Both serum HIV type 1 RNA levels and CD4+ lymphocyte counts predict clinical outcome in HIV type 1-infected subjects with 200 to 500 CD4+ cells per cubic millimeter. AIDS Clinical Trials Group Study 175 Virology Study Team

Early Fungicidal Activity as a Candidate Surrogate Endpoint for All-Cause Mortality in Cryptococcal Meningitis: A Systematic Review of the Evidence

BACKGROUND

Cryptococcal meningitis (CM) is a leading cause of HIV-associated mortality. In clinical trials evaluating treatments for CM, biomarkers of early fungicidal activity (EFA) in cerebrospinal fluid (CSF) have been proposed as candidate surrogate endpoints for all- cause mortality (ACM). However, there has been no systematic evaluation of the group-level or trial-level evidence for EFA as a candidate surrogate endpoint for ACM.

METHODS

We conducted a systematic review of randomized trials in treatment of CM to evaluate available evidence for EFA measured as culture negativity at 2 weeks/10 weeks and slope of EFA as candidate surrogate endpoints for ACM. We performed sensitivity analysis on superiority trials and high quality trials as determined by Cochrane measures of trial bias.

RESULTS

Twenty-seven trials including 2854 patients met inclusion criteria. Mean ACM was 15.8% at 2 weeks and 27.0% at 10 weeks with no overall significant difference between test and control groups. There was a statistically significant group-level correlation between average EFA and ACM at 10 weeks but not at 2 weeks. There was also no statistically significant group-level correlation between CFU culture negativity at 2weeks/10weeks or average EFA slope at 10 weeks. A statistically significant trial-level correlation was identified between EFA slope and ACM at 2 weeks, but is likely misleading, as there was no treatment effect on ACM.

CONCLUSIONS

Mortality remains high in short time periods in CM clinical trials. Using published data and Institute of Medicine criteria, evidence for use of EFA as a surrogate endpoint for ACM is insufficient and could provide misleading results from clinical trials. ACM should be used as a primary endpoint evaluating treatments for cryptococcal meningitis.

Improved retention associated with community-based accompaniment for antiretroviral therapy delivery in rural Rwanda

BACKGROUND

Minimizing death and ensuring high retention and good adherence remain ongoing challenges for human immunodeficiency virus (HIV) treatment programs. We examined whether the addition of community-based accompaniment (characterized by daily home visits from a community health worker, directly observed treatment, nutritional support, transportation stipends, and other support as needed) to the Rwanda national model for antiretroviral therapy (ART) delivery would improve retention in care, viral load suppression, and change in CD4 count, relative to the national model alone.

METHODS

We conducted a prospective observational cohort study among 610 HIV-infected adults initiating ART in 1 of 2 programs in rural Rwanda. Psychosocial and clinical characteristics were recorded at ART initiation. Death, treatment retention, and plasma viral load were assessed at 1 year. CD4 count was evaluated at 6-month intervals. Multivariable regression models were used to adjust for baseline differences between the 2 populations.

RESULTS

Eighty-five percent and 79% of participants in the community-based and clinic-based programs, respectively, were retained with viral load suppression at 1 year. After adjusting for CD4 count, depression, physical health quality of life, and food insecurity, community-based accompaniment was protective against death or loss to follow-up during the first year of ART (hazard ratio, 0.17; 95% confidence interval [CI], .09-.35; P < .0001). In a second multivariable analysis, individuals receiving accompaniment were more likely to be retained with a suppressed viral load at 1 year (risk ratio: 1.15; 95% CI, 1.03-1.27; P = .01).

CONCLUSIONS

These findings indicate that community-based accompaniment is effective in improving retention, when added to a clinic-based program with fewer patient support mechanisms.

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.

Joint modeling of the clinical progression and of the biomarkers' dynamics using a mechanistic model

Joint models are used to rigorously explore the relationship between the dynamics of biomarkers and clinical events. In the context of HIV infection, where the multivariate dynamics of HIV-RNA and CD4 are complex, a mechanistic approach based on a system of nonlinear differential equations naturally takes into account the correlation between the biomarkers. Using data from a randomized clinical trial comparing dual antiretroviral therapy to a single drug regimen, a full maximum likelihood approach is proposed to explore the relationship between the evolution of the biomarkers and the time to a clinical event. The role of each marker as an independent predictor of disease progression is assessed. We show that the joint dynamics of HIV-RNA and CD4 captures the effect of antiretroviral treatment; the CD4 dynamics alone is found to capture most but not all of the treatment effect.

