Overproduction of monokines by leukocytes after stimulation with lipopolysaccharide in the elderly

The therapeutic effect of wine-processed Corni Fructus on chronic renal failure in rats through the interference with the LPS/IL-1-mediated inhibition of RXR function

ETHNOPHARMACOLOGICAL RELEVANCE

Corni Fructus, derived from the fruit of Cornus officinalis Sieb. et Zucc, is a widely utilized traditional Chinese medicine (TCM) with established efficacy in the treatment of diverse chronic kidney diseases. Crude Corni Fructus (CCF) and wine-processed Corni Fructus (WCF) are the main processed forms of Corni Fructus. Generally, TCM is often used after processing (paozhi). Despite the extensive use of processed TCM, the underlying mechanisms of processing for most TCMs have been unclear so far.

AIM OF THE STUDY

In this study, an integrated strategy combined renal metabolomics with proteomics was established and investigated the potential processing mechanisms of CCF or WCF on chronic renal failure (CRF) models.

MATERIALS AND METHODS

Firstly, the differences in biochemical parameters and pathological histology were compared to evaluate the effects of CCF and WCF on CRF model rats. Then, the tissue differential metabolites and proteins between CCF and WCF on CRF model rats were screened based on metabolomics and proteomics technology. Concurrently, a combined approach of metabolomics and proteomics was employed to investigate the underlying mechanisms associated with these marker metabolic products and proteins.

RESULTS

Compared to the MG group, there were 27 distinct metabolites and 143 different proteins observed in the CCF-treatment group, while the WCF-treatment group exhibited 24 distinct metabolites and 379 different proteins. Further, the integration interactions analysis of the protein and lipid metabolite revealed that both WCF and CCF improved tryptophan degradation and LPS/IL-1-mediated inhibition of RXR function. WCF inhibited RXR function more than CCF via the modulation of LPS/IL-1 in the CRF model. Experimental results were validated by qRT-PCR and western blotting. Notably, the gene expression amount and protein levels of FMO3 and CYP2E1 among 8 genes influenced by WCF were higher compared to CCF.

CONCLUSION

The results of this study provide a theoretical basis for further study of Corni Fructus with different processing techniques in CRF. The findings also offer guidance for investigating the mechanism of action of herbal medicines in diseases employing diverse processing techniques.

A revisiting of "the hallmarks of aging" in domestic dogs: current status of the literature

A progressive decline in biological function and fitness is, generally, how aging is defined. However, in 2013, a description on the "hallmarks of aging" in mammals was published, and within it, it described biological processes that are known to alter the aging phenotype. These include genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication (inflammation), and changes within the microbiome. This mini-review provides a detailed account of the progress on each of these hallmarks of aging in the domestic dog within the last 5 years. Additionally, when there are gaps in the literature between other mammalian species and dogs, I highlight the aging biomarkers that may be missing for dogs as aging models. I also argue for the importance of dog aging studies to include several breeds of dogs at differing ages and for age corrections for breeds with differing mean lifespans throughout.

Immunosenescence and inflammaging in the aged horse

The equine population in the United States and worldwide now includes a higher percentage of geriatric horses than ever previously recorded, and as methods to treat and manage elderly equids are developed and refined, this aging population will likely continue to expand. A better understanding of how horses age and the effect of age on immunity and disease susceptibility is needed to enable targeted preventative healthcare strategies for aged horses. This review article outlines the current state of knowledge regarding the effect of aging on immunity, vaccine responsiveness, and disease risk in the horse, highlighting similarities and differences to what is observed in aged humans. Horses show similar but milder age-related alterations in immune function to those reported in people. Decreases in lymphocyte proliferation and antibody production and diminished response to vaccination have all been documented in elderly horses, however, increased risk of infectious disease is not commonly reported. Aged horses also show evidence of a proinflammatory state (inflammaging) yet appear less susceptible to the chronic diseases of people for which inflammation is a risk factor. Information is currently lacking as to why the horse does not experience the same risk of age-related disease (e.g., cancer, heart disease, neurodegeneration) as people, although a lack of negative lifestyle habits, differences in diet, exercise, genetics and physiology may all contribute to improved health outcomes in the older horse.

The interaction between aging and protein malnutrition modulates peritoneal macrophage function: An experimental study in male mice

Malnutrition is considered one of the most common problems in the elderly population worldwide and can significantly interfere in health evolution in these individuals, predisposing them to increased infection susceptibility. The immune response triggered by infections comprises several mechanisms, and macrophages play important roles in this response. This study aimed to evaluate mechanisms related to macrophage function in a model of protein malnutrition in the elderly. Two age groups (young: 3-5 months and elderly: 18-19 months) male C57BL/6NTac mice were subjected to protein malnutrition with a low-protein diet (2 %). The nutritional status, hemogram and number of peritoneal cells were affected by both age and nutritional status. Additionally, the spreading capacity as well as the phagocytic and fungicidal activity of peritoneal macrophages were affected by the nutritional status and age of the animal. Interestingly, the percentages of F4/80⁺/CD11b⁺ and CD86⁺ cells were reduced mostly in elderly animals, while the TLR-4⁺ population was more affected by nutritional status than by age. The production of pro-inflammatory cytokines such as TNF-α, IL-1α, and IL-6 was also influenced by nutritional status and/or by age, and malnourished animals of advanced age produced higher amounts of the anti-inflammatory cytokine IL-10. Furthermore, the phosphorylation ratio of the transcription factor NFκB (pNFκB/NFκB) was directly affected by the nutritional status, independently of age. Thus, these results allow us to conclude that aging and protein malnutrition compromise macrophage function, likely affecting their immune function, and in aged protein-malnourished animals, this impairment tends to be more pronounced.

Elevated Expression of TLR2 in Aging Hearts Exacerbates Cardiac Inflammatory Response and Adverse Remodeling Following Ischemia and Reperfusion Injury

This study tested the hypothesis that Toll-like receptor 2 (TLR2) augments the inflammatory responses and adverse remodeling in aging hearts to exacerbate myocardial injury and cardiac dysfunction.

Methods

Old (20-22 months old) and adult (4-6 months old) mice of C57BL/6 wild-type and TLR2 knockout (KO) were subjected to coronary artery ligation (30 minutes) and reperfusion (3 or 14 days). Left ventricle function was assessed using a pressure-volume microcatheter. Cardiac infarct size was determined by histology. Levels of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), matrix metalloproteinase 9 (MMP 9), and collagen I in non-ischemic myocardium were assessed by immunoblotting. Monocyte chemoattractant protein-1 (MCP-1), keratinocyte chemoattractant (KC), and interleukin-6 (IL-6) levels in ischemic and non-ischemic myocardium were measured by enzyme-linked immunosorbent assay (ELISA). TLR2 expression in the myocardium of untreated wild type mice was also measured by immunoblotting.

Results

Higher levels of MCP-1, KC, IL-6 were induced in both ischemic and non-ischemic myocardium of old wild type mice at day 3 and 14 following ischemia/reperfusion (I/R) than those of adult wild type mice. The hyper-inflammatory responses to I/R in aging hearts were associated with elevated levels of myocardial TLR2. TLR2 KO markedly down-regulated the expression of MCP-1, KC, IL-6, ICAM-1 and VCAM-1 in aging hearts at day 3 and 14 following I/R. The down-regulated inflammatory activity in aging TLR2 KO hearts was associated with attenuated production of MMP 9 and collagen I at day 14 and resulted in reduced infarct size and improved cardiac function.

Conclusion

Elevated expression of myocardial TLR2 contributes to the mechanism by which aging exacerbates the inflammatory responses, adverse remodeling and cardiac dysfunction following myocardial I/R in aging.

