Prevalence and mutation patterns of HIV drug resistance from 2010 to 2011 among ART-failure individuals in the Yunnan Province, China

Emergence of HIV-1 drug resistance mutations among children and adolescents undergoing prolonged antiretroviral therapy in Guangxi

OBJECTIVE

Antiretroviral therapy (ART) has been implemented in Guangxi for a long time, and there are no reports of HIV drug resistance mutation (DRM) among children and adolescents experiencing virologic failure after ART. This study aimed to analyse HIV DRM prevalence, patterns, and influencing factors among children and adolescents experiencing virologic failure after ART in Guangxi.

METHODS

We collected samples from a total of 491 HIV-infected individuals under 18 years old experiencing virologic failure after ART from 14 cities in Guangxi. Sequencing and DRM analysis were performed based on pol region. Multivariate logistic regression was employed to analysis the influencing factors of DRM.

RESULTS

Among these patients, 396 cases were successfully sequenced. Of all, 52.53% exhibited HIV DRM, including NNRTI (48.48%), NRTI (34.85%) and PI (1.01%). NRTI and NNRTI dual-class resistance was prevalent (30.3%). M184V/I and K103N mutations were the common mutations in NRTI and NNRTI, respectively. Male sex (aOR = 2.1, 95% CI: 1.26-3.50), CRF01_AE subtype (OR = 2.50, 95% CI: 1.02-5.88), the primary regimen 3TC+AZT+NVP (OR = 10.00, 95% CI: 5.00-25.00), low pretreatment CD4+ T lymphocytes (<200 cells/mm³) (OR = 1.85, 95% CI: 1.00-3.45), and high viral load (>1000 copies/mL) (OR = 4.90, 95% CI: 1.03-23.39) showed higher risk of DRM.

CONCLUSION

HIV DRM is pervasive among children and adolescents experiencing virologic failure in Guangxi. Timely HIV DRM monitoring is crucial to mitigate major mutation accumulation and inform effective treatment strategies.

Drug resistance and influencing factors in HIV-1-infected individuals under antiretroviral therapy in Guangxi, China

OBJECTIVES

To assess the profiles and determinants of drug resistance in HIV-1-infected individuals undergoing ART in Guangxi.

METHODS

Samples and data were collected from HIV-1-infected individuals experiencing virological failure post-ART from 14 cities in Guangxi. Sequencing of the HIV-1 pol gene was conducted, followed by analysis for drug resistance mutations using the Stanford University HIV Drug Resistance Database. Logistic regression was employed to identify potential risk factors associated with both HIV drug resistance and mortality.

RESULTS

A total of 8963 individuals with pol sequences were included in this study. The overall prevalence of HIV-1 drug resistance (HIVDR) was 42.43% (3808/8963), showing a decrease from 59.62% to 41.40% from 2016 to 2023. Factors such as being aged ≥50 years, male, Han nationality, lower education levels, occupations including workers, peasants and children, AIDS, pre-treatment CD4 T cell counts <200 cells/mm3, infection with CRF01_AE and CRF55_01B subtypes, and ART regimen lamivudine/zidovudine/nevirapine were associated with higher susceptibility to HIVDR. The common mutations were M184V (17.38%) and K103N (22.14%). Additionally, the prevalence of M184V, S68G, M41L and G190A were different between the Han and Zhuang populations. Factors including age, gender, ethnicity, education level, occupation, infectious route, clinical stage, viral load, subtype, ART regimen and HIVDR showed significant associations with mortality.

CONCLUSIONS

The factors contributing to drug resistance in the HIV-1 ART individuals in Guangxi appear to be notably intricate. Continuous reinforcement of drug resistance surveillance is imperative, accompanied by the optimization of ART regimens to mitigate virological failures effectively.

Drug resistance profiles and influencing factors among HIV-infected children and adolescents receiving long-term ART: a multicentre observational study in China

OBJECTIVES

To analyse the characteristics and determinants of drug resistance mutations (DRMs) in HIV-infected children and adolescents on long-term ART in China.

METHODS

An observational cohort study was conducted in five centres. All participants younger than 15 years at ART initiation were screened, and those identified as having virological failure (VF) with viral load (VL) ≥ 400 copies/mL were included for genotypic resistance testing. Logistic regression analysis was performed and the accumulation of major mutations was analysed in a subgroup of resistant individuals with complete VL results since HIV diagnosis.

