The aging bone marrow and its impact on immune responses in old age

Obesity, bone marrow adiposity, and leukemia: Time to act

Obesity has taken the face of a pandemic with less direct concern among the general population and scientific community. However, obesity is considered a low-grade systemic inflammation that impacts multiple organs. Chronic inflammation is also associated with different solid and blood cancers. In addition, emerging evidence demonstrates that individuals with obesity are at higher risk of developing blood cancers and have poorer clinical outcomes than individuals in a normal weight range. The bone marrow is critical for hematopoiesis, lymphopoiesis, and myelopoiesis. Therefore, it is vital to understand the mechanisms by which obesity-associated changes in BM adiposity impact leukemia development. BM adipocytes are critical to maintain homeostasis via different means, including immune regulation. However, obesity increases BM adiposity and creates a pro-inflammatory environment to upregulate clonal hematopoiesis and a leukemia-supportive environment. Obesity further alters lymphopoiesis and myelopoiesis via different mechanisms, which dysregulate myeloid and lymphoid immune cell functions mentioned in the text under different sequentially discussed sections. The altered immune cell function during obesity alters hematological malignancies and leukemia susceptibility. Therefore, obesity-induced altered BM adiposity, immune cell generation, and function impact an individual's predisposition and severity of leukemia, which should be considered a critical factor in leukemia patients.

Multicenter evaluation of the addition of eltrombopag to immunosuppressive therapy for adults with severe aplastic anemia

Eltrombopag has been shown to improve response rates when added to standard therapy in adults with severe aplastic anemia in controlled trial settings. However, outcomes in real-world populations have mostly been examined in small retrospective studies. This robust, multicenter, retrospective cohort study across six academic health systems compared outcomes in patients who received immunosuppressive therapy with or without eltrombopag. The study included 82 patients who received front-line therapy from January 2014 to August 2021. Overall response rates at 6 months did not differ significantly for patients receiving eltrombopag versus immunosuppressive therapy alone (58% v. 65%, p = 0.56). However, complete response rates at 6 and 12 months were over two times higher in the eltrombopag arm (29% v. 12%, p = 0.06 and 48% v. 18%, p = 0.005). Rates of hepatotoxicity were similar across both arms. Eltrombopag addition did not impact overall survival (median not reached in either arm at 2 years, p = 0.86) or disease-free survival (median not reached v. 13.3 months at 2 years, p = 0.20). Eltrombopag may not produce as large of a benefit in real-world settings compared to controlled trial settings but may offer patients deeper responses with similar rates of toxicity to immunosuppressive therapy alone.

Severe CD8+ T Lymphopenia in WHIM Syndrome Caused by Selective Sequestration in Primary Immune Organs

Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome is an ultra-rare combined primary immunodeficiency disease caused by heterozygous gain-of-function mutations in the chemokine receptor CXCR4. WHIM patients typically present with recurrent acute infections associated with myelokathexis (severe neutropenia due to bone marrow retention of mature neutrophils). Severe lymphopenia is also common, but the only associated chronic opportunistic pathogen is human papillomavirus and mechanisms are not clearly defined. In this study, we show that WHIM mutations cause more severe CD8 than CD4 lymphopenia in WHIM patients and WHIM model mice. Mechanistic studies in mice revealed selective and WHIM allele dose-dependent accumulation of mature CD8 single-positive cells in thymus in a cell-intrinsic manner due to prolonged intrathymic residence, associated with increased CD8 single-positive thymocyte chemotactic responses in vitro toward the CXCR4 ligand CXCL12. In addition, mature WHIM CD8+ T cells preferentially home to and are retained in the bone marrow in mice in a cell-intrinsic manner. Administration of the specific CXCR4 antagonist AMD3100 (plerixafor) in mice rapidly and transiently corrected T cell lymphopenia and the CD4/CD8 ratio. After lymphocytic choriomeningitis virus infection, we found no difference in memory CD8+ T cell differentiation or viral load between wild-type and WHIM model mice. Thus, lymphopenia in WHIM syndrome may involve severe CXCR4-dependent CD8+ T cell deficiency resulting in part from sequestration in the primary lymphoid organs, thymus, and bone marrow.

Inflammation and aging: signaling pathways and intervention therapies

Aging is characterized by systemic chronic inflammation, which is accompanied by cellular senescence, immunosenescence, organ dysfunction, and age-related diseases. Given the multidimensional complexity of aging, there is an urgent need for a systematic organization of inflammaging through dimensionality reduction. Factors secreted by senescent cells, known as the senescence-associated secretory phenotype (SASP), promote chronic inflammation and can induce senescence in normal cells. At the same time, chronic inflammation accelerates the senescence of immune cells, resulting in weakened immune function and an inability to clear senescent cells and inflammatory factors, which creates a vicious cycle of inflammation and senescence. Persistently elevated inflammation levels in organs such as the bone marrow, liver, and lungs cannot be eliminated in time, leading to organ damage and aging-related diseases. Therefore, inflammation has been recognized as an endogenous factor in aging, and the elimination of inflammation could be a potential strategy for anti-aging. Here we discuss inflammaging at the molecular, cellular, organ, and disease levels, and review current aging models, the implications of cutting-edge single cell technologies, as well as anti-aging strategies. Since preventing and alleviating aging-related diseases and improving the overall quality of life are the ultimate goals of aging research, our review highlights the critical features and potential mechanisms of inflammation and aging, along with the latest developments and future directions in aging research, providing a theoretical foundation for novel and practical anti-aging strategies.

Physical exercise program to older frail patients receiving chemotherapy for colorectal cancer - feasibility and experiences from the GERICO study

INTRODUCTION

Older and frail patients with cancer are at high risk of physical and functional decline during chemotherapy. Exercise interventions can often counteract chemotherapy related toxicity and may help patients to improve or retain physical function and quality of life. Studies evaluating feasibility and the effect of exercise in older patients are lacking. The aim of this study was to investigate the feasibility and effect of an exercise intervention in older frail patients during chemotherapy for colorectal cancer (CRC).