Cellular metabolism and IL-6 concentrations during stimulated inflammation in primary fibroblasts from small and large dog breeds as they age

The immune system undergoes marked changes during aging characterized by a state of chronic, low-grade inflammation termed 'inflammaging'. We explore this phenomenon in domestic dogs, which are the most morphologically and physiologically diverse group of mammals, with the widest range in body sizes for a single species. Additionally, smaller dogs tend to live significantly longer than larger dogs across all breeds. Body size is intricately linked to mass-specific metabolism and aging rates, which suggests that dogs are exemplary for studies in inflammaging. Dermal fibroblast cells play an important role in skin inflammation, making them a good model for inflammatory patterns across dog breed, body sizes and ages. Here, we examined aerobic and glycolytic cellular metabolism, and IL-6 concentrations in primary fibroblast cells isolated from small and large dog breeds, that were either recently born puppies or old dogs after death. We found no differences in cellular metabolism when isolated fibroblasts were treated with lipopolysaccharide (LPS) from Escherichia coli to stimulate an inflammatory phenotype. Unlike responses observed in mice and humans, there was a less drastic amplification of IL-6 concentration after LPS treatment in the geriatric population of dogs compared with recently born dogs. In young dogs, we also found evidence that untreated fibroblasts from large breeds had significantly lower IL-6 concentrations than observed for smaller breeds. This implies that the patterns of inflammaging in dogs may be distinct and different from other mammals commonly studied.

I mmunosenescence and Inflammaging: Risk Factors of Severe COVID-19 in Older People

Old individuals are more susceptible to various infections due to immunological changes that occur during the aging process. These changes named collectively as "immunosenescence" include decreases in both the innate and adaptive immune responses in addition to the exacerbated production of inflammatory cytokines. This scenario of immunological dysfunction and its relationship with disease development in older people has been widely studied, especially in infections that can be fatal, such as influenza and, more recently, COVID-19. In the current scenario of SARS-CoV-2 infection, many mechanisms of disease pathogenesis in old individuals have been proposed. To better understand the dynamics of COVID-19 in this group, aspects related to immunological senescence must be well elucidated. In this article, we discuss the main mechanisms involved in immunosenescence and their possible correlations with the susceptibility of individuals of advanced age to SARS-CoV-2 infection and the more severe conditions of the disease.

Diversity of aging of the immune system classified in the cotton rat (Sigmodon hispidus) model of human infectious diseases

Susceptibility and declined resistance to human pathogens like respiratory syncytial virus (RSV) at old age is well represented in the cotton rat (Sigmodon hispidus). Despite providing a preferred model of human infectious diseases, little is known about aging of its adaptive immune system. We aimed to define aging-related changes of the immune system of this species. Concomitantly, we asked whether the rate of immunological alterations may be stratified by physiological aberrations encountered during aging. With increasing age, cotton rats showed reduced frequencies of T cells, impaired induction of antibodies to RSV, higher incidence of aberrations of organs and signs of lipemia. Moreover, old animals expressed high biological heterogeneity, but the age-related reduction of T cell frequency was only observed in those specimens that displayed aberrant organs. Thus, cotton rats show age-related alterations of lymphocytes that can be classified by links with health status.

Age-Associated Decline in Dendritic Cell Function and the Impact of Mediterranean Diet Intervention in Elderly Subjects

INTRODUCTION

Aging is accompanied by increased susceptibility to infection and age-associated chronic diseases. It is also associated with reduced vaccine responses, which is often attributed to immunosenescence and the functional decline of the immune system. Immunosenescence is characterized by a chronic, low-grade, inflammatory state termed inflammaging. Habitants of Mediterranean (MED) regions maintain good health into old age; often attributed to MED diets.

HYPOTHESIS

Adoption of a MED-diet by elderly subjects, in Norfolk (UK), may improve immune responses of these individuals and in particular, dendritic cell (DC) function.

EXPERIMENTAL APPROACH

A total of 120 elderly subjects (65-79 years old) recruited onto the Nu-AGE study, a multicenter European dietary study specifically addressing the needs of the elderly, across five countries, and were randomized to the control or MED-diet groups, for one year. Blood samples were taken pre- and post-intervention for DC analysis and were compared with each other, and to samples obtained from 45 young (18-40 years old) subjects. MED-diet compliance was assessed using high performance liquid chromatography-with tandem mass spectrometry analysis of urine samples. Immune cell and DC subset numbers and concentrations of secreted proteins were determined by flow cytometric analysis.

RESULTS

As expected, reduced myeloid DC numbers were observed in blood samples from elderly subjects compared with young. The elevated secretion of the adipokine, resistin, after ex vivo stimulation of peripheral blood mononuclear cells from elderly subjects, was significantly reduced after MED-diet intervention.

CONCLUSION

This study provides further evidence of numerical and functional effects of aging on DCs. The MED-diet showed potential to impact on the aging immune cells investigated and could provide an economical approach to address problems associated with our aging population.

Effects of age on systemic inflamatory response syndrome and results of coronary bypass surgery

Background

Coronary artery bypass (CAB) surgery triggerssystemic inflammatory response syndrome (SIRS) via severalmechanisms. Moreover, age is directly correlated with SIRS.We evaluated the effect of age on SIRS and postoperativeoutcome after CAB surgery.

Methods

We retrospectively reviewed the records of 229 patients who had undergone CAB surgery. The patients were divided into three groups according to age: group 1, < 40 years (n = 61); group 2, 40–75 years (n = 83); and group 3, > 75 years old (n = 85). Pre- and peri-operative data were assessed in all patients. SIRS was diagnosed according to the criteria established by Boehme.

Results

The average pre-operative EuroSCORE value in group 3 was higher than in the other groups and body surface areas were significantly lower in group 3 than in the other groups (p < 0.05). The postoperative SIRS rates were 68.9% in group 1, 84.3% in group 2 and 91.8% in group 3 (group 1 vs group 3; p < 0.05). Mortality rates were not significantly different between the groups (p > 0.05). The predictive factors for SIRS were age, EuroSCORE rate, on-pump CAB surgery and intra-aortic balloon pump use.

Conclusion

Age was an important risk factor for SIRS during the postoperative period after CAB.

Immune Dysfunction in Aged Horses

The aging process in people is associated with changes in adaptive and innate immune responses. Similar changes occur in aged horses. Age-related progressive impairment in the ability to respond to pathogen challenge and an increased inflammatory reactivity may predispose geriatric horses to many diseases of old age. Specific recommendations for immune modification of older horses, including an age-appropriate vaccination schedule, are not currently available. In addition, the effect of old age on risk of infectious disease is poorly documented. More work is needed to better understand the interactions of age on immunity, vaccine response, and disease risk in horses.

Reduced levels of cytosolic DNA sensor AIM2 are associated with impaired cytokine responses in healthy elderly

OBJECTIVE

Human aging is associated with remodeling of the immune system. While most studies on immunosenescence have focused on adaptive immunity, the effects of aging on innate immunity are not well understood. Here, we investigated whether aging affects cytokine responses to a wide range of well-defined pattern recognition receptor (PRR) ligands, such as ligands for Toll-like receptors (TLRs), C-type lectin receptors (CLRs), NOD-like receptors (NLRs), retinoic-acid-inducible gene-I like receptors (RLRs) and the cytosolic DNA sensor absent in melanoma 2 (AIM2).

