Immunologic Function in the Elderly After Injury—The Neutrophil and Innate Immunity

A Nomogram to Better Predict the In-Hospital Mortality of Trauma Patients with Sepsis in the Intensive Care Unit

BACKGROUND

Trauma has a high incidence and mortality worldwide, and sepsis is one of the main causes of mortality in trauma patients. Therefore, it is essential to identify the risk factors of in-hospital mortality for trauma patients with sepsis.

METHODS

Data were extracted from the Medical Information Mart for Intensive Care III database and divided into a training set and internal validation set, and another Chinese dataset was used as external validation set. Then, risk factors were estimated using univariate and multivariate logistic regression analyses in the training set. Finally, a nomogram was created to predict the probability of in-hospital mortality for trauma patients with sepsis.

RESULTS

A total of 503 patients were enrolled in our study (335 in the training set and 168 in the validation set). Multivariate logistic regression analysis revealed that age (1.047 [1.025-1.071]), respiratory rate (1.258 [1.135-1.394]), PTT (1.026 [1.008-1.044]), ventilation (6.703 [1.528-29.408]), and vasopressor use (3.682 [1.502-9.025]) were independent factors associated with in-hospital mortality. The nomogram for trauma-related sepsis predicted in-hospital mortality with AUC values of 0.8939 in the training set, 0.8200 in the internal validation set, and 0.7779 in the external validation set.

CONCLUSIONS

The new nomogram has a well predicted value for in-hospital mortality for patients with trauma and sepsis in intensive care units.

Hyporesponsiveness of natural killer cells and impaired inflammatory responses in critically ill patients

Background

To investigate natural killer (NK) cell activity, circulating cytokine level and peripheral blood mononuclear cell (PBMC) cytokine production status in critically ill patients.

Methods

Blood samples were collected <24 h after admission from 24 intensive care unit (ICU) patients and 24 age-, sex-, and body mass index (BMI)-matched healthy controls. Serum cytokine concentrations and cytokine production by PBMCs and lipopolysaccharide (LPS)-stimulated PBMCs were measured.

Results

The ICU group showed lower NK cell activity than the controls under all conditions and an absence of interferon (IFN)-γ. After adjusting for triglycerides, LDL- and HDL-cholesterol, and glucose, the ICU group exhibited lower serum levels of albumin and interleukin (IL)-12 and higher leukocyte counts and hs-CRP and IL-6 levels than the controls. Non-stimulated PBMCs from ICU patients secreted significantly greater amounts of IL-6 and IL-1β than the controls; however, the production of IL-6, TNF-α and IL-1β in response to LPS stimulation was significantly lower in the ICU group.

Conclusions

Significant reductions in NK cell activity and serum IL-12 level, an absence of serum IFN-γ, and decreased cytokine production from LPS-stimulated PBMCs indicate the hyporesponsiveness of NK cells and an impaired early phase inflammatory response in critically ill patients (ClinicalTrials.gov NCT02565589:). Retrospectively registered; October 1, 2015.

The geriatric cytokine response to trauma: time to consider a new threshold

BACKGROUND

Inflammatory responses to trauma, especially if exaggerated, drive mortality and morbidities including infectious complications. Geriatric patients are particularly susceptible to profound inflammation. Age-related declines in inflammatory and immune systems are known to occur. Geriatric patients display dampened inflammatory responses to non-critical disease processes. Specific inflammatory responses in critically ill geriatric trauma patients, and how the inflammatory profile associated with subsequent infections or mortality, remain unknown.

METHODS

Geriatric (≥65 y) and young (18-50 y old) critically ill blunt trauma intensive care unit (ICU) patients were enrolled prospectively. Blood was drawn within 36 h of presentation to measure circulating cytokines including interleukin (IL)-6 (pg/mL), IL-10 (pg/mL), and tumor necrosis factor (TNF)-α (pg/mL) levels. Age, gender, Acute Physiology and Chronic Health Evaluation (APACHE II) score and outcomes were reviewed.

