Ageing and respiratory infections: the airway of ageing

Age-dependent inflammatory response is altered in an ex vivo model of bacterial pneumonia

BACKGROUND

Aging is associated with an increased incidence and mortality of Pseudomonas aeruginosa-induced pneumonias. This might be partly due to age-dependent increases in inflammatory mediators, referred to as inflamm-aging and a decline in immune functions, known as immunosenescence. Still, the impact of dysregulated immune responses on lung infection during aging is poorly understood. Here, we aimed to mimic inflamm-aging using ex vivo precision-cut lung slices (PCLS) and neutrophils - as important effector cells of innate immunity - from young and old mice and investigated the influence of aging on inflammation upon infection with P. aeruginosa bacteria.

METHODS

Murine PCLS were infected with the P. aeruginosa standard lab strain PAO1 and a clinical P. aeruginosa isolate D61. After infection, whole-transcriptome analysis of the tissue as well as cytokine expression in supernatants and tissue lysates were performed. Responses of isolated neutrophils towards the bacteria were investigated by quantifying neutrophil extracellular trap (NET) formation, cytokine secretion, and analyzing expression of surface activation markers using flow cytometry.

RESULTS

Inflamm-aging was observed by transcriptome analysis, showing an enrichment of biological processes related to inflammation, innate immune response, and chemotaxis in uninfected PCLS of old compared with young mice. Upon P. aeruginosa infection, the age-dependent pro-inflammatory response was even further promoted as shown by increased production of cytokines and chemokines such as IL-1β, IL-6, CXCL1, TNF-α, and IL-17A. In neutrophil cultures, aging did not influence NET formation or cytokine secretion during P. aeruginosa infection. However, expression of receptors associated with inflammatory responses such as complement, adhesion, phagocytosis, and degranulation was lower in neutrophils stimulated with bacteria from old mice as compared to young animals.

CONCLUSIONS

By using PCLS and neutrophils from young and old mice as immunocompetent ex vivo test systems, we could mimic dysregulated immune responses upon aging on levels of gene expression, cytokine production, and receptor expression. The results furthermore reflect the exacerbation of inflammation upon P. aeruginosa lung infection as a result of inflamm-aging in old age.

Translational research into frailty from bench to bedside: Salivary biomarkers for inflammaging

Frailty is a complex physiological syndrome associated with adverse ageing and decreased physiological reserves. Frailty leads to cognitive and physical disability and is a significant cause of morbidity, mortality and economic costs. The underlying cause of frailty is multifaceted, including immunosenescence and inflammaging, changes in microbiota and metabolic dysfunction. Currently, salivary biomarkers are used as early predictors for some clinical diseases, contributing to the effective prevention and treatment of diseases, including frailty. Sample collection for salivary analysis is non-invasive and simple, which are paramount factors for testing in the vulnerable frail population. The aim of this review is to describe the current knowledge on the association between frailty and the inflammatory process and discuss methods to identify putative biomarkers in salivary fluids to predict this syndrome. This study describes the relationship between i.-inflammatory process and frailty; ii.-infectious, chronic, skeletal, metabolic and cognitive diseases with inflammation and frailty; iii.-inflammatory biomarkers and salivary fluids. There is a limited number of previous studies focusing on the analysis of inflammatory salivary biomarkers and frailty syndrome; hence, the study of salivary fluids as a source for biomarkers is an open area of research with the potential to address the increasing demands for frailty-associated biomarkers.

Loss of life expectancy due to respiratory infectious diseases: findings from the global burden of disease study in 195 countries and territories 1990-2017

Understanding of the patterns of and changes in mortality from respiratory infectious diseases (RID) and its contribution to loss of life expectancy (LE) is inadequate in the existing literature. With rapid sociodemographic changes globally, and the current COVID-19 pandemic, it is timely to revisit the disease burden of RID. Using the approaches of life table and cause-eliminated life table based on data from the Global Burden of Disease Study (GBD), the study analyses loss of LE due to RID in 195 countries/territories and its changes during the period 1990-2017. Results indicate that loss of LE due to RID stood at 1.29 years globally in 2017 globally and varied widely by age, gender, and geographic location, with men, elderly people, and populations in middle/low income countries/territories suffering a disproportionately high loss of LE due to RID. Additionally, loss of LE due to RID decreased remarkably by 0.97 years globally during the period 1990-2017 but increased slightly among populations older than 70 years and in many high income countries/territories. Results suggest that RID still pose a severe threat for population and public health, and that amid dramatic sociodemographic changes globally, the disease burden of RID may resurge. The study presents the first examination of the life-shortening effect of RID at the global and country/territory levels, providing new understanding of the changing disease burden of RID and shedding light on the potential consequences of the current COVID-19 pandemic.

