Emergence of HIV-1 drug resistance mutations among antiretroviral-naïve HIV-1-infected patients after rapid scaling up of antiretroviral therapy in Thailand

A systematic review and meta-analysis of HIV transmission risk behaviors, genetic variations, and antiretroviral (ARV) resistance in LGBT populations

Background

Currently, human immunodeficiency virus and acquired immunodeficiency syndrome (HIV/AIDS) has become one of the major health problems worldwide, including Indonesia. East Java is one of the provinces in Indonesia with the highest prevalence of HIV infection. One of the causes of HIV infection transmission is lesbian, gay, bisexual, and transgender (LGBT) practice. Furthermore, the treatment using antiretroviral (ARV) drugs in HIV-1 patients can fail due to the presence of HIV drug resistance.

Objective

The aim of this study is to identify the behavior at risk of HIV transmission among LGBT, patterns of genetic variation and antiretroviral (ARV) resistance.

Methods

A systematic review and meta-analysis based on the PRISMA guidelines was conducted. We searched three databases including PubMed, ScienceDirect, and Google scholar for studies investigating the non-heterosexual behavior as risk factor of HIV infection and antiretroviral resistance. Only studies published in English are considered. The adjusted estimates of the risk were carried out using best-adjusted OR with 95% confidence interval (CI) and significant p value < 0.05.

Results

In the quantitative analysis of HIV infection risk factors, a total of 13 studies were included, which investigated non-heterosexual behavior as a potential factor. The studies involved a total of 37,129 participants, comprising 10,449 individuals in the non-heterosexual behavior group (LGBTQ+) and 26,680 individuals in the heterosexual group. The majority of the participants in this study were from the USA, Japan, China, and Brazil, and the main HIV subgenotypes were B and CRF. Additionally, the antiretroviral resistance of HIV patients was examined, involving a total of 3062 individuals, with 1296 individuals in the non-heterosexual behavior group and 1766 individuals in the heterosexual group. Our calculation showed that non-heterosexual behavior was significant as risk factor of HIV infection (OR = 2.17, 95% CI = 1.94-2.43, p < 0.001) and antiretroviral resistance (OR = 1.31, 95% CI = 1.00-1.71, p = 0.05).

Conclusion

This study concludes that non heterosexual behavior is significant risk factor of HIV infection. A quite prevalent of antiretroviral resistance were found among non heterosexual behavior. The main subgenotype of HIV are B and CRF.

Long-term virological and immunological outcomes between HIV-positive individuals with and without pretreatment HIV drug resistance

BACKGROUND

Pretreatment HIV drug resistance (PHDR) has emerged after scaling-up access to antiretroviral therapy (ART). This study aimed to compare long-term virological and immunological outcomes between HIV-positive individuals with and without PHDR.

METHODS

An observational cohort study was conducted in HIV-positive individuals who had a genotypic resistance test performed prior to ART initiation.

RESULTS

Of 335 participants, 39 were in the PHDR group and 296 were in the control group. ART regimen in PHDR group was adjusted at 6-10 weeks after ART initiation when results of baseline genotypic resistance test were available. Proportions of participants with undetectable viral load were significantly lower in PHDR group at 6 and 12 months (46.2% vs 79.4% (p < .001) and 74.4% vs 90.5% (p = .003), respectively). These virological responses became similar between two groups (p > .05) from 18 through 60 months. Mean change of CD4 counts of PHDR group was significantly lower only at 6 months (+59 vs + 81 cells/mm³ (p = .012); these immunological responses were similar between two groups from 12 through 60 months.

CONCLUSION

Early virological response was lower in HIV-positive participants with PHDR compared to participants without PHDR. Subsequent adjustment of ART according to pretreatment genotypic resistance has contributed to the long-term virological and immunological success that is similar to participants without PHDR.

Brief Report: Prevalence Trend of Transmitted Drug Resistance in a Prospective Cohort of Thai People With Acute HIV Infection

BACKGROUND

The greater availability of different antiretroviral therapy regimens in developing countries may influence the emergence of transmitted drug resistance (TDR). People with acute HIV infection (AHI) represent the best opportunity for real-time monitoring of TDR. This study assessed the TDR prevalence trends over time in a Thai cohort of predominantly men who have sex with men (MSM) with AHI.

METHODS

At the time of RV254/SEARCH010 study (NCT00796146) enrollment and before starting ART, HIV genotyping was used to identify mutations in the reverse transcriptase and protease genes. Testing for TDR mutations was obtained by a validated in-house method with TRUGENE assay in a subset. Genotype sequences were analyzed using the Stanford University HIV Drug Resistance Database.