RESULTS

Twenty-one young and 29 geriatric critically ill patients were recruited. Groups were comparable in male gender and age-adjusted APACHE II score, but geriatric patients had higher mortality (38% versus 9.5%; p=0.04). Within geriatric trauma patients, the development of a secondary infection was associated with significantly lower presenting IL-6 and IL-10 levels and no difference in TNF-α levels. Furthermore, geriatric patients who died had elevated IL-6 and IL-10 and decreased TNF-α levels compared with geriatric patients who lived. Compared with the young cohort, IL-6 and IL-10 levels were similar between geriatric patients who died and young patients who lived. However, geriatric patients who lived, compared with young patients who lived, had significantly lower IL-6 and IL-10. There was no such relation noted with TNF-α.

CONCLUSIONS

A lowered inflammatory response in geriatric patients is associated with the development of a subsequent infection. However, geriatric patients exhibiting inflammatory responses as robust as their younger counterparts have increased mortality. Redefining our understanding of an appropriate geriatric inflammatory response to trauma will help future therapy, thereby improving morbidity and mortality.

Impact of age on the clinical outcomes of major trauma

PURPOSE

In view of demographic changes over the past few decades, the average age of trauma patients is progressively increasing. We therefore aimed to summarize the specific characteristics of geriatric trauma and to identify potential fields for further research to improve the care of elderly trauma patients.

METHODS

Review of the literature.

RESULTS

Due to the diverse risk factors (e.g., pre-existing conditions, limited physiological reserve), geriatric patients are prone to developing severe complications, even after less severe trauma. Yet, age is not considered as the only predictor of worse outcomes, and it should not be considered the only criterion for limiting care in those patients. It is crucial that age-specific treatment guidelines are developed to optimize the outcomes for senior trauma patients. Based on the current literature, these guidelines should emphasize the importance of field triage directly to a trauma center, along with the activation of the trauma team. Furthermore, early intensive monitoring, aggressive resuscitation, and time of surgical intervention are of upmost importance to reduce mortality.

CONCLUSION

The impact of several factors [age, premedical conditions (PMC), decreased physiological reserves, and impaired immune function] on the post-traumatic course of elderly trauma patients needs to be clarified in future experimental and clinical studies for the early identification of geriatric high-risk patients and for the development of age-adapted therapeutic strategies.

Risk factors for sepsis in Korean trauma patients

PURPOSE

Sepsis in severely injured patients is one of the leading causes of death in hospitals. The incidence of and risk factors for sepsis after trauma have been studied outside, but not within Korea. Therefore, this study investigated the incidence of sepsis and the independent risk factors for sepsis in moderately to severely injured patients in Korea.

METHODS

The electronic medical records of patients who visited the emergency department from January 2010 to December 2012 were reviewed retrospectively. Patients older than 18 years of age with an Injury Severity Score (ISS) greater than or equal to nine points were included.

RESULTS

A total of 183 patients met the study inclusion criteria. The median ISS was 14 (range 9-17) points and 15 (8 %) patients developed sepsis. The patients' age [adjusted OR, 1.053; 95 % confidence intervals (CI), 1.015-1.094], ISS (adjusted OR, 1.114; 95 % CI, 1.046-1.187), and emergency surgery (adjusted OR, 3.727; 95 % CI, 1.051-13.221) were independent risk factors for post-traumatic sepsis.

CONCLUSIONS

Among the risk factors identified in the literature, our research confirmed only the patients' age and ISS as risk factors for sepsis after trauma, and, additionally, identified emergency surgery as a risk factor in Korean patients. Therefore, trauma patients who have any of the risk factors mentioned above have a high risk of post-traumatic sepsis, which requires certain precautionary clinical measures.

Probiotics for preventing acute upper respiratory tract infections

BACKGROUND

Probiotics may improve a person's health by regulating their immune function. Some trials have shown that probiotic strains can prevent respiratory infections. Even though the previous version of our review showed benefits of probiotics for acute upper respiratory tract infections (URTIs), several new studies have been published.

OBJECTIVES

To assess the effectiveness and safety of probiotics (any specified strain or dose), compared with placebo, in the prevention of acute URTIs in people of all ages, at risk of acute URTIs.

