Clinical progression and virological failure on highly active antiretroviral therapy in HIV-1 patients: a prospective cohort study. Swiss HIV Cohort Study

Early antiretroviral therapy during primary HIV-1 infection results in a transient reduction of the viral setpoint upon treatment interruption

Background

Long-term benefits of combination antiretroviral therapy (cART) initiation during primary HIV-1 infection are debated.

Methods

The evolution of plasma HIV-RNA (432 measurements) and cell-associated HIV-DNA (325 measurements) after cessation of cART (median exposure 18 months) was described for 33 participants from the Zurich Primary HIV Infection Study using linear regression and compared with 545 measurements from 79 untreated controls with clinically diagnosed primary HIV infection, respectively a known date for seroconversion.

Results

On average, early treated individuals were followed for 37 months (median) after cART cessation; controls had 34 months of pre-cART follow-up. HIV-RNA levels one year after cART interruption were −0.8 log₁₀ copies/mL [95% confidence interval −1.2;−0.4] lower in early treated patients compared with controls, but this difference was no longer statistically significant by year three of follow-up (−0.3 [−0.9; 0.3]). Mean HIV-DNA levels rebounded from 2 log₁₀ copies [1.8; 2.3] on cART to a stable plateau of 2.7 log₁₀ copies [2.5; 3.0] attained 1 year after therapy stop, which was not significantly different from cross-sectional measurements of 9 untreated members of the control group (2.8 log₁₀ copies [2.5; 3.1]).

Conclusions

The rebound dynamics of viral markers after therapy cessation suggest that early cART may indeed limit reservoir size of latently infected cells, but that much of the initial benefits are only transient. Owing to the non-randomized study design the observed treatment effects must be interpreted with caution.

Interplay between single resistance-associated mutations in the HIV-1 protease and viral infectivity, protease activity, and inhibitor sensitivity

Resistance-associated mutations in the HIV-1 protease modify viral fitness through changes in the catalytic activity and altered binding affinity for substrates and inhibitors. In this report, we examine the effects of 31 mutations at 26 amino acid positions in protease to determine their impact on infectivity and protease inhibitor sensitivity. We found that primary resistance mutations individually decrease fitness and generally increase sensitivity to protease inhibitors, indicating that reduced virion-associated protease activity reduces virion infectivity and the reduced level of per virion protease activity is then more easily titrated by a protease inhibitor. Conversely, mutations at more variable positions (compensatory mutations) confer low-level decreases in sensitivity to all protease inhibitors with little effect on infectivity. We found significant differences in the observed effect on infectivity with a pseudotype virus assay that requires the protease to cleave the cytoplasmic tail of the amphotropic murine leukemia virus (MuLV) Env protein. Additionally, we were able to mimic the fitness loss associated with resistance mutations by directly reducing the level of virion-associated protease activity. Virions containing 50% of a D25A mutant protease were 3- to 5-fold more sensitive to protease inhibitors. This level of reduction in protease activity also resulted in a 2-fold increase in sensitivity to nonnucleoside inhibitors of reverse transcriptase and a similar increase in sensitivity to zidovudine (AZT), indicating a pleiotropic effect associated with reduced protease activity. These results highlight the interplay between enzyme activity, viral fitness, and inhibitor mechanism and sensitivity in the closed system of the viral replication complex.

Incidence of HIV-1 drug resistance among antiretroviral treatment-naive individuals starting modern therapy combinations

BACKGROUND

Estimates of drug resistance incidence to modern first-line combination antiretroviral therapies against human immunodeficiency virus (HIV) type 1 are complicated by limited availability of genotypic drug resistance tests (GRTs) and uncertain timing of resistance emergence.

METHODS

Five first-line combinations were studied (all paired with lamivudine or emtricitabine): efavirenz (EFV) plus zidovudine (AZT) (n = 524); EFV plus tenofovir (TDF) (n = 615); lopinavir (LPV) plus AZT (n = 573); LPV plus TDF (n = 301); and ritonavir-boosted atazanavir (ATZ/r) plus TDF (n = 250). Virological treatment outcomes were classified into 3 risk strata for emergence of resistance, based on whether undetectable HIV RNA levels were maintained during therapy and, if not, whether viral loads were >500 copies/mL during treatment. Probabilities for presence of resistance mutations were estimated from GRTs (n = 2876) according to risk stratum and therapy received at time of testing. On the basis of these data, events of resistance emergence were imputed for each individual and were assessed using survival analysis. Imputation was repeated 100 times, and results were summarized by median values (2.5th-97.5th percentile range).

RESULTS

Six years after treatment initiation, EFV plus AZT showed the highest cumulative resistance incidence (16%) of all regimens (<11%). Confounder-adjusted Cox regression confirmed that first-line EFV plus AZT (reference) was associated with a higher median hazard for resistance emergence, compared with other treatments: EFV plus TDF (hazard ratio [HR], 0.57; range, 0.42-0.76), LPV plus AZT (HR, 0.63; range, 0.45-0.89), LPV plus TDF (HR, 0.55; range, 0.33-0.83), ATZ/r plus TDF (HR, 0.43; range, 0.17-0.83). Two-thirds of resistance events were associated with detectable HIV RNA level ≤500 copies/mL during treatment, and only one-third with virological failure (HIV RNA level, >500 copies/mL).

CONCLUSIONS

The inclusion of TDF instead of AZT and ATZ/r was correlated with lower rates of resistance emergence, most likely because of improved tolerability and pharmacokinetics resulting from a once-daily dosage.

Effect of early antiretroviral therapy during primary HIV-1 infection on cell-associated HIV-1 DNA and plasma HIV-1 RNA

BACKGROUND

Early initiation of combination antiretroviral therapy (ART) during primary HIV-1 infection may prevent the establishment of large viral reservoirs, possibly resulting in improved control of plasma viraemia rebound after ART cessation.

METHODS

Levels of cell-associated HIV-1 DNA and plasma HIV-1 RNA were measured longitudinally in 32 acutely and recently infected patients, who started ART ≤120 days after the estimated date of infection, and interrupted ART after 18 months (median) of continuous therapy. Averages of HIV-1 DNA and RNA concentrations present in blood 30-365 days after therapy interruption (median duration 300 days, range 195-358) were compared between patients who started ART ≤60 days after the estimated date of infection (early starters), those who started between 61 and 120 days (later starters), and, for HIV-1 RNA only, with 89 untreated participants of the Swiss HIV Cohort Study with documented seroconversion and longitudinal measurements collected 90-455 days after the first positive HIV test.

RESULTS

In early ART starters, average levels of plasma HIV-1 RNA and cell-associated HIV-1 DNA after treatment interruption were 1 log(10) (P=0.008) and 0.4 log(10) (P=0.03) lower compared with later starters. Average post-treatment plasma HIV-1 RNA levels in early starters were significantly lower, respectively, compared with untreated controls (-1.2 log(10); P<0.0004).

CONCLUSIONS

Early treatment initiation within 2 months after HIV infection compared with later therapy initiation resulted in reduced levels of plasma viraemia and proviral HIV-1 DNA for ≥1 year after subsequent ART cessation. Plasma HIV-1 RNA levels in early starters were also significantly lower than in untreated controls.

Improved virological outcome in White patients infected with HIV-1 non-B subtypes compared to subtype B

BACKGROUND

Antiretroviral compounds have been predominantly studied in human immunodeficiency virus type 1 (HIV-1) subtype B, but only ~10% of infections worldwide are caused by this subtype. The analysis of the impact of different HIV subtypes on treatment outcome is important.

METHODS

The effect of HIV-1 subtype B and non-B on the time to virological failure while taking combination antiretroviral therapy (cART) was analyzed. Other studies that have addressed this question were limited by the strong correlation between subtype and ethnicity. Our analysis was restricted to white patients from the Swiss HIV Cohort Study who started cART between 1996 and 2009. Cox regression models were performed; adjusted for age, sex, transmission category, first cART, baseline CD4 cell counts, and HIV RNA levels; and stratified for previous mono/dual nucleoside reverse-transcriptase inhibitor treatment.

RESULTS

Included in our study were 4729 patients infected with subtype B and 539 with non-B subtypes. The most prevalent non-B subtypes were CRF02_AG (23.8%), A (23.4%), C (12.8%), and CRF01_AE (12.6%). The incidence of virological failure was higher in patients with subtype B (4.3 failures/100 person-years; 95% confidence interval [CI], 4.0-4.5]) compared with non-B (1.8 failures/100 person-years; 95% CI, 1.4-2.4). Cox regression models confirmed that patients infected with non-B subtypes had a lower risk of virological failure than those infected with subtype B (univariable hazard ratio [HR], 0.39 [95% CI, .30-.52; P < .001]; multivariable HR, 0.68 [95% CI, .51-.91; P = .009]). In particular, subtypes A and CRF02_AG revealed improved outcomes (multivariable HR, 0.54 [95% CI, .29-.98] and 0.39 [95% CI, .19-.79], respectively).