RESULTS

Genotyping was performed for 573 participants with AHI. Their median age was 26 years (interquartile range 22-31), 97.4% were men, and 94.1% were MSM. Overall TDR prevalence was 7.0%, declining from 12.5% in 2009-2010 to 4.8% in 2017-2018. A declining resistance prevalence to nonnucleoside reverse transcriptase inhibitor emerged from 9.4% in 2009-2010 to 3.5% in 2017-2018 and to nucleoside reverse transcriptase inhibitor from 6.3% to 2.1%. Protease inhibitor resistance showed a decreased TDR level from 3.1% in 2009-2010 to 1.4% in 2017-2018.

CONCLUSIONS

We report an encouraging declining trend in TDR prevalence in a Thai cohort of mainly MSM from 2009 to 2018; in 2017-2018, we observed a low TDR prevalence according to the World Health Organization definition.

Switching protease inhibitors to rilpivirine in HIV-positive individuals with complete viral suppression and without prior HIV drug resistance in a resource-limited setting: a randomized controlled trial

Introduction

Prior to the availability of rilpivirine (RPV), patients who could not tolerate efavirenz and nevirapine (NVP) were treated with protease inhibitor (PI)‐based antiretroviral therapy (ART). Dyslipidaemia and other metabolic complications are commonly associated with PI use. This study aimed to compare the efficacy and adverse events between switching from PI‐based to RPV‐based regimen, versus continuing PI‐based regimens in HIV‐positive individuals with complete viral suppression.

Methods

A randomized controlled trial was conducted in HIV‐positive individuals receiving PI‐based regimens with undetectable HIV RNA and without prior HIV drug resistance. Patients were enrolled between July and December 2017 in a university medical centre in Bangkok, Thailand. They were randomized to switch from PIs to RPV (switch group) or continue ritonavir‐boosted PI (control group). Primary endpoint was the proportion of patients with undetectable HIV RNA at 48 weeks. Changes in CD4 cell counts, lipid profiles and adverse events were also analysed.

Results and discussion

A total of 84 patients were enrolled, 42 in each group. Mean age was 47.7 years and 53.6% were males. At 48 weeks, 95.2% of patients in the switch group and 92.9% of control group had maintained undetectable HIV RNA (difference rate 2.4%; 95% CI, −9.6 to 14.7). Means of CD4 cell counts were 611 and 641 cells/mm³ in switch and control groups respectively (p = 0.632). Mean changes in lipid profiles (switch vs. control groups) were: total cholesterol, −12.5 versus + 12.2 (p = 0.024); LDL, −3.4 versus + 6.2 (p = 0.040); HDL, +1.6 versus + 1.9 (p = 0.887); and triglycerides, −82.6 versus − 24.4 mg/dL (p = 0.031). The mean changes of glucose and eGFR were similar (p > 0.05) between the two groups. The mean change of ALT was significantly greater in switch group (18.2 vs. 4.0 U/L, p = 0.017). One patient in switch group had anorexia and elevated ALT at 14 weeks and completely recovered after RPV discontinuation.

Conclusions

Switching PIs to RPV, in patients with complete viral suppression and without prior HIV drug resistance, sustains viral suppression and yields better lipid profiles. This finding supports its use as switching therapy in patients receiving PI‐based regimens due to intolerance to efavirenz and NVP and previous alternatives limited to PI in resource‐limited settings.

HIV-1 integrase strand-transfer inhibitor resistance in southern Taiwan

The use of antiretroviral therapy has reduced rates of mortality and morbidity in patients with human immunodeficiency virus/acquired immune deficiency syndrome(HIV/AIDS). However, transmission of drug-resistant strains poses a challenge to control the spread of HIV-1. Primary resistance to integrase strand-transfer inhibitors (INSTIs) is rare despite their increased use. The prevalence of transmitted drug resistance (TDR) to INSTIs was 0.9% in northern Taiwan. This study was to analyse the prevalence and risk factors of TDR to INSTIs in southern Taiwan. In this study, we enrolled antiretroviral treatment-naïve HIV-1-infected subjects who underwent voluntary counselling and testing from 2013 to 2016 in southern Taiwan. Genotypic drug resistance, coreceptor tropism (CRT) and INSTI resistance were determined. Logistic regression was used to analyse the risk factors for INSTI polymorphic substitution. Sequences were obtained from 184 consecutive individuals, of whom 96.7% were men who have sex with men and 3.3% were heterosexual. Of the patients, 10% (19/183) had hepatitis B and 33.3% (61/183) had syphilis infection. Subtype B HIV-1 strains were found in 96.1% of the patients. Fifteen patients (8.4%, 15/178) harboured nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors or protease inhibitors resistance. CCR-5 coreceptors were used by 71.4% (130/184) of the patients. None of the patients had INSTI resistance-associated mutations, however 16 patients had INSTI polymorphic substitutions, and they were associated with a higher HIV viral load (p = 0.03, OR 2.4, CI 1.1–5.3) and syphilis infection (p = 0.03, OR 3.7, CI 1.1–12.0). In conclusion, no signature INSTI resistance-associated mutations were detected in our cohort. Continued monitoring of TDR to INSTI is needed due to the increased use of INSTIs.