SEARCH METHODS

We searched CENTRAL (2014, Issue 6), MEDLINE (1950 to July week 3, 2014), EMBASE (1974 to July 2014), Web of Science (1900 to July 2014), the Chinese Biomedical Literature Database, which includes the China Biological Medicine Database (from 1978 to July 2014), the Chinese Medicine Popular Science Literature Database (from 2000 to July 2014) and the Masters Degree Dissertation of Beijing Union Medical College Database (from 1981 to July 2014). We also searched the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov for completed and ongoing trials on 31 July 2014.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing probiotics with placebo to prevent acute URTIs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility and quality of trials, and extracted data using the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included 13 RCTs, although we could only extract data to meta-analyse 12 trials, which involved 3720 participants including children, adults (aged around 40 years) and older people. We found that probiotics were better than placebo when measuring the number of participants experiencing episodes of acute URTI (at least one episode: odds ratio (OR) 0.53; 95% confidence interval (CI) 0.37 to 0.76, P value < 0.001, low quality evidence; at least three episodes: OR 0.53; 95% CI 0.36 to 0.80, P value = 0.002, low quality evidence); the mean duration of an episode of acute URTI (mean difference (MD) -1.89; 95% CI -2.03 to -1.75, P value < 0.001, low quality evidence); reduced antibiotic prescription rates for acute URTIs (OR 0.65; 95% CI 0.45 to 0.94, moderate quality evidence) and cold-related school absence (OR 0.10; 95% CI 0.02 to 0.47, very low quality evidence). Probiotics and placebo were similar when measuring the rate ratio of episodes of acute URTI (rate ratio 0.83; 95% CI 0.66 to 1.05, P value = 0.12, very low quality evidence) and adverse events (OR 0.88; 95% CI 0.65 to 1.19, P value = 0.40, low quality evidence). Side effects of probiotics were minor and gastrointestinal symptoms were the most common. We found that some subgroups had a high level of heterogeneity when we conducted pooled analyses and the evidence level was low or very low quality.

AUTHORS' CONCLUSIONS

Probiotics were better than placebo in reducing the number of participants experiencing episodes of acute URTI, the mean duration of an episode of acute URTI, antibiotic use and cold-related school absence. This indicates that probiotics may be more beneficial than placebo for preventing acute URTIs. However, the quality of the evidence was low or very low.

Uncontrolled sepsis: a systematic review of translational immunology studies in intensive care medicine

BACKGROUND

The design of clinical immunology studies in sepsis presents several fundamental challenges to improving the translational understanding of pathologic mechanisms. We undertook a systematic review of bed-to-benchside studies to test the hypothesis that variable clinical design methodologies used to investigate immunologic function in sepsis contribute to apparently conflicting laboratory data, and identify potential alternatives that overcome various obstacles to improve experimental design.

METHODS

We performed a systematic review of the design methodology employed to study neutrophil function (respiratory burst), monocyte endotoxin tolerance and lymphocyte apoptosis in the intensive care setting, over the past 15 years. We specifically focussed on how control samples were defined, taking into account age, gender, ethnicity, concomitant therapies, timing of sample collection and the criteria used to diagnose sepsis.

RESULTS

We identified 57 eligible studies, the majority of which (74%) used case-control methodology. Healthy volunteers represented the control population selected in 83% of studies. Comprehensive demographic data on age, gender and ethnicity were provided in ≤48% of case control studies. Documentation of diseases associated with immunosuppression, malignancy and immunomodulatory therapies was rare. Less than half (44%) of studies undertook independent adjudication for the diagnosis of sepsis while 68% provided microbiological data. The timing of sample collection was defined by highly variable clinical criteria. By contrast, surgical studies avoided many such confounders, although only one study in surgical patients monitored the study group for development of sepsis.

CONCLUSIONS

We found several important and common limitations in the clinical design of translational immunologic studies in human sepsis. Major elective surgery overcame many of these methodological limitations. The failure of adequate clinical design in mechanistic studies may contribute to the lack of translational therapeutic progress in intensive care medicine.

Multiplexed measurements of immunomodulator levels in peripheral blood of healthy subjects: Effects of analytical variables based on anticoagulants, age, and gender

