The aging immune system: challenges for the 21st century

Immunosuppressive therapy in elderly patients with neuromyelitis optica spectrum disorder: a retrospective multicentre study

BACKGROUND

The risk-benefit relationship of immunosuppressive therapies (ISTs) for elderly patients with neuromyelitis optica spectrum disorder (NMOSD) is not well established. This study aimed to investigate the safety and efficacy of IST in elderly patients with NMOSD.

METHODS

This retrospective study analysed IST efficacy and safety in 101 patients with aquaporin-4 antibody-positive NMOSD aged over 65 years, treated for at least 6 months at five Korean referral centres, focusing on relapse rates, infection events and discontinuation due to adverse outcomes.

RESULTS

The mean age at disease onset was 59.8 years, and female-to-male ratio was 4:1. Concomitant comorbidities at NMOSD diagnosis were found in 87 patients (86%). The median Expanded Disability Status Scale score at the initiation of IST was 3.5. The administered ISTs included azathioprine (n=61, 60%), mycophenolate mofetil (MMF) (n=48, 48%) and rituximab (n=41, 41%). Over a median of 5.8 years of IST, 58% of patients were relapse-free. The median annualised relapse rate decreased from 0.76 to 0 (p<0.001), and 81% experienced improved or stabilised disability. Patients treated with rituximab had a higher relapse-free rate than those treated with azathioprine or MMF (p=0.022). During IST, 21 patients experienced 25 severe infection events (SIEs) over the age of 65 years, and 3 died from pneumonia. 14 patients (14%) experienced 17 adverse events that led to switching or discontinuation of IST. When comparing the incidence rates of SIEs and adverse events, no differences were observed among patients receiving azathioprine, MMF and rituximab.

CONCLUSION

In elderly patients with NMOSD, IST offers potential benefits in reducing relapse rates alongside a tolerable risk of adverse events.

Impact of aging on immunity in the context of COVID-19, HIV, and tuberculosis

Knowledge of aging biology needs to be expanded due to the continuously growing number of elderly people worldwide. Aging induces changes that affect all systems of the body. The risk of cardiovascular disease and cancer increases with age. In particular, the age-induced adaptation of the immune system causes a greater susceptibility to infections and contributes to the inability to control pathogen growth and immune-mediated tissue damage. Since the impact of aging on immune function, is still to be fully elucidated, this review addresses some of the recent understanding of age-related changes affecting key components of immunity. The emphasis is on immunosenescence and inflammaging that are impacted by common infectious diseases that are characterized by a high mortality, and includes COVID-19, HIV and tuberculosis.

Age-associated alterations in immune function and inflammation

Immunosenescence is a term used to describe the age-related changes in the immune system. Immunosenescence is associated with complex alterations and dysregulation of immune function and inflammatory processes. Age-related changes in innate immune responses including alterations in chemotactic, phagocytic, and natural killing functions, impaired antigen presenting capacity, and dysregulated inflammatory response have been described. The most striking and best characterized feature of immunosenescence is the decline in both number and function of T cells. With age there is decreased proliferation, decreased number of antigen-naïve T cells, and increased number of antigen-experienced memory T cells. This decline in naïve T cell population is associated with impaired immunity and reduced response to new or mutated pathogens. While the absolute number of peripheral B cells appears constant with age, changes in B cell functions including reduced antibody production and response and cell memory have been described. However, the main alteration in cell-mediated function that has been reported across all species with aging is those observed in in T cell. These T cell mediated changes have been shown to contribute to increased susceptibility to infection and cancer in older adults. In addition to functional and phenotype alterations in immune cells, studies demonstrate that circulating concentrations of inflammatory mediators in older adults are higher than those of young. This low grade, chronic inflammatory state that occurs in the context of aging has been termed "inflammaging". This review will focus on age-related changes in the immune system including immunosenescence and inflammation as well as the functional consequences of these age-related alterations for the aged.

Clinical characteristics and outcomes in hospitalized adult influenza patients: an observational study from Norway 2014-2018

BACKGROUND

Seasonal influenza causes substantial numbers of hospitalizations annually. We have characterized the clinical picture and treatment practice in hospitalized adult influenza patients and assessed whether clinical risk scores on admission or influenza type were associated with severe outcomes.

