Antiretroviral drug resistance in HIV-infected patients in Colombia

BackgroundSystematically obtained data on antiretroviral (ARV) resistance in Colombia are lacking. Local estimates of resistance are needed to guide testing, therapy, and policy.MethodsA cross-sectional study was performed in ARV-naïve individuals and in patients with first ARV failure. Genotypic resistance testing was performed using Viro-seq. Predicted success to first- and second-line regimens recommended by the Colombian HIV treatment guidelines was estimated.ResultsOne hundred and three naïve and 77 experienced patients were included. For naïve patients, resistance mutations were detected in 5.8%, with the most common mutations being 103N (n = 5; 4.9%) and 184 V (n = 3; 2.9%). CD4 count <200 cells/mm3 (p = 0.04) and Centers for Disease Control and Prevention (CDC) category C (p = 0.004) were associated with primary resistance. For experienced individuals, regimens were non-nucleoside reverse transcriptase inhibitor (NNRTI)-based in 57.1%, protease inhibitor (PI)-based in 14.3%, boosted PI-based in 26.0%, and nucleoside reverse transcriptase inhibitor (NRTI)-based in 2.6% of the cases. Resistance mutations were found in 66 patients (85.7%) with failure. The most common mutations were 184 V (n = 48; 62.3%), 103N (n = 37; 48.1%), G190A/S (n = 9; 11.7%), and L90 M (n = 9; 11.7%). Twelve percent had thymidine analogue mutations (TAMs) but only 1% had more than 1 TAM. The predicted success of regimens recommended by the Colombian guidelines was 95% for naïve patients and 84% for experienced patients. Genotyping could increase the success rates to 100% and 94%, respectively.ConclusionsThe frequency of primary HIV resistance in Colombia is similar to estimates from other countries in Latin America. CD4 count and CDC category C may allow identification of most of the naïve patients who would benefit from resistance testing. Resistance testing could favorably impact therapy modification in about 5% and 10% of naïve and experienced patients, respectively.