Multiplex microbead immunoassay (MMIA) is a powerful technology for a wide range of biomedical and clinical applications. It is important to study the normal concentration ranges of immunomodulators under different sample preparation conditions and age groups of subjects in order to more precisely determine their reference values for use in assessing alterations of their levels in disease. The aim of this study was to determine the plasma concentrations of immunomodulators (cytokines, chemokines, and growth factors) in the peripheral blood from healthy subjects by the use of a large multiplex panel, and to determine the effects of different anticoagulants, age, and gender on the immunomodulator levels. In addition, the assay precision for these biomarker analytes was determined. Plasma samples from 107 healthy subjects, aged 18 to 85 years, were collected in three different anticoagulants (sodium citrate, EDTA, Heparin); corresponding serum samples were also obtained. Multiplex microbead immunoassays were performed for measuring a total of 23 analytes including chemokines, cytokines, and growth factors (IL-1β, IL-1ra, IL-2, IL-6, IL-7, IL-8, IL-12 p70, IL-17, IFN-γ, IP-10, MCP-1, PDGF-BB, RANTES, TNF-α, IL-1a, IL-16, HGF, MIG, TNF-β, PDGF-ABBB, EGF, Flt-3 Ligand, VEGF). For these analytes, our results showed that the anticoagulant affected the concentration measurements and the coefficients of variation. However, the relative levels of the analytes (profiles) of samples collected in a particular anticoagulant are consistent. The analytes IL-1β, IL-7, Flt-3 Ligand, and IL-12p70 show the largest variation (up to fourfold) between the age groups. In addition, no statistically significant differences in the level of the analytes were found between the sexes.

A divergent response of innate regulatory T-cells to sepsis in humans: circulating invariant natural killer T-cells are preserved

BACKGROUND

Sepsis is associated with severe immunosuppression, evidenced by loss and dysfunction of CD3(+) lymphocytes and γδ-TCR(+) T-cells. There is limited data addressing changes in the invariant natural killer T-(iNKT) cell population with sepsis, and whether such changes correlate with clinical outcomes. Specifically, septic geriatric patients have marked mortality. How γδ-TCR(+) T-cells and iNKT-cells are altered in the settings of sepsis and advanced age, and how these changes correlate with mortality are unknown.

METHODS

49 young (18-50years) and 55 geriatric (>65years) ICU patients with confirmed sepsis were enrolled. Blood was stained with antibodies to detect the percentage and absolute number of CD3(+) (T-cells), γδ-TCR(+) T-cell, TCR-Vα-24(+) (iNKT-cells), and CD69(+) (marker of cell activation). Blood from 10 healthy controls was also collected.

RESULTS

Septic patients displayed marked leukocytosis, decreased CD3(+) lymphocytes, and γδ-TCR(+) T-cells, and increased percentage and number of iNKT-cells. Young and geriatric patients had similar degree of leukocytosis, along with percentage, number, and %CD69(+) CD3(+) T-cell and γδ-TCR(+) T-cells; however, percentage, number, and %CD69(+)iNKT-cells were most markedly elevated in geriatric patients. Geriatric non-survivors had higher percentage and number of, but decreased %CD69(+), iNKT-cells vs survivors.

CONCLUSIONS

iNKT-cells are increased in sepsis, suggesting that they typify an evolving morbid state. This is most pronounced in geriatric non-survivors, a group demonstrating dysfunctional regulatory iNKT-cell phenotype.

Neutrophil heterogeneity in health and disease: a revitalized avenue in inflammation and immunity

Leucocytes form the principal cellular components of immunity and inflammation, existing as multiple subsets defined by distinct phenotypic and functional profiles. To date, this has most notably been documented for lymphocytes and monocytes. In contrast, as neutrophils are traditionally considered, to be short-lived, terminally differentiated cells that do not re-circulate, the potential existence of distinct neutrophil subsets with functional and phenotypic heterogeneity has not been widely considered or explored. A growing body of evidence is now challenging this scenario, and there is significant evidence for the existence of different neutrophil subsets under both physiological and pathological conditions. This review will summarize the key findings that have triggered a renewed interest in neutrophil phenotypic changes, both in terms of functional implications and consequences within disease models. Special emphasis will be placed on the potential pro- and anti-inflammatory roles of neutrophil subsets, as indicated by the recent works in models of ischaemia–reperfusion injury, trauma, cancer and sepsis.

Predictors of sepsis in moderately severely injured patients: an analysis of the National Trauma Data Bank

BACKGROUND

Post-traumatic sepsis is a significant cause of in-hospital death. However, socio-demographic and clinical characteristics that may predict sepsis in injured patients are not well known. The objective of this study was to identify risk factors that may be associated with post-traumatic sepsis.

