Colette Smith

Timing of initiation of antiretroviral therapy in AIDS-free HIV-1-infected patients: a collaborative analysis of 18 HIV cohort studies

Summary Background The CD4 cell count at which combination antiretroviral therapy should be started is a central, unresolved issue in the care of HIV-1-infected patients. In the absence of randomised trials, we examined this question in prospective cohort studies. Methods We analysed data from 18 cohort studies of patients with HIV. Antiretroviral-naive patients from 15 of these studies were eligible for inclusion if they had started combination antiretroviral therapy (while AIDS-free, with a CD4 cell count less than 550 cells per μL, and with no history of injecting drug use) on or after Jan 1, 1998. We used data from patients followed up in seven of the cohorts in the era before the introduction of combination therapy (1989–95) to estimate distributions of lead times (from the first CD4 cell count measurement in an upper range to the upper threshold of a lower range) and unseen AIDS and death events (occurring before the upper threshold of a lower CD4 cell count range is reached) in the absence of treatment. These estimations were used to impute completed datasets in which lead times and unseen AIDS and death events were added to data for treated patients in deferred therapy groups. We compared the effect of deferred initiation of combination therapy with immediate initiation on rates of AIDS and death, and on death alone, in adjacent CD4 cell count ranges of width 100 cells per μL. Findings Data were obtained for 21 247 patients who were followed up during the era before the introduction of combination therapy and 24 444 patients who were followed up from the start of treatment. Deferring combination therapy until a CD4 cell count of 251–350 cells per μL was associated with higher rates of AIDS and death than starting therapy in the range 351–450 cells per μL (hazard ratio [HR] 1·28, 95% CI 1·04–1·57). The adverse effect of deferring treatment increased with decreasing CD4 cell count threshold. Deferred initiation of combination therapy was also associated with higher mortality rates, although effects on mortality were less marked than effects on AIDS and death (HR 1·13, 0·80–1·60, for deferred initiation of treatment at CD4 cell count 251–350 cells per μL compared with initiation at 351–450 cells per μL). Interpretation Our results suggest that 350 cells per μL should be the minimum threshold for initiation of antiretroviral therapy, and should help to guide physicians and patients in deciding when to start treatment. Funding UK Medical Research Council.

Factors associated with specific causes of death amongst HIV-positive individuals in the D:A:D Study.

Objective:To investigate any emerging trends in causes of death amongst HIV-positive individuals in the current cART era, and to investigate the factors associated with each specific cause of death. Design:An observational multicentre cohort study. Methods:All HIV-positive individuals included in one of the cohorts in the Data Collection on Adverse Events of Anti-HIV drugs (D:A:D) Study were included. The association between HIV-specific and non HIV-specific risk factors and death were studied using multivariable Poisson regression. Results:We observed 2482 deaths in 180 176 person-years (PY) on 33 308 individuals [rate/1000 PY = 13.8 (95% CI 13.2–14.3)]. Primary causes of death were: AIDS (n = 743; rate/1000 PY = 4.12), liver-related (341; 1.89), CVD-related (289; 1.60), non-AIDS malignancy (286; 1.59). The overall rate of death fell from 16.9 in 1999/2000 to 9.6/ 1000 PY in 2007/2008. Smoking was associated with CVD and non-AIDS cancers, HBV and HCV co-infection with liver-related deaths, and hypertension with liver-related and CVD deaths. Diabetes was a risk factor for all specific causes of death except non-AIDS cancers, and higher current HIV RNA for AIDS-related deaths. Lower CD4 cell counts were associated with a higher risk of death from all specific causes of death. Conclusion:Multiple potentially modifiable traditional and HIV-specific risk factors for death of HIV-infected persons were identified. The maximum reduction in mortality in HIV-infected populations will require that each of these factors be appropriately addressed. No trends in terms of emerging causes of unexpected deaths were observed, although monitoring will continue.

Cytomegalovirus glycoprotein-B vaccine with MF59 adjuvant in transplant recipients: a phase 2 randomised placebo-controlled trial