Cumulative viral load and virologic decay patterns after antiretroviral therapy in HIV-infected subjects influence CD4 recovery and AIDS

BACKGROUND

The impact of viral load (VL) decay and cumulative VL on CD4 recovery and AIDS after highly-active antiretroviral therapy (HAART) is unknown.

METHODS AND FINDINGS

Three virologic kinetic parameters (first year and overall exponential VL decay constants, and first year VL slope) and cumulative VL during HAART were estimated for 2,278 patients who initiated HAART in the U.S. Military HIV Natural History Study. CD4 and VL trajectories were computed using linear and nonlinear Generalized Estimating Equations models. Multivariate Poisson and linear regression models were used to determine associations of VL parameters with CD4 recovery, adjusted for factors known to correlate with immune recovery. Cumulative VL higher than the sample median was independently associated with an increased risk of AIDS (relative risk 2.38, 95% confidence interval 1.56-3.62, p<0.001). Among patients with VL suppression, first year VL decay and slope were independent predictors of early CD4 recovery (p = 0.001) and overall gain (p<0.05). Despite VL suppression, those with slow decay during the first year of HAART as well as during the entire therapy period (overall), in general, gained less CD4 cells compared to the other subjects (133 vs. 195.4 cells/µL; p = 0.001) even after adjusting for potential confounders.

CONCLUSIONS

In a cohort with free access to healthcare, independent of established predictors of AIDS and CD4 recovery during HAART, cumulative VL and virologic decay patterns were associated with AIDS and distinct aspects of CD4 reconstitution.

Cofactors for Low Serum Albumin Levels Among HIV-Infected Individuals in Southern India

Background and aims. Malnutrition and low serum albumin among human immunodeficiency virus (HIV)-infected individuals are cofactors for HIV disease progression. The present study aimed to identify the proportion of HIV-infected individuals with low serum albumin and the possible cofactors among highly active antiretroviral therapy (HAART) experienced and HAART naïve individuals. Methods. A total of 835 HIV-infected individuals (HAART-experienced, HAART-naïve) were included in the study. Results. Of the 835 individuals, 44.6% had normal (4.2-5.2 g/dL) and 55.4% had abnormal (<4.2 g/dL) albumin levels. The abnormal group had significantly lower body mass index (BMI) compared with the normal group (P = .02). Among those with abnormal albumin, 388 (84%) were HAART experienced compared with 239 (64%) with normal albumin (P < .001). Among the abnormal group, 259 (55.9%) had CD4 count <200 cells/mL as compared with 124 (33.3%) in the normal group (P < .001). Conclusions. CD4 count and lower were the major cofactors for low serum albumin among HIV-infected individuals. Therefore, serum albumin would be a useful biochemical test for HIV disease in resource-limited settings.

CCL3L1 and CCR5 influence cell-mediated immunity and affect HIV-AIDS pathogenesis via viral entry-independent mechanisms

Although host defense against human immunodeficiency virus 1 (HIV-1) relies mainly on cell-mediated immunity (CMI), the determinants of CMI in humans are poorly understood. Here we demonstrate that variations in the genes encoding the chemokine CCL3L1 and HIV coreceptor CCR5 influence CMI in both healthy and HIV-infected individuals. CCL3L1-CCR5 genotypes associated with altered CMI in healthy subjects were similar to those that influence the risk of HIV transmission, viral burden and disease progression. However, CCL3L1-CCR5 genotypes also modify HIV clinical course independently of their effects on viral load and CMI. These results identify CCL3L1 and CCR5 as major determinants of CMI and demonstrate that these host factors influence HIV pathogenesis through their effects on both CMI and other viral entry-independent mechanisms.

Haemoglobin and albumin as markers of HIV disease progression in the highly active antiretrovial therapy era: relationships with gender

OBJECTIVES

The aims of the study were to describe gender differences in haemoglobin and albumin and to investigate the prognostic value of these measurements in relation to highly active antiretroviral therapy (HAART).

