Immunological and nutritional factors in elderly people in low-level care and their association with mortality

Circulating Natural Killer Cells as Prognostic Value for Non-Small-Cell Lung Cancer Patients Treated with Immune Checkpoint Inhibitors: Correlation with Sarcopenia

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of tumors. Natural killer (NK) cells can play an important role in cancer immune surveillance. The aim of this prospective observational study was to analyze peripheral blood mononuclear cells (PBMCs) in patients with advanced non-small-cell lung cancer (NSCLC) receiving ICIs in order to identify predictive factors for better survival outcomes.

METHODS

Forty-seven stage IV NSCLC patients were enrolled. Patients underwent baseline (T₀) and longitudinal (T₁) evaluations after ICIs. Peripheral immune blood cell counts were analyzed using flow cytometry.

RESULTS

Basal levels of CD3^-CD56⁺ NK cells were higher in patients with controlled disease (DC) compared to progression disease (PD) patients (127 cells/µL vs. 27.8 cells/µL, p < 0.001). Lower NK cell values were independent prognostic factors for shorter overall survival (OS) (HR 0.992; 95% CI 0.987-0.997, p < 0.001) and progression-free survival (PFS) (HR 0.988; 95% CI 0.981-0.994, p < 0.001). During the longitudinal evaluation, CD3^-CD56⁺ NK cells (138.1 cells/µL vs. 127 cells/µL, p = 0.025) and CD56^bright NK cells (27.4 cells/µL vs. 18.1 cells/µL, p = 0.034) significantly increased in the DC group. Finally, lower values of CD3^-CD56⁺ NK cells (28.3 cells/µL vs. 114.6 cells/µL, p = 0.004) and CD56^dim NK cells (13.2 cells/µL vs. 89.4 cells/µL, p < 0.001) were found in sarcopenic patients compared to patients without sarcopenia.

CONCLUSIONS

Peripheral NK cells could represent a non-invasive and useful tool to predict ICI therapy response in NSCLC patients, and the association of low NK cell levels with sarcopenia deserves even more attention in clinical evaluation.

You are what you eat: How to best fuel your immune system

Normal bone marrow (BM) homeostasis ensures consistent production of progenitor cells and mature blood cells. This requires a reliable supply of nutrients in particular free fatty acids, carbohydrates and protein. Furthermore, rapid changes can occur in response to stress such as infection which can alter the demand for each of these metabolites. In response to infection the haematopoietic stem cells (HSCs) must respond and expand rapidly to facilitate the process of emergency granulopoiesis required for the immediate immune response. This involves a shift from the use of glycolysis to oxidative phosphorylation for energy production and therefore an increased demand for metabolites. Thus, the right balance of each dietary component helps to maintain not only normal homeostasis but also the ability to quickly respond to systemic stress. In addition, some dietary components can drive chronic inflammatory changes in the absence of infection or immune stress, which in turn can impact on overall immune function. The optimal nutrition for the best immunological outcomes would therefore be a diet that supports the functions of immune cells allowing them to initiate effective responses against pathogens but also to resolve the response rapidly when necessary and to avoid any underlying chronic inflammation. In this review we discuss how these key dietary components can alter immune function, what is their impact on bone marrow metabolism and how changes in dietary intake of each of these can improve the outcomes of infections.

Effects of 3 months of multi-nutrient supplementation on the immune system and muscle and respiratory function of older adults in aged care (The Pomerium Study): protocol for a randomised controlled trial

INTRODUCTION

Immunosenescence leads to increased morbidity and mortality associated with viral infections and weaker vaccine responses. This has been well documented for seasonal influenza and the current pandemic with SARS-CoV-2 (COVID-19), which disproportionately impact older adults, particularly those in residential aged care facilities. Inadequate nutrient intakes associated with impaired immunity, respiratory and muscle function are likely to augment the effects of immunosenescence. In this study, we test whether the impact of inadequate nutrition can be reversed using multi-nutrient supplementation, consequently enhancing vaccine responses, reducing the risk of viral infections and improving respiratory and muscle function.