HIV Drug Resistance among Pre-treatment Cases in Thailand: Four Rounds of Surveys during 2006-2013

In Thailand, antiretroviral therapy (ART) was initiated to treat human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) cases using the empirical regimen with no prior genotypic test to determine drug resistance. In order to assess prevalence rate of HIV drug resistance (HIVDR) among pre-treatment cases, four rounds of survey were carried out in ART clinics, including six, eight, 33 and four ART clinics in each round during 2006-2013. For which, HIVDR testing results were available in 310, 350, 797, and 413 cases in four rounds. It was revealed that HIVDR rates among naive cases were 2.0%, 2.8%, 4.0% and 4.8%, while in experienced cases, the rates were 0, 3.3%, 11.4% and 13.9%. The rates among all cases were 1.9%, 2.9%, 4.4% and 5.6%. Resistant drugs with the highest rates among all cases in the survey round 4 were nevirapine (3.6%) and efavirenz (3.1%). The results indicated the need to continue surveillance for pre-treatment HIVDR, and posed challenges to implement activities for protecting efficacy and prolong the use of empirical first-line regimen. A strategy to apply genotyping test, in a cost-effective approach, should be considered to prepare for situation when HIVDR increases beyond a critical level.

High rate of HIV-1 drug resistance in treatment failure patients in Taiwan, 2009-2014

Background

Drug resistance to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PIs) has been associated with loss of viral suppression measured by a rise in HIV-1 RNA levels, a decline in CD4 cell counts, persistence on a failing treatment regimen, and lack of adherence to combination antiretroviral therapy.

Objectives

This study aimed to monitor the prevalence and risk factors associated with drug resistance in Taiwan after failure of first-line therapy.

Materials and methods

Data from the Veterans General Hospital Surveillance and Monitor Network for the period 2009–2014 were analyzed. Plasma samples from patients diagnosed with virologic failure and an HIV-1 RNA viral load >1000 copies/mL were analyzed by the ViroSeq^™ HIV-1 genotyping system for drug susceptibility. Hazard ratios (HRs) for drug resistance were calculated using a Cox proportional hazard model.

Results

From 2009 to 2014, 359 patients were tested for resistance. The median CD4 count and viral load (log) were 214 cells/μL (interquartile range [IQR]: 71–367) and 4.5 (IQR: 3.9–5.0), respectively. Subtype B HIV-1 strains were found in 90% of individuals. The resistance rate to any of the three classes of antiretroviral drugs (NRTI, NNRTI, and PI) was 75.5%. The percentage of NRTI, NNRTI, and PI resistance was 58.6%, 61.4%, and 11.4%, respectively. The risk factors for any class of drug resistance included age ≤35 years (adjusted HR: 2.30, CI: 1.48–3.56; p<0.0001), initial NNRTI-based antiretroviral regimens (adjusted HR: 1.70, CI: 1.10–2.63; p=0.018), and current NNRTI-based antiretroviral regimens when treatment failure occurs (odds ratio: 4.04, CI: 2.47–6.59; p<0.001). There was no association between HIV-1 subtype, viral load, and resistance.

Conclusion

This study demonstrated a high level of resistance to NRTI and NNRTI in patients with virologic failure to first-line antiretroviral therapy despite routine viral load monitoring. Educating younger men who have sex with men to maintain good adherence is crucial, as PI use is associated with lower possibility of drug resistance.

Monitoring HIV Drug Resistance: Early Warning Indicators to Assess Performance of Thailand's Antiretroviral Treatment Program

OBJECTIVE

To describe trends in Thailand's antiretroviral treatment (ART) program performance assessed by HIV drug resistance early warning indicators (EWIs), as recommended by WHO, between 2009 and 2013.

MATERIAL AND METHOD

Seven EWIs were monitored, viral load (VL) testing coverage, VL suppression, retention in ART, lost to follow-up (LTFU), antiretrovirals (ARVs) dispensing practices, on-time pill pick-up, and pharmacy stock-outs. Data from ART adult patients in National Health Security Office Scheme were analyzed except for pharmacy stock-outs, which were reported from hospitals. Aggregated averages were calculated for each EWI. Chi-square for trend was applied to measure significant changes.

RESULTS

By September 2013, 174,284 adults were receiving ART at 929 hospitals. Over time, improvement in VL testing coverage (53.8% in 2009 to 79.8% in 2013) was observed. VL suppression and on-time pill pick up rates were well above 90%. Rates of retention in ART declined from 84.0 to 82.9%, whereas LTFU rates increased from 8.3 to 9.2% (p<0.001). Prescriptions with inappropriate ARVs decreased from 0.32 to 0.10% (p<0.001). Of reporting hospitals, 96.1%, 96.3%, and 96.2% observed no ARVs stock-out between 2011 and 2013.

