Genotypic correlation of a virologic response to lamivudine, stavudine and nevirapine in patients for whom combination therapy had failed

Background: Resistance is the consequence of mutations that emerge in the viral proteins targeted by antiretroviral agents. Thus, we focused our attention on mutations in HIV-1 reverse transcriptase to define their association with specific NRTIs and NRTI resistance mutations at therapeutic failure. Patients and methods: The study population included 5 Iranian HIV-positive patients referring to Counseling Behavioral Modification Center in Shiraz who received a combination of antiretroviral therapy (lamivudine, stavudine and nevirapine). PBMC DNA was isolated from blood and PCR was performed to produce a 1200 bp amplicon and resolved by electrophoresis on a 0.7% agarose TBE gel, visualized with ethidium bromide. PCR products from HIV-1- infected patients were cloned into pCR2.1TOPO, then sequenced. Finally, sequence data were analyzed. Results: Results showed drug resistance in 2 patients, of whom one had NNRTI resistance mutations (M230G, L234R and K238H) and other had both NRTI (V75M) and NNRTI (F227L) resistance mutations. Conclusion: Confirmation of genetic resistance in HIV-positive patients who show therapy failure can help physicians to change their drug regime in order to achieve better outcome.