UK Collaborative HIV Cohort Research Articles

HIV-1 drug resistance in people on dolutegravir-based antiretroviral therapy: a collaborative cohort analysis

The widespread use of the integrase strand transfer inhibitor (INSTI) dolutegravir in first-line and second-line antiretroviral therapy (ART) might facilitate emerging resistance. The DTG RESIST study combined data from HIV cohorts to examine patterns of drug resistance mutations (DRMs) and identify risk factors for dolutegravir resistance. We included cohorts with INSTI resistance data from two collaborations (ART Cohort Collaboration, International epidemiology Databases to Evaluate AIDS in Southern Africa), and the UK Collaborative HIV Cohort. Eight cohorts from Canada, France, Germany, Italy, the Netherlands, Switzerland, South Africa, and the UK contributed data on individuals who were viraemic on dolutegravir-based ART and underwent genotypic resistance testing. Individuals with unknown dolutegravir initiation date were excluded. Resistance levels were categorised using the Stanford algorithm. We identified risk factors for resistance using mixed-effects ordinal logistic regression models. We included 599 people with genotypic resistance testing on dolutegravir-based ART between May 22, 2013, and Dec 20, 2021. Most had HIV-1 subtype B (n=351, 59%), a third had been exposed to first-generation INSTIs (n=193, 32%), 70 (12%) were on dolutegravir dual therapy, and 18 (3%) were on dolutegravir monotherapy. INSTI DRMs were detected in 86 (14%) individuals; 20 (3%) had more than one mutation. Most (n=563, 94%) were susceptible to dolutegravir, seven (1%) had potential low, six (1%) low, 17 (3%) intermediate, and six (1%) high-level dolutegravir resistance. The risk of dolutegravir resistance was higher on dolutegravir monotherapy (adjusted odds ratio [aOR] 34·1, 95% CI 9·93-117) and dolutegravir plus lamivudine dual therapy (aOR 9·21, 2·20-38·6) compared with combination ART, and in the presence of potential low or low (aOR 5·23, 1·32-20·7) or intermediate or high-level (aOR 13·4, 4·55-39·7) nucleoside reverse transcriptase inhibitor (NRTI) resistance. Among people with viraemia on dolutegravir-based ART, INSTI DRMs and dolutegravir resistance were rare. NRTI resistance substantially increased the risk of dolutegravir resistance, which is of concern, notably in resource-limited settings. Monitoring is important to prevent resistance at the individual and population level and ensure the long-term sustainability of ART. US National Institutes of Health, Swiss National Science Foundation.

Life expectancy after 2015 of adults with HIV on long-term antiretroviral therapy in Europe and North America: a collaborative analysis of cohort studies

The life expectancy of people with HIV taking antiretroviral therapy (ART) has increased substantially over the past 25 years. Most previous studies of life expectancy were based on data from the first few years after starting ART, when mortality is highest. However, many people with HIV have been successfully treated with ART for many years, and up-to-date prognosis data are needed. We aimed to estimate life expectancy in adults with HIV on ART for at least 1 year in Europe and North America from 2015 onwards. We used data for people with HIV taking ART from the Antiretroviral Therapy Cohort Collaboration and the UK Collaborative HIV Cohort Study. Included participants started ART between 1996 and 2014 and had been on ART for at least 1 year by 2015, or started ART between 2015 and 2019 and survived for at least 1 year; all participants were aged at least 16 years at ART initiation. We used Poisson models to estimate the associations between mortality and demographic and clinical characteristics, including CD4 cell count at the start of follow-up. We also estimated the remaining years of life left for people with HIV aged 40 years who were taking ART, and stratified these estimates by variables associated with mortality. These estimates were compared with estimates for years of life remaining in a corresponding multi-country general population. Among 206 891 people with HIV included, 5780 deaths were recorded since 2015. We estimated that women with HIV at age 40 years had 35·8 years (95% CI 35·2-36·4) of life left if they started ART before 2015, and 39·0 years (38·5-39·5) left if they started ART after 2015. For men with HIV, the corresponding estimates were 34·5 years (33·8-35·2) and 37·0 (36·5-37·6). Women with CD4 counts of fewer than 49 cells per μL at the start of follow-up had an estimated 19·4 years (18·2-20·5) of life left at age 40 years if they started ART before 2015 and 24·9 years (23·9-25·9) left if they started ART after 2015. The corresponding estimates for men were 18·2 years (17·1-19·4) and 23·7 years (22·7-24·8). Women with CD4 counts of at least 500 cells per μL at the start of follow-up had an estimated 40·2 years (39·7-40·6) of life left at age 40 years if they started ART before 2015 and 42·0 years (41·7-42·3) left if they started ART after 2015. The corresponding estimates for men were 38·0 years (37·5-38·5) and 39·2 years (38·7-39·7). For people with HIV on ART and with high CD4 cell counts who survived to 2015 or started ART after 2015, life expectancy was only a few years lower than that in the general population, irrespective of when ART was started. However, for people with low CD4 counts at the start of follow-up, life-expectancy estimates were substantially lower, emphasising the continuing importance of early diagnosis and sustained treatment of HIV. US National Institute on Alcohol Abuse and Alcoholism and UK Medical Research Council.