CONCLUSION

EWI is a useful tool to monitor ART program performance and to identify area where improvement is needed.

Thai national guidelines for the prevention of mother-to-child transmission of human immunodeficiency virus 2017

BACKGROUND

Thailand has made progress in reducing perinatal HIV transmission rates to levels that meet the World Health Organization targets for so-called "elimination" (<2%) of mother-to-child transmission (MTCT).

OBJECTIVES

To highlight the Thailand National Guidelines on HIV/AIDS Treatment Prevention Working Group issued a new version of its National Prevention of MTCT guidelines in March 2017 aimed to reduce MTCT rate to <1% by 2020.

DISCUSSION OF GUIDELINES

The guidelines include recommending initiation of antepartum antiretroviral therapy (ART) containing tenofovir disoproxil fumarate (TDF) plus lamivudine (3TC)/emtricitabine (FTC) plus efavirenz regardless of CD4 cell count as soon as HIV is diagnosed for ART naïve HIV-infected pregnant women. An alternative regimen is TDF or zidovudine (AZT) plus 3TC/FTC plus lopinavir/ritonavir (LPV/r) for HIV-infected pregnant women suspected resistant to non-nucleoside reverse transcriptase inhibitors. Treatment should be started immediately irrespective of gestational age and continued after delivery for life. Raltegravir is recommended in addition to the ART regimen for HIV-infected pregnant women who present late (gestational age (GA) ≥32 weeks) or those who have a viral load (VL) >1000 copies/mL at GA ≥32 weeks. HIV-infected pregnant women who conceive while receiving ART should continue their treatment regimen during pregnancy. HIV-infected pregnant women who present in labor and are not receiving ART should receive single-dose nevirapine immediately along with oral AZT, and continue ART for life. Infants born to HIV-infected mothers are categorized as high or standard risk for MTCT. High MTCT risk is defined as an infant whose mother has a viral load (VL) > 50 copies/mL at GA > 36 weeks or has received ART <12 weeks before delivery, or has poor ART adherence. These infants should be started on AZT plus 3TC plus NVP for 6 weeks after delivery. Infants with standard MTCT risk should receive AZT for 4 weeks. Formula feeding exclusively is recommended for all HIV-exposed infants.

Prevalence of Primary HIV Drug Resistance in Thailand Detected by Short Reverse Transcriptase Genotypic Resistance Assay

BACKGROUND

HIV drug resistance (HIVDR) is the major cause of treatment failure after scaling up of antiretroviral therapy (ART). HIVDR testing prior to ART initiation is not routinely performed in resource-limited settings. We aimed to assess the prevalence of primary HIVDR by short reverse transcriptase (RT) genotypic resistance assay and evaluate of the impact of the mutations on the treatment outcomes.

METHODS

A prospective cohort study was conducted in treatment-naïve HIV-infected patients. Fourteen major mutations of codon 99-191 on the RT gene were selected (K103N, V106A/M, V108I, Q151M, Y181C/I, M184V/I, Y188C/L/H, and G190S/A) at a cost of testing of 35 USD. The association between the presence of primary HIVDR and undetectable HIV RNA (<50 copies/mL) after 6 months of ART was determined.

RESULTS

A total of 265 HIV-infected patients were included, with a median age of 35.2 (range, 16.8-75.2) years; 62.6% were males. The median (interquartile range) CD4 cell count at ART initiation was 216 (77-381) cells/mm3. The overall prevalence of primary HIVDR was 7.9%. The prevalence of each HIVDR mutation were K103N 6.0%, V106I 1.1%, V108I 0.4%, Y181C 2.3%, Y181I 0.7%, Y181V 0.4%, M184V 3.0%, M184I 1.5%, and G190A 2.3%. No associated factor of having primary HIVDR was determined. By multiple stepwise logistic regression, factors associated with undetectable HIV RNA after 6 months of ART were: having M184V/I (odds ratio [OR] 0.11; 95% confidence interval [CI] 0.02-0.62, p = 0.013), condom use (OR 2.38; 95% CI 1.12-5.06, p = 0.024), and adherence per 5% increase (OR 1.16; 95% CI 1.00-1.35, p = 0.044).

CONCLUSIONS

The prevalence of primary HIVDR is approximately 8%; it is associated with detectable HIV RNA at 6 months after ART initiation. Routine "short RT" genotypic resistance assay should be considered in resource-limited settings to maximize treatment outcome.