METHODS

Retrospective analysis of patients in the National Trauma Data Bank for 2007-2008. Patients older than 16 years of age with an Injury Severity Score (ISS) ≥ 9 points were included. Multivariable logistic regression was used to determine association of sepsis with patient (age, gender, ethnicity, and insurance status), injury (mechanism, ISS, injury type, hypotension), and clinical (major surgical procedure, intensive care unit admission) characteristics.

RESULTS

Of a total of 1.3 million patients, 373,370 met the study criteria, and 1.4% developed sepsis, with an associated mortality rate of approximately 20%. Age, male gender, African-American race, hypotension on emergency department presentation, and motor vehicle crash as the injury mechanism were independently associated with post-traumatic sepsis.

CONCLUSIONS

Socio-demographic and injury factors, such as age, race, hypotension on admission, and severity and mechanism of injury predict post-traumatic sepsis significantly. Further exploration to explain why these patient groups are at increased risk is warranted in order to understand better and potentially prevent this life-threatening complication.

High-energy skeletal trauma in the elderly

Despite the increasing prevalence of high-energy skeletal trauma in the elderly (i.e., sixty years or older), there is a lack of prospective data regarding best care for these injuries.Elderly patients with multiple injuries are often undertriaged to trauma centers and underresuscitated.Aggressive early resuscitation can improve outcomes in elderly patients who have sustained skeletal trauma.Comanagement by orthopaedic surgeons and geriatricians of elderly patients with skeletal trauma can lead to a lower length of hospital stay, lower readmission rates, shorter time to operation, lower complication rates, and lower mortality.

Unique pattern of complications in elderly trauma patients at a Level I trauma center

BACKGROUND

Trauma centers are caring for increased proportions of elderly patients. Although age and Injury Severity Score are independently associated with mortality, trauma centers were originally designed to care for seriously injured patients without age-specific guidelines. We hypothesized that elderly patients would have different complication patterns than their younger counterparts.

METHODS

The trauma registry of an American College of Surgeons -verified Level I trauma center was queried for all patients older than 14 years admitted between January 2005 and December 2008. Mechanism, mortality, and complications were evaluated after dividing patients into eight age groups.

RESULTS

Of the 15,223 patients, 13% were elderly (≥65), and 86% were injured via a blunt mechanism. Increasing age correlated with fatality (all Injury Severity Scores), end-organ failure, and thromboembolic complications (deep venous thrombosis and coagulopathy). Analysis revealed a significant breakpoint at 45 years of age for mortality, decubitus ulcer, and renal failure (all p values <0.05). Infectious complications (sepsis, wound infection, and abscess) all peaked between 45 years and 65 years and then declined with increasing age.

CONCLUSIONS

We document that elderly trauma patients suffer the same complications as their younger counterparts, albeit at a different rate. More importantly, we identified a "breakpoint" of increased risk of complications and mortality at greater than 45 years. Although the mechanisms behind these observations remain unknown, understanding their unique patterns may allow appropriate allocation of resources and focus research efforts on interventions that should improve outcomes.

Blunt thoracic injury in older adults: application of Haddon's phase-factor matrix model

Blunt thoracic injury (BTI) in older adults can lead to grave illness, permanent disability, and even death. Using Haddon's phase-factor matrix model, this article examines the phenomenon of BTI in older adults. Preventive, diagnostic, and treatment interventions are discussed from the perspective of the pre-event, event, and post-event phases. Relevant physiological and pathophysiological changes regarding senescence and injury are reviewed, as are the common mechanisms of blunt trauma and anatomic injury patterns seen in older adults. Considerations for clinical interventions and future research are also presented.

Diurnal variation in mortality in older nocturnal fallers

BACKGROUND

The prevalence of older trauma patients is rising in Westernised populations. Age has an independent adverse affect on survival from injury. Factors contributing to this increased mortality are incompletely understood.

OBJECTIVE

To examine the independent effects of age, time and mechanism of injury on survival from trauma at 30 days.

METHODS

We analysed prospectively collected data from the Trauma Audit and Research Network database. Isolated femoral neck and pubic rami fractures are not included in this data set. Univariate and multivariate regression analyses were undertaken. Independent effects of age, time of injury and mechanism of injury on survival following trauma were evaluated.

