Dissecting drivers of immune activation in chronic HIV-1 infection

Association of Fatty Acid Signatures with HIV Viremia in Pregnancy

Omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFAs) are vital for fetal metabolic programming and immunomodulation. Higher n-6:n-3 ratios, reflecting a proinflammatory eicosanoid profile, are associated with adverse perinatal outcomes. Limited data exist, however, on n-6 and n-3 PUFAs specifically in the context of HIV and pregnancy. Our objective was to assess HIV clinical factors associated with PUFA signatures in pregnant persons with HIV (PWH). In this observational cohort, third trimester plasma PUFA concentrations (six n-6 PUFAs, four n-3 PUFAs) were measured, each as a percent of total fatty acid content, via esterification and gas chromatography in pregnant PWH enrolled from 2009 to 2011 in the Nutrition substudy of the Pediatric HIV/AIDS Cohort Study. PUFA ratios (n-6:n-3) were calculated. Exposures assessed were first/second trimester CD4 count (<200 vs. >200 cells/mm3), HIV RNA viral load (VL) (VL >400 vs. <400 copies/mL), and protease inhibitor (PI) versus non-PI antiretroviral therapy (ART). Linear regression models using generalized estimating equations were fit to assess mean differences and their 95% confidence intervals (CIs) in n-6:n-3 by each exposure, adjusted for potential confounders. Of 264 eligible pregnant PWH, the median age was 27 years, 12% had CD4 counts <200 cells/mm3, and 56% had VL ≥400 copies/mL in the first/second trimesters. PUFA concentrations and ratios were similar by CD4 count and PI exposure. n-3 concentrations were lower in PWH with VL ≥400 versus <400 copies/mL (median 2.8% vs. 3.0%, p < .01, respectively); no differences were observed for n-6 concentrations by VL. In models adjusted for age, education, tobacco use, body mass index, and PI-based ART, n-6:n-3 was higher in those with VL ≥400 copies/mL (mean difference: 1.6; 95% CI: 0.79-2.48, p = .0001). Therefore, PUFA signatures in viremic pregnant PWH reflect a proinflammatory eicosanoid milieu. Future studies should evaluate associations of proinflammatory PUFA signatures with adverse perinatal outcomes in PWH.

HBcAb Positivity as a Risk Factor for Missing HIV RNA Undetectability after the 3TC+DTG Switch

Hepatitis B Core antibody (HBcAb) positivity is the surrogate marker of hepatitis B occult infection. This condition is not a contraindication for switching to two-drug (2DR) antiretroviral therapy; however, the removal of tenofovir may contribute to poor control of HBV replication. A multicentre retrospective cohort study investigated the impact of HBcAb positivity on HIV control in patients switching to a 2DR with Lamivudine and Dolutegravir (3TC-DTG). In this study, a comparison analysis was conducted between HBcAb-positive and -negative PLWH regarding HIV-RNA suppression, considering: (1): Target Not Detected (TND) < 20 cp/mL; (2) Target Detected (TD) < 20 cp/mL; and (3) Detectable > 20 cp/mL and <50 cp/mL and >50 copies/mL. A total of 267 patients on 2DR with 3TC-DTG were included. In comparison to HBcAb-negative, HBcAb-positive patients were older (45 years [35-54]) and had a lower CD4+ nadir (248 vs. 349 cells/mmc, p = 0.007). No difference in the maintenance of virological suppression was present in the two groups of patients before the switch. Although no patient had an HIV-RNA > 20 cp/mL after the switch, significantly fewer HBcAb-positive compared with -negative subjects resulted in TND at 12, 24, and 36 months after the switch: 52 (69.3%) versus 164 (85.4%), p = 0.004, 50 [72.5%] versus 143 [89.9%], p = 0.001, and 30 [66.7%] versus 90 [92.8%], p = 0.001, respectively. HBcAb positivity is associated with an increased risk of suboptimal HIV suppression during the 36 months after 3TC/DTG simplification. This finding reinforces the relevance of the OBI condition in PLWH and raises the issue of careful virological monitoring of such cases.