Rebalancing the unbalanced aged immune system - A special focus on zinc

Nowadays, aging is understood as a dynamic and multifaceted dysregulation process that spares almost no human organ or cell. The immune system being among the most affected, it has been shown predominantly that its integrity determines the tightrope walk between the difference of escaping or suffering from age-related diseases. Next to drug-based anti-aging strategies, micronutrient intervention may represent an emerging but less radical way to slow immune aging. While a sufficient supply of a variety of micronutrients is undeniably important, adequate intake of the trace element zinc appears to tower over others in terms of reaching old age. Inconveniently, zinc deficiency prevalence among the elderly is high, which in turn contributes to increased susceptibility to infection, decreased anti-tumor immunity as well as attenuated response to vaccination. Driven by this research, this review aims to provide a comprehensive and up-to-date overview of the various rebalancing capabilities of zinc in the unbalanced immune system of the elderly. This includes an in-depth and cell type-centered discussion on the role of zinc in immunosenescence and inflammaging. We further address upcoming translational aspects e.g. how zinc deficiency promotes the flourishing of certain pathogenic taxa of the gut microbiome and how zinc supply counteracts such alterations in a manner that may contribute to longevity. In the light of the ongoing COVID-19 pandemic, we also briefly review current knowledge on the interdependency between age, zinc status, and respiratory infections. Based on two concrete examples and considering the latest findings in the field we conclude our remarks by outlining tremendous parallels between suboptimal zinc status and accelerated aging on the one hand and an optimized zinc status and successful aging on the other hand.

Cut-off Points of Treatment Delay to Predict Poor Outcomes Among New Pulmonary Tuberculosis Cases in Dalian, China: A Cohort Study

Purpose

Despite increasing literature on the association between treatment delay and outcomes, cut-off point (1 month or median) selection in almost all studies for treatment delay is too subjective. This study explored more scientific cut-off points of treatment delay for poor treatment outcomes and death at the clinical level.

Patients and Methods

A total of 18,100 newly confirmed pulmonary tuberculosis (TB) cases in Dalian, China were used in the final analysis. A 3-knotted restricted cubic spline (RCS) fitted for Cox proportional hazard regression models is used to analyse the effects of cut-off points of treatment delay on incident poor treatment outcomes. To explore the moderating effects of age, gender and diabetes, we added the interaction terms of these moderating variables and treatment delay to Cox proportional hazard regression models.

Results

The median time of treatment initiation was 30 days (IQR: 14–59 days). The risk of incident poor treatment outcomes increased when the time was greater than cut-off point 1 (53 days; adjusted HR: 1.26; 95% CI: 1.00–1.60) of treatment delay, and the risk of incident death events increased when the time was greater than cut-off point 2 (103 days; adjusted HR: 1.56; 95% CI: 1.00–2.44) of delay. In addition, treatment delay was associated with an increased risk of incident poor treatment outcomes and death, and older age, male sex, and diabetes may increase the risk of treatment delay for poor outcomes.

Conclusion

This study is the first to identify scientific cut-off points of treatment delay for poor treatment outcomes and death, and this method of exploration should be popularized. In addition, the knowledge of tuberculosis must be spread to every adult. Moreover, the tuberculosis diagnosis level of community level health workers should be enhanced.

Marrow failure and aging: The role of "Inflammaging"

Despite aging and the enormous cellular output required of the marrow every day of the lifespan, most aged patients do not suffer significant marrow failure or cytopenias, an attestation to the proliferative capacity of this system. However, as marrow and its hematopoietic stem cells age, a reduction in ability to maintain homeostasis after stress or with exposure to prolonged chronic inflammation, so-called "inflammaging," may contribute to cytopenias, inadequate immune responses, and dysplasia/leukemia. In some instances, these changes may be intrinsic to the stem cell but in others, there may be extrinsic environmental influences. In this review, the role of aging as it relates to stem cell changes, immune function, and anemia are reviewed.

Outcomes of respiratory viral-bacterial co-infection in adult hospitalized patients

BACKGROUND

Viral infections of the respiratory tract represent a major global health concern. Co-infection with bacteria may contribute to severe disease and increased mortality in patients. Nevertheless, viral-bacterial co-infection patterns and their clinical outcomes have not been well characterized to date. This study aimed to evaluate the clinical features and outcomes of patients with viral-bacterial respiratory tract co-infections.

METHODS

We included 19,361 patients with respiratory infection due to respiratory viruses [influenza A and B, respiratory syncytial virus (RSV), parainfluenza] and/or bacteria in four tertiary hospitals in Hong Kong from 2013 to 2017 using a large territory-wide healthcare database. All microbiological tests were conducted within 48 h of hospital admission. Four etiological groups were included: (1) viral infection alone; (2) bacterial infection alone; (3) laboratory-confirmed viral-bacterial co-infection and (4) clinically suspected viral-bacterial co-infection who were tested positive for respiratory virus and negative for bacteria but had received at least four days of antibiotics. Clinical features and outcomes were recorded for laboratory-confirmed viral-bacterial co-infection patients compared to other three groups as control. The primary outcome was 30-day mortality. Secondary outcomes were intensive care unit (ICU) admission and length of hospital stay. Propensity score matching estimated by binary logistic regression was used to adjust for the potential bias that may affect the association between outcomes and covariates.

