When should antiretroviral therapy for HIV be started?

Effect of characteristics on the clinical course at the initiation of treatment for human immunodeficiency virus infection using dimensionality reduction

The beginning of human immunodeficiency virus (HIV) infection treatment depends on various factors, which are significantly correlated with the initial CD4 cell number. However, a covariate correlation between these factors may not reflect the correct outcome variable. Thus, we evaluated the effects of a combination of fixed factors (reduced dimensions), which determine when to start treatment for the first time, on short-term outcome, long-term outcome, and survival, considering correlations between factors. Multiple correspondence analysis was performed on variables obtained from 925 patients who participated in a Korean HIV/acquired immunodeficiency syndrome cohort study (2006-2017). Five reduced dimension groups were derived according to clinical data, viral load, CD4 cell count at diagnosis, initial antiretroviral therapy, and others. The dimension group with high initial viral loads (55,000 copies/mL) and low CD4 cell counts (< 200 cells/mm³) should start treatment promptly after diagnosis. Groups with high initial CD4 cell counts (> 350 cells/mm³) that did not require immediate treatment according to previous guidelines had a higher failure rate for long-term relative CD4 recovery. Our results highlight the importance of early diagnosis and treatment to positively influence long-term disease outcomes, even if the initial immune status is poor, given the patient's combination of early diagnostic symptoms.

Trajectories of Viral Suppression in People Living With HIV Receiving Coordinated Care: Differences by Comorbidities

BACKGROUND

In March of 2013, the Los Angeles County (LAC) Division of HIV and STD Programs implemented a clinic-based Medical Care Coordination (MCC) Program to increase viral suppression (VS) (<200 c/mL) among people living with HIV (PLWH) at high risk for poor health outcomes.

OBJECTIVE

This study aimed to estimate trajectories of VS and to assess whether these trajectories differed by stimulant use, housing instability, and depressive symptom severity as reported by PLWH participating in MCC.

METHODS

Data represent 6408 PLWH in LAC receiving services from the MCC Program and were obtained from LAC HIV surveillance data matched to behavioral assessments obtained across 35 Ryan White Program clinics participating in MCC. Piecewise mixed-effects logistic regression with a random intercept estimated probabilities of VS from 12 months before MCC enrollment through 36 months after enrollment, accounting for time by covariate interactions for 3 comorbid conditions: housing instability, stimulant use, and depressive symptoms.

RESULTS

The overall probability of VS increased from 0.35 to 0.77 within the first 6 months in the MCC Program, and this probability was maintained up to 36 months after enrollment. Those who reported housing instability, stimulant use, or multiple comorbid conditions did not achieve the same probability of VS by 36 months as those with none of those comorbidities.

CONCLUSIONS

Findings suggest that MCC improved the probability of VS for all patient groups regardless of the presence of comorbidities. However, those with comorbid conditions will still require increased support from patient-centered programs to address disparities in VS.

Inhibition of HIV-1 by a Lentiviral Vector with a Novel Tat-Inducible Expression System and a Specific Tropism to the Target Cells

Today, lentiviral vectors are favorable vectors for RNA interference delivery in anti-HIV therapeutic approaches. Nevertheless, problems such as the specific recognition of target cells and uncontrolled expression of the transgene can restrict their use in vivo. Herein we present a new HIV-inducible promoter to express anti-HIV short hairpin RNA (shRNA) by RNA Pol II in mammalian cells. We likewise showed a novel third-generation lentiviral vector system with more safety and a specific tropism to the target cells. The new promoter, CkRhsp, was constructed from the chicken β-actin core promoter with the R region of HIV-1 long terminal repeat fused upstream of minimal hsp70 promoter. This system was induced by HIV-1 Tat, and activates transcription of two shRNAs against two conserved regions of HIV-1 transcripts produced in two steps of the virus life cycle. We also mimicked HIV-1 cell tropism by using the HIV-1 envelope in structure of third-generation lentiviral vector. The new fusion promoter efficiently expressed shRNA in a Tat-inducible manner. HIV-1 replication was inhibited in transient transfection and stable transduction assays. The new viral vector infected only CD4+cells. CkRhsp promoter may be safer than other inducible promoters for shRNA-mediated gene therapies against HIV. The use of the wild envelope in the vector packaging system may provide the specific targeting T lymphocytes and hematopoietic stem cells for anti-HIV-1 therapeutic approaches in vivo.

Optimal starting point for antiretroviral HIV treatment in a town in Cameroon: a randomised controlled study

Background

Optimal starting point for antiretroviral treatment (ART) has been uncertain.

Methods

Parallel group, single blind, randomised controlled study of adult HIV positive patients consulting at the Protestant Hospital, Ngaoundere, Cameroon in 2007-8. Simple randomisation of patients in WHO clinical stage 1-2 to start of ART early or deferred, i.e. when CD4 counts dropped below 350 versus 250 cells/mm³, or when they reached clinical stage 3-4. Clinical follow-up every three months were offered for all patients. Main outcomes were clinical stage, CD4 differences and mortality. Of 424 consulting patients, most were excluded, mainly because they were already in WHO stage 3-4. Forty-four patients were randomised.

Results

In the ‘early’ group two patients died and five were lost to follow-up. In the ‘deferred’ group, six patients died and nine were lost to follow-up (Hazard ratio for death by early compared to deferred treatment 0.26, 95% confidence interval 0.05-1.29). Of the patients lost to follow-up, three patients in the ‘early’ group and four patients in the ‘deferred’ group were known to be alive when the study ended. Fourteen patients in the early group and 11 in the deferred group started ART. Twenty-two patients were evaluated clinically six to seven months after the study period was terminated. Except for one patient with AIDS, these were all still in clinical stage 1-2.

Conclusions

In our small sample, relative risk for death did not differ significantly, but deferred treatment seemed to carry no increased survival or other clinical advantage. During the study period, other studies made WHO change its guidelines to conform to our early treatment. The tendency in our study lends support to this policy.

Trial registration

ISRCTN22114173

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-828) contains supplementary material, which is available to authorized users.

Should expectations about the rate of new antiretroviral drug development impact the timing of HIV treatment initiation and expectations about treatment benefits?

Background

Many analyses of HIV treatment decisions assume a fixed formulary of HIV drugs. However, new drugs are approved nearly twice a year, and the rate of availability of new drugs may affect treatment decisions, particularly when to initiate antiretroviral therapy (ART).

