Addressing an HIV cure in LMIC.

HIV-1 persists in infected individuals despite years of antiretroviral therapy (ART), due to the formation of a stable and long-lived latent viral reservoir. Early ART can reduce the latent reservoir and is associated with post-treatment control in people living with HIV (PLWH). However, even in post-treatment controllers, ART cessation after a period of time inevitably results in rebound of plasma viraemia, thus lifelong treatment for viral suppression is indicated. Due to the difficulties of sustained life-long treatment in the millions of PLWH worldwide, a cure is undeniably necessary. This requires an in-depth understanding of reservoir formation and dynamics. Differences exist in treatment guidelines and accessibility to treatment as well as social stigma between low- and-middle income countries (LMICs) and high-income countries. In addition, demographic differences exist in PLWH from different geographical regions such as infecting viral subtype and host genetics, which can contribute to differences in the viral reservoir between different populations. Here, we review topics relevant to HIV-1 cure research in LMICs, with a focus on sub-Saharan Africa, the region of the world bearing the greatest burden of HIV-1. We present a summary of ART in LMICs, highlighting challenges that may be experienced in implementing a HIV-1 cure therapeutic. Furthermore, we discuss current research on the HIV-1 latent reservoir in different populations, highlighting research in LMIC and gaps in the research that may facilitate a global cure. Finally, we discuss current experimental cure strategies in the context of their potential application in LMICs.

The within-host fitness of HIV-1 increases with age in ART-naïve HIV-1 subtype C infected children.

As the immune system develops with age, children combat infections better. HIV-1, however, targets an activated immune system, potentially rendering children increasingly permissive to HIV-1 infection as they grow. How HIV-1 fitness changes with age in children is unknown. Here, we estimated the within-host basic reproductive ratio, R0, a marker of viral fitness, in HIV-1 subtype C-infected children in India, aged between 84 days and 17 years. We measured serial viral load and CD4 T cell counts in 171 children who initiated first-line ART. For 25 children, regular and frequent measurements provided adequate data points for analysis using a mathematical model of viral dynamics to estimate R0. For the rest, we used CD4 counts for approximate estimation of R0. The viral load decline during therapy was biphasic. The mean lifespans of productively and long-lived infected cells were 1.4 and 27.8 days, respectively. The mean R0 was 1.5 in children aged < 5 years, increased with age, and approached 6.0 at 18 years, close to 5.8 estimated previously for adults. The tolerogenic immune environment thus compromises HIV-1 fitness in young children. Early treatment initiation, when the R0 is small, will likely improve viral control, in addition to suppressing the latent reservoir.

Implementing Rapid Initiation of Antiretroviral Therapy for Acute HIV Infection Within a Routine Testing and Linkage to Care Program in Chicago.

Growing evidence suggests that rapid initiation of antiretroviral therapy for HIV improves care continuum outcomes. We evaluated process and clinical outcomes for rapid initiation in acute HIV infection within a multisite health care-based HIV testing and linkage to care program in Chicago. Through retrospective analysis of HIV testing data (2016-2017), we assessed linkage to care, initiation of antiretroviral therapy, and viral suppression. Of 334 new HIV diagnoses, 33 (9.9%) individuals had acute HIV infection. Median time to linkage was 11 (interquartile range [IQR]: 5-19.5) days, with 15 days (IQR 5-27) to initiation of antiretroviral therapy. Clients achieved viral suppression at a median of 131 (IQR: 54-188) days. Of all, 69.7% were retained in care, all of whom were virally suppressed. Sites required few additional resources to incorporate rapid initiation into existing processes. Integration of rapid initiation of antiretroviral therapy into existing HIV screening programs is a promising strategy for scaling up this important intervention.

Optimizing Antiretroviral Therapy in Treatment-Experienced Patients Living with HIV: A Critical Review of Switch and Simplification Strategies. An Opinion of the HIV Practice and Research Network of the American College of Clinical Pharmacy.