Sexual risk behaviors among HIV-patients receiving antiretroviral therapy in Southern Thailand: roles of antiretroviral adherence and serostatus disclosure

The objective of this study was to examine the extent of unprotected sex among patients already established in HIV-medical care and their associated factors. Sexually active patients who were receiving antiretroviral therapy (ART) from five public hospitals in Trang province, Southern Thailand, were interviewed. Of 279 studied patients, 37.3% had unprotected sex in the prior 3 months and 27.2% did not disclose their serostatus to sexual partners. The median duration interquartile range (IQR) of using ART was 47 (27-60) months and 26.7% were non-adherent to ART (i.e., taking less than 95% of the prescribed doses). More than one-third had the perception that ART use would protect against HIV transmission even with unprotected sex. About 36.6% reported that they were unaware of their current CD4 counts and nearly one-third did not receive any safe sex counseling at each medical follow-up. After adjustment for potential confounders, non-adherence to ART and HIV-nondisclosure were strongly associated with an increase in the risk of unprotected sex with the adjusted odds ratio (aOR) of 5.03 (95% CI 2.68-9.44) and 3.89 (95% CI 1.57-9.61), respectively. In contrast, the risk for engaging in unprotected sex was less likely among patients having a negative-serostatus partner (aOR = 0.30; 95% CI 0.12-0.75), a longer duration of the use of ART (aOR = 0.98; 95%CI 0.97-0.99) and an unawareness of their current CD4 levels (aOR = 0.54; 95% CI 0.30-0.99). To maximize the benefits from ART, there should be a bigger emphasis on the "positive prevention" program and more efforts are needed to target the population at risk for unprotected sex. Strategies to encourage adherence to ART and for disclosure of serostatus are also required.

Chemokine co-receptor usage in HIV-1-infected treatment-naïve voluntary counselling and testing clients in Southern Taiwan

OBJECTIVE

The goal of this present study was to determine the proportion of CCR5-tropic and CXCR4-tropic viruses and impact of tropism test on clinical presentation, CD4 cell counts, viral load and genotypic drug resistance from drug-naïve, voluntary counselling and testing (VCT) clients in southern Taiwan.

DESIGN

This was a cross-sectional study. Plasma samples were collected from HIV-1-infected patients from January 2013 to December 2013; subjects were recruited from free VCT centres in southern Taiwan.

SETTING

Taiwan.

PARTICIPANTS

Plasma samples from 108 HIV-1-infected, treatment-naïve, VCT clients were analysed. HIV-1 strains were sequenced, genotype resistance was determined by a commercial kit (Viro-seq) and co-receptor tropism (CRT) was predicted by an internet tool geno2pheno[coreceptor], with a 10% false-positive rate as the cut-off. Differences in progression markers, patient characteristics, VCT questionnaires and HIV subtype distribution were evaluated statistically.

RESULTS

All the 108 VCT clients were male with 90% between the ages of 20 and 40 years. Eighty-eight per cent of the patients were men who have sex with men (MSM). The median (IQR) CD4 cell count was 342 cells/µL (221-454) and the viral load was 4.6 log (4.0-5.0). HIV-transmitted drug resistance was found in 9.3% (10/108) of the patients. CRT predictions indicated that 74% of the patients had only R5-tropic strains. CRT was not associated with CD4 cell counts, patient characteristics, VCT questionnaire and transmitted drug resistance. There was a significant difference with regard to viral load at the time of presentation, showing that patients with R5 more often had a higher viral load as compared with those with X4/DM strains (4.6±0.6 log vs 4.33±0.7 log, p=0.036).

CONCLUSIONS

We found that 74% of the VCT clients were infected with R5-tropic virus strains. HIV-transmitted drug resistance was not associated with CRT predictions. Higher viral load at presentation was predictive of R5 co-receptor usage.

High prevalence of transmitted drug resistance in acute HIV-infected Thai men who have sex with men

: As use of antiretroviral therapy in Thailand increases, so does the potential for transmission of drug-resistant HIV. We describe the prevalence of WHO surveillance drug resistance mutations among 120 subjects who underwent genotypic testing during acute HIV infection in Bangkok, Thailand. In this cohort of predominantly men who have sex with men, we observed an overall transmitted drug resistance prevalence of 9.2%, including nucleoside/nucleotide analog reverse transcriptase inhibitor 5.0%, nonnucleoside analog reverse transcriptase inhibitor 3.4%, and protease inhibitor 3.4%. These prevalence estimates are higher than previous reports of transmitted drug resistance in Thailand. Baseline drug resistance testing may be warranted, particularly among men who have sex with men.

