Is HIV-1 viraemia below 20 copies/mL in antiretroviral-treated patients associated with virologic outcome?

Background: We aimed to investigate whether very low-level HIV-1 viraemia (VLLV) <20 copies/mL in HIV-1-infected patients on antiretroviral therapy (ART) whose VL was <20 copies/mL, was associated with a subsequent VL > 20 copies/mL.

Methods: VLLV was defined as VL <20 copies/mL and positive HIV-1-PCR. We compared patients with positive and negative HIV-1-PCRs <20 copies/mL at two time points, T0 and T1, after 21st of January 2016. Factors associated with a VLLV and subsequent VL >20 copies/mL were identified by logistic regression models.

Results: Of 1341 participants at T0, 958 (71.4%) had a negative and 383 patients (28.6%) had positive HIV-RNA PCR signal during VL < 20 copies/mL. The negative relative to the positive signal at T0 was independently associated with dolutegravir (DTG) mono and/or DTG-lamivudine dual therapy (compared to nevirapine), a pre-ART-VL of 1000-9999 copies/mL (compared to ≥100,000 copies/mL), and each additional year of virologic suppression. Having a virolologic outcome at T1 of $\ge$ 20 copies/mL was independently associated with prior positive signal at T0. (OR = 2.291, 95% CI = 1.457-3.601, p value < .001), a past ART interruption, and a change in ART regimen during follow-up. Each additional year of virologic suppression was independently associated with a lower risk for a subsequent VL ≥ 20 copies/mL.

Conclusions: A positive HIV-1 RNA PCR <20 copies/mL at T0, was associated with a subsequent VL ≥ 20 copies/mL at T1. This was not a rare phenomenon among patients with VL <20 copies/mL. In most patients with a positive PCR signal, this was not followed by a clinically relevant HIV-1 viraemia, defined as ≥ 200 copies/mL.