Antiretroviral drug-resistant mutations at baseline and at time of failure of antiretroviral therapy in HIV type 1-coinfected TB patients.

There is limited information on the prevalence and pattern of HIV drug-resistant mutations (DRMs) among HIV-1-coinfected tuberculosis (TB) patients before and after antiretroviral treatment. Patients with HIV-1 and TB were recruited into a clinical trial from two different once-daily antiretroviral regimens and followed for a period of 6 months after ART initiation. Patients were treated with standard short-course anti-TB treatment (2EHRZ3/4RH3) and were randomized to receive ddI/3TC with either nevirapine or efavirenz, once daily. Genotypic drug resistance (DR) testing was carried out for the pol gene at baseline and at the time of virological failure. At baseline, major DRMs with respect to NNRTIs (G190GA) and TAMs (T215S and I) were observed in 3 out of 107 patients. Of 15 treatment failures, 14 had more than one major NRTI and NNRTI mutation. V106M was the major NNRTI mutation that emerged in EFZ and Y181C in the NVP group. Among NRTI mutations, M184V was the commonest followed by L74I/V. Primary drug resistance to antiretroviral drugs was low among HIV-1 co-infected TB patients in south India. A once-daily regimen of ddI/3TC/EFZ or NVP results in a specific pattern of NNRTI mutations and negligible thymidine analog mutations (TAMs).