Global Comparison of Drug Resistance Mutations After First-Line Antiretroviral Therapy Across Human Immunodeficiency Virus-1 Subtypes

Intrapatient Development of Multi-Class Drug Resistance in an Individual Infected with HIV-1 CRF01_AE

The rapid expansion of access to antiretroviral therapy (ART) has led to the emergence of multi-class drug resistance (MDR) in people living with HIV (PLWH). However, the viral evolutionary dynamics of the development of MDR has not been well documented. For this study, plasma and peripheral blood mononuclear cells (PBMC) were longitudinally collected at different time points from a PLWH who suffered several periods of ART failure. Next generation sequencing (NGS) was used to analyze the distribution and percent of drug resistance mutations in PBMC and plasma. The results showed the gradual replacement of the wild type protease and integrase genotype by protease inhibitors (PI) and integrase strand transfer inhibitor (INSTI) drug resistant mutations when patient’s ART regimen was changed – driving the increase of genetic variability in HIV DNA. Sampling for this study was initiated after the patient was first diagnosed with ART failure, five years after ART treatment was first initiated. By that time, mutants resistant to the reverse transcriptase inhibitor nevirapine (NVP) had already replaced almost 100% of wild type. After the introduction of the protease inhibitor lopinavir/ritonavir (LPV/r) to the patient’s ART, resistant protease inhibitor (PI) mutants developed slowly. After one month, none were found in PMBC DNA; after sixteen months, less than 20% were mutants; and after three years (two months prior to the patient’s death) PI mutants were still under 50%. However, integrase strand transfer inhibitor (INSTI) mutations evolved much more quickly, replacing approximately 75% of the wild genotype in HIV DNA one year after addition of the integrase inhibitor raltegravir to the patient’s ART, and almost 100% after two years. In summary, our dataset provides the first analysis of the distribution and percent of drug resistance mutations in PBMC and plasma during the development of a four-class drug resistant HIV-1 CRF01_AE virion. The study also showed that months before drug resistant mutants could be found in plasma, NGS identified them in HIV DNA, demonstrating that this can be a very effective tool for early detection of the development of drug resistance.

Distribution characteristics of drug resistance mutations of HIV CRF01_AE, CRF07_BC and CRF08_BC from patients under ART in Ganzhou, China

BACKGROUND

Drug resistance mutation (DRM)-associated virological failure has become a critical issue for ART and the elimination of HIV.

OBJECTIVES

To investigate the distribution characteristics of DRMs of HIV CRF01_AE, CRF07_BC and CRF08_BC, the predominant subtypes in China.

METHODS

Patients receiving ART up to 31 August 2020 in Ganzhou in China were recruited. Full-length sequences of the HIV pol gene were amplified from patients with virological failure. DRMs and antiretroviral susceptibility were explored using the Stanford University HIV Drug Resistance Database HIVdb Program.

RESULTS

Overall, 279 of 2204 patients under ART were found to have virological failure. Nine HIV subtypes were identified among 211 sequences that were amplified successfully and CRF08_BC (37.0%), CRF01_AE (26.1%) and CRF07_BC (25.6%) were the most prevalent, with mutation frequencies of 44.9% (35/78), 52.7% (29/55) and 35.2% (19/54), respectively. The most common DRMs of these three subtypes were K103N and M184V, while the mutation frequencies of M41L, D67N, K70R, K101E, V106M, Y181C, K219E, H221Y and N348I were obviously different among subtypes. The resistance levels and frequencies for antiretroviral drugs for these three subtypes were similar and resistances to nevirapine, efavirenz, lamivudine and emtricitabine were the most frequently observed. Compared with CRF01_AE and CRF07_BC, CRF08_BC had higher proportions of DRMs for NRTIs and lower frequencies of resistance to NRTIs and NNRTIs.

CONCLUSIONS

The distribution characteristics of DRMs of HIV CRF01_AE, CRF07_BC and CRF08_BC were inconsistent and should be considered when selecting antiretroviral strategies, developing new drugs and controlling HIV strains containing DRMs.

Characteristics of drug resistance in HIV-1 CRF55_01B from ART-experienced patients in Guangdong, China

BACKGROUND

HIV-1 acquired drug resistance (ADR) has become a critical clinical and public health issue. Recently, HIV-1 CRF55_01B has been found more frequently in the MSM population.

OBJECTIVE

To investigate the characteristics of HIV-1 drug resistance mutations (DRMs) and the extent of changes in drug susceptibility among ART-experienced CRF55_01B-infected adults of Guangdong.

METHODS

ADR was tested for immediately in CRF55_01B-infected patients with virological failure. Demographic and epidemiological information was collected. DRMs and antiretroviral susceptibility were interpreted using the Stanford University HIV Drug Resistance Database HIVdb program.