MATERIALS AND METHODS

This is a secondary analysis from the GERICO study investigating the effect of geriatric interventions in frail patients ≥70 years receiving chemotherapy for CRC. All patients in the present analysis were patients randomized to geriatric interventions and who were found physically frail (low handgrip strength or slow 10 m gait speed) and therefore offered referral to the exercise program for twelve weeks. We evaluated reasons for dropping out and feasibility of an individually tailored exercise program twice a week for twelve weeks. Each 60 min session comprised warm-up followed by progressive resistance training and cool-down followed by an oral protein supplement. Baseline characteristics and the effect of exercise for patients with high and low adherence (attendance of <50% of exercise sessions) were compared.

RESULTS

Of 71 patients in the intervention group, 47 (66%) were found physically frail and were offered referral to the exercise program. Seven patients were referred to municipal physiotherapy before study start. In the remaining population (N = 40) 19 had exercise adherence >50% and 21 had no or low exercise adherence. Baseline characteristics were similar between patients with high and low/no adherence, except for sex (68% and 33% were men in high and low/ no adherence group, respectively). Patients with >50% attendance had significant improvements in physical tests after twelve weeks of exercise.

DISCUSSION

Low adherence to the exercise program was seen due to lack of energy and/or treatment related adverse events. Patients with high adherence benefitted from exercise during chemotherapy but did not differ from patients with low adherence at baseline. Consequently, exercise should be offered to all older frail patients receiving chemotherapy for CRC.

Nutrition, Immunosenescence, and Infectious Disease: An Overview of the Scientific Evidence on Micronutrients and on Modulation of the Gut Microbiota

The immune system is key to host defense against pathogenic organisms. Aging is associated with changes in the immune system, with a decline in protective components (immunosenescence), increasing susceptibility to infectious disease, and a chronic elevation in low-grade inflammation (inflammaging), increasing the risk of multiple noncommunicable diseases. Nutrition is a determinant of immune cell function and of the gut microbiota. In turn, the gut microbiota shapes and controls the immune and inflammatory responses. Many older people show changes in the gut microbiota. Age-related changes in immune competence, low-grade inflammation, and gut dysbiosis may be interlinked and may relate, at least in part, to age-related changes in nutrition. A number of micronutrients (vitamins C, D, and E and zinc and selenium) play roles in supporting the function of many immune cell types. Some trials report that providing these micronutrients as individual supplements can reverse immune deficits in older people and/or in those with insufficient intakes. There is inconsistent evidence that this will reduce the risk or severity of infections including respiratory infections. Probiotic, prebiotic, or synbiotic strategies that modulate the gut microbiota, especially by promoting the colonization of lactobacilli and bifidobacteria, have been demonstrated to modulate some immune and inflammatory biomarkers in older people and, in some cases, to reduce the risk and severity of gastrointestinal and respiratory infections, although, again, the evidence is inconsistent. Further research with well-designed and well-powered trials in at-risk older populations is required to be more certain about the role of micronutrients and of strategies that modify the gut microbiota-host relationship in protecting against infection, especially respiratory infection.

The Influence of Heterochronic Non-Myeloablative Bone Marrow Transplantation on the Immune System, Frailty, General Health, and Longevity of Aged Murine Recipients

The stem cell theory of aging postulates that stem cells become inefficient at maintaining the original functions of the tissues. We, therefore, hypothesized that transplanting young bone marrow (BM) to old recipients would lead to rejuvenating effects on immunity, followed by improved general health, decreased frailty, and possibly life span extension. We developed a murine model of non-myeloablative heterochronic BM transplantation in which old female BALB/c mice at 14, 16, and 18(19) months of age received altogether 125.1 ± 15.6 million nucleated BM cells from young male donors aged 7–13 weeks. At 21 months, donor chimerism was determined, and the immune system’s innate and adaptive arms were analyzed. Mice were then observed for general health and frailty until spontaneous death, when their lifespan, post-mortem examinations, and histopathological changes were recorded. The results showed that the old mice developed on average 18.7 ± 9.6% donor chimerism in the BM and showed certain improvements in their innate and adaptive arms of the immune system, such as favorable counts of neutrophils in the spleen and BM, central memory Th cells, effector/effector memory Th and Tc cells in the spleen, and B1a and B1b cells in the peritoneal cavity. Borderline enhanced lymphocyte proliferation capacity was also seen. The frailty parameters, pathomorphological results, and life spans did not differ significantly in the transplanted vs. control group of mice. In conclusion, although several favorable effects are obtained in our heterochronic non-myeloablative transplantation model, additional optimization is needed for better rejuvenation effects.

Effects of a 12-Week Multimodal Exercise Intervention Among Older Patients with Advanced Cancer: Results from a Randomized Controlled Trial

BACKGROUND

Older patients with cancer are at risk of physical decline and impaired quality of life during oncological treatment. Exercise training has the potential to reduce these challenges. The study aim was to investigate the feasibility and effect of a multimodal exercise intervention in older patients with advanced cancer (stages III/IV).

PATIENTS AND METHODS

Eighty-four older adults (≥65 years) with advanced pancreatic, biliary tract, or non-small cell lung cancer who received systemic oncological treatment were randomized 1:1 to an intervention group or a control group. The intervention was a 12-week multimodal exercise-based program including supervised exercise twice weekly followed by a protein supplement, a home-based walking program, and nurse-led support and counseling. The primary endpoint was change in physical function (30-second chair stand test) at 13 weeks.

RESULTS

Median age of the participants was 72 years (interquartile range [IQR] 68-75). Median adherence to the exercise sessions was 69% (IQR 21-88) and 75% (IQR 33-100) for the walking program. At 13 weeks, there was a significant difference in change scores of 2.4 repetitions in the chair stand test, favoring the intervention group (p < .0001). Furthermore, significant beneficial effects were seen for physical endurance (6-minute walk test), hand grip strength, physical activity, symptom burden, symptoms of depression and anxiety, global health status (quality of life), and lean body mass. No effects were seen for dose intensity, hospitalizations, or survival.

CONCLUSION

A 12-week multimodal exercise intervention with targeted support proved effective in improving physical function in older patients with advanced cancer during oncological treatment.