Associations of modern initial antiretroviral drug regimens with all-cause mortality in adults with HIV in Europe and North America: a cohort study

Over the past decade, antiretroviral therapy (ART) regimens that include integrase strand inhibitors (INSTIs) have become the most commonly used for people with HIV starting ART. Although trials and observational studies have compared virological failure on INSTI-based with other regimens, few data are available on mortality in people with HIV treated with INSTIs in routine care. Therefore, we compared all-cause mortality between different INSTI-based and non-INSTI-based regimens in adults with HIV starting ART from 2013 to 2018. This cohort study used data on people with HIV in Europe and North America from the Antiretroviral Therapy Cohort Collaboration (ART-CC) and UK Collaborative HIV Cohort (UK CHIC). We studied the most common third antiretroviral drugs (additional to nucleoside reverse transcriptase inhibitor) used from 2013 to 2018: rilpivirine, darunavir, raltegravir, elvitegravir, dolutegravir, efavirenz, and others. Adjusted hazard ratios (aHRs; adjusted for clinical and demographic characteristics, comorbid conditions, and other drugs in the regimen) for mortality were estimated using Cox models stratified by ART start year and cohort, with multiple imputation of missing data. 62 500 ART-naive people with HIV starting ART (12 422 [19·9%] women; median age 38 [IQR 30-48]) were included in the study. 1243 (2·0%) died during 188 952 person-years of follow-up (median 3·0 years [IQR 1·6-4·4]). There was little evidence that mortality rates differed between regimens with dolutegravir, elvitegravir, rilpivirine, darunavir, or efavirenz as the third drug. However, mortality was higher for raltegravir compared with dolutegravir (aHR 1·49, 95% CI 1·15-1·94), elvitegravir (1·86, 1·43-2·42), rilpivirine (1·99, 1·49-2·66), darunavir (1·62, 1·33-1·98), and efavirenz (2·12, 1·60-2·81) regimens. Results were similar for analyses making different assumptions about missing data and consistent across the time periods 2013-15 and 2016-18. Rates of virological suppression were higher for dolutegravir than other third drugs. This large study of patients starting ART since the introduction of INSTIs found little evidence that mortality rates differed between most first-line ART regimens; however, raltegravir-based regimens were associated with higher mortality. Although unmeasured confounding cannot be excluded as an explanation for our findings, virological benefits of first-line INSTIs-based ART might not translate to differences in mortality. US National Institute on Alcohol Abuse and Alcoholism and UK Medical Research Council.

Life expectancy of people with HIV on long-term antiretroviral therapy in Europe and North America: a cohort study

BackgroundThe life expectancy of people with HIV starting combination antiretroviral therapy (ART) has increased substantially over the past 25 years. However, individuals treated before 1996 or with less effective and more toxic regimens than those currently available might have a worse prognosis. We estimated life expectancy from 2015 onwards, comparing people with HIV who started ART in different time periods since 1996. MethodsData were derived from 20 European and North American cohorts (Antiretroviral Therapy Cohort Collaboration and UK Collaborative HIV Cohort Study), for people with HIV who started potent ART after 1996 and were still on ART in 2015, or who started ART after 2015 and survived for at least 1 year. Follow-up started on or after Jan 1, 2015. Associations between mortality and demographic characteristics and biomarkers (CD4 and CD8 count in cells per μL and HIV-1 RNA viral load) at follow-up start were estimated using multivariable Poisson models. Estimated mortality rates in 5-year age bands were entered into life tables that contain follow-up information to estimate expected remaining life expectancy, stratified by sex and variables associated with mortality, and standardised to the proportion of people with HIV in each stratum. Life expectancy was compared with the French general population, as more data were available for France than for other countries included in the analyses. FindingsOf the 206 891 people with HIV eligible for inclusion from the cohort data, 5780 died during 619 356 person-years of follow-up after 2015. For women, the standardised remaining years of life expectancy at age 40 years for individuals starting ART between 1996 and 2014 was 36·0 years (95% CI 35·4–36·6), whereas it was 39·4 years (39·0–39·8) for individuals starting after 2015 (general population comparator 46·0 years). Corresponding figures for men were 34·7 years (34·1–35·3) and 37·2 years (36·6–38·8), respectively (general population comparator 40·3 years). For women starting ART between 1996 and 2014, with a CD4 count of 0–49 cells per μL at the commencement of follow-up, remaining life expectancy at age 40 years was 19·4 years (95% CI 18·2–20·6), rising to 40·4 years (40·0–40·8) for people with a CD4 count of 500 cells per μL or greater at commencement of follow-up. Corresponding figures for women starting ART after 2015 were 24·9 years (23·9–25·9) and 42·6 years (422–43·0), respectively. For men starting ART between 1996 and 2014 with a CD4 count of 0–49 cells per μL at commencement of follow-up, remaining life expectancy at age 40 years was 18·2 years (17·0–19·4), rising to 38·2 years (37·6–38·8) for men with a CD4 count of 500 cells per μL or more at commencement of follow-up. Corresponding remaining life expectancy for men starting ART after 2015 was 23·7 years (22·7–24·7) and 39·5 years (38·9–40·1), respectively. InterpretationFor people with HIV on long-term ART with high CD4 cell counts, life expectancies are estimated to be close to those of the general population, regardless of when they started ART. However, for people with HIV with low CD4 cell counts, estimates of remaining life expectancy are up to 30 years lower than in the general population, indicating the importance of early diagnosis and sustained treatment. FundingUS National Institute on Alcohol Abuse and Alcoholism, UK Medical Research Council.