RESULTS

Overall, 162 (4.78%) CRF55_01B isolates were identified from 2013 to 2018. Among DRMs, M184V (43.83%) was the most frequent NRTI DRM, followed by K65R (23.46%), and V179E (98.77%) was the most frequent NNRTI DRM, followed by K103N (47.53%) and Y181C (14.81%). According to the HIVdb program, 79.01% of the CRF55_01B-infected patients carried mutations conferring low-level or higher drug resistance to any of the three classes of ART drugs. Among PI DRMs, only one mutation affording low-level resistance to nelfinavir was found (0.62%). Among NRTI DRMs, a high proportion of high-level resistance to lamivudine (58.64%) and emtricitabine (58.02%) was found. As regards NNRTIs, more than 75% of patients carried efavirenz and nevirapine DRMs. The percentages of high-level resistance were 70.99%, 63.58%, 22.22%, 17.90% and 4.32% for nevirapine, efavirenz, rilpivirine, doravirine and etravirine, respectively.

CONCLUSIONS

High frequencies of DRMs and resistance were observed among CRF55_01B-infected patients failing ART in Guangdong, and interventions may be considered to minimize ecological contributions to ART.

HIV-1 re-suppression on a first-line regimen despite the presence of phenotypic drug resistance

We have previously reported on HIV-1 infected patients who fail anti-retroviral therapy but manage to re-suppress without a regimen change despite harbouring major drug resistance mutations. Here we explore phenotypic drug resistance in such patients in order to better understand this phenomenon. Patients (n = 71) failing a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen, but who subsequently re-suppressed on the same regimen, were assessed for HIV-1 genotypic drug resistance through Sanger sequencing. A subset (n = 23) of these samples, as well as genotypically matched samples from patients who did not re-suppress (n = 19), were further assessed for phenotypic drug resistance in an in vitro single cycle assay. Half of the patients (n = 36/71, 51%) harboured genotypic drug resistance, with M184V (n = 18/36, 50%) and K103N (n = 16/36, 44%) being the most prevalent mutations. No significant difference in the median time to re-suppression (31–39 weeks) were observed for either group (p = 0.41). However, re-suppressors with mutant virus rebounded significantly earlier than those with wild-type virus (16 vs. 33 weeks; p = 0.014). Similar phenotypic drug resistance profiles were observed between patients who re-suppressed and patients who failed to re-suppress. While most remained susceptible to stavudine (d4T) and zidovudine (AZT), both groups showed a reduced susceptibility to 3TC and NNRTIs. HIV- 1 infected patients on an NNRTI-based regimen can achieve viral re-suppression on the same regimen despite harbouring viruses with genotypic and phenotypic drug resistance. However, re-suppression was less durable in those with resistance, reinforcing the importance of appropriate regimen choices, ongoing viral load monitoring and adherence counselling.

HIV-1 second-line failure and drug resistance at high-level and low-level viremia in Western Kenya

OBJECTIVE

Characterize failure and resistance above and below guidelines-recommended 1000 copies/ml virologic threshold, upon second-line failure.

DESIGN

Cross-sectional study.

METHODS

Kenyan adults on lopinavir/ritonavir-based second-line were enrolled at AMPATH (Academic Model Providing Access to Healthcare). Charts were reviewed for demographic/clinical characteristics and CD4/viral load were obtained. Participants with detectable viral load had a second visit and pol genotyping was attempted in both visits. Accumulated resistance was defined as mutations in the second, not the first visit. Low-level viremia (LLV) was detectable viral load less than 1000 copies/ml. Failure and resistance associations were evaluated using logistic and Poisson regression, Fisher Exact and t-tests.

RESULTS

Of 394 participants (median age 42, 60% women, median 1.9 years on second-line) 48% had detectable viral load; 21% had viral load more than 1000 copies/ml, associated with younger age, tuberculosis treatment, shorter time on second-line, lower CD4count/percentage, longer first-line treatment interruption and pregnancy. In 105 sequences from the first visit (35 with LLV), 79% had resistance (57% dual-class, 7% triple-class; 46% with intermediate-to-high-level resistance to ≥1 future drug option). LLV was associated with more overall and NRTI-associated mutations and with predicted resistance to more next-regimen drugs. In 48 second-visit sequences (after median 55 days; IQR 28-33), 40% accumulated resistance and LLV was associated with more mutation accumulation.

CONCLUSION

High resistance upon second-line failure exists at levels above and below guideline-recommended virologic-failure threshold, impacting future treatment options. Optimization of care should include increased viral load monitoring, resistance testing and third-line ART access, and consideration of lowering the virologic failure threshold, though this demands further investigation.

