Sonia Napravnik

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.

Late Presentation for Human Immunodeficiency Virus Care in the United States and Canada

BACKGROUND. Initiatives to improve early detection and access to human immunodeficiency virus (HIV) services have increased over time. We assessed the immune status of patients at initial presentation for HIV care from 1997 to 2007 in 13 US and Canadian clinical cohorts. METHODS. We analyzed data from 44,491 HIV-infected patients enrolled in the North American-AIDS Cohort Collaboration on Research and Design. We identified first presentation for HIV care as the time of first CD4(+) T lymphocyte (CD4) count and excluded patients who prior to this date had HIV RNA measurements, evidence of antiretroviral exposure, or a history of AIDS-defining illness. Trends in mean CD4 count (measured as cells/mm(3)) and 95% confidence intervals were determined using linear regression adjusted for age, sex, race/ethnicity, HIV transmission risk, and cohort. RESULTS. Median age at first presentation for HIV care increased over time (range, 40-43 years; P < .01), whereas the percentage of patients with injection drug use HIV transmission risk decreased (from 26% to 14%; P < .01) and heterosexual transmission risk increased (from 16% to 23%; P < .01). Median CD4 count at presentation increased from 256 cells/mm(3) (interquartile range, 96-455 cells/mm(3)) to 317 cells/mm(3) (interquartile range, 135-517 cells/mm(3)) from 1997 to 2007 (P < .01). The percentage of patients with a CD4 count > or = 350 cells/mm(3) at first presentation also increased from 1997 to 2007 (from 38% to 46%; P < .01). The estimated adjusted mean CD4 count increased at a rate of 6 cells/mm(3) per year (95% confidence interval, 5-7 cells/mm(3) per year). CONCLUSION. CD4 count at first presentation for HIV care has increased annually over the past 11 years but has remained <350 cells/mm(3), which suggests the urgent need for earlier HIV diagnosis and treatment.

Long-term consequences of the delay between virologic failure of highly active antiretroviral therapy and regimen modification

OBJECTIVE Studies have found that CD8 T-cell activation, as measured by CD38 expression, in HIV-1-infected individuals on suppressive therapy for longer than 12 months is not predictive of CD4 T-cell recovery. Owing to the fact that reconstitution of memory and naive T-cell populations occurs differentially over time, this study evaluated whether distinct memory/naive CD4 T-cell subsets correlated with CD38 on CD8 T-cells. MATERIALS AND METHODS Whole blood from 13 participants was used to evaluate activation phenotypic markers on CD8 lymphocytes and memory/naive phenotypes on CD4 lymphocytes. These HIV-1-infected individuals had stable CD4 cell counts for more than 1 year while on suppressive combination antiretroviral therapy. RESULTS The results demonstrate that CD4 central memory and naive cell populations contribute to the magnitude of CD4 T-cell reconstitution. CD4 central memory has a significant negative correlation with the percentage of CD38-activated CD8 T-cells. CONCLUSION This suggests that CD8 activation is important in CD4 recovery from a low CD4 T-cell nadir.Objectives:Current treatment guidelines recommend immediate modification of antiretroviral therapy in HIV-infected individuals with incomplete viral suppression. These recommendations have not been tested in observational studies or large randomized trials. We evaluated the consequences of delayed modification following virologic failure. Design/methods:We used prospective data from two clinical cohorts to estimate the effect of time until regimen modification following first regimen failure on all-cause mortality. The impact of regimen type was also assessed. As the effect of delayed switching can be confounded if patients with a poor prognosis modify therapy earlier than those with a good prognosis, we used a statistical methodology – marginal structural models – to control for time-dependent confounding. Results:A total of 982 patients contributed 3414 person-years of follow-up following first regimen failure. Delay until treatment modification was associated with an elevated hazard of all-cause mortality among patients failing a reverse transcriptase inhibitor-based regimen (hazard ratio per additional 3 months delay = 1.23, 95% confidence interval: 1.08, 1.40), but appeared to have a small protective effect among patients failing a protease inhibitor-based regimen (hazard ratio per additional 3 months delay = 0.93, 95% confidence interval: 0.87, 0.99). Conclusion:Delay in modification after failure of regimens that do not contain a protease inhibitor is associated with increased mortality. Protease inhibitor-based regimens are less dependent on early versus delayed switching strategies. Efforts should be made to minimize delay until treatment modification in resource-poor regions, where the majority of patients are starting reverse transcriptase inhibitor-based regimens and HIV RNA monitoring may not be available.

