From Wasting to Obesity: The Contribution of Nutritional Status to Immune Activation in HIV Infection.

The impact of human immunodeficiency virus (HIV) infection on innate and adaptive immune activation occurs in the context of host factors, which serve to augment or dampen the physiologic response to the virus. Independent of HIV infection, nutritional status, particularly body composition, affects innate immune activation through a variety of conditions, including reduced mucosal barrier defenses and microbiome dysbiosis in malnutrition and the proinflammatory contribution of adipocytes and stromal vascular cells in obesity. Similarly, T-cell activation, proliferation, and cytokine expression are reduced in the setting of malnutrition and increased in obesity, potentially due to adipokine regulatory mechanisms restraining energy-avid adaptive immunity in times of starvation and exerting a paradoxical effect in overnutrition. The response to HIV infection is situated within these complex interactions between host nutritional health and immunologic function, which contribute to the varied phenotypes of immune activation among HIV-infected patients across a spectrum from malnutrition to obesity

Adipose Tissue T Cells in HIV/SIV Infection

Adipose tissue comprises one of the largest organs in the body and performs diverse functions including energy storage and release, regulation of appetite and other neuroendocrine signaling, and modulation of immuity, among others. Adipocytes reside in a complex compartment where antigen, antigen presenting cells, innate immune cells, and adaptive immune cells interact locally and exert systemic effects on inflammation, circulating immune cell profiles, and metabolic homeostasis. T lymphocytes are a major component of the adipose tissue milieu which are altered in disease states such as obesity and human immunodeficiency virus (HIV) infection. While obesity, HIV infection, and simian immunodeficiency virus (SIV; a non-human primate virus similar to HIV) infection are accompanied by enrichment of CD8+ T cells in the adipose tissue, major phenotypic differences in CD4+ T cells and other immune cell populations distinguish HIV/SIV infection from obesity. Furthermore, DNA and RNA species of HIV and SIV can be detected in the stromal vascular fraction of visceral and subcutaneous adipose tissue, and replication-competent HIV resides in local CD4+ T cells. Here, we review studies of adipose tissue CD4+ and CD8+ T cell populations in HIV and SIV, and contrast the findings with those reported in obesity

Effects on mortality of a nutritional intervention for malnourished HIV-infected adults referred for antiretroviral therapy: a randomised controlled trial.

Malnourished HIV-infected African adults are at high risk of early mortality after starting antiretroviral therapy (ART). We hypothesized that short-course, high-dose vitamin and mineral supplementation in lipid nutritional supplements would decrease mortality

Minimal impact of an iron-fortified lipid-based nutrient supplement on Hb and iron status: a randomised controlled trial in malnourished HIV-positive African adults starting antiretroviral therapy.

Anaemia, redistribution of Fe, malnutrition and heightened systemic inflammation during HIV infection confer an increased risk of morbidity and mortality in HIV patients. We analysed information on Fe status and inflammation from a randomised, double blind, controlled phase-III clinical trial in Lusaka, Zambia and Mwanza, Tanzania. Malnourished patients (n 1815) were recruited at referral to antiretroviral therapy (ART) into a two-stage nutritional rehabilitation programme, randomised to receive a lipid-based nutrient supplement with or without added micronutrients. Fe was included in the intervention arm during the second stage, given from 2 to 6 weeks post-ART. Hb, serum C-reactive protein (CRP), serum ferritin and soluble transferrin receptor (sTfR) were measured at recruitment and 6 weeks post-ART. Multivariable linear regression models were used to assess the impact of the intervention, and the effect of reducing inflammation from recruitment to week 6 on Hb and Fe status. There was no effect of the intervention on Hb, serum ferritin, sTfR or serum CRP. A one-log decrease of serum CRP from recruitment to week 6 was associated with a 1.81 g/l increase in Hb (95% CI 0.85, 2.76; P< 0.001), and a 0.11 log decrease in serum ferritin (95% CI - 0.22, 0.03; P= 0.012) from recruitment to week 6. There was no association between the change in serum CRP and the change in sTfR over the same time period (P= 0.78). In malnourished, HIV-infected adults receiving dietary Fe, a reduction in inflammation in the early ART treatment period appears to be a precondition for recovery from anaemia

Appetite testing in HIV-infected African adults recovering from malnutrition and given antiretroviral therapy.