MQ, Sukartiningrum SD, Nasronudin, Kameoka M. Appearance of drug resistance-associated mutations in human immunodeficiency virus type 1 protease and reverse transcriptase derived from drug-treated Indonesian patients

Although HIV-1 drug resistance is a major obstacle in Indonesia, information on drug resistance is limited. In this study, the viral subtype and appearance of drug resistance mutations in the HIV-1 protease (PR) and reverse transcriptase (RT) genes were determined among drug-treated, HIV-1-infected patients in Surabaya. HIV-1 patients who received antiretroviral therapy (ART) more than 2 years were randomly recruited regardless of the viral load or ART failure. Fifty-eight HIV-1 PR genes and 53 RT genes were sequenced. CRF01_AE viruses were identified as the predominant strain. Major drug resistance mutations were not detected in the PR genes. In contrast, 37.7% (20/53) of the participants had one or more major drug resistance mutations in the RT genes, predominantly M184V (28.3%), K103N (11.3%), and thymidine analogue mutations (TAMs) (20.8%). The high prevalence of drug resistance mutations in RT genes indicated the necessity of monitoring the effectiveness of ART in Indonesia.

Prevalence and associated factors for HIV-1 transmitted drug resistance in voluntary clients for counseling and testing in Southern Taiwan

BACKGROUND

According to the World Health Organization, HIV-transmitted drug resistance (TDR) is increasing. We analyzed voluntary counseling test data from a hospital in Southern Taiwan to investigate the TDR pattern in Southern Taiwan, the potential relationship between sexual behavior and HIV transmission, and HIV drug-resistant strain transmission.

METHODS

Genotypic resistance assays were performed on treatment-naïve HIV patients recruited from voluntary counseling testing (VCT) in Southern Taiwan from 2007 to 2011. Drug resistance-associated mutations were interpreted with Stanford University HIV Drug Resistance Database HIVdb program. Socio-demographics and sexual activity were recorded from the VCT questionnaire. Logistic regression analysis was used to analyze the risk factors for TDR, and a phylogenetic tree was constructed to elucidate the pattern of HIV drug-resistant strains.

RESULTS

Among the 161 treatment-naïve HIV-infected patients, most were men who reported having sex with men. The overall TDR rate was 10.6%. Patients with a history of sexually transmitted diseases had a 7.8-fold higher risk of becoming infected with genotypic resistant strains.

CONCLUSION

In Southern Taiwan, the HIV TDR rate was 10.6% among those receiving VCT. Our findings suggest that sexual behavior may play an important role in HIV drug-resistant strain transmission.

Virological failure and HIV-1 drug resistance mutations among naive and antiretroviral pre-treated patients entering the ESTHER program of Calmette Hospital in Cambodia

Introduction

In resource limited settings, patients entering an antiretroviral therapy (ART) program comprise ART naive and ART pre-treated patients who may show differential virological outcomes.

Methods

This retrospective study, conducted in 2010–2012 in the HIV clinic of Calmette Hospital located in Phnom Penh (Cambodia) assessed virological failure (VF) rates and patterns of drug resistance of naive and pre-treated patients. Naive and ART pre-treated patients were included when a Viral Load (VL) was performed during the first year of ART for naive subjects or at the first consultation for pre-treated individuals. Patients showing Virological failure (VF) (>1,000 copies/ml) underwent HIV DR genotyping testing. Interpretation of drug resistance mutations was done according to 2013 version 23 ANRS algorithms.

Results

On a total of 209 patients, 164 (78.4%) were naive and 45 (21.5%) were ART pre-treated. Their median initial CD4 counts were 74 cells/mm³ (IQR: 30–194) and 279 cells/mm³ (IQR: 103–455) (p<0.001), respectively. Twenty seven patients (12.9%) exhibited VF (95% CI: 8.6–18.2%), including 10 naive (10/164, 6.0%) and 17 pre-treated (17/45, 37.8%) patients (p<0.001). Among these viremic patients, twenty-two (81.4%) were sequenced in reverse transcriptase and protease coding regions. Overall, 19 (86.3%) harbored ≥1 drug resistance mutations (DRMs) whereas 3 (all belonging to pre-treated patients) harbored wild-types viruses. The most frequent DRMs were M184V (86.3%), K103N (45.5%) and thymidine analog mutations (TAMs) (40.9%). Two (13.3%) pre-treated patients harbored viruses that showed a multi-nucleos(t)ide resistance including Q151M, K65R, E33A/D, E44A/D mutations.

Conclusion

In Cambodia, VF rates were low for naive patients but the emergence of DRMs to NNRTI and 3TC occurred relatively quickly in this subgroup. In pre-treated patients, VF rates were much higher and TAMs were relatively common. HIV genotypic assays before ART initiation and for ART pre-treated patients infection should be considered as well.

Transmitted drug resistance and antiretroviral treatment outcomes in non-subtype B HIV-1-infected patients in South East Asia

BACKGROUND

We compared treatment outcomes of transmitted drug resistance (TDR) in patients on fully or partially sensitive drug regimens.

METHODS

Factors associated with survival and failure were analyzed using Cox proportional hazards and discrete time conditional logistic models.