Association of pregnancy with engagement in HIV care among women with HIV in the UK: a cohort study.

Women with HIV face challenges in engaging in HIV care post partum. We aimed to examine changes in engagement in HIV care through clinic attendance before, during, and after pregnancy, compared with matched women with HIV who had never had a recorded pregnancy. In this cohort study, we describe changes in engagement in HIV care before, during, and after pregnancy among women with HIV from the UK Collaborative HIV Cohort (CHIC) study from 25 HIV clinics in the UK with a livebirth reported to the National Surveillance of HIV in Pregnancy and Childhood between Jan 1, 2000, and Dec 31, 2017. To investigate whether changes were specific to HIV, we compared these changes to those over equivalent periods among non-pregnant women with HIV in the UK CHIC study matched for ethnicity, year of conception, age, CD4 cell count, viral suppression, and antiretroviral therapy use. Analyses were via logistic regression using generalised estimated equations with an interaction between case-control status (pregnant women vs non-pregnant women) and pregnancy or pseudo pregnancy (for non-pregnant women) stage. 1116 matched pairs of pregnant and non-pregnant women were included (median age 34 years [IQR 30-38], 80·1% Black African, 12·5% white). 69 330 person-months of follow-up were recorded, 25 412 in the before stage, 18 897 during, and 25 021 after pregnancy or pseudo pregnancy stages. Among pregnant women, the proportion of time engaged in care increased during pregnancy (8477 [90·5%] of 9371 person-months) and after pregnancy (10 501 [84·6%] of 12 407), compared with before pregnancy (9979 [78·5%] of 12 707). Among non-pregnant women in the control group, engagement in HIV care remained stable across the three equivalent stages (9688 [76·3%] of 12 705 person-months before pseudo pregnancy; 7463 [78·3%] of 9526 during pseudo pregnancy; and 9892 [78·4%] of 12 614 after pseudo pregnancy). The association of engagement in HIV care with pregnancy or pseudo pregnancy stage differed significantly by case-control status (pinteraction<0·0001); the odds of engagement in HIV care were higher during pregnancy (odds ratio [OR] 3·32, 95% CI 2·68-4·12) and after pregnancy (OR 1·49, 1·24-1·79) only among pregnant women, and not among non-pregnant women, when compared with the before pseudo pregnancy stage. Women with HIV and a pregnancy resulting in a livebirth were more likely to engage in HIV care post partum when compared with before pregnancy. A detailed understanding of the reason for this finding could support interventions to maximise engagement in HIV care for all women with HIV. Medical Research Council and National Institute for Health Research.

Differences in HIV clinical outcomes amongst heterosexuals in the United Kingdom by ethnicity.

We investigated differences in clinical outcomes in heterosexual participants, by ethnicity in the UK Collaborative HIV Cohort Study from 2000 to 2017. Cohort analysis. Logistic/proportional hazard regression assessed ethnic group differences in CD4+ cell count at presentation, engagement-in-care, combination antiretroviral therapy (cART) initiation, viral suppression and rebound. Of 12 302 participants [median age: 37 (interquartile range: 31-44) years, 52.5% women, total follow-up: 85 846 person-years], 64.4% were black African, 19.1% white, 6.3% black Caribbean, 3.6% black other, 3.3% South Asian/other Asian and 3.4% other/mixed. CD4+ cell count at presentation amongst participants from non-white groups were lower than the white group. Participants were engaged-in-care for 79.6% of follow-up time; however, black and other/mixed groups were less likely to be engaged-in-care than the white group (adjusted odds ratios vs. white: black African: 0.70 (95% confidence interval (CI) 0.63-0.79], black Caribbean: 0.74 (0.63-0.88), other/mixed: 0.78 (0.62-0.98), black other: 0.81 (0.64-1.02)). Of 8867 who started cART, 79.1% achieved viral suppression, with no differences by ethnicity in cART initiation or viral suppression. Viral rebound (22.2%) was more common in the black other [1.95 (1.37-2.77)], black African [1.85 (1.52-2.24)], black Caribbean [1.73 (1.28-2.33)], South Asian/other Asian [1.35 (0.90-2.03)] and other/mixed [1.09 (0.69-1.71)] groups than in white participants. Heterosexual people from black, Asian and minority ethnic (BAME) groups presented with lower CD4+ cell counts, spent less time engaged-in-care and were more likely to experience viral rebound than white people. Work to understand and address these differences is needed.

