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

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. We sought to evaluate the effect of HIV-1 mutational profiling on immuno-virological response and ADR among APHI. 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 #x003C;250 cells/mm3), VF (viremia ≥1,000 copies/ml), and ADR were analyzed, with P#x003C;0.05 considered significant. 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#x003C;0.0001). From T1-T3 respectively, there were declining rates of IF (25.5, 18.9, and 9.83%, P#x003C;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. 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.

HIV-1 subtype diversity and immuno-virological outcomes among adolescents failing antiretroviral therapy in Cameroon: A cohort study.

OBJECTIVE: We sought to evaluate the variability of HIV-1 and its effect on immuno-virological response among adolescents living with perinatally acquired HIV (APHI). METHODS: A cohort study was conducted from 2018-2020 among 311 APHI receiving antiretroviral therapy (ART) in Cameroon. Sequencing of protease and reverse transcriptase regions was performed for participants experiencing virological failure, VF, (Plasma viral load, PVL ≥ 1000 RNA copies/ml). HIV-1 subtypes were inferred by phylogeny; immuno-virological responses were monitored at 3-time points (T1-T3). Cox regression modeling was used to estimate adjusted hazard ratios (aHRs) of progression to: CD4 < 250, and PVL > 5log10, adjusted for acquired drug resistance, gender, ART line, adherence, and duration on treatment; p < 0.05 was considered statistically significant. RESULTS: Of the 141 participants in VF enrolled, the male-female ratio was 1:1; mean age was 15 (±3) years; and median [IQR] duration on ART was 51 [46-60] months. In all phases, 17 viral clades were found with a predominant CRF02_AG (58.2%, 59.4%, and 58.3%). From T1-T3 respectively, there was an increasing CD4 count (213 [154-313], 366 [309-469], and 438 [364-569] cells/mm3) and decline log10 PVL (5.23, 4.43, and 4.43), similar across subtypes. Among participants with CRF02_AG infection, duration of treatment was significantly associated with both rates of progression to CD4 < 250, and PVL > 5log10, aHR = 0.02 (0.001-0.52), and aHR = 0.05 (0.01-0.47) respectively. Moreover, four potential new HIV-1 recombinants were identified (CRF02_AG/02D, CRF02_AG/02A1F2, D/CRF02_AG, and AF2/CRF02_AG), indicating a wide viral diversity. CONCLUSION: Among APHI in settings like Cameroon, there is a wide genetic diversity of HIV-1, driven by CRF02_AG and with potential novel clades due to ongoing recombination events. Duration of treatment significantly reduces the risk of disease progression.

Laboratory Based Surveillance of HIV-1 Acquired Drug Resistance in Cameroon: Implications for Use of Tenofovir-Lamivudine-Dolutegravir (TLD) as Second- or Third-Line Regimens.

Increased HIV drug resistance (HIVDR) with antiretroviral therapy (ART) rollout may jeopardize therapeutic options, especially in this era of transition to fixed-dose tenofovir-lamivudine-dolutegravir (TLD). We studied acquired HIVDR (ADR) patterns and describe potentially active drugs after first- and second-line failure in resource-limited settings (RLS) like Cameroon. A laboratory-based study with 759 patients (≥15 years) experiencing virological failure was carried out at the Chantal Biya International Reference Centre (CIRCB), Yaoundé, Cameroon. Socio-demographic, therapeutic and immunovirological data from patient records were analysed according to HIV-1 genotypic profiles. Median (IQR) ART-duration was 63 (50-308) months. Median CD4 and viremia were 153 (IQR:50-308) cells/mm3 and 138,666 (IQR:28,979-533,066) copies/mL, respectively. Overall ADR was high (93.4% first-line; 92.9%-second-line). TDF, potentially active in 35.7% of participants after first-line and 45.1% after second-line, suggested sub-optimal TLD-efficacy in second-line (64.3%) and third-line (54.9%). All PI/r preserved high efficacy after first-line failure while only DRV/r preserved high-level efficacy (87.9%) after second-line failure. In this resource-limited setting (RLS), ADR is high in ART-failing patients. PI/r strategies remain potent backbones for second-line ART, while only DRV/r remains very potent despite second-line failure. Though TLD use would be preferable, blind use for second- and third-line regimens may be sub-optimal (functional monotherapy with dolutegravir) with high risk of further failure, thus suggesting strategies for selective ART switch to TLD in failing patients in RLS.

Pre-Treatment HIV Drug Resistance and Genetic Diversity in Cameroon: Implications for First-Line Regimens.