METHODS

Clinical characteristics and risk scores on admission (CRB65, CRB, SIRS and quick Sequential Organ Failure Assessment [qSOFA]), treatment and severe outcomes (defined as: stay in intensive care unit (ICU), receiving oxygen supplementation or staying ≥5 days in hospital), were recorded in patients hospitalized with influenza at Oslo University Hospital, Norway, between 2014 and 2018.

RESULTS

Among the 156 included patients, 52.6% had influenza A(H3N2), 32.6% influenza B and 12.8% influenza A(H1N1). Median age was 70 years and 59.6% of patients were ≥65 years. Nine (5.8%) of the patients were treated in ICU, 43.0% received oxygen and 47.4% stayed ≥5 days in hospital. Overall, 34.6% of the patients had a high CRB score on admission which was associated with stay in ICU and oxygen supplementation. Multivariate analyses identified age, and pneumonia (46.8%), but not influenza type, to be associated with severe outcomes. Antiviral treatment was given to 37.2% of the patients, while 77.6% received antibiotics. Only 25.5% of patients with influenza B received antiviral therapy.

CONCLUSIONS

The influenza patients were mostly elderly, and few patients were treated in ICU. A high CRB score was associated with severe outcomes with possible implications for patient monitoring. Less than 40% of the patients received antiviral therapy, whereas the majority were treated with antibiotics, indicating potential for optimising treatment strategies.

Non-small cell lung cancer: Emerging molecular targeted and immunotherapeutic agents

Non-small cell lung cancer (NSCLC) represents the most common and fatal type of primary lung malignancies. NSCLC is often diagnosed at later stages and requires systemic therapies. Despite recent advances in surgery, chemotherapy, and targeted molecular therapies the outcomes of NSCLC remain disproportionately poor. Immunotherapy is a rapidly developing area in NSCLC management and presents opportunities for potential improvements in clinical outcomes. Indeed, different immunotherapeutics have been approved for clinical use in various settings for NSCLC. Their promise is especially poignant in light of improved survival and quality of life outcomes. Herein, we comprehensively review emerging NSCLC therapeutics. We discuss the limitations of such strategies and summarize the present status of various immunotherapeutic agents in key patient populations. We also examine the data from ongoing studies in immunotherapy and consider future areas of study, including novel inhibition targets, therapeutic vaccination, tumor genome modification, and improvements to drug delivery systems.

Physical, Emotional, Medical, and Socioeconomic Status of Patients With NMOSD: A Cross-Sectional Survey of 123 Cases From a Single Center in North China

Objective: This study aimed to assess the physical, emotional, medical, and socioeconomic conditions of patients with neuromyelitis optica spectrum disorder (NMOSD) in North China.

Methods: A cross-sectional survey of patients with NMOSD was performed, based on an established questionnaire from the Multiple Sclerosis Patient Survival Report 2018. Logistic regression analysis was conducted to define the significant determinants of certain physical or emotional characteristics of patients. A total of 123 patients were included.

Results: A total of 63.4% of participants were initially diagnosed with conditions other than NMOSD, with a median delay of 6 months for accurate diagnosis. An aggregate of 72.2% of patients had one or more relapses, corresponding to an annual relapse rate of 0.8. Paresthesia was the most frequent physical symptom among patients both at disease onset (53.7%) and throughout the duration of the disease (86.2%). Onset in elderly (>50 years) patients was associated with an annual Expanded Disability Status Scale increase ≥1, compared with onset in younger (<30 years) patients (P = 0.001, OR = 7.83). A total of 76.4% of patients had received attack-prevention treatments in the remission phase, and 31.7 and 10.6% of patients had ever been administered rituximab and traditional Chinese medicine, respectively. Additionally, 63.4 and 43.1% of patients reported participating in few or no social activities and being out of work because of the disease. To be noted, 76.4% of patients reported suffering from negative emotions, with the most frequent being worry (60.2%), with 20.3% of patients experiencing suicidal thoughts. The inability to work and participating in few or no social activities due to NMOSD were two determinants of experiencing negative emotions (P_work = 0.03, OR_work = 3.34; P_{socialactivities} = 0.02, OR_{socialactivities} = 3.19).

Conclusion: This study reported patient perspectives on NMOSD in North China, whereby demonstrating that the inability to work and participating in few or no social activities due to NMOSD rather than the physical impairment caused by the disease, was directly associated with patients experiencing negative emotions. This insight offers potential ways to manage patients' negative emotions by enhancing family and social support and facilitating active employment.