METHODS

Anaemia was defined as haemoglobin <13.5 g/dL for men and <11.5 g/dL for women. Albumin <35 g/L was defined as hypoalbuminaemia. Proportional hazards models were used to describe relationships between these markers and HIV progression and death.

RESULTS

A total of 291 patients had pre-HAART and 1-year measurements. Mean haemoglobin and albumin levels pre-HAART were lower in women than in men (haemoglobin: 11.2 vs 13.2 g/dL, respectively, P<0.0001; albumin: 37.4 vs 40.2 g/L, respectively, P<0.0001), and a higher proportion of women were anaemic and hypoalbuminaemic compared with men. Despite a rise in both markers in the first year on HAART, mean haemoglobin levels remained lower by 2.08 g/dL (P<0.0001) and albumin by 2.88 g/L (P<0.0001) in women. In the 495 patients included in this analysis, haemoglobin and albumin levels were both significantly related to short-term risk of AIDS and death independently of CD4 count [hazards ratio (HR)=0.73/g/dL higher haemoglobin, 95% confidence interval (CI) 0.55-0.82, P<0.0001 and HR=0.87/g/L higher albumin, 95% CI 0.83-0.91, P<0.0001]. The prognostic value did not differ by gender.

CONCLUSIONS

Women were more likely to be anaemic and/or hypoalbuminaemic pre-HAART, but post-HAART increases were similar to those in men. Both haemoglobin and albumin were strong independent prognostic factors for risk of AIDS and death, regardless of gender.

HIV testing in 2006: issues and methods

Infection with HIV and subsequent development of AIDS is a pandemic. The Joint United Nations Program on HIV/AIDS together with the WHO and many relevant funding bodies demand that those infected should be reliably identified so that people who need, or will need, therapy may be provided for over time. This means that there is a renewed interest in testing for HIV and in laboratories' performances and quality. Whatever the conditions under which testing is performed, and whatever the levels of training, the tests and their outcomes must exhibit equivalent, high standards of performance and reliable results. This is regardless of whether testing is conducted in the most sophisticated laboratories (either diagnostic or transfusion screening) to voluntary testing and counseling centers where those conducting testing may not be technically trained. This is not currently the case, especially in some places where HIV is most prevalent. To achieve uniformly high performance standards, quality assurance programs are imperative, but currently not sufficiently valued to be well supported with adequate funding or human resources. Accurate HIV testing is a cornerstone of blood safety, diagnosis of infection, patient management and surveillance.

High frequency of highly active antiretroviral therapy modifications in patients with acute or early human immunodeficiency virus infection

STUDY OBJECTIVES

To examine the frequency of highly active antiretroviral therapy (HAART) modifications, the reasons for these modifications, and toxicities of these drugs in patients receiving their first HAART regimen after a diagnosis of acute (< 2 mo from infection) or early (2-12 mo) human immunodeficiency virus (HIV) infection.

PATIENTS

Fifty-one patients who were enrolled in the Acute Infection and Early Disease Research Program at a Baltimore, Maryland, site between January 1, 1998, and April 30, 2002, and who chose to start HAART.

MEASUREMENTS AND MAIN RESULTS

Time from initiation of therapy to first modification-defined as change in any HAART drug without an interruption in therapy or as simultaneous discontinuation of all drugs within the regimen-and time from initiation of therapy to reinitiation of therapy were recorded, as well as reasons for modification and reinitiation. With a median follow-up of 1,549 days, 21 (41%) of 51 patients received HAART continuously, but only 10 (20%) continued to receive their original regimen without any modification. Among the 41 patients (80%) who received modified therapy, the main reasons for the first modification were toxicity (16 patients), nonadherence (8), and new data on treatment efficacy or safety (8). Of 30 patients who stopped HAART, 18 restarted HAART at a later time.

CONCLUSION

The high frequency of treatment modification among patients treated after acute or early HIV infection underscores the importance of determining the usefulness of antiretroviral therapy early in HIV infection, and the need for more tolerable regimens if HAART is to be started at this stage.