Randomized Study of the Safety and Efficacy of Fish Oil (Omega-3 Fatty Acid) Supplementation with Dietary and Exercise Counseling for the Treatment of Antiretroviral Therapy—Associated Hypertriglyceridemia

BACKGROUND Omega-3 fatty acids (fish oils) reduce fasting serum triglyceride levels and cardiovascular disease risk in individuals without HIV infection. Whether omega-3 fatty acid supplementation can reduce hypertriglyceridemia associated with antiretroviral therapy is not known. METHODS We conducted an open-label, randomized trial that enrolled 52 patients receiving > or =3 active antiretrovirals who had fasting triglyceride levels of >200 mg/dL and were randomized to receive nutritionist-administered dietary and exercise counseling with or without fish oil supplementation for 16 weeks. RESULTS Patients assigned to receive fish oil experienced a 25% mean decline in fasting triglyceride levels at week 4 (95% CI, -34.6% to -15.7% change), compared with a 2.8% mean increase among patients assigned to receive counseling alone (95% CI, -17.5% to +23.1% change) (P=.007). By week 16, the mean reduction in triglyceride levels in the fish oil arm remained significant, at 19.5% (95% CI, -34.9% to -4.0% change), whereas the mean decrease in the diet and exercise only arm was 5.7% (95% CI, -24.6% to +13.2% change); however, the difference between study arms was no longer statistically significant (P=.12). Low-density lipoprotein cholesterol levels had increased by 15.6% (95% CI, +4.8% to +26.4% change) at week 4 and by 22.4% (95% CI, +7.91% to +36.8% change) at week 16 in the fish oil arm but did not change in the diet and exercise only group. Fish oil was well tolerated; only 1 patient experienced treatment-limiting toxicity. Patients assigned to receive fish oil experienced a 25% mean decline in fasting triglyceride levels at week 4 (95% CI, -34.6% to -15.7% change), compared with a 2.8% mean increase in patients assigned to receive counseling alone (95% CI, -17.5% to 23.1% change) (P=.007). By week 16, the mean reduction in triglyceride levels in the fish oil arm remained significant, at 19.5% (95% CI, -34.9% to -4.0% change), whereas the mean decrease in the diet and exercise only arm was 5.7% (95% CI, -24.6% to 13.2% change); however, the difference between study arms was no longer statistically significant (P=.12). Low-density lipoprotein cholesterol levels had increased by 15.6% (95% CI, 4.8%-26.4% change) at week 4 and by 22.4% (95% CI, 7.91%-36.8% change) at week 16 in the fish oil arm but did not change in the diet and exercise only group. Fish oil was well tolerated; only 1 patient experienced treatment-limiting toxicity. CONCLUSIONS Supplementation with omega-3 fatty acids in combination with dietary and exercise counseling was well tolerated and reduced fasting triglyceride levels in patients receiving antiretrovirals. To what extent the increase in low-density lipoprotein cholesterol levels observed in patients assigned this intervention is attributable to omega-3 fatty acid supplementation and whether this increase attenuates any benefit in lowering triglyceride levels is unclear. Given these results, further investigation of omega-3 fatty acid supplementation for the treatment of hypertriglyceridemia in HIV-infected patients is warranted.

Gender difference in HIV RNA levels: a meta-analysis of published studies.

