Genotypic resistance testing improves antiretroviral treatment outcomes in a cohort of adolescents in Cameroon: Implications in the dolutegravir‑era

Background: Acquired drug resistance (ADR) is common among adolescents living with perinatal HIV (APHI) in sub-Saharan Africa (SSA). Personalized management has the potential to improve pediatric antiretroviral therapy (ART), even in the presence of long-term treatment and HIV-1 subtype diversity. Objective: We sought to evaluate the effect of HIV-1 mutational profiling on immuno-virological response and ADR among APHI. Methods: A cohort-study was conducted from 2018-2020 among 311 APHI receiving ART in Cameroon. Clinical, immunological and virological responses were measured at enrolment (T1), 6-months (T2) and 12-months (T3). Immunological failure (IF: CD4<250 cells/mm3), VF (viremia≥1000 copies/ml), and ADR were analyzed, with p<0.05 considered significant. Results: Mean age was 15(±3) years; male-female ratio was 1:1; median [IQR] ART-duration was 36[21-81] months. At T1, T2, and T3 respectively, adherence-level was 66.4%, 58.3% and 66.5%; 14 viral clades were found, driven by CRF02_AG (58.6%); ADR-mutations favored increased switch to second-line ART (16.1%, 31.2%, and 41.9%, p<0.0001). From T1-T3 respectively, there were declining rates of IF (25.5%, 18.9%, and 9.83, p<0.0001), VF (39.7%, 39.9%, and 28.2%, p=0.007), and HIVDR (96.4%, 91.7%, and 85.0%, p=0.099). Predictors of ADR were being on first-line ART (p=0.045), high viremia at enrolment (AOR=12.56, p=0.059), and IF (AOR=5.86, p=0.010). Of note, optimized ART guided by mutational profile (AOR=0.05, p=0.002) was protective. Moreover, full Tenofovir+Lamivudine+Dolutegravir efficacy was predicted in 77% and 62% of APHI respectively after first- and second-line failure. Conclusions: Among APHI in this SSA setting, viral mutational profiling prompts the use of optimized Dolutegravir-based ART regimens, leading to improved immuno-virological response and declining ADR burdens. Thus, implementing personalized HIV medicine in this vulnerable population would substantially improve ART response and the achievement of the 95-95-95 goals in these underserved populations

An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. Methods: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. Results: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. Conclusions: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.Peer reviewe

Programme quality indicators of HIV drug resistance among adolescents in urban versus rural settings of the centre region of Cameroon

Background The high rate of mortality among HIV-vertically infected adolescents might be favoured by HIV drug resistance (HIVDR) emergence, which calls for timeous actions in this underserved population. We thus sought to evaluate program quality indicators (PQIs) of HIVDR among HIV-vertically infected adolescents on antiretroviral therapy (ART). Methods A study was conducted in the Centre region of Cameroon among adolescents (10-19 years) receiving ART in two urban (The Mother-Child Centre of the Chantal BIYA Foundation, the National Social Welfare Hospital) and three rural (Mfou District Hospital, Mbalmayo District Hospital and Nkomo Medical Center) health facilities. Following an exhaustive sampling from ART registers, patient medical files and pharmacy records, data was abstracted for seven PQIs: on-time drug pick-up; retention in care; pharmacy stock outs; dispensing practices; viral load coverage; viral suppression and adequate switch to second-line. Performance in PQIs was interpreted following the WHO-recommended thresholds (desirable, fair and/or poor); with p &lt; 0.05 considered significant. Results Among 967 adolescents (888 urban versus 79 rural) registered in the study sites, validated data was available for 633 (554 in urban and 79 in rural). Performance in the urban vs. rural settings was respectively: on-time drug pick-up was significantly poorer in rural (79% vs. 46%, p = 0.00000006); retention in care was fair in urban (80% vs. 72%, p = 0.17); pharmacy stock outs was significantly higher in urban settings (92% vs. 50%, p = 0.004); dispensing practices was desirable (100% vs. 100%, p = 1.000); viral load coverage was desirable only in urban sites (84% vs. 37%, p &lt; 0.0001); viral suppression was poor (33% vs. 53%, p = 0.08); adequate switch to second-line varied (38.1% vs. 100%, p = 0.384). Conclusion Among adolescents on ART in Cameroon, dispensing practices are appropriate, while adherence to ART program and viral load coverage are better in urban settings. However, in both urban and rural settings, pharmacy stock outs, poor viral suppression and inadequate switch to second-line among adolescents require corrective public-health actions to limit HIVDR and to improve transition towards adult care in countries sharing similar programmatic features