Macrophages: Key Cellular Players in HIV Infection and Pathogenesis

Although cells of the myeloid lineages, including tissue macrophages and conventional dendritic cells, were rapidly recognized, in addition to CD4+ T lymphocytes, as target cells of HIV-1, their specific roles in the pathophysiology of infection were initially largely neglected. However, numerous studies performed over the past decade, both in vitro in cell culture systems and in vivo in monkey and humanized mouse animal models, led to growing evidence that macrophages play important direct and indirect roles as HIV-1 target cells and in pathogenesis. It has been recently proposed that macrophages are likely involved in all stages of HIV-1 pathogenesis, including virus transmission and dissemination, but above all, in viral persistence through the establishment, together with latently infected CD4+ T cells, of virus reservoirs in many host tissues, the major obstacle to virus eradication in people living with HIV. Infected macrophages are indeed found, very often as multinucleated giant cells expressing viral antigens, in almost all lymphoid and non-lymphoid tissues of HIV-1-infected patients, where they can probably persist for long period of time. In addition, macrophages also likely participate, directly as HIV-1 targets or indirectly as key regulators of innate immunity and inflammation, in the chronic inflammation and associated clinical disorders observed in people living with HIV, even in patients receiving effective antiretroviral therapy. The main objective of this review is therefore to summarize the recent findings, and also to revisit older data, regarding the critical functions of tissue macrophages in the pathophysiology of HIV-1 infection, both as major HIV-1-infected target cells likely found in almost all tissues, as well as regulators of innate immunity and inflammation during the different stages of HIV-1 pathogenesis.

Sex modifies the risk of HIV-associated obstructive lung disease in Ugandans postpneumonia

OBJECTIVES

Spirometric abnormalities are frequent, and obstructive lung disease (OLD) is a common comorbidity among people with HIV (PWH). HIV increases the risk of many comorbidities to a greater degree in women than in men. Few studies have evaluated whether sex modifies the HIV-associated risk of OLD.

DESIGN AND METHODS

To evaluate the associations between sex and HIV with abnormal lung function, women and men with and without HIV underwent spirometric testing after completing therapy for pneumonia, including tuberculosis (TB), in Kampala, Uganda. OLD was defined as a postbronchodilator forced expiratory volume in the first second to forced vital capacity (FEV 1 /FVC) ratio less than 0.70. Associations between sex, HIV, and lung function were evaluated using multivariable regression models including sex-by-HIV interaction terms after adjusting for age, BMI, smoking status, and TB status.

RESULTS

Among 348 participants, 147 (42%) were women and 135 (39%) were HIV-positive. Sixteen (11%) women and 23 men (11%) had OLD. The HIV-sex interaction was significant for obstructive lung disease ( P  = 0.04). In the adjusted stratified analysis, women with HIV had 3.44 (95% CI 1.11-12.0; P  = 0.04) increased odds of having OLD compared with men with HIV. Women without HIV did not have increased odds of having OLD compared with men without HIV.

CONCLUSION

HIV appears to increase the risk of OLD to a greater degree in women than in men in an urban Ugandan setting. The mechanistic explanation for this interaction by sex remains unclear and warrants further study.

Body Composition Changes Over the Menopausal Transition in Women With and Without Human Immunodeficiency Virus

BACKGROUND

Women are at risk for weight gain during the transition to menopause, but few have examined the contribution of menopause to weight gain in women with human immunodeficiency virus (WWH).

METHODS

From 2000 to 2013, participants (621 WWH; 218 without HIV [WWOH]) from the Women's Interagency HIV Study were categorized by menopausal phase using serial measures of anti-Müllerian hormone (AMH). Multivariable linear mixed models examined the association of menopausal phase with body mass index (BMI) and waist circumference (WC) trajectory, stratified by HIV status.

RESULTS

In models controlled for chronologic age, the estimated effects (95% confidence interval) of menopausal phase on annual rate of BMI change across early perimenopause, late perimenopause, and menopause, respectively, compared to premenopause were -0.55% (-.80 to -.30), -0.29% (-.61 to .03), and -0.67% (-1.12 to -.20) in WWH, whereas estimated effects were 0.43% (-.01 to .87) and 0.15% (-.42 to .71) across early and late perimenopause, respectively, and -0.40% (-1.24 to .45) across menopause in WWOH. The estimated effects on rate of WC change were negative across early perimenopause (-0.21% [-.44 to .03]) and menopause (-0.12% [-.5 to .26]) and positive across late perimenopause (0.18% [-.10 to .45]) in WWH, and positive across all 3 menopausal phases in WWOH, but these effects were not statistically significant.