Serum albumin as a prognostic indicator for HIV disease progression

Low albumin levels have been associated with HIV progression. The objective of this analysis was to confirm this association and to further examine the effect of albumin before and after HIV seroconversion on disease progression. The association was first examined among individuals already infected with HIV at entry into a community-based cohort (n = 453) and further assessed among HIV seroconverters with albumin concentrations measured after (n = 219) and before seroconversion (n = 138). The prognostic effect of albumin on AIDS, AIDS mortality, and all-cause mortality was examined using Cox regression. Among 453 HIV-infected individuals, albumin <35 g/liter was associated with faster progression to AIDS [adjusted relative hazard (ARH), 1.8; 95% confidence interval (CI), 1.2-2.8], AIDS mortality (ARH, 2.2; 95% CI, 1.3-3.8), and all-cause mortality (ARH, 2.4; 95% CI, 1.6-3.5). Analyses restricted to HIV seroconverters were similar. Preseroconversion levels of albumin did not predict outcomes, but HIV seroconversion appeared to lower albumin levels. These data show that albumin <35 g/liter after HIV seroconversion is associated with faster HIV disease progression and suggest that low albumin levels are probably a consequence of HIV infection rather than merely reflective of some individuals inherently having low albumin levels.

Synchronous kinetics of CD4+ lymphocytes and viral load before the onset of oral candidosis and hairy leukoplakia in a cohort of Mexican HIV-infected patients

An observational, prospective, longitudinal cohort study was performed at the AIDS Clinic of a tertiary care institution in Mexico City to determine the association of viral load (VL) and CD4+ lymphocyte kinetics with the development of oral candidosis (OC) and hairy leukoplakia (HL). Participants were HIV-infected adult subjects, without a history of or current OC or HL, not receiving HAART. Oral examinations were performed at baseline and every month for evidence of OC or HL; CD4+ and VL determinations were done at baseline, at 6-month intervals, when oral lesions were detected, and 2 months later. Affected subjects (OL group) by OC or HL had clinical intervals defined before (antecedent), during (concurrent), and after their development. In the nonaffected individuals (NA group), 6-month intervals were determined. Differences (changes) along the clinical and study intervals were calculated for CD4+ and VL. The median study time was 178 (range: 31-924) days; 99 patients were included. The 2-year cumulative incidence of either oral lesion was 54% (49.5% for OC and 33.2% for HL). In the OL group (31 patients) a progressive and continuous decrease of CD4+ was found in the antecedent interval followed by a significant increase in VL in the concurrent period. The NA group showed a significant fall in CD4+ by semester 3, without a significant rise of VL in the following semester. The effect of CD4+ remained significant in a multivariate analysis. This study has shown that the onset of OC and/or HL is heralded by the sequence of a sustained reduction of CD4+, followed by a sharp increase of VL. In the multivariate analysis, the decrease in CD4+ lymphocytes appeared to be the predominant factor predicting the appearance of these oral lesions. Their potential use as markers of a recent change in the immunologic and virologic status of HIV-infected individuals is emphasized.

Intermittent episodes of detectable HIV viremia in patients receiving nonnucleoside reverse-transcriptase inhibitor-based or protease inhibitor-based highly active antiretroviral therapy regimens are equivalent in incidence and prognosis

BACKGROUND

Intermittent episodes of detectable human immunodeficiency virus (HIV) viremia (hereafter referred to as "blips") are generally not predictive of subsequent virologic failure. Limited data are available for patients treated with nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based regimens.

METHODS

A retrospective cohort study evaluated patients receiving highly active antiretroviral therapy who were followed for > or =12 months, achieved an HIV RNA load of <50 copies/mL, and underwent evaluation every 2-3 months. A blip was defined as 1 HIV RNA load measurement of 50-1000 copies/mL that was preceded and followed by another HIV RNA load measurement of <50 copies/mL. The frequency and predictors of blips and virologic failure were studied.