The efficacy of first-line antiretroviral therapy (ART) may be hampered by the presence of HIV drug resistance (HIVDR). We described HIV-1 pre-treatment drug resistance (PDR) patterns, effect of viral clades on PDR, and programmatic implications on first-line regimens in Cameroon. A sentinel surveillance of PDR was conducted from 2014 to 2019. Sequencing of HIV-1 protease and reverse transcriptase was performed, and HIVDR was interpreted using Stanford HIVdb.v.9.4. In total, 379 sequences were obtained from participants (62% female, mean age 36 ± 10 years). The overall PDR rate was 15.0% [95% CI: 11.8-19.0] nationwide, with significant disparity between regions (p = 0.03). NNRTI PDR was highest (12.4%), of which 7.9% had DRMs to EFV/NVP. Two regions had EFV/NVP PDR above the 10% critical threshold, namely the Far North (15%) and East (10.9%). Eighteen viral strains were identified, predominated by CRF02_AG (65.4%), with no influence of genetic diversity PDR occurrence. TDF-3TC-DTG predictive efficacy was superior (98.4%) to TDF-3TC-EFV (92%), p < 0.0001. The overall high rate of PDR in Cameroon, not substantially affected by the wide HIV-1 genetic diversity, underscores the poor efficacy of EFV/NVP-based first-line ART nationwide, with major implications in two regions of the country. This supports the need for a rapid transition to NNRTI-sparing regimens, with TDF-3TC-DTG having optimal efficacy at the programmatic level.

HIV-1 genotypic profiling ensures effective response to third-line antiretroviral therapy in Cameroon.

In order to limit the emergence of human immunodeficiency virus (HIV) drug resistance in a context of limited antiretroviral options, we sought to evaluate the efficacy of third-line (3L) regimens considering HIV genotypic resistance profile at initiation of 3L in Cameroon. A cohort-study was conducted from January-September 2020 among patients initiating a 3L antiretroviral therapy regimen at the Yaoundé Central Hospital. HIV-1 protease-reverse transcriptase was sequenced at the Chantal Biya international reference center for research on HIV/AIDS prevention and management and results were interpreted using Stanford HIVdbv8.3. Good virological response (viral load < 390 copies/mL) was assessed after 12 months using OPP-ERA platform. Statistical analyses were performed using Epi Info v7.2.2.6, with P < .05 considered statistically significant. Of the 38 patients initiating 3L with an available genotyping (42% female; median age, 49 [39-57] years), median cluster of differentiation type 4 count and viral load were 173 [34-374] cells/µL and 169,322 [30,382-551,826] copies/mL, respectively. At enrollment, all patients harbored resistance to reverse transcriptase inhibitors and 66% (25/38) to protease-inhibitors, although 63% (24/38) were still susceptible to darunavir/ritonavir. Preferred 3L regimen was dolutegravir + darunavir/r + tenofovir + lamivudine (51%) and median duration on 3L was 21 [17-32] months. Interestingly, 82% (31/38) of the participants achieved good virological response on 3L, regardless of genotypic profile at recruitment, variations in 3L regimens (P = .9) and baseline cluster of differentiation type 4 count (P = .3). Despite the high burden of reverse transcriptase inhibitor - and protease inhibitor boosted by ritonavir drug resistance, genotyping-guided 3L regimens is accompanied by virological success in most patients. This high efficacy, most likely due to use of high genetic barrier antiretrovirals, requires continuous adherence support alongside close monitoring for long-term effectiveness in similar programmatic settings.

Evaluation of HIV-1 capsid genetic variability and lenacapavir (GS-6207) drug resistance-associated mutations according to viral clades among drug-naive individuals.

OBJECTIVES: We evaluated the HIV-1 capsid genetic variability and lenacapavir drug resistance-associated mutations (DRMs) among drug-naive individuals across HIV-1 clades. METHODS: A total of 2031 HIV-1 sequences from drug-naive patients were analysed for capsid amino acid modification and the prevalence of lenacapavir DRMs. Amino acid positions with <5% variability were considered as conserved and variability was analysed by HIV-1 clades. RESULTS: Overall, 63% (148/232) of amino acid positions were conserved in the capsid protein. Of note, conservation was consistent in specific binding residues of cellular factors involved in viral replication [CypA (G89, P90), CPSF6 (Q4, N57, N74, A77, K182) and TRIM-NUP153 (R143)], while N183 (12.31%) was the only non-conserved lenacapavir binding residue. The overall prevalence (95% CI) of lenacapavir DRMs was 0.14% (0.05-0.44) (3/2031), with M66I (0.05%) and Q67H (0.05%) observed in subtype C, and T107N (0.05%) observed in CRF01_AE. Moreover, polymorphic mutations M66C (n = 85; 4.18%), Q67K (n = 78; 3.84%), K70R (n = 7; 0.34%), N74R (n = 57; 2.81%) and T107L (n = 82; 4.03%) were observed at lenacapavir resistance-associated positions. CONCLUSIONS: The low level of lenacapavir DRMs (<1%) supports its predicted effectiveness for treatment and prevention, regardless of HIV-1 clades. The established conserved regions hence serve as a hallmark for the surveillance of novel mutations potentially relevant for lenacapavir resistance.