OBJECTIVE: The Nutritional Support for Africans Starting Antiretroviral Therapy (NUSTART) trial was designed to determine whether nutritional support for malnourished HIV-infected adults starting antiretroviral therapy (ART) can improve early survival. Appetite is related to health outcomes in this population, but the optimal appetite metric for field use is uncertain. We evaluated two measures of appetite with the goal of improving understanding and treatment of malnutrition in HIV-infected adults. DESIGN: Longitudinal cohort study embedded in a clinical trial of vitamin and mineral-fortified, v. unfortified, lipid-based nutritional supplements. SETTING: HIV clinics in Mwanza, Tanzania and Lusaka, Zambia. SUBJECTS: Malnourished (BMI<18.5 kg/m2) HIV-infected adults starting ART. RESULTS: Appetite measurements, by short questionnaire and by weight of maize porridge consumed in a standardized test, were compared across time and correlated with changes in weight. Appetite questionnaire scores, from polychoric correlation, and porridge test results were normally distributed for Tanzanians (n 187) but clustered and unreliable for Zambians (n 297). Among Tanzanian patients, the appetite score increased rapidly from referral for ART, plateaued at the start of ART and then increased slowly during the 12-week follow-up. Change in appetite questionnaire score, but not porridge test, correlated with weight change in the corresponding two-week intervals (P=0.002) or over the whole study (P=0.05) but a point estimate of hunger did not predict weight change (P=0.4). CONCLUSIONS: In Tanzania change in appetite score correlated with weight change, but single point measurements did not. Appetite increases several weeks after the start of ART, which may be an appropriate time for nutritional interventions for malnourished HIV-infected adults

Greater Weight Gain in Treatment-naive Persons Starting Dolutegravir-based Antiretroviral Therapy

Background Recent studies have reported weight gain in virologically suppressed persons living with human immunodeficiency virus (PLWH) switched from older antiretroviral therapy (ART) to newer integrase strand transfer inhibitor (INSTI)–based regimens. In this study, we investigated whether weight gain differs among treatment-naive PLWH starting INSTI-based regimens compared to other ART regimens. Methods Adult, treatment-naive PLWH in the Vanderbilt Comprehensive Care Clinic cohort initiating INSTI-, protease inhibitor (PI)–, and nonnucleoside reverse transcriptase inhibitor (NNRTI)–based ART between January 2007 and June 2016 were included. We used multivariable linear mixed-effects models to generate marginal predictions of weights over time, adjusting for baseline clinical and demographic characteristics. We used restricted cubic splines to relax linearity assumptions and bootstrapping to generate 95% confidence intervals. Results Among 1152 ART-naive PLWH, 351 initiated INSTI-based regimens (135 dolutegravir, 153 elvitegravir, and 63 raltegravir), 86% were male, and 49% were white. At ART initiation, median age was 35 years, body mass index was 25.1 kg/m2, and CD4+ T-cell count was 318 cells/μL. Virologic suppression at 18 months was similar between different ART classes. At all examined study time points, weight gain was highest among PLWH starting dolutegravir. At 18 months, PLWH on dolutegravir gained 6.0 kg, compared to 2.6 kg for NNRTIs (P < .05), and 0.5 kg for elvitegravir (P < .05). PLWH starting dolutegravir also gained more weight at 18 months compared to raltegravir (3.4 kg) and PIs (4.1 kg), though these differences were not statistically significant. Conclusions Treatment-naive PLWH starting dolutegravir-based regimens gained significantly more weight at 18 months than those starting NNRTI-based and elvitegravir-based regimens

Changes in serum phosphate and potassium and their effects on mortality in malnourished African HIV-infected adults starting antiretroviral therapy and given vitamins and minerals in lipid-based nutritional supplements: secondary analysis from the Nutritional Support for African Adults Starting Antiretroviral Therapy (NUSTART) trial.

Malnourished HIV-infected patients starting antiretroviral therapy (ART) are at high risk of early mortality, some of which may be attributed to altered electrolyte metabolism. We used data from a randomised controlled trial of electrolyte-enriched lipid-based nutritional supplements to assess the association of baseline and time-varying serum phosphate and K concentrations with mortality within the first 12 weeks after starting ART. Baseline phosphate results were available from 1764 patients and there were 9096 subsequent serum phosphate measurements, a median of 6 per patient. For serum K there were 1701 baseline and 8773 subsequent measures, a median of 6 per patient. Abnormally high or low serum phosphate was more common than high or low serum K. Controlling for other factors found to affect mortality in this cohort, low phosphate which had not changed from the previous time interval was associated with increased mortality; the same was not true for high phosphate or for high or low K. Both increases and decreases in serum electrolytes from the previous time interval were generally associated with increased mortality, particularly in the electrolyte-supplemented group. The results suggest that changes in serum electrolytes, largely irrespective of the starting point and the direction of change, were more strongly associated with mortality than were absolute electrolyte levels. Although K and phosphate are required for tissue deposition during recovery from malnutrition, further studies are needed to determine whether specific supplements exacerbate physiologically adverse shifts in electrolyte levels during nutritional rehabilitation of ill malnourished HIV patients

A 12 week longitudinal study of microbial translocation and systemic inflammation in undernourished HIV-infected Zambians initiating antiretroviral therapy.