CONCLUSIONS

In WWH, the menopausal transition was associated with BMI and WC trajectories that were mostly in a negative direction and opposite from WWOH after adjusting for age, suggesting that HIV blunts weight gain during the menopausal transition.

Harnessing Autophagy to Overcome Antigen-Specific T-Cell Dysfunction: Implication for People Living with HIV-1

Like other chronic viral infections, HIV-1 persistence inhibits the development of antigen-specific memory T-cells, resulting in the exhaustion of the immune response and chronic inflammation. Autophagy is a major lysosome-dependent mechanism of intracellular large-target degradation such as lipid and protein aggregates, damaged organelles, and intracellular pathogens. Although it is known that autophagy may target HIV-1 for elimination, knowledge of its function as a metabolic contributor in such viral infection is only in its infancy. Recent data show that elite controllers (EC), who are HIV-1-infected subjects with natural and long-term antigen (Ag)-specific T-cell protection against the virus, are characterized by distinct metabolic autophagy-dependent features in their T-cells compared to other people living with HIV-1 (PLWH). Despite durable viral control with antiretroviral therapy (ART), HIV-1-specific immune dysfunction does not normalize in non-controller PLWH. Therefore, the hypothesis of inducing autophagy to strengthen their Ag-specific T-cell immunity against HIV-1 starts to be an enticing concept. The aim of this review is to critically analyze promises and potential limitations of pharmacological and dietary interventions to activate autophagy in an attempt to rescue Ag-specific T-cell protection among PLWH.

Lung function and collagen 1a levels are associated with changes in 6 min walk test distance during treatment of TB among HIV-infected adults: a prospective cohort study

BACKGROUND

Patients with tuberculosis (TB) and HIV often present with impairments in lung function and exercise capacity after treatment. We evaluated clinical and immunologic variables associated with a minimum clinically important difference (MCID) in the change in the 6 min walk test distance during the first 24 weeks of antiretroviral (ART) and anti-tubercular therapy.

METHODS

Adults initiating ART and anti-TB treatment in the setting of newly-diagnosed HIV and pulmonary TB were enrolled in a prospective cohort study in South Africa. Patients underwent 6 min walk tests and spirometry at weeks 0, 4, 12, and 24 and biomarker level measurements early during treatment, at weeks 0, 4, and 12, when inflammation levels are typically elevated. Biomarkers included matrix metalloproteinases-1 (MMP-1), tissue inhibitor of MMP (TIMP)-1, collagen 1a, IL-6, IL-8, vascular cell adhesion molecule 1 (VCAM-1), C-X-C motif chemokine 10 (CXCL-10), CXCL-11, macrophage colony-stimulating factor (M-CSF), plasminogen activator, vascular endothelial growth factor, and chemokine (C-C) motif-2 (CCL-2). An MCID was derived statistically, and achievement of an MCID was modeled as the outcome using logistic regression model.

RESULTS

Eighty-nine patients walked an average of 393 (± standard deviation = 69) meters at baseline, which increased by an average of 9% (430 ± 70 m) at week 24. The MCID for change in walk distance was estimated as 41 m. Patients experiencing an MCID on treatment had worse lung function, lower 6 min walk test distance, higher levels of proinflammatory biomarkers including TIMP-1 and M-CSF, and lower levels of collagen 1a at baseline. Experiencing an MCID during treatment was associated with increases in forced expiratory volume in 1-s [odds ratio (OR) = 1.17, 95% confidence interval (CI) = 1.05-1.33] and increases in blood collagen 1a levels (OR = 1.31, 95%CI 1.06-1.62).

CONCLUSIONS

ART and TB treatment are associated with substantial improvements in 6 min walk test distance over time. Achievement of an MCID in the 6 min walk test in this study was associated with more severe disease at baseline and increases in collagen 1a levels and lung function during therapy.