METHODS AND ANALYSIS

The Pomerium Study is a 3-month, single-blind, randomised, controlled trial testing the effects of two daily servings of an oral multi-nutrient supplement (330 kcal, 20 g protein, 1.5 g calcium 3-hydroxy-3-methylbutyrate monohydrate (CaHMB), 449 mg calcium, 500 IU vitamin D₃ and 25 vitamins and minerals) on the immune system and muscle and respiratory function of older adults in aged care in Melbourne, Australia. 160 older adults (≥75 years old) will be recruited from aged care facilities and randomised to treatment (multi-nutrient supplement) or control (usual care). The primary outcome is a change in T-cell subsets CD8 + and CD28null counts at months 1 and 3. Secondary outcomes measured at baseline and month 3 are multiple markers of immunosenescence (also at 1 month), body composition (bioimpedance), handgrip strength (dynamometer), physical function (short physical performance battery), respiratory function (spirometry) and quality of life (EQ-5D-5L). Incidence and complications of COVID-19 and/or viral infections (ie, hospitalisation, complications or death) will be recorded throughout the trial, including 3 months after supplementation is ceased.

ETHICS AND DISSEMINATION

This study was approved by Melbourne Health Human Research Ethics Committee (Ref No. HREC/73985/MH-2021, ERM Ref No. RMH73985, Melbourne Health Site Ref No. 2021.115). Written informed consent will be obtained from participants. Results will be published in peer-reviewed journals and made available to key aged care stakeholders, including providers, residents, and government bodies.

TRIAL REGISTRATION NUMBER

ACTRN12621000420842.

Quality of diet and level of physical performance related to inflammatory markers in community-dwelling frail, elderly people

OBJECTIVE

The aim of this study was to assess whether diet quality and functional status were associated with serum levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in frail, elderly, community-dwelling individuals.

METHODS

Seventy-eight frail, elderly individuals (age ≥65 y, usual gait speed <0.6 m/s and Mini Nutritional Assessment <24) participated in this cross-sectional study from the National Home Healthcare Services in Gangbuk-gu, Seoul, South Korea. Diet quality was assessed using mean adequacy ratio (MAR) of the diet, which was calculated by averaging the sum of the nutrient adequacy ratios (NAR) for the intakes of energy, protein, and 11 micronutrients. Grip strength was measured as an indicator of muscle strength, and short physical performance battery (SPPB) was measured as an indicator of physical performance. The levels of the inflammatory markers IL-6 and TNF-α were obtained from serum samples.

RESULTS

MAR and NAR scores for phosphorus; vitamins A, B₁, and B₆; and niacin were negatively associated with IL-6 (β = -0.006, -0.004, -0.004, -0.007, -0.004, and -0.005, respectively; P < 0.05). SPPB score, as well as NAR scores for vitamin B₆, niacin, and vitamin C, were negatively associated with TNF-α (β = -0.098, -0.006, -0.006, and -0.004, respectively; P < 0.05).

CONCLUSION

MAR of the diet was inversely associated with IL-6 concentration in frail elderly individuals, and higher SPPB score was associated with lower levels of TNF-α. Results from the present study suggest that improving diet quality and physical performance might lower levels of inflammation in this frail, elderly population.

Impact of preoperative hand grip strength on morbidity following gastric cancer surgery

BACKGROUND

Sarcopenia is a decrease in both muscle mass and strength. It remains unclear whether sarcopenia is associated with morbidity after gastric cancer surgery. This study evaluated the impact of sarcopenia on the morbidity of gastric cancer surgery.

