Circulating plasma microRNA expression profiles associated with virological failure and HIV drug resistance among adults receiving second-line protease inhibitor-based antiretroviral therapy in Zimbabwe

<title>Abstract</title> <p>Background Virological failure (VF) and HIV drug resistance (HIVDR) remain major challenges to antiretroviral therapy (ART). Plasma viral load (VL) cannot distinguish adherence-related failure from HIVDR, while genotypic resistance testing (GRT) is limited by cost. Circulating plasma microRNAs (miRNAs) may provide complementary host-response markers for monitoring HIV treatment outcomes. We evaluated the expression and discriminatory performance of three miRNAs (hsa-miR-146a-5p, hsa-miR-150-5p, hsa-miR-29a-3p) among adults on protease inhibitor-based second-line ART in Zimbabwe. Methods We conducted a multicentre cross-sectional study (January 2023–August 2025) among adults receiving second-line ART for ≥ 12 months. Participants were classified as virologically suppressed (VS; VL &lt; 1 000 copies/mL) or experiencing VF (VL ≥ 1 000 copies/mL). Individuals with VF underwent GRT and were classified as VF without resistance (VF-NR) or with confirmed resistance (VF-R). Plasma miRNA expression was quantified using reverse transcription quantitative PCR. Discriminatory performance was assessed using receiver operating characteristic analysis with bootstrap validation, and independent associations using multivariable logistic regression. Results Among 119 participants (40 VS, 33 VF-NR and 46 VF-R), miR-146a-5p expression increased, whereas miR-150-5p and miR-29a-3p declined progressively from VS to VF-R. The combined panel discriminated VF (AUC = 0.893) better than individual biomarkers (ΔAUC = 0.125, P &lt; 0.001) and showed moderate discrimination of HIVDR (AUC = 0.769). Higher miR-146a-5p expression was associated with increased odds of VF and HIVDR, while higher miR-150-5p expression was associated with reduced odds of both outcomes. Conclusions A circulating plasma miRNA panel showed promising discrimination of VF and moderate discrimination of HIVDR. These findings support further evaluation of host-response miRNA signatures as complementary tools for VF stratification and prioritisation of confirmatory HIVDR testing.</p>