RESULTS

TDR, found in 60 (4.1%) of 1471 Asian treatment-naive patients, was one of the significant predictors of failure. Patients with TDR to >1 drug in their regimen were >3 times as likely to fail compared to no TDR.

CONCLUSIONS

TDR was associated with failure in the context of non-fully sensitive regimens. Efforts are needed to incorporate resistance testing into national treatment programs.

Update on antiretroviral treatment during primary HIV infection

Primary HIV-1 infection covers a period of around 12 weeks in which the virus disseminates from the initial site of infection into different tissues and organs. In this phase, viremia is very high and transmission of HIV is an important issue. Most guidelines recommend antiretroviral treatment in patients who are symptomatic, although the indication for treatment remains inconclusive in asymptomatic patients. In this article the authors review the main virological and immunological events during this early phase of infection, and discuss the arguments for and against antiretroviral treatment. Recommendations of different guidelines, the issue of the HIV transmission and transmission of resistance to antiretroviral drugs, as well as recently available information opening perspectives for functional cure in patients treated in very early steps of HIV infection are also discussed.

Molecular diversity of HIV-1 and surveillance of transmitted drug resistance variants among treatment Naïve patients, 5 years after active introduction of HAART in Kuala Lumpur, Malaysia

Expansion of antiretroviral treatment programs have led to the growing concern for the development of antiretroviral drug resistance. The aims were to assess the prevalence of drug resistant HIV-1 variants and to identify circulating subtypes among HAART-naïve patients. Plasma specimens from N = 100 HIV+ HAART-naïve adult were collected between March 2008 and August 2010 and viral RNA were extracted for nested PCR and sequenced. PR-RT sequences were protein aligned and checked for transmitted drug resistance mutations. Phylogenetic reconstruction and recombination analysis were performed to determine the genotypes. Based on the WHO consensus guidelines, none of the recruited patients had any transmitted drug resistance mutations. When analyzed against the Stanford guidelines, 35% of patients had at least one reported mutation that may reduce drug susceptibility to PI (24%), NRTI (5%), and NNRTI (14%). The commonly detected mutation that may affect current first line therapy was V179D (3%), which may lead to reduced susceptibility to NNRTI. The predominant circulating HIV-1 genotypes were CRF01_AE (51%) and CRF33_01B (17%). The prevalence of unique recombinant forms (URF) was 7%; five distinct recombinant structures involving CRF01_AE and subtype B' were observed, among them a cluster of three isolates that could form a novel circulating recombinant form (CRF) candidate. Transmitted drug resistance prevalence among HAART-naïve patients was low in this cohort of patients in Kuala Lumpur despite introduction of HAART 5 years ago. Owing to the high genetic diversity, continued molecular surveillance can identify the persistent emergence of HIV-1 URF and novel CRF with significant epidemiological impact.

Surveillance of transmitted HIV drug resistance in antiretroviral-naive patients aged less than 25 years, in Bangkok, Thailand

Emergence of transmitted HIV drug resistance (TDR) is a concern after global scale-up of antiretroviral therapy (ART). World Health Organization had developed threshold survey method for surveillance of TDR in resource-limited countries. ART in Thailand has been scaling up for >10 years. To evaluate the current TDR in Thailand, a cross-sectional study was conducted among antiretroviral-naive HIV-infected patients aged <25 years who newly visited infectious disease clinic in a university hospital, in 2011. HIV genotypic-resistance test was performed. World Health Organization 2009 surveillance drug-resistance mutations were used to define TDR. Of 50 patients, the prevalence of TDR was 4%. Of 2 patients with TDR, 1 had K103N and the other had Y181C mutations. Transmitted HIV drug resistance is emerging in Thailand after a decade of rapid scale-up of ART. Interventions to prevent TDR at the population level are essentially needed in Thailand. Surveillance for TDR in Thailand has to be regularly performed.

High plasma efavirenz concentration and CYP2B6 polymorphisms in Thai HIV-1 infections

  Efavirenz is mainly metabolized by cytochrome P450 2B6 (CYP2B6). This study aimed to examine the frequencies of CYP2B6 and the association between CYP2B6 polymorphisms and plasma efavirenz concentrations in an HIV-1 infected Thai population. Mid-dose plasma efavirenz concentration was determined at 12 weeks following the initiation of an antiretroviral therapy (tenofovir, lamivudine and efavirenz) in 100 Thai adults with HIV-1 infection using high-performance liquid chromatography. Candidate CYP2B6 polymorphisms (c.64C>T, c.499C>G, c.516G>T, c.785A>G, c.1375A>G, c.1459C>T) were conducted by real-time PCR-based allelic discrimination. The most frequent polymorphisms among this cohort were the CYP2B6 c.785A>G and c.516G>T, which had a frequency of 0.36 and 0.32, respectively. From the cases observed, two single nucleotide polymorphisms (SNPs) (c.516G>T and c.785A>G) were significantly associated with high efavirenz plasma levels (p < 0.05). The most frequent haplotypic combinations were *1/*6, *1/*1, *1/*2 and *6/*6 at a frequency of 42.0%, 32.0%, 8.0% and 7.0%, respectively. Increased plasma concentrations of efavirenz were present in individuals with CYP2B6 *6/*6 [7.210 mg/L; interquartile range (IQR), 5.020-9.260] when compared to those with CYP2B6*1/*1 (1.570 mg/L; IQR, 1.295-2.670), p < 0.001. In our study, the impact of SNPs which are correlated with a high level of efavirenz plasma concentrations was found. The genetic configuration of SNPs which are associated with high plasma efavirenz levels may be useful in optimizing the efavirenz dose that is used in HIV-1 infected patients.