Aging-Related Cellular, Structural and Functional Changes in the Lymph Nodes: A Significant Component of Immunosenescence? An Overview

Aging affects all tissues and organs. Aging of the immune system results in the severe disruption of its functions, leading to an increased susceptibility to infections, an increase in autoimmune disorders and cancer incidence, and a decreased response to vaccines. Lymph nodes are precisely organized structures of the peripheral lymphoid organs and are the key sites coordinating innate and long-term adaptive immune responses to external antigens and vaccines. They are also involved in immune tolerance. The aging of lymph nodes results in decreased cell transport to and within the nodes, a disturbance in the structure and organization of nodal zones, incorrect location of individual immune cell types and impaired intercellular interactions, as well as changes in the production of adequate amounts of chemokines and cytokines necessary for immune cell proliferation, survival and function, impaired naïve T- and B-cell homeostasis, and a diminished long-term humoral response. Understanding the causes of these stromal and lymphoid microenvironment changes in the lymph nodes that cause the aging-related dysfunction of the immune system can help to improve long-term immune responses and the effectiveness of vaccines in the elderly.

Aging impairs human bone marrow function and cardiac repair following myocardial infarction in a humanized chimeric mouse

Ventricular remodeling following myocardial infarction (MI) is a major cause of heart failure, a condition prevalent in older individuals. Following MI, immune cells are mobilized to the myocardium from peripheral lymphoid organs and play an active role in orchestrating repair. While the effect of aging on mouse bone marrow (BM) has been studied, less is known about how aging affects human BM cells and their ability to regulate repair processes. In this study, we investigate the effect aging has on human BM cell responses post‐MI using a humanized chimeric mouse model. BM samples were collected from middle aged (mean age 56.4 ± 0.97) and old (mean age 72.7 ± 0.59) patients undergoing cardiac surgery, CD34^+/− cells were isolated, and NOD‐scid‐IL2rγ^null (NSG) mice were reconstituted. Three months following reconstitution, the animals were examined at baseline or subjected to coronary artery ligation (MI). Younger patient cells exhibited greater repopulation capacity in the BM, blood, and spleen as well as greater lymphoid cell production. Following MI, CD34⁺ cell age impacted donor and host cellular responses. Mice reconstituted with younger CD34⁺ cells exhibited greater human CD45⁺ recruitment to the heart compared to mice reconstituted with old cells. Increased cellular responses were primarily driven by T‐cell recruitment, and these changes corresponded with greater human IFNy levels and reduced mouse IL‐1β in the heart. Age‐dependent changes in BM function led to significantly lower survival, increased infarct expansion, impaired host cell responses, and reduced function by 4w post‐MI. In contrast, younger CD34⁺ cells helped to limit remodeling and preserve function post‐MI.

Mitochondria and the Tumour Microenvironment in Blood Cancer

The bone marrow (BM) is a complex organ located within the cavities of bones. The main function of the BM is to produce all the blood cells required for a normal healthy blood system. As with any major organ, many diseases can arise from errors in bone marrow function, including non-malignant disorders such as anaemia and malignant disorders such as leukaemias. This article will explore the role of the bone marrow, in normal and diseased haematopoiesis, with an emphasis on the requirement for intercellular mitochondrial transfer in leukaemia.

Integrated Safety Analysis of Abrocitinib for the Treatment of Moderate-to-Severe Atopic Dermatitis From the Phase II and Phase III Clinical Trial Program

Background

Pivotal phase III studies demonstrated that abrocitinib, an oral, once-daily, JAK1-selective inhibitor, is effective treatment for moderate-to-severe atopic dermatitis (AD) as monotherapy and in combination with topical therapy.

Objective

The aim of this study was to evaluate the long-term safety of abrocitinib 200 mg and 100 mg in an integrated analysis of a phase IIb study, four phase III studies, and one long-term extension study.

Methods

Two cohorts were analyzed: a placebo-controlled cohort from 12- to 16-week studies and an all-abrocitinib cohort including patients who received one or more abrocitinib doses. Adverse events (AEs) of interest and laboratory data are reported.

Results

Total exposure in the all-abrocitinib cohort (n = 2856) was 1614 patient-years (PY); exposure was ≥ 24 weeks in 1248 patients and ≥ 48 weeks in 606 (maximum 108 weeks). In the placebo-controlled cohort (n = 1540), dose-related AEs (200 mg, 100 mg, placebo) were nausea (14.6%, 6.1%, 2.0%), headache (7.8%, 5.9%, 3.5%), and acne (4.7%, 1.6%, 0%). Platelet count was reduced transiently in a dose-dependent manner; 2/2718 patients (200-mg group) had confirmed platelet counts of < 50 × 10³/mm³ at week 4. Incidence rates (IRs) were 2.33/100PY and 2.65/100 PY for serious infection, 4.34/100PY and 2.04/100PY for herpes zoster, and 11.83/100PY and 8.73/100PY for herpes simplex in the 200-mg and 100-mg groups, respectively. IRs for nonmelanoma skin cancer, other malignancies, and major adverse cardiovascular events were < 0.5/100PY for both doses. Five venous thromboembolism events occurred (IR 0.30/100PY), all in the 200-mg group. There were three deaths due to gastric carcinoma (diagnosed at day 43), sudden death, and COVID-19.

Conclusion

Abrocitinib, with proper patient and dose selection, has a manageable tolerability and longer-term safety profile appropriate for long-term use in patients with moderate-to-severe AD.

Trial Registries

ClinicalTrials.gov: NCT02780167, NCT03349060, NCT03575871, NCT03720470, NCT03627767, NCT03422822.

Video abstract

Clinical outcomes of frozen autograft reconstruction for the treatment of primary bone sarcoma in adolescents and young adults

Age affects the clinical outcomes of cancer treatment, including those for bone sarcoma. Successful reconstruction using frozen autograft after excision of bone sarcoma has been reported; however, little is known about the clinical outcomes of frozen autograft reconstruction according to age. The purpose was to evaluate the clinical outcomes of the frozen autograft reconstruction focusing on skeletally mature adolescents and young adults (AYAs) that was 15 to 39 years of age. A total of 37 AYA patients with primary bone sarcoma on the appendicular skeleton were enrolled in this study. The mean follow-up period was 89 months. The graft survival (GS), overall survival (OS), recurrence-free survival (RFS), complications and the function were retrospectively evaluated using medical records. The 10-year GS, OS, and RFS rates were 76%, 84%, and 79%, respectively. Bone union was achieved with a rate of 94% within 1 year after surgery, and nonunion (n = 1) and fracture (n = 2) were infrequently observed. Graft removal was performed in 7 cases, and the most common reason for the removal was infection (n = 5). The Musculoskeletal Tumor Society score was excellent in 23 cases of the available 29 cases. Frozen autograft reconstruction for AYAs showed excellent clinical outcomes, although the long-term follow-up is required.