RESULTS

Among 562 eligible participants, protease and RT regions were successfully amplified for 93 who failed treatment with a median of 10.0 years ART. Sixty-eight (73.1%) harboured ≥1 major mutations. NRTI, NNRTI and dual-class resistance accounted for 48.4%, 63.4% and 38.7%, respectively. Only 3.2% were resistant to PIs. Age at ART initiation [adjusted OR (aOR) = 0.813, 95% CI 0.690-0.957], subtype B (aOR = 4.378, 95% CI 1.414-13.560) and an initial NNRTI-based regimen (aOR = 3.331, 95% CI 1.180-9.402) were independently associated with DRMs. Among 40 resistant participants with additional VL data, 55.0% had continued VF on a suboptimal regimen and the estimated duration of VF was positively correlated with the total number of major mutations (r = 0.504, P = 0.001).

CONCLUSIONS

The development of DRMs was common in children and adolescents receiving long-term treatment, and continued VF was prevalent in those with resistance. Timely genotypic testing and new child-friendly formulations are therefore urgently required.

Predictive Factors of Detectable Viral Load in HIV-Infected Patients

Despite availability of effective antiretroviral therapy (ART), many HIV patients still have a detectable viral load (VL). Predictive factors of detectable VL are not well documented. This study was done at two large multidisciplinary HIV outpatient clinics at the Centre hospitalier de l'Université de Montréal (CHUM) and the McGill University Health Centre (MUHC). This is a retrospective case-control study of patients treated between 2016 and 2018. Cases had a VL ≥50 copies/mL in 2018. Controls had an undetectable VL from 2016 to 2018. Matching was based on gender and year of HIV diagnosis. Primary objective was to identify predictive factors of detectable VL. Secondary objectives included to identify predictive factors of virologic failure, low persistent viremia, and viral blip. A forward stepwise model selection by the Akaike Information Criterion of the conditional logistic regression was used to identify predictive factors. Two hundred cases were identified and matched with 200 controls. The cohort was mostly male (68.0%) with a median age of 54 years (21-83 years). Among cases, viral blip was the most common type of detectable VL (43.0%). The strong predictive factors for a detectable VL were adherence to ART and seeking health care services. Asylum seekers were less at risk of detectable VL. Adherence to ART was the only strong predictive factor for virologic failure. Three main predictive factors of detectable VL were identified in two ambulatory clinic hospitals in Montreal. Ascertaining these factors will allow for identification of patients more at risk of detectable VL.

Switching to Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide in Adults With HIV and M184V/I Mutation

BACKGROUND

The ability of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) to maintain virologic suppression in participants with M184V and/or M184I resistance mutations from historical genotypic reports when switching from a tenofovir disoproxil fumarate-based or abacavir (ABC)-based regimen was investigated.

SETTING

Phase IIIb, 48-week, open-label, single-arm, multicenter, clinical trial (NCT02616029).

METHODS

Virologically suppressed adults with HIV and documented M184V/I on historical genotypic records switched to E/C/F/TAF from a tenofovir disoproxil fumarate-based or ABC-based regimen. The primary end point was HIV-1 RNA of <50 copies per milliliter at week 12 using pure virologic response (PVR). Secondary end points included HIV-1 RNA of <50 copies per milliliter at weeks 24/48 (PVR) and at weeks 12, 24, and 48 (Food and Drug Administration snapshot algorithm), and change in CD4+ count at weeks 12, 24, and 48.

RESULTS

M184V alone was reported in 82.8% of 64 participants; 9.4% and 7.8% had M184I and M184V/I, respectively, and 43.8% had archived M184V/I (baseline DNA). All (62/62 with available data, 100%, 95% confidence interval 94.2% to 100%) participants maintained PVR at weeks 12, 24, and 48. By Food and Drug Administration snapshot algorithm, one participant had HIV-1 RNA of ≥50 copies per milliliter (week 12); confirmatory HIV-1 RNA was <50 copies per milliliter. No significant changes were observed in CD4+ cell count. Drug-related adverse events (AEs) were reported by 10 (15.6%) participants. Six (9.4%) and 5 (7.8%) participants had grade 3-4 AEs or serious AEs, respectively (none drug related).

CONCLUSIONS

The presence of the resistance mutations M184V/I did not jeopardize the efficacy of switching to E/C/F/TAF in virologically suppressed adults. High rates of virologic suppression were maintained throughout 48 weeks of therapy and treatment was well tolerated.

Prevalence of pretreatment and acquired HIV-1 mutations associated with resistance to lamivudine or rilpivirine: a systematic review

BACKGROUND

Pretreatment and acquired drug resistance mutations (DRMs) can limit antiretroviral therapy effectiveness.

METHODS

We review prevalence of DRMs with resistance to nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), focusing on lamivudine and rilpivirine, from 127 articles with >100,000 individuals with HIV-1 infection.

RESULTS

Estimated global prevalence of pretreatment resistance to any NRTI was 4% and to any NNRTI was 6%. Most prevalent DRMs resistant to lamivudine or rilpivirine were at positions E138 (4%), V179 (1%) and M184 (1%). Estimated acquired DRM prevalence was 58% for any NRTIs and 67% for any NNRTIs, most frequently at positions M184 (58%) and Y181 (21%).