Mortality and AIDS-defining events among young people following transition from paediatric to adult HIV care in the UK.

ObjectivesTo investigate risk of AIDS and mortality after transition from paediatric to adult care in a UK cohort of young people with perinatally acquired HIV.MethodsRecords of people aged ≥ 13 years on 31 December 2015 in the UK paediatric HIV cohort (Collaborative HIV Paediatric Study) were linked to those of adults in the UK Collaborative HIV Cohort (CHIC) cohort. We calculated time from transition to a new AIDS event/death, with follow‐up censored at the last visit or 31 December 2015, whichever was the earliest. Cumulative incidence of and risk factors for AIDS/mortality were assessed using Kaplan–Meier and Cox regression.ResultsAt the final paediatric visit, the 474 participants [51% female, 80% black, 60% born outside the UK, median (interquartile range) age at antiretroviral therapy (ART) initiation = 9 (5–13) years] had a median age of 18 (17–19) years and CD4 count of 471 (280–663) cell/μL; 89% were prescribed ART and 60% overall had a viral load ≤ 400 copies/mL. Over median follow‐up in adult care of 3 (2–6) years, 35 (8%) experienced a new AIDS event (n = 25) or death (n = 14) (incidence = 1.8/100 person‐years). In multivariable analyses, lower CD4 count at the last paediatric visit [adjusted hazard ratio = 0.8 (95% confidence interval: 0.7–1.0)/100 cells/μL increment] and AIDS diagnosis in paediatric care [2.7 (1.4–5.5)] were associated with a new AIDS event/mortality in adult care.ConclusionsYoung people with perinatally acquired HIV transitioning to adult care with markers of disease progression in paediatric care experienced poorer outcomes in adult care. Increased investment in multidisciplinary specialized services is required to support this population at high risk of morbidity and mortality.

CD4+:CD8+ T Cell Ratio Normalization and the Development of AIDS Events in People with HIV Starting Antiretroviral Therapy.

We identify factors associated with the normalization of the CD4+:CD8+ T cell ratio among UK Collaborative HIV Cohort study participants, and describe the association of the CD4+ and CD8+ T cell counts and the CD4+:CD8+ T cell ratio, with the risk of new AIDS events among individuals who achieve a suppressed viral load. Participants initiating combination antiretroviral therapy (cART) after 2006 with a CD4+:CD8+ T cell ratio <1, and viral suppression within 6 months were included. Cox proportional hazard models were used to examine associations with ratio normalization (ratio ≥1). Poisson regression models were used to investigate factors associated with the development of AIDS after viral load suppression. A total of 13,178 participants [median age: 37 (interquartile range: 31–44)] were followed for 75,336 person-years. Of the 4,042 (32.9%) who experienced ratio normalization, individuals with a high CD4+ T cell count [>500 vs. ≤200 cells/mm3, adjusted hazard ratio (95% confidence interval): 7.93 (6.97–9.01)], low CD8+ T cell count [>1,150 vs. ≤500 cells/mm3: 0.18 (0.16–0.21)], and low CD4+:CD8+ T cell ratio [>0.8 vs. <0.2: 12.36 (10.41–14.68)] at cART initiation were more likely to experience ratio normalization. Four hundred and nineteen people developed a new AIDS event. Most recent CD4+ T cell count [>500 vs. ≤200 cells/mm3: adjusted rate ratio 0.24 (0.16–0.34)] and CD4+:CD8+ T cell ratio [>0.8 vs. <0.2: 0.33 (0.21–0.52)] were independently associated with a new AIDS event. One third of study participants experienced ratio normalization after starting cART. CD4+ T cell count and CD4+:CD8+ T cell ratio are both individually associated with ratio normalization and the development of new AIDS events after cART.

Associations between baseline characteristics, CD4 cell count response and virological failure on first-line efavirenz + tenofovir + emtricitabine for HIV

ObjectivesThe aim of this study was to investigate associations between baseline characteristics and CD4 cell count response on first-line antiretroviral therapy and risk of virological failure (VF) with or without drug resistance. MethodsWe conducted an analysis of UK Collaborative HIV Cohort data linked to the UK HIV Drug Resistance Database. Inclusion criteria were viral sequence showing no resistance prior to initiation of first-line efavirenz + tenofovir disoproxil fumarate + emtricitabine and virological suppression within 6 months. Outcomes of VF (≥200 copies/mL) with or without drug resistance were assessed using a competing risks approach fitted jointly with a model for CD4 cell count recovery. Hazard ratios for each VF outcome were estimated for baseline CD4 cell count and viral load and characteristics of CD4 cell count response using latent variables on a standard normal scale. ResultsA total of 3640 people were included with 338 VF events; corresponding viral sequences were available in 134 with ≥1 resistance mutation in 36. VF with resistance was associated with lower baseline CD4 (0.30, 0.09–0.62), lower CD4 recovery (0.04, 0.00–0.17) and higher CD4 variability (4.40, 1.22–12.68). A different pattern of associations was observed for VF without resistance, but the strength of these results was less consistent across sensitivity analyses. Cumulative incidence of VF with resistance was estimated to be >2% at 3 years for baseline CD4 ≥350 cells/μL. ConclusionLower baseline CD4 cell count and suboptimal CD4 recovery are associated with VF with drug resistance. People with low CD4 cell count before ART or with suboptimal CD4 recovery on treatment should be a priority for regimens with high genetic barrier to resistance.