Objectives

To determine the impact of considering the availability of new drugs on the optimal initiation criteria for ART and outcomes in patients with HIV/AIDS.

Methods

We enhanced a previously described simulation model of the optimal time to initiate ART to incorporate the rate of availability of new antiviral drugs. We assumed that the future rate of availability of new drugs would be similar to the past rate of availability of new drugs, and we estimated the past rate by fitting a statistical model to actual HIV drug approval data from 1982–2010. We then tested whether or not the future availability of new drugs affected the model-predicted optimal time to initiate ART based on clinical outcomes, considering treatment initiation thresholds of 200, 350, and 500 cells/mm³. We also quantified the impact of the future availability of new drugs on life expectancy (LE) and quality-adjusted life expectancy (QALE).

Results

In base case analysis, considering the availability of new drugs raised the optimal starting CD4 threshold for most patients to 500 cells/mm³. The predicted gains in outcomes due to availability of pipeline drugs were generally small (less than 1%), but for young patients with a high viral load could add as much as a 4.9% (1.73 years) increase in LE and a 8% (2.43 QALY) increase in QALE, because these patients were particularly likely to exhaust currently available ART regimens before they died. In sensitivity analysis, increasing the rate of availability of new drugs did not substantially alter the results. Lowering the toxicity of future ART drugs had greater potential to increase benefit for many patient groups, increasing QALE by as much as 10%.

Conclusions

The future availability of new ART drugs without lower toxicity raises optimal treatment initiation for most patients, and improves clinical outcomes, especially for younger patients with higher viral loads. Reductions in toxicity of future ART drugs could impact optimal treatment initiation and improve clinical outcomes for all HIV patients.

Immunodeficiency at the start of combination antiretroviral therapy in low-, middle-, and high-income countries

OBJECTIVE

To describe the CD4 cell count at the start of combination antiretroviral therapy (cART) in low-income (LIC), lower middle-income (LMIC), upper middle-income (UMIC), and high-income (HIC) countries.

METHODS

Patients aged 16 years or older starting cART in a clinic participating in a multicohort collaboration spanning 6 continents (International epidemiological Databases to Evaluate AIDS and ART Cohort Collaboration) were eligible. Multilevel linear regression models were adjusted for age, gender, and calendar year; missing CD4 counts were imputed.

RESULTS

In total, 379,865 patients from 9 LIC, 4 LMIC, 4 UMIC, and 6 HIC were included. In LIC, the median CD4 cell count at cART initiation increased by 83% from 80 to 145 cells/μL between 2002 and 2009. Corresponding increases in LMIC, UMIC, and HIC were from 87 to 155 cells/μL (76% increase), 88 to 135 cells/μL (53%), and 209 to 274 cells/μL (31%). In 2009, compared with LIC, median counts were 13 cells/μL [95% confidence interval (CI): -56 to +30] lower in LMIC, 22 cells/μL (-62 to +18) lower in UMIC, and 112 cells/μL (+75 to +149) higher in HIC. They were 23 cells/μL (95% CI: +18 to +28 cells/μL) higher in women than men. Median counts were 88 cells/μL (95% CI: +35 to +141 cells/μL) higher in countries with an estimated national cART coverage >80%, compared with countries with <40% coverage.

CONCLUSIONS

Median CD4 cell counts at the start of cART increased 2000-2009 but remained below 200 cells/μL in LIC and MIC and below 300 cells/μL in HIC. Earlier start of cART will require substantial efforts and resources globally.

The 'Antiretrovirals, Sexual Transmission Risk and Attitudes' (ASTRA) study. Design, methods and participant characteristics

Life expectancy for people diagnosed with HIV has improved dramatically however the number of new infections in the UK remains high. Understanding patterns of sexual behaviour among people living with diagnosed HIV, and the factors associated with having condom-less sex, is important for informing HIV prevention strategies and clinical care. In addition, in view of the current interest in a policy of early antiretroviral treatment (ART) for all people diagnosed with HIV in the UK, it is of particular importance to assess whether ART use is associated with increased levels of condom-less sex. In this context the ASTRA study was designed to investigate current sexual activity, and attitudes to HIV transmission risk, in a large unselected sample of HIV-infected patients under care in the UK. The study also gathered background information on demographic, socio-economic, lifestyle and disease-related characteristics, and physical and psychological symptoms, in order to identify other key factors impacting on HIV patients and the behaviours which underpin transmission. In this paper we describe the study rationale, design, methods, response rate and the demographic characteristics of the participants. People diagnosed with HIV infection attending 8 UK HIV out-patient clinics in 2011-2012 were invited to participate in the study. Those who agreed to participate completed a confidential, self-administered pen-and-paper questionnaire, and their latest CD4 count and viral load test results were recorded. During the study period, 5112 eligible patients were invited to take part in the study and 3258 completed questionnaires were obtained, representing a response rate of 64% of eligible patients. The study includes 2248 men who have sex with men (MSM), 373 heterosexual men and 637 women. Future results from ASTRA will be a key resource for understanding HIV transmission within the UK, targeting prevention efforts, and informing clinical care of individuals living with HIV.

Rating evidence in treatment guidelines: a case example of when to initiate combination antiretroviral therapy (cART) in HIV-positive asymptomatic persons

Guidelines for the initiation of combination antiretroviral therapy (cART) in those living with HIV are provided by several national and international treatment guidelines committees. Following recent changes to some of these guidelines, there is now considerable variation between the guidelines in terms of the recommendations for initiation of cART among asymptomatic individuals with high (>350 cells/µl) CD4 cell counts. In this review we compare the schemes used for rating evidence by the various committees and assess the strengths and weaknesses of the available evidence for initiating cART at higher CD4 cell counts.

Can we stop AIDS with antiretroviral-based treatment as prevention?

Challenges to scaling up treatment as prevention (TasP) of HIV transmission are considerable in the developing-world context and include accessing at-risk populations, human resource shortages, adherence and retention in care, access to newer treatments, measurement of treatment effects, and long-term sustainable funding. Optimism about ending AIDS needs to be tempered by the realities of the logistic challenges of strengthening health systems in countries most affected and by balancing TasP with overall combination prevention approaches.

