Reverse transcriptase backbone can alter the polymerization and RNase activities of non-nucleoside reverse transcriptase mutants K101E+G190S

Mutation patterns, cross resistance and virological failure among HIV type-1 patients in Alexandria, Egypt

Aim: The main purpose of this cross-sectional study was to detect the prevalence of drug resistance mutations related to nonnucleoside/nucleoside reverse transcriptase inhibitors (NNRTIs/NRTIs) and protease inhibitors (PIs). Patients & methods: Patients (n = 45) with HIV type-1 were recruited, 30 of whom were treatment naive and 15 treatment experienced. A partial pol gene covering the protease/reverse transcriptase (PRRT) region was amplified and then sequenced by the Sanger method. Results & conclusion: The most common NNRTI/NRTI-related mutations were ‘V179I (24%) and K103N (14.3%)’ and ‘M41L and V75M’ (14.3% each). M36I and H69K were the most prevalent PI-related mutations (86% each). The results of the current study serve as an initial crucial step in defining the overall prevalence of HIV type-1 drug resistance in Egypt.

The development of drug resistance mutations K103N Y181C and G190A in long term Nevirapine-containing antiviral therapy

Objective

We built a cohort study of HIV patients taking long-term first-line Antiretroviral Therapy in 2003. In this assay, we focused on the development of primary drug resistance mutations against Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI), K103N, Y181C and G190A.

Method

The cohort study was built in Henan province, China. We used Single Genome Amplification (SGA) to analyze the frequency of K103N, Y181C and G190A in serial plasma samples of three individual patients. We also performed standard genotype HIV drug resistance assay in 204 patients of this cohort study to analyze the frequency of these mutations.

Result

In the SGA sequences, the K103N decreased and vanished, while the frequency of Y181C and G190A increased in individual patient receiving long-term Antiretroviral Therapy (ART). In the sequences of standard genotype HIV drug resistance assay, the frequency of K103N, Y181C and G190A had the similar pattern with that in SGA sequences. Among these patients, the viral suppression were still sufficient after receiving ART for 72 months, and 78.6% (160/204) patients could have their CD4 count over than 200cells/ul.

Conclusion

In some patients, first-line ART had the possibility to provide sufficient treatment effect for over than 72 months, but in long-term treatment, the dominant NNRTI drug resistance mutation K103N could reduced, while the proportion of variants with mutation Y181C or G190A may increased. This result was not similar with that in vitro study, which state that variant with K103N or Y181C had an equal viral fitness with wild type.