The search for data on when to start treatment for HIV infection

Effects of early versus delayed initiation of antiretroviral treatment on clinical outcomes of HIV-1 infection: results from the phase 3 HPTN 052 randomised controlled trial

BACKGROUND

Use of antiretroviral treatment for HIV-1 infection has decreased AIDS-related morbidity and mortality and prevents sexual transmission of HIV-1. However, the best time to initiate antiretroviral treatment to reduce progression of HIV-1 infection or non-AIDS clinical events is unknown. We reported previously that early antiretroviral treatment reduced HIV-1 transmission by 96%. We aimed to compare the effects of early and delayed initiation of antiretroviral treatment on clinical outcomes.

METHODS

The HPTN 052 trial is a randomised controlled trial done at 13 sites in nine countries. We enrolled HIV-1-serodiscordant couples to the study and randomly allocated them to either early or delayed antiretroviral treatment by use of permuted block randomisation, stratified by site. Random assignment was unblinded. The HIV-1-infected member of every couple initiated antiretroviral treatment either on entry into the study (early treatment group) or after a decline in CD4 count or with onset of an AIDS-related illness (delayed treatment group). Primary events were AIDS clinical events (WHO stage 4 HIV-1 disease, tuberculosis, and severe bacterial infections) and the following serious medical conditions unrelated to AIDS: serious cardiovascular or vascular disease, serious liver disease, end-stage renal disease, new-onset diabetes mellitus, and non-AIDS malignant disease. Analysis was by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT00074581.

FINDINGS

1763 people with HIV-1 infection and a serodiscordant partner were enrolled in the study; 886 were assigned early antiretroviral treatment and 877 to the delayed treatment group (two individuals were excluded from this group after randomisation). Median CD4 counts at randomisation were 442 (IQR 373-522) cells per μL in patients assigned to the early treatment group and 428 (357-522) cells per μL in those allocated delayed antiretroviral treatment. In the delayed group, antiretroviral treatment was initiated at a median CD4 count of 230 (IQR 197-249) cells per μL. Primary clinical events were reported in 57 individuals assigned to early treatment initiation versus 77 people allocated to delayed antiretroviral treatment (hazard ratio 0·73, 95% CI 0·52-1·03; p=0·074). New-onset AIDS events were recorded in 40 participants assigned to early antiretroviral treatment versus 61 allocated delayed initiation (0·64, 0·43-0·96; p=0·031), tuberculosis developed in 17 versus 34 patients, respectively (0·49, 0·28-0·89, p=0·018), and primary non-AIDS events were rare (12 in the early group vs nine with delayed treatment). In total, 498 primary and secondary outcomes occurred in the early treatment group (incidence 24·9 per 100 person-years, 95% CI 22·5-27·5) versus 585 in the delayed treatment group (29·2 per 100 person-years, 26·5-32·1; p=0·025). 26 people died, 11 who were allocated to early antiretroviral treatment and 15 who were assigned to the delayed treatment group.

INTERPRETATION

Early initiation of antiretroviral treatment delayed the time to AIDS events and decreased the incidence of primary and secondary outcomes. The clinical benefits recorded, combined with the striking reduction in HIV-1 transmission risk previously reported, provides strong support for earlier initiation of antiretroviral treatment.

FUNDING

US National Institute of Allergy and Infectious Diseases.

Life expectancy living with HIV: recent estimates and future implications

PURPOSE OF REVIEW

The life expectancy of people living with HIV has dramatically increased since effective antiretroviral therapy has been available, and still continues to improve. Here, we review the latest literature on estimates of life expectancy and consider the implications for future research.

RECENT FINDINGS

With timely diagnosis, access to a variety of current drugs and good lifelong adherence, people with recently acquired infections can expect to have a life expectancy which is nearly the same as that of HIV-negative individuals. Modelling studies suggest that life expectancy could improve further if there were increased uptake of HIV testing, better antiretroviral regimens and treatment strategies, and the adoption of healthier lifestyles by those living with HIV. In particular, earlier diagnosis is one of the most important factors associated with better life expectancy. A consequence of improved survival is the increasing number of people with HIV who are aged over 50 years old, and further research into the impact of ageing on HIV-positive people will therefore become crucial. The development of age-specific HIV treatment and management guidelines is now called for.