&NA; Plasma HIV RNA copy number is a strong prognostic marker of progression to AIDS in antiretroviral‐naive persons. Recent research suggests women have lower HIV RNA levels than comparable men. Because clinical care recommendations currently include HIV RNA thresholds as a guide to initiating antiretroviral therapy (ART), the authors undertook the present quantitative meta‐analysis to explore the relation between gender and plasma HIV RNA levels. A gender difference in HIV RNA levels was observed in the CD4‐unadjusted and ‐adjusted analyses. The summary estimate including only CD4‐adjusted results with the lowest heterogeneity indicated that on average, women have 41% lower plasma HIV RNA levels than men (‐.23 log10; 95% confidence interval [CI], ‐.16 to ‐.31 log10). Because numerous studies have found similar HIV disease progression rates in men and women, adjusted for CD4 but not HIV RNA, the present meta‐analysis supports the use of lower HIV RNA thresholds in women than in men to guide initiation of ART. Given the patient characteristics in the original studies used in this meta‐analysis, the results are most likely to apply to therapy‐naive persons with CD4 lymphocyte counts >200 cells/mm3, a subgroup for whom HIV RNA levels may strongly influence the decision to initiate therapy.

HIV-1 drug resistance evolution among patients on potent combination antiretroviral therapy with detectable viremia.

Many patients infected with HIV do not achieve or maintain virologic suppression below levels of detection while on potent combination antiretroviral therapy. The likelihood of emergence of incident mutations conferring reduced antiretroviral drug susceptibility was estimated among patients maintained on a stable regimen with ongoing detectable plasma HIV RNA levels. Ninety-eight HIV-infected patients were identified who had 2 genotypic antiretroviral resistance tests available. Poisson log-linear regression models were used to identify predictors and estimate incidence rates of number of acquired antiretroviral drug resistance mutations per person-year. At the 1st resistance test, 88% of patients had evidence of at least 1 mutation. Sixty percent of patients acquired at least 1 new mutation during a median of 9.3 months between consecutive resistance tests, with an incidence rate of 1.61 acquired mutations per person-year (95% CI: 1.36-1.90). Predictors of resistance evolution included average plasma HIV RNA level, HIV RNA slope, and number of mutations detected at the 1st resistance test. The likelihood of acquiring drug resistance mutations while remaining on potent combination antiretroviral therapy that does not confer complete suppression of HIV replication is relatively low and depends on the level of viral replication and prior resistance.

The Effect of Highly Active Antiretroviral Therapy on the Survival of HIV-Infected Children in a Resource-Deprived Setting: A Cohort Study

This observational cohort study by Andrew Edmonds and colleagues reports that treatment with highly active antiretroviral therapy (HAART) markedly improves the survival of HIV-infected children in Kinshasa, DRC, a resource-deprived setting.

Viremia Copy-Years Predicts Mortality Among Treatment-Naive HIV-Infected Patients Initiating Antiretroviral Therapy

BACKGROUND Cross-sectional plasma human immunodeficiency virus (HIV) viral load (VL) measures have proven invaluable for clinical and research purposes. However, cross-sectional VL measures fail to capture cumulative plasma HIV burden longitudinally. We evaluated the cumulative effect of exposure to HIV replication on mortality following initiation of combination antiretroviral therapy (ART). METHODS We included treatment-naive HIV-infected patients starting ART from 2000 to 2008 at 8 Center for AIDS Research Network of Integrated Clinical Systems sites. Viremia copy-years, a time-varying measure of cumulative plasma HIV exposure, were determined for each patient using the area under the VL curve. Multivariable Cox models were used to evaluate the independent association of viremia copy-years for all-cause mortality. RESULTS Among 2027 patients contributing 6579 person-years of follow-up, the median viremia copy-years was 5.3 log₁₀ copy × y/mL (interquartile range: 4.9-6.3 log₁₀ copy × y/mL), and 85 patients (4.2%) died. When evaluated separately, viremia copy-years (hazard ratio [HR] = 1.81 per log₁₀ copy × y/mL; 95% confidence interval [CI], 1.51-2.18 per log(10) copy × y/mL), 24-week VL (1.74 per log₁₀ copies/mL; 95% CI, 1.48-2.04 per log₁₀ copies/mL), and most recent VL (HR = 1.89 per log₁₀ copies/mL; 95% CI: 1.63-2.20 per log₁₀ copies/mL) were associated with increased mortality. When simultaneously evaluating VL measures and controlling for other covariates, viremia copy-years increased mortality risk (HR = 1.44 per log₁₀ copy × y/mL; 95% CI, 1.07-1.94 per log₁₀ copy × y/mL), whereas no cross-sectional VL measure was independently associated with mortality. CONCLUSIONS Viremia copy-years predicted all-cause mortality independent of traditional, cross-sectional VL measures and time-updated CD4+ T-lymphocyte count in ART-treated patients, suggesting cumulative HIV replication causes harm independent of its effect on the degree of immunodeficiency.