HIV-1 drug resistance-associated mutations among antiretroviral-naive Thai patients with chronic HIV-1 infection

Antiretroviral therapy (ART) has increased in resource-limited settings. This study determined the prevalence of HIV-1 drug resistance-associated mutations (DRAMs) among patients with chronic HIV-1 infections and compare DRAMs between CRF01_AE and B subtypes. ART-naive Thai patients who had ART initiation between 2010 and 2011 were enrolled prospectively. Genotypic assays were performed on viral reverse transcriptase and protease genes within 4 weeks before starting ART. DRAMs were assessed using the International AIDS Society-USA 2011 list. A total of 330 patients were included. HIV-1 subtypes included CRF01_AE (73%), B (23.9%), and others (3.1%). Median (IQR) CD4+ was 66 (23-172) cells/mm(3) and median (IQR) HIV-1 RNA was 5.2 (4.6-5.8) log copies/ml. The prevalence of patients with ≥1 DRAMs for any antiretroviral agents was 17.6%. DRAM prevalence was 17% for non-nucleoside reverse transcriptase inhibitors (NNRTIs), 0.6% for NRTIs, and 0.6% for protease inhibitors (PIs). DRAMs to NNRTIs were V106I (7%), V179D (4.2%), V179T (1.8%), E138A (1.5%), V90I (1.2%), K103N (0.9%), Y181C (0.9%), and P225H (0.3%). DRAMs to NRTIs were M184V (0.3%) and T215S (0.3%). The only major DRAM for PIs was M46L (0.6%). Minor DRAMs to PIs including I13V, M36I, H69K, and L89M were observed more frequently in CRF_01 AE. By multivariate analysis, the factors "HIV-1 subtype B" and "low pretreated CD4+ cell count" were associated with a higher rate of DRAMs. HIV-1 DRAMs, especially to NNRTIs, are emerging in a middle-income country after widespread use of NNRTI-based ART. HIV genotypic assays before ART initiation in patients with chronic HIV-1 infection should be considered.

Low-cost ultra-wide genotyping using Roche/454 pyrosequencing for surveillance of HIV drug resistance

Background

Great efforts have been made to increase accessibility of HIV antiretroviral therapy (ART) in low and middle-income countries. The threat of wide-scale emergence of drug resistance could severely hamper ART scale-up efforts. Population-based surveillance of transmitted HIV drug resistance ensures the use of appropriate first-line regimens to maximize efficacy of ART programs where drug options are limited. However, traditional HIV genotyping is extremely expensive, providing a cost barrier to wide-scale and frequent HIV drug resistance surveillance.

Methods/Results

We have developed a low-cost laboratory-scale next-generation sequencing-based genotyping method to monitor drug resistance. We designed primers specifically to amplify protease and reverse transcriptase from Brazilian HIV subtypes and developed a multiplexing scheme using multiplex identifier tags to minimize cost while providing more robust data than traditional genotyping techniques. Using this approach, we characterized drug resistance from plasma in 81 HIV infected individuals collected in São Paulo, Brazil. We describe the complexities of analyzing next-generation sequencing data and present a simplified open-source workflow to analyze drug resistance data. From this data, we identified drug resistance mutations in 20% of treatment naïve individuals in our cohort, which is similar to frequencies identified using traditional genotyping in Brazilian patient samples.

Conclusion

The developed ultra-wide sequencing approach described here allows multiplexing of at least 48 patient samples per sequencing run, 4 times more than the current genotyping method. This method is also 4-fold more sensitive (5% minimal detection frequency vs. 20%) at a cost 3–5× less than the traditional Sanger-based genotyping method. Lastly, by using a benchtop next-generation sequencer (Roche/454 GS Junior), this approach can be more easily implemented in low-resource settings. This data provides proof-of-concept that next-generation HIV drug resistance genotyping is a feasible and low-cost alternative to current genotyping methods and may be particularly beneficial for in-country surveillance of transmitted drug resistance.