Simplifying or switching antiretroviral therapy (ART) in treatment-experienced people living with HIV (PLWH) may improve adherence, tolerability, toxicities, and/or drug-drug interactions. The purpose of this review is to critically evaluate the literature for efficacy and safety associated with switching or simplifying ART in treatment-experienced PLWH. A systematic literature search using MEDLINE was performed from January 1, 2010 to April 30, 2018. References within articles of interest, the Department of Health and Human Services guidelines, and conference abstracts were also reviewed. Switch/simplification strategies were categorized as those supported by high-level clinical evidence and those with emerging data. Rates of virologic suppression were noninferior for several switch/simplification strategies when compared to baseline ART. Potential for reducing adverse events was also seen. Additional evidence for some strategies, including most 2-drug regimens, is needed before they can be recommended.

Impact of three decades of antiretroviral therapy in a longitudinal population cohort study.

BACKGROUND: We have used a comprehensive HIV population to characterize antiretroviral therapy (ART), drug class selection, pill burden, drug costs and health outcomes over the entire span of the HIV epidemic. METHODS: Antiretroviral (ARV) use (drugs, classes, formulations) and both the laboratory and clinical outcomes (HIV-1 RNA, CD4+ T-cell count and mortality) were determined for all patients in Southern Alberta, Canada, at each year-end between 1986 and 2017. Pill burden, cumulative drug exposure and costs were calculated for each year. RESULTS: The number of ARV-treated patients increased from 29.6% (77/260) in 1989 to 93.4% (1,814/1,943) in 2017. Regimen selection showed continuous adjustments for toxicity, resistance, pill burden and adherence. Dramatic improvements in outcomes were seen. In 1997, 22.4% of treated patients had an undetectable viral load, this has been consistently around 90% since 2010 (92.7% in 2017). While HIV-related annual mortality rate declined from 11.0% in 1994 to 0.1% in 2017, all-cause mortality remained relatively stable from 1997 onwards. ART pill burden escalated in 1997 (12.4/day), then decreased to 2.1/day in 2016. Mean ART cost increased in 1997 (CAN$905/month/regimen in 1997, $1,223 in 2016). Mean cumulative lifetime exposure to protease inhibitors is 5.98 ±4.9 and to nucleoside reverse transcriptase inhibitors 8.8 ±6.2 years. CONCLUSIONS: Our findings demonstrate not only the immense burden that HIV has imposed on both patients and society, but also the substantial benefit of ART on patient outcomes. They show that research, patient engagement and programme support can with time minimize the harmful long-term effects of HIV-infection.

Strategies to improve adherence to antiretroviral therapy and retention in care for people living with HIV in high-income countries: a protocol for an overview of systematic reviews.

INTRODUCTION: While access to antiretroviral therapy (ART) for people living with HIV has expanded in recent years, additional efforts are required to support adherence to medication and retention in care. Interventions should be applicable in real-world settings and amenable to widespread use. The objectives of this overview are to identify effective pragmatic interventions that increase adherence to ART and retention in care for people living with HIV at high risk for suboptimal adherence and retention in high-income countries. METHODS AND ANALYSIS: We will conduct an overview of systematic reviews of studies on interventions which target improved adherence to medication and retention in care among high-risk people living with HIV in high-income countries (men who have sex with men, African, Caribbean and black people, sex workers, people who inject drugs, indigenous people and other socially marginalised groups). We will search the following databases: PubMed, EMBASE (Exerpta Medica Database), CINAHL (Cumulative Index to Nursing and Allied Health Literature), PsycINFO, Web of Science and the Cochrane Library. We will conduct screening, data extraction and assessment of methodological quality of the systematic reviews. Analysis will be narrative. Our findings will be interpreted in light of the certainty of the evidence, level of pragmatism, setting and population of interest. ETHICS AND DISSEMINATION: Only published secondary data will be used in this study, and therefore ethics approval is not required. Our findings will be disseminated as peer-reviewed manuscripts, conference abstracts and through community activities. The findings from this overview will inform a mixed-methods study among people living with HIV and health workers in Ontario, Canada.