Virologic and immunologic response to HAART, by age and regimen class

Objective:To determine the impact of age and initial HAART regimen class on virologic and immunologic response within 24 months after initiation. Design:Pooled analysis of data from 19 prospective cohort studies in the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD). Methods:Twelve thousand, one hundred and ninety-six antiretroviral-naive adults who initiated HAART between 1998 and 2008 using a boosted protease inhibitor-based regimen or a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen were included in our study. Discrete time-to-event models estimated adjusted hazard odds ratios (aHOR) and 95% confidence intervals (CIs) for suppressed viral load (≤500 copies/ml) and, separately, at least 100 cells/μl increase in CD4 cell count. Truncated, stabilized inverse probability weights accounted for selection biases from discontinuation of initial regimen class. Results:Among 12 196 eligible participants (mean age = 42 years), 50% changed regimen classes after initiation (57 and 48% of whom initiated protease inhibitor and NNRTI-based regimens, respectively). Mean CD4 cell count at initiation was similar by age. Virologic response to treatment was less likely in those initiating using a boosted protease inhibitor [aHOR = 0.77 (0.73, 0.82)], regardless of age. Immunologic response decreased with increasing age [18–<30: ref; 30–<40: aHOR = 0.92 (0.85, 1.00); 40–<50: aHOR = 0.85 (0.78, 0.92); 50–<60: aHOR = 0.82 (0.74, 0.90); ≥60: aHOR = 0.74 (0.65, 0.85)], regardless of initial regimen. Conclusion:We found no evidence of an interaction between age and initial antiretroviral regimen on virologic or immunologic response to HAART; however, decreased immunologic response with increasing age may have implications for age-specific when-to-start guidelines.

Copy-Years Viremia as a Measure of Cumulative Human Immunodeficiency Virus Viral Burden

Plasma human immunodeficiency virus type 1 (HIV-1) viral load is a valuable tool for HIV research and clinical care but is often used in a noncumulative manner. The authors developed copy-years viremia as a measure of cumulative plasma HIV-1 viral load exposure among 297 HIV seroconverters from the Multicenter AIDS Cohort Study (1984-1996). Men were followed from seroconversion to incident acquired immunodeficiency syndrome (AIDS), death, or the beginning of the combination antiretroviral therapy era (January 1, 1996); the median duration of follow-up was 4.6 years (interquartile range (IQR), 2.7-6.5). The median viral load and level of copy-years viremia over 2,281 semiannual follow-up assessments were 29,628 copies/mL (IQR, 8,547-80,210) and 63,659 copies x years/mL (IQR, 15,935-180,341). A total of 127 men developed AIDS or died, and 170 survived AIDS-free and were censored on January 1, 1996, or lost to follow-up. Rank correlations between copy-years viremia and other measures of viral load were 0.56-0.87. Each log(10) increase in copy-years viremia was associated with a 1.70-fold increased hazard (95% confidence interval: 0.94, 3.07) of AIDS or death, independently of infection duration, age, race, CD4 cell count, set-point, peak viral load, or most recent viral load. Copy-years viremia, a novel measure of cumulative viral burden, may provide prognostic information beyond traditional single measures of viremia.