Dysregulation of Systemic and Mucosal Humoral Responses to Microbial and Food Antigens as a Factor Contributing to Microbial Translocation and Chronic Inflammation in HIV-1 Infection.

HIV-1 infection is associated with an early and profound depletion of mucosal memory CD4+ T cells, a population that plays an indispensable role in the regulation of isotype switching and transepithelial transport of antibodies. In this study, we addressed whether the depletion of CD4+ T cell in HIV-1-infected individuals results in altered humoral responses specific to antigens encountered at mucosal surfaces. Comprehensive protein microarray of systemic humoral responses to intestinal microbiota demonstrated reduced IgG responses to antigens derived from Proteobacteria and Firmicutes but not Bacteroidetes. Importantly, intestinal secretions of antiretroviral therapy-treated HIV-1-infected individuals exhibited a significant elevation of IgM levels and decreased IgA/IgM and IgG/IgM ratios of antibodies specific to a variety of microbial and food antigens. The presented findings indicate reduced competence of mucosal B cells for class switch recombination from IgM to other isotypes limiting their capacity to react to changing antigenic variety in the gut lumen. Decreased availability of microbiota-specific IgA and IgG may be an important factor contributing to the translocation of microbial antigens across the intestinal mucosal barrier and their systemic dissemination that drives chronic inflammation in HIV-1-infected individuals.

Incidence and Predictors of Abnormal Anal Cytology Findings Among HIV-Infected Adults Receiving Contemporary Antiretroviral Therapy.

BACKGROUND: Anal cancer rates are higher for human immunodeficiency virus (HIV)-infected adults than for uninfected adults. Limited published data exist characterizing the incidence of precursor lesions detected by anal cytology. METHODS: The Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy was a prospective cohort of 700 HIV-infected participants in 4 US cities. At baseline and annually thereafter, each participant completed a behavioral questionnaire, and healthcare professionals collected anorectal swabs for cytologic examination and human papillomavirus (HPV) detection and genotyping. RESULTS: Among 243 participants with negative baseline results of anal cytology, 37% developed abnormal cytology findings (incidence rate, 13.9 cases/100 person-years of follow-up; 95% confidence interval [CI], 11.3-16.9) over a median follow-up duration of 2.1 years. Rates among men having sex with men, among women, and among men having sex with women were 17.9 cases/person-years of follow-up (95% CI, 13.9-22.7), 9.4 cases/person-years of follow-up (95% CI, 5.6-14.9), and 8.9 cases/person-years of follow-up (95% CI, 4.8-15.6), respectively. In multivariable analysis, the number of persistent high-risk HPV types (adjusted hazard ratio [aHR], 1.17; 95% CI, 1.01-1.36), persistent high-risk HPV types except 16 or 18 (aHR, 2.46; 95% CI, 1.31-4.60), and persistent types 16 or 18 (aHR, 3.90; 95% CI, 1.78-8.54) remained associated with incident abnormalities. CONCLUSIONS: The incidence of abnormal anal cytology findings was high and more likely to develop among persons with persistent high-risk HPV.

Inhibition of the lymphocyte metabolic switch by the oxidative burst of human neutrophils.

Activation of the phagocytic NADPH oxidase-2 (NOX-2) in neutrophils is a critical process in the innate immune system and is associated with elevated local concentrations of superoxide, hydrogen peroxide (H2O2) and hypochlorous acid. Under pathological conditions, NOX-2 activity has been implicated in the development of autoimmunity, indicating a role in modulating lymphocyte effector function. Notably, T-cell clonal expansion and subsequent cytokine production requires a metabolic switch from mitochondrial respiration to aerobic glycolysis. Previous studies demonstrate that H2O2 generated from activated neutrophils suppresses lymphocyte activation but the mechanism is unknown. We hypothesized that activated neutrophils would prevent the metabolic switch and suppress the effector functions of T-cells through a H2O2-dependent mechanism. To test this, we developed a model co-culture system using freshly isolated neutrophils and lymphocytes from healthy human donors. Extracellular flux analysis was used to assess mitochondrial and glycolytic activity and FACS analysis to assess immune function. The neutrophil oxidative burst significantly inhibited the induction of lymphocyte aerobic glycolysis, caused inhibition of oxidative phosphorylation and suppressed lymphocyte activation through a H2O2-dependent mechanism. Hydrogen peroxide and a redox cycling agent, DMNQ, were used to confirm the impact of H2O2 on lymphocyte bioenergetics. In summary, we have shown that the lymphocyte metabolic switch from mitochondrial respiration to glycolysis is prevented by the oxidative burst of neutrophils. This direct inhibition of the metabolic switch is then a likely mechanism underlying the neutrophil-dependent suppression of T-cell effector function.