CONCLUSIONS

This review suggests low risk of lamivudine- or rilpivirine-resistant mutations in treatment-naive, HIV-1-infected individuals.

Large Transmission Clusters of HIV-1 Main Genotypes Among HIV-1 Individuals Before Antiretroviral Therapy in the Hebei Province, China

In recent 10 years, the sexual contact transmission has led to the consecutive upsurge of HIV in Hebei. Especially, the risk behaviors such as homosexual contact in Hebei have presented challenges for HIV prevention and treatment efforts. In this study, we found that 98.9% of subjects attributed their HIV-1 infections to sexual contact, and men who have sex with men (MSM) accounted for 77.5%. CRF01_AE (49.6%), CRF07_BC (29.7%), and subtype B (13.0%) were three main genotypes. AE_cluster 1 (73 cases), AE_cluster 2 (62 cases), and 1 large 07_BC cluster (75 cases) were identified, and only closely clustered with MSM sequences from Beijing. Further, all of HIV-1-resistant strains were circulating in transmission clusters. Particularly, 76.5% of subjects resistant to drugs were circulating in above three large transmission clusters associated with MSM from Beijing. Our study proved that the busy movement of MSM between Beijing and Hebei could meet conveniently, which might result in the bidirectional exchange of HIV-1 strains between Beijing and Hebei. As the most frequent genotypes, large transmission clusters associated with CRF01_AE and CRF07_BC have become one of the main factors resulting in the rapid increase of HIV in Hebei. Therefore, the enhanced surveillance for HIV should be planned early among the floating population traveling between Beijing and Hebei. Hebei should construct the cooperative mechanism for HIV prevention and control together with Beijing.

Prevalence of HIV-1 Drug-Resistance Genotypes Among Unique Recombinant Forms from Yunnan Province, China in 2016-2017

To investigate the prevalence and characteristics of drug-resistance genotypes among unique recombinant forms (URFs) in HIV-1 infected people under long-term antiretroviral treatment failure from Yunnan Province. The plasma samples were collected from antiretroviral therapy (ART)-failure experienced individuals from 2016 to 2017 in Yunnan Province, China. The genotyping drug resistance of HIV-1 pol gene fragments was implemented using in-house assay. According to the analysis of RIP and MEGA 7.0, the HIV-1 strains related to URFs were screened for recombinant identification and drug resistance analysis. A total of 130 pol sequences of HIV-1 URF strains were obtained from 1,121 samples. The proportion of HIV-1 URF strains was 11.6% among the ART-failure individuals from 2016 to 2017 in Yunnan. The overall drug-resistance rate of HIV-1 URF strains was 56.9%. Meanwhile, the percentage of protease inhibitors, nucleoside reverse transcriptase inhibitors (NRTIs), and non-nucleoside reverse transcriptase inhibitors (NNRTIs) resistance was 3.8% (5/130), 36.2% (47/130), and 53.8% (70/130), respectively. Mutations such as M184V/I (35.4%) in NRTIs and K103N/R/S/T (25.4%), V179D/E/T/Y (18.9%), G190A/E/R/S (13.8%), and Y181C (9.2%) in NNRTIs were common among the HIV-1 URF strains relative to other mutations. Factors such as male, sexual transmission pathway, and source of the year 2017 were significantly correlated with the development of HIV-1 URF drug resistance. The emergence of the multiple recombinant forms identified in Yunnan indicates active transmission networks of HIV-1 of different HIV-1 subtype/circulating recombinant forms cross-infection in this region. Therefore, it is necessary to further monitor the molecular epidemiology and drug resistance of HIV-1 in Yunnan.

AIDS prevention and control in the Yunnan region by T cell subset assessment

Background

Prior to being spread throughout broader China, multiple human immunodeficiency virus (HIV)-1 genotypes were originally discovered in the Yunnan Province. As the HIV-1 epidemic continues its spread in Yunnan, knowledge of the influence of gender, age, and ethnicity to instances of HIV reservoirs will benefit monitoring the spread of HIV.

Methods

The degree to which T cells are depleted during an HIV infection depends on the levels of immune activation. T-cell subsets were assessed in newly-diagnosed HIV/AIDS patients in Yunnan, and the influence of age, gender, and ethnicity were investigated. Patients that were newly diagnosed with the HIV-infection between the years 2015 and 2018 at the First Affiliated Hospital of Kunming Medical College were selected for this study (N = 408). The lymphocyte levels and T cell subsets were retrospectively measured in whole blood samples by FACS analysis.