A Longitudinal Analysis of Daily Pill Burden and Likelihood of Optimal Adherence to Antiretroviral Therapy Among People Living With HIV Who Use Drugs.

OBJECTIVES: Among people living with HIV (PLWH), high levels of adherence to prescribed antiretroviral therapy (ART) is required to achieve optimal treatment outcomes. However, little is known about the effects of daily pill burden on adherence amongst PLWH who use drugs. We sought to investigate the association between daily pill burden and adherence to ART among members of this key population in Vancouver, Canada. METHODS: We used data from the AIDS Care Cohort to Evaluate Exposure to Survival Services study, a long-running community-recruited cohort of PLWH who use illicit drugs linked to comprehensive HIV clinical records. The longitudinal relationship between daily pill burden and the odds of ≥95% adherence to ART among ART-exposed individuals was analyzed using multivariable generalized linear mixed-effects modeling, adjusting for sociodemographic, behavioural, and structural factors linked to adherence. RESULTS: Between December 2005 and May 2014, the study enrolled 770 ART-exposed participants, including 257 (34%) women, with a median age of 43 years. At baseline, 437 (56.7%) participants achieved ≥95% adherence in the previous 180 days. Among all interview periods, the median adherence was 100% (interquartile range 71%-100%). In a multivariable model, a greater number of pills per day was negatively associated with ≥95% adherence (adjusted odds ratio [AOR] 0.87 per pill, 95% confidence interval [CI] 0.84-0.91). Further analysis showed that once-a-day ART regimens were positively associated with optimal adherence (AOR 1.39, 95% CI 1.07-1.80). CONCLUSIONS: In conclusion, simpler dosing demands (ie, fewer pills and once-a-day single tablet regimens) promoted optimal adherence among PLWH who use drugs. Our findings highlight the need for simpler dosing to be encouraged explicitly for PWUD with multiple adherence barriers.

Routine CD4 monitoring in HIV patients with viral suppression: Is it really necessary? A Portuguese cohort.

PURPOSE: CD4 cell-count has been regarded as the key surrogate marker for prognostic staging and therapeutic monitoring of HIV-infected individuals. Our purpose was to assess the probability of maintaining a CD4 count >200 cells/µL in patients with continuous viral suppression and CD4 cell counts >200 cells/µL. METHODS: Retrospective cohort study of HIV-infected patients, treatment naïve, who started antiretroviral therapy between 2007 and 2011. We estimated the probability of maintaining CD4 counts >200 cells/µL during continuous viral suppression using the Kaplan-Meier method. The hazard ratios of a CD4 count <200 cells/µL were estimated and compared using Cox proportional hazards regression. RESULTS: 401 patients were included: 70.1% men; median age 37 years; 98.8% HIV-1 infected. The median duration of continuous viral suppression with CD4 counts >200 cells/µL was 40.5 months. Ninety-three percent of patients maintained CD4 counts ≥200 cells/µL during the period of continuous viral suppression. Compared with those with an initial CD4 count ≥350 cells/µL, patients with initial CD4 count <300 cells/µL had a significantly higher risk of a CD4 count <200 cells/µL. Patients with viral suppression and CD4 counts ≥350 cells/µL had a 97.1% probability of maintaining CD4 cell counts ≥200 cells/µL for 48 months. CONCLUSIONS: The probability of a CD4 count <200 cells/µL in an HIV-infected patient with viral suppression and CD4 ≥350 cells/µL was very low. These data suggests less frequent monitoring of CD4 counts in these patients.

Switch to maraviroc with darunavir/r, both QD, in patients with suppressed HIV-1 was well tolerated but virologically inferior to standard antiretroviral therapy: 48-week results of a randomized trial.