CONCLUSIONS

Improved virological outcomes among patients infected with non-B subtypes invalidate concerns that these individuals are at a disadvantage because drugs have been designed primarily for subtype B infections.

Non-linear mixed effects modeling of antiretroviral drug response after administration of lopinavir, atazanavir and efavirenz containing regimens to treatment-naïve HIV-1 infected patients

The objective of this analysis was to compare three methods of handling HIV-RNA data below the limit of quantification (LOQ) when describing the time-course of antiretroviral drug response using a drug-disease model. Treatment naïve Scandinavian HIV-positive patients (n = 242) were randomized to one of three study arms. Two nucleoside reverse transcriptase inhibitors were administrated in combination with 400/100 mg lopinavir/ritonavir twice daily, 300/100 mg atazanavir/ritonavir once a day or 600 mg efavirenz once a day. The viral response was monitored at screening, baseline and at 1, 2, 3, 4, 12, 24, 48, 96, 120, and 144 weeks after study initiation. Data up to 400 days was fitted using a viral dynamics non-linear mixed effects drug-disease model in NONMEM. HIV-RNA data below LOQ of 50 copies/ml plasma (39%) was omitted, replaced by LOQ/2 or included in the analysis using a likelihood-based method (M3 method). Including data below LOQ using the M3 method substantially improved the model fit. The drug response parameter expressing the fractional inhibition of viral replication was on average (95% CI) estimated to 0.787 (0.721-0.864) for lopinavir and atazanavir treatment arms and 0.868 (0.796-0.923) for the efavirenz containing regimen. At 400 days after treatment initiation 90% (76-100) of the lopinavir and atazanavir treated patients were predicted to have undetectable viral levels and 96% (89-100%) for the efavirenz containing treatment. Including viral data below the LOQ rather than omitting or replacing data provides advantages such as better model predictions and less biased parameter estimates which are of importance when quantifying antiretroviral drug response.

Perinatal depressive symptoms in HIV-infected versus HIV-uninfected women: a prospective study from preconception to postpartum

OBJECTIVE

Depression is common among HIV-infected women, predicts treatment nonadherence, and consequently may impact vertical transmission of HIV. We report findings from a study evaluating preconception, pregnancy, and postpartum depressive symptoms in HIV-infected vs. at-risk, HIV-uninfected women.

METHODS

We examined the prevalence and predictors of elevated perinatal (i.e., pregnancy and/or postpartum) depressive symptoms using a Center for Epidemiological Studies-Depression (CES-D) scale score of ≥16 in 139 HIV-infected and 105 HIV-uninfected women (62% African American) from the Women's Interagency HIV Study (WIHS).

RESULTS

The prevalence of elevated perinatal depressive symptoms did not differ by HIV serostatus (HIV-infected 44%, HIV-uninfected 50%, p=0.44). Among HIV-infected women, the strongest predictor of elevated symptoms was preconception depression (odds ratio [OR] 5.71, 95% confidence interval [CI] 2.67-12.19, p<0.001); crack, cocaine, and/or heroin use during preconception was marginally significant (OR 3.10, 95% CI 0.96-10.01, p=0.06). In the overall sample, additional significant predictors of perinatal depression included having multiple sex partners preconception (OR 2.20, 95% CI 1.12-4.32, p=0.02), use of preconception mental health services (OR 2.51, 95% CI 1.03-6.13, p=0.04), and not graduating from high school (OR 1.92, 95% CI 1.06-3.46, p=0.03).

CONCLUSIONS

Elevated perinatal depressive symptoms are common among HIV-infected and at-risk HIV-uninfected women. Depressive symptoms before pregnancy were the strongest predictor of perinatal symptoms. Findings underscore the importance of early and ongoing assessment and treatment to ensure low vertical transmission rates and improving postpregnancy outcomes for mothers and children.

The Direct Medical Costs of Late Presentation (<350/mm) of HIV Infection over a 15-Year Period

We describe the immediate- and longer-term direct medical costs of care for individuals diagnosed with HIV at CD4 counts <350/mm(3) ("late presenters"). We collected and stratified by initial CD4 count all inpatient, outpatient, and drug costs for all newly diagnosed patients accessing HIV care within Southern Alberta from 1/1/1995 to 1/1/2010. 59% of new patients were late presenters. We found significantly higher costs for late presenters, especially inpatient costs, during the first year after accessing care. Direct medical costs remained almost twice as high for late presenters in subsequent years compared to patients presenting with CD4 counts >350/mm(3) despite significantly their improved CD4 counts. The sustained high cost for late presenters has implications for recent recommendations for wider routine HIV testing and the earlier initiation of cART. Earlier diagnosis and treatment, while increasing the immediate expenditures within a population, may produce both direct and indirect cost savings in the longer term.

Viral suppression rates in salvage treatment with raltegravir improved with the administration of genotypic partially active or inactive nucleoside/tide reverse transcriptase inhibitors

BACKGROUND

Nucleoside reverse transcriptase inhibitors (NRTIs) are often administered in salvage therapy even if genotypic resistance tests (GRTs) indicate high-level resistance, but little is known about the benefit of these additional NRTIs.

METHODS

The effect of <2 compared with 2 NRTIs on viral suppression (HIV-1 RNA < 50 copies/mL) at week 24 was studied in salvage patients receiving raltegravir. Intent-to-treat and per-protocol analyses were performed; last observation carried forward imputation was used to deal with missing information. Logistic regressions were weighted to create a pseudopopulation in which the probability of receiving <2 and 2 NRTIs was unrelated to baseline factors predicting treatment response.

RESULTS

One-hundred thirty patients were included, of whom 58.5% (n = 76) received <2 NRTIs. NRTIs were often replaced by other drug classes. Patients with 2 NRTIs received less additional drug classes compared with patients with <2 NRTIs [median (IQR): 1 (1-2) compared with 2 (1-2), P Wilcoxon < 0.001]. The activity of non-NRTI treatment components was lower in the 2 NRTIs group compared with the <2 NRTIs group [median (IQR) genotypic sensitivity score: 2 (1.5-2.5) compared with 2.5 (2-3), P Wilcoxon < 0.001]. The administration of <2 NRTIs was associated with a worse viral suppression rate at week 24. The odds ratios were 0.34 (95% confidence interval: 0.13 to 0.89, P = 0.027) and 0.19 (95% confidence interval: 0.05 to 0.79, P = 0.023) when performing the last observation carried forward and the per-protocol approach, respectively.

CONCLUSIONS

Our findings showed that partially active or inactive NRTIs contribute to treatment response, and thus the use of 2 NRTIs in salvage regimens that include raltegravir seems warranted.

Elevated CD8 counts during HAART are associated with HIV virologic treatment failure

OBJECTIVE

To evaluate whether elevated CD8 counts are associated with increased risk of virologic treatment failure in HIV-infected individuals.

DESIGN

Retrospective cohort study.

METHODS

US Military HIV Natural History Study participants who initiated highly active antiretroviral therapy (HAART) in 1996-2008 had 6- and 12-month post-HAART HIV RNA <400 copies per milliliter, ≥ 2 subsequent HIV viral loads and a baseline CD8 count were eligible (n = 817). Baseline was 12 months after the start of HAART, virologic failure (VF) was defined as confirmed HIV RNA ≥ 400 copies per milliliter, and CD8 counts ≥ 1200 cells per cubic millimeter were considered elevated. Cox models were used to examine the effect of baseline and time-updated CD8 counts on VF.

RESULTS

There were 216 failures for a rate of 5.6 per 100 person-years [95% confidence interval (CI): 4.9 to 6.4]. Among those initiating HAART in 2000-2008, the participants with elevated baseline CD8 counts had significantly greater risk of VF compared with those with baseline CD8 counts ≤ 600 cells per cubic millimeter [hazard ratio (HR) = 2.68, 95% CI: 1.13 to 6.35]. The participants with elevated CD8 counts at >20% of previous 6-month follow-up visits had a greater risk of failure at the current visit than those who did not (HR = 1.53, 95% CI: 1.14 to 2.06). Those with CD8 counts that increased after the start of HAART had a greater risk of failure than those with CD8 counts that decreased or remained the same (HR = 1.59, 95% CI: 1.19 to 2.13).

CONCLUSIONS

Initial or serial elevated CD8 counts while on HAART or an increase in CD8 counts from HAART initiation may be early warnings for future treatment failure.

The effect of injecting drug use history on disease progression and death among HIV-positive individuals initiating combination antiretroviral therapy: collaborative cohort analysis

BACKGROUND

We examined whether determinants of disease progression and causes of death differ between injecting drug users (IDUs) and non-IDUs who initiate combination antiretroviral therapy (cART).