BACKGROUND: Undernourished, HIV-infected adults in sub-Saharan Africa have high levels of systemic inflammation, which is a risk factor for mortality and other adverse health outcomes. We hypothesized that microbial translocation, due to the deleterious effects of HIV and poor nutrition on intestinal defenses and mucosal integrity, contributes to heightened systemic inflammation in this population, and reductions in inflammation on antiretroviral therapy (ART) accompany reductions in translocation. METHODS: HIV-infected, Zambian adults with a body mass index <18.5 kg/m2 were recruited for a pilot study to assess the relationships between microbial translocation and systemic inflammation over the first 12 weeks of ART. To assess microbial translocation we measured serum lipopolysaccharide binding protein (LBP), endotoxin core IgG and IgM, and soluble CD14, and to assess intestinal permeability we measured the urinary excretion of an oral lactulose dose normalized to urinary creatinine (Lac/Cr ratio). Linear mixed models were used to assess within-patient changes in these markers relative to serum C-reactive protein (CRP), tumor necrosis factor-α receptor 1 (TNF-α R1), and soluble CD163 over 12 weeks, in addition to relationships between variables independent of time point and adjusted for age, sex, and CD4+ count. RESULTS: Thirty-three participants had data from recruitment and at 12 weeks: 55% were male, median age was 36 years, and median baseline CD4+ count was 224 cells/μl. Over the first 12 weeks of ART, there were significant decreases in serum levels of LBP (median change -8.7 μg/ml, p = 0.01), TNF-α receptor 1 (-0.31 ng/ml, p < 0.01), and CRP (-3.5 mg/l, p = 0.02). The change in soluble CD14 level over 12 weeks was positively associated with the change in CRP (p < 0.01) and soluble CD163 (p < 0.01). Pooling data at baseline and 12 weeks, serum LBP was positively associated with CRP (p = 0.01), while endotoxin core IgM was inversely associated with CRP (p = 0.01) and TNF-α receptor 1 (p = 0.04). The Lac/Cr ratio was not associated with any serum biomarkers. CONCLUSIONS: In undernourished HIV-infected adults in Zambia, biomarkers of increased microbial translocation are associated with high levels of systemic inflammation before and after initiation of ART, suggesting that impaired gut immune defenses contribute to innate immune activation in this population

Effects on anthropometry and appetite of vitamins and minerals given in lipid nutritional supplements for malnourished HIV-infected adults referred for antiretroviral therapy: results from the NUSTART randomized controlled trial.

BACKGROUND: The evidence base for effects of nutritional interventions for malnourished HIV-infected patients starting antiretroviral therapy (ART) is limited and inconclusive. OBJECTIVE: We hypothesized that both vitamin and mineral deficiencies and poor appetite limit weight gain in malnourished patients starting ART and that vitamin and mineral supplementation would improve appetite and permit nutritional recovery. DESIGN: The randomized controlled Nutritional Support for Africans Starting Antiretroviral Therapy trial was conducted in Mwanza, Tanzania, and Lusaka, Zambia. ART-naive adults referred for ART and with body mass index <18.5 kg/m received lipid-based nutritional supplements either without (LNS) or with added vitamins and minerals (LNS-VM), beginning before ART initiation. Participants were given 30 g/d LNS from recruitment until 2 weeks after starting ART and 250 g/d from weeks 2 to 6 of ART. RESULTS: Of 1815 patients recruited, 365 (20%) died during the study and 813 (45%) provided data at 12 weeks. Controlling for baseline values, anthropometric measures were consistently higher at 12-week ART in the LNS-VM than in the LNS group but statistically significant only for calf and mid-upper arm circumferences and triceps skinfold. Appetite did not differ between groups. Using piecewise mixed-effects quadratic models including all patients and time points, the main effects of LNS-VM were seen after starting ART and were significant for weight, body mass index, and mid-upper arm circumference. CONCLUSIONS: Provision of high levels of vitamins and minerals to patients referred for ART, delivered with substantial macronutrients, increased nutritional recovery but did not seem to act through treatment group differences in appetite