The unanswered question: when to initiate antiretroviral therapy in children with HIV infection

PURPOSE OF REVIEW

The question of when to initiate antiretroviral treatment for children is perhaps the most critical unanswered question in pediatric HIV therapeutics. With large numbers of children throughout the world acquiring HIV infection and with improved global access to HIV treatment it is particularly timely to consider the optimal time to initiate antiretroviral therapy in infants, children and adolescents.

RECENT FINDINGS

Early treatment can result in suppression of HIV viremia, immune preservation and prevention of disease progression. This must be balanced by the challenges of maintaining adherence to multidrug regimens, the risks of selecting drug-resistant virus, and long and short-term toxicities of medications.

SUMMARY

This review provides a framework within which to consider when to initiate children on antiretroviral treatment. A child's age and developmental status, where they live, and the goals and expectations for treatment provide a context for balancing the risks of disease progression with the risks of drug-related toxicities and viral resistance.

Considerations in the rationale, design and methods of the Strategic Timing of AntiRetroviral Treatment (START) study

BACKGROUND

Untreated human immunodeficiency virus (HIV) infection is characterized by progressive depletion of CD4+ T lymphocyte (CD4) count leading to the development of opportunistic diseases (acquired immunodeficiency syndrome (AIDS)), and more recent data suggest that HIV is also associated with an increased risk of serious non-AIDS (SNA) diseases including cardiovascular, renal, and liver diseases and non-AIDS-defining cancers. Although combination antiretroviral treatment (ART) has resulted in a substantial decrease in morbidity and mortality in persons with HIV infection, viral eradication is not feasible with currently available drugs. The optimal time to start ART for asymptomatic HIV infection is controversial and remains one of the key unanswered questions in the clinical management of HIV-infected individuals.

PURPOSE

In this article, we outline the rationale and methods of the Strategic Timing of AntiRetroviral Treatment (START) study, an ongoing multicenter international trial designed to assess the risks and benefits of initiating ART earlier than is currently practiced. We also describe some of the challenges encountered in the design and implementation of the study and how these challenges were addressed.

METHODS

A total of 4000 study participants who are HIV type 1 (HIV-1) infected, ART naïve with CD4 count > 500 cells/µL are to be randomly allocated in a 1:1 ratio to start ART immediately (early ART) or defer treatment until CD4 count is <350 cells/µL (deferred ART) and followed for a minimum of 3 years. The primary outcome is time to AIDS, SNA, or death. The study had a pilot phase to establish feasibility of accrual, which was set as the enrollment of at least 900 participants in the first year.

RESULTS

Challenges encountered in the design and implementation of the study included the limited amount of data on the risk of a major component of the primary endpoint (SNA) in the study population, changes in treatment guidelines when the pilot phase was well underway, and the complexities of conducting the trial in a geographically wide population with diverse regulatory requirements. With the successful completion of the pilot phase, more than 1000 participants from 100 sites in 23 countries have been enrolled. The study will expand to include 237 sites in 36 countries to reach the target accrual of 4000 participants.

CONCLUSIONS

START is addressing one of the most important questions in the clinical management of ART. The randomization provided a platform for the conduct of several substudies aimed at increasing our understanding of HIV disease and the effects of antiretroviral therapy beyond the primary question of the trial. The lessons learned from its design and implementation will hopefully be of use to future publicly funded international trials.

The first decade of antiretroviral therapy in Africa

The past decade has seen remarkable progress in increasing access to antiretroviral therapy in resource-limited settings. Early concerns about the cost and complexity of treatment were overcome thanks to the efforts of a global coalition of health providers, activists, academics, and people living with HIV/AIDS, who argued that every effort must be made to ensure access to essential care when millions of lives depended on it. The high cost of treatment was reduced through advocacy to promote access to generic drugs; care provision was simplified through a public health approach to treatment provision; the lack of human resources was overcome through task-shifting to support the provision of care by non-physicians; and access was expanded through the development of models of care that could work at the primary care level. The challenge for the next decade is to further increase access to treatment and support sustained care for those on treatment, while at the same time ensuring that the package of care is continuously improved such that all patients can benefit from the latest improvements in drug development, clinical science, and public health.

Development and validation of decision rules to guide frequency of monitoring CD4 cell count in HIV-1 infection before starting antiretroviral therapy

Background

Although CD4 cell count monitoring is used to decide when to start antiretroviral therapy in patients with HIV-1 infection, there are no evidence-based recommendations regarding its optimal frequency. It is common practice to monitor every 3 to 6 months, often coupled with viral load monitoring. We developed rules to guide frequency of CD4 cell count monitoring in HIV infection before starting antiretroviral therapy, which we validated retrospectively in patients from the Swiss HIV Cohort Study.

Methodology/Principal Findings

We built up two prediction rules (“Snap-shot rule” for a single sample and “Track-shot rule” for multiple determinations) based on a systematic review of published longitudinal analyses of CD4 cell count trajectories. We applied the rules in 2608 untreated patients to classify their 18 061 CD4 counts as either justifiable or superfluous, according to their prior ≥5% or <5% chance of meeting predetermined thresholds for starting treatment. The percentage of measurements that both rules falsely deemed superfluous never exceeded 5%. Superfluous CD4 determinations represented 4%, 11%, and 39% of all actual determinations for treatment thresholds of 500, 350, and 200×10⁶/L, respectively. The Track-shot rule was only marginally superior to the Snap-shot rule. Both rules lose usefulness for CD4 counts coming near to treatment threshold.

Conclusions/Significance

Frequent CD4 count monitoring of patients with CD4 counts well above the threshold for initiating therapy is unlikely to identify patients who require therapy. It appears sufficient to measure CD4 cell count 1 year after a count >650 for a threshold of 200, >900 for 350, or >1150 for 500×10⁶/L, respectively. When CD4 counts fall below these limits, increased monitoring frequency becomes advisable. These rules offer guidance for efficient CD4 monitoring, particularly in resource-limited settings.