Results

The median CD4 count was 224 ± 191 cells/μl. Significantly higher mean frequencies and absolute numbers were observed in CD3⁺, CD3⁺CD4⁺, CD3⁺CD8⁺, CD45⁺, and CD3⁺CD4⁺/CD45⁺ in females compared to males. Han patients showed a higher total number of CD3+T cells and the ratio of CD3⁺ /CD45⁺ cells compared to any other ethnic minority (P < 0.001). The numbers of CD3+ T-cells, CD3+CD8+ T cells, and CD45+ T cells were highest in the age group ≥ 60. Significant differences were observed in the counts of CD3+, CD3+CD8+, and CD45⁺ cells and the ratio of CD3⁺/CD45⁺ and CD3⁺CD4⁺/CD45⁺ cells between the ≤ 29 and 30–59 age groups.

Conclusion

This study has revealed that low levels of CD4⁺ T cells can be observed in newly-diagnosed HIV/AIDS patients in the Yunnan province. It has also been demonstrated that gender, age, and ethnicity have a significant association with the ratio of T-cell subsets that may contribute to virus progression and disease prognosis in individuals belonging to certain subsets of the population. This study has highlighted the importance of HIV/AIDS screening in at-risk populations to ensure timely and adequate clinical management in Yunnan.

Incidence and types of HIV-1 drug resistance mutation among patients failing first-line antiretroviral therapy

OBJECTIVE

This study aims to investigate the prevalence and types of drug resistance mutations among patients failing first-line antiretroviral therapy (ART).

METHODS

Plasma samples from 112 patients with human immunodeficiency virus-1 (HIV-1) were collected for virus RNA extract and gene amplification. The mutations related to drug resistance were detected and the incidence was statistically analyzed, and the drug resistance rate against common drugs was also evaluated.

RESULTS

103 cases were successfully amplified, and the main drug resistance mutations in the reverse transcriptase (RT) region were M184V (50.49%), K103N (28.16%), Y181C (25.24%), and K65R (27.18%), while no drug main resistance mutation was found in the protease (PR) region. The incidence of drug resistance mutations was significantly different among patients with different ages, routes of infection, duration of treatment, initial ART regimens and viral load. The drug resistance rate to the common drugs was assessed, including Efavirenz (EFV, 71.84%), Nevirapine (NVP, 74.76%), Lamivudine (3TC, 66.02%), Zidovudine (AZT, 4.85%), Stavudine (D4T, 16.51%), and Tenofovir (TDF, 21.36%).

CONCLUSION

The drug resistance mutations to NRTIs and NNRTIs are complex and highly prevalent, which was the leading cause of first-line ART failure. This study provides significant theoretical support for developing the second-line and third-line therapeutic schemes.

Baseline Investigation of HIV-1 Primary Drug Resistance Among Newly Diagnosed Treatment-Naïve HIV-1 Individuals in Hebei, China

Human immunodeficiency virus (HIV) primary drug resistance (PDR) has influenced the long-term therapeutic effects of antiretroviral drugs. However, for the overall PDR prevalence in China, no report was found in published articles. In our study, an extensive cross-sectional investigation based on all newly diagnosed treatment-naive HIV-infected individuals was conducted. The overall prevalence of HIV-1 PDR among newly diagnosed treatment-naive HIV-1 individuals was 8.3% (60/720), obviously beyond the warning line (5.0%) set by WHO. The prevalence of PDR to PIs, nucleoside reverse transcriptase inhibitors, and non-nucleoside reverse transcriptase inhibitors was 4.9% (35/720), 0.4% (3/720), and 2.5% (18/720), respectively. Moreover, the occurrence of HIV-1 PDR strains was random among different prefectures. HIV-1 PDR strains were extensively circulating among the sexual contact population inside and outside the Hebei province, especially between neighboring provinces and Hebei. Hebei province has become the moderate level PDR epidemic area. Enhanced surveillance for PDR is necessary among treatment-naïve individuals in Hebei, and we must take effective measures to cut off the spread of HIV PDR strains.

A Machine Learning Approach for Predicting HIV Reverse Transcriptase Mutation Susceptibility of Biologically Active Compounds

HIV resistance emerging against antiretroviral drugs represents a great threat to the continued prolongation of the lifespans of HIV-infected patients. Therefore, methods capable of predicting resistance susceptibility in the development of compounds are in great need. By targeting the major reverse transcription residues Y181, K103, and L100, we used the biological activities of compounds against these enzymes and the wild-type reverse transcriptase to create Naïve Bayes Networks. Through this machine learning approach, we could predict, with high accuracy, whether a compound would be susceptible to a loss of potency due to resistance. Also, we could perfectly predict retrospectively whether compounds would be susceptible to both a K103 mutant RT and a Y181 mutant RT. In the study presented here, our method outperformed a traditional molecular mechanics approach. This method should be of broad interest beyond drug discovery efforts, and serves to expand the utility of machine learning for the prediction of physical, chemical, or biological properties using the vast information available in the literature.