METHOD

Blood was collected from 16 young (20-39 years) and 18 elderly (60-84 years) healthy participants. Pro-inflammatory cytokine (TNF-α, IL-1β, IL-6, and IL-8) production in a whole blood assay (WBA) after stimulation with TLR ligands (Pam3csk4, poly(I:C), LPS, CpG), CLR ligand (β-glucan), NLR ligand (MDP), RLR ligands (5'ppp-dsDNA and poly(I:C)/lyovec) and the AIM2 ligand (poly(dA:dT) was assessed by ELISA. TLR2 and TLR4 expression by leukocytes and monocytes was determined by flow-cytometry. Expression of AIM2 by peripheral blood mononuclear cells (PBMC) was assessed by qRT-PCR and Western blot.

RESULT

Cytokine responses to Pam3csk4, poly(I:C) and CpG, β-glucan, MDP, 5'ppp-dsDNA and poly(I:C)/lyovec were comparable between young and old participants. We observed a higher IL-8 response following stimulation of elderly blood samples with the TLR4 ligand LPS, which was associated with higher proportions of TLR4 expressing monocytes. Interestingly, stimulation of whole blood cells with the AIM2 ligand poly(dA:dT) resulted in significantly lower cytokine responses in old participants. Moreover, these lower cytokine responses were associated with lower AIM2 protein expression and activation in PBMC of old participants.

CONCLUSION

Our findings reveal an age-dependent reduction of AIM2 expression and activation which may explain reduced cytokine responses to the cytosolic DNA mimic poly(dA:dT) in healthy elderly individuals. Reduced AIM2-mediated sensing with age may contribute to increased vulnerability to bacterial or viral infections in the elderly.

Bloodstream infections in internal medicine

Bloodstream infections (BSI) carry a heavy burden of morbidity and mortality in modern internal medicine wards (IMW). These wards are often filled with elderly subjects with several risk factors for BSI, such as multiple comorbidities, polypharmacy, immunosuppression, and indwelling devices. Diagnosing BSI in such a setting might require a high degree of suspicion, since the clinical presentation could be affected by underlying conditions and concomitant medications, which might delay the administration of an appropriate antimicrobial therapy, an event strongly and unfavorably influencing survival. Furthermore, selecting the appropriate antimicrobial therapy to treat these patients is becoming an increasingly complex task in which all possible benefits and costs should be carefully analyzed from patient and public health perspectives. Only a specialized, continuous, and interdisciplinary approach could really improve the management of IMW patients in an era of increasing antimicrobial resistance and complexity of care.

Sepsis-induced Cardiac Mitochondrial Damage and Potential Therapeutic Interventions in the Elderly

The incidence of sepsis and its attendant mortality risk are significantly increased with aging. Thus, severe sepsis in the elderly is likely to become an emerging concern in critical care units. Cardiac dysfunction is an important component of multi-organ failure after sepsis. In our laboratory, utilizing a pneumonia-related sepsis animal model, our research has been focused on the mechanisms underlying sepsis-induced cardiac failure. In this review, based on findings from others and ours, we discussed age-dependent decay in mitochondria and the role of mitochondrial reactive oxygen species (mtROS) in sepsis-induced cardiac inflammation and autophagy. Our recent discovery of a potential signal transduction pathway that triggers myocardial mitochondrial damage is also discussed. Because of the significance of mitochondria damage in the aging process and in sepsis pathogenesis, we hypothesize that specific enhancing mitochondrial antioxidant defense by mitochondria-targeted antioxidants (MTAs) may provide important therapeutic potential in treating elder sepsis patients. In this review, we summarized the categories of currently published MTA molecules and the results of preclinical evaluation of MTAs in sepsis and aging models.

Pro-inflammatory capacity of classically activated monocytes relates positively to muscle mass and strength

In mice, monocytes that exhibit a pro-inflammatory profile enter muscle tissue after muscle injury and are crucial for clearance of necrotic tissue and stimulation of muscle progenitor cell proliferation and differentiation. The aim of this study was to test if pro-inflammatory capacity of classically activated (M1) monocytes relates to muscle mass and strength in humans. This study included 191 male and 195 female subjects (mean age 64.2 years (SD 6.4) and 61.9 ± 6.4, respectively) of the Leiden Longevity Study. Pro-inflammatory capacity of M1 monocytes was assessed by ex vivo stimulation of whole blood with Toll-like receptor (TLR) 4 agonist lipopolysaccharide (LPS) and TLR-2/1 agonist tripalmitoyl-S-glycerylcysteine (Pam₃Cys-SK₄), both M1 phenotype activators. Cytokines that stimulate M1 monocyte response (IFN-γ and GM-CSF) as well as cytokines that are secreted by M1 monocytes (IL-6, TNF-α, IL-12, and IL-1β) were measured. Analyses were adjusted for age, height, and body fat mass. Upon stimulation with LPS, the cytokine production capacity of INF-γ, GM-CSF, and TNF-α was significantly positively associated with lean body mass, appendicular lean mass and handgrip strength in men, but not in women. Upon stimulation with Pam₃Cys-SK₄, IL-6; TNF-α; and Il-1β were significantly positively associated with lean body mass and appendicular lean in women, but not in men. Taken together, this study shows that higher pro-inflammatory capacity of M1 monocytes upon stimulation is associated with muscle characteristics and sex dependent.

Postoperative outcomes following pancreaticoduodenectomy: how should age affect clinical practice?

Background

Pancreaticoduodenectomy is an increasingly common procedure performed for both benign and malignant disease. There are conflicting data regarding the safety of pancreatic resection in older patients. Potentially modifiable perioperative risk factors to improve outcomes in older patients have yet to be determined.

Methods

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database for 2008 to 2009 was used for this retrospective analysis. Patients undergoing pancreaticoduodenectomy were identified and divided into those above and below the age of 65. Preoperative risk factors and postoperative morbidity and mortality were evaluated.

Results

Among 2,045 patients included in this analysis, 994 patients were >65 years (48.6%) while 1,051 were (less than or equal to) 65 years (51.4%). Thirty-day mortality was higher in the older age group compared to the younger age group 3.6% vs. 1.9% respectively, P = 0.017, odds ratio 1.94. Older patients had a higher incidence of unplanned intubation, ventilator support >48 h and septic shock compared with younger patients. On multivariate logistic regression, after adjusting for other 30-day postoperative occurrences (significant at the P <0.1 level) only septic shock was independently associated with a higher odds of mortality, unplanned intubation, and ventilator support >48 h in older patients compared with younger patients.

Conclusions

This report from a population-based database is the first to highlight postoperative sepsis as an independent risk factor for mortality and morbidity in older patients undergoing pancreatic resection. Careful perioperative management addressing this issue is essential for patients over the age of 65.

Zinc: dietary intake and impact of supplementation on immune function in elderly

The diet in the elderly does not provide a sufficient level of nutrients needed to maintain an adequate healthy status leading to micronutrient deficiencies and impaired immune response with subsequent development of degenerative diseases. Nutrient "zinc" is a relevant micronutrient involved in maintaining a good integrity of many body homeostatic mechanisms, including immune efficiency, owing to its requirement for the biological activity of many enzymes, proteins and for cellular proliferation and genomic stability. Old people aged 60-65 years and older have zinc intakes below 50% of the recommended daily allowance on a given day. Many causes can be involved: among them, altered intestinal absorption, inadequate mastication, psychosocial factors, drugs interactions, altered subcellular processes (zinc transporters (Zip and ZnT family), metallothioneins, divalent metal transporter-1). Zinc supplementation may remodel the immune alterations in elderly leading to healthy ageing. Several zinc trials have been carried out with contradictory data, perhaps due to incorrect choice of an effective zinc supplementation in old subjects showing subsequent zinc toxic effects on immunity. Old subjects with specific IL-6 polymorphism (GG allele carriers; named C-) are more prone for zinc supplementation than the entire old population, in whom correct dietary habits with foods containing zinc (Mediterranean diet) may be sufficient in restoring zinc deficiency and impaired immune response. We summarise the main causes of low zinc dietary intake in elderly reporting an update on the impact of zinc supplementation upon the immune response also on the basis of individual IL-6 polymorphism.

