Rate of genotypic mutations and resistance to antiretroviral drugs in a general hospital

Abstract Objectives The objective is to describe the resistance mutation rate in protease and reverse transcriptase genes and sensitivity to different antiretrovirals in our environment. Methods We performed an observational descriptive study in which we examined the samples provided at the Clinical Immunology Laboratory between April 2004 and April 2009. We analysed both the resistance tests and the sensitivity to different drugs in patients with therapeutic failure using Trugene HIV-1 Genotyping Kits ® . Results We registered samples from 242 patients, 61 of which had no detectable resistance. The most prevalent mutations according to drug families were: for nucleoside analog reverse transcriptase inhibitors T215A/C/D/F/L/N/S/Y (24.10%), M184G/I/V/W (14.66%), M41J/L/R/T/W (11.24%) and K219E/G/H/N/R/T/W (10.24%). The highest levels of resistance corresponded to stavudine and lamivudine/emtricitabine, and tenofovir produced the least resistance in our environment. The non-analogues were K103N/R (23.98%), V179D/E/I/M/T (10.82%), A98E/G/S (10.53%) and K101E/P/Q/R (9.06%). Nevirapine presented greater resistance than efavirenz. Protease inhibitors were L10F/I/V (15.95%), M36I/L (13.81%), A71I/T/V (13.10%) and 154L/S/V (7.38%). The darunavir/ritonavir combination was that which presented the least resistance, and tipranavir/ritonavir and lopinavir/ritonavir the most resistance. Conclusions Antiretroviral resistance and sensitivity to retroviral treatment in our environment was similar to results from other studies in Spain, but differed in the high level of resistance to lamivudine/emtricitabine and lopinavir/ritonavir.