Publications

BACKGROUND/AIMS

Although HIV-infected persons are at higher risk for acute kidney injury (AKI) during hospitalization compared with their uninfected counterparts, risk factors for AKI are not well-defined. We aimed to describe the evolving incidence of AKI among HIV-infected individuals and to identify important AKI risk factors.

METHODS

We conducted a prospective cohort study of 56,823 HIV-infected persons in the Department of Veterans Affairs Clinical Case Registry. Outcomes were: AKI (acute in-hospital serum creatinine increase of ≥0.3 mg/dl, or a relative increase by 50% or greater), and dialysis-requiring AKI. We used proportional hazards regressions to identify risk factors.

RESULTS

From its peak in 1995 at 62 per 1,000 person-years, the incidence of AKI declined after the introduction of highly active antiretroviral therapy (HAART) in 1996 to a low point of 25 per 1,000 person-years in 2006. Incidence of dialysis-requiring AKI declined in the early 1990s, but doubled between 2000 and 2006. Using multivariate proportional hazard regression, we identified the following strong risk factors for AKI: chronic kidney disease (eGFR <60 ml/min/1.73 m(2)) (5.38, 95% CI: 5.11-5.67), proteinuria (1.78, 1.70-1.87), low serum albumin (<3.7 mg/dl) (5.24, 4.82-5.71), low body mass index (<18.5 kg/m(2)) (1.69, 1.54-1.86), cardiovascular disease (1.77, 1.66-1.89), low CD4 count (<200 cells/mm(3)) (2.54, 2.33-2.77), and high viral load (≥100,000 copies/ml) (2.51, 2.28-2.75). In addition, there was substantial heterogeneity in the strengths of risk factors for dialysis-requiring AKI before and after the introduction of HAART.

CONCLUSIONS

Although AKI incidence has decreased during the HAART era, it remains common in HIV-infected persons and appears attributable to both kidney- and HIV-related factors.

Because multiple symptoms associated with "sickness behavior" have a negative impact on functional status and quality of life, increased information on the mechanisms that underlie inter-individual variability in this symptom experience is needed. The purposes of this study were to determine: if distinct classes of individuals could be identified based on their experience with pain, fatigue, sleep disturbance, and depression; if these classes differed on demographic and clinical characteristics; and if variations in pro- and anti- inflammatory cytokine genes were associated with latent class membership. Self-report measures of pain, fatigue, sleep disturbance, and depression were completed by 168 oncology outpatients and 85 family caregivers (FCs). Using latent class profile analysis (LCPA), three relatively distinct classes were identified: those who reported low depression and low pain (83%), those who reported high depression and low pain (4.7%), and those who reported high levels of all four symptoms (12.3%). The minor allele of IL4 rs2243248 was associated with membership in the "All high" class along with younger age, being White, being a patient (versus a FC), having a lower functional status score, and having a higher number of comorbid conditions. Findings suggest that LPCA can be used to differentiate distinct phenotypes based on a symptom cluster associated with sickness behavior. Identification of distinct phenotypes provides new evidence for the role of IL4 in the modulation of a sickness behavior symptom cluster in oncology patients and their FCs.

This work presents a novel method for detecting nucleic acid targets using a ligation step along with an isothermal, exponential amplification step. We use an engineered ssDNA with two variable regions on the ends, allowing us to design the probe for optimal reaction kinetics and primer binding. This two-part probe is ligated by T4 DNA Ligase only when both parts bind adjacently to the target. The assay demonstrates that the expected 72-nt RNA product appears only when the synthetic target, T4 ligase, and both probe fragments are present during the ligation step. An extraneous 38-nt RNA product also appears due to linear amplification of unligated probe (P3), but its presence does not cause a false-positive result. In addition, 40 mmol/L KCl in the final amplification mix was found to be optimal. It was also found that increasing P5 in excess of P3 helped with ligation and reduced the extraneous 38-nt RNA product. The assay was also tested with a single nucleotide polymorphism target, changing one base at the ligation site. The assay was able to yield a negative signal despite only a single-base change. Finally, using P3 and P5 with longer binding sites results in increased overall sensitivity of the reaction, showing that increasing ligation efficiency can improve the assay overall. We believe that this method can be used effectively for a number of diagnostic assays.

Depression is common among people living with HIV/AIDS and contributes to a wide range of worsened HIV-related outcomes, including AIDS-related mortality. Targeting modifiable causes of depression, either through primary or secondary prevention, may reduce suffering as well as improve HIV-related outcomes. Food insecurity is a pervasive source of uncertainty for those living in resource-limited settings, and cross-sectional studies have increasingly recognized it as a critical determinant of poor mental health. Using cohort data from 456 men and women living with HIV/AIDS initiating HIV antiretroviral therapy in rural Uganda, we sought to (a) estimate the association between food insecurity and depression symptom severity, (b) assess the extent to which social support may serve as a buffer against the adverse effects of food insecurity, and (c) determine whether the buffering effects are specific to certain types of social support. Quarterly data were collected by structured interviews and blood draws. The primary outcome was depression symptom severity, measured by a modified Hopkins Symptom Checklist for Depression. The primary explanatory variables were food insecurity, measured with the Household Food Insecurity Access Scale, and social support, measured with a modified version of the Functional Social Support Questionnaire. We found that food insecurity was associated with depression symptom severity among women but not men, and that social support buffered the impacts of food insecurity on depression. We also found that instrumental support had a greater buffering influence than emotional social support. Interventions aimed at improving food security and strengthening instrumental social support may have synergistic beneficial effects on both mental health and HIV outcomes among PLWHA in resource-limited settings.

BACKGROUND

Individuals infected with human immunodeficiency virus (HIV) have higher risk than HIV-negative individuals for diseases associated with aging. T-cell senescence, characterized by expansion of cells lacking the costimulatory molecule CD28, has been hypothesized to mediate these risks.

METHODS

We measured the percentage of CD28(-)CD4(+) and CD8(+) T cells from HIV-infected treatment-naive adults from 5 Adult Clinical Trials Group (ACTG) antiretroviral therapy (ART) studies and the ALLRT (ACTG Longitudinal Linked Randomized Trials) cohort, and from 48 HIV-negative adults. Pretreatment and 96-week posttreatment %CD28(-) cells were assessed using linear regression for associations with age, sex, race/ethnicity, CD4 count, HIV RNA, ART regimen, and hepatitis C virus (HCV) infection.

RESULTS

In total, 1291 chronically HIV-infected adults were studied. Pretreatment, lower CD4 count was associated with higher %CD28(-)CD4(+) and %CD28(-)CD8(+) cells. For CD8(+) cells, younger age and HCV infection were associated with a lower %CD28(-). ART reduced %CD28(-) levels at week 96 among virally suppressed individuals. Older age was strongly predictive of higher %CD28(-)CD8(+). Compared to HIV-uninfected individuals, HIV-infected individuals maintained significantly higher %CD28(-).

CONCLUSIONS

Effective ART reduced the proportion of CD28(-) T cells. However, levels remained abnormally high and closer to levels in older HIV-uninfected individuals. This finding may inform future research of increased rates of age-associated disease in HIV-infected adults.