The current DHHS guidelines define low-level viremia (LLV) as a confirmed detectable HIV RNA level of < 200 copies/mL. They consider virologic failure (VF) as “the inability to achieve or maintain suppression to an HIV RNA level of < 200 copies/mL.” Pending further studies and guidelines updates, how to best manage patients with LLV remains unclear.
This study from the U.S.-based HIV Research Network looked at the association between “viral blips” (HIV-RNA of 51-200 copies/mL) and LLV with VF. The study included 2,795 patients who were enrolled into care from 2005-2015 and who had a baseline HIV-1 RNA >200 c/mL. All were either ART-naïve (89%) or ART-experienced (11%) but not currently on treatment. Patients were included who achieved virologic suppression (≤ 50 on two consecutive VLs) but then had two subsequent detectable viral loads following suppression. Viral blips and LLV were categorized separately into three categories: no blips; LLV of 51-200; and VL of 201-500 copies. Cox proportional hazards regression was used to assess the association between rates of viral blips, LLV and VF (two consecutive VL >500).
During the 10 years of this study, 283 patients (10.1%) had virologic failure, 152 (5.4%) experienced LLV of 51-200 and 110 (4%) experienced LLV to 201-500. Both LLV of 51-200 copies as well as LLV of 201-500 copies were associated with virologic failure. However, in a sensitivity analysis of only the ART naïve patients, the association between LLV of 51-200 and virologic failure was not statistically significant.
I believe this study provides some supportive data for our patients with VL > 200 copies/mL. They are at risk of failing their ART regimen and should be followed closely with adherence counseling and more frequent lab monitoring. Although this study found an association between ART failure and LLV, the numbers were not statistically significant. These data maintain support for current DHHS guidelines of accepting a VL of < 200 copies for stable patients – despite most assays reporting levels above 20 to 50 copies/mL. I often find patients need reassurance when their labs show viral blips. Future studies should provide additional guidance regarding the best way to manage patients with LLV in terms of resistance testing and/or changing ART.
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