METHODS

A total of 293 gastric cancer patients who underwent curative surgery between May 2011 and June 2013 were retrospectively examined. Patients with performance status 3 or 4 were excluded. Preoperative lean body mass (LBM) was evaluated by bioelectrical impedance analysis and expressed as LBM index. Preoperative muscle function was measured by hand grip strength (HGS). The cutoff values were the gender-specific lowest 20 %. Grade 2 or higher morbidities, as retrospectively evaluated by the Clavien-Dindo classification, were obtained from the patient record. The risk factors for morbidity were examined by univariate and multivariate analyses.

RESULTS

Morbidity was observed in 39 patients (13.3 %), including 7 with pancreatic leakage, 12 with anastomotic leakage, and 4 with intraabdominal abscesses, but no mortality was observed. The univariate analysis showed that male gender, total gastrectomy, splenectomy, and a low HGS were significant risk factors for morbidity. A low LBM was not a significant risk factor. A low HGS, male gender, and total gastrectomy remained significant in the multivariate analysis.

CONCLUSIONS

A low hand grip strength was a significant risk factor for morbidity after gastric cancer surgery. The importance of the hand grip strength as a risk factor should be examined in future prospective studies.

Pollinosis and all-cause mortality among middle-aged and elderly Japanese: a population-based cohort study

BACKGROUND

Having an allergic disease may have health implications beyond those more commonly associated with allergy given that previous epidemiological studies have suggested that both atopy and allergy are linked to mortality. More viable immune functioning among the elderly, as indicated by the presence of an allergic disease, might therefore be associated with differences in all-cause mortality.

OBJECTIVE

Using data from a Japanese cohort, this study examined whether having pollinosis (a form of allergic rhinitis) in a follow-up survey could predict all-cause and cause-specific mortality.

METHODS

Data came from the Komo-Ise cohort, which at its 1993 baseline recruited residents aged 40-69 years from two areas in Gunma prefecture, Japan. The current study used information on pollinosis that was obtained from the follow-up survey in 2000. Mortality and migration data were obtained throughout the follow-up period up to December 2008. Proportional hazard models were used to examine the relation between pollinosis and mortality.

RESULTS

At the 2000 follow-up survey, 12% (1088 of 8796) of respondents reported that they had pollinosis symptoms in the past 12 months. During the 76 186 person-years of follow-up, 748 died from all causes. Among these, there were 37 external, 208 cardiovascular, 74 respiratory, and 329 neoplasm deaths. After adjusting for potential confounders, pollinosis was associated with significantly lower all-cause [hazard ratio 0.57 (95% confidence interval = 0.38-0.87)] and neoplasms mortality [hazard ratio 0.48 (95% confidence interval = 0.26-0.92)].

CONCLUSIONS AND CLINICAL RELEVANCE

Having an allergic disease (pollinosis) at an older age may be indicative of more viable immune functioning and be protective against certain causes of death. Further research is needed to determine the possible mechanisms underlying the association between pollinosis and mortality.

Proinflammatory status influences NK cells subsets in the elderly

Aging is associated to dysfunctional changes in the immune system, a process termed immunosenescence. Elderly individuals usually present chronic low level inflammation, likely as the consequence of continued exposure to antigens combined with poor immune function, increases in production of pro-inflammatory cytokines by effector memory and senescent T cells and macrophages. This condition not only results from, but also drives immunosenescence. Aging affects all cell components of the immune system, including NK cells and its different subsets (CD56dimCD16+, CD56brightCD16+/- and CD56-CD16+). In particular, the percentage of total NK cells is increased in healthy aging and centenarians, whereas there is a decrease in the CD56bright NK cell subset and an expansion of CD56-CD16+ NK cells. However, the causes of these alterations on NK cells in old donors are not fully understood. In this work we analyse NK cell subsets in the elderly in relation with markers of inflammation and health status. The results show that there is a positive correlation between the number of total NK cells and the body mass index (BMI), while the number of CD56bright NK cells negatively correlates with the levels of C-reactive protein (CRP), supporting that chronic inflammation is involved in the decrease of this NK cell subset.