Postexposure prophylaxis, preexposure prophylaxis or universal test and treat: the strategic use of antiretroviral drugs to prevent HIV acquisition and transmission

This review considers the use of antiretroviral drugs specifically to prevent HIV transmission. Antiretroviral therapy (ART) can be implemented for the protection of uninfected individuals both before (preexposure prophylaxis) and after (postexposure prophylaxis) exposure to HIV infection. Preexposure prophylaxis may be used coitally dependently when individuals are intermittently exposed or by continuous daily dosing for those constantly exposed; postexposure prophylaxis is used in 28-day courses. Alternatively, ART can be used strategically to reduce the viral load and consequent infectiousness of an HIV-infected individual, thereby limiting the risk of onward viral transmission. A policy of universal HIV testing to enhance the identification of all HIV-positive individuals followed by immediate treatment of all HIV-positive individuals, irrespective of their CD4 cell counts (universal test and treat), has been postulated as a potential tool capable of reducing HIV incidence at a population level. This concept represents a paradigm shift in the use of ART, targeting infectious individuals for prevention rather than protecting uninfected exposed populations. This strategy could have the advantage of preventing transmission and reducing HIV incidence at a population level, as well as delivering universal access to therapy for all people living with HIV and AIDS, potentially eliminating mother-to-child HIV transmission and limiting concomitant diseases such as tuberculosis. This review critically examines the scientific basis of ART for HIV prevention, summarizing the risks and opportunities of the potential expansion of ART for prevention. Specifically, we consider the evidences for and against targeting HIV-uninfected individuals compared with enhanced HIV testing and treatment of HIV-infected individuals in terms of impact on viral transmission.

Understanding people who have never received HIV medical care: a population-based approach

A substantial number of people living with human immunodeficiency virus (HIV) have never received HIV medical care despite the benefits of early entry to care. The United States has no population-based system that can be used to estimate the number of people who have never received HIV care or to monitor the reasons that care is delayed. Although local efforts to describe unmet need and barriers to care have been informative, nationally representative data are needed to increase the number of people who enter care soon after diagnosis. Legal requirements to report all CD4 counts and all HIV viral load levels (indicators of HIV care) in most states now make national estimates of both care entry and non-entry feasible. The Centers for Disease Control and Prevention (CDC) and five state and local health department jurisdictions are testing and evaluating methods for a standardized supplemental HIV surveillance system to characterize HIV-infected people across the U.S. who have not entered HIV care after their diagnosis. This article reviews the context, rationale, and potential contributions of a nationally representative surveillance system to monitor delays in receiving HIV care, and provides data from the formative phase of the CDC pilot project.

Initiating patients on antiretroviral therapy at CD4 cell counts above 200 cells/microl is associated with improved treatment outcomes in South Africa

OBJECTIVES

To compare treatment outcomes by starting CD4 cell counts using data from the Comprehensive International Program of Research on AIDS-South Africa trial.

DESIGN

An observational cohort study.

METHODS

Patients presenting to primary care clinics with CD4 cell counts below 350 cells/microl were randomized to either doctor or nurse-managed HIV care and followed for at least 2 years after antiretroviral therapy (ART) initiation. Clinical and laboratory outcomes were compared by baseline CD4 cell counts.

RESULTS

Eight hundred and twelve patients were followed for a median of 27.5 months and 36% initiated ART with a CD4 cell count above 200 cells/microl. Although 10% of patients failed virologically, the risk was nearly double among those with a CD4 cell count of 200 cells/microl or less vs. above 200 cells/microl (12.2 vs. 6.8%). Twenty-one deaths occurred, with a five-fold increased risk for the low CD4 cell count group (3.7 vs. 0.7%). After adjustment, those with a CD4 cell count of 200 cells/microl had twice the risk of death/virologic failure [hazard ratio 1.9; 95% confidence interval (CI), 1.1-3.3] and twice the risk of incident tuberculosis (hazard ratio 1.90; 95% CI, 0.89-4.04) as those above 200 cells/microl. Those with either a CD4 cell count of 200 cells/microl or less (hazard ratio 2.1; 95% CI, 1.2-3.8) or a WHO IV condition (hazard ratio 2.9; 95% CI, 0.93-8.8) alone had a two-to-three-fold increased risk of death/virologic failure vs. those with neither, but those with both conditions had a four-fold increased risk (hazard ratio 3.9; 95% CI, 1.9-8.1). We observed some decreased loss to follow-up among those initiating ART at less than 200 cells/microl (hazard ratio 0.79; 95% CI, 0.50-1.25).

CONCLUSION

Patients initiating ART with higher CD4 cell counts had reduced mortality, tuberculosis and less virologic failure than those initiated at lower CD4 cell counts. Our data support increasing CD4 cell count eligibility criteria for ART initiation.

Long-term increase in CD4+ T-cell counts during combination antiretroviral therapy for HIV-1 infection

OBJECTIVE

To inform guidelines concerning when to initiate combination antiretroviral therapy (ART), we investigated whether CD4(+) T-cell counts (CD4 cell counts) continue to increase over long periods of time on ART. Losses-to-follow-up and some patients discontinuing ART at higher CD4 cell counts hamper such evaluation, but novel statistical methods can help address these issues. We estimated the long-term CD4 cell count trajectory accounting for losses-to-follow-up and treatment discontinuations.

DESIGN

The study population included 898 US patients first initiating ART in a randomized trial (AIDS Clinical Trials Group 384); 575 were subsequently prospectively followed in an observational study (AIDS Clinical Trials Group Longitudinal Linked Randomized Trials).

METHODS

Inverse probability of censoring weighting statistical methods were used to estimate the CD4 cell count trajectory accounting for losses-to-follow-up and ART discontinuations, overall and for pretreatment CD4 cell count categories (<or=200, 201-350, 351-500, and >500 cells/microl).

RESULTS

Median CD4 cell count increased from 270 cells/microl pre-ART to an estimated 556 cells/microl at 3 and 532 cells/microl at 7 years after starting ART in analyses ignoring treatment discontinuations, and to 570 and 640 cells/microl, respectively, had all patients continued ART. However, even had ART been continued, an estimated 25, 9, 3, and 2% of patients with pretreatment CD4 cell counts of 200 or less, 201-350, 351-500, and more than 500 cells/microl would have had CD4 cell counts of 350 cells/microl or less after 7 years.

CONCLUSION

If patients remain on ART, CD4 cell counts increase in most patients for at least 7 years. However, the substantial percentage of patients starting therapy at low CD4 cell counts who still had low CD4 cell counts after 7 years provides support for ART initiation at higher CD4 cell counts.

When to start antiretroviral therapy in resource-limited settings: a human rights analysis

BACKGROUND

Recent evidence from developed and developing countries shows clear clinical and public health benefit to starting antiretroviral therapy (ART) earlier. While discussions about when to start ART have often focused on the clinical risks and benefits, the main issue is one of fair limit-setting. We applied a human rights framework to assess a policy of early treatment initiation according to the following criteria: public-health purpose; likely effectiveness; specificity; human rights burdens and benefits; potential for less restrictive approaches; and fair administration.