Effects of human Toll-like receptor 1 polymorphisms on ageing

Background

Advanced age results in crucial alterations of the innate and adaptive immune system leading to functional defects resulting in infection and chronic diseases. Toll-like receptors (TLR) recognize pathogenic structures and are important in the immune response to infections and vaccination. However, the role of TLR single nucleotide polymorphisms (SNP) is poorly understood in the setting of human ageing. This study investigated the impact of the TLR1 SNPs A743G and T1805G on ageing in different age groups from two European populations.

Results

The TLR1 genotypes 743AA/1805GG (TLR1neg) are associated with a TLR1 negative phenotype, impaired function and susceptibility to tuberculosis. Carriers of heterozygous 743AG/1805TG and homozygous 743GG/1805TT genotypes (TLR1pos) have a TLR1 positive phenotype. By comparing healthy young and old German donors, the old group showed a tendency to carry more TLR1neg and less homozygous TLR1pos genotypes. Anti-inflammatory Interleukin (IL)-1 receptor antagonist (Ra) was significantly elevated in supernatants of mononuclear cells from old German subjects with a TLR1pos genotype in contrast to those with the 743AA genotype. Healthy old individuals and nonagenarians from Italy displayed significantly higher frequencies of TLR1pos genotypes than the old group from Germany. The data show that tumor-necrosis-factor (TNF)α, CXCL8 and CCL2 levels were higher in old donors from Germany than in plasma levels from old Italian donors. TNFα and CCL2 levels were significantly raised in old German individuals compared to Italian nonagenarians. German and Italian donors with the TLR1neg genotype basically produced more CCL2 than older European donors with TLR1pos genotypes.

Conclusion

The higher frequency of the TLR1pos genotype in elderly Italian subjects may result from different ethnic populations. Lower inflammatory mediator release of aged Italian individuals is probably due to different background in nutrition, diet, genetics and to psychological aspects. Elderly donors carrying TLR1pos genotypes basically release more anti-inflammatory IL-1Ra and less inflammatory CCL2 suggesting a decline of the pro-inflammatory status found in ageing and, therefore, this may define an anti-inflammatory phenotype. Future studies are needed to elucidate the association of a TLRpos genotype with decreased susceptibility to infections and reduced risk to develop artherosclerosis.

Aging is associated with chronic innate immune activation and dysregulation of monocyte phenotype and function

Chronic inflammation in older individuals is thought to contribute to inflammatory, age-related diseases. Human monocytes are comprised of three subsets (classical, intermediate and nonclassical subsets), and despite being critical regulators of inflammation, the effect of age on the functionality of monocyte subsets remains to be fully defined. In a cross-sectional study involving 91 healthy male (aged 20-84 years, median 52.4) and 55 female (aged 20-82 years, median 48.3) individuals, we found age was associated with an increased proportion of intermediate and nonclassical monocytes (P = 0.002 and 0.04, respectively) and altered phenotype of specific monocyte subsets (e.g. increased expression of CD11b and decreased expression of CD38, CD62L and CD115). Plasma levels of the innate immune activation markers CXCL10, neopterin (P < 0.001 for both) and sCD163 (P = 0.003) were significantly increased with age. Whilst similar age-related changes were observed in both sexes, monocytes from women were phenotypically different to men [e.g. lower proportion of nonclassical monocytes (P = 0.002) and higher CD115 and CD62L but lower CD38 expression] and women exhibited higher levels of CXCL10 (P = 0.012) and sCD163 (P < 0.001) but lower sCD14 levels (P < 0.001). Monocytes from older individuals exhibit impaired phagocytosis (P < 0.05) but contain shortened telomeres (P < 0.001) and significantly higher intracellular levels of TNF both at baseline and following TLR4 stimulation (P < 0.05 for both), suggesting a dysregulation of monocyte function in the aged. These data show that aging is associated with chronic innate immune activation and significant changes in monocyte function, which may have implications for the development of age-related diseases.

Repletion of zinc in zinc-deficient cells strongly up-regulates IL-1β-induced IL-2 production in T-cells

Mild zinc deficiency in humans negatively affects IL-2 production resulting in declined percentages of cytolytic T cells and decreased NK cell lytic activity, which enhances the susceptibility to infections and malignancies. T-cell activation is critically regulated by zinc and the normal physiological zinc level in T-cells slightly lies below the optimal concentration for T-cell functions. A further reduction in zinc level leads to T-cell dysfunction and autoreactivity, whereas high zinc concentrations (100 μM) were shown to inhibit interleukin-1 (IL-1)-induced IL-1 receptor kinase (IRAK) activation. In this study, we investigated the molecular mechanism by which zinc regulates the IL-1β-induced IL-2 expression in T-cells. Zinc supplementation to zinc-deficient T-cells increased intracellular zinc levels by altering the expression of zinc transporters, particularly Zip10 and Zip12. A zinc signal was observed in the murine T-cell line EL-4 6.1 after 1 h of stimulation with IL-1β, measured by specific zinc sensors FluoZin-3 and ZinPyr-1. This signal is required for the phosphorylation of MAPK p38 and NF-κB subunit p65, which triggers the transcription of IL-2 and strongly increases its production. These results indicate that short-term zinc supplementation to zinc-deficient T-cells leads to a fast rise in zinc levels which subsequently enhance cytokine production. In conclusion, low and excessive zinc levels might be equally problematic for zinc-deficient subjects, and stabilized zinc levels seem to be essential to avoid negative concentration-dependent zinc effects on T-cell activation.

Chronic resveratrol intake reverses pro-inflammatory cytokine profile and oxidative DNA damage in ageing hybrid mice

Thymic involution and shrinkage of secondary lymphoid organs are leading causes of the deterioration of the T-cell compartment with age. Inflamm-aging, a sustained inflammatory status, has been associated with chronic diseases and shortened longevity. This is the first study to investigate the effect of treating aging hybrid mice with long-term, low-dose resveratrol (RSV) in drinking water by assessing multiple immunological markers and profiles in the immune system. We found that hybrid mice exhibited marked age-related changes in the CD3+CD4+, C3+CD8+, CD4+CD25+, CD4M and CD8M surface markers. RSV reversed surface phenotypes of old mice to that of young mice by maintaining the CD4+ and CD8+ population in splenocytes as well as reducing CD8+CD44+ (CD8M) cells in the aged. RSV also enhanced the CD4+CD25+ population in old mice. Interestingly, pro-inflammatory status in young mice was transiently elevated by RSV but it consequently mitigated the age-dependent increased pro-inflammatory cytokine profile while preserving the anti-inflammatory cytokine condition in the old mice. Age-dependent increase in 8OHdG, an oxidative DNA damage marker was ameliorated by RSV. Immunological-focused microarray gene expression analysis showed that only the CD72 gene was significantly downregulated in the 12-month RSV-treated mice compared to age-matched controls. Our study indicates that RSV even at low physiological relevant levels is able to affect the immune system without causing marked gene expression changes.

Age-associated alteration in innate immune response in captive baboons

Baboons are an ideal model for studies of human inflammatory response due to their physiological and immunological similarities to people; however; little is known about how age affects immune function in the baboon. We sought to determine if baboons show age-related innate immune changes similar to that described in people. Age was correlated with increased serum C-reactive protein and interleukin-6 or, however, no change in interleukin-10 concentration was observed (n = 120 baboons). Cytokine release from unstimulated peripheral blood mononuclear cells as well as following immune (lipopolysaccharide) stimulation increased with age. When whole blood was assayed, both lipopolysaccharide stimulated and unstimulated samples showed an age-related increase in interleukin-6 response, although the unstimulated cytokine response was reduced compared with that observed in peripheral blood mononuclear cells. Tumor necrosis factor-α response was not related to age. Cytokine response in lipopolysaccharide-stimulated whole blood was negatively correlated with serum DHEA-S concentration and positively correlated with TGF-β concentration.