RESULTS

There were 244 patients in the NNRTI group and 136 patients in the protease inhibitor (PI) group. Baseline characteristics between the 2 groups were similar. A total of 34% of patients in the NNRTI group and 33% in the PI group experienced viral blips (P=.855), with corresponding incidences of 19.2 and 19.7 blips, respectively, per 100 person-years. Median time to blips was 50.0 months after initiation of therapy in the NNRTI group (95% confidence interval [CI], 44.8-55.3 months) and 43.6 months in the PI group (95% CI, 33.7-53.6 months; P=.632, by the log-rank test). By Cox proportional hazards model analysis, only a history of antiretroviral therapy use (hazard ratio [HR], 2.01; P<.001) and a CD4 cell count of <200 cells/ mu L (HR, 1.70; P=.021) increased the risk for having a blip. During a median follow-up period of 23.5 months, 7.8% of patients in the NNRTI group and 8.1% in the PI group experienced virologic failure (P=.917). Cox proportional hazards model analysis showed that only a baseline CD4 cell count of <200 cells/ mu L predicted virologic failure (HR, 2.74; P=.032).

CONCLUSIONS

There is no difference in the frequency or prognostic significance of viral blips between patients receiving NNRTI-based therapy and patients receiving PI-based therapy. Our results suggest that viral blips occur at a similar rate among patients receiving NNRTI-based regimens and patients receiving PI-based regimens and that they are not predictive of virologic failure.

Advances in laboratory testing for HIV

In 2004, the diagnosis of established human immunodeficiency virus (HIV) infection can be made with close to 100% assurity. The extraordinarily engineered performances of HIV-screening assays are unprecedented. The well-established confirmatory tests performed by well-versed laboratories using criteria that are well understood in order to interpret the results of these tests give highly accurate outcomes of diagnostic testing strategies. Furthermore, the ability to monitor the progress of the infection and the viral pathogenesis is possible through the use of tests that quantify viral load or the peripheral CD4+ T-cells and other lymphocyte sub-type levels. Newer laboratory testing mechanisms, such as assessment of reverse transcriptase activity and sophisticated cell staining and flow cytometric analyses, have been used to map disease processes and progress on a research level and may be used in future to fine-tune therapy and to follow disease progression in even greater detail. Regulation of all HIV tests is of the highest level in Australia. In-house tests will be expected to conform to the levels specified for commercially produced tests.

Determinants of long-term highly active antiretroviral treatment efficacy

OBJECTIVES

Predictors of the efficacy of highly active antiretroviral therapy (HAART) have been investigated in several studies. To increase current knowledge, the study aimed to acquire comprehensive data over an extended observation time, to obtain information on possible performance differences among individual drugs, and to identify factors with influence on the initial response to a HAART regimen and the sustainability of the response.

METHODS

The data were obtained from a prospective, single University Medical School HIV cohort. Clinical, laboratory, and treatment parameters for 475 patients were collected over 4.5 years. HAART efficacy was determined by analysis of variance and multivariate survival analysis.

RESULTS

The overall initial complete response (CR) (<500 HIV-1 RNA copies/mL) was 76.3%. Use of indinavir [odds ratio (OR)=2.747, P=0.0009] and the number of new nucleoside reverse transcriptase inhibitors (NRTIs) (OR=1.862, P=0.0017) were positively associated with CR, while initial peripheral blood HIV RNA concentration (OR=0.383, P<0.0001), use of saquinavir hard gel capsules (OR=0.531, P=0.0302), the number of successive HAART regimens (OR=0.631, P<0.0001), and the number of previously used NRTIs (OR=0.728, P=0.0081) were negatively associated with CR. Sustainability of CR was positively correlated with use of indinavir [hazard ratio of relapse (HR)=0.255, P<0.0001] and haemoglobin levels (HR=0.873, P=0.0124), but negatively correlated with initial HIV RNA concentration (HR=1.273, P=0.0003) and the number of previously used NRTIs (HR=1.587, P<0.0001). A higher number of consecutive HAART regimens was associated with a markedly reduced CR, but with only a slightly higher risk of relapse.

CONCLUSIONS

The initial response to HAART, as well as long-term efficacy, depends strongly on a few fundamental parameters that can easily be assessed in a clinical setting. There is a need for effective suppression of HIV replication over decades, and these factors should be considered early in treatment planning to identify patients with an unfavourable profile of risk factors for treatment failure.

Markers of HIV-1 disease progression in individuals with haemophilia coinfected with hepatitis C virus: a longitudinal study

BACKGROUND

Low serum albumin concentration is associated with short-term survival in individuals with HIV-1. However, few investigators have assessed whether individuals with a low serum albumin concentration have delayed progression to AIDS, or survive in the long term. We aimed to assess the relation between markers of liver function and progression to AIDS and death in individuals with haemophilia infected with HIV-1 and hepatitis C virus.