Evaluation of Circulating and Archived HIV-1 Integrase Drug-Resistance Variants among Patients on Third-Line ART in Cameroon: Implications for Dolutegravir-Containing Regimens in Resource-Limited Settings.

To ensure the long-term efficacy of dolutegravir (DTG), we evaluated the genotypic profile in viral reservoirs among patients on third-line (3L) antiretroviral therapy (ART) in Cameroon, according to prior exposure to raltegravir (RAL). A facility-based study was conducted from May through December 2021 among patients on 3L ART from HIV treatment centers in Yaoundé and Douala. Viral load was measured, and genotyping was performed on plasma RNA and proviral DNA. HIV-1 drug resistance mutations were interpreted using HIVdb.v9.1 and phylogeny analysis was performed using MEGA.v7, with P < 0.05 considered significant. Of the 12,093 patients on ART, 53 fully met our inclusion criteria. The median (IQR) age was 51 years (40 to 55 years), and the male/female ratio was 4/5. The median duration on integrase strand-transfer inhibitors (INSTI)-containing regimens was 18 months (12 to 32 months), and 15.09% (8/53) were exposed to RAL. The most administered 3L ART was TDF+3TC+DTG+DRV/r (33.96%, 18/53). Only 5.66% (3/53) had unsuppressed viremia (>1000 copies/mL). Resistance testing in proviral DNA was successful for 18/22 participants and revealed 1/18 patients (5.56%, in the RAL-arm) with archived mutations at major resistance positions (G140R and G163R). Five subtypes were identified, CRF02_AG (12/18), CRF22_01AE (3/18), A1 (1/18), G (1/18), and F2 (1/18). In Cameroon, 3L-experienced patients had a good virological response with a low level of archived mutations in the integrase. This finding underscored the use of DTG-containing ART for heavily treated patients in similar programmatic settings. However, patients with prior exposure to RAL should be closely monitored following a stratified or personalized approach to mitigate risks of INSTI-resistance, alongside pharmacovigilance. IMPORTANCE We described the analysis of the genotypes of the population within third-line antiviral therapy in Cameroon, with a focus on defining the effects of prior raltegravir (RAL) treatment and resistance mutations for current dolutegravir (DTG) treatment. While supporting the current transition to DTG-containing ART in resource-limited settings toward the achievement of the UNAIDS' goal of HIV elimination by 2030, our findings suggested that RAL-exposed patients may need a specific monitoring approach either in a stratified or personalized model of third-line ART to ensure the long-term success of DTG-containing regimens.

Detection of Gag C-terminal mutations among HIV-1 non-B subtypes in a subset of Cameroonian patients.

Response to ritonavir-boosted-protease inhibitors (PI/r)-based regimen is associated with some Gag mutations among HIV-1 B-clade. There is limited data on Gag mutations and their covariation with mutations in protease among HIV-1 non-B-clades at PI/r-based treatment failure. Thus, we characterized Gag mutations present in isolates from HIV-1 infected individuals treated with a PI/r-regimen (n = 143) and compared them with those obtained from individuals not treated with PI/r (ART-naïve [n = 101] or reverse transcriptase inhibitors (RTI) treated [n = 118]). The most frequent HIV-1 subtypes were CRF02_AG (54.69%), A (13.53%), D (6.35%) and G (4.69%). Eighteen Gag mutations showed a significantly higher prevalence in PI/r-treated isolates compared to ART-naïve (p < 0.05): Group 1 (prevalence < 1% in drug-naïve): L449F, D480N, L483Q, Y484P, T487V; group 2 (prevalence 1-5% in drug-naïve): S462L, I479G, I479K, D480E; group 3 (prevalence ≥ 5% in drug-naïve): P453L, E460A, R464G, S465F, V467E, Q474P, I479R, E482G, T487A. Five Gag mutations (L449F, P453L, D480E, S465F, Y484P) positively correlated (Phi ≥ 0.2, p < 0.05) with protease-resistance mutations. At PI/r-failure, no significant difference was observed between patients with and without these associated Gag mutations in term of viremia or CD4 count. This analysis suggests that some Gag mutations show an increased frequency in patients failing PIs among HIV-1 non-B clades.

Archiving of mutations in HIV-1 cellular reservoirs among vertically infected adolescents is contingent with clinical stages and plasma viral load: Evidence from the EDCTP-READY study.