Network Topology of Biological Aging and Geroscience-Guided Approaches to COVID-19

Aging has emerged as the greatest and most prevalent risk factor for the development of severe COVID-19 infection and death following exposure to the SARS-CoV-2 virus. The presence of multiple co-existing chronic diseases and conditions of aging further enhances this risk. Biological aging not only enhances the risk of chronic diseases, but the presence of such conditions further accelerates varied biological processes or "hallmarks" implicated in aging. Given growing evidence that it is possible to slow the rate of many biological aging processes using pharmacological compounds has led to the proposal that such geroscience-guided interventions may help enhance immune resilience and improve outcomes in the face of SARS-CoV-2 infection. Our review of the literature indicates that most, if not all, hallmarks of aging may contribute to the enhanced COVID-19 vulnerability seen in frail older adults. Moreover, varied biological mechanisms implicated in aging do not function in isolation from each other, and exhibit intricate effects on each other. With all of these considerations in mind, we highlight limitations of current strategies mostly focused on individual single mechanisms, and we propose an approach which is far more multidisciplinary and systems-based emphasizing network topology of biological aging and geroscience-guided approaches to COVID-19.

Innate Immune Cells and Their Contribution to T-Cell-Based Immunotherapy

In recent years, immunotherapy has become the most promising therapy for a variety of cancer types. The development of immune checkpoint blockade (ICB) therapies, the adoptive transfer of tumor-specific T cells (adoptive cell therapy (ACT)) or the generation of T cells engineered with chimeric antigen receptors (CAR) have been successfully applied to elicit durable immunological responses in cancer patients. However, not all the patients respond to these therapies, leaving a consistent gap of therapeutic improvement that still needs to be filled. The innate immune components of the tumor microenvironment play a pivotal role in the activation and modulation of the adaptive immune response against the tumor. Indeed, several efforts are made to develop strategies aimed to harness innate immune cells in the context of cancer immunotherapy. In this review, we describe the contribution of innate immune cells in T-cell-based cancer immunotherapy and the therapeutic approaches implemented to broaden the efficacy of these therapies in cancer patients.

Perspective: Should Vitamin E Recommendations for Older Adults Be Increased?

Current vitamin E requirements are uniformly applied across the population for those >14 y of age. However, aging is associated with alterations in cellular and physiologic functions, which are affected by vitamin E. Therefore, it is questionable whether vitamin E requirements can be uniformly applied to all adult age categories. With aging, there is dysregulation of the immune system in which there are decreased cell-mediated and pathogen defense responses coupled with an overactive, prolonged inflammatory state. Both animal and human studies in the aged suggest that intake above currently recommended levels of vitamin E may improve immune and inflammatory responses and be associated with a reduced risk of infectious disease. We review the evidence that was considered in establishing the current requirements for vitamin E and highlight data that should be considered in determining the vitamin E requirements in older adults, particularly focusing on the evidence suggesting a benefit of increased vitamin E intake on immune function and inflammatory processes and resistance to infection. The main objective of this Perspective is to initiate the discussion of whether the current Dietary Reference Intake for vitamin E should be increased for the older population. We make this suggestion on the basis of mechanistic studies showing biological plausibility, correction of a major cellular dysfunction in older adults, and strong evidence from several animal and a few human studies indicating a reduction in risk and morbidity from infections.

Treatment of advanced non-small cell lung cancer in the elderly

INTRODUCTION

Lung cancer is predominantly a disease that affects the elderly; about 30-40% of lung cancers are diagnosed in patients aged 70 or more. The increasing number of elderly patients over the next decades is generating a new social and health problem; despite that, these patients are underrepresented in clinical trials and undertreated in clinical practice. Areas covered: The main difficulty in treating elderly patients is to maximize the therapy benefits while minimizing the treatment risk. Elderly patients show a vulnerable clinical profile due to the higher prevalence of comorbid disease, higher polypharmacy interactions and aged organ dysfunction that increase the risk of mortality and toxicity with cancer treatments compared to younger patients. Expert commentary: The choice to treat or not to treat elderly patients cannot be taken only on the basis of the chronological age. Thus, the clinical approach should be to select patients who are effectively suitable for treatment having a better individual functional reserve and a better life expectancy. Elderly patients are a heterogeneous population and those who are fit to receive cancer treatment can be treated similarly to younger patients.