Mechanisms Influencing Circadian Blood Pressure Patterns Among Individuals with HIV.

HIV+ individuals have an increased risk for cardiovascular disease (CVD), but the mechanisms behind this association are poorly understood. While hypertension is a well-established CVD risk factor, clinic-based blood pressure (BP) assessment by itself cannot identify several important BP patterns, including white coat hypertension, masked hypertension, nighttime hypertension, and nighttime BP dipping. These BP patterns can be identified over a 24-h period by ambulatory BP monitoring (ABPM). In this review, we provide an overview of the potential value of conducting ABPM in HIV+ individuals. ABPM phenotypes associated with increased CVD risk include masked hypertension (i.e., elevated out-of-clinic BP despite non-elevated clinic BP), nighttime hypertension, and a non-dipping BP pattern (i.e., a drop in BP of <10 % from daytime to nighttime). These adverse ABPM phenotypes may be highly relevant in the setting of HIV infection, given that increased levels of inflammatory biomarkers, high psychosocial burden, high prevalence of sleep disturbance, and autonomic dysfunction have been commonly reported in HIV+ persons. Additionally, although antiretroviral therapy (ART) is associated with lower AIDS-related morbidity and CVD risk, the mitochondrial toxicity, oxidative stress, lipodystrophy, and insulin resistance associated with long-term ART use potentially lead to adverse ABPM phenotypes. Existing data on ABPM phenotypes in the setting of HIV are limited, but suggest an increased prevalence of a non-dipping BP pattern. In conclusion, identifying ABPM phenotypes may provide crucial information regarding the mechanisms underlying the excess CVD risk in HIV+ individuals.

Current practices of screening for incident hepatitis C virus (HCV) infection among HIV-infected, HCV-uninfected individuals in primary care.

BACKGROUND: Human immunodeficiency virus (HIV)-infected, hepatitis C virus (HCV)-uninfected patients are at risk for incident HCV infection, but little is known about screening practices for incident HCV among HIV-infected individuals in HIV primary care clinics. METHODS: We used data from the Center for AIDS Research Network of Integrated Clinical Systems (CNICS) to investigate historical trends in screening for incident HCV infection among HIV-infected patients who were HCV-uninfected at enrollment in care. We used descriptive measures and Poisson regression to identify factors associated with screening for HCV infection (using HCV antibody or RNA), performed temporal analyses to assess changes in screening over time, and investigated the frequency with which elevated alanine aminotransferase (ALT) levels were followed by diagnostic HCV testing. RESULTS: Among 17 090 patients registered at CNICS sites between 2000 and 2011, 14 534 (85%) received HCV antibody screening within 3 months of enrolling in care, and 9077 met all of the inclusion criteria. Only 55.6% ever received additional HCV screening. HCV screening increased over time, but not uniformly at all sites. Only 26.7% of first-time ALT elevations to >100 IU/L were followed up within 12 months by HCV antibody or RNA testing. CONCLUSIONS: Although most HIV-infected patients were screened for prevalent HCV infection at enrollment in care, only half who were HCV uninfected were screened again. Screening varied between sites, even when controlling for demographics and risk behaviors. Patients with new ALT elevations to >100 IU/L were seldom assessed for incident HCV infection. Guidelines are needed to help HIV providers know whom to screen, how frequently to screen, and which screening test to use.

Metabolic consequences of HIV: pathogenic insights.

With the advances in antiretroviral therapy (ART), HIV infection has been transformed into a chronic medical condition that can be effectively managed like diabetes or hypertension. For HIV care providers, the focus of care for many patients has shifted from prevention of opportunistic infection and AIDS-related conditions to age-related cardiometabolic comorbidities, including cardiovascular disease, diabetes, obesity, and frailty. Numerous reports have highlighted that these diseases are occurring at an earlier age among HIV-infected persons. However, there is an ongoing debate regarding the role of HIV infection, ART, and other factors that may underlie the accelerated occurrence of these diseases. Herein, we review the epidemiology of the US HIV epidemic with regards to several metabolic comorbidities and address mechanisms that likely contribute to the current nature of HIV disease.

Bone alterations associated with HIV.

HIV infection and initiation of antiretroviral therapy (ART) have been consistently associated with decreased bone mineral density (BMD), with growing evidence linking HIV to an increased risk of fracture. This is especially concerning with the expanding number of older persons living with HIV. Interestingly, recent data suggest that HIV-infected children and youth fail to achieve peak BMD, possibly increasing their lifetime risk of fracture. Elucidating the causes of the bone changes in HIV-positive persons is challenging because of the multifactorial nature of bone disease in HIV, including contribution of the virus, immunosuppression, ART toxicity, and traditional osteoporosis risk factors, such as age, lower weight, tobacco, and alcohol use. Thus, practitioners must recognize the risk of low BMD and fractures and appropriately screen patients for osteoporosis if risk factors exist. If fractures do occur or elevated fracture risk is detected through screening, treatment with bisphosphonate medications appears safe and effective in the HIV+population.