FINDINGS

Among 15,906 patients with respiratory viral infection, there were 8451 (53.1%) clinically suspected and 1,087 (6.8%) laboratory-confirmed viral-bacterial co-infection. Among all the bacterial species, Haemophilus influenzae (226/1,087, 20.8%), Pseudomonas aeruginosa (180/1087, 16.6%) and Streptococcus pneumoniae (123/1087, 11.3%) were the three most common bacterial pathogens in the laboratory-confirmed co-infection group. Respiratory viruses co-infected with non-pneumococcal streptococci or methicillin-resistant Staphylococcus aureus was associated with the highest death rate [9/30 (30%) and 13/48 (27.1%), respectively] in this cohort. Compared with other infection groups, patients with laboratory-confirmed co-infection had higher ICU admission rate (p < 0.001) and mortality rate at 30 days (p = 0.028), and these results persisted after adjustment for potential confounders using propensity score matching. Furthermore, patients with laboratory-confirmed co-infection had significantly higher mortality compared to patients with bacterial infection alone.

INTERPRETATION

In our cohort, bacterial co-infection is common in hospitalized patients with viral respiratory tract infection and is associated with higher ICU admission rate and mortality. Therefore, active surveillance for bacterial co-infection and early antibiotic treatment may be required to improve outcomes in patients with respiratory viral infection.

Coronavirus-specific antibody production in middle-aged mice requires phospholipase A2G2D

Worse outcomes occur in aged compared with young populations after infections with respiratory viruses, including pathogenic coronaviruses (SARS-CoV, MERS-CoV, and SARS-CoV-2), and are associated with a suboptimal lung milieu ("inflammaging"). We previously showed that a single inducible phospholipase, PLA2G2D, is associated with a proresolving/antiinflammatory response in the lungs, and increases with age. Survival was increased in naive Pla2g2d-/- mice infected with SARS-CoV resulting from augmented respiratory dendritic cell (rDC) activation and enhanced priming of virus-specific T cells. Here, in contrast, we show that intranasal immunization provided no additional protection in middle-aged Pla2g2d-/- mice infected with any of the 3 pathogenic human coronaviruses because virtually no virus-specific antibodies or follicular helper CD4+ T (Tfh) cells were produced. Using MERS-CoV-infected mice, we found that these effects did not result from T or B cell intrinsic factors. Rather, they resulted from enhanced, and ultimately, pathogenic rDC activation, as manifested most prominently by enhanced IL-1β expression. Wild-type rDC transfer to Pla2g2d-/- mice in conjunction with partial IL-1β blockade reversed this defect and resulted in increased virus-specific antibody and Tfh responses. Together, these results indicate that PLA2G2D has an unexpected role in the lungs, serving as an important modulator of rDC activation, with protective and pathogenic effects in respiratory coronavirus infections and immunization, respectively.

Experimental Human Pneumococcal Colonization in Older Adults Is Feasible and Safe, Not Immunogenic

Rationale: Pneumococcal colonization is key to the pathogenesis of invasive disease but is also immunogenic in young adults, protecting against recolonization. Colonization is rarely detected in older adults, despite high rates of pneumococcal disease.Objectives: To establish experimental human pneumococcal colonization in healthy adults aged 50-84 years, to measure the immune response to pneumococcal challenge, and to assess the protective effect of prior colonization against autologous strain rechallenge.Methods: Sixty-four participants were inoculated with Streptococcus pneumoniae (serotype 6B; 80,000 cfu in each nostril). Colonization was determined by bacterial culture of nasal wash, and humoral immune responses were assessed by anticapsular and antiprotein IgG concentrations.Measurements and Main Results: Experimental colonization was established in 39% of participants (25/64) with no adverse events. Colonization occurred in 47% (9/19) of participants aged 50-59 compared with 21% (3/14) in those aged ≥70 years. Previous pneumococcal polysaccharide vaccination did not protect against colonization. Colonization did not confer serotype-specific immune boosting, with a geometric mean titer (95% confidence interval) of 2.7 μg/ml (1.9-3.8) before the challenge versus 3.0 (1.9-4.7) 4 weeks after colonization (P = 0.53). Furthermore, pneumococcal challenge without colonization led to a drop in specific antibody concentrations from 2.8 μg/ml (2.0-3.9) to 2.2 μg/ml (1.6-3.0) after the challenge (P = 0.006). Antiprotein antibody concentrations increased after successful colonization. Rechallenge with the same strain after a median of 8.5 months (interquartile range, 6.7-10.1) led to recolonization in 5/16 (31%).Conclusions: In older adults, experimental pneumococcal colonization is feasible and safe but demonstrates different immunological outcomes compared with younger adults in previous studies.

Outcomes and interventions in the elderly with and without cognitive impairment: a longitudinal study

BACKGROUND

Clinical follow-up studies are necessary for a better understanding of the evolution of cognitive impairment as well as the development of better assessment and intervention tools.

OBJECTIVE

To investigate whether older people with preserved cognition (PC), mild cognitive impairment (MCI) and mild Alzheimer's disease (AD) show differences in clinical outcomes and interventions after a 32-month period.

