HIV-1 integrase resistance in the context of antiretroviral therapy in paediatric patients ‒ Northeast Brazil

INTRODUCTION: Antiretroviral drug resistance poses a challenge to therapy efficacy. Although Integrase Strand Transfer Inhibitors (INSTIs) have a high genetic barrier to resistance, few studies in Brazil have focused on INSTI resistance. This study aimed to assess HIV mutations associated with INSTI resistance in vertically infected children in Maranhão and Pernambuco, Brazil. METHODS: We conducted a retrospective analysis of antiretroviral resistance profiles in paediatric patients with virological failure receiving care through the Brazilian Unified Health System. Data on viral load, CD4+/CD8+ T-cell counts, and medication dispensing were obtained from Ministry of Health databases (SISGENO, SISCEL, and SICLOM). HIV-1 integrase sequences were analysed. Phylogenetic analysis (IQ-TREE) was used to identify subtypes and recombinants. Resistance-associated mutations were determined using the Stanford HIV Drug Resistance Database. RESULTS: Thirty-one paediatric patients (median age = 12-years) were included. Mean CD4+ count was 999 cells/mm³, and median viral load was 19,235 copies/mL. Subtype B and INSTI resistance mutations were detected in 74.5 % and 64.5 % of patients, respectively. High resistance rates to raltegravir (70.9 %) were observed, highlighting the importance of genotypic monitoring. CONCLUSION: A high frequency of INSTI resistance-associated mutations was identified, indicating the need for continued surveillance in this population.