High prevalence of HIV-1 transmitted drug resistance among therapy-naïve Burmese entering travelers at Dehong ports in Yunnan, China

BACKGROUND

The overall success of Human immunodeficiency virus type 1 (HIV-1) antiretroviral therapy (ART) was heavily challenged upon the occurrence of drug resistance. Dehong Prefecture witnessed not only the first report of HIV-1 infection but also the experimental adoption of antiviral treatment in China. The transmission and epidemic of HIV-1 in Dehong is impacted by cross-border activities. The characteristics of HIV-1 drug resistance among therapy-naïve Burmese entering travelers in Yunnan and their speculated origin are still not clarified.

METHODS

Two hundred ninety-eight HIV-1 infected Burmese entering travelers at Dehong ports were recruited between 2003 and 2012. The partial HIV-1 pol gene fragments were amplified and sequenced for the analysis of drug-resistance mutations (DRMs). Phylogenetic analysis on gag-pol gene was conducted to elucidate phylogenetic and evolutionary characteristics of these drug resistant strains.

RESULTS

It was figured out that the occurrence ratio of HIV-1 drug resistance among HIV-1 infected entering travelers from Myanmar was up to 12.8%. The resistant mutations covered several types, including one type of PI mutations (L33F), six types of NRTI mutations and seven types of NNRTI. Close genetic relationship was observed in the phylogenetic analysis on gag-pol gene among the drug resistant strains respectively from Dehong, other Yunnan areas, neighboring provinces (Guangxi) and neighboring countries (Thailand and Myanmar).

CONCLUSIONS

The findings in this study revealed that HIV drug resistant locus is spreading from the population who is receiving drug-resistance treatment to the new infectors, which indicates the urgency of surveillance work on drug resistance among the migrant population with high risks of HIV infection.

Surveillance of Transmitted Drug Resistance in HIV-1-Infected Youths Aged 16 to 25 Years, a Decade After Scale-up of Antiretroviral Therapy in Hebei, China

Sexual exposure has been the predominant route of HIV-1 spread in Hebei Province, China. However, little information is available on HIV-1-transmitted drug resistance (TDR) among HIV-1-infected youths aged 16 to 25 years who are infected with HIV-1 and sexually active. In this study, the overall prevalence of TDR was 6.6% (10/152), a moderate level (5.0%-15.0%) according to World Health Organization Threshold Survey guidelines. However, the prevalence of TDR to protease inhibitors and nonnucleoside reverse transcriptase inhibitors was 4.6% (7/152) and 2.0% (3/152), respectively, which correspond to a low level (<5.0%). All TDR mutations (M46L/I, Y181C, K101E, and G190E) were found only in youths infected with HIV-1 through sexual activity. The prevalence of TDR among heterosexuals (10.0%, 3/30) was higher than that among men who have sex with men (5.8%, 7/120). TDR mutations resided in CRF01_AE (M46I/L and G190E) and subtype B (Y181C and K101E). Our findings will provide useful information on which drug regimens to use in treating the newly infected people with HIV-1.

HIV-1 drug-resistant mutations and related risk factors among HIV-1-positive individuals experiencing treatment failure in Hebei Province, China

Background

To understand HIV-1 drug resistance in 11 prefectures of Hebei Province, China, we implemented a cross-sectional HIV-1 molecular epidemiological survey.

Methods

Blood samples were collected from 122 newly diagnosed drug-naïve HIV-1-positive individuals and 229 antiretroviral therapy (ART)-failure individuals from 11 prefectures in Hebei Province, China. Patient demographic data were obtained via face-to-face interviews using a standardized questionnaire when blood samples were collected. Genotyping of HIV-1 drug resistance (DR) was implemented using an in-house assay.

Results

In this study, the overall prevalence of HIV-1 DR was 35.5%. The prevalence of HIV-1 DR in participants experiencing treatment failure and ART-naïve participants was 51.9 and 5.9%, respectively. Mutations in protease inhibitors, nucleoside reverse transcriptase inhibitors (NRTIs), and non-NRTI (NNRTIs), as well as dual and multiple mutations were extensively seen in participants experiencing treatment failure. The proportions of NNRTI mutations (χ² = 9.689, p = 0.002) and dual mutations in NRTIs and NNRTIs (χ² = 39.958, p < 0.001) in participants experiencing treatment failure were significantly higher than those in ART-naïve participants. The distributions of M184V/I and M41L mutations differed significantly among three main HIV-1 genotypes identified. Viral load, symptoms in the past 3 months, CD4 counts, transmission route, and the duration of ART were found to be associated with HIV-1 DR.

Conclusions

Our results suggest that new prevention and control strategies should be formulated according to the epidemic characteristics of HIV-1-resistant strains in Hebei Province, where antiretroviral drugs are widely used.