Cellular senescence in lymphoid organs and immunosenescence

Immunosenescence is a multi-faceted phenomenon at the root of age-associated immune dysfunction. It can lead to an array of pathological conditions, including but not limited to a decreased capability to surveil and clear senescent cells (SnCs) and cancerous cells, an increased autoimmune responses leading to tissue damage, a reduced ability to tackle pathogens, and a decreased competence to illicit a robust response to vaccination. Cellular senescence is a phenomenon by which oncogene-activated, stressed or damaged cells undergo a stable cell cycle arrest. Failure to efficiently clear SnCs results in their accumulation in an organism as it ages. SnCs actively secrete a myriad of molecules, collectively called senescence-associated secretory phenotype (SASP), which are factors that cause dysfunction in the neighboring tissue. Though both cellular senescence and immunosenescence have been studied extensively and implicated in various pathologies, their relationship has not been greatly explored. In the wake of an ongoing pandemic (COVID-19) that disproportionately affects the elderly, immunosenescence as a function of age has become a topic of great importance. The goal of this review is to explore the role of cellular senescence in age-associated lymphoid organ dysfunction and immunosenescence, and provide a framework to explore therapies to rejuvenate the aged immune system.

Improved function and balance in T cell modulation by endothelial cells in young people

Elderly individuals exhibit unbalanced bone marrow (BM) effector T cell subset differentiation, such as increased T helper type 1 (Th1) and T cytotoxic type 1 (Tc1) cell frequencies, but the underlying mechanism is still unclear. Endothelial cells (ECs), which are instructive components of the BM microenvironment, exhibit the phenotype of semi-professional antigen-presenting cells and regulate T cell recruitment and activation. Thus, we compared the frequency and function of BM ECs, especially their capacity to regulate effector T cell subsets, between young and elderly healthy individuals, and explored the underlying mechanism of this immunomodulatory discrepancy. Although the young and elderly EC percentages were comparable, young ECs showed fewer reactive oxygen species and better migratory and tube-forming abilities than elderly ECs. Notably, increased T cell activation molecules and inflammatory cytokines were found in elderly ECs which regulated T cells to differentiate into more proinflammatory T cells, including Th1 and Tc1 cells, than young ECs.

Frailty and aging-associated syndromes in lung transplant candidates and recipients

Many lung transplant candidates and recipients are older and frailer compared to previous eras. Older patients are at increased risk for pre- and posttransplant mortality, but this risk is not explained by numerical age alone. This manuscript represents the product of the American Society of Transplantation (AST) conference on frailty. Experts in the field reviewed the latest published research on assessment of elderly and frail lung transplant candidates. Physical frailty, often defined as slowness, weakness, low physical activity, shrinking, and exhaustion, and frailty evaluation is an important tool for evaluation of age-associated dysfunction. Another approach is assessment by cumulative deficits, and both types of frailty are common in lung transplant candidates. Frailty is associated with death or delisting before transplant, and may be associated with posttransplant mortality. Sarcopenia, cognitive dysfunction, depression, and nutrition are other important components for patient evaluation. Aging-associated inflammation, telomere dysfunction, and adaptive immune system senescence may also contribute to frailty. Developing tools for frailty assessment and interventions holds promise for improving patient outcomes before and after lung transplantation.

Activation of Bone Marrow Adaptive Immunity in Type 2 Diabetes: Rescue by Co-stimulation Modulator Abatacept

Background: Chronic low-grade inflammation and alterations in innate and adaptive immunity were reported in Type 2 diabetes (T2D). Here, we investigated the abundance and activation of T cells in the bone marrow (BM) of patients with T2D. We then verified the human data in a murine model and tested if the activation of T cells can be rescued by treating mice with abatacept, an immunomodulatory drug employed for the treatment of rheumatoid arthritis. Clinical evidence indicated abatacept can slow the decline in beta-cell function.

Methods: A cohort of 24 patients (12 with T2D) undergoing hip replacement surgery was enrolled in the study. Flow cytometry and cytokine analyses were performed on BM leftovers from surgery. We next compared the immune profile of db/db and control wt/db mice. In an additional study, db/db mice were randomized to receive abatacept or vehicle for 4 weeks, with endpoints being immune cell profile, indices of insulin sensitivity, and heart performance.

Results: Patients with T2D showed increased frequencies of BM CD4⁺ (2.8-fold, p = 0.001) and CD8⁺ T cells (1.8-fold, p = 0.01), with the upregulation of the activation marker CD69 and the homing receptor CCR7 in CD4⁺ (1.64-fold, p = 0.003 and 2.27-fold, p = 0.01, respectively) and CD8⁺ fractions (1.79-fold, p = 0.05 and 1.69-fold, p = 0.02, respectively). These differences were confirmed in a multivariable regression model. CCL19 (CCR7 receptor ligand) and CXCL10/11 (CXCR3 receptor ligands), implicated in T-cell migration and activation, were the most differentially modulated chemokines. Studies in mice confirmed the activation of adaptive immunity in T2D. Abatacept reduced the activation of T cells and the levels of proinflammatory cytokines and improved cardiac function but not insulin sensitivity.

Conclusions: Results provide proof-of-concept evidence for the activation of BM adaptive immunity in T2D. In mice, treatment with abatacept dampens the activation of adaptive immunity and protects from cardiac damage.

The aging transplant population and immunobiology: any therapeutic implication?

PURPOSE OF REVIEW

The aim of this review is to describe the latest investigations into the immunobiology of aging and the potential impact on outcomes after mechanical circulatory support implantation and heart transplantation. This information is relevant given the growing numbers of older patients with heart failure undergoing evaluation for mechanical circulatory support device (MCSD) or heart transplantation.