METHODS

The ART Cohort Collaboration combines data from participating cohort studies on cART-naïve adults from cART initiation. We used Cox models to estimate hazard ratios for death and AIDS among IDUs and non-IDUs. The cumulative incidence of specific causes of death was calculated and compared using methods that allow for competing risks.

RESULTS

Data on 6269 IDUs and 37 774 non-IDUs were analysed. Compared with non-IDUs, a lower proportion of IDUs initiated cART with a CD4 cell count <200 cells/μL or had a prior diagnosis of AIDS. Mortality rates were higher in IDUs than in non-IDUs (2.08 vs. 1.04 per 100 person-years, respectively; P<0.001). Lower baseline CD4 cell count, higher baseline HIV viral load, clinical AIDS at baseline, and later year of cART initiation were associated with disease progression in both groups. However, the inverse association of baseline CD4 cell count with AIDS and death appeared stronger in non-IDUs than in IDUs. The risk of death from each specific cause was higher in IDUs than non-IDUs, with particularly marked increases in risk for liver-related deaths, and those from violence and non-AIDS infection.

CONCLUSION

While liver-related deaths and deaths from direct effects of substance abuse appear to explain much of the excess mortality in IDUs, they are at increased risk for many other causes of death, which may relate to suboptimal management of HIV disease in these individuals.

Nelfinavir and non-nucleoside reverse transcriptase inhibitor-based salvage regimens in heavily HIV pretreated patients

OBJECTIVE

To assess the efficacy of nelfinavir mesylate (NFV) in combination with delavirdine mesylate (DLV) or efavirenz (EFV) and other antiretroviral agents following virological failure on other protease inhibitor (PI)-based regimens.

DESIGN

Multicentre, retrospective chart review.

METHODS

One hundred-one patients who were naive to both NFV and non-nucleoside reverse transcriptase inhibitors (NNRTIs) and who initiated NFV plus DLV or EFV-based salvage regimens were reviewed. Response to treatment was defined as a reduction in HIV ribonucleic acid (RNA) levels to unquantifiable levels (less than 50 copies/mL, less than 400 copies/mL, less than 500 copies/mL) on at least one occasion after the initiation of salvage therapy. Baseline correlates of response, including prior duration of HIV infection, prior number of regimens, viral load and CD4 cell counts were also evaluated.

RESULTS

Patients had a mean duration of HIV infection of 10 years, a mean duration of prior therapy of four years, a median of four prior nucleoside reverse transcriptase inhibitors and a median of two prior PIs. At the time of review the mean duration of salvage therapy was 63.4 weeks. Virological suppression was achieved in 59 (58.4%) patients within a mean of eight weeks and maintained for a mean of 44.9 weeks (the mean follow-up was 78 weeks). Of the non-responders, 16 (38%) achieved a less than 1 log(10) decrease in HIV RNA levels. Although there was no association between baseline correlates, response rate (75.7%) was significantly higher in patients with HIV RNA levels of 50,000 copies/mL or lower and CD4 counts greater than 200 cells/mm(3).

CONCLUSION

NFV/NNRTI-based highly active antiretroviral therapy regimens are an effective therapy in many patients who have experienced virological breakthroughs on at least one prior PI-based regimen.

Results of antiretroviral treatment interruption and intensification in advanced multi-drug resistant HIV infection from the OPTIMA trial

BACKGROUND

Guidance is needed on best medical management for advanced HIV disease with multidrug resistance (MDR) and limited retreatment options. We assessed two novel antiretroviral (ARV) treatment approaches in this setting.

METHODS AND FINDINGS

We conducted a 2×2 factorial randomized open label controlled trial in patients with a CD4 count≤300 cells/µl who had ARV treatment (ART) failure requiring retreatment, to two options (a) re-treatment with either standard (≤4 ARVs) or intensive (≥5 ARVs) ART and b) either treatment starting immediately or after a 12-week monitored ART interruption. Primary outcome was time to developing a first AIDS-defining event (ADE) or death from any cause. Analysis was by intention to treat. From 2001 to 2006, 368 patients were randomized. At baseline, mean age was 48 years, 2% were women, median CD4 count was 106/µl, mean viral load was 4.74 log(10) copies/ml, and 59% had a prior AIDS diagnosis. Median follow-up was 4.0 years in 1249 person-years of observation. There were no statistically significant differences in the primary composite outcome of ADE or death between re-treatment options of standard versus intensive ART (hazard ratio 1.17; CI 0.86-1.59), or between immediate retreatment initiation versus interruption before re-treatment (hazard ratio 0.93; CI 0.68-1.30), or in the rate of non-HIV associated serious adverse events between re-treatment options.

CONCLUSIONS

We did not observe clinical benefit or harm assessed by the primary outcome in this largest and longest trial exploring both ART interruption and intensification in advanced MDR HIV infection with poor retreatment options.

TRIAL REGISTRATION

Clinicaltrials.gov NCT00050089.

Persistence of HIV-associated cognitive impairment, inflammation, and neuronal injury in era of highly active antiretroviral treatment

OBJECTIVE

To determine whether cognitive impairment and brain injury as measured by proton magnetic resonance spectroscopy (MRS) persist in the setting of HAART.

DESIGN

This study is an observational cohort study.

METHODS

MRS was performed in 268 patients: HIV-negative controls (N = 28), HIV-positive neuroasymptomatic individuals (N = 124), and individuals with AIDS dementia complex (ADC; N = 50) on stable antiretroviral therapy (ART) with a mean duration of infection of 12 years and CD4 cell count of 309 cells/μl. Four metabolites were measured over creatine: N-acetyl aspartate (NAA), marker of neuronal integrity; choline (Cho), myoinositol, markers of inflammation, and glutamate and glutamine (Glx) in the basal ganglia, frontal white matter (FWM), and mid-frontal cortex. Analyses included analysis of variance, analysis of covariance, linear, and nonparametric regression models.

RESULTS

Cognitive impairment was found in 48% of HIV-infected individuals. Both HIV-positive groups showed significant increases in myoinositol/creatine or Cho/creatine in all brain regions when compared to controls; a significant decrease in Glx/creatine in the FWM was observed in the neuroasymptomatic group; and only individuals with ADC showed a significant reduction in NAA/creatine, although a significant trend for decreasing NAA/creatine in the basal ganglia was found across the groups. Effects related to aging and duration of infection, but not central nervous system penetration effectiveness were observed.

CONCLUSION

Brain inflammatory changes remain ubiquitous among HIV-infected individuals, whereas neuronal injury occurs predominantly in those with cognitive impairment. Together these findings indicate that despite the widespread use of HAART, HIV-associated cognitive impairment and brain injury persist in the setting of chronic and stable disease.

Clinical audit: virological and immunological response to combination antiretroviral therapy in HIV patients at a Sydney sexual health clinic

AIM

Bigge Park Centre (BPC) is a sexual health clinic located in a socially disadvantaged area in Southwest Sydney. This served as a retrospective clinical audit, documenting patient demographics, identifying factors associated with virological, immunological and discordant responses, evaluating the centre's ability in HIV control and investigating changes in practice from 1996 to 2007.

METHOD

Data including age, gender, ethnicity, mode of transmission, hepatitis co-infection, prior acquired immune deficiency syndrome (AIDS)-defining-illness, HIV-1 RNA and CD4+cell counts of patients on combination antiretroviral therapy (CART) for treatment of HIV with at least 1-year follow up at the BPC were analysed. Results were compared with other cohorts in medical literature.

RESULTS

BPC manages HIV patients from diverse backgrounds. Sequential monotherapy was associated with poor virological control, lower CD4+cell recovery and discordant response. When patients who had sequential monotherapy were excluded, Caucasian race, high viral load at 1 month and triple-NRTI (nucleoside reverse transcriptase inhibitor) regimen were associated with lack of virological control. Lower baseline viral load and triple-NRTI regimen were associated with lower CD4+cell recovery. Lower baseline CD4+cell count and prior diagnosis of AIDS were associated with discordant response. Virological control and CD4+cell recovery achieved were comparable to that documented in medical literature. There was no significant change over time in terms of timing of CART initiation, attainment of immunological response or virological control since the late 1990 s.

CONCLUSION

HIV control achieved at the BPC was comparable to that reported in medical literature. Enhancement of strategies to promote screening and improve adherence as well as performance of HIV resistance assessment and avoidance of triple-NRTI therapy will likely improve patient care.

Lower CD4 cell count and higher virus load, but not antiretroviral drug resistance, are associated with AIDS-defining events and mortality: an ACTG Longitudinal Linked Randomized Trials (ALLRT) analysis

BACKGROUND

We hypothesized that drug resistance mutations would impact clinical outcomes associated with HIV-1 infection.

METHODS

A matched case-control study of participants in AIDS Clinical Trials Group Longitudinal Linked Randomized Trials (ALLRT). Cases experienced an AIDS-defining event (ADE) or mortality, and controls did not. One hundred thirty-four cases were identified and matched to a total of 266 controls by age, sex, treatment regimen, and length of follow-up. Both cases and controls had HIV RNA levels of ≥ 500 copies/mL within 24 weeks of an event. Population-based genotyping at or near the time of the event was used to evaluate the impact of resistance mutations on incidence of ADE and/or death using conditional logistic regression models.