METHODS

We measured markers of liver function and took CD4 counts every 3 months in 111 patients registered at the Royal Free Hospital Haemophilia Centre, London, UK. HIV RNA concentrations were measured yearly and then every 3-6 months from 1996. We used Cox's regression models to assess the independent prognostic value of these markers for AIDS and death.

FINDINGS

As a fixed covariate, albumin concentrations measured shortly after HIV-1 seroconversion were associated with risk of AIDS (relative hazard 0.91 [95% CI 0.84-1.00], p=0.04) and death (0.89 [0.82-0.96], p=0.004) over a 15-year period. These findings were independent of the CD4 count and HIV-1 RNA concentration. As a time-updated covariate, after adjustment for CD4 count and HIV-1 RNA concentrations, albumin was not associated with progression to AIDS (0.96 [0.90-1.01], p=0.13), but was strongly associated with death (0.88 [0.84-0.93], p<0.0001) in the short term.

INTERPRETATION

Low concentrations of albumin in individuals infected with HIV-1 could indicate a poor outlook and should therefore prompt concern at any stage of infection.

Therapeutic responses to AZT + 3TC + EFV in advanced antiretroviral naive HIV type 1-infected Ugandan patients

Convenient, non-food-dependent dosing, low tablet volume, and relatively low cost have made nonnucleoside reverse transcriptase inhibitors a first choice for both clinicians and patients in Uganda. Concerns exist as to their efficacy in patients with viral loads (VL) above 100,000 copies/ml, a feature common to about 75% of HIV-1-infected patients presenting at the Joint Clinical Research Center (JCRC) in Uganda. Furthermore, there are few data on the response to such therapy of non-B subtypes, A and D, predominant in Uganda. Presented here is a retrospective analysis of therapeutic responses in 11 antiretroviral (ARV) naïve HIV-1-infected Ugandan patients who had been initiated on zidovudine (AZT), lamivudine (3TC), and efavirenz (EFV). Laboratory assessments subsequent to initiation of ARV therapy, done at 11.6 +/- 3.9 weeks and 30.6 +/- 5.9 weeks, showed 88.9 and 71.4% patients achieved undetectable viral load, respectively. Virological suppression to below detection occurred in 85.7% of patients at 11.6 weeks despite baseline VL >or= 100,000 copies/ml. At 31 weeks there was a median increment of +183 cells/mm(3) in CD4(+) T lymphocytes. These findings reflect significant efficacy in the use of AZT + 3TC + EFV in advanced ARV naive non-B subtype HIV-1-infected patients. The therapeutic responses were comparable to those previously described in the western world.

Low level viremia and high CD4% predict normal survival in a cohort of HIV type-2-infected villagers

A community-based study of human immunodeficiency virus type 2 (HIV-2) infection was conducted in a rural village in northern Guinea Bissau, West Africa to assess the relationship between plasma HIV-2 RNA levels, CD4 lymphocyte percentage, and survival over an 8-year period. The cohort of 133 HIV-2-infected individuals and 160 HIV-uninfected controls enrolled in 1991 were followed up at home until 1998. Thirty-one (23%) HIV-2-infected and 24 (16%) HIV-uninfected individuals died over the follow-up period (mortality hazard ratio 1.7, 95% CI 1.0, 2.9; p= 0.06). In HIV-2-infected individuals, the median HIV-2 RNA level was 347 copies/ml and the mean CD4% was 28.6. Both plasma viremia and CD4% were independent predictors of survival, with hazard ratios increasing by 1.6 (95% CI, 1.1, 2.3) for each log(10) increase of plasma viremia and 1.7 (1.1, 2.6) for each 10% decrease of CD4%. Infected subjects with a plasma viral load >or= the median (347 copies/ml) and a CD4% <or= the mean (28.6%) had a mortality hazard ratio of 3.1 (95% CI 1.7, 5.8) compared to uninfected controls, whereas the remaining infected subjects had a mortality rate similar to uninfected controls, the mortality hazard ratio being 1.0 (95% CI, 0.5, 2.1.) In those who survived between 1991 and 1996, HIV-2 RNA levels were unchanged overall and CD4 lymphocyte counts remained high. In conclusion, baseline HIV-2 RNA levels predicted a normal survival for the majority, with low and stable levels of plasma viremia characterizing HIV-2 infections in this rural West African community.