INTRODUCTION: Globally, HIV-related adolescent deaths have increased about 50%, especially for those who are vertically infected. This could be driven by archived drug resistance mutations (DRMs) as children grow up, which might jeopardize antiretroviral therapy (ART). Our objective was to compare HIV-1 genotypic variation between plasma RNA and proviral DNA of vertically infected adolescents (aged 10-19 years) failing ART. METHODS: A comparative study was conducted in 2019 among 296 adolescents with perinatal HIV infection (ALPHI) failing ART in health facilities of the Centre Region of Cameroon. The WHO clinical stage, CD4 count and plasma viral load (PVL) were measured. For those failing ART (PVL ≥ 1000 copies/mL), RNA (plasma) and proviral DNA (buffy coat) were sequenced in the pol gene at Chantal BIYA International Reference Centre (CIRCB), Yaoundé, Cameroon. HIV-1 subtypes and DRMs were interpreted using Stanford HIVdb v.8.8 and MEGA-X. RESULTS: Of the 30% (89/296) failing ART, 81 had both RNA and DNA sequences generated and three were excluded for APOBEC mutations: the mean age was 16 ± 3 years; female-to-male ratio was 3:5; median PVL was 46 856 copies/mL [interquartile range (IQR): 19 898-271 410]; median CD4 count was 264 cells/µL (IQR: 131-574); and 42% were at WHO clinical stage 3/4. Subtype concordance between RNA and DNA viral strains was 100%, with CRF02_AG being predominant (65%) and two potential new recombinants found (A1/G/K; F1/G). Adolescents with DRMs were significantly higher in plasma than in proviral DNA (92% vs. 86%, p < 0.0001). Prevalent DRMs by drug class (RNA vs. DNA respectively) were at position M184 (74% vs. 67%) for nucleoside reverse transcriptase inhibitors (NRTIs), K103 (63% vs. 59%) for non-NRTIs, and V82, L76 and M46 (2% vs. 2%) for protease inhibitors. A total of 35% (27/78) of adolescents had concordant DRM profiles in RNA and DNA, while 27% (21/78) had DRMs only in proviral DNA. The presence of archived DRMs was associated with advanced clinical stage 3/4 (OR = 0.14, p = 0.0003) and PVL < 5 Log (Copies/mL) (OR: 4.88, p = 0.006). CONCLUSIONS: Although plasma RNA remains more sensitive for detecting HIV-1 DRMs, about a quarter of ALPHI experiencing ART failure in an African setting might have archived DRMs in viral reservoirs, indicating clinically occult resistance. Thus, to ensure effective ART success, proviral DNA profiling (alongside RNA genotyping) would provide additional DRMs for adolescents with advanced clinical stages and/or moderate PVL.

High performance of integrase genotyping on diverse HIV-1 clades circulating in Cameroon: toward a successful transition to dolutegravir-based regimens in low and middle-income countries.

A successful transition to dolutegravir-based regimens in low and middle-income countries (LMICs) requires an integrase genotyping assay effective on diverse HIV-1 clades. We herein developed and validated an in-house integrase genotyping protocol on plasma samples from 195 HIV-infected patients in Cameroon. Median [IQR] viremia was 23,574 (518-109,235) copies/mL; 128/195 participants had ≥1000copies/mL (i.e., WHO-threshold for genotypic resistance testing in LMICs). A total of 18 viral clades were detected: 72(51.1%) CRF02_AG, 38(26.9%) pure subtypes and 31(22.0%) other recombinants. Following WHO-threshold (≥1000copies/ml), sequencing performance was 82.81%(106/128). Regarding viremia, performance was 85.00%(68/80) with ≥100,000copies/mL versus 76.67%(23/30) with 10,000 to 99,999copies/mL (P = 0.22); 83.33%(15/18) with 1,000 to 99,999copies/mL (P = 0.55); 73.68%(14/19) with 500 to 999copies/mL (P = 0.19); 50%(13/26) for 200 to 499copies/mL (P = 0.0005) and 36.36%(8/22) for <200copies/mL (P < 0.0001). The developed in-house integrase-genotyping is highly effective on both pure and recombinant viral clades, even at low-level viremia. This performance underscores its usefulness in monitoring integrase-resistance mutations and supporting the scale-up of dolutegravir-based regimens in LMICs.

Dolutegravir-Based Regimen Ensures High Virological Success despite Prior Exposure to Efavirenz-Based First-LINE ART in Cameroon: An Evidence of a Successful Transition Model.