Improving cervical cancer screening rates in an urban HIV clinic.

Human immunodeficiency virus (HIV)-infected women are at increased risk of invasive cervical cancer; however, screening rates remain low. The objectives of this study were to analyze a quality improvement intervention to increase cervical cancer screening rates in an urban academic HIV clinic and to identify factors associated with inadequate screening. Barriers to screening were identified by a multidisciplinary quality improvement committee at the Washington University Infectious Diseases clinic. Several strategies were developed to address these barriers. The years pre- and post-implementation were analyzed to examine the clinical impact of the intervention. A total of 422 women were seen in both the pre-implementation and post-implementation periods. In the pre-implementation period, 222 women (53%) underwent cervical cancer screening in the form of Papanicolaou (Pap) testing. In the post-implementation period, 318 women (75.3%) underwent cervical cancer screening (p < 0.01). Factors associated with lack of screening included fewer visits attended (pre: 4.2 ± 1.5; post: 3.4 ± 1.4; p < 0.01). A multidisciplinary quality improvement intervention was successful in overcoming barriers and increasing cervical cancer screening rates in an urban academic HIV clinic.

Pilot study of pioglitazone and exercise training effects on basal myocardial substrate metabolism and left ventricular function in HIV-positive individuals with metabolic complications.

BACKGROUND: Individuals with HIV infection and peripheral metabolic complications have impaired basal myocardial insulin sensitivity that is related to left ventricular (LV) diastolic dysfunction. It is unknown whether interventions shown to be effective in improving peripheral insulin sensitivity can improve basal myocardial insulin sensitivity and diastolic function in people with HIV and peripheral metabolic complications. OBJECTIVE: In a pilot study, we evaluated whether the peroxisome proliferator-activated receptor-gamma (PPAR-γ) agonist pioglitazone or combined endurance and resistance exercise training improves basal myocardial insulin sensitivity and diastolic function in HIV+ adults with peripheral metabolic complications. DESIGN: Twenty-four HIV+ adults with metabolic complications including peripheral insulin resistance were randomly assigned to 4 months of pioglitazone (PIO; 30 mg/d) or supervised, progressive endurance and resistance exercise training (EXS; 90-120 min/d, 3 d/wk). Basal myocardial substrate metabolism was quantified by radioisotope tracer methodology and positron emission tomography (PET) imaging, and LV function was measured by echocardiography. RESULTS: Twenty participants completed the study. Neither PIO nor EXS resulted in a detectable improvement in basal myocardial insulin sensitivity or diastolic function. Post hoc analyses revealed sample sizes of more than 100 participants are needed to detect significant effects of these interventions on basal myocardial insulin sensitivity and function. CONCLUSIONS: PIO or EXS alone did not significantly increase basal myocardial insulin sensitivity or LV diastolic function in HIV+ individuals with peripheral metabolic complications.

Pain is independently associated with impaired physical function in HIV-infected patients.

INTRODUCTION: Human immunodeficiency virus (HIV)-infected patients in the current treatment era can achieve normal life expectancies but experience a high degree of medical and psychiatric comorbidity. Impaired physical function and pain, often in the context of mood disorders and substance abuse, are common in HIV-infected patients. The objective of this study was to investigate the relationship of pain, a modifiable condition, to functional impairment in HIV-infected patients, independent of mood disorders and substance abuse. METHODS: Participants in a prospective cohort of HIV-infected patients at the University of Alabama at Birmingham were included. Patient-reported outcome measures were used to cross-sectionally assess pain and physical function (EuroQOL), mood disorders (PHQ), and substance abuse (ASSIST). Univariate and multivariable models were built with pain as the principal independent variable of interest and three domains of physical function (mobility, self-care, and usual activities) as outcomes. Covariates included mood, substance abuse, age, race, sex, insurance status, HIV transmission risk factor, and CD4+ T-cell count. RESULTS: Among 1,903 participants, 693 (37%) reported pain; 509 (27%) had a mood disorder; and 157 (8.4%) reported current substance abuse. In multivariable models, pain was independently associated with increased odds of impairment in all three domains of physical function investigated-mobility (aOR 10.5, 95% CI 7.6-14.6), self-care (aOR 4.1, 95% CI 2.2-7.4), and usual activities (aOR 5.4, 95% CI 4.0-7.4). DISCUSSION: Pain was associated with substantially increased odds of impairment in physical function. Pain should be an important consideration in HIV primary care. Interventions to address pain and impaired physical function should be investigated.