RECENT FINDINGS

A host of aging-associated aspects of immune dysfunction have been described in the general population including T-cell senescence, exhaustion, and terminal dedifferentiation, as well as impaired function of innate immune cells. Another important consequence of T-cell senescence is inflammation, which is known to have a strong relationship with both heart failure and frailty in older patients. Recent data on the association between T-cell and monocyte phenotypes as well as evaluation of gene expression and adverse outcomes after MCSD suggests the potential value of immunologic assessment of MCSD and heart transplant candidates and recipients. Measurement of physical frailty represents another avenue for patient evaluation that may complement immunologic assessment. Determination of immune dysfunction and frailty prior to transplantation may have implications for choice of induction and dosing of maintenance immunosuppression.

SUMMARY

As the age of transplant and MCSD candidates and recipients continues to increase, it is important for providers to recognize the potential impact of aging-associated immune dysfunction and how it may influence candidate selection, postintervention monitoring, and adjustment of immunosuppression.

DNA Methylation Age Is More Closely Associated With Infection Risk Than Chronological Age in Kidney Transplant Recipients

Older kidney transplant recipients demonstrate increased rates of infection but decreased rates of rejection compared with younger recipients, suggesting that older transplant patients are functionally overimmunosuppressed. We hypothesized that this is a consequence of reduction in immunological activity due to biological aging and that an immune biological age, as determined by DNA methylation (DNAm), would be associated more strongly with incidence of infection than chronological age.

Methods

DNAm analysis was performed on peripheral blood mononuclear cell collected from 60 kidney transplant recipients representing older (≥age 60 y) and younger (aged 30-59 y) patients 3 months after transplantation. DNAm age was calculated based on methylation status of a panel of CpG sites, which have been previously identified as indicative of biological age.

Results

Correlation was seen between chronological and DNAm age; however, there were many patients with significant differences (either acceleration or slowing) between DNAm age and chronological age. A statistically significant association was seen between increased DNAm age and incidence of infection in the first year after kidney transplantation, whereas no significant association was seen between chronological age and infection.

Conclusions

Assessment of DNAm age holds promise as an approach for patient evaluation and individualization of immune suppression regimens. This analysis may provide insights into the immunological mechanism behind increased incidence of infection observed in older transplant patients. The ability to measure biological age would allow for patient risk stratification and individualization of immunosuppression, improving outcomes for the growing numbers of older patients undergoing kidney transplantation.

The memory of the fatty acid system

Mental memory system has sensory memory, short-term memory, working memory, and long-term memory. Working memory "keeps things in mind in parallel" when performing complex tasks. Similar aspects can be found for immunological memory. However, there exists another one, the memory of the fatty acid system. This article shows sensory memory of the fatty acid system, which is the perception apparatus of small intestine enterocytes (CD36, SR-B1, FATP4, FABP1, FABP2) and hepatocytes. In these cells, the fatty acid short-term memory is located, consisting of a cytoplasmic lipid droplet cycle. Similar like a working memory in the brain, the short-term memory of enterocytes and hepatocytes use parallel processing and recourse to long-term fatty acid memory. The fatty acid long-term memory is far away from these primary points of uptake. It is located in the adipocyte and in cellular membranes. The process of building a fatty acid memory is described with constructs like sensing environmental material, encoding, consolidation, long-term storage, retrieval, re-encoding, re-consolidation, and renewed long-term storage. The article illustrates the dynamics of building a fatty acid memory, the information content of fatty acids including the code, the roles of fatty acids in the body, and a new understanding of the expression "you are what you eat". The memory of the fatty acid system, plays a decisive role in integrating environmental signals over time (diet and microbiome).

Effects of A Personalized Intervention Program on the Biochemical and Hematological Profile in Community Dwelling Old Adults-The AGA@4life Intervention Model

Aging is a social and economic challenge of the highest importance and a multidisciplinary intervention seems to be a promising approach for improving the quality of life of elderly individuals. This project was designed aimed at promoting an active and healthy aging through the implementation of an intervention program based on the comprehensive geriatric assessment model (AGA@4life), focused on promoting health and wellbeing, independence and autonomy, mobility, and social inclusion. A non-randomized interventional study was designed to evaluate the effect of only a dietetic and nutritional approach (control group (CG)) and the combination of a tailored exercise program and a dietetic and nutritional approach (intervention group (IG)) in the biochemical and hematological profile of older adults in the framework of AGA@4life. The 34 participants enrolled, aged 65 years or over, were subject to a thorough baseline (T0) multidisciplinary diagnostic evaluation, including the gathering of clinical information and a battery of biochemical and hematological determinations, and reevaluated after eight weeks of intervention (T1). Between T0 and T1, an increase in albumin and total proteins serum levels were observed in both groups (p < 0.01); the hematological profile in CG and IG showed an increase in red cell count and hemoglobin (p < 0.05). In IG, an increase of HDL cholesterol (p < 0.001) and a decrease of triglycerides (p = 0.001) were still observed. The AGA@4life multidisciplinary intervention improved the hematological and biochemical profile of old adults, potentially contributing to delay the development of several aging comorbidities and increase the quality of life of participants.

Effectiveness of 23-valent pneumococcal polysaccharide vaccine on elderly patients with colorectal cancer: A population-based propensity score-matched cohort study