To ensure optimal prescribing practices in the dolutegravir-era in Cameroon, we compared first-line virological response (VR) under tenofovir + lamivudine + dolutegravir (TLD) according to prior exposure to tenofovir + lamivudine + efavirenz (TLE). A facility-based survey was conducted among patients initiating antiretroviral therapy (ART) with TLD (I-TLD) versus those transitioning from TLE to TLD (T-TLD). HIV viral load was performed and unsuppressed participants (VL > 1000 copies/mL) had genotyping performed by Sanger sequencing. Of the 12,093 patients followed, 310 (mean-age: 41 ± 11 years; 52.26% female) complied with study criteria (171 I-TLD vs. 139 T-TLD). The median ART-duration was 14 (12−17) months among I-TLDs versus 28 (24.5−31) months among T-TLDs (15 (11−19) on TLE and 14 (9−15) on TLD), and 83.15% (148/178) were at WHO clinical stages I/II. The viral suppression rate (<1000 copies/mL) was 96.45%, with 97.08% among I-TLDs versus 95.68% among T-TLDs (p = 0.55). VR was similar in I-TLD versus T-TLD at <400 copies/mL (94.15% versus 94.42%) and age, gender, residence, ART-duration, and WHO stages were not associated with VR (p > 0.05). Genotyping was successful for 72.7% (8/11), with no major mutations to integrase inhibitors found. VR is optimal under first-line TLD after 14 months, even among TLE-exposed, thus confirming the effectiveness of transitioning from TLE to TLD in similar settings, supported by strong pharmacological potency and genetic barrier of dolutegravir.

HIV-1 integrase resistance associated mutations and the use of dolutegravir in Sub-Saharan Africa: A systematic review and meta-analysis.

As sub-Saharan Africa (SSA) countries are transitioning to dolutegravir (DTG)-based ART, baseline data are required for optimal monitoring of therapeutic response. In this frame, we sought to generate up-to-date evidence on the use of integrase-strand transfer inhibitors (INSTI) and associated drug resistance mutations (DRMs) within SSA. In this systematic review and meta-analysis, we included randomized and non-randomized trials, cohort-studies, cross-sectional studies, and case-reports published on INSTI or integrase DRMs in SSA. We included studies of patients exposed to DTG, raltegravir (RAL) or elvitegravir (EVG). Primary outcomes were "the rate of virological control (VC:<50copies/ml)" and "the presence of DRMs" on INSTI-based regimens among patients in SSA. We synthesised extracted data using subgroup analysis, and random effect models were used where appropriate. Additional analyses were conducted to assess study heterogeneity. We identified 1,916 articles/citations through database searches, of which 26 were included in the analysis pertaining to 5,444 patients (mean age: 37±13 years), with 67.62% (3681/5444) female. Specifically, 46.15% (12/26) studies focused on DTG, 26.92% (7/26) on RAL, 23.08% (6/26) on both DTG and RAL, and 3.85% (1/26) on EVG. We found an increasing use of DTG overtime (0% before 2018 to 100% in 2021). Median treatment duration under INSTI-based regimens was 12 [9-36] months. Overall, the rate of VC was 88.51% [95%CI: 73.83-97.80] with DTG vs. 82.49% [95%CI: 55.76-99.45] and 96.55% [95%CI: 85.7-100.00] with RAL and EVG, respectively. In univariate analysis, VC with DTG-containing vs. other INSTI-regimens was significantly higher (OR = 1.44 [95%CI: 1.15-1.79], p = 0.0014). Among reported DRMs at failure, the only DTG resistance-mutations were G118R and R263K. In SSA, DTG presents a superiority effect in VC compared to other INSTIs. Nonetheless, the early detection of INSTI-DRMs calls for sentinel surveillance for a successful transition and a sustained efficacy of DTG in SSA. PROSPERO Registration Number: CRD42019122424.

HIV-1 Gag gene mutations, treatment response and drug resistance to protease inhibitors: A systematic review and meta-analysis protocol.

BACKGROUND: Some mutations in the HIV-1 Gag gene are known to confer resistance to ritonavir-boosted protease inhibitors (PI/r), but their clinical implications remain controversial. This review aims at summarizing current knowledge on HIV-1 Gag gene mutations that are selected under PI/r pressure and their distribution according to viral subtypes. MATERIALS AND METHODS: Randomized and non-randomized trials, cohort and cross-sectional studies evaluating HIV-1 Gag gene mutations and protease resistance associated mutations, will all be included. Searches will be conducted (from January 2000 onwards) in PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Latin American and Caribbean Health Sciences Literature (LILAC), Web of Science, African Journals Online, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. Hand searching of the reference lists of relevant reviews and trials will be conducted and we will also look for conference abstracts. Genotypic profiles of both Gag gene and the protease region as well as viral subtypes (especially B vs. non B) will all serve as comparators. Primary outcomes will be the "prevalence of Gag mutations" and the "prevalence of PI/r resistance associated mutations". Secondary outcomes will be the "rate of treatment failure" and the distribution of Gag mutations according to subtypes. Two reviewers will independently screen titles and abstracts, assess the full texts for eligibility, and extract data. If data permits, random effects models will be used where appropriate. This study will be reported according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta Analyses. DISCUSSION: This systematic review will help identify HIV-1 Gag gene mutations associated to PI/r-based regimen according to viral subtypes. Findings of this review will help to better understand the implications of the Gag gene mutations in PI/r treatment failure. This may later justify considerations of Gag-genotyping within HIV drug resistance interpretation algorithms in the clinical management of patients receiving PI/r regimens. SYSTEMATIC REVIEW REGISTRATION: PROSPERO: CRD42019114851.

