phenomenon has been separately associated to both low levels of HIV-1 proviral DNA as well as cell-associated RNA. We investigated whether the combination of both parameters could help predict delayed viral rebound after treatment interruption (TI).

Methods: We conducted an open single-arm ATI study in four Belgian HIV reference centres from January 2016 to July 2018. Eligible participants were adults who had fewer than 50 HIV-1 RNA copies/mL for more than two years, more than 500 CD4 cells/µL for more than three months, and were in general good health. Consenting participants who had fewer than 66 copies total HIV-1 DNA (t-DNA) and fewer than 10 copies cell-associated HIV-1 unspliced RNA (US-RNA) per million peripheral blood mononuclear cells (PBMCs), interrupted therapy and were monitored closely. Antiretroviral therapy (ART) was resumed after two consecutive viral loads exceeding 1000 copies or one exceeding 10,000 copies/mL. The primary outcome was the proportion of participants with fewer than 50 HIV-1 RNA copies/mL 48 weeks after TI. Secondary outcomes were time to viral rebound, the frequency of serious adverse events (AEs) and evolution of t-DNA and US-RNA after TI.

Results: All 16 consenting participants who interrupted therapy experienced rapid viral rebound two to eight weeks after TI. No serious AEs were observed. Levels of t-DNA and US-RNA increased after TI but returned to pre-ATI levels after treatment restart. None of the studied demographic, clinical and biological parameters were predictive of time of viral rebound.

Conclusions: The combination of low levels of t-DNA and US-RNA in PBMCs, corresponding respectively to a small and transcriptionally silent viral reservoir, is not predictive of viral remission after TI in patients on ART.

Trial registration: ClinicalTrials.gov NCT02590354.

Keywords: HIV; cell-associated HIV RNA; post-treatment control; total HIV DNA; treatment interruption; viral reservoir.

© 2020 The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of the International AIDS Society.

Figures

Figure 1

(a) Overview of stage 1 and 2 of the study. Timepoints at which blood was drawn for plasma and PBMC separation are indicated with yellow arrows. ART is restarted when treatment resumption criteria are reached or 48 weeks after treatment interruption. (b) t‐DNA values in copies per million PBMCs for all stage 1 participants. Participants with t‐DNA values >66 copies per million PBMCs are indicated with grey dots (n = 75). Patients with t‐DNA values below 66 copies but US‐RNA values above 10 copies per million PBMCs are indicated with green dots (n = 3). Patients with t‐DNA and US‐RNA values below 66 and 10 copies per million PBMCs respectively are indicated with blue dots (n = 38) and are eligible for stage 2 participation. (c) Flow chart with number of patients screened until number of patients who completed the study. ART, antiretroviral therapy; ATI, analytical treatment interruption; PBMC, peripheral blood mononuclear cell; pVL, plasma viral load; t‐DNA, total HIV‐1 DNA; US‐RNA, cell‐associated HIV‐1 unspliced RNA.

Figure 2

(a) Plasma viral rebound dynamics after ATI until ART restart in 16 selected patients with very small viral reservoir, (b, c, d) dynamics of total and integrated HIV‐1 DNA and LTR HIV‐1 CA‐RNA over time in stage 2 patients. p‐Values are from Friedman Rank Sum tests and post‐hoc Nemenyi test. ART, antiretroviral therapy; ATI, analytical treatment interruption; LTR, long terminal repeat; PBMC, peripheral blood mononuclear cell; PW12: 12 weeks after restart ART; VR, timepoint at viral rebound just before restart ART, W, weeks; W0, timepoint at stop ART.

Figure 3

Additional viral parameters before ATI. (a) Ultra‐sensitive plasma viral load (in HIV‐1 RNA copies/mL). (b) Replication competent fraction (in infectious units per million CD4+ T cells, IUPM). (c, d) Viral release from 15 × 106 PBMCs (c) and 5 × 106 CD4+ T cells (d), either spontaneous or after stimulation with PMA + ionomycin (in log copies/mL). p Values are from Wilcoxon matched‐pairs signed‐rank test. ATI, analytical treatment interruption; PBMC, peripheral blood mononuclear cell.

Figure 4

Maximum likelihood phylogenetic trees of V1‐V3 env sequences from rebound plasma and positive quantitative viral outgrowth assay wells (outgrowth) for participants 4012, 3034 and 1011.