Non-disclosed men who have sex with men in UK HIV transmission networks: phylogenetic analysis of surveillance data

Patients who do not disclose their sexuality, including men who do not disclose same-sex behaviour, are difficult to characterise through traditional epidemiological approaches such as interviews. Using a recently developed method to detect large networks of viral sequences from time-resolved trees, we localised non-disclosed men who have sex with men (MSM) in UK transmission networks, gaining crucial insight into the behaviour of this group. For this phylogenetic analysis, we obtained HIV pol sequences from the UK HIV Drug Resistance Database (UKRDB), a central repository for resistance tests done as part of routine clinical care throughout the UK. Sequence data are linked to demographic and clinical data held by the UK Collaborative HIV Cohort study and the national HIV/AIDS reporting system database. Initially, we reconstructed maximum likelihood phylogenies from these sequences, then sequences were selected for time-resolved analysis in BEAST if they were clustered with at least one other sequence at a genetic distance of 4·5% or less with support of at least 90%. We used time-resolved phylogenies to create networks by linking together nodes if sequences shared a common ancestor within the previous 5 years. We identified potential non-disclosed MSM (pnMSM), defined as self-reported heterosexual men who clustered only with men. We measured the network position of pnMSM, including betweenness (a measure of connectedness and importance) and assortativity (the propensity for nodes sharing attributes to link). 14 405 individuals were in the network, including 8452 MSM, 1743 heterosexual women and 1341 heterosexual men. 249 pnMSM were identified (18·6% of all clustered heterosexual men) in the network. pnMSM were more likely to be black African (p<0·0001), less likely to be infected with subtype B (p=0·006), and were slightly older (p=0·002) than the MSM they clustered with. Mean betweenness centrality was lower for pnMSM than for MSM (1·31, 95% CI 0·48-2·15 in pnMSM vs 2·24, 0·98-3·51 in MSM; p=0·002), indicating that pnMSM were in peripheral positions in MSM clusters. Assortativity by risk group was higher than expected (0·037 vs -0·037, p=0·01) signifying that pnMSM were linked to each other. We found that self-reported heterosexual men were more likely to link MSM and heterosexual women than heterosexual women were to link MSM and heterosexual men (Fisher's exact test p=0·0004; OR 2·24) but the number of such transmission chains was small (only 54 in total vs 32 in women). pnMSM are a subgroup distinct from both MSM and from heterosexual men. They are more likely to choose sexual partners who are also pnMSM and might exhibit lower-risk sexual behaviour than MSM (eg, choosing low-risk partners or consistently using condoms). Heterosexual men are the group most likely to be diagnosed with late-stage disease (ie, low CD4 counts) and non-disclosed MSM might put female partners at higher risk than heterosexual men because non-disclosed MSM have male partners. Hence, pnMSM require specific consideration to ensure they are included in public health interventions. National Institutes of Health.

A continuum of HIV care describing mortality and loss to follow-up: a longitudinal cohort study

SummaryBackgroundThe cross-sectional HIV care continuum is widely used to assess the success of HIV care programmes among populations of people with HIV and the potential for ongoing transmission. We aimed to investigate whether a longitudinal continuum, which incorporates loss to follow-up and mortality, might provide further insights about the performance of care programmes.MethodsIn this longitudinal cohort study, we included individuals who entered the UK Collaborative HIV Cohort (CHIC) study between Jan 1, 2000, and Dec 31, 2004, and were linked to the national HIV cohort database (HIV and AIDS Reporting System). For each month during a 10 year follow up period, we classified individuals into one of ten distinct categories according to engagement in care, antiretroviral therapy (ART) use, viral suppression, loss to cohort follow-up and loss to care, and mortality, and assessed the proportion of person-months of follow-up spent in each stage of the continuum. 5 year longitudinal continuums were also constructed for three separate cohorts (baseline years of entry 2000–03, 2004–07, and 2008–09) to compare changes over time.FindingsWe included 12 811 people contributing 1 537 320 person-months in our analysis. During 10 years of follow-up, individuals spent 811 057 (52·8%) of 1 537 320 person-months on ART. Of the 811 057 person-months spent on ART, individuals had a viral load of 200 copies per mL or less for 607 185 (74·9%) person-months. 10 years after cohort entry, 3612 (28·1%) of 12 811 individuals were lost to follow-up, 954 (26·4%) of whom had transferred to a non-CHIC UK clinic for care. By 10 years, 759 (5·9%) of 12 811 participants who entered the cohort had died. Loss to follow-up decreased and the proportion of person-months that individuals spent virally suppressed increased over calendar time.InterpretationLoss to follow-up in HIV care programmes was high and rates of viral suppression were lower than previously reported. Complementary information provided by a longitudinal continuum might highlight areas for intervention along the HIV care pathway, however, transfers outside the cohort must be accounted for.FundingMedical Research Council, UK.