The commonly used vaccine for adults with a high risk of pneumonia is 23-valent pneumococcal polysaccharide vaccine (PPSV23). However, its effectiveness in patients with colorectal cancer has not been investigated. This study aimed to investigate the effectiveness of PPSV23 in reducing the risk of pneumonia among elderly patients with colorectal cancer.A total of 120,605 newly diagnosed patients with colorectal cancer were identified from the Taiwan National Health Insurance Research Database between 1996 and 2010. Of these patients, 18,468 were 75 years or older in 2007 to 2010, and 3515 received PPSV23. People aged 75 years or older have been considered eligible for receiving PPSV23 vaccination in Taiwan since 2007. The specific "vaccination period" of October 2008 to December 2008 was used to minimize the potential immortal time bias. Therefore, 893 patients who received PPSV23 outside this vaccination period or died before 2009 and 2960 unvaccinated patients who died before 2009 were excluded. After the propensity score was matched with a 1:3 ratio, 2622 vaccinated patients and 7866 unvaccinated patients were recruited. A multivariate log-linear Poisson regression model was performed and adjusted for potential confounders, including influenza vaccination, vaccination period, cancer treatment modalities, comorbidities, and sociodemographic variables.After 2 years of follow-up, the incidence rate of the pneumonia hospitalization of the vaccinated patients was significantly lower than that of the unvaccinated patients at 85.53 per 1000 person-years (PYs) of the former and 92.38 per 1000 PYs of the latter. The proportions of patients who had 2, 3, and >3 pneumonia hospitalizations per year were consistently lower in the vaccinated group than in the unvaccinated group (1.9% vs 2.0%, 0.5% vs 0.9%, and 0.7% vs 1.1%, respectively). After adjustment for covariates was made, PPSV23 vaccine was significantly associated with a reduced risk of pneumonia hospitalization, with an adjusted incidence rate ratio of 0.88 (P = .040). The overall pneumonia-free survival rate was also significantly higher in the vaccinated patients than in the unvaccinated patients (P = .001).PPSV23 vaccination was associated with a significantly reduced rate of pneumonia hospitalization in elderly patients with colorectal cancer.

Research progress on immune aging and its mechanisms affecting geriatric diseases

Immunosenescence, also known as immune aging, refers to the degeneration, compensation, and reconstruction of the immune system with aging. Immune aging is an important factor in the increased susceptibility of the elderly to infectious diseases, malignant tumors, and a variety of chronic diseases and has long been a hotspot in geriatrics and immunology research. In this paper, the characteristics and progression of immune aging are briefly reviewed for clinicians' reference.

Progressive ossification of the bone marrow vasculature with advancing age corresponds with reduced red blood cell count and percentage of circulating lymphocytes in male Fischer-344 rats

OBJECTIVE

Assess the link between bone marrow blood vessel ossification, Tb. and cortical bone, and hematological parameters across the lifespan in rats.

METHODS

Right femora and whole blood samples were taken from male Fischer-344 rats at 1, 6, 12, 18 and 24 months. Femora were scanned by micro-computed tomography (MicroCT) to determine bone marrow blood vessel ossification (ie, ossified vessel volume [OsVV], ossified vessel thickness (OsV.Th), ossified vessel density (OsV density), and structural model index [SMI]). Bone microarchitecture (ie, bone volume [BV/TV], trabecular thickness, trabecular number, and trabecular separation), density and SMI, and cortical bone parameters (ie, cortical shell thickness, porosity, and density) were also determined by MicroCT. Complete blood counts with differentials were conducted.

RESULTS

Ossified vessel volume increased throughout the lifespan, coinciding with reduced trabecular BV/TV and cortical shell thickness at 24 months. Many of the hematological parameters were unchanged (ie, white blood cells, lymphocyte number) or increased (monocyte number, percent monocyte, granulocyte number, percent granulocyte, hemoglobin, hematocrit, mean corpuscular hemoglobin concentration, red blood cell distribution width, platelet, mean platelet volume) with advancing age; however, red blood cells (RBC) and percent lymphocytes (LY%) were reduced at 24 months. In addition, OsV density was similar to trabecular bone density.

CONCLUSIONS

Declines in trabecular BV/TV, cortical shell thickness, RBC, and LY% with advanced age coincided with augmented ossification of bone marrow blood vessels.

The impact of oxidative stress, inflammation, and senescence on the maintenance of immunological memory in the bone marrow in old age

The bone marrow (BM) provides a preferential survival environment for the long-term maintenance of antigen-experienced adaptive immune cells. After the contact with antigens, effector/memory T cells and plasma cell precursors migrate to the BM, in which they can survive within survival niches in an antigen-independent manner. Despite this, the phenotype of adaptive immune cells changes with aging, and BM niches themselves are affected, leading to impaired long-term maintenance of immunological memory in the elderly as a result. Oxidative stress, age-related inflammation (inflammaging), and cellular senescence appear to play a major role in this process. This review will summarize the age-related changes in T and B cell phenotype, and in the BM niches, discussing the possibility that the accumulation of highly differentiated, senescent-like T cells in the BM during aging may cause inflammation in the BM and promote oxidative stress and senescence. In addition, senescent-like T cells may compete for space with other immune cells within the marrow, partially excluding effector/memory T cells and long-lived plasma cells from the niches.

Differences in Gene Expression in Older Compared With Younger Kidney Transplant Recipients

BACKGROUND

For the growing numbers of older transplant patients, increased incidence of infection and death compared with younger patients may limit the many benefits provided by transplantation. However, little is known about age-associated immune dysfunction in the older transplant recipient.

METHODS

A cohort of 60 kidney transplant recipients, 23 older (≥ 60y) and 37 younger (30-59y), matched on antithymocyte induction and donor type (living vs deceased) was evaluated. Gene expression in peripheral blood mononuclear cells 3 months after kidney transplantation was analyzed to compare differences between older and younger patients.

RESULTS

Proinflammatory genes were upregulated in older kidney transplant patients, including cytokines IL1-β and IL-6. Downregulated genes were associated with B-cell and T-cell function, including CCR7 and CD27. Analysis of predicted transcription factor binding suggested an increase in proinflammatory transcription factor CCAAT/enhancer binding protein β-binding sites in older patients, whereas interferon regulatory factor 2 transcription factor binding sites were less prevalent.

CONCLUSIONS

Older kidney transplant recipients exhibited multiple differences in gene expression compared with younger patients, with upregulation of proinflammatory genes and downregulation of adaptive immune response genes. These findings may explain the mechanism of increased vulnerability to infection and malignancy observed in older transplant patients.

Impact of aging on bone, marrow and their interactions

Hematopoiesis in land dwelling vertebrates and marine mammals occurs within the bone marrow, continually providing mature progeny over the course of an organism's lifetime. This conserved dependency highlights the critical relationship between these two organs, yet the skeletal and hematopoietic systems are often thought of as separate. In fact, data are beginning to show that skeletal disease pathogenesis influences hematopoiesis and viceversa, offering novel opportunities to approach disease affecting bone and blood. With a growing global population of aged individuals, interest has focused on cell autonomous changes in hematopoietic and skeletal systems that result in dysfunction. The purpose of this review is to summarize the literature on aging effects in both fields, and provide critical examples of organ cross-talk in the aging process.