RESULTS

A total of 137,521 trauma patients were included in the study. Trauma victims aged over 65 years had increased odds of death of 9.58 (95% CI: 8.78-10.45), adjusting for known confounders of outcome. Analysis of two-way interactions of age and time of arrival to hospital, revealed patients ≥65 years had a higher odds of death if they presented between midnight and 8 a.m., compared with 08:00-16:00 h; OR = 1.5, (95% CI: 1.29-1.73). Further analysis of this older group, examining the interaction of time and mechanism of injury, revealed a doubling of the odds of death in patients injured following a fall <2 m, when they presented between midnight and 8 a.m.; OR = 2.1, (95% CI: 1.32-3.30). This diurnal variation in mortality was exclusive to older fallers.

CONCLUSIONS

Age over 65 years has an independent detrimental affect on survival from trauma. A distinct diurnal variation in mortality from injury occurs in older patients injured as a result of a low velocity fall.

Probiotics for preventing acute upper respiratory tract infections

BACKGROUND

Probiotics may improve a person's health by regulating their immune function. Some studies show that probiotic strains can prevent respiratory infections. However, no evidence of the benefits of probiotics for acute upper respiratory tract infections (URTIs) and related potential adverse effects has been published.

OBJECTIVES

To assess the effectiveness and safety of probiotics for preventing acute URTIs.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 2), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (Ovid) (1950 to May week 1, 2011), EMBASE (1974 to May 2011), Web of Science which includes Science Citation Index (from 1900 to May 2011) and Conference Proceedings Citation Index (from 1991 to May 2011), the Chinese Biomedical Literature Database, which includes the China Biological Medicine Database (from 1978 to May 2011), the Chinese Medicine Popular Science Literature Database (from 2000 to May 2011) and the Masters Degree Dissertation of Beijing Union Medical College Database (from 1981 to May 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing probiotics with placebo to prevent acute URTIs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility, quality of trials and extracted data.

MAIN RESULTS

We included 14 RCTs, although we could only extract available data to meta-analyse in 10 trials which involved 3451 participants. We found that probiotics were better than placebo when measuring the number of participants experiencing episodes of acute URTI: at least one episode: odds ratio (OR) 0.58; 95% confidence interval (CI) 0.36 to 0.92; at least three episodes: OR 0.53; 95% CI 0.36 to 0.80; rate ratio of episodes of acute URTI: rate ratio 0.88; 95% CI 0.81 to 0.96; and reduced antibiotic prescription rates for acute URTIs: OR 0.67; 95% CI 0.45 to 0.98. Probiotics and placebo were similar when measuring the mean duration (MD) of an episode of acute URTI: MD -0.29; 95% CI -3.71 to 3.13 and adverse events: OR 0.92; 95% CI 0.37 to 2.28. Side effects of probiotics were minor and gastrointestinal symptoms were the most common. We found that some subgroups had a high level of heterogeneity when conducting pooled analyses.

AUTHORS' CONCLUSIONS

Probiotics were better than placebo in reducing the number of participants experiencing episodes of acute URTIs, the rate ratio of episodes of acute URTI and reducing antibiotic use. This indicates that probiotics may be more beneficial than placebo for preventing acute URTIs. However, the results have some limitations and there were no data for older people.

Aging-dependent changes of microglial cells and their relevance for neurodegenerative disorders

Among multiple structural and functional brain changes, aging is accompanied by an increase of inflammatory signaling in the nervous system as well as a dysfunction of the immune system elsewhere. Although the long-held view that aging involves neurocognitive impairment is now dismissed, aging is a major risk factor for neurodegenerative diseases such as Alzheimer;s disease, Parkinson;s disease and Huntington's disease, among others. There are many age-related changes affecting the brain, contributing both to certain declining in function and increased frailty, which could singly and collectively affect neuronal viability and vulnerability. Among those changes, both inflammatory responses in aged brains and the altered regulation of toll like receptors, which appears to be relevant for understanding susceptibility to neurodegenerative processes, are linked to pathogenic mechanisms of several diseases. Here, we review how aging and pro-inflammatory environment could modulate microglial phenotype and its reactivity and contribute to the genesis of neurodegenerative processes. Data support our idea that age-related microglial cell changes, by inducing cytotoxicity in contrast to neuroprotection, could contribute to the onset of neurodegenerative changes. This view can have important implications for the development of new therapeutic approaches.