Risk factors and outcomes for the Q151M and T69 insertion HIV-1 resistance mutations in historic UK data

BackgroundThe prevalence of HIV-1 resistance to antiretroviral therapies (ART) has declined in high-income countries over recent years, but drug resistance remains a substantial concern in many low and middle-income countries. The Q151M and T69 insertion (T69i) resistance mutations in the viral reverse transcriptase gene can reduce susceptibility to all nucleoside/tide analogue reverse transcriptase inhibitors, motivating the present study to investigate the risk factors and outcomes associated with these mutations.MethodsWe considered all data in the UK HIV Drug Resistance Database for blood samples obtained in the period 1997–2014. Where available, treatment history and patient outcomes were obtained through linkage to the UK Collaborative HIV Cohort study. A matched case–control approach was used to assess risk factors associated with the appearance of each of the mutations in ART-experienced patients, and survival analysis was used to investigate factors associated with viral suppression. A further analysis using matched controls was performed to investigate the impact of each mutation on survival.ResultsA total of 180 patients with Q151M mutation and 85 with T69i mutation were identified, almost entirely from before 2006. Occurrence of both the Q151M and T69i mutations was strongly associated with cumulative period of virological failure while on ART, and for Q151M there was a particular positive association with use of stavudine and negative association with use of boosted-protease inhibitors. Subsequent viral suppression was negatively associated with viral load at sequencing for both mutations, and for Q151M we found a negative association with didanosine use but a positive association with boosted-protease inhibitor use. The results obtained in these analyses were also consistent with potentially large associations with other drugs. Analyses were inconclusive regarding associations between the mutations and mortality, but mortality was high for patients with low CD4 at detection.ConclusionsThe Q151M and T69i resistance mutations are now very rare in the UK. Our results suggest that good outcomes are possible for people with these mutations. However, in this historic sample, viral load and CD4 at detection were important factors in determining prognosis.

How Durable Is Modern ART

Current antiretroviral therapy (ART) regimens are associated with high rates of HIV suppression, but the durability of the treatment response is not known. Now, investigators from the UK Collaborative HIV Cohort (UK CHIC) Study have reviewed data on more than 16,000 HIV-positive persons initiating ART between January 1998 and May 2013 to investigate the rate of first viral rebound, the factors associated …

Durability of viral suppression with first-line antiretroviral therapy in patients with HIV in the UK: an observational cohort study

SummaryBackgroundThe length of time that people with HIV on antiretroviral therapy (ART) with viral load suppression will be able to continue before developing viral rebound is unknown. We aimed to investigate the rate of first viral rebound in people that have achieved initial suppression with ART, to determine factors associated with viral rebound, and to use these estimates to predict long-term durability of viral suppression.MethodsThe UK Collaborative HIV Cohort (UK CHIC) Study is an ongoing multicentre cohort study that brings together in a standardised format data on people with HIV attending clinics around the UK. We included participants who started ART with three or more drugs and who had achieved viral suppression (≤50 copies per mL) by 9 months after the start of ART (baseline). Viral rebound was defined as the first single viral load of more than 200 copies per mL or treatment interruption (for ≥1 month). We investigated factors associated with viral rebound with Poisson regression. These results were used to calculate the rate of viral rebound according to several key factors, including age, calendar year at start of ART, and time since baseline.ResultsOf the 16 101 people included, 4519 had a first viral rebound over 58 038 person-years (7·8 per 100 person-years, 95% CI 7·6–8·0). Of the 4519 viral rebounds, 3105 (69%) were defined by measurement of a single viral load of more than 200 copies per mL, and 1414 (31%) by a documented treatment interruption. The rate of first viral rebound declined substantially over time until 7 years from baseline. The other factors associated with viral rebound were current age at follow-up and calendar year at ART initiation (p<0·0001) and HIV risk group (p<0·0001); higher pre-ART CD4 count (p=0·0008) and pre-ART viral load (p=0·0003) were associated with viral rebound in the multivariate analysis only. For 1322 (29%) of the 3105 people with observed viral rebound, the next viral load value after rebound was 50 copies per mL or less with no regimen change. For HIV-positive men who have sex with men, our estimates suggest that the probability of first viral rebound reaches a plateau of 1·4% per year after 45 years of age, and 1·0% when accounting for the fact that 29% of viral rebounds are temporary elevations.InterpretationA substantial proportion of people on ART will not have viral rebound over their lifetime, which has implications for people with HIV and the planning of future drug development.FundingUK Medical Research Council.

HIV-1 drug resistance mutations emerging on darunavir therapy in PI-naive and -experienced patients in the UK.

