Virologic, immunologic, and immune activation markers as predictors of HIV-associated weight loss prior to AIDS. Multicenter AIDS Cohort Study

Metabolomics as a Tool to Investigate HIV/TB Co-Infection

The HIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome) and tuberculosis (TB) pandemics are perpetuated by a significant global burden of HIV/TB co-infection. The synergy between HIV and Mycobacterium tuberculosis (Mtb) during co-infection of a host is well established. While this synergy is known to be driven by immunological deterioration, the metabolic mechanisms thereof remain poorly understood. Metabolomics has been applied to study various aspects of HIV and Mtb infection separately, yielding insights into infection- and treatment-induced metabolic adaptations experienced by the host. Despite the contributions that metabolomics has made to the field, this approach has not yet been systematically applied to characterize the HIV/TB co-infected state. Considering that limited HIV/TB co-infection metabolomics studies have been published to date, this review briefly summarizes what is known regarding the HIV/TB co-infection synergism from a conventional and metabolomics perspective. It then explores metabolomics as a tool for the improved characterization of HIV/TB co-infection in the context of previously published human-related HIV infection and TB investigations, respectively as well as for addressing the gaps in existing knowledge based on the similarities and deviating trends reported in these HIV infection and TB studies.

Evolving character of chronic central nervous system HIV infection

Human immunodeficiency virus type 1 (HIV-1) infection of the central nervous system (CNS) begins early in systemic infection and continues throughout its untreated course. Despite a common cerebrospinal fluid inflammatory response, it is usually neurologically asymptomatic for much of this course, but can evolve in some individuals to HIV-associated dementia (HAD), a severe encephalopathy with characteristic cognitive and motor dysfunction. While widespread use of combination antiretroviral therapy (ART) has led to a marked decline in both the CNS infection and its neurologic severe consequence, HAD continues to afflict individuals presenting with advanced systemic infection in the developed world and a larger number in resource-poor settings where ART is more restricted. Additionally, milder CNS injury and dysfunction have broader prevalence, including in those treated with ART. Here we review the history and evolving nomenclature of HAD, its viral pathogenesis, clinical presentation and diagnosis, and treatment.

Approach to cerebrospinal fluid (CSF) biomarker discovery and evaluation in HIV infection

Central nervous system (CNS) infection is a nearly universal facet of systemic HIV infection that varies in character and neurological consequences. While clinical staging and neuropsychological test performance have been helpful in evaluating patients, cerebrospinal fluid (CSF) biomarkers present a valuable and objective approach to more accurate diagnosis, assessment of treatment effects and understanding of evolving pathobiology. We review some lessons from our recent experience with CSF biomarker studies. We have used two approaches to biomarker analysis: targeted, hypothesis-driven and non-targeted exploratory discovery methods. We illustrate the first with data from a cross-sectional study of defined subject groups across the spectrum of systemic and CNS disease progression and the second with a longitudinal study of the CSF proteome in subjects initiating antiretroviral treatment. Both approaches can be useful and, indeed, complementary. The first is helpful in assessing known or hypothesized biomarkers while the second can identify novel biomarkers and point to broad interactions in pathogenesis. Common to both is the need for well-defined samples and subjects that span a spectrum of biological activity and biomarker concentrations. Previously-defined guide biomarkers of CNS infection, inflammation and neural injury are useful in categorizing samples for analysis and providing critical biological context for biomarker discovery studies. CSF biomarkers represent an underutilized but valuable approach to understanding the interactions of HIV and the CNS and to more objective diagnosis and assessment of disease activity. Both hypothesis-based and discovery methods can be useful in advancing the definition and use of these biomarkers.

HIV Wasting Syndrome in a Nigerian Failing Antiretroviral Therapy: A Case Report and Review of the Literature

The HIV wasting syndrome represented the face of HIV/AIDS before the advent of highly active antiretroviral therapy (HAART). Although the incidence of wasting has declined since the introduction of HAART, weight loss remains common in patients receiving HAART, especially in the setting of a failing HAART regimen. As we are not aware of any previous reports from Nigeria, we report a case of the classical wasting syndrome in a Nigerian female who had both virological and immunological HAART failure due to poor adherence. The influence of a failing HAART regimen, socioeconomic status, and other clinical variables in the wasting syndrome are discussed.

Nutrition issues in the HIV-infected injection drug user: findings from the nutrition for healthy living cohort

OBJECTIVE

The purpose of this paper is to highlight disparities between injection drug users (IDUs) and those who had never been IDUs from the Nutrition for Healthy Living (NFHL) cohort. Although IDUs were enrolled in the cohort throughout its duration, few analyses have sought to highlight findings specific to them.

METHODS

NFHL, a prospective, longitudinal cohort conducted from 1995-2005, included 881 human immunodeficiency virus (HIV) -infected men and women over the age of 18. Subjects were seen every 6 months; body composition and dietary and laboratory data were collected. Individuals were classified as current IDUs, past IDUs, and never-IDUs. The classification of ever-IDU combined current and past users.