OBJECTIVES: Primary study outcome was absence of treatment failure (virological failure, VF, or treatment interruption) per protocol at week 48. METHODS: Patients on 3-drug ART with stable HIV-1 RNA <50 copies/mL and CCR5-tropic virus were randomized 1:1 to maraviroc with darunavir/ritonavir qd (study arm) or continue current ART (continuation arm). RESULTS: In June 2015, 115 patients were evaluable for the primary outcome (56 study, 59 continuation arm). The study was discontinued due to excess of VF in the study arm (7 cases, 12.5%, vs 0 in the continuation arm, p = 0.005). The proportion free of treatment failure was 73.2% in the study and 59.3% in the continuation arm. Two participants in the study and 10 in the continuation arm discontinued therapy due to adverse events (p = 0.030). At VF, no emergent drug resistance was detected. Co-receptor tropism switched to non-R5 in one patient. Patients with VF reported lower adherence and had lower plasma drug levels. Femoral bone mineral density was significantly improved in the study arm. CONCLUSION: Switching to maraviroc with darunavir/ritonavir qd in virologically suppressed patients was associated with improved tolerability but was virologically inferior to 3-drug therapy.

Highlights in HIV, 2016.

Research in HIV-infection continues to grow every year. Reports published in journals or presented at conferences in 2016-2017 have brought light to some issues that had been highly debated. We have selected three conceptual publications, which we find include important information for clinicians taking care of HIV-infected patients.

Acute Care Management of the HIV-Infected Patient: A Report from the HIV Practice and Research Network of the American College of Clinical Pharmacy.

OBJECTIVE: Patients infected with human immunodeficiency virus (HIV) admitted to the hospital have complex antiretroviral therapy (ART) regimens with an increased medication error rate upon admission. This report provides a resource for clinicians managing HIV-infected patients and ART in the inpatient setting. METHODS: A survey of the authors was conducted to evaluate common issues that arise during an acute hospitalization for HIV-infected patients. After a group consensus, a review of the medical literature was performed to determine the supporting evidence for the following HIV-associated hospital queries: admission/discharge orders, antiretroviral hospital formularies, laboratory monitoring, altered hepatic/renal function, drug-drug interactions (DDIs), enteral administration, and therapeutic drug monitoring. RESULTS: With any hospital admission for an HIV-infected patient, a specific set of procedures should be followed including a thorough admission medication history and communication with the ambulatory HIV provider to avoid omissions or substitutions in the ART regimen. DDIs are common and should be reviewed at all transitions of care during the hospital admission. ART may be continued if enteral nutrition with a feeding tube is deemed necessary, but the entire regimen should be discontinued if no oral access is available for a prolonged period. Therapeutic drug monitoring is not generally recommended but, if available, should be considered in unique clinical scenarios where antiretroviral pharmacokinetics are difficult to predict. ART may need adjustment if hepatic or renal insufficiency ensues. CONCLUSIONS: Treatment of hospitalized patients with HIV is highly complex. HIV-infected patients are at high risk for medication errors during various transitions of care. Baseline knowledge of the principles of antiretroviral pharmacotherapy is necessary for clinicians managing acutely ill HIV-infected patients to avoid medication errors, identify DDIs, and correctly dose medications if organ dysfunction arises. Timely ambulatory follow-up is essential to prevent readmissions and facilitate improved transitions of care.

Initial Management of Patients with HIV Infection.

Human immunodeficiency virus (HIV) infection has become a treatable chronic disease with near-normal life expectancy when patients receive antiretroviral therapy (ART). Family physicians and other primary care clinicians commonly provide long-term comprehensive care for persons with HIV infection. This article describes the scope of initial care, including obtaining a thorough history; physical examination for HIV-associated manifestations; attention to HIV-specific immunization schedules; routine and HIV-specific laboratory evaluation; and ensuring standard health care maintenance to prevent HIV- and non-HIV-related morbidity and mortality. Clinicians should encourage combination ART as early as possible, although careful assessment of patient readiness and ability to sustain lifelong treatment must be weighed. After ART initiation, monitoring viral load and CD4 lymphocyte response is essential to ensure viral suppression and evaluate immune system restoration. Opportunistic infections are now less common than in the past because ART usually prevents or markedly delays progression to advanced HIV disease. The most important reasons for consultation or comanagement with an HIV expert include management of antiretroviral drug resistance or drug toxicities, as well as special circumstances such as viral hepatitis coinfection or pregnancy.