RESULTS

One hundred four cases and 183 controls were analyzed. Median time to event was 99 weeks; 6 cases were deaths. At baseline, cases had lower CD4 (median 117 vs 235 cells/mm3; P < .0001) and higher HIV RNA levels (median 205,000 vs 57,000 copies/mL; P = .003). No significant differences in resistance were seen between cases and controls.

CONCLUSIONS

In this rigorously designed case-control study, lower CD4 cell counts and higher virus loads, not antiretroviral drug resistance, were strongly associated with ADE and mortality.

Immune reconstitution after a decade of combined antiretroviral therapies for human immunodeficiency virus

The introduction of combined antiretroviral therapies (HAART) has reversed the fatal course of human immunodeficiency virus (HIV) infection. HAART controls virus production and, in most cases, allows the quantitative and functional immune defects caused by HIV to be reversed. Here, we review T cell homeostatic mechanisms that drive immune recovery. These homeostatic mechanisms, as well as differences in T cell antigen exposure, explain the distinct patterns of recovery for HIV-specific T cells versus T cells specific for other pathogens. Immune restoration during HAART can, however, have adverse effects. Immune restoration syndrome occurs in some patients as a result of successful but unbalanced immunity.

Ambiguous nucleotide calls from population-based sequencing of HIV-1 are a marker for viral diversity and the age of infection

The fraction of ambiguous nucleotide calls in bulk sequencing of human immunodeficiency virus type 1 (HIV-1) carries important information on viral diversity and the age of infection. In particular, a fraction of ambiguous nucleotides of >.5% provides evidence against a recent infection event <1 year ago.

Background. The time passed since the infection of a human immunodeficiency virus (HIV)–infected individual (the age of infection) is an important but often only poorly known quantity. We assessed whether the fraction of ambiguous nucleotides obtained from bulk sequencing as done for genotypic resistance testing can serve as a proxy of this parameter.

Methods. We correlated the age of infection and the fraction of ambiguous nucleotides in partial pol sequences of HIV-1 sampled before initiation of antiretroviral therapy (ART). Three groups of Swiss HIV Cohort Study participants were analyzed, for whom the age of infection was estimated on the basis of Bayesian back calculation (n = 3,307), seroconversion (n = 366), or diagnoses of primary HIV infection (n = 130). In addition, we studied 124 patients for whom longitudinal genotypic resistance testing was performed while they were still ART-naïve.

Results. We found that the fraction of ambiguous nucleotides increased with the age of infection with a rate of .2% per year within the first 8 years but thereafter with a decreasing rate. We show that this pattern is consistent with population-genetic models for realistic parameters. Finally, we show that, in this highly representative population, a fraction of ambiguous nucleotides of >.5% provides strong evidence against a recent infection event <1 year prior to sampling (negative predictive value, 98.7%).

Conclusions. These findings show that the fraction of ambiguous nucleotides is a useful marker for the age of infection.

In Vivo validation of a bioinformatics based tool to identify reduced replication capacity in HIV-1

Although antiretroviral drug resistance is common in treated HIV infected individuals, it is not a consistent indicator of HIV morbidity and mortality. To the contrary, HIV resistance-associated mutations may lead to changes in viral fitness that are beneficial to infected individuals. Using a bioinformatics-based model to assess the effects of numerous drug resistance mutations, we determined that the D30N mutation in HIV-1 protease had the largest decrease in replication capacity among known protease resistance mutations. To test this in silico result in an in vivo environment, we constructed several drug-resistant mutant HIV-1 strains and compared their relative fitness utilizing the SCID-hu mouse model. We found HIV-1 containing the D30N mutation had a significant defect in vivo, showing impaired replication kinetics and a decreased ability to deplete CD4+ thymocytes, compared to the wild-type or virus without the D30N mutation. In comparison, virus containing the M184V mutation in reverse transcriptase, which shows decreased replication capacity in vitro, did not have an effect on viral fitness in vivo. Thus, in this study we have verified an in silico bioinformatics result with a biological assessment to identify a unique mutation in HIV-1 that has a significant fitness defect in vivo.

A sequential Cox approach for estimating the causal effect of treatment in the presence of time-dependent confounding applied to data from the Swiss HIV Cohort Study

When estimating the effect of treatment on HIV using data from observational studies, standard methods may produce biased estimates due to the presence of time-dependent confounders. Such confounding can be present when a covariate, affected by past exposure, is both a predictor of the future exposure and the outcome. One example is the CD4 cell count, being a marker for disease progression for HIV patients, but also a marker for treatment initiation and influenced by treatment. Fitting a marginal structural model (MSM) using inverse probability weights is one way to give appropriate adjustment for this type of confounding. In this paper we study a simple and intuitive approach to estimate similar treatment effects, using observational data to mimic several randomized controlled trials. Each 'trial' is constructed based on individuals starting treatment in a certain time interval. An overall effect estimate for all such trials is found using composite likelihood inference. The method offers an alternative to the use of inverse probability of treatment weights, which is unstable in certain situations. The estimated parameter is not identical to the one of an MSM, it is conditioned on covariate values at the start of each mimicked trial. This allows the study of questions that are not that easily addressed fitting an MSM. The analysis can be performed as a stratified weighted Cox analysis on the joint data set of all the constructed trials, where each trial is one stratum. The model is applied to data from the Swiss HIV cohort study.

Long-term efavirenz autoinduction and its effect on plasma exposure in HIV patients

We investigated the influence of gender and pharmacogenetic variations on long-term efavirenz autoinduction and disposition among patients with HIV in Tanzania (N = 129). Plasma concentrations (at 16 h) of efavirenz and 8-hydroxyefavirenz were quantified at weeks 4 and 16 of therapy. Genotyping was performed to identify cytochrome P450 (CYP) 2B6*6, CYP3A5*3, *6, and *7, and ABCB1-3435 C/T genotypes. There were reductions in the median efavirenz concentration (Wilcoxon matched-pair test P < 0.001) and efavirenz/8-hydroxyefavirenz ratio (P < 0.001) by 19 and 32%, respectively, at week 16 as compared with week 4. The proportion of patients with efavirenz concentration <1 µg/ml at week 16 was higher by 67, 25, and 5% in CYP2B6*1/*1, *1/*6, and *6/*6 genotypes, respectively. The defined therapeutic range based on observed plasma concentrations is affected by the time point of sampling and the CYP2B6 genotype. The effect of efavirenz autoinduction on reducing plasma exposure continues up to week 16 and predominantly affects CYP2B6 extensive metabolizers. Among CYP2B6 slow metabolizers, the presence of a CYP3A5 genotype allele is associated with greater effects of efavirenz autoinduction on plasma concentrations of the drug. The cumulative induction may influence the long-term antiretroviral therapy outcome, particularly in CYP2B6*1 carriers.

Retrospective study on the critical factors for retaining patients on antiretroviral therapy in KwaZulu-Natal, South Africa

OBJECTIVE

To analyze the critical factors favoring the retention of patients under antiretroviral therapy (ART) in KwaZulu-Natal (KZN), South Africa.

DESIGN AND METHODS

This retrospective study was based on the review of a representative sample of patients who began ART between March 2004 and May 2006 in 32 public sector sites and were followed up to July 1, 2007. Extended Cox proportional hazard models were used to identify the factors which significantly influenced treatment retention during the first 2 years of treatment. Kaplan-Meyer provided the probabilities of remaining on ART if these factors were present.

RESULTS

The 2835 sampled patients corresponded to about 10% of the universe of patients under ART in the 32 sites; 929 (33%) were males, and the median age of the sampled patients was 34 (interquartile range: 28-41). The analysis identified factors that significantly decreased the probability of remaining on ART. Patients' risk factors were initial CD4 <100 cells per microliter, lack of a telephone contact number, and being male. Sites' risk factors were the presence of a part time (PT) versus a full time (FT) senior professional nurse, a PT versus FT doctor, and intakes of 200 or more new patients per doctor per year. The probability of remaining on ART declined significantly for each increasing level of workload, but having a FT versus a PT doctor made a significant difference only for level of workload of 200 or more new patients per year.

CONCLUSIONS

The analysis has identified the conditions influencing retention of ART patients in KZN. This has provided a method to estimate absorption capacity of the ART delivery sites, which is of added value for a sustainable expansion of the ART coverage.

