Effect of anti-retroviral therapy on oxidative stress in hospitalized HIV-infected adults with and without TB

Oxidative stress, microparticles, and E-selectin do not depend on HIV suppression

BACKGROUND

Oxidative stress and inflammation are considered predictors of diseases associated with aging. Markers of oxidative stress, inflammation, and endothelial activation were investigated in people with HIV on antiretroviral treatment to determine whether they had an immunosenescent phenotype that might predispose to the development of premature age-related diseases.

PATIENTS AND METHODS

This study was conducted on 213 subjects with HIV. The control groups consisted of healthy HIV-negative adults. The level of oxidative stress was measured by assessing the production of malondialdehyde levels, which were detected by thiobarbituric acid reactive substance (TBARS) assay. The level of microparticles indicated the presence of inflammation and endothelial activation was measured by E-selectin levels. Significant differences were determined by appropriate statistical tests, depending on the distribution of variables. Relationships between continuous variables were quantified using Spearman's rank correlation coefficient.

RESULTS

TBARS, and microparticle and E-selectin levels were significantly higher in untreated and treated subjects with HIV compared with HIV-negative controls (P<0.001). The levels of the investigated markers were not significantly different between untreated and treated patients and no significant correlation of these markers was found with CD4+ count, CD4+/CD8+ ratio, and the number of HIV-1 RNA copies.

CONCLUSIONS

Elevated markers of oxidative stress, inflammatory and endothelial activation were independent of the virologic and immunologic status of people with HIV. These results support the hypothesis that residual viremia in cellular reservoirs of various tissues is a key factor related to the premature aging of the immune system and predisposition to the premature development of diseases associated with aging.

Changes in the balance of Th17/Treg cells and oxidative stress markers in patients with HIV‑associated pulmonary tuberculosis who develop IRIS

Tuberculosis (TB) is the most common opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV) infection and is one of the primary causes of death from AIDS. The increased accessibility to highly active antiretroviral therapy (HAART) has significantly improved the clinical outcome of patients with HIV infection. However, following ART, rapid restoration of the immune system leads to immune reconstitution inflammatory syndrome (IRIS). Oxidative stress and innate immunity play a role in TB-associated IRIS (TB-IRIS). The present study investigated the changes that occur in oxidative stress markers and T helper (Th)17/regulatory T (Treg) cell balance and their significance in IRIS patients with HIV-associated pulmonary TB. A total of 316 patients with HIV-associated pulmonary TB were treated with HAART and followed up regularly for 12 weeks. Those who developed IRIS were included in the IRIS group (n=60), while the remaining patients were included in the non-IRIS group (n=256). The changes in plasma oxidative stress markers superoxide dismutase (SOD) and malondialdehyde (MDA) were detected with the ELISA, and the ratio of Th17 to Treg cells in whole blood were analyzed before and after treatment through the flow cytometric assay. Following treatment, MDA and Th17 cells levels were significantly increased while SOD and Treg cells levels were decreased in the IRIS group (P<0.05) compared with before treatment. In the non-IRIS group, a non-significant decrease was observed in SOD levels (P>0.05), while the MDA levels significantly decreased compared with before treatment (P<0.05) and the Th17 and Treg cells levels were both significantly increased (P<0.05). After treatment, compared with the non-IRIS group, the IRIS group showed a significant increase in MDA and Th17 cells and decrease in SOD and Treg cells levels (P<0.05). In addition, Th17 cells levels were positively correlated with MDA but negatively correlated with SOD levels. Treg levels were negatively correlated with MDA and positively correlated with SOD levels (P<0.05). The area under the curve values of serum MDA and SOD, Th17 and Treg levels predicting the occurrence of IRIS were 0.738, 0.883, 0.722 and 0.719, respectively (P<0.05). These results indicated that the above parameters have certain diagnostic value for the occurrence of IRIS. The occurrence of IRIS in patients with HIV-associated pulmonary TB may be associated with oxidative stress and Th17/Treg cell imbalance.

Antiretroviral Therapy-Induced Dysregulation of Gene Expression and Lipid Metabolism in HIV+ Patients: Beneficial Role of Antioxidant Phytochemicals

Human immunodeficiency virus (HIV) infection has continued to be the subject of study since its discovery nearly 40 years ago. Significant advances in research and intake of antiretroviral therapy (ART) have slowed the progression and appearance of the disease symptoms and the incidence of concomitant diseases, which are the leading cause of death in HIV+ persons. However, the prolongation of ART is closely related to chronic degenerative diseases and pathologies caused by oxidative stress (OS) and alterations in lipid metabolism (increased cholesterol levels), both of which are conditions of ART. Therefore, recent research focuses on using natural therapies to diminish the effects of ART and HIV infection: regulating lipid metabolism and reducing OS status. The present review summarizes current information on OS and cholesterol metabolism in HIV+ persons and how the consumption of certain phytochemicals can modulate these. For this purpose, MEDLINE and SCOPUS databases were consulted to identify publications investigating HIV disease and natural therapies and their associated effects.