Antiretroviral resistance, genotypic characterization and origin of Human Immunodeficiency Virus among the infected wives of Intravenous drug users in Manipur

Increasing incidence of drug resistance is ascertained to be the main obstacles in limiting the virus among the human immunodeficiency virus (HIV) infected individuals. This study investigates the drug resistance mutations (DRMs), genetic variants and origin of transmitted drug resistance of HIV-1 among the HIV-1 infected wives of intravenous drug users (IDUs) in Manipur. 44 HIV pol gene sequences were generated from 56 blood samples by viral gene amplification and sequencing. Sequences were then analysed for drug resistance, genetic variants and origin. The result revealed that among the treatment naive cases, 35.7% had Transmitted Drug Resistance Mutations (TDRMs) while among treatment experienced cases, 50% had Acquired Drug Resistant Mutations (ADRMs). These TDRMs and ADRMs conferred resistance to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and/or protease inhibitors (PIs). Majority of the isolated HIV-1 sequences (77.3%) were subtype C while 9.1% was discordant subtype, 6.8% was subtype B, 4.5% was CRF_01AE and 2.3% was URF_BC. TDRM strains were found to be introduced from Myanmar, Vietnam and mainland India. This study also reveals the appearance of CRF_01AE for the first time in Manipur. The finding of this study indicates high prevalence of drug resistant mutations and complex molecular epidemiology in Manipur.

HIV transmission in discordant couples in Africa in the context of antiretroviral therapy availability

OBJECTIVE

The study aims to understand the basis of continued HIV-1 transmission in Zambian and Rwandan HIV-1-discordant couples in the context of antiretroviral therapy (ART).

DESIGN

We identified nine Zambian and seven Rwandan acutely infected, epidemiologically-linked couples from government couples' voluntary counseling and testing (CVCT) clinics where transmitting partners reported being on ART near the time of transmission.

METHODS

We quantified viral load and plasma antiretroviral drug concentrations near the time of transmission and used these as surrogate measures for adherence. We also sequenced the polymerase gene from both donor and recipient partners to determine the presence of drug resistance mutations (DRMs).

RESULTS

In Zambia, all transmitting partners had detectable viral loads, and 8/9 were not on therapeutic antiretroviral regimens. In the remaining couple, despite being on a therapeutic regimen, DRMs were present and transmitted. In Rwanda, although six of seven transmitting partners had detectable viral loads, therapeutic levels of antiretroviral drugs were detected in four of seven, but were accompanied by DRMs. In the remaining three couples, either no antiretrovirals or subtherapeutic regimens were detected.

CONCLUSIONS

A reduction of ART effectiveness in nontrial settings was associated with lack of antiretrovirals in plasma and detectable viral load, and also drug resistance. In Zambia, where CVCT is not widely implemented, inconsistent adherence was high in couples unaware of their HIV discordance. In Rwanda, where CVCT is deployed country-wide, virologic failure was associated with drug resistance and subsequent transmission. Together, these findings suggest that increasing ART availability in resource-limited settings without risk reduction strategies that promote adherence may not be sufficient to control the HIV epidemic in the post-ART era.

Divergent HIV-1 strains (CRF92_C2U and CRF93_cpx) co-circulating in the Democratic Republic of the Congo: Phylogenetic insights on the early evolutionary history of subtype C

Molecular epidemiological studies revealed that the epicenter of the HIV pandemic was Kinshasa, the capital city of the Democratic Republic of the Congo (DRC) in Central Africa. All known subtypes and numerous complex recombinant strains co-circulate in the DRC. Moreover, high intra-subtype diversity has been also documented. During two previous surveys on HIV-1 antiretroviral drug resistance in the DRC, we identified two divergent subtype C lineages in the protease and partial reverse transcriptase gene regions. We sequenced eight near full-length genomes and classified them using bootscanning and likelihood-based phylogenetic analyses. Four strains are more closely related to subtype C although within the range of inter sub-subtype distances. However, these strains also have small unclassified fragments and thus were named CRF92_C2U. Another strain is a unique recombinant of CRF92_C2U with an additional small unclassified fragment and a small divergent subtype A fragment. The three remaining strains represent a complex mosaic named CRF93_cpx. CRF93_cpx have two fragments of divergent subtype C sequences, which are not conventional subtype C nor the above described C2, and multiple divergent subtype A-like fragments. We then inferred the time-scaled evolutionary history of subtype C following a Bayesian approach and a partitioned analysis using major genomic regions. CRF92_C2U and CRF93_cpx had the most recent common ancestor with conventional subtype C around 1932 and 1928, respectively. A Bayesian demographic reconstruction corroborated that the subtype C transition to a faster phase of exponential growth occurred during the 1950s. Our analysis showed considerable differences between the newly discovered early-divergent strains and the conventional subtype C and therefore suggested that this virus has been diverging in humans for several decades before the HIV/M diversity boom in the 1950s.