METHODS

One hundred twenty-four community-dwelling older people were included and classified in one of three groups (PC, MCI and mild AD). Information on clinical outcomes (deaths, new diagnoses, falls, need for assistance or changes in routine and hospitalizations) and interventions (increased use of medication, physiotherapeutic intervention, practice of physical exercise, etc.) in the 32-month period were collected by telephone or during a home visit on a single day.

RESULTS

Ninety-five participants (35 with PC, 33 with MCI and 27 with AD) were reevaluated after 32 months. The need for assistance/changes in routine was significantly higher in the AD group, especially with regard to basic activities of daily living. Unlike the other groups, the PC group did not show "other diagnoses" (urinary incontinence, prolapse, change in vision or autoimmune disease). No significant differences were found regarding other variables.

CONCLUSIONS

Older people with and without cognitive impairment exhibited differences in some clinical outcomes after 32 months, such as need for assistance or changes in their routine and new diagnoses of specific diseases. Therefore, the multidimensionality of geriatric patients should be considered when planning assessments and interventions.

Age-related mitochondrial dysfunction as a key factor in COVID-19 disease

SARS-CoV-2 causes a severe pneumonia (COVID-19) that affects essentially elderly people. In COVID-19, macrophage infiltration into the lung causes a rapid and intense cytokine storm leading finally to a multi-organ failure and death. Comorbidities such as metabolic syndrome, obesity, type 2 diabetes, lung and cardiovascular diseases, all of them age-associated diseases, increase the severity and lethality of COVID-19. Mitochondrial dysfunction is one of the hallmarks of aging and COVID-19 risk factors. Dysfunctional mitochondria is associated with defective immunological response to viral infections and chronic inflammation. This review discuss how mitochondrial dysfunction is associated with defective immune response in aging and different age-related diseases, and with many of the comorbidities associated with poor prognosis in the progression of COVID-19. We suggest here that chronic inflammation caused by mitochondrial dysfunction is responsible of the explosive release of inflammatory cytokines causing severe pneumonia, multi-organ failure and finally death in COVID-19 patients. Preventive treatments based on therapies improving mitochondrial turnover, dynamics and activity would be essential to protect against COVID-19 severity.

Aging induces B cell defects and decreased antibody responses to influenza infection and vaccination

Background

Aging is characterized by a progressive decline in the capacity of the immune system to fight influenza virus infection and to respond to vaccination. Among the several factors involved, in addition to increased frailty and high-risk conditions, the age-associated decrease in cellular and humoral immune responses plays a relevant role. This is in large part due to inflammaging, the chronic low-grade inflammatory status of the elderly, associated with intrinsic inflammation of the immune cells and decreased immune function.

Results

Aging is usually associated with reduced influenza virus-specific and influenza vaccine-specific antibody responses but some elderly individuals with higher pre-exposure antibody titers, due to a previous infection or vaccination, have less probability to get infected. Examples of this exception are the elderly individuals infected during the 2009 pandemic season who made antibodies with broader epitope recognition and higher avidity than those made by younger individuals. Several studies have allowed the identification of B cell intrinsic defects accounting for sub-optimal antibody responses of elderly individuals. These defects include 1) reduced class switch recombination, responsible for the generation of a secondary response of class switched antibodies, 2) reduced de novo somatic hypermutation of the antibody variable region, 3) reduced binding and neutralization capacity, as well as binding specificity, of the secreted antibodies, 4) increased epigenetic modifications that are associated with lower antibody responses, 5) increased frequencies of inflammatory B cell subsets, and 6) shorter telomeres.

Conclusions

Although influenza vaccination represents the most effective way to prevent influenza infection, vaccines with greater immunogenicity are needed to improve the response of elderly individuals. Recent advances in technology have made possible a broad approach to better understand the age-associated changes in immune cells, needed to design tailored vaccines and effective therapeutic strategies that will be able to improve the immune response of vulnerable individuals.

The association between frailty and severe disease among COVID-19 patients aged over 60 years in China: a prospective cohort study

BACKGROUND

The coronavirus disease 2019 (COVID-19) has been a pandemic worldwide. Old age and underlying illnesses are associated with poor prognosis among COVID-19 patients. However, whether frailty, a common geriatric syndrome of reduced reserve to stressors, is associated with poor prognosis among older COVID-19 patients is unknown. The aim of our study is to investigate the association between frailty and severe disease among COVID-19 patients aged ≥ 60 years.

METHODS

A prospective cohort study of 114 hospitalized older patients (≥ 60 years) with confirmed COVID-19 pneumonia was conducted between 7 February 2020 and 6 April 2020. Epidemiological, demographic, clinical, laboratory, and outcome data on admission were extracted from electronic medical records. All patients were assessed for frailty on admission using the FRAIL scale, in which five components are included: fatigue, resistance, ambulation, illnesses, and loss of weight. The outcome was the development of the severe disease within 60 days. We used the Cox proportional hazards models to identify the unadjusted and adjusted associations between frailty and severe illness. The significant variables in univariable analysis were included in the adjusted model.