Transfused trauma patients have better outcomes when transfused with blood components from young donors

The physiology of tissue healing and aging share common pathways. Both patient age and tissue healing are crucial factors predicting outcomes in trauma patients. The presented hypothesis focuses on the concept that transfused trauma patients have better outcomes when transfused with blood components from young donors. The age of the donor of a blood transfusion could affect recovery following a major traumatic insult and help avoid postinjury immune paralysis and its associated complications. The frequent transfusion of blood components to the severely injured trauma patient provides an opportunity for the recipient to benefit from the potentially favourable effect of blood originating from young donors. Different types of evidence support the presented hypothesis including work on soluble circulating factors, research on animal parabiontic models and epidemiological studies. Theories on the role of transfusion of cells, on bone marrow and on senolytics also represent grounds to elaborate pathways to test this hypothesis. The precise molecular mechanism underlying this hypothesis is uncertain. A beneficial effect on trauma patients following transfusion of blood could be due to a positive effect of blood donated from younger donors or instead to the lack of a negative effect possibly occurring when transfusing blood from older donors. Either way, identifying this mechanism would provide a powerful tool enhance long and short term recovery after trauma.

Increased T cell immunosenescence and accelerated maturation phenotypes in older kidney transplant recipients

Older kidney transplant recipients experience increased rates of infection and death, and less rejection, compared with younger patients. However, little is known about immune dysfunction in older compared with younger kidney transplant recipients and whether it is associated with infection. We evaluated T cell phenotypes including maturation, immune senescence, and exhaustion in a novel investigation into differences in older compared with younger patients receiving identical immune suppression regimens. We evaluated PBMC from 60 kidney transplant recipients (23 older and 37 matched younger patients) by multiparameter immune phenotyping. Older kidney transplant recipients demonstrated decreased frequency of naïve CD4+ and CD8+ T cells, and increased frequency of terminally differentiated, immune senescent, and NK T cells expressing KLRG1. There was a trend towards increased frequency of T cell immune senescence in patients experiencing infection in the first year after transplantation, which reached statistical significance in a multivariate analysis. This pilot study reveals immune dysfunction in older compared with younger transplant recipients, and suggests a likely mechanism for increased vulnerability to infection. The ability to assess T cell maturation and immune senescence in transplant recipients offers the potential for risk stratification and customization of immune suppression to prevent infection and rejection after transplantation.

Neutrophil to Lymphocyte Ratio as a Prognostic Predictor in Older People With Acute Coronary Syndrome

The neutrophil to lymphocyte ratio (NLR) at admission is a prognostic marker for acute coronary syndrome (ACS). However, no study was performed exclusively with older people. The present study evaluated the NLR in older people with ACS as a predictor of death, combined major in-hospital outcomes (death, stroke, reinfarction), hospital stay, ventricular ejection fraction, use of vasoactive drugs, and extent of coronary artery disease. We conducted a retrospective cohort study with in-hospital follow-up using data from a single center in Recife, Brazil. Patients aged 60 and older admitted with ACS were selected. The patients were followed until discharge or death. A total of 272 individuals were evaluated; 55.8% were men and the mean age was 73 years. The NLR was not a predictor of in-hospital death. A higher NLR upon admission was associated with a longer hospital stay (β = 0.131; 95% confidence interval [CI]: 0.017-0.246; P = .024) and an ejection fraction <50% (relative risk = 2.1; 95% CI: 1.19-3.57; P = .001). The other outcomes did not reach significance. The NLR was associated with a longer hospital stay and a left ventricular ejection fraction <50% in older people with ACS.

From the Cover: Tributyltin Alters the Bone Marrow Microenvironment and Suppresses B Cell Development

Organotins are industrial chemicals and agricultural pesticides, and they contaminate both outdoor and indoor environments. Organotins are detectable in human sera at biologically active concentrations and are immuno-and neuro-toxicants. Triphenyltin, tributyltin (TBT) and dibutyltin activate peroxisome proliferator-activated receptor γ in bone marrow multipotent mesenchymal stromal cells and promote adipogenesis. TBT also has been shown to suppress osteogenesis; osteoblasts not only support bone homeostasis but also support B lymphopoiesis. In addition, developing B cells are highly sensitive to exogenous insults. Thus, we hypothesized that bone marrow B cells may be negatively affected by TBT exposure both directly, through activation of apoptosis, and indirectly, through alterations of the bone marrow microenvironment. TBT activated apoptosis in developing B cells at environmentally relevant concentrations (as low as 80 nM) in vitro, via a mechanism that is distinct from that induced by high dose (μM) TBT and that requires p53. TBT suppressed the proliferation of hematopoietic cells in an ex vivo bone marrow model. Concurrent treatment of stromal cells and B cells or pretreatment of stromal cells with TBT induced adipogenesis in the stromal cells and reduced the progression of B cells from the early pro B (Hardy fraction B) to the pre B stage (Hardy fraction D). In vivo, TBT induced adipogenesis in bone marrow, reduced "aging-sensitive" AA4+CD19+ B cells in bone marrow, and reduced splenic B cell numbers. Immunosenescence and osteoporosis are adverse health effects of aging, we postulate that TBT exposure may mimic, and possibly intensify, these pathologies.

Burn wounds in the young versus the aged patient display differential immunological responses

BACKGROUND

Individuals in the geriatric age range are more prone than younger individuals to convert their partial thickness thermal burns into full thickness injuries. We hypothesized that this often observed clinical phenomenon is strongly related to differential local injury responses mediated by the immune system.

MATERIALS & METHODS

Skin samples from areas with partial thickness thermal burns were obtained during routine excision and grafting procedures between post burn days 2-6. Tissue samples were grouped by age ranges with young patients defined as <30 years of age or aged patients defined as >65. Formalin fixed samples were used to confirm depth of burn injury and companion sections were homogenized for multiplex analysis using a Luminex platform. Immunohistochemical staining was used to quantify total macrophage numbers as well as the M1 and M2 subpopulations.