DISCUSSION

According to our analysis, a policy of earlier ART initiation would better serve both public health and human rights objectives. We highlight a number of policy approaches that could be taken to help meet this aim, including increased international financial support, alternative models of care, and policies to secure the most affordable sources of appropriate antiretroviral drugs.

SUMMARY

Widespread implementation of earlier ART initiation is challenging in resource-limited settings. Nevertheless, rationing of essential medicines is a restriction of human rights, and the principle of least restriction serves to focus attention on alternative measures such as adapting health service models to increase capacity, decreasing costs, and seeking additional international funding. Progressive realisation using well-defined steps will be necessary to allow for a phased implementation as part of a framework of short-term targets towards nationwide policy adoption, and will require international technical and financial support.

Cohort studies: to what extent can they inform treatment guidelines?

PURPOSE OF REVIEW

This review examines situations in which information from cohort studies has proved to be useful for the development of treatment guidelines.

RECENT FINDINGS

Although there are several reasons why randomized controlled trials (RCTs) are felt to provide the most robust evidence for treatment guidelines, they may suffer from insufficient duration of follow-up, inadequate power to consider differences in important adverse events and highly selected patient populations. Furthermore, as most RCTs are performed for licensing purposes, strategic treatment decisions often lack supportive evidence from RCTs. Although data from cohort studies may be used to complement information from RCTs, cohort studies themselves are susceptible to several biases (most notably confounding) which may limit their findings. However, in the HIV field, information from such studies has been influential in guiding decisions relating to when to start highly active antiretroviral therapy, what drugs to use in the initial highly active antiretroviral therapy regimen and when to switch highly active antiretroviral therapy should virological failure occur.

SUMMARY

Given the biases that may be present, caution should be exercised when interpreting findings from cohort studies, particularly if comparisons are made of treatment strategies that involve some element of patient or clinician choice.

HIV testing factors associated with delayed entry into HIV medical care among HIV-infected persons from eighteen states, United States, 2000-2004

Despite the importance of timely entry into care after HIV diagnosis, the timing of care entry has not been described recently in a large, diverse population of persons with HIV. Dates of HIV diagnosis and entry into HIV care were obtained by interview of HIV-infected adults, most of whom had entered care for HIV, in 18 U.S. states from 2000 through 2004. Time to care entry was analyzed as a dichotomous variable; delayed care entry was defined as care entry greater than 3 months after HIV diagnosis. Multivariable logistic regression models were used to describe HIV testing-related factors associated with delayed care entry. Among 3942 respondents, 28% had delayed care entry. Diagnostic testing-related characteristics associated with delayed care entry included anonymous and first-time HIV testing. Providers of HIV testing should be aware that those who test positive anonymously and those whose first HIV test is positive may have increased risk for delayed HIV care entry. Developing programs that reinforce timely linkage to HIV care, targeted at those at increased risk for delaying care entry, should be a public health priority.

Health-related beliefs and decisions about accessing HIV medical care among HIV-infected persons who are not receiving care

In the United States, the publically supported national HIV medical care system is designed to provide HIV medical care to those who would otherwise not receive such care. Nevertheless, many HIV-infected persons are not receiving medical care. Limited information is available from HIV-infected persons not currently in care about the reasons they are not receiving care. From November 2006 to February 2007, we conducted five focus groups at community-based organizations and health departments in five U.S. cities to elicit qualitative information about barriers to entering HIV care. The 37 participants were mostly male (n = 29), over the age of 30 (n = 34), and all but one had not received HIV medical care in the previous 6 months. The focus group discussions revealed health belief-related barriers that have often been overlooked by studies of access to care. Three key themes emerged: avoidance and disbelief of HIV serostatus, conceptions of illness and appropriate health care, and negative experiences with, and distrust of, health care. Our findings point to the potentially important influence of these health-related beliefs on individual decisions about whether to access HIV medical care. We also discuss the implications of these beliefs for provider-patient communication, and suggest that providers frame their communications with patients such that they are attentive to the issues identified by our respondents, to better engage patients as partners in the treatment process.

Early antiretroviral therapy: the role of cohorts

PURPOSE OF REVIEW

To review the data that contribute to the debate on the optimal time to initiate highly active antiretroviral therapy in HIV-infected individuals, with a focus on the information that is available from cohort studies.

RECENT FINDINGS

The findings from cohort studies generally support initiation of highly active antiretroviral therapy at CD4 cell counts more than 350 cells/microl. In particular, the findings that death rates among treated HIV-infected individuals are higher than those in the general population, and that the risks of AIDS and serious non-AIDS events are higher in those with lower CD4 cell counts (even when the count remains >350 cells/microl), suggest that earlier initiation of highly active antiretroviral therapy may prevent some excess morbidity and mortality. However, given the lack of adjustment for lead-time bias in many analyses, the potential for residual confounding and the possible incomplete ascertainment of relevant outcomes in cohorts, it cannot be concluded that the benefits of highly active antiretroviral therapy when started at higher CD4 cell counts will outweigh the possible detrimental effects.

SUMMARY

Whereas the data from cohort studies currently support initiation of highly active antiretroviral therapy at CD4 cell counts more than 350 cells/microl, there is an urgent need for data from randomized trials to inform this decision.

[Human immunodeficiency virus and AIDS-associated immune reconstitution syndrome. State of the art]

Since the arrival of highly active antiretroviral therapy (HAART), immune reconstitution syndrome (IRS) has become an increasingly more frequent complication in patients with human immunodeficiency virus (HIV) infection. This article presents a review of the available evidence on this subject, indexed in MEDLINE-PUBMED, BVS-BIREME, and BioMed Central. The review covers the definition, epidemiology, classification, and diagnostic criteria related to IRS. In addition, the clinical particularities of the most frequent etiologies are described, and a proposal for a therapeutic approach is formulated. The prognosis and future implications of this syndrome in the epidemiology of some infectious illnesses in the HIV-positive population are included. Several unresolved aspects are mentioned, such as those related to the pathophysiology of the condition, use of biomarkers for the diagnosis, and the need for evidence-based therapeutic algorithms to enable standardization of treatment for these patients.