Baseline integrase drug resistance mutations and conserved regions across HIV-1 clades in Cameroon: implications for transition to dolutegravir in resource-limited settings.

BACKGROUND: Transition to dolutegravir-based regimens in resource-limited settings (RLS) requires prior understanding of HIV-1 integrase variants and conserved regions. Therefore, we evaluated integrase drug resistance mutations (DRMs) and conserved regions amongst integrase strand transfer inhibitor (INSTI)-naive patients harbouring diverse HIV-1 clades in Cameroon. METHODS: A cross-sectional study was conducted amongst 918 INSTI-naive patients from Cameroon (89 ART-naive and 829 ART-experienced patients). HIV-1 sequences were interpreted regarding INSTI-DRMs using the Stanford HIVdb v8.9-1 and the 2019 IAS-USA list. Amino acid positions with <1% variability were considered as highly conserved. Subtyping was performed by phylogeny. RESULTS: Overall prevalence (95% CI) of INSTI-DRMs was 0.8% (0.4-1.7), with 0.0% (0.0-4.0) amongst ART-naive versus 0.9% (0.5-1.9) amongst ART-experienced patients; P = 0.44. Accessory mutations (95% CI) were found in 33.8% (30.9-37.0), with 38.2% (28.1-49.1) amongst ART-naive versus 33.4% (30.4-36.7) amongst ART-experienced patients; P = 0.21. Of 288 HIV-1 integrase amino acid positions, 58.3% were highly conserved across subtypes in the following major regions: V75-G82, E85-P90, H114-G118, K127-W132, E138-G149, Q168-L172, T174-V180, W235-A239 and L241-D253. Wide genetic diversity was found (37 clades), including groups M (92.3%), N (1.4%), O (6.2%) and P (0.1%). Amongst group M, CRF02_AG was predominant (47.4%), with a significantly higher frequency (95% CI) of accessory mutations compared with non-AG [41.4% (36.8-46.0) versus 27.1% (23.3-31.2) respectively; P < 0.001]. CONCLUSIONS: The low baseline of INSTI-DRMs (<1%) in Cameroon suggests effectiveness of dolutegravir-based regimens. In spite of high conservation across clades, the variability of accessory mutations between major circulating strains underscores the need for monitoring the selection of INSTI-DRMs while scaling up dolutegravir-based regimens in RLS.

First case of Dolutegravir and Darunavir/r multi drug-resistant HIV-1 in Cameroon following exposure to Raltegravir: lessons and implications in the era of transition to Dolutegravir-based regimens.

BACKGROUND: Sub-Saharan African countries are transitioning to dolutegravir-based regimens, even for patients with extensive previous drug exposure, including first-generation integrase strand-transfer inhibitors (INSTI) such as raltegravir. Such exposure might have implications on cross-resistance to dolutegravir-based antiretroviral therapies (ART). CASE PRESENTATION: We report a 65 years old Cameroonian, previously exposed to raltegravir, and failing on third-line treatment with multi-drug resistance to darunavir/r and dolutegravir. Genotypic resistance testing (GRT) and viral tropism were performed during monitoring time points. The patient initiated ART in August 2007. At the time point of the first (29.04.2010), second (01.12.2017) and third (08.08.2019) GRT, prior ART exposure included 3TC, d4T, NVP and EFV; additionally TDF, DRV/r and RAL; and additionally ABC and DTG respectively. First GRT revealed mutations associated with resistance only to first-generation Non-nucleoside reverse transcriptase inhibitors (NNRTI). Second GRT revealed mutations associated with high-level resistance to all NRTIs, first generation NNRTIs, all ritonavir boosted protease inhibitors (PI/r), and all INSTI, while viral tropism (using geno2pheno) revealed a CCR5-tropic virus with a false positive rate (FPR) of 60.9% suggesting effectiveness of maraviroc (MRV). The third GRT showed high-level resistance to NRTI, NNRTI, all PI and all INSTI, with additional mutations (H221HY for NNRTI and S147G for INSTI), and a CCR5-tropic virus with a slightly reduced FPR (57.0%). Without any locally available active therapeutic option, the patient has been on a maintenance therapy with "DRV/r (600mg x 2/day)+TDF+3TC" and patient/family-centered adherence has been reinforced. Since the first viral load (VL) measurement in 2010, the patient has had 12 VL tests with the VL ranging from 4.97 Log to 6.44 Log copies/mL and the CD4 count never exceeded 200 cells/µL. CONCLUSIONS: As African countries transition to dolutegravir-based regimens, prior raltegravir-exposure may prompt selection (and potential transmission) of dolutegravir-resistance, supporting case surveillance.

HIV-1 integrase resistance associated mutations and the use of dolutegravir in Sub-Saharan Africa: a systematic review and meta-analysis protocol.