Electronic supplementary material

The online version of this article (doi:10.1186/s12981-017-0133-3) contains supplementary material, which is available to authorized users.

[HIV related risky behavioral network and molecular epidemiology of HIV seroconcordant couples in Taizhou municipality of Zhejiang Province]

Obstract: To characterize and analyze risky sexual networks and genetic scales to potential HIV transmission for HIV seroconcordant couples in Taizhou municipality of Zhejiang Province.

METHODS

HIV seroconcordant positive couples were invited as index cases to participate in an egocentric survey on HIV related risky behavior and behavioral network prior to HIV diagnosis during 2008-2011. Within-couple HIV transmission pairs were determined by the combination of both behavioral and phylogenetic analysis.

RESULTS

Totally 27 HIV seroconcordant couples were enrolled in this study. Male spouses were more likely to report having two or more sexual partners in the past years prior to HIV diagnosis than female spouses (88.9% vs. 37.0%). Among 27 couples, 20 couples including 17 couples by male but not female spouses, 3 couples by female but not male spouses reported having two or more sexual partners (i.e., multiple sexual partners) prior to HIV diagnosis; and 7 couples by both spouses reported having multiple sexual partners. Twenty four of 27 sexual networks were determined to be HIV transmission pairs (20) or potential transmission pairs (4), 3 couples were subtyped with discordant HIV subtypes or large genetic distance and thus had different sources of HIV transmissions. In addition, among 27 concordant couples, HIV drug resistance (HIVDR) or primary HIVDR existed in 6 ART-naïve participants in 4 networks; among them, 2 networks were determined to be potential HIVDR transmission couple pairs.

CONCLUSIONS

The HIV strains isolated in HIV infected spouses characterized with diversity and CRF01_AE was the main strain subtype. One of the spouses with risky behavior infected HIV was the main route of transmission to other spouses through unprotected sexual contacts. HIVDR was isolated from some HIV infected individuals, suggesting the risk for HIVDR transmission in married couples. The results provide enhanced evidence for urgent development of tailored prevention strategies, such as couple-based HIV counseling and testing services to reduce HIV secondary transmission.

Genetic Diversity and Drug Resistance Among Antiretroviral Treatment-Failed Individuals from 2010 to 2012 in Honghe, China

The most common antiretroviral treatment (ART) received by individuals infected with HIV-1 in China is the combination therapy, comprised of nucleoside reverse transcriptase inhibitors (NRTIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs). To assess the prevalence of HIV-1 drug resistance and subtypes in Honghe of Yunnan, China, patient plasmas from ART-failed individuals were collected from January 2010 to December 2012. Genotyping was conducted using an in-house assay on patient plasmas. A total of 254 pol sequences were obtained. The prevalence of drug resistance was 47.2% in ART-failed individuals. Of these drug-resistant individuals, 51.7% harbored HIV strains dually resistant to NRTIs and NNRTIs or protease inhibitors (PIs) (34.2% for NNRTIs and 14.2% for NRTIs). Mutations such as M184V, A62V, T69Ins, K103N, Y181C, and G190A were common among the ART-failed individuals. The frequencies of M184V, A62V, and K103N were 20.5%, 11.0%, and 23.6%, respectively. The most common subtypes in Honghe were CRF08_BC (68.50%) and CRF07_BC (12.20%). The subtypes were almost consistent in different time points for one individual. When receiving ART for 6-12 months, the frequency of HIV-1 drug-resistant variants ranked first. This study shows that the high prevalence of HIV drug resistance observed among the ART-failed individuals should be of increasing concern (monitoring of resistance mutations) in ART regions and facilitate developing novel strategies for prevention and control of HIV infection in China.

Different Effects of Nonnucleoside Reverse Transcriptase Inhibitor Resistance Mutations on Cytotoxic T Lymphocyte Recognition between HIV-1 Subtype B and Subtype A/E Infections

The effect of antiretroviral drug resistance mutations on cytotoxic T lymphocyte (CTL) recognition has been analyzed in HIV-1 subtype B infections, but it remains unclear in infections by other HIV-1 subtypes that are epidemic in countries where antiretroviral drugs are not effectively used. We investigated the effect of nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI)-resistance mutations (Y181C, Y181I, and Y181V) on epitope recognition by CTLs specific for 3 different HIV-1 epitopes (HLA-A*02:01-restricted IV10, HLA-B*35:01-restricted NY9, and HLA-C*12:02-restricted KY9) in subtype B and subtype A/E infections and the accumulation of these mutations in treatment-naive Japanese and Vietnamese. These NNRTI-resistance mutations critically affected NY9-specific and KY9-specific T cell responses in the subtype B infections, whereas they showed a different effect on IV10-specific T cell responses among the subtype B-infected individuals. These mutations affected IV10-specific T cell responses but weakly affected NY9-specific T cell responses in the subtype A/E infections. The substitution at position 3 of NY9 epitope which was found in the subtype A/E virus differently influenced the peptide binding to HLA-B*35:01, suggesting that the differences in peptide binding may result in the differences in T cell recognition between the subtype B virus and A/E virus infections. The Y181C mutation was found to be accumulating in treatment-naive Vietnamese infected with the subtype A/E virus. The present study demonstrated different effects of NNRTI-resistance RT181 mutations on CTL responses between the 2 subtype infections. The Y181C mutation may influence HIV-1 control by the CTLs in Vietnam, since this mutation has been accumulating in treatment-naive Vietnamese.