Summary Background Cytomegalovirus end-organ disease can be prevented by giving ganciclovir when viraemia is detected in allograft recipients. Values of viral load correlate with development of end-organ disease and are moderated by pre-existing natural immunity. Our aim was to determine whether vaccine-induced immunity could do likewise. Methods We undertook a phase-2 randomised placebo controlled trial in adults awaiting kidney or liver transplantation at the Royal Free Hospital, London, UK. Exclusion criteria were pregnancy, receipt of blood products (except albumin) in the previous 3 months, and simultaneous multiorgan transplantation. 70 patients seronegative and 70 seropositive for cytomegalovirus were randomly assigned from a scratch-off randomisation code in a 1:1 ratio to receive either cytomegalovirus glycoprotein-B vaccine with MF59 adjuvant or placebo, each given at baseline, 1 month and 6 months later. If a patient was transplanted, no further vaccinations were given and serial blood samples were tested for cytomegalovirus DNA by real-time quantitative PCR (rtqPCR). Any patient with one blood sample containing more than 3000 cytomegalovirus genomes per mL received ganciclovir until two consecutive undetectable cytomegalovirus DNA measurements. Safety and immunogenicity were coprimary endpoints and were assessed by intention to treat in patients who received at least one dose of vaccine or placebo. This trial is registered with ClinicalTrials.gov, NCT00299260. Findings 67 patients received vaccine and 73 placebo, all of whom were evaluable. Glycoprotein-B antibody titres were significantly increased in both seronegative (geometric mean titre 12 537 (95% CI 6593–23 840) versus 86 (63–118) in recipients of placebo recipients; p<0·0001) and seropositive (118 395; 64 503–217 272) versus 24 682 (17 909–34 017); p<0·0001) recipients of vaccine. In those who developed viraemia after transplantation, glycoprotein-B antibody titres correlated inversely with duration of viraemia (p=0·0022). In the seronegative patients with seropositive donors, the duration of viraemia (p=0·0480) and number of days of ganciclovir treatment (p=0·0287) were reduced in vaccine recipients. Interpretation Although cytomegalovirus disease occurs in the context of suppressed cell-mediated immunity post-transplantation, humoral immunity has a role in reduction of cytomegalovirus viraemia. Vaccines containing cytomegalovirus glycoprotein B merit further assessment in transplant recipients. Funding National Institute of Allergy and Infectious Diseases, Grant R01AI051355 and Wellcome Trust, Grant 078332. Sponsor: University College London (UCL).

Association between antiretroviral exposure and renal impairment among HIV-positive persons with normal baseline renal function: the D:A:D study.

BACKGROUND Several antiretroviral agents (ARVs) are associated with chronic renal impairment, but the extent of such adverse events among human immunodeficiency virus (HIV)-positive persons with initially normal renal function is unknown. METHODS D:A:D study participants with an estimated glomerular filtration rate (eGFR) of ≥ 90 mL/min after 1 January 2004 were followed until they had a confirmed eGFR of ≤ 70 mL/min (the threshold below which we hypothesized that renal interventions may begin to occur) or ≤ 60 mL/min (a value indicative of moderately severe chronic kidney disease [CKD]) or until the last eGFR measurement during follow-up. An eGFR was considered confirmed if it was detected at 2 consecutive measurements ≥ 3 months apart. Predictors and eGFR-related ARV discontinuations were identified using Poisson regression. RESULTS Of 22 603 persons, 468 (2.1%) experienced a confirmed eGFR of ≤ 70 mL/min (incidence rate, 4.78 cases/1000 person-years of follow-up [95% confidence interval {CI}, 4.35-5.22]) and 131 (0.6%) experienced CKD (incidence rate, 1.33 cases/1000 person-years of follow-up [95% CI, 1.10-1.56]) during a median follow-up duration of 4.5 years (interquartile range [IQR], 2.7-6.1 years). A current eGFR of 60-70 mL/min caused significantly higher rates of discontinuation of tenofovir (adjusted incidence rate ratio [aIRR], 1.72 [95% CI, 1.38-2.14]) but not other ARVs compared with a current eGFR of ≥ 90 mL/min. Cumulative tenofovir use (aIRR, 1.18/year [95% CI, 1.12-1.25]) and ritonavir-boosted atazanavir use (aIRR, 1.19/year [95% CI, 1.09-1.32]) were independent predictors of a confirmed eGFR of ≤ 70 but were not significant predictors of CKD whereas ritonavir-boosted lopinavir use was a significant predictor for both end points (aIRR, 1.11/year [95% CI, 1.05-1.17] and 1.22/year [95% CI, 1.16-1.28], respectively). Associations were unaffected by censoring for concomitant ARV use but diminished after discontinuation of these ARVs. CONCLUSIONS Tenofovir, ritonavir-boosted atazanavir, and ritonavir-boosted lopinavir use were independent predictors of chronic renal impairment in HIV-positive persons without preexisting renal impairment. Increased tenofovir discontinuation rates with decreasing eGFR may have prevented further deteriorations. After discontinuation, the ARV-associated incidence rates decreased.