Incidence of modifying or discontinuing first HAART regimen and its determinants in a cohort of HIV-infected patients from Rio de Janeiro, Brazil

Studies on the long-term safety and tolerability of HAART are scarce in developing countries. HAART has been universally available in Brazil since 1997, providing a unique opportunity to evaluate the incidence and risk factors for HAART discontinuation or modification. We analyzed retrospective data from 670 treatment-naive patients followed at the HIV cohort of Evandro Chagas Clinical Research Institute, Oswaldo Cruz Foundation, in Rio de Janeiro, Brazil, who first received HAART between January 1996 and December 2006. Our four outcomes of interest were treatment failure (TF-MOD), short-term toxicity (ST-MOD), long-term toxicity (LT-MOD), and overall modification/discontinuation (MOD, composed of TF-MOD, ST-MOD, LT-MOD, and other reasons). Risk factors were assessed using Cox's proportional hazards regression. Incidences of MOD, ST-MOD, LT-MOD, and TF-MOD were 28.3, 24.0, 4.0, and 5.6 per 100 persons-years, respectively. MOD was observed in 69% of the patients; 40% of the MODs were toxicity related. The risk of MOD in the first year of treatment was 32% (95% CI: 28.3-35.5%); the median time from HAART initiation to MOD was 14 months (IQR: 3.0-29.5). The most frequent reasons for ST-MOD were gastrointestinal; women had a higher hazard for ST-MOD. Metabolic toxicity was the most frequent reason for LT- MOD, particularly dislipidemia and lipodystrophy. Increased hazard of TF-MOD was observed among those with lower CD4(+) lymphocyte counts (<200 cells/mm(3)). Our results indicate that toxicities can compromise adherence and thus impact future treatment options. This is especially relevant in the context of limited access to second and third line treatment regimens.

Trends over calendar time in antiretroviral treatment success and failure in HIV clinic populations

OBJECTIVE

Effective antiretroviral therapy (ART) has transformed the care of people with HIV, but it is important to monitor time trends in indicators of treatment success and antic future changes.

METHODS

We assessed time trends from 2000 to 2007 in several indicators of treatment success in the UK Collaborative HIV Cohort (CHIC) Study, and using national HIV data from the Health Protection Agency (HPA) we developed a model to project future trends.

RESULTS

The proportion of patients on ART with a viral load <50 HIV-1 RNA copies/mL increased from 62% in 2000 to 84% in 2007, and the proportion of all patients with a CD4 count <200 cells/microL decreased from 21% to 10%. During this period, the number of patients who experienced extensive triple class failure (ETCF) rose from 147 (0.9%) to 1771 (3.9%). The number who experienced such ETCF and had a current viral load >50 copies/mL rose fromz 118 (0.7%) to 857 (1.9%). Projections to 2012 suggest sustained high levels of success, with a continued increase in the number of patients who have failed multiple drugs but a relatively stable number of such patients experiencing viral loads >50 copies/mL. Numbers of deaths are projected to remain low.

CONCLUSIONS

There have been continued improvements in key indicators of success in patients with HIV from 2000 to 2007. Although the number of patients who have ETCF is projected to rise in the future, the number of such patients with viral loads >50 copies/mL is not projected to increase up to 2012. New drugs may be needed in future to sustain these positive trends.

Clinical evaluation of a dried blood spot assay for atazanavir

Current procedures for obtaining and measuring plasma concentrations of HIV protease inhibitors (PIs) are technically challenging. Dried blood spot (DBS) assays offer a way to overcome many of the obstacles. We sought to develop a DBS assay for quantitation of the PI atazanavir (ATV) and to compare this method with a previously validated plasma assay. We prospectively enrolled 48 patients with well-controlled HIV disease who had been on ATV for at least 7 days. ATV was quantified from plasma by use of high-performance liquid chromatography (HPLC). A reversed-phase ultrahigh-performance liquid chromatography (UPLC) assay was utilized for DBS samples. The concentrations of ATV quantified in a DBS matrix showed very strong agreement with those measured in plasma (r(2) = 0.988). The mean difference in ATV concentration between the two methods was -10.8% (95% confidence interval [95% CI], -7.65% to -13.95%), indicating that the DBS method has a slight negative bias. A majority (97.8%) of the differences in concentration between the two assays fell within ±2 standard deviations. ATV concentrations were lower in subjects who had detectable HIV RNA in plasma (mean, 543 ng/ml) than in those with HIV RNA of <50 copies/ml (mean, 1,582 ng/ml) (P = 0.03, Wilcoxon rank-sum test). In conclusion, our study demonstrated that ATV quantitation in a DBS matrix is feasible and accurate. DBS use offers a convenient alternative for measuring plasma concentrations of ATV and may have utility in monitoring of drug concentrations in clinical practice and in future studies.

Incidence and determinants of new AIDS-defining illnesses after HAART initiation in a Senegalese cohort

BACKGROUND

Although a dramatic decrease in AIDS progression has been observed after Highly Active Anti Retroviral Therapy (HAART) in both low- and high-resource settings, few data support that fact in low-resource settings.This study describes the incidence of AIDS-defining illnesses (ADI) after HAART initiation and analyzes their risk factors in a low-resource setting. A focus was put on CD4 cell counts and viral load measurements.

METHODS

404 HIV-1-infected Senegalese adult patients were enrolled in a prospective observational cohort and data censored as of April 2008. A Poisson regression was used to model the incidence of ADIs over two periods and to assess its association with baseline variables, current CD4, current viral load, CD4 response, and virological response.

RESULTS

ADI incidence declined from 20.5 ADIs per 100 person-years, 95% CI = [16.3;25.8] during the first year to 4.3, 95% CI = [2.3;8.1] during the fourth year but increased afterwards. Before 42 months, the decrease was greater in patients with clinical stage CDC-C at baseline and with a viral load remaining below 1000 cp/mL but was uniform across CD4 strata (p = 0.1). After 42 months, 293 patients were still at risk. The current CD4 and viral load were associated with ADI incidence (decrease of 21% per 50 CD4/mm3 and of 61% for patients with a viral load < 1000 cp/mL).

CONCLUSIONS

During the first four years, a uniform decline of ADI incidence was observed even in patients with low CD4-cell counts at HAART initiation as long as the viral load remained undetectable. An increase was noted later in patients with immunologic and virological failures but also in patients with only virological failure.

[AIDS Study Group/Spanish AIDS Plan consensus document on antiretroviral therapy in adults with human immunodeficiency virus infection (updated January 2010)]

OBJECTIVE

This consensus document is an update of antiretroviral therapy recommendations for adult patients with human immunodeficiency virus infection.

METHODS

To formulate these recommendations a panel made up of members of the Grupo de Estudio de Sida (Gesida, AIDS Study Group) and the Plan Nacional sobre el Sida (PNS, Spanish AIDS Plan) reviewed the advances in the current understanding of the pathophysiology of human immunodeficiency virus (HIV) infection, the efficacy and safety of clinical trials, and cohort and pharmacokinetic studies published in biomedical journals or presented at scientific meetings. Three levels of evidence were defined according to the data source: randomized studies (level A), cohort or case-control studies (level B), and expert opinion (level C). The decision to recommend, consider or not to recommend ART was established in each situation.

RESULTS

Currently, the treatment of choice for chronic HIV infection is the combination of three drugs of two different classes, including 2 nucleosides or nucleotide analogs (NRTI) plus 1 non-nucleoside (NNRTI) or 1 boosted protease inhibitor (PI/r), but other combinations are possible. Initiation of ART is recommended in patients with symptomatic HIV infection. In asymptomatic patients, initiation of ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts below 350 cells/microl; 2) When CD4 counts are between 350 and 500 cells/microl, therapy should be started in case of cirrhosis, chronic hepatitis C, high cardiovascular risk, HIV nephropathy, HIV viral load above 100,000 copies/ml, proportion of CD4 cells under 14%, and in people aged over 55; 3) Therapy should be deferred when CD4 are above 500 cells/microl, but could be considered if any of previous considerations concurs. Treatment should be initiated in case of hepatitis B requiring treatment and should be considered for reduce sexual transmission. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures but undetectable viral loads maybe possible with the new drugs even in highly drug experienced patients. Genotype studies are useful in these situations. Drug toxicity of ART therapy is losing importance as benefits exceed adverse effects. Criteria for antiretroviral treatment in acute infection, pregnancy and post-exposure prophylaxis are mentioned as well as the management of HIV co-infection with hepatitis B or C.

CONCLUSIONS

CD4 cells counts, viral load and patient co-morbidities are the most important reference factors to consider when initiating ART in asymptomatic patients. The large number of available drugs, the increased sensitivity of tests to monitor viral load, and the ability to determine viral resistance is leading to a more individualized therapy approach in order to achieve undetectable viral load under any circumstances.

HIV-1 transmission after cessation of early antiretroviral therapy among men having sex with men

OBJECTIVE

To study transmission dynamics during acute infection, during the aviremic phase over the period of early antiretroviral therapy (ART) and during the phase of viral rebound after early treatment was stopped.