RESULTS

In NFHL, a higher proportion of ever-IDUs were women, African American, had a high school education or less, smoked, and were housing insecure and food insecure compared to never-IDUs. Ever-IDUs had lower total, soluble, and insoluble fiber and individual micronutrient intakes. A higher proportion of ever-IDUs had hepatitis C and HIV-related symptoms, used highly active antiretroviral therapy (HAART) less, and had a CD4 count <500 cells/mm3, than never-IDUs, at the study endpoint.

CONCLUSIONS

The course of HIV infection in past and current IDUs appears to be unique and requires more investigation. Physiologic and sociodemographic characteristics of IDUs contribute to poor disease management and nutritional status. Classic manifestations of HIV persist in IDUs in the HAART era.

Psychiatric and neurophysiological predictors of obesity in HIV/AIDS

The objective of the study was to identify predictors of obesity. One hundred eleven nonobese and 48 obese HIV-1 seropositive patients provided information on medical history and other characteristics. They were then asked to detect the passage of 2-s time intervals while the contingent negative variation (CNV) was recorded. Obese patients were healthier, more likely to be receiving Highly Active Antiretroviral Therapy, and less likely to be substance dependent. Obese patients also exhibited a greater CNV slope and responded prematurely. A path model suggested that CD4+count and protease inhibitor use directly predicted obesity. Depression had no direct effect. However, when incorporated into a hypothetical construct, "mood dysregulation," that also included childhood conduct problems and stimulant dependence, the shared variance among the indicators did predict obesity. This relationship was mediated through premature response preparation (anterior scalp CNV amplitude) and its hypothesized association with impatience/impulsivity.

HIV-Related Wasting in HIV-Infected Drug Users in the Era of Highly Active Antiretroviral Therapy

BACKGROUND

A decrease in the rate of human immunodeficiency virus (HIV) infection-related wasting has been reported in the era of highly active antiretroviral therapy (HAART). We investigated this concern in a hard-to-reach population of HIV-infected drug users in Miami, Florida.

METHODS

After informed consent was obtained, 119 HIV-infected drug users were administered questionnaires involving demographic, medical history, and food-security information. Blood samples were drawn for immunological and viral studies. HIV-related wasting over a period of > or =6 months was defined as a body mass index of <18.5 kg/m2, unintentional weight loss of > or =10% over 6 months, or a weight of <90% of the ideal body weight.

RESULTS

The prevalence of HIV-related wasting was 17.6%. A significantly higher proportion of those who experienced wasting (81%) reported that there were periods during the previous month when they went for > or =1 day without eating (i.e., food insecurity), compared with those who did not experience wasting (57%). Although a greater percentage of patients who experienced wasting were receiving HAART, their HIV RNA levels were more than twice as high (mean+/-standard deviation [SD], 166,689+/-238,002 copies/mL; median log HIV RNA level +/- SD, 10.2+/-2.7 log10 copies/mL) as those for the group that did not experience wasting (mean+/-SD, 72,156 +/- 149,080; median log HIV RNA level+/-SD, 9.2+/-2.3 log10 copies/mL). Participants who experienced wasting were more likely to be heavy alcohol drinkers and users of cocaine. In multivariate analysis that included age, sex, food security, alcohol use, cocaine use, viral load, and receipt of antiretroviral therapy, the only significant predictors of wasting were > or =1 day without eating during the previous month (odds ratio [OR], 1.96; 95% confidence interval [CI], 1.18-3.26; P=.01) and viral load (OR, 1.64; 95% CI, 1.00-2.69; P=.05).

CONCLUSIONS

HIV-related wasting continues to be common among HIV-infected drug users, even among HAART recipients. Food insecurity and viral load were the only independent predictors of wasting. The social and economic conditions affecting the lifestyle of HIV-infected drug users constitute a challenge for prevention and treatment of wasting.

Understanding the Role of HIV Load in Determining Weight Change in the Era of Highly Active Antiretroviral Therapy

BACKGROUND

In this prospective cohort study, we determined the relationship between human immunodeficiency virus (HIV) RNA load and body weight in patients with HIV infection.

METHODS

Repeated-measures analysis was restricted to patients with >or=2 study visits, 4-9-month intervals between study visits, and complete data on virus load, resting energy expenditure (REE), and highly active antiretroviral therapy (HAART). The outcome was change in body weight across study intervals. The main predictor was virus load. Separate analyses were performed for weight change in patients receiving and patients not receiving HAART.

RESULTS

The eligible sample consisted of 318 participants associated with 1886 study intervals. Sixty-one patients (19%) were women, and 173 (54%) were undergoing HAART at the time of enrollment. There was a significant interaction (P=.01) between virus load and HAART use. In the absence of HAART, each log(10) increase in virus load was associated with a 0.92-kg decrease in body weight (P=.003), but during HAART, virus load was not significantly associated with weight change. During HAART, a CD4(+) cell count decrease of 100 cells/mm(3), rather than a change in the virus load, was associated with a 0.35-kg decrease in body weight (P<.001). REE was independently associated with weight change in both models (P<.001).

CONCLUSIONS

Patients with HIV infection who are losing weight and are not taking HAART should be considered for HAART. Patients who are already receiving HAART and have unsuppressed virus loads may benefit virologically from an intensified regimen, because such a regimen may lead to complete suppression if there is an accompanying increase in CD4(+) cell counts. Further research is needed to understand the strong independent effect of changes in REE among patients receiving and patients not receiving HAART.