Plasma HIV-1 RNA Detection Below 50 Copies/mL and Risk of Virologic Rebound in Patients Receiving Highly Active Antiretroviral Therapy

BACKGROUND Plasma human immunodeficiency virus type 1 (HIV-1) RNA suppression <50 copies/mL is regarded as the optimal outcome of highly active antiretroviral therapy (HAART). Current viral load (VL) assays show increased sensitivity, but the significance of RNA detection <50 copies/mL is unclear. METHODS This study investigated the virologic outcomes of 1247 patients with VL <50 copies/mL at an arbitrary time point during HAART (= T0), according to whether the actual, unreported (T0)VL was 40-49 copies/mL, RNA detected <40 copies/mL (RNA(+)), or RNA not detected (RNA(-)), as measured by the Abbott Real Time assay. Predictors of rebound >50 and >400 copies/mL over 12 months following T0 were analyzed with Cox proportional hazards models incorporating the (T0)VL and demographic and clinical data. RESULTS Rebound rates >50 copies/mL were 34.2% for (T0)VL 40-49 copies/mL, 11.3% for RNA(+), and 4.0% for RNA(-); rebound rates >400 copies/mL were 13.0%, 3.8%, and 1.2%, respectively. The adjusted hazard ratios for rebound >50 copies/mL were 4.67 (95% confidence interval, 2.91-7.47; P < .0001) and 1.97 (1.25-3.11; P < .0001) with (T0)VL 40-49 copies/mL and RNA(+), respectively, relative to RNA(-), and 6.91 (2.90-16.47; P < .0001) and 2.88 (1.24-6.69; P < .0001), respectively, for rebound >400 copies/mL. The association was independent of adherence levels. CONCLUSIONS In treated patients monitored by RealTime, a VL of 40-49 copies/mL and, to a lesser extent, RNA detection <40 copies/mL predict rebound >50 and >400 copies/mL independently of other recognized determinants. The goal of HAART may need to be revised to a lower cutoff than 50 copies/mL.

Smoking and life expectancy among HIV-infected individuals on antiretroviral therapy in Europe and North America

Background:Cardiovascular disease and non-AIDS malignancies have become major causes of death among HIV-infected individuals. The relative impact of lifestyle and HIV-related factors are debated. Methods:We estimated associations of smoking with mortality more than 1 year after antiretroviral therapy (ART) initiation among HIV-infected individuals enrolled in European and North American cohorts. IDUs were excluded. Causes of death were assigned using standardized procedures. We used abridged life tables to estimate life expectancies. Life-years lost to HIV were estimated by comparison with the French background population. Results:Among 17 995 HIV-infected individuals followed for 79 760 person-years, the proportion of smokers was 60%. The mortality rate ratio (MRR) comparing smokers with nonsmokers was 1.94 [95% confidence interval (95% CI) 1.56–2.41]. The MRRs comparing current and previous smokers with never smokers were 1.70 (95% CI 1.23–2.34) and 0.92 (95% CI 0.64–1.34), respectively. Smokers had substantially higher mortality from cardiovascular disease, non-AIDS malignancies than nonsmokers [MRR 6.28 (95% CI 2.19–18.0) and 2.67 (95% CI 1.60–4.46), respectively]. Among 35-year-old HIV-infected men, the loss of life-years associated with smoking and HIV was 7.9 (95% CI 7.1–8.7) and 5.9 (95% CI 4.9–6.9), respectively. The life expectancy of virally suppressed, never-smokers was 43.5 years (95% CI 41.7–45.3), compared with 44.4 years among 35-year-old men in the background population. Excess MRRs/1000 person-years associated with smoking increased from 0.6 (95% CI –1.3 to 2.6) at age 35 to 43.6 (95% CI 37.9–49.3) at age at least 65 years. Conclusion:Well treated HIV-infected individuals may lose more life years through smoking than through HIV. Excess mortality associated with smoking increases markedly with age. Therefore, increases in smoking-related mortality can be expected as the treated HIV-infected population ages. Interventions for smoking cessation should be prioritized.

Cytomegalovirus Replication Kinetics in Solid Organ Transplant Recipients Managed by Preemptive Therapy

After allotransplantation, cytomegalovirus (CMV) may be transmitted from the donor organ, giving rise to primary infection in a CMV negative recipient or reinfection in one who is CMV positive. In addition, latent CMV may reactivate in a CMV positive recipient. In this study, serial blood samples from 689 kidney or liver transplant recipients were tested for CMV DNA by quantitative PCR. CMV was managed using preemptive antiviral therapy and no patient received antiviral prophylaxis. Dynamic and quantitative measures of viremia and treatment were assessed. Median peak viral load, duration of viremia and duration of treatment were highest during primary infection, followed by reinfection then reactivation. In patients who experienced a second episode of viremia, the viral replication rate was significantly slower than in the first episode. Our data provide a clear demonstration of the immune control of CMV in immunosuppressed patients and emphasize the effectiveness of the preemptive approach for prevention of CMV syndrome and end organ disease. Overall, our findings provide quantitative biomarkers which can be used in pharmacodynamic assessments of the ability of novel CMV vaccines or antiviral drugs to reduce or even interrupt such transmission.