METHODS

Transmission dynamics was assessed within 111 patients, enrolled in the Zurich primary HIV infection study, by molecular epidemiological methods using pol sequences from genotypic resistance tests and clonal env C2-V3-C3 sequences. Coclustering of Zurich primary HIV infection sequences with 12,303 sequences from 8837 HIV-positive patients enrolled in the multisite Swiss HIV Cohort Study was identified. Furthermore, we investigated transmission patterns within phylogenetic clusters by using longitudinal clinical data and analyzed HIV transmission by stage of infection and attempted to localize transmission events to periods before or after early ART.

RESULTS

Six transmission clusters comprising 20 men having sex with men were identified. Furthermore, linkage to eight men having sex with men from the Swiss HIV Cohort Study could be established. Strikingly, we detected at least five new primary infection events originating from Zurich primary HIV infection patients within 16-61 weeks after stopping early ART. Viral loads of likely index patients varied from 314 up to 1,690,000 HIV-1 RNA copies/ml of plasma at the estimated time of infection.

CONCLUSION

The large number of new infections originating from men having sex with men who stopped early ART indicates that current preventive efforts are insufficient. In contrast, these patients showed no adherence problems. These findings argue for early, continuous ART in sexually active HIV-1-infected persons not only for individual patient benefits but also specifically to reduce the spread of HIV-1.

Evolution and recombination of genes encoding HIV-1 drug resistance and tropism during antiretroviral therapy

Characterization of residual plasma virus during antiretroviral therapy (ART) is a high priority to improve understanding of HIV-1 pathogenesis and therapy. To understand the evolution of HIV-1 pol and env genes in viremic patients under selective pressure of ART, we performed longitudinal analyses of plasma-derived pol and env sequences from single HIV-1 genomes. We tested the hypotheses that drug resistance in pol was unrelated to changes in coreceptor usage (tropism), and that recombination played a role in evolution of viral strains. Recombinants were identified by using Bayesian and other computational methods. High-level genotypic resistance was seen in approximately 70% of X4 and R5 strains during ART. There was no significant association between resistance and tropism. Each patient displayed at least one recombinant encompassing env and representing a change in predicted tropism. These data suggest that, in addition to mutation, recombination can play a significant role in shaping HIV-1 evolution.

Genetic variation in IL28B is associated with chronic hepatitis C and treatment failure: a genome-wide association study

BACKGROUND & AIMS

Hepatitis C virus (HCV) induces chronic infection in 50% to 80% of infected persons; approximately 50% of these do not respond to therapy. We performed a genome-wide association study to screen for host genetic determinants of HCV persistence and response to therapy.

METHODS

The analysis included 1362 individuals: 1015 with chronic hepatitis C and 347 who spontaneously cleared the virus (448 were coinfected with human immunodeficiency virus [HIV]). Responses to pegylated interferon alfa and ribavirin were assessed in 465 individuals. Associations between more than 500,000 single nucleotide polymorphisms (SNPs) and outcomes were assessed by multivariate logistic regression.

RESULTS

Chronic hepatitis C was associated with SNPs in the IL28B locus, which encodes the antiviral cytokine interferon lambda. The rs8099917 minor allele was associated with progression to chronic HCV infection (odds ratio [OR], 2.31; 95% confidence interval [CI], 1.74-3.06; P = 6.07 x 10(-9)). The association was observed in HCV mono-infected (OR, 2.49; 95% CI, 1.64-3.79; P = 1.96 x 10(-5)) and HCV/HIV coinfected individuals (OR, 2.16; 95% CI, 1.47-3.18; P = 8.24 x 10(-5)). rs8099917 was also associated with failure to respond to therapy (OR, 5.19; 95% CI, 2.90-9.30; P = 3.11 x 10(-8)), with the strongest effects in patients with HCV genotype 1 or 4. This risk allele was identified in 24% of individuals with spontaneous HCV clearance, 32% of chronically infected patients who responded to therapy, and 58% who did not respond (P = 3.2 x 10(-10)). Resequencing of IL28B identified distinct haplotypes that were associated with the clinical phenotype.

CONCLUSIONS

The association of the IL28B locus with natural and treatment-associated control of HCV indicates the importance of innate immunity and interferon lambda in the pathogenesis of HCV infection.

Implementation of raltegravir in routine clinical practice: selection criteria for choosing this drug, virologic response rates, and characteristics of failures

BACKGROUND

Raltegravir (RAL) achieved remarkable virologic suppression rates in randomized-clinical trials, but today efficacy data and factors for treatment failures in a routine clinical care setting are limited.

METHODS

First, factors associated with a switch to RAL were identified with a logistic regression including patients from the Swiss HIV Cohort Study with a history of 3 class failure (n = 423). Second, predictors for virologic outcome were identified in an intent-to-treat analysis including all patients who received RAL. Last observation carried forward imputation was used to determine week 24 response rate (HIV-1 RNA >or= 50 copies/mL).

RESULTS

The predominant factor associated with a switch to RAL in patients with suppressed baseline RNA was a regimen containing enfuvirtide [odds ratio 41.9 (95% confidence interval: 11.6-151.6)]. Efficacy analysis showed an overall response rate of 80.9% (152/188), whereas 71.8% (84/117) and 95.8% (68/71) showed viral suppression when stratified for detectable and undetectable RNA at baseline, respectively. Overall CD4 cell counts increased significantly by 42 cells/microL (P < 0.001). Characteristics of failures were a genotypic sensitivity score of the background regimen <or=1, very low RAL plasma concentrations, poor adherence, and high viral load at baseline.

CONCLUSIONS

Virologic suppression rates in our routine clinical care setting were promising and comparable with data from previously published randomized-controlled trials.

Epidemiology of treatment failure: a focus on recent trends

PURPOSE OF REVIEW

As antiretroviral therapy has been refined with the development of more potent agents and simpler regimens, fewer individuals experience treatment failure. This review will highlight recent trends in treatment failure and virologic resistance in the developed world and resource-limited settings.

RECENT FINDINGS

The goal of antiretroviral therapy in all individuals, regardless of prior treatment exposure or HIV drug resistance, is to achieve full suppression of viral replication with a viral load of less than 50 copies/ml. This goal has been made a reality by the development of newer agents and simpler, better tolerated regimens. Recent cohort studies have demonstrated improved virologic outcomes in the current antiretroviral era, with decreased rates of virologic failure and associated resistance. Improved tolerability has aided adherence, which remains a key determinant of treatment success. Cohorts in resource-limited settings report improved clinical and virologic outcomes as rollout of highly active antiretroviral therapy programs continues.

SUMMARY

There has been a reassuring decrease in the frequency of virological failure and drug resistance in the modern highly active antiretroviral therapy era. This observation provides an important incentive to strengthen support of antiretroviral therapy programs to optimize virological outcomes, particularly in resource-limited settings in which access to newer agents and laboratory monitoring may be needed to ensure sustainable success.

Provider-focused intervention increases adherence-related dialogue but does not improve antiretroviral therapy adherence in persons with HIV

BACKGROUND

Physicians' limited knowledge of patients' antiretroviral adherence may reduce their ability to perform effective adherence counseling.

METHODS

We conducted a randomized, cross-over study of an intervention to improve physicians' knowledge of patients' antiretroviral adherence. The intervention was a report given to the physician before a routine office visit that included data on Medication Event Monitoring System and self-reported data on antiretroviral adherence, patients' beliefs about antiretroviral therapy, reasons for missed doses, alcohol and drug use, and depression. We audio recorded 1 intervention and 1 control visit for each patient to analyze differences in adherence-related dialogue.

RESULTS

One hundred fifty-six patients were randomized, and 106 completed all 5 study visits. Paired audio recorded visits were available for 58 patients. Using a linear regression model that adjusted for site and baseline Medication Event Monitoring System adherence, adherence after intervention visits did not differ significantly from control visits (2.0% higher, P = 0.31, 95% confidence interval: -1.95% to 5.9%). There was a trend toward more total adherence-related utterances (median of 76 vs. 49.5, P = 0.07) and a significant increase in utterances about the current regimen (median of 51.5 vs. 32.5, P = 0.0002) in intervention compared with control visits. However, less than 10% of adherence-related utterances were classified as "problem solving" in content, and one third of physicians' problem-solving utterances were directive in nature.

CONCLUSIONS

Receipt of a detailed report before clinic visits containing data about adherence and other factors did not improve patients' antiretroviral adherence. Analyses of patient-provider dialogue suggests that providers who care for persons with HIV may benefit from training in adherence counseling techniques.

Magnitude and determinants of nonadherence and nonreadiness to highly active antiretroviral therapy among people living with HIV/AIDS in Northwest Ethiopia: a cross-sectional study

Background

Adequate antiretroviral drug potency is essential for obtaining therapeutic benefit, however, the behavioral aspects of proper adherence and readiness to medication, often determine therapeutic outcome. Therefore, this study aimed to assess the level and determinants of nonadherence and nonreadiness to highly active antiretroviral therapy (HAART) among people living with HIV/AIDS (PLWHA) at Gondar University Teaching Hospital and Felege Hiwot Hospital in Northwest Ethiopia.

