Increasing Frequency and Transmission of HIV-1 Non-B Subtypes among Men Who Have Sex with Men in the Swiss HIV Cohort Study

Frequency of genotypic factors possibly associated with cabotegravir/rilpivirine failure in antiretroviral treatment-naïve and -experienced HIV-1- infected population

OBJECTIVES

The long-acting injectable (LAI) cabotegravir (CAB) and rilpivirine (RPV) treatment offers important advantages over oral ART (antiretroviral therapy), however baseline factors possibly contributing to the CAB/RPV treatment failure were identified. The purpose of this study was to describe the frequency of virologic factors previously influencing efficacy of this treatment, namely RPV and CAB resistance-associated mutations (RAMs) and A1/A6 subtype among naïve and treatment-experienced HIV-1-infected patients from Poland.

METHODS

The following datasets of HIV-1 sequences were analysed: 4809 protease and reverse transcriptase (PR/RT) sequences obtained from 4649 Polish Caucasian patients (4122 naive and 687 non-naïve) supplemented with integrase (PR/RT/INT) sequences in 1217 cases (942 naïve and 275 non-naïve). Sub-subtypes A were assigned by phylogenetic methods. Major and minor CAB and RPV RAMs were determined according to the IAS-USA 2019 list, while minor RAMs were additionally defined based on the Stanford database algorithm.

RESULTS

Subtype A1/A6 frequency ranged from 6.11% in ART failing cases with PR/RT sequences only, to 15.92% for the PR/RT/INT treatment-naïve dataset, while RPV RAMs were found in up to 5.89% of treatment-naïve and 14.56% of ART failing cases. Regardless treatment history, only <1% sequences had combination of two factors (RPV RAMs and A1/A6 subtype). Furthermore, CAB RAMs were found in 1.27% of treatment-naïve and 14.54% of experienced patients.

CONCLUSIONS

Despite notable frequency of subtype A1/A6 or CAB/RPV RAMs analysed separately, combination of at least two factors previously associated with failure or this treatment is rare. As subtype A1/A6 becomes more common across real-life cohorts continued subtyping and RAM screening will remain of key importance for LAI treatment implementation. Sequence data from this article have been deposited in GenBank under accession numbers: GU906860, GU906864, GU906871-GU906874, JQ305750-JQ305791, KC409134-KC409222, KM057341-KM057362, KM283892-KM284490, KT340108-KT340205, MZ468643-MZ468894, MZ671788-MZ671823, OP298017-OP302727.

Similar But Different: Integrated Phylogenetic Analysis of Austrian and Swiss HIV-1 Sequences Reveal Differences in Transmission Patterns of the Local HIV-1 Epidemics

OBJECTIVES

Phylogenetic analyses of 2 or more countries allow to detect differences in transmission dynamics of local HIV-1 epidemics beyond differences in demographic characteristics.

METHODS

A maximum-likelihood phylogenetic tree was built using pol -sequences of the Swiss HIV Cohort Study (SHCS) and the Austrian HIV Cohort Study (AHIVCOS), with international background sequences. Three types of phylogenetic cherries (clusters of size 2) were analyzed further: (1) domestic cherries; (2) international cherries; and (3) SHCS/AHIVCOS-cherries. Transmission group and ethnicities observed within the cherries were compared with the respective distribution expected from a random distribution of patients on the phylogeny.

RESULTS

The demographic characteristics of the AHIVCOS (included patients: 3'141) and the SHCS (included patients: 12'902) are very similar. In the AHIVCOS, 36.5% of the patients were in domestic cherries, 8.3% in international cherries, and 7.0% in SHCS/AHIVCOS cherries. Similarly, in the SHCS, 43.0% of the patients were in domestic cherries, 8.2% in international cherries, and 1.7% in SHCS/AHIVCOS cherries. Although international cherries in the SHCS were dominated by heterosexuals with men who have sex with men being underrepresented, the opposite was the case for the AHIVCOS. In both cohorts, cherries with one patient belonging to the transmission group intravenous drug user and the other one non-intravenous drug user were underrepresented.

CONCLUSIONS

In both cohorts, international HIV transmission plays a major role in the local epidemics, mostly driven by men who have sex with men in the AHIVOS, and by heterosexuals in the SHCS, highlighting the importance of international collaborations to understand global HIV transmission links on the way to eliminate HIV.

Transmission Clusters, Predominantly Associated With Men Who Have Sex With Men, Play a Main Role in the Propagation of HIV-1 in Northern Spain (2013–2018)

Viruses of HIV-1-infected individuals whose transmission is related group phylogenetically in transmission clusters (TCs). The study of the phylogenetic relations of these viruses and the factors associated with these individuals is essential to analyze the HIV-1 epidemic. In this study, we examine the role of TCs in the epidemiology of HIV-1 infection in Galicia and the Basque County, two regions of northern Spain. A total of 1,158 HIV-1-infected patients from both regions with new diagnoses (NDs) in 2013–2018 were included in the study. Partial HIV-1 pol sequences were analyzed phylogenetically by approximately maximum-likelihood with FastTree 2. In this analysis, 10,687 additional sequences from samples from HIV-1-infected individuals collected in Spain in 1999–2019 were also included to assign TC membership and to determine TCs’ sizes. TCs were defined as those which included viruses from ≥4 individuals, at least 50% of them Spaniards, and with ≥0.95 Shimodaira-Hasegawa-like node support in the phylogenetic tree. Factors associated to TCs were evaluated using odds ratios (OR) and their 95% CI. Fifty-one percent of NDs grouped in 162 TCs. Male patients (OR: 2.6; 95% CI: 1.5–4.7) and men having sex with men (MSM; OR: 2.1; 95% CI: 1.4–3.2) had higher odds of belonging to a TC compared to female and heterosexual patients, respectively. Individuals from Latin America (OR: 0.3; 95% CI: 0.2–0.4), North Africa (OR: 0.4; 95% CI: 0.2–1.0), and especially Sub-Saharan Africa (OR: 0.02; 95% CI: 0.003–0.2) were inversely associated to belonging to TCs compared to native Spaniards. Our results show that TCs are important components of the HIV-1 epidemics in the two Spanish regions studied, where transmission between MSM is predominant. The majority of migrants were infected with viruses not belonging to TCs that expand in Spain. Molecular epidemiology is essential to identify local peculiarities of HIV-1 propagation. The early detection of TCs and prevention of their expansion, implementing effective control measures, could reduce HIV-1 infections.