Goals and milestones during treatment of HIV-1 infection with antiretroviral therapy: a pathogenesis-based perspective

Highly active antiretroviral therapy (HAART) has reduced the morbidity and mortality related to infection with the human immunodeficiency virus-1 (HIV-1) through its ability to suppress viral replication and preserve and reconstitute specific immune responses in many infected individuals. However, the complete eradication of HIV-1 with current HAART regimens is not considered possible by most experts. Moreover, many current antivirals have metabolic complications and limiting side effects. Consequently, the treatment paradigm has shifted from 'hit hard and early' to delaying the initiation of therapy until later in the course of HIV-1-related disease, with corresponding modifications of consensus treatment guidelines. Factors that need to be considered in deciding when to initiate therapy and with what regimen include the patient's risk of disease progression, the possible adverse drug effects, the patient's ability to adhere to the prescribed therapy, and the need to preserve future therapeutic options. In this article, we discuss the issues surrounding the initiation of HAART, and describe the virologic and immunologic milestones that may be achieved with effective antiretroviral therapy.

Predictive value of HIV-1 viral load on risk for opportunistic infection

OBJECTIVE

The relationship between HIV-1 viral load and the risk for opportunistic infection (OI) was examined in Adult AIDS Clinical Trial Group (AACTG) 722, a virology substudy of AACTG 323: a phase 4 randomized study designed to examine the use of chronic suppressive versus episodic fluconazole therapy.

METHODS

The primary analysis used a case-control sampling scheme with two controls per "case" (subjects that developed an OI) matched by gender, age, and time on study. Forty-five cases and matched controls were identified and used in the analysis.

RESULTS

Study 722 accrued 518 subjects between 5/97 and 11/99. Forty-five subjects developed serious OIs or refractory candidiasis. Median baseline CD4 count was 24 cell/mm3 for cases and 46 for controls (p =.003). Median viral load (VL) was 5.02 log10 copies/mL for cases and 4.08 for controls (p =.002). Multivariate analysis found four independent variables associated with time to OI: baseline VL and CD4 (RR = 2.2 per log increment and 6.0 per 50-cell increment, respectively), a one log increase in VL at any time (RR = 15), and history of an OI (RR = 5.2).

CONCLUSIONS

VL and changes in VL were independently associated with risk of development of OIs in a prospective study and should be considered by clinicians when assessing patients for risk of OI.

A randomized study of the utility of human immunodeficiency virus RNA measurement for the management of antiretroviral therapy

To compare frequent measurement with infrequent measurement of human immunodeficiency virus (HIV) RNA levels in the management of antiretroviral therapy, we conducted a clinical strategy study of 206 HIV-infected patients who had <500 CD4 cells/mm(3). Patients were randomized (1.5:1) to undergo frequent monitoring (at baseline and every 2 months) or infrequent monitoring (at baseline and twice yearly), with CD4 cell counts determined every 2 months. Patients received unrestricted antiretroviral therapy. In the primary analysis (at month 6), the frequent group had a mean HIV RNA reduction (+/- standard deviation) of 0.93+/-0.79 log(10) copies/mL, versus 0.48+/-0.83 log(10) copies/mL for the infrequent group (P=.0002). A trend (P=.1) toward improved survival was seen in the frequent group. Given this improved virological response, more frequent HIV RNA measurement than is recommended in published guidelines (every 3-4 months) may be appropriate.

Decreased recovery of CD4 lymphocytes in older HIV-infected patients beginning highly active antiretroviral therapy

Among virological responders, the area under the curve of the CD4 count minus baseline (AUCMB) after 3, 9, 15 and 18 months of highly active antiretroviral therapy (HAART) was less in individuals 55 years or older (P < 0.05). Fewer older individuals achieved increases of 50, 100, or over 150 CD4 cells/l. A random quadratic time course model estimated that the AUCMB decreased 35 cells/year for each 10 years of additional age during the first 12 months after HAART (P < 0.005).