Methods

A cross-sectional study was conducted between July and September 2008 using structured interviewer-administered questionnaire. All consecutive adult outpatients who were receiving antiretroviral treatment for at least three months, seen at both hospitals during the study period and able to give informed consent were included in the study. Multivariate logistic regression was used to determine factors associated with nonadherence and nonreadiness.

Results

A total of 504 study subjects were included in this study. The prevalence rates of nonadherence and nonreadiness to HAART were 87 (17.3%) and 70 (13.9%) respectively. Multivariate logistic regression analysis revealed that medication adverse effects, nonreadiness to HAART, contact with psychiatric care service and having no goal had statistically significant association with nonadherence. Moreover, unwillingness to disclose HIV status was significantly associated with nonreadiness to HAART.

Conclusions

In this study the level of nonadherence and nonreadiness to HAART seems to be encouraging. Several factors associated with nonadherance and nonreadiness to HAART were identified. Efforts to minimize nonadherence and nonreadiness to HAART should be integrated in to regular clinical follow up of patients.

The effect of combined antiretroviral therapy on the overall mortality of HIV-infected individuals

OBJECTIVE

To estimate the effect of combined antiretroviral therapy (cART) on mortality among HIV-infected individuals after appropriate adjustment for time-varying confounding by indication.

DESIGN

A collaboration of 12 prospective cohort studies from Europe and the United States (the HIV-CAUSAL Collaboration) that includes 62 760 HIV-infected, therapy-naive individuals followed for an average of 3.3 years. Inverse probability weighting of marginal structural models was used to adjust for measured confounding by indication.

RESULTS

Two thousand and thirty-nine individuals died during the follow-up. The mortality hazard ratio was 0.48 (95% confidence interval 0.41-0.57) for cART initiation versus no initiation. In analyses stratified by CD4 cell count at baseline, the corresponding hazard ratios were 0.29 (0.22-0.37) for less than 100 cells/microl, 0.33 (0.25-0.44) for 100 to less than 200 cells/microl, 0.38 (0.28-0.52) for 200 to less than 350 cells/microl, 0.55 (0.41-0.74) for 350 to less than 500 cells/microl, and 0.77 (0.58-1.01) for 500 cells/microl or more. The estimated hazard ratio varied with years since initiation of cART from 0.57 (0.49-0.67) for less than 1 year since initiation to 0.21 (0.14-0.31) for 5 years or more (P value for trend <0.001).

CONCLUSION

We estimated that cART halved the average mortality rate in HIV-infected individuals. The mortality reduction was greater in those with worse prognosis at the start of follow-up.

Early severe morbidity and resource utilization in South African adults on antiretroviral therapy

Background

High rates of mortality and morbidity have been described in sub-Saharan African patients within the first few months of starting highly active antiretroviral therapy (HAART). There is limited data on the causes of early morbidity on HAART and the associated resource utilization.

Methods

A cross-sectional study was conducted of medical admissions at a secondary-level hospital in Cape Town, South Africa. Patients on HAART were identified from a register and HIV-infected patients not on HAART were matched by gender, month of admission, and age group to correspond with the first admission of each case. Primary reasons for admission were determined by chart review. Direct health care costs were determined from the provider's perspective.

Results

There were 53 in the HAART group with 70 admissions and 53 in the no-HAART group with 60 admissions. The median duration of HAART was 1 month (interquartile range 1-3 months). Median baseline CD4 count in the HAART group was 57 × 10⁶ cells/L (IQR 15-115). The primary reasons for admission in the HAART group were more likely to be due to adverse drug reactions and less likely to be due to AIDS events than the no-HAART group (34% versus 7%; p < 0.001 and 39% versus 63%; p = 0.005 respectively). Immune reconstitution inflammatory syndrome was the primary reason for admission in 10% of the HAART group. Lengths of hospital stay per admission and inpatient survival were not significantly different between the two groups. Five of the 15 deaths in the HAART group were due to IRIS or adverse drug reactions. Median costs per admission of diagnostic and therapeutic services (laboratory investigations, radiology, intravenous fluids and blood, and non-ART medications) were higher in the HAART group compared with the no-HAART group (US$190 versus US$111; p = 0.001), but the more expensive non-curative costs (overhead, capital, and clinical staff) were not significantly different (US$1199 versus US$1128; p = 0.525).

Conclusions

Causes of early morbidity are different and more complex in HIV-infected patients on HAART. This results in greater resource utilization of diagnostic and therapeutic services.

Impact of previous virological treatment failures and adherence on the outcome of antiretroviral therapy in 2007

Background

Combination antiretroviral treatment (cART) has been very successful, especially among selected patients in clinical trials. The aim of this study was to describe outcomes of cART on the population level in a large national cohort.

Methods

Characteristics of participants of the Swiss HIV Cohort Study on stable cART at two semiannual visits in 2007 were analyzed with respect to era of treatment initiation, number of previous virologically failed regimens and self reported adherence. Starting ART in the mono/dual era before HIV-1 RNA assays became available was counted as one failed regimen. Logistic regression was used to identify risk factors for virological failure between the two consecutive visits.

Results

Of 4541 patients 31.2% and 68.8% had initiated therapy in the mono/dual and cART era, respectively, and been on treatment for a median of 11.7 vs. 5.7 years. At visit 1 in 2007, the mean number of previous failed regimens was 3.2 vs. 0.5 and the viral load was undetectable (<50 copies/ml) in 84.6% vs. 89.1% of the participants, respectively. Adjusted odds ratios of a detectable viral load at visit 2 for participants from the mono/dual era with a history of 2 and 3, 4, >4 previous failures compared to 1 were 0.9 (95% CI 0.4–1.7), 0.8 (0.4–1.6), 1.6 (0.8–3.2), 3.3 (1.7–6.6) respectively, and 2.3 (1.1–4.8) for >2 missed cART doses during the last month, compared to perfect adherence. From the cART era, odds ratios with a history of 1, 2 and >2 previous failures compared to none were 1.8 (95% CI 1.3–2.5), 2.8 (1.7–4.5) and 7.8 (4.5–13.5), respectively, and 2.8 (1.6–4.8) for >2 missed cART doses during the last month, compared to perfect adherence.

Conclusions

A higher number of previous virologically failed regimens, and imperfect adherence to therapy were independent predictors of imminent virological failure.

Prognosis of patients treated with cART from 36 months after initiation, according to current and previous CD4 cell count and plasma HIV-1 RNA measurements

OBJECTIVES

CD4 cell count and plasma viral load are well known predictors of AIDS and mortality in HIV-1-infected patients treated with combination antiretroviral therapy (cART). This study investigated, in patients treated for at least 3 years, the respective prognostic importance of values measured at cART initiation, and 6 and 36 months later, for AIDS and death.

METHODS

Patients from 15 HIV cohorts included in the ART Cohort Collaboration, aged at least 16 years, antiretroviral-naive when they started cART and followed for at least 36 months after start of cART were eligible.

RESULTS

Among 14 208 patients, the median CD4 cell counts at 0, 6 and 36 months were 210, 320 and 450 cells/microl, respectively, and 78% of patients achieved viral load less than 500 copies/ml at 6 months. In models adjusted for characteristics at cART initiation and for values at all time points, values at 36 months were the strongest predictors of subsequent rates of AIDS and death. Although CD4 cell count and viral load at cART initiation were no longer prognostic of AIDS or of death after 36 months, viral load at 6 months and change in CD4 cell count from 6 to 36 months were prognostic for rates of AIDS from 36 months.

CONCLUSIONS

Although current values of CD4 cell count and HIV-1 RNA are the most important prognostic factors for subsequent AIDS and death rates in HIV-1-infected patients treated with cART, changes in CD4 cell count from 6 to 36 months and the value of 6-month HIV-1 RNA are also prognostic for AIDS.

Collaboration of Observational HIV Epidemiological Research Europe (COHERE) study group, Bohlius J, Schmidlin K, Costagliola D, Fätkenheuer G, May M, Caro Murillo AM, Mocroft A, Bonnet F, Clifford G, Touloumi G, Miro JM, Chene G, Lundgren J, Egger M. Prognosis of HIV-associated non-Hodgkin lymphoma in patients starting combination antiretroviral therapy

OBJECTIVE

We examined survival and prognostic factors of patients who developed HIV-associated non-Hodgkin lymphoma (NHL) in the era of combination antiretroviral therapy (cART).

DESIGN AND SETTING

Multicohort collaboration of 33 European cohorts.

METHODS

We included all cART-naive patients enrolled in cohorts participating in the Collaboration of Observational HIV Epidemiological Research Europe (COHERE) who were aged 16 years or older, started cART at some point after 1 January 1998 and developed NHL after 1 January 1998. Patients had to have a CD4 cell count after 1 January 1998 and one at diagnosis of the NHL. Survival and prognostic factors were estimated using Weibull models, with random effects accounting for heterogeneity between cohorts.