RESULTS

Of 114 patients, (median age, 67 years; interquartile range = 64-75 years; 57 [50%] men), 39 (34.2%), 39 (34.2%), and 36 (31.6%) were non-frail, pre-frail, and frail, respectively. During the 60 days of follow-up, 43 severe diseases occurred including eight deaths. Four of 39 (10.3%) non-frail patients, 15 of 39 (38.5%) pre-frail patients, and 24 of 36 (66.7%) frail patients progressed to severe disease. After adjustment of age, sex, body mass index, haemoglobin, white blood count, lymphocyte count, albumin, CD8+ count, D-dimer, and C-reactive protein, frailty (HR = 7.47, 95% CI 1.73-32.34, P = 0.007) and pre-frailty (HR = 5.01, 95% CI 1.16-21.61, P = 0.03) were associated with a higher hazard of severe disease than the non-frail.

CONCLUSIONS

Frailty, assessed by the FRAIL scale, was associated with a higher risk of developing severe disease among older COVID-19 patients. Our findings suggested that the use of a clinician friendly assessment of frailty could help in early warning of older patients at high-risk with severe COVID-19 pneumonia.

Allo-priming as a universal anti-viral vaccine: protecting elderly from current COVID-19 and any future unknown viral outbreak

BACKGROUND

We present the rationale for a novel allo-priming approach to serve the elderly as a universal anti-virus vaccine, as well serving to remodel the aging immune system in order to reverse immunosenescence and inflammaging. This approach has the potential to protect the most vulnerable from disease and provide society an incalculable economic benefit. Allo-priming healthy elderly adults is proposed to provide universal protection from progression of any type of viral infection, including protection against progression of the current outbreak of COVID-19 infection, and any future variants of the causative SARS-CoV-2 virus or the next 'Disease X'. Allo-priming is an alternative approach for the COVID-19 pandemic that provides a back-up in case vaccination strategies to elicit neutralizing antibody protection fails or fails to protect the vulnerable elderly population. The allo-priming is performed using activated, intentionally mismatched, ex vivo differentiated and expanded living Th1-like cells (AlloStim^®) derived from healthy donors currently in clinical use as an experimental cancer vaccine. Multiple intradermal injections of AlloStim^® creates a dominate titer of allo-specific Th1/CTL memory cells in circulation, replacing the dominance of exhausted memory cells of the aged immune system. Upon viral encounter, by-stander activation of the allo-specific memory cells causes an immediate release of IFN-ϒ, leading to development of an "anti-viral state", by-stander activation of innate cellular effector cells and activation of cross-reactive allo-specific CTL. In this manner, the non-specific activation of allo-specific Th1/CTL initiates a cascade of spatial and temporal immune events which act to limit the early viral titer. The release of endogenous heat shock proteins (HSP) and DAMP from lysed viral-infected cells, in the context of IFN-ϒ, creates of conditions for in situ vaccination leading to viral-specific Th1/CTL immunity. These viral-specific Th1/CTL provide sterilizing immunity and memory for protection from disease recurrence, while increasing the pool of Th1/CTL in circulation capable of responding to the next viral encounter.

CONCLUSION

Allo-priming has potential to provide universal protection from viral disease and is a strategy to reverse immunosenescence and counter-regulate chronic inflammation (inflammaging). Allo-priming can be used as an adjuvant for anti-viral vaccines and as a counter-measure for unknown biological threats and bio-economic terrorism.

COVID-19: is there a role for immunonutrition, particularly in the over 65s?

In late December 2019 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first emerged in Wuhan, Hubei, China, resulting in the potentially fatal COVID-19. It went on to be officially recognised as a pandemic by the World Health Organisation on 11 March 2020. While many public health strategies have evolved, there has been little mention of the immune system and how this could be strengthened to help protect against viral infections such as SARS-CoV-2. The present paper evaluates the current evidence base relating to immunonutrition, with a particular focus on respiratory viruses. Within the nutrition sector a promising body of evidence studying inter-relationships between certain nutrients and immune competence already exists. This could potentially be an important player in helping the body to deal with the coronavirus, especially among elders. Evidence for vitamins C, D and zinc and their roles in preventing pneumonia and respiratory infections (vitamins C and D) and reinforcing immunity (zinc) appears to look particularly promising. Ongoing research within this important field is urgently needed.

Enhanced Efficacy of Vaccination With Vaccinia Virus in Old vs. Young Mice

Immunosenescence is believed to be responsible for poor vaccine efficacy in the elderly. To overcome this difficulty, research into vaccination strategies and the mechanisms of immune responses to vaccination is required. By analyzing the innate and adaptive immune responses to vaccination with vaccinia virus (VACV) in mice of different age groups, we found that immune cell recruitment, production of cytokines/chemokines and control of viral replication at the site of intradermal vaccination were preserved in aged mice and were comparable with younger groups. Analysis of cervical draining lymph nodes (dLN) collected after vaccination showed that numbers of germinal center B cells and follicular T helper cells were similar across different age groups. The number of VACV-specific CD8 T cells in the spleen and the levels of serum neutralizing antibodies 1 month after vaccination were also comparable across all age groups. However, following intranasal challenge of vaccinated mice, body weight loss was lower and virus was cleared more rapidly in aged mice than in younger animals. In conclusion, vaccination with VACV can induce an effective immune response and stronger protection in elderly animals. Thus, the development of recombinant VACV-based vaccines against different infectious diseases should be considered as a strategy for improving vaccine immunogenicity and efficacy in the elderly.