Dysregulation of human Toll-like receptor function in aging

Studies addressing immunosenescence in the immune system have expanded to focus on the innate as well as the adaptive responses. In particular, aging results in alterations in the function of Toll-like receptors (TLRs), the first described pattern recognition receptor family of the innate immune system. Recent studies have begun to elucidate the consequences of aging on TLR function in human cohorts and add to existing findings performed in animal models. In general, these studies show that human TLR function is impaired in the context of aging, and in addition there is evidence for inappropriate persistence of TLR activation in specific systems. These findings are consistent with an overarching theme of age-associated dysregulation of TLR signaling that likely contributes to the increased morbidity and mortality from infectious diseases found in geriatric patients.

Age-associated changes to pathogen-associated molecular pattern-induced inflammatory mediator production in dogs

OBJECTIVE

To determine whether older dogs will have a more pronounced pro-inflammatory response and blunted anti-inflammatory response to pathogen-associated molecular patterns (PAMPs) compared with younger dogs.

DESIGN

Prospective.

SETTING

University teaching hospital.

ANIMALS

Thirty-eight privately owned sexually altered dogs of various ages.

INTERVENTIONS

Blood was collected for HCT, WBC count, plasma biochemical analysis, and whole blood culture. Whole blood was stimulated with lipopolysaccharide (LPS) or, lipoteichoic acid or, peptidoglycan or, addition of phosphate-buffered saline. Tumor necrosis factor (TNF), interleukin (IL)-6, and IL-10 production from whole blood were compared among young, middle aged, and geriatric dogs.

MEASUREMENTS AND MAIN RESULTS

LPS, lipoteichoic acid, and peptidoglycan stimulated significant TNF, IL-6, and IL-10 production from canine whole blood compared with phosphate-buffered saline. Whole blood from geriatric dogs had a blunted IL-10 response to LPS stimulation and middle-aged dogs had increased LPS-induced TNF production compared with the other groups.

CONCLUSION

PAMPs from gram-positive and gram-negative bacteria stimulate TNF, IL-6, and IL-10 production from canine whole blood. The inflammatory mediator response to PAMPs from gram-negative bacteria alters with age and may be one factor contributing to mortality in geriatric dogs with sepsis.

The effect of comorbidity and age on hospital mortality and length of stay in patients with sepsis

PURPOSE

Sepsis is believed to be responsible for substantial health care burden, but there is limited information about its magnitude and the factors affecting health outcomes in Asian population. The aim of the study was to assess the disease burden of sepsis and to test the usefulness of Charlson Comorbidity Index (CCI) and age as risk-adjusted hospital mortality predictors in patients with sepsis using hospital administrative database.

METHODS

A retrospective cohort study of hospital discharge database from 2004 to 2007 to identify cases with sepsis, comorbidity, and organ failure using the International Statistical Classification of Diseases and Related Health Problems, 9th Revision, Australian Modification codes was conducted.

RESULTS

Of 305,637 hospitalized patients over 4 years, 6929 (2.27%) patients had sepsis, with 1216 (17.5%) patients associated with intensive care unit (ICU) admission. The mortality rates increased consistently in patients with CCI ranging from none to low, moderate and high grade for both patients with ICU admission (39.4%, 51.6%, 55.9%, and 54.3% respectively; P < .001) and patients without ICU admission (6.4%, 8.7%, 17.1%, and 25.3% respectively; P < .001). Logistic regression analysis showed that CCI (odds ratio, 11.8; high versus none) and age (odds ratio, 8.46; aged 85 years and older versus aged 18-54 years old) were significant and independent predictors of hospital mortality. Similar results were seen with hospital length of stay by zero-truncated negative binomial regression model analysis.

CONCLUSION

The sepsis-related mortality and resource utilization are high in this population as well. Comorbidities and advanced age were some of the most important contributors to hospital mortality and resource utilization.

Human innate immunosenescence: causes and consequences for immunity in old age

The past decade has seen an explosion in research focusing on innate immunity. Through a wide range of mechanisms including phagocytosis, intracellular killing and activation of proinflammatory or antiviral cytokine production, the cells of the innate immune system initiate and support adaptive immunity. The effects of aging on innate immune responses remain incompletely understood, particularly in humans. Here we review advances in the study of human immunosenescence in the diverse cells of the innate immune system, including neutrophils, monocytes, macrophages, natural killer and natural killer T (NKT) cells and dendritic cells-with a focus on consequences for the response to infection or vaccination in old age.

The immune system and the impact of zinc during aging

The trace element zinc is essential for the immune system, and zinc deficiency affects multiple aspects of innate and adaptive immunity. There are remarkable parallels in the immunological changes during aging and zinc deficiency, including a reduction in the activity of the thymus and thymic hormones, a shift of the T helper cell balance toward T helper type 2 cells, decreased response to vaccination, and impaired functions of innate immune cells. Many studies confirm a decline of zinc levels with age. Most of these studies do not classify the majority of elderly as zinc deficient, but even marginal zinc deprivation can affect immune function. Consequently, oral zinc supplementation demonstrates the potential to improve immunity and efficiently downregulates chronic inflammatory responses in the elderly. These data indicate that a wide prevalence of marginal zinc deficiency in elderly people may contribute to immunosenescence.

Changes in experimental stroke outcome across the life span

Acute ischemic stroke is a leading cause of mortality and disability in the elderly. Age is the most important nonmodifiable risk factor for stroke, yet many preclinical models continue to examine only young male animals. It remains unclear how experimental stroke outcomes change with aging and with biologic sex. If sex differences are present, it is not known whether these reflect an intrinsic differing sensitivity to stroke or are secondary to the loss of estrogen with aging. We subjected both young and aging mice of both sexes to middle cerebral artery occlusion (MCAO). Young female mice had smaller strokes compared with age-matched males, an effect that was reversed by ovariectomy. Stroke damage increased with aging in female mice, whereas male mice had decreased damage after MCAO. Blood-brain barrier (BBB) permeability changes are correlated with infarct size. However, aging mice had significantly less edema formation, an effect that was independent of sex and histologic damage. Differences in the cellular response to stroke occur across the life span in both male and female mice. These differences need to be considered when developing relevant therapies for stroke patients, the majority of whom are elderly.

The role of stress factors during aging of the immune system

This manuscript reviews current evidence suggesting that aging of the immune system (immunosenescence) may be closely related to chronic stress and stress factors. Healthy aging has been associated with emotional distress in parallel to increased cortisol to dehydroepiandrosterone (DHEA) ratio. The impaired DHEA secretion together with the increase of cortisol results in an enhanced exposure of lymphoid cells to deleterious glucocorticoid actions. The lack of appropriated growth hormone signaling during immunosenescence is also discussed. It follows that altered neuroendocrine functions could be underlying several immunosenescence features. Indeed, changes in both innate and adaptive immune responses during aging are also similarly reported during chronic glucocorticoid exposure. In addition, chronically stressed elderly subjects may be particularly at risk of stress-related pathology because of further alterations in both neuroendocrine and immune systems. The accelerated senescent features induced by chronic stress include higher oxidative stress, reduced telomere length, chronic glucocorticoid exposure, thymic involution, changes in cellular trafficking, reduced cell-mediated immunity, steroid resistance, and chronic low-grade inflammation. These senescent features are related to increased morbidity and mortality among chronically stressed elderly people. Overall, these data suggest that chronic stress leads to premature aging of key allostatic systems involved in the adaptation of the organisms to environmental changes. Stress management and psychosocial support may thus promote a better quality of life for elderly people and at the same time reduce hospitalization costs.