Aging and the immune system: An overview

The world is witnessing a rapid demographic shift towards an older population, a trend with major medical, social, economic and political implications. Aging is a multifaceted process, involving numerous molecular and cellular mechanisms in the context of different organ systems. A crucial component of aging is a set of functional and structural alterations in the immune system that can manifest as a decreased ability to fight infection, diminished response to vaccination, increased incidence of cancer, higher prevalence of autoimmunity and constitutive low-grade inflammation, among others. In addition to cell-intrinsic changes in both innate and adaptive immune cells, alterations in the stromal microenvironment in primary and secondary lymphoid organs play an important role in age-associated immune dysfunction. This article will provide a broad overview of these phenomena and point out some of their clinical and therapeutic implications.

Osteosarcopenic obesity and its relationship with dyslipidemia in women from different ethnic groups of China

OBJECTIVES

To explore the prevalence and ethnic differences of osteosarcopenic obesity (OSO) and dyslipidemia and their relationship among Maonan, Mulam, Hmong, and Yao minorities in China.

METHODS

A total of 2315 Maonan, Mulam, Hmong, and Yao women aged 20-95 from Guangxi were included in this study. Questionnaire survey was carried out and their blood lipids were tested. Body compositions were measured by bioelectrical impedance analysis, and T-score was assessed by ultrasonic examination, respectively.

RESULTS

Our study showed ethnic-specific prevalence of OSO. In older women, the incidence rates of OSO in Mulam were 4.9, 12.6, and 11.5% in Maonan, Mulam, and Hmong ethnicity, respectively. In younger group, the incidence rates of OSO were 0.4, 0.4, and 0.6%, respectively. However, there is no prevalence of OSO in Yao women in two groups. The prevalence of dyslipidemia in younger women was 22.86, 29.89, 43.35, and 80.00% in group numbering one, two, and three, respectively. In older women, it was 29.13, 39.02, 41.37, and 52.38%, respectively. Based on logistic regression analysis, after controlling for covariates, dyslipidemia in younger group was positively associated with a higher number of adverse body composition, especially for OSO (OR = 12.53, 95%CI 1.34-116.99). Compared with normal women, OSO women in older group were also more likely to have dyslipidemia (OR = 6.75, 95%CI 3.19-14.31).

CONCLUSION

OSO may be a risk factor for dyslipidemia in the ethnic groups. Thus, efforts to promote healthy aging should be focused on preventing obesity and maintaining bone health and muscle mass.

Late-onset neuromyelitis optica spectrum disorder in AQP4-seropositivepatients in a Chinese population

Background

Increasing rates of AQP4-seropositive neuromyelitis optica spectrum disorder (NMOSD) have been reported in late-onset patients (LONMOSD). However, the full range of clinical differences between early-onset and late-onset variants remain unclear. We describe the clinical features and outcomes of AQP4-seropositive LONMOSD patients in a Chinese population.

Methods

This was a retrospective analysis of medical records in a cohort study of AQP4-seropositive NMOSD patients with early-onset (≤49 years) and late-onset (≥50 years) variants between January 2006 and February 2014. Demographic, clinical, neuroimaging and cerebrospinal fluid (CSF) findings and prognosis data were analyzed.

Results

We identified thirty AQP4-seropositive LONMOSD patients (86.7 % women). The median age at onset was 57.5 years (range 50–70). There were similar onset frequencies between optic neuritis (ON) and longitudinally extensive transverse myelitis (LETM). Longer interval between (first) ON and LETM (median 13 vs. 4 months; p < 0.05), time from first symptoms to diagnosis of NMO (median 17 vs. 7 months, p < 0.05), higher comorbidities (66.7 vs. 26.7 %; p < 0.05), and more hypertension (26.7 vs.3.3 %; p < 0.05) were prevalent. NMO-like lesions were less common (10.7 vs. 41.6 %; p < 0.05), while the rate of non-specific lesions tended to be higher (53.6 vs. 29 %; p = 0.067). These patients displayed more severe Expanded Disability Status Scale (EDSS) in nadir (median 6.75vs.5; p < 0.05). Attacks often resulted in EDSS 4 within a short period (median 8 vs. 13.5 months; p < 0.05). At last follow-up, the EDSS score was more severe in these patients (median 5.25 vs. 4; p < 0.05). No significant predictors were identified.