SUMMARY

Analyses on cohort studies and mathematical modelling studies have been used to estimate life expectancy of those with HIV, providing useful insights of importance to individuals and healthcare planning.

Impact of earlier HAART initiation on the immune status and clinical course of treated patients on the basis of cohort data of the German Competence Network for HIV/AIDS

PURPOSE

Hitherto, studies on highly active antiretroviral therapy (HAART) initiation have shown partly inconsistent results. Our study investigated the clinical course and course of immune status after HAART initiation at CD4-cell-count/μl of treated patients between 250 and 349 (group 1), compared to 350-449 (group 2), on the basis of the cohort of the Competence Network for HIV/AIDS (KompNet cohort).

METHODS

Patients had to be HAART-naïve. Medication had to start at the earliest in 1996, being at least triple combination therapy. The primary endpoints of death, first AIDS-defining illness and first drop of CD4-cell-count/μl below 200 were evaluated as censored event times between the initiation of HAART (t (0)) and the date of the first event/date of last observation. Probabilities of event-free intervals since t (0) were calculated by Kaplan-Meier estimation, compared by logrank tests. The results were adjusted for confounders using Cox regression. Additionally, incidences were estimated.

RESULTS

A total of 822 patients met the inclusion criteria (group 1: 526, group 2: 296), covering 4,133 patient years (py) overall. In group 1, 0.64 death cases/100 py were found, with the corresponding vale being 0.17 in group 2. In group 1, 1.38 AIDS-defining events/100 py occurred, whereas it was 0.78 in group 2. In group 1, 2.64 events of first drop of CD4-cell-count/μl below 200 occurred per 100 py, compared to 0.77 in group 2. Kaplan-Meier estimations showed borderline significant differences regarding death (p = 0.063), no differences regarding first AIDS-defining illness (p = 0.148) and distinct differences regarding the first drop of CD4-cell-count/μl below 200 (p = 0.0004).

CONCLUSIONS

The results gave a strong hint for a therapy initiation at higher CD4-cell-count/μl regarding the outcome of death in treated patients. A distinct benefit was shown regarding the first decline of CD4-cell-count/μl below 200.

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.

Effect of early versus deferred antiretroviral therapy for HIV on survival

BACKGROUND

The optimal time for the initiation of antiretroviral therapy for asymptomatic patients with human immunodeficiency virus (HIV) infection is uncertain.

METHODS

We conducted two parallel analyses involving a total of 17,517 asymptomatic patients with HIV infection in the United States and Canada who received medical care during the period from 1996 through 2005. None of the patients had undergone previous antiretroviral therapy. In each group, we stratified the patients according to the CD4+ count (351 to 500 cells per cubic millimeter or >500 cells per cubic millimeter) at the initiation of antiretroviral therapy. In each group, we compared the relative risk of death for patients who initiated therapy when the CD4+ count was above each of the two thresholds of interest (early-therapy group) with that of patients who deferred therapy until the CD4+ count fell below these thresholds (deferred-therapy group).

RESULTS

In the first analysis, which involved 8362 patients, 2084 (25%) initiated therapy at a CD4+ count of 351 to 500 cells per cubic millimeter, and 6278 (75%) deferred therapy. After adjustment for calendar year, cohort of patients, and demographic and clinical characteristics, among patients in the deferred-therapy group there was an increase in the risk of death of 69%, as compared with that in the early-therapy group (relative risk in the deferred-therapy group, 1.69; 95% confidence interval [CI], 1.26 to 2.26; P<0.001). In the second analysis involving 9155 patients, 2220 (24%) initiated therapy at a CD4+ count of more than 500 cells per cubic millimeter and 6935 (76%) deferred therapy. Among patients in the deferred-therapy group, there was an increase in the risk of death of 94% (relative risk, 1.94; 95% CI, 1.37 to 2.79; P<0.001).

CONCLUSIONS

The early initiation of antiretroviral therapy before the CD4+ count fell below two prespecified thresholds significantly improved survival, as compared with deferred therapy.