BACKGROUND: Sub-Saharan Africa carries the greatest burden of HIV-infection with increasing drug resistance burden, which requires improved patient management and monitoring. Current WHO recommendations suggest transitioning to dolutegravir-based (adults) or raltegravir-based-regimens (neonates) for initial antiretroviral therapy (ART) and as a suitable alternative in cases of multi-resistance in resource-limited settings. This review aims at synthesizing the current knowledge on dolutegravir use and integrase resistance-associated mutations found before the wide use of dolutegravir-based regimens. METHODS: This systematic review will include randomized and non-randomized trials, cohort, and cross-sectional studies published on dolutegravir use or integrase resistance-associated mutations in Sub-Saharan Africa. Searches will be conducted (from 2007 onwards) in PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Latin American and Caribbean Health Sciences Literature (LILAC), Web of Science, African Journals Online, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. Hand searching of the reference lists of relevant reviews and trials will be conducted and we will also look for conference abstracts. We will include studies of adults and/or children exposed to integrase inhibitors-based therapies; especially dolutegravir or raltegravir (which is our intervention of interest as compared to other antiretroviral regimens). We will exclude studies of patients with specific co-morbidities such as tuberculosis or opportunistic infections. Primary outcomes will be "the rate of viral suppression" and "the level of drug resistance" on integrase inhibitor-based regimens among patients in Sub-Saharan Africa. Secondary outcomes will be "the effect of baseline viremia on viral suppression," "the effect of treatment duration on viral suppression," "the proportion of patients with immune recovery," "the rate of non-adherence," "rate of adverse events;" "drug resistance according to different integrase inhibitor-based regimens," and "drug resistance according to viral subtypes/recombinants." Two reviewers will independently screen titles and abstracts, assess the full texts for eligibility, and extract data. If data permits, random effects models will be used where appropriate. Subgroup and additional analyses will be conducted to explore the potential sources of heterogeneity (e.g., age, sex, baseline viremia, CD4 following treatment, treatment duration, and adherence level). DISCUSSION: This review will help to strengthen evidence on the effectiveness of integrase strand transfer inhibitors by contributing to current knowledge on the use of dolutegravir and/or raltegravir (especially for neonates) in Sub-Saharan Africa. Results will therefore help in setting-up baseline data for an optimal management of people living with HIV as Sub-Saharan African countries are transitioning to dolutegravir-based regimens. Evidence will also support HIV/AIDS programs in identifying gaps and actions to be undertaken for improved long-term care and treatment of people living with HIV in Sub-Saharan Africa. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019122424.

TRIM5α 136Q, CCR5 Promoter 59029G And CCR264I Alleles Impact The Progression Of HIV In Children And Adolescents.

BACKGROUND: Children show various degrees of vulnerability regarding HIV infection and disease progression. This disparity presents challenges for the follow-up of infected children. Here we investigated reasons behind this variability focusing on some host-related HIV genes. METHODS: We screened 570 Cameroonian children and adolescents, aged 1 to 19 years old. Among them, 137 were followed over 4 years, from 2010 to 2015. Upon signing a proxy consent, children and adolescents were classified according to their age, CD4 count, viral load and clinical symptoms as long-term non-progressors (LTNP), slow progressors (SP) and rapid progressors (RP). Their blood was collected every 6 months and used for biological and host genetic polymorphism analyses. Five genes were genotyped: Trim5α (R136Q), CCR5 promoter 59029G, CCR2-64I, SDF 3'A and CCR5-Δ32. Exposed non-infected (HEU) and unexposed HIV negative children (HNEU) were recruited as control groups. RESULTS: Among the 5 genes studied, the protective allele of Trim5α (R136Q) was present in all LTNP and in 72.34% and 2.56% of SP and RP, respectively (p<0.0001). The CCR5 promoter 59029G/G was also more present in LTNP and SP than in RP (p=0.02; p=0.04). The protective CCR2-64I homozygous genotype was almost absent in all groups, only the heterozygous genotype was present with a significant difference between RP vs SP (p=0.0001), and SP vs LTNP (p=0.0002). The CCR2-∆32 was completely absent either as homozygous or heterozygous genotype. It was a monomorphic allele. SDF 3'A was almost present as homozygous wild-type genotype in our study population and was associated neither to disease acquisition nor to disease progression. CONCLUSION: Among the 5 genes described in the study, Trim 5α (R136Q), CCR5 promoter 59029G and CCR2V64I alleles were associated to the progression of HIV infection in children and adolescents.

CCR2 Genetic Polymorphism And Its Potential Effect On HIV Acquisition In A Population Of Children Living In The Northern Region Of Cameroon.