Immunogenicity and safety of a quadrivalent plant-derived virus like particle influenza vaccine candidate-Two randomized Phase II clinical trials in 18 to 49 and ≥50 years old adults

Background

New influenza vaccines eliciting more effective protection are needed, particularly for the elderly who paid a large and disproportional toll of hospitalization and dead during seasonal influenza epidemics. Low (≤15 μg/strain) doses of a new plant-derived virus-like-particle (VLP) vaccine candidate have been shown to induce humoral and cellular responses against both homologous and heterologous strains in healthy adults 18–64 years of age. The two clinical trials reported here addressed the safety and immunogenicity of higher doses (≥15 μg/strain) of quadrivalent VLP candidate vaccine on 18–49 years old and ≥50 years old subjects. We also investigated the impact of alum on the immunogenicity induced by lower doses of the vaccine candidate.

Method

In the first Phase II trial reported here (NCT02233816), 18–49 year old subjects received 15, 30 or 60 μg/strain of a hemagglutinin-bearing quadrivalent virus-like particle (QVLP) vaccine or placebo. In the second trial (NCT02236052), ≥50 years old subjects received QVLP as above or placebo with additional groups receiving 7.5 or 15 μg/strain with alum. Along with safety recording, the humoral and cell-mediated immune responses were analyzed.

Results

Local and systemic side-effects were similar to those reported previously. The QVLP vaccine induced significant homologous and heterologous antibody responses at the two higher doses, the addition of alum having little-to-no effect. Serologic outcomes tended to be lower in ≥50 years old subjects previously vaccinated. The candidate vaccine also consistently elicited both homologous and heterologous antigen-specific CD4⁺ T cells characterized by their production of interferon-gamma (IFN-γ), interleukine-2 (IL-2) and/or tumor-necrosis factor alpha (TNF-α) upon ex vivo antigenic restimulation.

Conclusion

Overall, the 30 μg dose produced the most consistent humoral and cellular responses in both 18–49 and ≥50 years old subjects, strongly supporting the clinical development of this candidate vaccine. That particular dose was chosen to test in the ongoing Phase III clinical trial.

Comparison of a frailty short interview to a validated frailty index in adults hospitalized for acute respiratory illness

BACKGROUND

Frailty is an important physiologic factor in studies of influenza and influenza vaccines carried out in older adults and hospitalized populations. Unfortunately, comprehensive assessments of frailty requiring physical assessments and extensive medical record review are not often feasible in time- and resource-limited settings common to studies of influenza and influenza vaccines.

METHODS

We developed a 5-question frailty short interview, and implemented it in a multicenter, hospital-based study of influenza over two years. Frailty status defined by the frailty short interview was compared to a validated frailty index based on medical record review of 59 parameters. Agreement between the two frailty measures was assessed, and multivariable linear regression models were used to explore differences between the measures. The association between each frailty measure and likelihood of influenza vaccination was also assessed.

RESULTS

During the 2015-2016 and 2016-2017 influenza seasons, 2070 adult patients hospitalized with acute respiratory illness were enrolled and included in analyses. Frailty was frequently identified in the study population; 43% of participants were defined as frail by the frailty short interview and 32% by frailty index. Responses to the frailty short interview were only moderately correlated with the frailty index, and agreement between the two frailty measures was low. Women were more likely to be defined as frail by the frailty short interview than men. White individuals were more likely than other races to be defined as frail by the frailty index. Increasing frailty index was associated with increased likelihood of influenza vaccination, but the frailty short interview was not associated with vaccination.

CONCLUSIONS

The frailty short interview provided a feasible and consistent measure of frailty across study hospitals and study years. However, its modest correlation with the frailty index and differential association with likelihood of influenza vaccination highlight differences in the conceptualization of frailty.

Cohort profile: the China Ageing REespiratory infections Study (CARES), a prospective cohort study in older adults in Eastern China

PURPOSE

This study was established to provide direct evidence on the incidence of laboratory-confirmed influenza virus and respiratory syncytial virus (RSV) infections in older adults in two cities in Jiangsu Province, China, and the potential impact of acute respiratory infections on frailty.

PARTICIPANTS

The cohort was enrolled in Suzhou and Yancheng, two cities in Jiangsu Province in Eastern China. Between November 2015 and March 2016, we enrolled 1532 adults who were 60-89 years of age, and collected blood samples along with baseline data on demographics, general health, chronic diseases, functional status and cognitive function through face-to-face interviews using a standardised questionnaire. Participants are being followed weekly throughout the year to identify acute respiratory illnesses. We schedule home visits to ill participants to collect mid-turbinate nasal and oropharyngeal swabs for laboratory testing and detailed symptom information for the acute illness. Regular follow-up including face-to-face interviews and further blood draws will take place every 6-12 months.