Towards Developing an Initial Programme Theory: Programme Designers and Managers Assumptions on the Antiretroviral Treatment Adherence Club Programme in Primary Health Care Facilities in the Metropolitan Area of Western Cape Province, South Africa.

BACKGROUND: The antiretroviral adherence club intervention was rolled out in primary health care facilities in the Western Cape province of South Africa to relieve clinic congestion, and improve retention in care, and treatment adherence in the face of growing patient loads. We adopted the realist evaluation approach to evaluate what aspects of antiretroviral club intervention works, for what sections of the patient population, and under which community and health systems contexts, to inform guidelines for scaling up of the intervention. In this article, we report on a step towards the development of a programme theory-the assumptions of programme designers and health service managers with regard to how and why the adherence club intervention is expected to achieve its goals and perceptions on how it has done so (or not). METHODS: We adopted an exploratory qualitative research design. We conducted a document review of 12 documents on the design and implementation of the adherence club intervention, and key informant interviews with 12 purposively selected programme designers and managers. Thematic content analysis was used to identify themes attributed to the programme actors, context, mechanisms, and outcomes. Using the context-mechanism-outcome configurational tool, we provided an explanatory focus of how the adherence club intervention is roll-out and works guided by the realist perspective. RESULTS: We classified the assumptions of the adherence club designers and managers into the rollout, implementation, and utilisation of the adherence club programme, constructed around the providers, management/operational staff, and patients, respectively. Two rival theories were identified at the patient-perspective level. We used these perspectives to develop an initial programme theory of the adherence club intervention, which will be tested in a later phase. CONCLUSION: The perspectives of the programme designers and managers provided an important step towards developing an initial programme theory, which will guide our realist evaluation of the adherence club programme in South Africa.

Influence of pharmacotherapy complexity on compliance with the therapeutic objectives for HIV+ patients on antiretroviral treatment concomitant with therapy for dyslipidemia. INCOFAR Project.

OBJECTIVES: To analyze the relationship between pharmacotherapeutical complexity and compliance of therapeutic objectives in HIV+ patients on antiretroviral treatment and concomitant dyslipidemia therapy. MATERIALS AND METHODS: A retrospective observational study including HIV patients on stable antiretroviral treatment during the past 6 months, and dyslipidemia treatment between January and December, 2013. The complexity index was calculated with the tool developed by McDonald et al. Other variables analyzed were: age, gender, risk factor of HIV, smoking, alcoholism and drugs, psychiatric disorders, adherence to antiretroviral treatment and lipid lowering drugs, and clinical parameters (HIV viral load, CD4 count, plasma levels of total cholesterol, LDL, HDL, and triglycerides). In order to determine the predictive factors associated with the compliance of therapeutic objectives, univariate analysis was conducted through logistical regression, followed by a multivariate analysis. RESULTS: The study included 89 patients; 56.8% of them met the therapeutic objectives for dyslipidemia. The complexity index was significantly higher (p = 0.02) in those patients who did not reach the objective values (median 51.8 vs. 38.9). Adherence to lipid lowering treatment was significantly associated with compliance of the therapeutic objectives established for dyslipidemia treatment. A 67.0% of patients met the objectives for their antiretroviral treatment; however, the complexity index was not significantly higher (p = 0.06) in those patients who did not meet said objectives. CONCLUSIONS: Pharmacotherapeutical complexity represents a key factor in terms of achieving health objectives in HIV+ patients on treatment for dyslipidemia.

