Predicting resistance as indicator for need to switch from first-line antiretroviral therapy among patients with elevated viral loads: development of a risk score algorithm

Efficacy, safety, and tolerability of dolutegravir-based ART regimen in Durban, South Africa: a cohort study

BACKGROUND

Dolutegravir is an integrase strand transfer inhibitor that has been recommended for use in first-line antiretroviral regimens by the World Health Organisation and is currently being rolled out globally. There has been safety concerns with dolutegravir which has caused concern about its use in the general population. Dolutegravir first-line regimens have been used in South Africa since early 2020. Therefore, the aim of the present study was to assess the efficacy, safety, and tolerability of first-line dolutegravir-based antiretrovirals amongst adults living with HIV in Durban, South Africa.

METHODS

This was a mixed-methods study, which comprised a cross-sectional survey and longitudinal retrospective follow-up of medical records. The study was conducted between October 2020 and January 2022. Data were described using descriptive and summary statistics. Bivariate logistic regression was applied to socio-demographic and clinical variables and crude odds ratios with a 95% confidence interval was calculated. Pearson chi-square tests, paired sample T-tests, and cross-tabulations were performed on selected variables.

RESULTS

A total of 461 participants were enrolled in the study. There was a significant change in immunological outcomes (p < 0.001) after dolutegravir initiation. Furthermore, an assessment of laboratory parameters showed that there was a significant decrease in cholesterol (p < 0.001) and increase in creatinine (p < 0.001) levels. Increased weight was shown by 60.7% of the participants but was not associated with age, gender, CD4 counts, and previous antiretroviral usage. The study found that 43.6% of the participants experienced at least one side-effect. A total of 21.6% and 23.2% of the participants experienced neuropsychiatric and central nervous system side-effects, respectively. In the bivariate analyses, only gender was shown to be associated with side-effects, and only 1.7% of the participants discontinued the study due to side-effects.

CONCLUSION

Our results suggest that dolutegravir is effective, safe, and well tolerated in the study population.

Viral Load Status Before Switching to Dolutegravir-Containing Antiretroviral Therapy and Associations With Human Immunodeficiency Virus Treatment Outcomes in Sub-Saharan Africa

BACKGROUND

Dolutegravir is being rolled out globally as part of preferred antiretroviral therapy (ART) regimens, including among treatment-experienced patients. The role of viral load (VL) testing before switching patients already on ART to a dolutegravir-containing regimen is less clear in real-world settings.

METHODS

We included patients from the International epidemiology Databases to Evaluate AIDS consortium who switched from a nevirapine- or efavirenz-containing regimen to one with dolutegravir. We used multivariable cause-specific hazards regression to estimate the association of the most recent VL test in the 12 months before switching with subsequent outcomes.

RESULTS

We included 36 393 patients at 37 sites in 5 countries (Democratic Republic of the Congo, Kenya, Rwanda, Tanzania, Uganda) who switched to dolutegravir from July 2017 through February 2020, with a median follow-up of approximately 11 months. Compared with those who switched with a VL <200 copies/mL, patients without a recent VL test or with a preswitch VL ≥1000 copies/mL had significantly increased hazards of an incident VL ≥1000 copies/mL (adjusted hazard ratio [aHR], 2.89; 95% confidence interval [CI], 1.99-4.19 and aHR, 6.60; 95% CI, 4.36-9.99, respectively) and pulmonary tuberculosis or a World Health Organization clinical stage 4 event (aHR, 4.78; 95% CI, 2.77-8.24 and aHR, 13.97; 95% CI, 6.62-29.50, respectively).

CONCLUSIONS

A VL test before switching to dolutegravir may help identify patients who need additional clinical monitoring and/or adherence support. Further surveillance of patients who switched to dolutegravir with an unknown or unsuppressed VL is needed.

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.

Who Has Yet to Test? A Risk Score for Predicting Never Having Tested for Human Immunodeficiency Virus Among Women and Men in Rural Malawi

BACKGROUND

Human immunodeficiency virus (HIV) status awareness is important for preventing onward HIV transmission, and is one of the Joint United Nations Programme on HIV and AIDS (UNAIDS) 90-90-90 goals. Efforts to scale up HIV testing have generally been successful, but identifying at-risk individuals who have never tested for HIV-a population necessary to reach improved HIV status awareness-remains challenging.