FINDINGS TO DATE

As of 3 September 2016, we had identified 339 qualifying acute respiratory illness events and 1463 (95%) participants remained in the study. Laboratory testing is ongoing.

FUTURE PLANS

We plan to conduct laboratory testing to estimate the incidence of influenza virus and RSV infections in older adults. We plan to investigate the impact of these infections on frailty and functional status to determine the association of pre-existing immune status with protection against influenza and RSV infection in unvaccinated older adults, and to assess the exposure to avian influenza viruses in this population.

Reevaluation of immune activation in the era of cART and an aging HIV-infected population

Biological aging is associated with immune activation (IA) and declining immunity due to systemic inflammation. It is widely accepted that HIV infection causes persistent IA and premature immune senescence despite effective antiretroviral therapy and virologic suppression; however, the effects of combined HIV infection and aging are not well defined. Here, we assessed the relationship between markers of IA and inflammation during biological aging in HIV-infected and -uninfected populations. Antibody response to seasonal influenza vaccination was implemented as a measure of immune competence and relationships between IA, inflammation, and antibody responses were explored using statistical modeling appropriate for integrating high-dimensional data sets. Our results show that markers of IA, such as coexpression of HLA antigen D related (HLA-DR) and CD38 on CD4+ T cells, exhibit strong associations with HIV infection but not with biological age. Certain variables that showed a strong relationship with aging, such as declining naive and CD38+ CD4 and CD8+ T cells, did so regardless of HIV infection. Interestingly, the variable of biological age was not identified in a predictive model as significantly impacting vaccine responses in either group, while distinct IA and inflammatory variables were closely associated with vaccine response in HIV-infected and -uninfected populations. These findings shed light on the most relevant and persistent immune defects during virological suppression with antiretroviral therapy.

Treatment delay and fatal outcomes of pulmonary tuberculosis in advanced age: a retrospective nationwide cohort study

BACKGROUND AND OBJECTIVE

Studies focusing on pulmonary tuberculosis in advanced age (≥80 years) are lacking. This study aimed to explore treatment delay, outcomes and their predictors in this group.

METHODS

Adult (≥20 years) patients with pulmonary tuberculosis were identified from the National Health Insurance Research Database of Taiwan from 2004 to 2009. Treatment completion and mortality rates were noted at one year after treatment.

RESULTS

Among the 81,081 patients with pulmonary tuberculosis identified, 13,923 (17.2%) were aged ≥80 years, and 26,897 (33.2%) were aged 65-79 years. The treatment completion, mortality rates and treatment delay were 54.8%, 34.7% and 61 (12-128) [median, (1st-3rd quartiles)] days in patients aged ≥80 years, 68.3%, 18.5% and 53 (8-122) days in patients aged 65-79 years, and 78.9%, 6.5% and 21 (1-84) days in patients aged <65 years, respectively. The elder patients were more likely to receive second-line anti-tuberculosis agents. The treatment completion rate decreased with older age, female sex, comorbidities, low income, requiring second-line anti-tuberculosis agents, severity of pulmonary tuberculosis and longer treatment delay. Older age, female sex, comorbidities, low income, and not undergoing rapid molecular diagnostic tests were independently associated with longer treatment delays.

CONCLUSIONS

Pulmonary tuberculosis in advanced age has a longer treatment delay and a higher mortality rate. Applying rapid molecular diagnostic tools may reduce treatment delay and should be integrated into the diagnostic algorithm for pulmonary tuberculosis, particularly in elderly patients.

Pneumococcal Capsular Polysaccharide Immunity in the Elderly

Immunity to pneumococcal infections is impaired in older people, and current vaccines are poorly protective against pneumococcal disease in this population. Naturally acquired immunity to pneumococcal capsular polysaccharides develops during childhood and is robust in young adults but deteriorates with advanced age. In particular, antibody levels and function are reduced in older people. Pneumococcal vaccines are recommended for people >65 years old. However, the benefits of polysaccharide and protein-conjugated vaccines in this population are small, because of both serotype replacement and incomplete protection against vaccine serotype pneumococcal disease. In this review, we overview the immune mechanisms by which naturally acquired and vaccine-induced pneumococcal capsular polysaccharide immunity declines with age, including altered colonization dynamics, reduced opsonic activity of antibodies (particularly IgM), and impaired mucosal immunity.