BackgroundDarunavir is considered to have a high genetic barrier to resistance. Most darunavir-associated drug resistance mutations (DRMs) have been identified through correlation of baseline genotype with virological response in clinical trials. However, there is little information on DRMs that are directly selected by darunavir in clinical settings.ObjectivesWe examined darunavir DRMs emerging in clinical practice in the UK.Patients and methodsBaseline and post-exposure protease genotypes were compared for individuals in the UK Collaborative HIV Cohort Study who had received darunavir; analyses were stratified for PI history. A selection analysis was used to compare the evolution of subtype B proteases in darunavir recipients and matched PI-naive controls.ResultsOf 6918 people who had received darunavir, 386 had resistance tests pre- and post-exposure. Overall, 2.8% (11/386) of these participants developed emergent darunavir DRMs. The prevalence of baseline DRMs was 1.0% (2/198) among PI-naive participants and 13.8% (26/188) among PI-experienced participants. Emergent DRMs developed in 2.0% of the PI-naive group (4 mutations) and 3.7% of the PI-experienced group (12 mutations). Codon 77 was positively selected in the PI-naive darunavir cases, but not in the control group.ConclusionsOur findings suggest that although emergent darunavir resistance is rare, it may be more common among PI-experienced patients than those who are PI-naive. Further investigation is required to explore whether codon 77 is a novel site involved in darunavir susceptibility.

Development and application of a new measure of engagement in out-patient HIV care.

ObjectivesCommonly used measures of engagement in HIV care do not take into account that the frequency of attendance is related to changes in treatment and health status. This study developed a new measure of engagement in care (EIC) incorporating clinical factors.MethodsWe conducted semi‐structured interviews with eight HIV physicians to identify factors associated with the timing of patients' next scheduled appointments. These factors informed the development of an algorithm to classify each month of follow‐up as “in care” (on or before the time of the next expected attendance) or “out of care” (after the time of the next expected attendance). The EIC algorithm was applied to data from the UK Collaborative HIV Cohort (UK CHIC) study, a large clinical cohort study.ResultsThe interviews indicated that time to next appointment varied depending on psychosocial and physical comorbidities, and clinical factors (time since diagnosis, AIDS diagnosis, treatment status, CD4 count and viral load). The resulting EIC algorithm was applied to 44 432 patients; 83.9% of the 3 021 224 person‐months were “in care”. Greater EIC was independently associated with older age, white ethnicity, HIV acquisition through sex between men, current use of antiretroviral therapy (ART), a higher nadir CD4 count, later calendar year and being seen at the clinic for the first time within the last year.ConclusionsThis algorithm describing engagement in HIV care incorporates a time‐updated measure of patients' treatment and health status. It adds to the options available for measuring this key performance indicator.

Predicting virological decay in patients starting combination antiretroviral therapy.

Objective:Model trajectories of viral load measurements from time of starting combination antiretroviral therapy (cART), and use the model to predict whether patients will achieve suppressed viral load (≤200 copies/ml) within 6-months of starting cART.Design:Prospective cohort study including HIV-positive adults (UK Collaborative HIV Cohort Study).Methods:Eligible patients were antiretroviral naive and started cART after 1997. Random effects models were used to estimate viral load trends. Patients were randomly selected to form a validation dataset with those remaining used to fit the model. We evaluated predictions of suppression using indices of diagnostic test performance.Results:Of 9562 eligible patients 6435 were used to fit the model and 3127 for validation. Mean log10 viral load trajectories declined rapidly during the first 2 weeks post-cART, moderately between 2 weeks and 3 months, and more slowly thereafter. Higher pretreatment viral load predicted steeper declines, whereas older age, white ethnicity, and boosted protease inhibitor/non-nucleoside reverse transcriptase inhibitors based cART-regimen predicted a steeper decline from 3 months onwards. Specificity of predictions and the diagnostic odds ratio substantially improved when predictions were based on viral load measurements up to the 4-month visit compared with the 2 or 3-month visits. Diagnostic performance improved when suppression was defined by two consecutive suppressed viral loads compared with one.Conclusions:Viral load measurements can be used to predict if a patient will be suppressed by 6-month post-cART. Graphical presentations of this information could help clinicians decide the optimum time to switch treatment regimen during the first months of cART.

The risk of viral rebound in the year after delivery in women remaining on antiretroviral therapy.

Objective:The objective of this study is to assess the risk of viral rebound in postpartum women on suppressive combination antiretroviral therapy (cART).Methods:Using data from the UK Collaborative HIV Cohort (UK CHIC) study and the UK and Ireland National Study of HIV in Pregnancy and Childhood (NSHPC), women with HIV-RNA 50 copies/ml or less at delivery in 2006–2011, who started life-long cART during pregnancy (n = 321) or conceived on cART (n = 618), were matched by age, duration on cART and time period, with at least one control (non-postpartum). The cumulative probability of viral rebound (HIV-RNA >200 copies/ml) was assessed by Kaplan–Meier analysis; adjusted hazard ratios (aHRs) for the 0–3 and 3–12 months postdelivery (cases)/pseudo-delivery (controls) were calculated in Cox proportional hazards models.Results:In postpartum women who conceived on cART, 5.9% [95% confidence interval (95% CI) 4.0–7.7] experienced viral rebound by 3 months, and 2.2% (1.4–3.0%) of their controls. The risk of viral rebound was higher in postpartum women than in controls during the first 3 months [aHR 2.63 (1.58–4.39)] but not during the 3–12 months postdelivery/pseudo-delivery. In postpartum women who started cART during pregnancy, 27% (22–32%) experienced viral rebound by 3 months, and 3.0% (1.6–4.4%) of their controls. The risk of viral rebound was higher in postpartum women than in controls during both postdelivery/pseudo-delivery periods [<3 months: aHR 6.63 (3.58–12.29); 3–12 months: aHR 4.05 (2.03–8.09)].Conclusion:In women on suppressive cART, the risk of viral rebound is increased following delivery, especially in the first 3 months, which may be related to reduced adherence, indicating the need for additional adherence support for postpartum women.