Initial virological and immunologic response to highly active antiretroviral therapy predicts long-term clinical outcome

Little is known about the long-term clinical outcomes for human immunodeficiency virus (HIV)-infected patients who have received highly active antiretroviral therapy (HAART). Determining factors associated with long-term clinical outcomes early in the course of treatment may allow modifications to be made for patients who are at a greater risk of treatment failure. To evaluate these factors, we studied 213 HIV-infected patients who had received HAART for at least 115 weeks. In the univariate analysis, virological response, which was measured as the change in virus load from baseline at month 3 of treatment, was the single best predictor of clinical outcome (relative hazard, 0.722; P=.001), independent of virological suppression. In the multivariate analysis, virological response and immunologic response, which was measured as an increase in CD4 cell count of >200 cells/mm(3), resulted in better prediction of clinical outcomes than did use of either variable alone (P=.02). Our results indicate that changes in virus load and immunologic response together are good predictors of clinical outcome and can be assessed after the initiation of HAART, which would allow clinicians to identify patients early in the course of therapy who are at greater risk of negative outcome.

Elevated plasma stromal cell-derived factor 1 protein level in the progression of HIV type 1 infection/AIDS

Stromal cell-derived factor 1 (SDF-1) is a unique chemokine involved in multiple organogenesis as well as in the regulation of HIV infection. Here we determined the plasma SDF-1 concentrations of 193 HIV-1-infected individuals and 154 normal Japanese volunteers by developing a highly sensitive measurement system based on time-resolved fluoroimmunoassay (SDF-1 TR-FIA). This system is also valid for the mouse model to quantitate circulating SDF-1 concentration in vivo and thereby its correlation with CXCR4 expression level on CD4(+) T cells. Interestingly, plasma SDF-1 concentrations in HIV-1-infected individuals were three times higher than those in a normal control group and plasma SDF-1 protein levels showed an inverse correlation with CD4(+) T cell count and a positive correlation with plasma HIV-1 RNA load. Notably, individuals with later stage HIV-1 infection, who maintained fewer than 200 CD4(+) T cells per cubic milliliter and more than 10,000 copies of HIV-1 RNA per milliliter, showed the highest plasma SDF-1 level among individuals at any stage of HIV-1 infection. These results suggest that endogenous SDF-1 is upregulated by HIV-1 infection, particularly in late-stage HIV-1 infection/AIDS.

Human immunodeficiency virus type 1 RNA level and CD4 count as prognostic markers and surrogate end points: a meta-analysis. HIV Surrogate Marker Collaborative Group

OBJECTIVE

To evaluate treatment-mediated changes in HIV-1 RNA and CD4 count as prognostic markers and surrogate end points for disease progression (AIDS/death).

METHODS

Data from 13,045 subjects in all 16 randomized trials comparing nucleoside analogue reverse transcriptase inhibitors and having HIV-1 RNA measurements at 24 weeks were obtained. A total of 3146 subjects had HIV-1 RNA and CD4 count determinations at 24 weeks after starting treatment.

RESULTS

At Week 24, the percentage of subjects experiencing an HIV-1 RNA decrease of >1 log10 copies/ml or a CD4 count increase of >33% was similar (22% vs. 25%). Changes in both markers at Week 24 were significant independent predictors of AIDS/death: across trials, the average reduction in hazard was 51% per 1 log10 HIV-1 RNA copies/ml decrease (95% confidence interval: 41%, 59%) and 20% per 33% CD4 count increase (17%, 24%). In univariate analyses, the hazard ratio for AIDS/death in randomized treatment comparisons was significantly associated with differences between treatments in mean area under the curve of HIV-1 RNA changes to Weeks 8 and 24 (AUCMB) and mean CD4 change at Week 24, but, in multivariate analysis, only mean CD4 change was significant.

CONCLUSIONS

Change in HIV-1 RNA, particularly using AUCMB, and in CD4 count should be measured to aid patient management and evaluation of treatment activity in clinical trials. However, short-term changes in these markers are imperfect as surrogate end points for long-term clinical outcome because two randomized treatment comparisons may show similar differences between treatments in marker changes but not similar differences in progression to AIDS/death.