IMPORTANCE

Antiretroviral therapy leads to the emergence of drug-resistant HIV-1, resulting in virological and clinical failures. Though HIV-1-specific CTLs play a critical role in HIV-1 infection, some of drug resistance mutations located in CTL epitopes are known to affect HIV-1-specific CTL responses. Nonnucleoside reverse transcriptase inhibitor (NNRTI)-resistance RT181 mutations are frequently observed in patients treated with NNRTIs. Such drug resistance mutations may have an influence on immune control by HIV-1-specific CTLs, especially in countries where antiretroviral drugs are not effectively used. We here investigated the effect of three NNRTI-resistance RT181 mutations on immune responses by HIV-1-specific CTLs and the recent accumulation of these mutations in treatment-naive Vietnamese infected with HIV-1 subtype A/E virus. RT181 mutations affected CTL recognition in both subtype A/E and B infections, while the RT Y181C mutation has been accumulating in treatment-naive Vietnamese. The results suggest that the Y181C mutation may influence HIV-1 control by CTLs in Vietnam.

In vitro selection of HIV-1 CRF08_BC variants resistant to reverse transcriptase inhibitors

Human immunodeficiency virus type 1 (HIV-1) circulating recombinant form 08_BC (CRF08_BC), carrying the recombinant reverse transcriptase (RT) gene from subtypes B and C, has recently become highly prevalent in Southern China. As the number of patients increases, it is important to characterize the drug resistance mutations of CRF08_BC, especially against widely used antiretrovirals. In this study, clinically isolated virus (2007CNGX-HK), confirmed to be CRF08_BC with its sequence deposited in GenBank (KF312642), was propagated in human peripheral blood mononuclear cells (PBMCs) with increasing concentrations of nevirapine (NVP), efavirenz (EFV), or lamivudine (3TC). Three different resistance patterns led by initial mutations of Y181C, E138G, and Y188C were detected after the selection with NVP. Initial mutations, in combination with other previously reported substitutions (K20R, D67N, V90I, K101R/E, V106I/A, V108I, F116L, E138R, A139V, V189I, G190A, D218E, E203K, H221Y, F227L, N348I, and T369I) or novel mutations (V8I, S134N, C162Y, L228I, Y232H, E396G, and D404N), developed during NVP selection. EFV-associated variations contained two initial mutations (L100I and Y188C) and three other mutations (V106L, F116Y, and A139V). Phenotypic analyses showed that E138R, Y181C, and G190A contributed high-level resistance to NVP, while L100I and V106L significantly reduced virus susceptibility to EFV. Y188C was 20-fold less sensitive to both NVP and EFV. As expected, M184I alone, or with V90I or D67N, decreased 3TC susceptibility by over 1,000-fold. Although the mutation profile obtained in culture may be different from the patients, these results may still provide useful information to monitor and optimize the antiretroviral regimens.

A novel mutation, D404N, in the connection subdomain of reverse transcriptase of HIV-1 CRF08_BC subtype confers cross-resistance to NNRTIs

OBJECTIVES

Growing evidence suggests that mutations in the connection domain of the HIV-1 reverse transcriptase (RT) can contribute to viral resistance to RT inhibitors. This work was designed to determine the effects of a novel mutation, D404N, in the connection subdomain of RT of HIV-1 CRF08_BC subtype on drug resistance, viral replication capacity (RC) and RT activity.

METHODS

Mutation D404N, alone or together with the other reported mutations, was introduced into an HIV-1 CRF08_BC subtype infectious clone by site-directed mutagenesis. Viral susceptibility to nine RT inhibitors, viral RC and the DNA polymerase activity of viral RT of the constructed virus mutants were investigated. A modelling study using the server SWISS-MODEL was conducted to explore the possible structure-related drug resistance mechanism of the mutation D404N.

RESULTS

Single mutations D404N and H221Y conferred low-level resistance to nevirapine, efavirenz, rilpivirine and zidovudine. Double mutations Y181C/D404N and Y181C/H221Y significantly reduced susceptibility to NNRTIs. The most pronounced resistance to NNRTIs was observed with the triple mutation Y181C/D404N/H221Y. Virus containing D404N as the only mutation displayed ∼50% RC compared with the WT virus. The modelling study suggested that the D404N mutation might abolish the hydrogen bonds between residues 404 and K30 in p51 or K431 in p66, leading to impaired RT subunit structure and enhanced drug resistance.