Conclusions

This study provides an overview of the clinical and paraclinical features of AQP4-seropositive LONMOSD patients in China and demonstrates a number of distinct disease characteristics in early vs. late onset. Older patients are more susceptible to disability in short course. However, these patients do not always display NMO-like lesions in the brain. Initial LETM may not necessarily be predominant as the initial symptom, contrary to previous reports. The higher comorbidities may warrant a modified approach of treatment.

Intrinsic TGF-β signaling promotes age-dependent CD8+ T cell polyfunctionality attrition

Advanced age is associated with immune system deficits that result in an increased susceptibility to infectious diseases; however, specific mediators of age-dependent immune dysfunction have not been fully elucidated. Here we demonstrated that aged mice exhibit poor effector CD8+ T cell polyfunctionality, primarily due to CD8+ T cell-extrinsic deficits, and that reduced CD8+ T cell polyfunctionality correlates with increased susceptibility to pathogenic diseases. In aged animals challenged with the parasite Encephalitozoon cuniculi, effector CD8+ T cell survival and polyfunctionality were suppressed by highly elevated TGF-β1. Furthermore, TGF-β depletion reduced effector CD8+ T cell apoptosis in both young and aged mice and enhanced effector CD8+ T cell polyfunctionality in aged mice. Surprisingly, intrinsic blockade of TGF-β signaling in CD8+ T cells was sufficient to rescue polyfunctionality in aged animals. Together, these data demonstrate that low levels of TGF-β1 promote apoptosis of CD8+ effector T cells and high TGF-β1 levels associated with age result in both CD8+ T cell apoptosis and an altered transcriptional profile, which correlates with loss of polyfunctionality. Furthermore, elevated TGF-β levels are observed in the elderly human population and in aged Drosophila, suggesting that TGF-β represents an evolutionarily conserved negative regulator of the immune response in aging organisms.

Effects of aging on influenza virus infection dynamics

The consequences of influenza virus infection are generally more severe in individuals over 65 years of age (the elderly). Immunosenescence enhances the susceptibility to viral infections and renders vaccination less effective. Understanding age-related changes in the immune system is crucial in order to design prophylactic and immunomodulatory strategies to reduce morbidity and mortality in the elderly. Here, we propose different mathematical models to provide a quantitative understanding of the immune strategies in the course of influenza virus infection using experimental data from young and aged mice. Simulation results suggested a central role of CD8(+) T cells for adequate viral clearance kinetics in young and aged mice. Adding the removal of infected cells by natural killer cells did not improve the model fit in either young or aged animals. We separately examined the infection-resistant state of cells promoted by the cytokines alpha/beta interferon (IFN-α/β), IFN-γ, and tumor necrosis factor alpha (TNF-α). The combination of activated CD8(+) T cells with any of the cytokines provided the best fits in young and aged animals. During the first 3 days after infection, the basic reproductive number for aged mice was 1.5-fold lower than that for young mice (P < 0.05).

IMPORTANCE

The fits of our models to the experimental data suggest that the increased levels of IFN-α/β, IFN-γ, and TNF-α (the "inflammaging" state) promote slower viral growth in aged mice, which consequently limits the stimulation of immune cells and contributes to the reported impaired responses in the elderly. A quantitative understanding of influenza virus pathogenesis and its shift in the elderly is the key contribution of this work.

CD4 T cell defects in the aged: causes, consequences and strategies to circumvent

Aging leads to reduced immunity, especially adaptive responses. A key deficiency is the poor ability to mount robust antibody response. Although intrinsic alterations in B cells with age are in part responsible, impaired CD4 T cell help makes a major contribution to the poor antibody response. Other CD4 effector responses and memory generation are also impaired. We find delayed and reduced development of CD4 T follicular help (Tfh) cells in aged mice in response to influenza infection with reduction of long-lived plasma cells. When we examine CD4 subsets we also find a shift towards Th1 and cytotoxic CD4 (ThCTL) responses. We summarize strategies to circumvent the CD4 T cell defect in aged, including adjuvants and proinflammatory cytokines. We find that we can strongly enhance responses of aged naïve CD4 T cells by using Toll-like receptor (TLR) activated dendritic cells (DC) as APC in vivo and that this leads to improved germinal center B cells and IgG antibody responses. The enhanced response of aged naïve CD4 T cells is dependent on IL-6 produced by the DC.