Granulocyte macrophage--colony-stimulating factor-dependent proliferation is impaired in macrophages from senescence-accelerated mice

A senescence-accelerated (SAMP8) mouse model was used to determine the effect of aging on the immune system. We produced in vitro bone marrow-derived macrophages from SAMP8 mice and compared them against senescence-resistant, long-lived mice (SAMR1). Although macrophages from both strains of mice proliferated in a similar manner in response to monocyte-colony-stimulating factor (M-CSF), SAMP8 macrophages showed an impaired response to granulocyte macrophage-colony-stimulating factor (GM-CSF). Similar levels of external regulated kinases (ERK)1/2 and signaling transducer and activator of transcription 5 (STAT5) phosphorylation were observed in macrophages from both strains of mice. The lack of proliferation was not caused by the induction of apoptosis. Differentiation of bone marrow cells into dendritic cells was similar in both strains of mice, as was the induction of major histocompatibility complex (MHC) class II molecules by interferon-gamma (IFN-gamma). Finally, we determined the density of Langerhans cells in vivo in the skin of the two mouse strains, but no differences were found.

Epigenetics, aging, and autoimmunity

Immune senescence is associated with a decline in T- and B-cell immune responses. It is, therefore, perhaps surprising that aging is linked to the appearance of serological and clinical autoimmunity. Here we review the mechanisms that contribute to the increase in inflammatory and autoimmune responses in aging. The bulk of this review will focus on aging-associated changes in epigenetic mechanisms, and in particular DNA methylation, as this has emerged as an attractive mechanistic link between aging and autoimmunity.

Elderly patients have more severe biliary infections: influence of complement-killing and induction of TNFalpha production

BACKGROUND

Biliary bacteria are more common in elderly patients and cause more serious illnesses. The reasons for this are unclear. We noted previously that bacterial serum-sensitivity and induction of TNFalpha production in sera (iTNFsera) were associated with severe biliary infections. We examined the influence of age and these factors on illness severity.

METHODS

Three-hundred and forty patients were studied. Gallstones and bile were cultured. Illness was staged as none (no clinical infection or inflammation), SIRS (fever, leukocytosis), severe (cholangitis, abscess, empyema), or MODS (bacteremia, hypotension, organ dysfunction/failure). Bacterial serum-sensitivity and TNFalpha induction were measured. Younger (< 70 years) and elderly (> or = 70 years) patients were compared.

RESULTS

Biliary bacteria were more common in elderly (64% vs 41%, P < .0001). Among patients with biliary bacteria, the elderly had more serious illnesses: none: 44% younger, 19% elderly; SIRS: 16% younger, 22% elderly; severe: 22% younger, 21% elderly; MODS 18% younger, 38% elderly (P = .003). Bacteria from elderly patients induced more TNFalpha (580 vs 310 pg/ml, P = .023). In both groups, serum-sensitive bacteria caused infectious manifestations and induced abundant TNFalpha; however, serum-resistant bacteria from elderly usually (69%) caused infectious manifestations and abundant TNFalpha, while serum-resistant bacteria from younger patients rarely (8%) caused infectious manifestations and minimal TNFalpha. Elderly patients with high iTNFsera bacteria had more severe illnesses.

CONCLUSIONS

Biliary bacteria were more common in elderly patients and produced more serious illnesses. Many younger patients with biliary bacteria displayed no infectious manifestations. Elderly patients harbored more virulent bacteria, and had a heightened response to high iTNFsera bacteria, as well as bacteria largely tolerated by younger patients.

Toll-like receptors in older adults

Toll-like receptors (TLRs) recognize a limited number of conserved elements in pathogens and, by activating antigen-presenting cells such as dendritic cells and monocytes and macrophages, play a crucial role in the immune response to infection and vaccination. Most data on TLR function in the context of human aging focus on responses to lipopolysaccharide, an integral component of gram-negative bacteria, which signals through TLR4. However, such studies have not led to a consensus conclusion and are limited by differences in epidemiological and laboratory methods. A recent comprehensive evaluation of TLR function in monocytes from older adults was conducted using a multivariable mixed statistical model to account for covariates. It was found that cytokine production after TLR1/2 engagement, which is essential for the recognition of triacylated lipopeptides found in a variety of bacteria, is substantially lower in monocytes from older adults. The upregulation of costimulatory proteins such as CD80, essential for optimal activation of T cells, on monocytes from older adults was less for all TLR ligands tested than for cells from young individuals, and the extent of CD80 upregulation predicted subsequent antibody response to influenza immunization. These and other consequences of aging on human TLR function may impair activation of the immune response and contribute to poorer vaccine responses and greater morbidity and mortality from infectious diseases in older adults. Such age-associated alterations have particular relevance in view of the interest in TLR agonists as therapeutic agents not only for infections, but also for allergic, autoimmune, and malignant disease.

Simultaneous evaluation of circulating chemokine and cytokine profiles in elderly subjects by multiplex technology: relationship with zinc status

Cellular components of both adaptive and innate immune systems produce different chemokines and cytokines, involved in different signalling pathways among cells, and modulate effector function during immune response, playing a key role in the regulation of the type and extent of the immune response in the elderly. We evaluated the circulating concentration of selected chemokines: MCP-1, MIP-1alpha, IL-8, RANTES together with IL-6 and TNF-alpha in plasma obtained from a group of healthy old subjects, in order to highlight possible differences in the synthesis of these factors, assuming that both the cytokine and the chemokine networks are remodelled with ageing. The simultaneous evaluation was performed by a multiplex analysis system. In addition, since micronutrient deficiency may underlie an inflammatory response, the association between chemokine levels and a nutritional element such as zinc was also evaluated, since the immune system is the first system to be affected by changing zinc levels, due to its high cell turnover. A progressive age-related increase of plasma concentrations of all soluble factors was observed. The increment was particularly evident for IL-6, IL-8, MCP-1 and TNF-alpha in the over 85-year-old group in concomitance with increasing percentages of subjects with low circulating levels of zinc. In conclusion, the remodelling of chemokine profiles, skewed to Th2 response by both advanced ages and circulating levels of zinc, might reflect different states of activation and/or responsiveness of the human immune cell/mediator network, thus influencing the ability to develop rapid innate and long-lasting adaptive immune responses with advancing age.

Inflammation and frailty in older women

OBJECTIVES

To evaluate relationships between white blood cell (WBC) count and interleukin-6 (IL-6) and prevalent frailty.

DESIGN

Cross-sectional study.

SETTING

Two population-based studies, the Women's Health and Aging Studies (WHAS) I and II, Baltimore, Maryland.

PARTICIPANTS

Five hundred fifty-eight women aged 65 to 101 from WHAS I and 548 women aged 70 to 79 from the merged WHAS I and II cohorts.

MEASUREMENTS

Frailty was determined using validated screening criteria. WBC counts and IL-6 levels were measured using standard laboratory methods. Odds ratios (ORs) for frailty were evaluated across tertiles of baseline WBC counts and IL-6 levels, adjusting for age, race, education, body mass index, and smoking status.

RESULTS

In WHAS I, those in the top tertile of WBC count and IL-6 had ORs of 4.25 (95% confidence interval (CI)=1.89-9.58) and 3.98 (95% CI=1.76-9.00), respectively, for frailty (both P<.001). In the combined models, participants in the top tertile of WBC count had an OR of 3.15 (95% CI=1.34-7.41), adjusting for IL-6 (P<.01), and those in the top tertile of IL-6 had an OR of 2.81 (95% CI=1.19-6.64), adjusting for WBC count (P<.05). Furthermore, participants in the top tertiles of WBC count and IL-6 had an OR of 9.85 (95% CI=3.04-31.99), and those in the middle/top tertiles had an OR of 5.40 (95% CI=1.83-15.92) (P<.001, trend test) for frailty. These results were validated in the merged WHAS I and II.