Early treatment of HIV: implications for resource-limited settings

PURPOSE OF REVIEW

We review the current literature supporting adoption of higher CD4 thresholds for initiation of antiretroviral treatment and survey progress in adoption of early treatment policies in resource-limited settings. We highlight some of the challenges and opportunities implementation of early treatment will bring.

RECENT FINDINGS

The initial success of combination antiretroviral treatment resulted in the recommendation to treat early all individuals with HIV. However, the gradual realization that antiretroviral treatment was associated with toxicity led to a more tempered approach. Recent cohort studies and some clinical trials have shown that delaying treatment is associated with increased morbidity and mortality.

SUMMARY

Early treatment is routinely practiced in developed countries. Now, early treatment is being adopted as a strategy in many resource-limited settings. The implications of this policy shift are not known, but we predict early treatment will have important consequences for the health system, the individual, and the community. Whereas these consequences will bring significant challenges, the increased numbers of HIV-infected individuals on treatment will result in many new opportunities - antiretroviral treatment will become less expensive, systems to deliver chronic care will be strengthened, and the policy shift will focus greater attention on pregnant women and children. Finally, some authors postulate that early treatment may impact HIV transmission.

CD4+ T-cell percentage is an independent predictor of clinical progression in AIDS-free antiretroviral-naive patients with CD4+ T-cell counts >200 cells/mm3

BACKGROUND

The aim of this study was to evaluate the clinical prognostic value of the CD4+ T-cell percentage (%CD4), the CD4+/CD8+ T-cell ratio or the CD8+ T-cell count, in addition to the CD4+ T-cell count and viral load (VL) in antiretroviral-naive HIV-infected patients with CD4+ T-cell counts >200 cells/mm(3).

METHODS

Antiretroviral-naive patients (n=9,740) who were AIDS-free and had a CD4+ T-cell count >200 cells/mm(3) at their first visit after January 1997 were followed-up until treatment initiation or clinical progression (mean follow-up 17 months and 13,660 person-years). Poisson regression was used for statistical analyses.

RESULTS

Progression to AIDS-defining events (ADEs), serious ADEs and death occurred in 228 patients (crude rate 1.69 per 100 person-years), 105 patients (0.77 per 100 person-years) and 67 patients (0.49 per 100 person-years), respectively. Regarding progression to ADE, the data fit was improved when the model also included the %CD4 (Akaike's information criteria [AIC] 2,049) and, to a lesser extent, the CD4+/CD8+ T-cell ratio (AIC 2,053), in addition to CD4+ T-cell count and VL (AIC 2,056). After adjustment for VL and baseline characteristics, patients with CD4+ T-cell counts of 350-500 cells/mm(3) and %CD4<15% had an estimated incidence of ADE of 3 per 100 person-years, similar to that in patients with CD4+ T-cell counts of 200-350 cells/mm(3) and %CD4>15%. The %CD4 was also significantly associated with the risk of serious ADE. By contrast, %CD4, CD4+/CD8+ T-cell ratio or CD8+ T-cell count had no additional prognostic value for the risk of death.

CONCLUSIONS

In antiretroviral-naive HIV-infected patients with CD4+ T-cell counts >200 cells/mm(3), the %CD4 was predictive of the risk of clinical progression independently of CD4+ T-cell count and VL.

Should HIV therapy be started at a CD4 cell count above 350 cells/microl in asymptomatic HIV-1-infected patients?

PURPOSE OF REVIEW

The aim is to review the available data that contribute to the debate on the optimal time to initiate highly active antiretroviral therapy (HAART) in HIV-infected individuals with a CD4 cell count more than 350 cells/microl.

RECENT FINDINGS

Although few randomized data exist that can contribute to this debate, a number of findings from observational studies generally support earlier initiation of HAART. In particular, the findings that death rates remain higher in HIV-infected individuals than in uninfected individuals, even when successfully treated, and that both AIDS and several serious non-AIDS events are more common in those with a lower CD4 cell count (even when this count is above 350 cells/microl), suggest that earlier initiation of HAART may prevent much of the excess morbidity and mortality that remains in this patient group.

SUMMARY

Currently, the data would generally support initiation of HAART in patients with CD4 cell counts more than 350 cells/microl. However, given the strong potential for confounding in observational studies and the lack of adjustment for lead-time bias in many analyses, it is not possible to rule out possible long-term detrimental effects of earlier use of HAART until the results from fully powered randomized trials that directly address this issue become available.

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

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 microL, 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 microL.

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 microL was associated with higher rates of AIDS and death than starting therapy in the range 351-450 cells per microL (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 microL compared with initiation at 351-450 cells per microL).

INTERPRETATION

Our results suggest that 350 cells per microL should be the minimum threshold for initiation of antiretroviral therapy, and should help to guide physicians and patients in deciding when to start treatment.

The therapeutic implications of timely linkage and early retention in HIV care

Following HIV diagnosis, linkage to outpatient treatment, antiretroviral initiation, and longitudinal retention in care represent the foundation for successful treatment. While prior studies have evaluated these processes in isolation, a systematic evaluation of successive steps in the same cohort of patients has not yet been performed. To ensure optimal long-term outcomes, a better understanding of the interplay of these processes is needed. Therefore, a retrospective cohort study of patients initiating outpatient care at the University of Alabama at Birmingham 1917 HIV=AIDS Clinic between January 2000 and December 2005 was undertaken. Multivariable models determined factors associated with: late diagnosis=linkage to care (initial CD4 < 350 cells=mm3), timely antiretroviral initiation, and retention across the first two years of care. Delayed linkage was observed in two-thirds of the overall sample (n = 567) and was associated with older age (odds ratio [OR] = 1.31 per 10 years; 95%confidence interval [CI] = 1.06-1.62) and African American race (OR = 2.45; 95% CI = 1.60-3.74). Attending all clinic visits (hazard ratio [HR] = 6.45; 95% CI = 4.47-9.31) and lower initial CD4 counts led to earlier antiretroviral initiation. Worse retention in the first 2 years was associated with younger age (OR = 0.68 per 10 years;95% CI = 0.56-0.83), higher baseline CD4 count, and substance abuse (OR = 1.78; 95% CI = 1.16-2.73). Interventions to improve timely HIV diagnosis and linkage to care should focus on older patients and African Americans while efforts to improve retention should address younger patients, those with higher baseline CD4 counts, and substance abuse. Missed clinic visits represent an important obstacle to the timely initiation of antiretroviral therapy. These data inform development of interventions to improve linkage and retention in HIV care, an emerging area of growing importance.