Antiretroviral resistance following immunological monitoring in a resource-limited setting of western India: A cross-sectional study

BACKGROUND

The free antiretroviral therapy (ART) program in India still relies on the clinico-immunological monitoring for diagnosis of treatment failure. As the nucleoside reverse transcriptase inhibitor (NRTI) backbone is shared in first- and second-line regimens, accumulation of drug resistant mutations (DRMs) can compromise the efficacy of NRTI. This study was undertaken to describe the pattern of HIV DRMs following immunological monitoring and investigate its impact on the cycling of NRTI between first- and second-line ART.

METHODS AND FINDINGS

This cross-sectional study was performed at a state-sponsored ART clinic of Pune city in western India between January and June 2016. Consecutive adults receiving first-line ART with immunological failure (IF) were recruited for plasma viral load (PVL) estimation. Randomly selected 80 participants with PVL >1000 copies/mL underwent HIV drug resistance genotyping. Of these, 75 plasma sample were successfully genotyped. The median CD4 count and duration of ART at the time of failure were 98 (IQR: 61.60-153.50) cells/μL and 4.62 (IQR: 3.17-6.15) years, respectively. The prevalence of NRTI, non-NRTI, and major protease inhibitor resistance mutations were 89.30%, 96%, and 1.33%, respectively. Following first-line failure, sequences from 56.67% of individuals indicated low- to high-level resistance to all available NRTI. The proportion of sequences with ≥2 thymidine analogue mutations (TAMs) and ≥3 TAMs were 62.12% and 39.39%, respectively. An average of 1.98 TAMs per sequence were observed following IF as compared to 0.37 TAMs per sequence following targeted PVL monitoring at 12 months of ART from a prior study; this difference was significant (p<0.001).

CONCLUSION

The option of cycling of NRTI analogues between first- and second-line regimens would no longer be effective if individuals are followed-up by immunological monitoring due to accumulation of mutations. Introduction of routine PVL monitoring is a priority for the long-term sustainability of free ART program in India.

Antiretroviral Resistance After First-Line Antiretroviral Therapy Failure in Diverse HIV-1 Subtypes in the SECOND-LINE Study

We investigate mutations and correlates according to HIV-1 subtype after virological failure (VF) of standard first-line antiretroviral therapy (ART) (non-nucleoside/nucleotide reverse transcriptase inhibitor [NNRTI] +2 nucleoside/nucleotide reverse transcriptase inhibitor [N(t)RTI]). SECOND-LINE study participants were assessed at baseline for HIV-1 subtype, demographics, HIV-1 history, ART exposure, viral load (VL), CD4(+) count, and genotypic ART resistance. We used backward stepwise multivariate regression (MVR) to assess associations between baseline variables and presence of ≥3 N(t)RTI mutations, ≥1 NNRTI mutation, ≥3 thymidine analog-N(t)RTI [ta-N(t)RTI] mutations (TAMs), the K65/K70 mutation, and predicted etravirine (ETV)/rilpivirine (RPV) activity. The inclusion p-value for MVR was p < .2. The exclusion p-value from stepwise elimination was p > .05. Of 541 participants, 491 (91%) had successfully characterized baseline viral isolates. Subtype distribution: B (n = 123, 25%), C (n = 202, 41%), CRF01_AE (n = 109, 22%), G (n = 25, 5%), and CRF02_AG (n = 27, 5%). Baseline CD4(+) 200-394 cells/mm(3) were associated with <3 N(t)RTI mutations (OR = 0.47; 95% CI 0.29-0.77; p = .003), absence of the K65/K70 mutation (OR = 0.43; 95% CI 0.26-0.73; p = .002), and higher ETV sensitivity (OR = 0.52; 95% CI 0.35-0.78; p = .002). Recent tenofovir (TDF) use was associated with K65/K70 mutations (OR = 8.91; 95% CI 5.00-15.85; p < .001). Subtype CRF01_AE was associated with ≥3 N(t)RTI mutations (OR = 2.34; 95% CI 1.31-4.17; p = .004) and higher RPV resistance (OR = 2.13; 95% CI 1.30-3.49; p = .003), and subtype C was associated with <3 TAMs (OR = 0.45; 95% CI 0.21-0.99; p = .015). Subtypes CRF01_AE (OR = 2.46; 95% CI 1.26-4.78; p = .008) and G (OR = 4.77; 95% CI 1.44-15.76; p = .01) were associated with K65/K70 mutations. Higher VL at confirmed first-line VF was associated with ≥3 N(t)RTI mutations (OR = 1.39; 95% CI 1.07-1.78; p = .013) and ≥3 TAMs (OR = 1.62; 95% CI 1.15-2.29; p = .006). The associations of first-line resistance mutations across the HIV-1 subtypes in this study are consistent with knowledge derived from subtype B, with some exceptions. Patterns of resistance after failure of a first-line ta-N(t)RTI regimen support using TDF in N(t)RTI-containing second-line regimens, or using N(t)RTI-sparing regimens.