Objetivos: Analizar la relación entre complejidad farmacoterapéutica y cumplimiento de los objetivos terapéuticos en pacientes VIH+ con tratamiento antirretroviral activo y concomitante para la dislipemia. Material y métodos: Estudio observacional retrospectivo. Se seleccionaron pacientes con VIH en tratamiento antirretroviral estable durante los últimos 6 meses y tratamiento para la dislipemia entre enero-diciembre de 2013. Se calculó el índice de complejidad a través de la herramienta desarrollada por Mc Donald et al. Otras variables analizadas fueron: edad; sexo; factor de riesgo de adquisición del VIH; consumo de tabaco, alcohol y drogas; alteraciones psiquiátricas; adherencia al TAR y a fármacos hipolipemiantes y parámetros clínicos (carga viral VIH, recuento de CD4, niveles plasmáticos de colesterol total, LDL, HDL, y triglicéridos). Para determinar factores predictivos asociados con el cumplimiento de los objetivos terapéuticos se realizó un análisis univariante mediante regresión logística y, posteriormente, un análisis multivariante. Resultados: Se incluyeron 89 pacientes. El 56,8% cumplieron los objetivos terapéuticos para la dislipemia. El índice de complejidad fue significativamente mayor (p = 0,02) en pacientes que no alcanzaron los valores objetivo (mediana de 51,8 vs 38,9). La adherencia al tratamiento hipolipemiante fue relacionada de forma significativa con el cumplimiento de los objetivos terapéuticos establecidos para el tratamiento de la dislipemia. El 67,0% cumplieron los objetivos para el TAR, sin embargo el índice de complejidad no fue significativamente mayor (p = 0,06) en los pacientes que no cumplían objetivos. Conclusiones: La complejidad farmacoterapéutica constituye un factor clave en la consecución de los objetivos de salud en pacientes VIH+ que reciben tratamiento para la dislipemia.

CD4 Cell Count: Declining Value for Antiretroviral Therapy Eligibility.

Antiretroviral therapy (ART) policy for people living with human immunodeficiency virus (HIV) has historically been based on clinical indications, such as opportunistic infections and CD4 cell counts. Studies suggest that CD4 counts early in HIV infection do not predict relevant public health outcomes such as disease progression, mortality, and HIV transmission in people living with HIV. CD4 counts also vary widely within individuals and among populations, leading to imprecise measurements and arbitrary ART initiation. To capture the clinical and preventive benefits of treatment, the global HIV response now focuses on increasing HIV diagnosis and ART coverage. CD4 counts for ART initiation were necessary when medications were expensive and had severe side effects, and when the impact of early ART initiation was unclear. However, current evidence suggests that although CD4 counts may still play a role in guiding clinical care to start prophylaxis for opportunistic infections, CD4 counts should cease to be required for ART initiation.

Patient-Reported Symptoms over 48 Weeks in a Randomized, Open-Label, Phase 3b Non-inferiority Trial of Adults with HIV Switching to Coformulated Elvitegravir, Cobicistat, Emtricitabine, and Tenofovir DF Versus Continuation of Ritonavir-Boosted Protease Inhibitor with Emtricitabine and Tenofovir DF.

BACKGROUND: Coformulated elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (EVG/COBI/FTC/TDF; Stribild(®)) is a recommended integrase inhibitor-based regimen in treatment guidelines from the US Department of Health and Human Services and the British HIV Association. The purpose of this analysis was to determine the change in patient-reported symptoms over time among HIV-infected adults who switch to Stribild(®) versus those continuing on a protease inhibitor (PI) with FTC/TDF. METHODS: A secondary analysis was conducted on the STRATEGY-PI study (GS-US-236-0115, ClinicalTrials.gov NCT01475838), a randomized, open-label, phase 3b trial of HIV-infected adults taking a PI with FTC/TDF who were randomly assigned (2:1) either to Stribild(®) (switch) or continuation of their existing regimen (no-switch). Logistic regressions and longitudinal modeling were conducted to evaluate the relationship of treatment with bothersome symptoms. RESULTS: At week 4 as compared with baseline, the switch group experienced a statistically significantly lower prevalence in five symptoms (diarrhea/loose bowels, bloating/pain/gas in stomach, pain/numbness/tingling in hands/feet, nervous/anxious, and trouble remembering). The lower prevalence of diarrhea/loose bowels, bloating/pain/gas in stomach, and pain/numbness/tingling in hands/feet observed at week 4 was maintained over time. While there were no significant differences between groups in the prevalence of sad/down/depressed and problems with sex at week 4 or week 48, longitudinal models indicated the switch group had a statistically significantly decreased prevalence in both symptoms from week 4 to week 48. As compared with the no-switch group, higher levels of satisfaction with treatment were experienced by patients in the switch group at the first follow-up visit and at week 24. CONCLUSIONS: In this study sample, a switch from a ritonavir-boosted PI, FTC, and TDF regimen to coformulated EVG/COBI/FTC/TDF was associated with more treatment satisfaction and a reduction in the prevalence of patient-reported diarrhea/loose bowel symptoms, which was maintained over the 48-week study period.