Polyfunctional Cytomegalovirus-Specific CD4+ and pp65 CD8+ T Cells Protect Against High-Level Replication After Liver Transplantation

To determine whether polyfunctional CD4+ T‐cell responses coupled with CD8+ T‐cell responses against human cytomegalovirus (HCMV) are key to the control of HCMV replication we prospectively analyzed 29 liver transplant recipients for CD4+ T‐cell responses against soluble HCMV antigen, pp65 and IE1 proteins, CD8+ T‐cell responses against pp65 and IE1 proteins and a range of T helper (Th) 1 and Th2 cytokines. Eleven patients (38%) developed HCMV DNAemia at a median of 21 days post‐liver transplantation (range 17–31 days). There was a significantly lower frequency and absolute number of total HCMV CD4+ T cells producing IFNγ, IFNγ+IL2 and IL2 and pp65‐CD8+ T cells producing IFNγ in patients with DNAemia. The quantities of Th1 and Th2 cytokines present during the first 20 days posttransplant were not predictive of DNAemia. Cut‐off levels during the first 20 days posttransplant of 0.1% of lysate stimulated CD4+ T cells producing IL2, and pp65‐CD8+ T cells producing IFNγ above 0.4% had positive and negative predictive values for DNAemia of 54% and 100% and 50% and 92%, respectively. Measuring polyfunctional CD4+ T cells against HCMV early posttransplant may allow targeted intervention to minimize the occurrence and acute and long‐term consequences of HCMV replication.

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with ≥3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR ≤ 60 ml/min/1.73 m2. Poisson regression was used to develop a risk score, externally validated on two independent cohorts. In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7–6.7; median follow-up 6.1 y, range 0.3–9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was −2 (interquartile range –4 to 2). There was a 1:393 chance of developing CKD in the next 5 y in the low risk group (risk score < 0, 33 events), rising to 1:47 and 1:6 in the medium (risk score 0–4, 103 events) and high risk groups (risk score ≥ 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166–3,367); NNTH was 202 (95% CI 159–278) and 21 (95% CI 19–23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506–1462), 88 (95% CI 69–121), and 9 (95% CI 8–10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3–12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6–8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.

An updated prediction model of the global risk of cardiovascular disease in HIV-positive persons, the Data-collection on Adverse Effects of Anti-HIV Drugs (D:A:D) Study

Background With the aging of the population living with HIV, the absolute risk of cardiovascular disease (CVD) is increasing. There is a need to further facilitate the identification of persons at elevated risk in routine practice. Methods and results Prospective information was collected on 32,663 HIV-positive persons from 20 countries in Europe and Australia, who were free of CVD at entry into the Data-collection on Adverse Effects of Anti-HIV Drugs (D:A:D) study. Cox regression models (full and reduced) were developed that predict the risk of a global CVD endpoint. The predictive performance of the D:A:D models were compared with a recent CVD prediction model from the Framingham study, which was assessed recalibrated to the D:A:D dataset. A total of 1010 CVD events occurred during 186,364.5 person-years. The full D:A:D CVD prediction model included age, gender, systolic blood pressure, smoking status, family history of CVD, diabetes, total cholesterol, high-density lipoprotein, CD4 lymphocyte count, cumulative exposure to protease- and nucleoside reverse transcriptase-inhibitors, and current use of abacavir. A reduced model omitted antiretroviral therapies. The D:A:D models statistically significantly predicted risk more accurately than the recalibrated Framingham model (Harrell’s c-statistic of 0.791, 0.783 and 0.766 for the D:A:D full, D:A:D reduced, and Framingham models respectively; p < 0.001). The D:A:D models also more accurately predicted five-year CVD-risk for key prognostic subgroups. Conclusions An updated, easily recalibrated, global CVD-risk equation tailored to HIV-positive persons was developed using routinely collected CVD risk parameters and incorporating markers on immune function (CD4 lymphocyte count), and exposure to antiretroviral therapies. The estimated CVD risk can be used to quantify risk and to guide preventive care.