Inflamm-Aging of Hematopoiesis, Hematopoietic Stem Cells, and the Bone Marrow Microenvironment

All hematopoietic and immune cells are continuously generated by hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) through highly organized process of stepwise lineage commitment. In the steady state, HSCs are mostly quiescent, while HPCs are actively proliferating and contributing to daily hematopoiesis. In response to hematopoietic challenges, e.g., life-threatening blood loss, infection, and inflammation, HSCs can be activated to proliferate and engage in blood formation. The HSC activation induced by hematopoietic demand is mediated by direct or indirect sensing mechanisms involving pattern recognition receptors or cytokine/chemokine receptors. In contrast to the hematopoietic challenges with obvious clinical symptoms, how the aging process, which involves low-grade chronic inflammation, impacts hematopoiesis remains undefined. Herein, we summarize recent findings pertaining to functional alternations of hematopoiesis, HSCs, and the bone marrow (BM) microenvironment during the processes of aging and inflammation and highlight some common cellular and molecular changes during the processes that influence hematopoiesis and its cells of origin, HSCs and HPCs, as well as the BM microenvironment. We also discuss how age-dependent alterations of the immune system lead to subclinical inflammatory states and how inflammatory signaling might be involved in hematopoietic aging. Our aim is to present evidence supporting the concept of “Inflamm-Aging,” or inflammation-associated aging of hematopoiesis.

T-Cell Immunity to Influenza in Older Adults: A Pathophysiological Framework for Development of More Effective Vaccines

One of the most profound public health consequences of immune senescence is reflected in an increased susceptibility to influenza and other acute respiratory illnesses, as well as a loss of influenza vaccine effectiveness in older people. Common medical conditions and mental and psychosocial health issues as well as degree of frailty and functional dependence accelerate changes associated with immune senescence. All contribute to the increased risk for complications of influenza infection, including pneumonias, heart diseases, and strokes that lead to hospitalization, disability, and death in the over 65 population. Changes in mucosal barrier mechanisms and both innate and adaptive immune functions converge in the reduced response to influenza infection, and lead to a loss of antibody-mediated protection against influenza with age. The interactions of immune senescence and reduced adaptive immune responses, persistent cytomegalovirus infection, inflammaging (chronic elevation of inflammatory cytokines), and dysregulated cytokine production, pose major challenges to the development of vaccines designed to improve T-cell-mediated immunity. In older adults, the goal of vaccination is more realistically targeted to providing clinical protection against disease rather than to inducing sterilizing immunity to infection. Standard assays of antibody titers correlate with protection against influenza illness but do not detect important changes in cellular immune mechanisms that correlate with vaccine-mediated protection against influenza in older people. This article will discuss: (i) the burden of influenza in older adults and how this relates to changes in T-cell function, (ii) age-related changes in different T-cell subsets and immunologic targets for improved influenza vaccine efficacy in older, and (iii) the development of correlates of clinical protection against influenza disease to expedite the process of new vaccine development for the 65 and older population. Ultimately, these efforts will address the public health need for improved protection against influenza in older adults and “vaccine preventable disability.”

COPD is characterized by increased detection of Haemophilus influenzae, Streptococcus pneumoniae and a deficiency of Bacillus species

BACKGROUND AND OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and inflammation. Airway bacterial colonization is increased in COPD; however, the role of potentially pathogenic and non-pathogenic bacteria in the pathogenesis of disease is unclear. This study characterized the presence of bacteria in a well-characterized cohort of adults with COPD and healthy controls.

METHODS

Adults with COPD (n = 70) and healthy controls (n = 51) underwent clinical assessment and sputum induction. Sputum was dispersed, and total and differential cell counts were performed. Bacteria were cultured, identified and enumerated. Supernatants were assessed for neutrophil elastase (NE) and IL-1β. Common respiratory pathogens were also determined using real-time PCR.

RESULTS

Participants with COPD had a typical neutrophilic inflammatory profile. The total load of bacteria was increased in COPD and was associated with poorer respiratory health status, as measured by the St George's Respiratory Questionnaire (Spearman's r = 0.336, P = 0.013). Significantly lower levels of culturable Bacillus species were identified compared with healthy controls. PCR analyses revealed increased rates of detection of potentially pathogenic bacteria with Haemophilus influenzae detection associated with higher sputum levels of NE and IL-1β, while Streptococcus pneumoniae was more common in male ex-smokers with emphysema and a deficit in diffusion capacity.

CONCLUSION

Non-pathogenic and pathogenic bacteria were altered in the sputum of patients with COPD. These observations highlight the potential to identify treatment and management strategies that both target specific bacterial pathogens and restore the microbial balance, which may lead to reductions in inflammation and subsequent improvements in lung health.

DAMPs and influenza virus infection in ageing

Influenza A virus (IAV) is a serious global health problem worldwide due to frequent and severe outbreaks. IAV causes significant morbidity and mortality in the elderly population, due to the ineffectiveness of the vaccine and the alteration of T cell immunity with ageing. The cellular and molecular link between ageing and virus infection is unclear and it is possible that damage associated molecular patterns (DAMPs) may play a role in the raised severity and susceptibility of virus infections in the elderly. DAMPs which are released from damaged cells following activation, injury or cell death can activate the immune response through the stimulation of the inflammasome through several types of receptors found on the plasma membrane, inside endosomes after endocytosis as well as in the cytosol. In this review, the detriment in the immune system during ageing and the links between influenza virus infection and ageing will be discussed. In addition, the role of DAMPs such as HMGB1 and S100/Annexin in ageing, and the enhanced morbidity and mortality to severe influenza infection in ageing will be highlighted.