Patients presenting with AIDS in the HAART era: a collaborative cohort analysis

OBJECTIVE

Many patients infected with HIV still present with an AIDS diagnosis. The aim of this study was to evaluate the virological, immunological and clinical outcomes of HAART in these patients.

DESIGN

The present study was a multi-cohort study. All patients with an AIDS diagnosis between 30 days before and 14 days after HIV diagnosis, recruited between 1997 and 2004 from eight hospital cohorts, were evaluated.

RESULTS

A total of 760 patients were included [268 (35.3%) had pneumocystis and 168 (22.1%) tuberculosis]. Six hundred and twenty-four patients (82.1%) started HAART a median of 31 days after HIV diagnosis. One hundred and fifty-three patients started a nonnucleoside transcriptase inhibitor-based regimen (20.1%), 409 a protease inhibitor-based regimen (53.8%) and 62 other regimens (8.2%). In adjusted analyses, HAART was started sooner in more recent years, in patients with lower CD4 cell count and in those with Kaposi's sarcoma, whereas it was started later in those with tuberculosis. Five hundred and five patients (89%) attained a viral load of less than 500 copies/ml. The factors associated with a better virological response were later calendar year, lower initial viral load and cytomegalovirus disease. Virological rebound was more common in those receiving nucleoside reverse transcriptase inhibitor-based regimens, in those with tuberculosis and in earlier calendar years. One hundred and twenty-five (16%) patients died; 61 had received HAART (48.6%). Mortality was more likely in those who were older, those with a higher viral load at diagnosis, those with nonsexual HIV risks and those with lower CD4 cell count and haemoglobin levels over follow-up.

CONCLUSION

Virological suppression was achieved in most AIDS patients, though mortality remains high in these individuals.

HIV infection

INTRODUCTION

Infection with the human immunodeficiency virus (HIV) usually leads to 8-10 years of asymptomatic infection before immune function deteriorates and AIDS develops. Without treatment, about 50% of infected people will die of AIDS over 10 years. With treatment, prognosis depends on age, CD4 cell count, and initial viral load.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of preventive interventions? What are the effects of different antiretroviral drug treatment regimens in HIV infection? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2007 (BMJ Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 17 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: combination treatments containing either CCR5 inhibitors or fusion inhibitors; early diagnosis and treatment of sexually transmitted diseases (STDs); early and delayed antiretroviral treatment using triple antiretroviral regimens; non-nucleoside reverse transcriptase inhibitor (NNRTI) based triple regimens; nucleoside reverse transcriptase inhibitor (NRTI) and protease inhibitor-based triple regimens (standard, and boosted); post-exposure prophylaxis in healthcare workers; and presumptive mass treatment of sexually transmitted diseases (STDs).

Major clinical outcomes in antiretroviral therapy (ART)-naive participants and in those not receiving ART at baseline in the SMART study

BACKGROUND

The SMART study randomized 5,472 human immunodeficiency virus (HIV)-infected patients with CD4+ cell counts >350 cells/microL to intermittent antiretroviral therapy (ART; the drug conservation [DC] group) versus continuous ART (the viral suppression [VS] group). In the DC group, participants started ART when the CD4+ cell count was <250 cells/microL. Clinical outcomes in participants not receiving ART at entry inform the early use of ART.

METHODS

Patients who were either ART naive (n=249) or who had not been receiving ART for >or= 6 months (n=228) were analyzed. The following clinical outcomes were assessed: (i) opportunistic disease (OD) or death from any cause (OD/death); (ii) OD (fatal or nonfatal); (iii) serious non-AIDS events (cardiovascular, renal, and hepatic disease plus non-AIDS-defining cancers) and non-OD deaths; and (iv) the composite of outcomes (ii) and (iii).

RESULTS

A total of 477 participants (228 in the DC group and 249 in the VS group) were followed (mean, 18 months). For outcome (iv), 21 and 6 events occurred in the DC (7 in ART-naive participants and 14 in those who had not received ART for >or= 6 months) and VS (2 in ART-naive participants and 4 in those who had not received ART for 6 months) groups, respectively. Hazard ratios for DC vs. VS by outcome category were as follows: outcome (i), 3.47 (95% confidence interval [CI], 1.26-9.56; p=.02); outcome (ii), 3.26 (95% CI, 1.04-10.25; p=.04); outcome (iii), 7.02 (95% CI, 1.57-31.38; p=.01); and outcome (iv), 4.19 (95% CI, 1.69-10.39; p=.002 ).

CONCLUSIONS

Initiation of ART at CD4+ cell counts >350 cells/microL compared with <250 cells/microL may reduce both OD and serious non-AIDS events. These findings require validation in a large, randomized clinical trial.

The impact of HIV tropism on decreases in CD4 cell count, clinical progression, and subsequent response to a first antiretroviral therapy regimen

BACKGROUND

Human immunodeficiency virus (HIV) uses 2 distinct chemokine receptors, CCR5 (R5) or CXCR4 (X4), during entry. Viruses may be R5 tropic, X4 tropic, or dual/mixed (D/M) tropic. R5-tropic virus predominates at high CD4 cell counts, with the number of X4-tropic strains increasing as CD4 cell count decreases.

METHODS

We investigated the relationship between tropism and decreases in CD4 cell count before antiretroviral therapy initiation, the frequency of clinical events, and responses to antiretroviral therapy in a cohort of treatment-naive patients.

RESULTS

Four hundred two treatment-naive patients underwent tropism determination; 326 harbored R5-tropic virus, and 76 harbored X4- or D/M-tropic virus. After adjustment for baseline characteristics, the rate of decrease in CD4 cell count was significantly greater in patients infected with X4- or D/M-tropic virus at 12 months (P=.026). Two hundred twenty-nine individuals infected with R5-tropic virus and 60 individuals infected with X4- or D/M-tropic virus commenced antiretroviral therapy between tropism testing and the time of data analysis. Time to viral suppression and the proportion of patients achieving viral suppression were similar at 6, 12, and 24 months. CD4 cell count increases were similar. Clinical events were significantly more common in the group infected with X4- or D/M-tropic virus. Multivariate analysis demonstrated a relative risk of experiencing a clinical event of 2.56 (95% confidence interval, 1.37-4.76; P=.003) among patients infected with X4- or D/M-tropic virus.

