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.

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 < 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 < 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.