METHODS

Using data from a community-based cohort of people living in rural central Malawi, we identified demographic, socioeconomic, and sexual health correlates of never having tested for HIV. Correlates were assigned values from the logistic regression model to develop a risk score that identified who had never tested for HIV.

RESULTS

Among 1310 ever sexually active participants, 7% of the women and 13% of the men had never tested for HIV. Of those who had tested for HIV, about 30% had tested more than 12 months ago. For women, younger age and poorer sexual health knowledge were correlated with never having tested for HIV, and the c-statistic for the risk score was 0.83. For men, their partner having not tested for HIV, low socioeconomic status, and poor sexual health knowledge were correlated with never testing for HIV (c-statistic, 0.81). Among those with a score of 3 or greater, the sensitivity and specificity for never having tested for HIV were 81% and 77% for women, and 82% and 66% for men, respectively.

CONCLUSIONS

About 10% of participants had never tested for HIV. This risk score could help health professionals to identify never testers to increase HIV status awareness in line with 90-90-90 goals.

HIV-1 drug resistance testing is essential for heavily-treated patients switching from first- to second-line regimens in resource-limited settings: evidence from routine clinical practice in Cameroon

Background

With the phase-out of stavudine (d4T), change to first-line regimens with zidovudine (AZT) or tenofovir (TDF) in resource-limited settings (RLS) might increase risks of cross-resistance to nucleos(t) ide reverse transcriptase inhibitors (NRTI). This would restrict the scope of switching to the World Health Organisation (WHO)-recommended standard second-line combinations (SLC) without HIV drug resistance (HIVDR)-testing in routine clinical practice.

Methods

An observational study was conducted among 101 Cameroonian patients (55.4% male, median [IQR] age 34 [10–41] years) failing first-line antiretroviral therapy (ART) in 2016, and stratified into three groups according to NRTIs exposure: exposure to both thymidine analogues AZT “and” D4T (group-A, n = 55); exposure to both TDF and AZT “or” D4T (group-B, n = 22); exposure solely to D4T (group-C, n = 24). Protease-reverse transcriptase HIVDR was interpreted using the HIVdb penalty scores (≥60: high-resistance; 20–59: intermediate-resistance; < 20: susceptible). The acceptable threshold for potential-efficacy was set at 80%.

Results

The median [IQR] CD4, viral RNA, and time on ART, were respectively 129 [29–466] cells/μl, 71,630 [19,041-368,000] copies/ml, and 4 [2–5] years. Overall HIVDR-level was 89.11% (90/101), with 83.2% harbouring M184 V (high-level 3TC/FTC-resistance) and only 1.98% (2/101) major HIVDR-mutations to ritonavir-boosted protease-inhibitors (PI/r). Thymidine-analogue mutations (TAMs)-1 [T215FY (46.53%), M41 L (22.77%), L210 W (8.91%)], with cross-resistance to AZT and TDF, were higher compared to TAMs-2 [D67N (21.78%), K70R (19.80%), K219QE (18.81%)]. As expected, K65R was related with TDF-exposure: 0% (0/55) in group-A, 22.72% (5/22) group-B, 4.17% (1/24) group-C (p = 0.0013). The potential-efficacy of AZT vs. TDF was respectively 43.64% (24/55) vs. 70.91% (39/55) in group-A (p = 0.0038); 63.64% (14/22) vs. 68.28% (15/22) in group-B (p = 1.0000); and 37.50% (9/24) vs. 83.33% (20/24) in group-C (p = 0.0032). CRF02_AG was the prevailing subtype (63.40%), followed by CRF11.cpx (8.91%), A₁ (7.92%), G (5.94%); without any significant effect of the subtype-distribution on HIVDR (92.2% in CRF02_AG vs. 83.8% in non-AG; p = 0.204).

Conclusion

First-line ART-failure exhibits high-level NRTI-resistance, with potential lower-efficacy of AZT compared to TDF. Significantly, using our 80% efficacy-threshold, only patients without NRTI-substitution on first-line could effectively switch to SLC following the WHO-approach. Patients with multiple NRTI-substitutions (exposed to both thymidine-analogues and TDF) on first-line ART would require HIVDR-testing to select active NRTIs for SLC.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3871-0) contains supplementary material, which is available to authorized users.