CONCLUSIONS

These results indicate that D404N is a novel NNRTI-associated mutation in the HIV-1 subtype CRF08_BC and provides information valuable for the monitoring of clinical RTI resistance.

HIV virological failure and drug resistance among injecting drug users receiving first-line ART in China

OBJECTIVE

To explore HIV virological failure and drug resistance among injecting drug users (IDUs) receiving first-line antiretroviral treatment (ART) in China.

DESIGN

A series of cross-sectional surveys from 2003 to 2012 from the Chinese National HIV Drug Resistance (HIVDR) Surveillance and Monitoring Network.

SETTING

China.

PARTICIPANTS

Data were analysed by the Chinese National (HIVDR) Surveillance and Monitoring Network from 2003 to 2012. Demographic, ART and laboratory data (CD4+ cell count, viral load and drug resistance) were included. Factors associated with virological failure were identified by logistic regression analysis.

RESULTS

929 of the 8556 individuals in the Chinese HIVDR database were IDUs receiving first-line ART. For these 929 IDUs, the median duration of treatment was 14 months (IQR 6.0-17.8). 193 of the 929 IDUs (20.8%) experienced virological failure (HIV viral load ≥1000 copies/mL). The prevalence of HIVDR among patients with virological failure was 38.9% (68/175). The proportion of patients with drug resistance to non-nucleoside reverse transcriptase inhibitor (NNRTIs), nucleoside reverse transcriptase inhibitor (NRTIs) and protease inhibitors (PIs) was 52.9%, 76.5% and 4.4%, respectively. Factors independently associated with virological failure include: ethnic minorities, junior high school education or less, farmers, self-reported missing doses in the past month, CD4 cell count at survey from 200 to 349 cells/mm(3) or from 0 to 199 cells/mm(3), and residence of Guangxi and Yunnan provinces.

CONCLUSIONS

The proportion of virological failure was high among IDUs receiving first-line ART in China. However, better treatment outcomes were observed in Guangxi and Yunnan, which indicates the importance of ART education and adherence to intervention, especially for patients who are farmers, minorities or have a poor educational background.

HIV multi-drug resistance at first-line antiretroviral failure and subsequent virological response in Asia

Introduction

First-line antiretroviral therapy (ART) failure often results from the development of resistance-associated mutations (RAMs). Three patterns, including thymidine analogue mutations (TAMs), 69 Insertion (69Ins) and the Q151M complex, are associated with resistance to multiple-nucleoside reverse transcriptase inhibitors (NRTIs) and may compromise treatment options for second-line ART.

Methods

We investigated patterns and factors associated with multi-NRTI RAMs at first-line failure in patients from The TREAT Asia Studies to Evaluate Resistance – Monitoring study (TASER-M), and evaluated their impact on virological responses at 12 months after switching to second-line ART. RAMs were compared with the IAS-USA 2013 mutations list. We defined multi-NRTI RAMs as the presence of either Q151M; 69Ins; ≥2 TAMs; or M184V+≥1 TAM. Virological suppression was defined as viral load (VL) <400 copies/ml at 12 months from switch to second-line. Logistic regression was used to analyze (1) factors associated with multi-NRTI RAMs at first-line failure and (2) factors associated with virological suppression after 12 months on second-line.

Results

A total of 105 patients from 10 sites in Thailand, Hong Kong, Indonesia, Malaysia and Philippines were included. There were 97/105 (92%) patients harbouring ≥1 RAMs at first-line failure, 39/105 with multi-NRTI RAMs: six with Q151M; 24 with ≥2 TAMs; and 32 with M184V+≥1 TAM. Factors associated with multi-NRTI RAMs were CD4 ≤200 cells/µL at genotyping (OR=4.43, 95% CI [1.59–12.37], p=0.004) and ART duration >2 years (OR=6.25, 95% CI [2.39–16.36], p<0.001). Among 87/105 patients with available VL at 12 months after switch to second-line ART, virological suppression was achieved in 85%. The median genotypic susceptibility score (GSS) for the second-line regimen was 2.00. Patients with ART adherence ≥95% were more likely to be virologically suppressed (OR=9.33, 95% CI (2.43–35.81), p=0.001). Measures of patient resistance to second-line ART, including the GSS, were not significantly associated with virological outcome.

Conclusions

Multi-NRTI RAMs at first-line failure were associated with low CD4 level and longer duration of ART. With many patients switching to highly susceptible regimens, good adherence was still crucial in achieving virological response. This emphasizes the importance of continued adherence counselling well into second-line therapy.