High Mycobacterium tuberculosis Bacillary Loads Detected by Tuberculosis Molecular Bacterial Load Assay in Patient Stool: a Potential Alternative for Nonsputum Diagnosis and Treatment Response Monitoring of Tuberculosis

Not all patients produce sputum, yet most available TB tests use sputum. We investigated the utility of a novel RNA-based quantitative test, the tuberculosis molecular bacterial load assay (TB-MBLA), for the detection and quantification of Mycobacterium tuberculosis in stool. Stools from 100 adult individuals were treated with OMNIgene-sputum reagent and tested using Xpert MTB/RIF ultra (Xpert ultra), auramine O smear microscopy (smear), mycobacterial growth indicator tube (MGIT), and Lowenstein-Jensen (LJ) cultures. The remaining portions were frozen at −20°C and later tested by TB-MBLA. MGIT sputum culture was used as a TB confirmatory test and reference for stool tests. Sixty-one of 100 participants were already confirmed TB positive by MGIT sputum culture, 20 (33%) of whom were HIV coinfected. TB-MBLA detected M. tuberculosis in 57/100 stool samples, including 49 already confirmed for TB. The mean bacterial load measured by stool TB-MBLA was 5.67 ± 1.7 log₁₀ estimated CFU (eCFU) per mL in HIV-coinfected participants, which was higher than the 4.83 ± 1.59 log₁₀ eCFU per mL among the HIV-negative participants (P = 0.04). The sensitivities (95% confidence intervals [CI]) of stool assays were 80% (68 to 89) and 90% (79 to 98) for TB-MBLA and Xpert ultra, which were both higher than the 44% (32 to 58), 64% (51 to 76), and 62% (45 to 77) for smear, MGIT, and Lowenstein-Jensen (LJ) stool cultures, respectively. The specificity (95% CI) of stool assays was highest for smear, at 97% (87 to 100), followed by Xpert ultra at 91% (76 to 98), TB-MBLA at 79% (63 to 90), LJ at 80% (64 to 91), and MGIT at 62% (45 to 77). Twenty-six percent of MGIT and 21% of LJ stool cultures were indeterminate due to contamination. Detection and quantification of viable M. tuberculosis bacilli in stool raises its utility as an alternative to sputum as a sample type for TB diagnosis.

IMPORTANCE This paper highlights the value of stool as a sample type for diagnosis of tuberculosis. While other studies have used DNA-based assays like the Xpert MTB/RIF and culture to detect Mycobacterium tuberculosis in stool, this is the first study that has applied TB-MBLA, an RNA-based assay, to quantify TB bacteria in stool. The high microbial density and diversity in stool compromises the specificity and sensitivity of culture-based tests due to overgrowth of non-M. tuberculosis flora. Consequently, TB-MBLA becomes the most sensitive and specific test for the detection and quantification of viable TB bacteria in stool. Most crucially, this study raises the possibility of a nonsputum alternative sample type for diagnosis of TB among people who have difficulty in producing sputum.

Reproducibility of the Ribosomal RNA Synthesis Ratio in Sputum and Association with Markers of Mycobacterium tuberculosis Burden

There is a critical need for improved pharmacodynamic markers for use in human tuberculosis (TB) drug trials. Pharmacodynamic monitoring in TB has conventionally used culture or molecular methods to enumerate the burden of Mycobacterium tuberculosis organisms in sputum. A recently proposed assay called the rRNA synthesis (RS) ratio measures a fundamentally novel property, how drugs impact ongoing bacterial rRNA synthesis. Here, we evaluated RS ratio as a potential pharmacodynamic monitoring tool by testing pretreatment sputa from 38 Ugandan adults with drug-susceptible pulmonary TB. We quantified the RS ratio in paired pretreatment sputa and evaluated the relationship between the RS ratio and microbiologic and molecular markers of M. tuberculosis burden. We found that the RS ratio was highly repeatable and reproducible in sputum samples. The RS ratio was independent of M. tuberculosis burden, confirming that it measures a distinct new property. In contrast, markers of M. tuberculosis burden were strongly associated with each other. These results indicate that the RS ratio is repeatable and reproducible and provides a distinct type of information from markers of M. tuberculosis burden. IMPORTANCE This study takes a major next step toward practical application of a novel pharmacodynamic marker that we believe will have transformative implications for tuberculosis. This article follows our recent report in Nature Communications that an assay called the rRNA synthesis (RS) ratio indicates the treatment-shortening of drugs and regimens. Distinct from traditional measures of bacterial burden, the RS ratio measures a fundamentally novel property, how drugs impact ongoing bacterial rRNA synthesis.