CONCLUSION

Higher WBC counts and IL-6 levels were independently associated with prevalent frailty in community-dwelling older women.

The immunopathogenesis of sepsis in elderly patients

Prominent among the numerous events that contribute to the enhanced susceptibility of elderly patients to infection is the decline of immune function that accompanies aging. Elderly patients experience a marked decline in cell-mediated immune function and reduced humoral immune function. Age-dependent defects in T and B cell function are readily demonstrable in elderly patients, yet the essential elements of innate immunity are remarkably well preserved. The cytokine and chemokine signaling networks are altered in elderly patients and tends to favor a type 2 cytokine response over type 1 cytokine responses. The induction of proinflammatory cytokines after septic stimuli is not adequately controlled by anti-inflammatory mechanisms in elderly persons. This immune dysregulation is accompanied by a more pronounced procoagulant state in older patients. These molecular events function in concert to render elderly patients at excess risk for mortality from severe sepsis and septic shock.

Zinc and Inflammatory/Immune Response in Aging

Life-long antigenic burden determines a condition of chronic inflammation, with increased lymphocyte activation and proinflammatory cytokine production. A large number of studies have documented changes in zinc metabolism in experimental animal models of acute and chronic inflammation and in human chronic inflammatory conditions. In particular, modification of zinc plasma concentration, as well as intracellular disturbance of antioxidant intracellular pathways, has been found in aging and in some age-related diseases. Zinc deficiency is diffused in aged individuals in order to avoid meat and other high zinc content foods due to fear of cholesterol. Rather, they increase the consumption of refined wheat products that lack zinc and other critical nutrients as a consequence of the refining process. On the other hand, plasma zinc concentration is influenced by proinflammatory cytokines (IL-6 and TNF-alpha) and by metallothioneins (MT) homeostasis, which is in turn affected by proinflammatory cytokines. MT increase in aging and chronic inflammation allowing a continuous sequestration of intracellular zinc with subsequent low zinc ion availability against stressor agents and inflammation. This phenomenon leads to an impaired inflammatory/immune response in the elderly. A major target of zinc is NF-kappaB, a transcription factor critical for the expression of proinflammatory cytokines whose production is regulated by extra- and intracellular activating and inhibiting factors interacting with the regulatory elements on cytokine genes. Effects of zinc on translocation of NF-kappaB have been attributed to the suppression of phosphorylation and degradation of the inhibitory proteins (A20) that normally sequester it in the cytoplasm. Moreover, this factor and A20 are regulated by specific genes involved in inflammation and by intracellular zinc ion availability. So, it is not so surprising that zinc deficiency is constantly observed in chronic inflammation, such as in old individuals. On the other hand, cytokine genes are highly polymorphic and some of these polymorphisms are associated with atherosclerosis and diabetes type 2. Therefore, zinc turnover, via MT homeostasis, in individuals genetically predisposed to a dysregulation of the inflammatory/immune response may play a crucial role in causing possible adverse events with the appearance of age-related diseases.

Cytokine-Release Patterns in Elderly Patients with Systemic Inflammatory Response Syndrome

BACKGROUND

Information is scarce about the inflammatory responses to infection in elderly patients.

OBJECTIVE

To investigate the inflammatory pattern in elderly patients with systemic inflammatory response syndrome (SIRS).

METHODS

We assessed the value of pro-inflammatory cytokines (TNF-alpha, IL-6, IL-1beta) and C-reactive protein (CRP) in elderly patients with SIRS at the time of consultation in the emergency room and on the fourth day of hospitalization.

RESULTS

Of 100 patients with SIRS, 92 had a clinical suspicion of infection and 46 were microbiologically confirmed. Basal TNF-alpha and IL-6 levels were higher in patients with bacteremia (p < 0.001 and p = 0.017, respectively). Basal levels of TNF-alpha (p < 0.001) and fourth-day levels of CRP (p = 0.004), TNF-alpha (p < 0.001) and IL-6 (p = 0.002) had a positive correlation with the length of hospitalization. Higher IL-6 levels on the fourth day showed a correlation with mortality (p = 0.016), while the other cytokines and CRP did not show this association.

CONCLUSION

Febrile elderly patients showed an inflammatory response pattern to infection equivalent to that reported in younger patients. Despite some limitations of our study, among febrile elderly patients, pro-inflammatory cytokine levels can be good markers for evaluating the prognosis of infections.

The effect of age on the development and outcome of adult sepsis*

OBJECTIVE

Sepsis is an increasingly common and lethal medical condition that occurs in people of all ages. The influence of age on sepsis risk and outcome is incompletely understood. We sought to determine the independent effect of age on the incidence, severity, and outcome of adult sepsis.

DESIGN

Longitudinal observational study using national hospital discharge data.

SETTING

Approximately 500 geographically separated nonfederal acute care hospitals in the United States.

PATIENTS

Patients were 10,422,301 adult sepsis patients hospitalized over 24 yrs, from 1979 to 2002.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Incident sepsis cases were age adjusted and characterized by demographics, sources and types of infection, comorbid medical conditions, and hospital discharge status. Elderly patients (> or = 65 yrs of age) accounted for 12% of the U.S. population and 64.9% of sepsis cases, yielding a relative risk of 13.1 compared with younger patients (95% confidence interval, 12.6-13.6). Elderly patients were more likely to have Gram-negative infections, particularly in association with pneumonia (relative risk, 1.66; 95% confidence interval, 1.63-1.69) and to have comorbid medical conditions (relative risk, 1.99; 95% confidence interval, 1.92-2.06). Case-fatality rates increased linearly by age; age was an independent predictor of mortality in an adjusted multivariable regression (odds ratio, 2.26; 95% confidence interval, 2.17-2.36). Elderly sepsis patients died earlier during hospitalization, and elderly survivors were more likely to be discharged to a nonacute health care facility.

CONCLUSIONS

The incidence of sepsis is disproportionately increased in elderly adults, and age is an independent predictor of mortality. Compared with younger sepsis patients, elderly nonsurvivors of sepsis die earlier during hospitalization and elderly survivors more frequently require skilled nursing or rehabilitative care after hospitalization. These findings have implications for patient care and health care resource prioritization and provide insights for expanded scientific investigations and potential patient interventions.

Zinc-mediated inhibition of cyclic nucleotide phosphodiesterase activity and expression suppresses TNF-alpha and IL-1 beta production in monocytes by elevation of guanosine 3',5'-cyclic monophosphate

The trace element zinc affects several aspects of immune function, such as the release of proinflammatory cytokines from monocytes. We investigated the role of cyclic nucleotide signaling in zinc inhibition of LPS-induced TNF-alpha and IL-1beta release from primary human monocytes and the monocytic cell line Mono Mac1. Zinc reversibly inhibited enzyme activity of phosphodiesterase-1 (PDE-1), PDE-3, and PDE-4 in cellular lysate. It additionally reduced mRNA expression of PDE-1C, PDE-4A, and PDE-4B in intact cells. Although these PDE can also hydrolyze cAMP, only the cellular level of cGMP was increased after incubation with zinc, whereas cAMP was found to be even slightly reduced due to inhibition of its synthesis. To investigate whether an increase in cGMP alone is sufficient to inhibit cytokine release, the cGMP analogues 8-bromo-cGMP and dibutyryl cGMP as well as the NO donor S-nitrosocysteine were used. All three treatments inhibited TNF-alpha and IL-1beta release after stimulation with LPS. Inhibition of soluble guanylate cyclase-mediated cGMP synthesis with LY83583 reversed the inhibitory effect of zinc on LPS-induced cytokine release. In conclusion, inhibition of PDE by zinc abrogates the LPS-induced release of TNF-alpha and IL-1beta by increasing intracellular cGMP levels.

