Persistent Low-level HIV-1 RNA Between 20 and 50 Copies/mL in Antiretroviral-treated Patients: Associated Factors and Virological Outcome

Objectives: The aim of our study was to identify factors associated with persistent low-level viraemia (LLV) in HIV-infected patients under suppressive antiretroviral therapy and to assess the virological outcome of these patients.

Methods: LLV was defined as at least two HIV-1 RNA values between 20 and 50 copies/mL during 1 year of follow-up. We compared patients with all values <20 copies/mL (LLV-) and patients with LLV (LLV+). The 'blip ratio' was defined as (number of HIV-1 RNA values >50 copies/mL)/(number of HIV-1 RNA determinations) before study inclusion.

Results: Among the 656 patients included, 5.8% were in group LLV+. CDC stage B/C at study inclusion and a higher blip ratio before the study period were the only factors independently associated with LLV. During the 1 year follow-up, the proportion of patients experiencing virological failure was not different between the LLV- and LLV+ groups, and 40% of patients shifted from LLV+ to LLV- status.

Conclusions: LLV was infrequent in our series and the follow-up did not evidence a higher rate of virological failure than in fully suppressed patients. LLV seems to be a transient phenomenon that might be driven by residual ongoing viral replication and/or viral release and/or accuracy of viral load assay at lower values.