BACKGROUND AND OBJECTIVES: The association of chemokine receptor-2 (CCR2) polymorphism with HIV transmission or disease progression remains highly controversial. The role of CCR2-64I allele in HIV infection may differ from one population to another because of their genetic background. The objectives of this study were to characterize the CCR2 genetic polymorphism and to determine its potential effect in HIV acquisition in children living in the Northern Region of Cameroon. MATERIALS AND METHODS: A cross-sectional study was carried out in five health facilities in the Northern region of Cameroon. DNA was extracted from the Buffy coat of each participant using the QIAamp®DNA mini kit. The DNA extract was then subjected to polymorphic analyses. CCR2 genotypes were analyzed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The Chi-Squared test was used for the assessment of the Hardy-Weinberg equilibrium. RESULTS: A total of 134 children under 15 years comprised of 38 HIV-exposed infected (28.36%) and 96 HIV-exposed un-infected (71.64%) participants were recruited. Prevalences of 44.78% wild type homozygous, 48.52% heterozygous and 6.7% mutant homozygous alleles were found in the overall population. An allelic frequency of 29.69% for the mutant allele CCR2-64I was found in HIV-exposed un-infected individuals as compared to 34.21% in HIV-infected children (p=0.47). CONCLUSION: The CCR2-64I allele is relatively common in the Northern Region of Cameroon, with a similar distribution among HIV-exposed un-infected and infected children. As this allele alone does not seem to confer protection against HIV-1 infection, further studies using genotype-combination of CCR2 polymorphism and other single nucleotide polymorphisms would be of great relevance in both HIV prevention and novel therapeutic strategies.

CCR2 polymorphism and HIV: mutation in both mother and child is associated with higher transmission.

C-C motif chemokine receptor 2 (CCR2) is one of the co-receptors of HIV found on the surface of the target cell and studied as genetic factors known to be associated with HIV infection. This study investigates the influence of mothers' and children's CCR2 polymorphism on HIV acquisition in children. A cross-sectional study was performed in five hospitals in the Northern Region of Cameroon. Blood samples were collected from HIV-infected mothers and their exposed babies. DNA was extracted from the Buffy coat using the QIAamp®DNA mini kit (Qiagen). The DNA extract was subjected to Polymerase Chain Reaction (PCR) followed by Restriction Fragment Length Polymorphism. Hardy-Weinberg Equilibrium (HWE) was verified. A total of 113 HIV-positive mothers, and their 113 children (25 infected and 88 non-infected) under 15 years were enrolled. There was a significant relationship between mothers and children's polymorphisms (P = 0.000). There was a concordance of 57.5% between mothers and children genotypes (Kappa = 0.2, P = 0.001). Mothers carrying the CCR2-64I allele were 1.2 times more likely to have HIV-infected children compared to those without mutation (OR = 1.2, 95% CI: 0.5-3.0). Likewise children carrying the mutated phenotypes were 1.4 times more likely to be HIV-infected compared to those without mutation (OR = 1.4, 95% CI: 0.6-3.5). This risk increased to 2.0 (95% CI: 0.5-8.3) for children whose mothers also carried mutation, and decreased to 0.96 (95% CI: 0.2-3.8) for those whose mothers carried the wild type phenotype. In cases of a mutant phenotype in both mother and child, more attention should be paid during follow-up of children born from HIV-positive mother.

Differential expression of Fas receptors (CD95) and Fas ligands (CD95L) in HIV infected and exposed uninfected children in Cameroon versus unexposed children.

INTRODUCTION: The number of HIV exposed uninfected (HEU) infants is increasing as vertical transmission is reducing. This subpopulation requires more investigations. This study aimed at comparing the expression level of soluble Fas receptors (FasR) and ligands (FasL) between HIV infected, HEU and unexposed children. METHODS: Eighty eight HIV-1infected, 86 HEU and 38 HIV unexposed children were recruited. Soluble FasR and FasL were measured in their plasma. Mann-Whitney U-Test was used to compare groups with 95% confidence. Spearman coefficient was used to test the correlation with CD4 and viral load (VL). RESULTS: Overall plasma levels of FasR were higher than that of FasL. The concentration of FasR and FasL were significantly higher in HIV-1 infected children in comparison to HEU and unexposed children. There was no difference in the plasma level of FasL in HIV infected compared to HEU children. A significant difference was observed between HIV infected children and HEU children (P=0.001) for the FasL. FasR were higher in both HIV infected and unexposed children compared to HEU children. There was a positive correlation (rs=+0.4; p=0.01) in ARV treated children between CD4 count and FasL concentration. Significant negative correlation (rs=-0.3; p=0.040) in ARV naïve children was observed between CD4 percentage and FasL. Significant and positive correlation (rs=+0.4; p=0.008) was observed between the VL and FasL in HIV infected, treated or not. CONCLUSION: HEU children differ from HIV infected and unexposed children as the level of FasL/R expression is concerned. HEU should be considered different from HIV unexposed although exempt from virus as some immune dysfunctions have been reported among them.