The inflammatory response to vaccination is altered in the elderly

To further explore whether immune function and acute phase response are altered during ageing, the response to a mild inflammatory stress (DT-Polio-Typhim vaccination) was studied in elderly and young subjects. Cytokine production (IFN-gamma, TNF-alpha, IL-6, IL-10) by whole blood cultures, circulating cytokines and acute phase proteins were analysed before and 2 days after vaccination. Prior to vaccination, only IFN-gamma production was lower in the elderly than in the young subjects due to a lower mononuclear cell number. In the same time, although in the normal range, several acute phase proteins were greater in elderly than in young subjects, suggesting a low-grade inflammatory state in the elderly. After vaccination, IFN-gamma production remained lower in the elderly than in the young, supporting an altered cell-mediated immunity with advancing age. TNF-alpha production was unaffected by either ageing or vaccination. IL-6 production was stimulated by vaccination in young subjects but not significantly in the elderly. IL-10 production was inhibited by vaccination in the elderly but not in the young. Acute phase proteins were less increased in elderly than in young subjects. Taken together, these results support a general lack of inflammatory response in the elderly exposed to an immune challenge and suggest that immune deficiency may concern both Th1 and Th2 responses. However, the interpretation must respect the limitation of small subjects number.

Total and differential white blood cell counts and their associations with circulating interleukin-6 levels in community-dwelling older women

BACKGROUND

Interleukin-6 (IL-6) is an inflammatory biomediator, and age-related increases in IL-6 levels are associated with osteoporosis, sarcopenia, disability, and mortality in older adults. Although white blood cells (WBC), or leukocytes, are known to produce IL-6 in vitro, their in vivo relationship with circulating IL-6 levels is not well established.

METHODS

In this cross-sectional analysis of data from the Women's Health and Aging Study I, the authors evaluated the relationships of total WBC and WBC differential (neutrophil, monocyte, lymphocyte, eosinophil, and basophil) counts to circulating IL-6 levels in 619 community-dwelling older women. Potential associations of age, race, and cigarette smoking with total and differential WBC counts and IL-6 levels were also assessed.

RESULTS

Except for lymphocyte and basophil counts, significant associations of total WBC, neutrophil, monocyte, and eosinophil counts with IL-6 levels were identified. These associations remained highly significant after adjustment for age, race, and smoking status. Total WBC, neutrophil, monocyte, and eosinophil counts had significant stepwise increases in four escalating quartiles of IL-6 levels. In addition, age, race, and cigarette smoking were differentially associated with total and differential WBC counts and IL-6 levels.

CONCLUSIONS

Positive in vivo associations of total WBC and its specific subpopulations were identified, including neutrophils, monocytes, and eosinophils, with circulating IL-6 levels in community-dwelling older women. These findings suggest significant contributions of WBC and its subpopulations to circulating IL-6 levels and potential effects from chronic elevation of IL-6 levels to the function of these circulating immune cells that warrant further investigation.

Stress, glucocorticoids and ageing of the immune system

Ageing has been associated with immunological changes (immunosenescence) that resemble those observed following chronic stress or glucocorticoid (GC) treatment. These changes include thymic involution, lower number of naïve T cells, reduced cell-mediated immunity, and poor vaccination response to new antigens. It follows that immunosenescence could be associated with changes of peripheral GC levels. Indeed, when compared with young subjects, healthy elders are more stressed and show activation of the hypothalamus-pituitary-adrenal (HPA) axis. However, both beneficial and undesirable effects of GCs ultimately depend on the target tissue sensitivity to these steroids. Recent data indicate that peripheral lymphocytes from elders respond poorly to GC treatment in vitro. The present review summarizes recent findings which suggest that immunosenescence may be closely related to both psychological distress and stress hormones. Furthermore, chronically stressed elderly subjects may be particularly at risk of stress-related pathology because of further alterations in GC-immune signalling. Finally, the neuroendocrine hypothesis of immunosenescence is finally reconsidered in which the age-related increase in the cortisol/DHEA ratio is major determinant of immunological changes observed during ageing.

Age-related decline in RACK-1 expression in human leukocytes is correlated to plasma levels of dehydroepiandrosterone

Aging is associated with remodeling of the immune system, contributing to increased incidence of infections, autoimmune diseases, and cancer among the elderly. Alterations in several signal transduction pathways have been reported to play an important role in immunosenescence. We show that peripheral blood leukocytes obtained from old donors (> or =65 years) have a significantly reduced expression of receptor for activated C kinase 1 (RACK-1), a protein required for protein kinase C (PKC)-beta signaling, as compared with young donors (< or =40 years), both in males and females. The decline in RACK-1 immunoboth in reactivity was age-related (Spearman correlation, r=-0.278, P=0.012). All leukocyte subpopulations, namely lympho-monocytes, granulocytes, and B and T cells, showed a similar defect. We also observed a direct correlation between circulating dehydroepiandrosterone (DHEA) and RACK-1 expression in leukocytes (Spearman correlation, r=0.388, P=0.001). Furthermore, in vitro treatment with DHEA resulted in increased RACK-1 expression in leukocytes and lymphocyte proliferation, confirming the role of this hormone in the modulation of its expression and immune functions. A relevant consequence of RACK-1-reduced expression was the observation that release of tumor necrosis factor alpha following lipopolysaccharide challenge and mitogen-induced lymphocye proliferation, which involves PKC-beta activation, was significantly reduced in elderly subjects. Overall, our findings contribute to the understanding of the complex process of immunosenescence and identify age-related loss in immunological responses as partially associated with decreased RACK-1 expression.

Immune monitoring of patients with septic shock by measurement of intraleukocyte cytokines

OBJECTIVE

To assess the immune competence of patients presenting with septic shock by measuring on-line the production of intracellular cytokines by circulating leukocytes.

DESIGN AND SETTING

Prospective study in a 18-bed medical intensive care unit of a university hospital.

PATIENTS AND PARTICIPANTS

21 patients with septic shock, and 11 volunteers.

INTERVENTIONS

Single-step isolation of leukocytes from whole blood obtained within the first 24 h after admission. Leukocytes were fixed immediately or after treatment with lipopolysaccharide (LPS) and/or heterologous plasma.

MEASUREMENTS AND RESULTS

Leukocytes were permeabilized, and the intracellular cytokine expression of TNF-alpha and IL-10 was quantified by immunostaining and flow cytometry. LPS treatment significantly increased monocyte intracellular cytokine TNF-alpha and IL-10 as well as lymphocyte intracellular cytokine IL-10 in normal leukocytes. Septic monocytes and granulocytes had nonstimulated intracellular cytokine TNF-alpha concentrations lower than those measured in volunteers and were severely hyporesponsive to LPS. These phenotypic changes were correlated with disease severity and could be reproduced by treatment of normal leukocytes with plasma from patients with septic shock.

CONCLUSIONS

Intracellular cytokine staining is a simple and rapid method to assess in situ and on-line the inflammatory balance and responsiveness of leukocyte subpopulations and could therefore represent a useful monitoring tool to assess the immune competence of critically ill patients. This study identifies the cellular source of cytokines in whole blood and confirms prior reports showing that septic phagocytes are characterized by a predominant anti-inflammatory phenotype, with hyporesponsiveness to LPS, depending on a plasma deactivation factor.