CONCLUSIONS

The presence of D/M- or X4-tropic virus has a deleterious effect on CD4 cell count decrease and risk of clinical disease. Response to standard antiretroviral therapy is not affected by viral tropism.

Current CD4 cell count and the short-term risk of AIDS and death before the availability of effective antiretroviral therapy in HIV-infected children and adults

BACKGROUND

Currently, there are no comparable estimates of the short-term risk of disease progression in the absence of effective antiretroviral therapy for human immunodeficiency virus (HIV)-infected adults and children.

METHODS

A joint analysis of 2 large studies of children with vertically acquired HIV infection (the HIV Paediatric Prognostic Markers Collaborative Study) and adults with seroconversion (the CASCADE [Concerted Action on Sero-Conversion to AIDS and Death in Europe] collaboration) was conducted. Follow-up was censored at the end of 1995, before the introduction of combination antiretroviral therapy. The incidence rates of death and AIDS or death (AIDS/death) were estimated on the basis of age and current CD4 cell count.

RESULTS

A total of 1260 deaths (over 20,500 person-years of follow-up) and 1894 initial AIDS events (over 17,200 person-years of follow-up) were observed among 6741 patients (3244 children [i.e., patients < or =15 years of age] and 3497 adults). Young children (age, <5 years) experienced high morbidity and mortality rates. After adjustment for the CD4 cell count, the effect of age on disease progression was not significant among older children, whereas the risk increased markedly in association with increasing age among adults. Death rates were similar among older children and adults aged approximately 20 years, as were the rates of progression to AIDS/death when cases of serious recurrent bacterial infection, which has a more restrictive case definition in adults, were excluded.

CONCLUSIONS

Similar CD4 cell count criteria for initiation of antiretroviral therapy can be applied to adults and children > or = 5 years of age.

Use of WHO clinical stage for assessing patient eligibility to antiretroviral therapy in a routine health service setting in Jinja, Uganda

In a routine service delivery setting in Uganda, we assessed the ability of the WHO clinical stage to accurately identify HIV-infected patients in whom antiretroviral therapy should be started. Among 4302 subjects screened for ART, the sensitivity and specificity (95% CI) of WHO stage III, IV against a CD4 count < 200 x 106/l were 52% (50, 54%) and 68% (66, 70%) respectively. Plasma viral load was tested in a subset of 1453 subjects in whom ART was initiated. Among 938 subjects with plasma viral load of 100,000 copies or more, 391 (42%, 95% CI 39, 45%) were at WHO stage I or II. In this setting, a large number of individuals could have been denied access to antiretroviral therapy if eligibility to ART was assessed on the basis of WHO clinical stage. There is an urgent need for greater CD4 count testing and evaluation of the utility of plasma viral load prior to initiation of ART to accompany the roll-out of ART.

Genetic therapies against HIV

Highly active antiretroviral therapy prolongs the life of HIV-infected individuals, but it requires lifelong treatment and results in cumulative toxicities and viral-escape mutants. Gene therapy offers the promise of preventing progressive HIV infection by sustained interference with viral replication in the absence of chronic chemotherapy. Gene-targeting strategies are being developed with RNA-based agents, such as ribozymes, antisense, RNA aptamers and small interfering RNA, and protein-based agents, such as the mutant HIV Rev protein M10, fusion inhibitors and zinc-finger nucleases. Recent advances in T-cell-based strategies include gene-modified HIV-resistant T cells, lentiviral gene delivery, CD8(+) T cells, T bodies and engineered T-cell receptors. HIV-resistant hematopoietic stem cells have the potential to protect all cell types susceptible to HIV infection. The emergence of viral resistance can be addressed by therapies that use combinations of genetic agents and that inhibit both viral and host targets. Many of these strategies are being tested in ongoing and planned clinical trials.

Clinical progression rates by CD4 cell category before and after the initiation of combination antiretroviral therapy (cART)

Objective

Rates of AIDS defining event (ADE), serious ADE and death by CD4 and HIV RNA categories before and after combination antiretroviral therapy (cART) initiation are lacking for high CD4 counts.

Methods

Event rates were estimated within CD4 cell strata using a Poisson regression model adjusting for sex, exposure category, age, and current HIV RNA (<4, 4-4.99, ≥5 log copies/ml), and including an interaction term between the CD4 cell count and cART indicator.

Results

7317 and 6376 persons contributed to "naïve " and "cART " groups respectively, of whom 3911 contributed to both. At the same CD4 level, the risk of ADE was nearly 2 fold higher during naive follow-up compared to cART for CD4 <500 cells/mm³. However, after adjustment for current HIV RNA, the risk of ADE became similar for both groups except for CD4 count <200 cells/mm³ when it is 35% (6-72%) higher for naives. The same results were observed for the risk of serious ADE. There was no evidence of a difference in risk of death between naive and cART follow-up at specific CD4 categories even after adjustment for HIV RNA.

Conclusion

Within CD4 cell strata above 200 cells/mm³, the risk of ADE before ART initiation is higher than it is following cART initiation.

HIV diagnosis at CD4 count above 500 cells/mm3 and progression to below 350 cells/mm3 without antiretroviral therapy

A trial to evaluate the risks and benefits of initiation of antiretroviral therapy (ART) in patients with high CD4 count (eg, > or =500 cells/mm3), in comparison with deferral (eg, to <350 cells/mm3), merits consideration. Two issues for consideration in designing such a trial are the proportion of patients seen in clinics who present with high CD4 count and the time it will take for those randomized to deferring ART to reach a level where ART must be initiated. Among 13,572 patients in the UK CHIC Study presenting since 1996, 3631 (27%) had a count > or =500 cells/mm3. Among 4268 ART-naive patients with at least one CD4 count in the 500 to 650 cells/mm3 range, the median time to <350 cells/mm3 (or start of ART) was 2.5 years, with a range of 2.1 to 3.1 years depending on the analysis approach. Viral load at baseline was a strong predictor of the time taken for the CD4 count to reach <350 cells/mm3, with the median ranging from 0.7 years in those with viral load > or =500,000 copies/mL to 4.7 years in those with <1000 copies/mL. This provides timely background data on ART-naive patients seen in clinical practice to support design of a trial to compare immediate with deferred ART in people with high CD4 count.