Pregnancy is associated with elevation of liver enzymes in HIV-positive women on antiretroviral therapy.

Objective:The objective of this study is to assess whether pregnancy is associated with an increased risk of liver enzyme elevation (LEE) and severe LEE in HIV-positive women on antiretroviral therapy (ART).Design:Two observational studies: the UK Collaborative HIV Cohort (UK CHIC) study and the UK and Ireland National Study of HIV in Pregnancy and Childhood (NSHPC).Methods:Combined data from UK CHIC and NSHPC were used to identify factors associated with LEE (grade 1–4) and severe LEE (grade 3–4). Women starting ART in 2000–2012 were included irrespective of pregnancy status. Cox proportional hazards were used to assess fixed and time-dependent covariates including pregnancy status, CD4+ cell count, drug regimen and hepatitis B virus/hepatitis C virus (HBV/HCV) coinfection.Results:One-quarter (25.7%, 982/3815) of women were pregnant during follow-up, 14.2% (n = 541) when starting ART. The rate of LEE was 14.5/100 person-years in and 6.0/100 person-years outside of pregnancy. The rate of severe LEE was 3.9/100 person-years in and 0.6/100 person-years outside of pregnancy. The risk of LEE and severe LEE was increased during pregnancy [LEE: adjusted hazard ratio (aHR) 1.66 (1.31–2.09); severe LEE: aHR 3.57 (2.30–5.54)], including in secondary analyses excluding 541 women pregnant when starting ART. Other factors associated with LEE and severe LEE included lower CD4+ cell count (<250 cells/μl), HBV/HCV coinfection and calendar year.Conclusion:Although few women developed severe LEE, this study provides further evidence that pregnancy is associated with an increased risk of LEE and severe LEE, reinforcing the need for regular monitoring of liver biomarkers during pregnancy.

Rate of viral load failure over time in people on ART in the UK Collaborative HIV Cohort (CHIC) study.

IntroductionMost people achieve and maintain viral load (VL) suppression on first-line antiretroviral therapy (ART) but for a minority this does not happen. It is unclear whether those who have maintained VL suppression for several years will be able to continue to do so, or if rates of VL failure – due to poor adherence, ART interruption and/or resistance – remain at appreciable levels.MethodsEligible participants were ART-naïve and started treatment after 1st January 2000, with ≥3 antiretrovirals and ≥9 months follow-up. VL failure was defined as failure to achieve VL suppression (≤50 copies/mL) by 9 months on ART or a single VL >200 copies/mL after 9 months after start of ART. Kaplan-Meier estimates were used to examine the cumulative probability of experiencing a VL >200 copies/mL over time, irrespective of treatment interruption (Figure 1). Follow-up was censored at last VL assessment but not at treatment interruption. In a sensitivity analysis, VL failure was instead defined as two consecutive VL >1000 copies/mL.ResultsA total of 13,556 participants were included. Median (IQR) age at start of ART was 37 (32–43), median follow-up 4.1 (2.3–6.7) years, pre-ART VL 71,400 (17,400–221,900) copies/mL and pre-ART CD4 count 204 (110–290) cells/mm3. Fifty-one percent were white, 71% male and 50% MSM. Of which, 5,351 (39%) participants experienced a VL >200 copies/mL. In sub-groups of participants the proportion experiencing a VL >200 copies/mL by one year after start of ART were: <50 years 22%, ≥50 years 17%, men 20%, women 26%, MSM 19%, black heterosexuals 23%, white heterosexuals 26% and other 23%. The median time to VL >200 copies/ml was 8 years. In sensitivity analyses based on 12,811 participants, 4274 (33%) experienced two consecutive VL >1000 copies/mL. Table 1 presents the rate of experiencing a VL >200 copies/mL (two consecutive VL >1000 copies/mL) by time since start of ART. The rate of VL >200 copies/mL declines over time, from 30 per 100 person-years after up to two years after ART, to two per 100 person-years after up to 11.5 years after ART. A sum of 2,047 (15%) participants stopped ART at some point (10, 14 and 17% had stopped ART by 1, 3, and 5 years, respectively). ConclusionsAlthough resistance will often not be present and, even if present, several drug options will likely remain, first occurrence of VL > 200 copies/mL after having attained viral suppression continues to occur after 10 years on ART.