Effects of in utero antiretroviral exposure on mitochondrial DNA levels, mitochondrial function and oxidative stress

OBJECTIVES

HIV and antiretroviral (ART) exposure in utero may have deleterious effects on the infant, but uncertainty still exists. The objective of this study was to evaluate aspects of mitochondrial DNA (mtDNA) content, mitochondrial function and oxidative stress simultaneously in placenta, umbilical cord blood and infant blood in HIV/ART-exposed infants compared with uninfected controls.

METHODS

HIV-1-infected pregnant women and HIV-1-uninfected healthy pregnant controls were enrolled in the study prospectively. Placenta and umbilical cord blood were obtained at delivery and infant blood was obtained within 48 h of delivery. mtDNA content was determined for each specimen. Nuclear [subunit IV of cytochrome c-oxidase (COX IV)]- and mitochondrial (COX II)-encoded polypeptides of the oxidative phosphorylation enzyme cytochrome c-oxidase were quantified in cord and infant blood. Placental mitochondria malondialdehyde (MDA) concentrations were measured as a marker of oxidative stress.

RESULTS

Twenty HIV-positive/HIV-exposed and 26 control mother-infant pairs were enrolled in the study. All HIV-infected women and their infants received ART. Placental MDA concentration and mtDNA content in placenta and cord blood were similar between groups. The cord blood COX II:IV ratio was lower in the HIV-positive group than in the controls, whereas the infant peripheral blood mtDNA content was higher in the HIV-exposed infants, but the infant peripheral blood COX II:IV ratio was similar. No infant had clinical evidence of mitochondrial disease or acquired HIV infection. In multivariable regression analyses, the significant findings in cord and infant blood were both most associated with HIV/ART exposure.

CONCLUSIONS

HIV-exposed infants showed reduced umbilical cord blood mitochondrial enzyme expression with increased infant peripheral blood mitochondrial DNA levels, the latter possibly reflecting a compensatory mechanism to overcome HIV/ART-associated mitochondrial toxicity.

Alcohol and dietary factors associate with gut integrity and inflammation in HIV-infected adults

OBJECTIVES

HIV-infected adults have heightened monocyte activation and inflammation, at least partially as a consequence of altered gut integrity. The role of dietary factors in microbial translocation and inflammation and their downstream effect on markers of cardiovascular disease (CVD) have not been explored. Our purpose was to describe the longitudinal dietary patterns of HIV-infected adults, and to examine the relationship between dietary intake, gut integrity, inflammation and subclinical markers of CVD in HIV-infected adults.

METHODS

We conducted a secondary analysis of 147 HIV-infected participants in a 96-week randomized clinical trial of rosuvastatin as primary CVD prevention. Dietary intake was assessed using dietary recall; plasma gut integrity, monocyte activation and inflammation markers were measured using an enzyme-linked immunosorbent assay (ELISA); and CVD risk was assessed using carotid ultrasound and the coronary artery calcium score. Linear mixed models were used to analyse longitudinally measured biomarkers.

RESULTS

The median age was 45 years and 78% of patients were male. At baseline, participants consumed a mean (standard deviation) of 108 (70) g of fat daily, 19 (15.6) g of fibre, 266 (186) g of carbohydrates and 15.6 (5.9) g of protein; 45% of the sample consumed alcohol. Over time, alcohol consumption was associated with several markers of gut integrity and inflammation (all P < 0.05).

CONCLUSIONS

HIV-infected adults in a contemporary, high-resource setting have poor dietary patterns. Alcohol use was associated with worse gut integrity and increased inflammation, while other aspects of diet (fibre, carbohydrates and fat) were not. These data add to growing evidence illustrating the need for a better understanding of the effect of lifestyle factors on comorbidities in HIV-infected adults.

Lipoprotein-associated phospholipase A2 and cardiovascular disease risk in HIV infection

OBJECTIVES

HIV-infected patients on antiretroviral therapy (ART) have an increased cardiovascular disease (CVD) risk as a result of heightened inflammation and immune activation, despite at times having normal lipids and few traditional risk factors. Biomarkers are needed to identify such patients before a clinical event. Lipoprotein-associated phospholipase A2 (Lp-PLA2 ) predicts CVD events in the general population. This study investigated the relationship between Lp-PLA2 and markers of CVD risk, systemic inflammation, immune activation, and coagulation in HIV infection.

METHODS

One hundred subjects on stable ART with normal fasting low-density lipoprotein (LDL) cholesterol were enrolled in the study. Plasma Lp-PLA2 concentrations were measured by enzyme-linked immunosorbent assay (ELISA; > 200 ng/mL was considered high CVD risk). Subclinical atherosclerosis, endothelial function, inflammation, immune activation and fasting lipids were also evaluated.

RESULTS

The median age of the patients was 47 years and 77% were male. Median (range) Lp-PLA2 was 209 (71-402) ng/mL. Fifty-seven per cent of patients had Lp-PLA2 concentrations > 200 ng/mL. Lp-PLA2 was positively correlated with soluble markers of inflammation or immune activation (tumour necrosis factor receptor-II, intercellular and vascular cellular adhesion molecules, and CD14; all R = 0.3; P < 0.01), and negatively correlated with coagulation markers (D-dimer and fibrinogen; both R = -0.2; P < 0.04). Lp-PLA2 was not correlated with lipids, coronary artery calcium score, or flow-mediated vasodilation, but trended towards a significant correlation with carotid intima-media thickness (R = 0.2; P = 0.05).

CONCLUSIONS

In this population with stable ART and normal LDL cholesterol, Lp-PLA2 was in the high CVD risk category in the majority of subjects. Lp-PLA2 appears to be associated with inflammation/immune activation, but also with anti-thrombotic effects. Lp-PLA2 may represent a valuable early biomarker of CVD risk in HIV infection before subclinical atherosclerosis can be detected.