Oxidative Stress and Trace Elements in Pulmonary Tuberculosis Patients During 6 Months Anti-tuberculosis Treatment

Pulmonary tuberculosis (TB) is a well-known cause of imbalance in oxidative stress (OS) status and trace element levels. However, little information is available for targeting the correlation between OS and trace elements in pulmonary TB patients. The aim of our study was to analyze the OS status and its correlation with trace elements in patients initially and during 6 months anti-TB treatment. Eighty-six newly diagnosed pulmonary TB patients were consecutively recruited, and 112 age- and sex-matched healthy controls participated in the study. Serum markers of OS and trace elements levels were tested and analyzed in all subjects during 6 months anti-TB treatment. Compared with healthy controls, significantly increased level of malondialdehyde (MDA), decreased glutathione (GSH) level, superoxide dismutase (SOD), and catalase (CAT) activities were found in TB patients. The activities of SOD and CAT and GSH level recovered till normal range at treatment final. Zinc (Zn), selenium (Se), and copper (Cu) concentrations were significantly lower in TB patients in comparison with healthy controls, whereas Zn, Cu, and Se concentrations rise during 6 months anti-TB treatment. Zn was positively correlated with Cu, Se, and GSH, while MDA was negatively correlated with Zn, Se, SOD, and CAT, and SOD was positively correlated with Cu, Zn, and CAT. Our findings indicate that anti-TB treatment could reduce the status of OS and increase the levels of trace elements. The routine assessment of OS markers and element traces may guarantee improved monitoring the anti-TB treatment.

Immune activation and arterial stiffness in lean adults with HIV on antiretroviral therapy

Background

Greater T-cell activation was associated with reduced vascular compliance amongst persons living with HIV (PLWH) especially among overweight and obese individuals. There is a paucity of data regarding immune activation and arterial stiffness amongst PLWH in sub-Saharan Africa (SSA).

Objective

To determine the association between immune activation and arterial stiffness in lean PLWH in SSA.

Method

Forty-eight human immunodeficiency virus positive (HIV+) adults on antiretroviral therapy (ART) >5 years and 26 HIV-negative adults, all with BMI < 25 kg/m² and no history of CVD, were enrolled. The relationship of vascular compliance with circulating CD4+ and CD8+ naïve, memory, activated and senescent T cells, and serum 8-isoprostane was assessed by HIV status.

Results

Increased immune activation was observed in the CD4+ and CD8+ T cells of PLWH, 16.7% vs. 8.9% and 22.0% vs. 12.4% respectively; p < 0.001 (both). Furthermore, a higher proportion of senescent CD4+ T cells were associated with a lower carotid-femoral pulse wave velocity (cfPWV; p = 0.01), whilst a higher proportion of activated CD8+ T cells were associated with a lower carotid-radial pulse wave velocity (crPWV; p = 0.04), after adjustment for BMI and age. However, PLWH also had a higher median carotid-femoral augmentation index (cfAiX) (21.1% vs. 6.0%; p < 0.05) in comparison to their HIV controls.

Conclusion

Our population of lean PLWH had increased immune activation and higher cfAiX, a marker of arterial stiffness, compared to HIV-negative persons. The negative association between immune activation and arterial stiffness as measured by crPWV in PLHW on long-term treatment needs further elucidation.

Multiple Effects of Ascorbic Acid against Chronic Diseases: Updated Evidence from Preclinical and Clinical Studies

Severe disease commonly manifests as a systemic inflammatory process. Inflammation is associated withthe enhanced production of reactive oxygen and nitrogen species and with a marked reduction in the plasma concentrations of protective antioxidant molecules. This imbalance gives rise to oxidative stress, which is greater in patients with more severe conditions such as sepsis, cancer, cardiovascular disease, acute respiratory distress syndrome, and burns. In these patients, oxidative stress can trigger cell, tissue, and organ damage, thus increasing morbidity and mortality. Ascorbic acid (ASC) is a key nutrient thatserves as an antioxidant and a cofactor for numerous enzymatic reactions. However, humans, unlike most mammals, are unable to synthesize it. Consequently, ASC must be obtained through dietary sources, especially fresh fruit and vegetables. The value of administering exogenous micronutrients, to reestablish antioxidant concentrations in patients with severe disease, has been recognized for decades. Despite the suggestion that ASC supplementation may reduce oxidative stress and prevent several chronic conditions, few large, randomized clinical trials have tested it in patients with severe illness. This article reviews the recent literature on the pharmacological profile of ASC and the role of its supplementation in critically ill patients.

An Inflammatory Story: Antibodies in Tuberculosis Comorbidities

Mycobacterium tuberculosis (Mtb) resides in a quarter of the world's population and is the causative agent for tuberculosis (TB), the most common infectious reason of death in humans today. Although cellular immunity has been firmly established in the control of Mtb, there is growing evidence that antibodies may also modulate the infection. More specifically, certain antibody features are associated with inflammation and are divergent in different states of human infection and disease. Importantly, TB impacts not just the healthy but also those with chronic conditions. While HIV represents the quintessential comorbid condition for TB, recent epidemiological evidence shows that additional chronic conditions such as diabetes and kidney disease are rising. In fact, the prevalence of diabetes as a comorbid TB condition is now higher than that of HIV. These chronic diseases are themselves independently associated with pro-inflammatory immune states that encompass antibody profiles. This review discusses isotypes, subclasses, post-translational modifications and Fc-mediated functions of antibodies in TB infection and in the comorbid chronic conditions of HIV, diabetes, and kidney diseases. We propose that inflammatory antibody profiles, which are a marker of active TB, may be an important biomarker for detection of TB disease progression within comorbid individuals. We highlight the need for future studies to determine which inflammatory antibody profiles are the consequences of comorbidities and which may potentially contribute to TB reactivation.