RESULTS

Of 67 659 patients who were followed up during 304 940 person-years, 1176 patients were diagnosed with NHL. Eight hundred and forty-seven patients (72%) from 22 cohorts met inclusion criteria. Survival at 1 year was 66% [95% confidence interval (CI) 63-70%] for systemic NHL (n = 763) and 54% (95% CI: 43-65%) for primary brain lymphoma (n = 84). Risk factors for death included low nadir CD4 cell counts and a history of injection drug use. Patients developing NHL on cART had an increased risk of death compared with patients who were cART naive at diagnosis.

CONCLUSION

In the era of cART two-thirds of patients diagnosed with HIV-related systemic NHL survive for longer than 1 year after diagnosis. Survival is poorer in patients diagnosed with primary brain lymphoma. More advanced immunodeficiency is the dominant prognostic factor for mortality in patients with HIV-related NHL.

Risk factors for treatment-limiting toxicities in patients starting nevirapine-containing antiretroviral therapy

BACKGROUND

This collaboration of seven observational clinical cohorts investigated risk factors for treatment-limiting toxicities in both antiretroviral-naive and experienced patients starting nevirapine-based combination antiretroviral therapy (NVPc).

METHODS

Patients starting NVPc after 1 January 1998 were included. CD4 cell count at starting NVPc was classified as high (>400/microl/>250/microl for men/women, respectively) or low. Cox models were used to investigate risk factors for discontinuations due to hypersensitivity reactions (HSR, n = 6547) and discontinuation of NVPc due to treatment-limiting toxicities and/or patient/physician choice (TOXPC, n = 10,186). Patients were classified according to prior antiretroviral treatment experience and CD4 cell count/viral load at start NVPc. Models were stratified by cohort and adjusted for age, sex, nadir CD4 cell count, calendar year of starting NVPc and mode of transmission.

RESULTS

Median time from starting NVPc to TOXPC and HSR were 162 days [interquartile range (IQR) 31-737] and 30 days (IQR 17-60), respectively. In adjusted Cox analyses, compared to naive patients with a low CD4 cell count, treatment-experienced patients with high CD4 cell count and viral load more than 400 had a significantly increased risk for HSR [hazard ratio 1.45, confidence interval (CI) 1.03-2.03] and TOXPC within 18 weeks (hazard ratio 1.34, CI 1.08-1.67). In contrast, treatment-experienced patients with high CD4 cell count and viral load less than 400 had no increased risk for HSR 1.10 (0.82-1.46) or TOXPC within 18 weeks (hazard ratio 0.94, CI 0.78-1.13).

CONCLUSION

Our results suggest it may be relatively well tolerated to initiate NVPc in antiretroviral-experienced patients with high CD4 cell counts provided there is no detectable viremia.

Criteria for initiating highly active antiretroviral therapy and short-term immune response among HIV-1-infected patients in Côte d'Ivoire

OBJECTIVES

The aims of this study were to determine the predictors of CD4 count below 200 cells/microL and to propose an algorithm for antiretroviral therapy initiation; and to assess the determinants of immune response to highly active antiretroviral therapy (HAART) in Côte d'Ivoire.

METHODS

A total of 615 consecutive patients attending an HIV/AIDS day hospital were enrolled in the study. We constructed a score system based on the results of a multivariate logistic regression analysis of the predictors of CD4 count <200 cells/microL with the intention of proposing an algorithm able to accurately designate patients eligible for HAART. We also identified factors associated with a short-term increase in CD4 count >50 cells/microL after HAART initiation.

RESULTS

Total lymphocyte count <1200 cells/microL (P<0.0001), lower haemoglobin levels (P<0.0001), and Centers for Disease Control and Prevention (CDC) clinical stages C (P=0.005) and B (P=0.045), as compared with stage A, were associated with CD4 count <200 cells/microL. Nonetheless, no accurate algorithm for HAART initiation was found. Three hundred and three of the 615 patients were treated. Of these 303 patients, 79.5% showed an increase of >50 cells/microL in CD4 count 6 months after HAART initiation (median increase 128 cells/microL). Adherence >or=95% (P=0.022) and increase in absolute total lymphocyte count during follow-up (P<0.0001) were associated with a short-term positive immune response.

CONCLUSIONS

Our results support the effectiveness of generic drug combinations in sub-Saharan Africa. In order to enhance the management of HIV disease in sub-Saharan Africa, efforts should target the development of low-cost CD4 cell count laboratory tests.

Improvements in antiretroviral therapy outcomes over calendar time

PURPOSE OF REVIEW

The introduction of combination antiretroviral therapy (cART) led to substantial reductions in HIV-associated morbidity and mortality. However, the regimens in the early cART era were cumbersome and toxic. The introduction of new ART agents, fixed-dose combinations and novel strategies for cART delivery such as ritonavir 'boosting' of HIV-protease inhibitors have led to a perception of improvements in the tolerability and durability of contemporary cART regimens. It is in turn assumed that these developments have led to improved outcomes in the latter era of cART.

RECENT FINDINGS

Both cohort studies and randomized clinical trials suggest improvements in cART outcomes over calendar time. Key associated factors include reduced pill burden and dosing interval and improved tolerability and reduced toxicity of newer ART. A critical appreciation of the association between ART adherence and regimen durability has been important. Cohorts in recent times have included more patients who are completely ART-naïve at therapy initiation.

SUMMARY

The prognosis of HIV infection in developed countries is in the order of 40 years after cART initiation. An appreciation of the factors associated with long-term control of HIV viraemia is essential for the optimal management of the HIV-infected individual in contemporary practice.

A combination drug of abacavir-lamivudine-zidovudine (Trizivir) for treating HIV infection and AIDS

BACKGROUND

The human immunodeficiency virus (HIV) has become one of the greatest challenges to global public health. In 2007 UNAIDS estimated that 33.2 million people were living with HIV. Currently recommended regimens for initiating HIV treatment consist of either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or ritonvair-boosted protease inhibitor (PI) combined with two nucleoside reverse transcriptase inhibitors (NRTIs); however, there may be some patients for whom NNRTIs and PIs may not be appropriate.

OBJECTIVES

The aim of this review was to evaluate the effects of Trizivir, a fixed-dose combination of three NRTIs (abacavir-lamivudine-zidovudine) for initial treatment of HIV infection.

SEARCH STRATEGY

In February 2008, we searched the Cochrane Library, PubMed, EMBASE, AIDSearch and GATEWAY and checked reference lists of identified articles. In May 2009, we repeated the search in PubMed and the Cochrane Library.

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) with a minimum follow-up time of six months which compared Trizivir with either a PI- or NNRTI-based therapy among antiretroviral-naive HIV-infected patients aged at least 13 years.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data. We calculated the relative risk (RR) or mean difference (as appropriate) for each outcome with its 95% confidence interval (CI) and conducted meta-analysis using the random-effects method because of significant statistical heterogeneity (P<0.1).

MAIN RESULTS

We identified nine potentially eligible RCTs, three of which met our inclusion criteria. One trial compared Trizivir to efavirenz (an NNRTI) plus two or three NRTIs; the second trial compared Trizivir to a treatment based on the PI nelfinavir; and the third compared Trizivir to atazanavir (a PI) plus two NRTIs. Overall, there was no significant difference in the incidence of virological failure between participants on Trizivir and those on PI-based or NNRTI-based therapy (three trials, N=1687; RR 1.14, 95% CI 0.56 to 2.32). However, there was significant heterogeneity between the results of the three trials (heterogeneity P=0.009, I(2)=79%), with a significant increase in virological failure for Trizivir compared to efavirenz (N=1147; RR 1.93, 95% CI 1.46 to 2.55) but no difference between Trizivir and PIs (two trials, N=540; RR 0.82, 95% CI 0.50 to 1.36). We found no significant differences between Trizivir and either the PI or NNRTI on CD4+ cell counts (standardized mean difference -0.01, 95% CI -0.11 to 0.09, heterogeneity P=0.59, I(2)=0%), severe adverse events (RR 1.41, 95% CI 0.61 to 3.25, heterogeneity P=0.03, I(2)=73%) and hypersensitivity reactions (RR 4.04, 95% CI 0.41 to 40.02, heterogeneity P=0.03, I(2)=72%). Only the studies involving PIs reported the effect of the treatment regimens on the lipid profile. One study found that at 96 weeks, the mean increase in total cholesterol from baseline was significantly lower with Trizivir than with nelfinavir, but there were no significant differences with triglyceride levels. The second study found the fasting lipid profile to be comparable in both the Trizivir and atazanavir arms at 48 weeks.

AUTHORS' CONCLUSIONS

Our findings indicate that Trizivir remains a viable option for initiating antiretroviral therapy, especially in HIV-infected patients with pre-existing hyperlipidaemia and those who do not tolerate ritonavir.