Pretreatment HIV drug resistance increases regimen switches in sub-Saharan Africa.

BACKGROUND: After the scale-up of antiretroviral therapy (ART) for human immunodeficiency virus (HIV) infection in Africa, increasing numbers of patients have pretreatment drug resistance. METHODS: In a large multicountry cohort of patients starting standard first-line ART in six African countries, pol genotyping was retrospectively performed if viral load (VL) ≥1000 cps/mL. Pretreatment drug resistance was defined as a decreased susceptibility to ≥1 prescribed drug. We assessed the effect of pretreatment drug resistance on all-cause mortality, new AIDS events and switch to second-line ART due to presumed treatment failure, using Cox models. RESULTS: Among 2579 participants for whom a pretreatment genotype was available, 5.5% had pretreatment drug resistance. Pretreatment drug resistance was associated with an increased risk of regimen switch (adjusted hazard ratio [aHR] 3.80; 95% confidence interval [CI], 1.49-9.68; P = .005) but was not associated with mortality (aHR 0.75, 95% CI, .24-2.35; P = .617) or new AIDS events (aHR 1.06, 95% CI, .68-1.64; P = .807). During three years of follow up, 106 (4.1%) participants switched to second-line, of whom 18 (17.0%) switched with VL < 1000 cps/mL, 7 (6.6%) with VL ≥ 1000 cps/mL and no drug resistance mutations (DRMs), 46 (43.4%) with VL ≥ 1000 cps/mL and ≥1 DRMs; no HIV RNA data was available for 32 (30.2%) participants. CONCLUSIONS: Given rising pretreatment HIV drug resistance levels in sub-Saharan Africa, these findings underscore the need for expanded access to second-line ART. VL monitoring can improve the accuracy of failure detection and efficiency of switching practices.

Algorithm evolution for drug resistance prediction: comparison of systems for HIV-1 genotyping.

BACKGROUND: Different genotypic HIV resistance algorithms are based on different rules. They may therefore result in different drug-resistance interpretations for the same patient sample. In particular, for early periods of new retroviral inhibitors or classes, sequence interpretation is expected to vary. One would, however, assume that those differences between systems wane with growing experience and that different algorithms yield similar results for well-established drugs. METHODS: To assess the concordance of the Agence Nationale de Recherche sur le SIDA (ANRS), Rega and Stanford-HIVdb algorithms and their evolution over time, we analysed 284 routine samples with the current versions of each algorithm in 2004 and 2013. For 446 recent clinical sequences the differences for actual drugs were analysed. Scoring as 'susceptible' by one algorithm and 'resistant' by a second one defined a discordance. RESULTS: The longitudinal analysis showed similar overall discordances for both time points as well as an evolution over time. The actual analysis demonstrated a higher overall discordance rate, mainly for certain drugs. Most deviations reflected differences between the ANRS and the other two algorithms. CONCLUSIONS: This study demonstrates discordances between three most commonly used interpretation tools even for long-available drugs. It thereby reveals a need for further adjustment and improvement of current interpretation tools and may point at a possibly crucial role of subtype-specific information.