RESULTS

Our analysis includes samples derived from 11 young subjects (mean age=23) and 3 aged subjects (mean age=79.2). Our initial survey of analytes examined 31 cytokines/chemokines. Twelve were excluded from consideration as they were present in concentrations either above or below the optimal detection range. Two analytes emerged as candidate molecules with significant differences between the young and the aged patient responses to burn injury. EGF levels were on average 21.69pg/ml in young vs 14.87pg/ml in aged (p=0.032). RANTES/CCL5 levels were on average 14.86pg/ml in young vs 4.26pg/ml in aged (p=0.026). Elevated macrophage numbers were present within wounds of younger patients compared to the old (p<0.01), with a higher concentration of the M1 type in the elderly (p>0.05).

CONCLUSION

Our study has identified at least 2 well known cytokines, CCL5 (RANTES) and EGF, which are differentially regulated in response to burn injury by young versus aged burn victims. Evidence suggests that a proinflammatory environment can explain the high conversion rate from partial to full thickness burns. Our data suggest the need for future studies at the point of injury (cutaneous targets) that may be modulated by post burn release of cytokines/chemokines.

Effectiveness of 23-valent pneumococcal polysaccharide vaccine on elderly long-term cancer survivors: a population-based propensity score matched cohort study

OBJECTIVE

The Advisory Committee on Immunization Practices in 2012 recommended the 23-valent pneumococcal polysaccharide vaccine (PPSV23) for adults with high risk of pneumonia. However, its effectiveness in cancer survivors has not been investigated. Our aim was to investigate the effectiveness of PPSV23 in these patients.

DESIGN

Population-based matched cohort study.

SETTING

Claim data were obtained from 1 million people registered with the National Health Insurance Research Database in 1996, and followed to 2010. People aged ≥75 years are eligible for receiving PPSV23 vaccination in Taiwan since 2007.

PARTICIPANTS

Among the 30 249 patients with cancer, 6784 patients were 75 years or older eligible for PPSV23 vaccination. Among them, 1887 survived 5 or more years (ie, cancer survivors) after cancer diagnosis. We identified 377 cancer survivors who received PPSV23. A total of 754 propensity score matched unvaccinated patients were randomly selected.

INTERVENTION

PPSV23 vaccination.

PRIMARY OUTCOME MEASURES

The primary outcome was pneumonia hospitalisation. Potential confounders include influenza vaccination, vaccination period, cancer treatment modalities, comorbidities and sociodemographic variables.

RESULTS

After 2 years of follow-up, vaccinated patients had a significantly lower incidence rate of pneumonia hospitalisation at 73.66 per 1000 person-years (PYs), compared with 117.82 per 1000 PYs for unvaccinated patients. Additionally, the prevalence for pneumonia hospitalisation frequency of >0-1,>1-2,>2-3 and >3 times per PY was all consistently lower in the vaccinated group (6.63% vs 9.28%, 1.86% vs 2.52%, 0.80% vs 1.59% and 0.27% vs 0.53%, respectively). After adjustment for covariates, PPSV23 vaccine was significantly associated with reduced pneumonia hospitalisation risk, with an adjusted incidence rate ratio of 0.695 (p=0.030). While the cumulative pneumonia incidence was also significantly lower in the vaccinated patients (p=0.027), the overall survival time was similar (p=0.136).

CONCLUSIONS

PPSV23 vaccination was associated with a significantly reduced rate of pneumonia hospitalisation in long-term cancer survivors.

Resveratrol counteracts bone loss via mitofilin-mediated osteogenic improvement of mesenchymal stem cells in senescence-accelerated mice

Rational: Senescence of mesenchymal stem cells (MSCs) and the related functional decline of osteogenesis have emerged as the critical pathogenesis of osteoporosis in aging. Resveratrol (RESV), a small molecular compound that safely mimics the effects of dietary restriction, has been well documented to extend lifespan in lower organisms and improve health in aging rodents. However, whether RESV promotes function of senescent stem cells in alleviating age-related phenotypes remains largely unknown. Here, we intend to investigate whether RESV counteracts senescence-associated bone loss via osteogenic improvement of MSCs and the underlying mechanism.

Methods: MSCs derived from bone marrow (BMMSCs) and the bone-specific, senescence-accelerated, osteoblastogenesis/osteogenesis-defective mice (the SAMP6 strain) were used as experimental models. In vivo application of RESV was performed at 100 mg/kg intraperitoneally once every other day for 2 months, and in vitro application of RESV was performed at 10 μM. Bone mass, bone formation rates and osteogenic differentiation of BMMSCs were primarily evaluated. Metabolic statuses of BMMSCs and the mitochondrial activity, transcription and morphology were also examined. Mitofilin expression was assessed at both mRNA and protein levels, and short hairpin RNA (shRNA)-based gene knockdown was applied for mechanistic experiments.

Results: Chronic intermittent application of RESV enhances bone formation and counteracts accelerated bone loss, with RESV improving osteogenic differentiation of senescent BMMSCs. Furthermore, in rescuing osteogenic decline under BMMSC senescence, RESV restores cellular metabolism through mitochondrial functional recovery via facilitating mitochondrial autonomous gene transcription. Molecularly, in alleviating senescence-associated mitochondrial disorders of BMMSCs, particularly the mitochondrial morphological alterations, RESV upregulates Mitofilin, also known as inner membrane protein of mitochondria (Immt) or Mic60, which is the core component of the mitochondrial contact site and cristae organizing system (MICOS). Moreover, Mitofilin is revealed to be indispensable for mitochondrial homeostasis and osteogenesis of BMMSCs, and that insufficiency of Mitofilin leads to BMMSC senescence and bone loss. More importantly, Mitofilin mediates resveratrol-induced mitochondrial and osteogenic improvements of BMMSCs in senescence.

Conclusion: Our findings uncover osteogenic functional improvements of senescent MSCs as critical impacts in anti-osteoporotic practice of RESV, and unravel Mitofilin as a novel mechanism mediating RESV promotion on mitochondrial function in stem cell senescence.

Lower antibody functionality in middle-aged adults compared to adolescents after primary meningococcal vaccination: Role of IgM

INTRODUCTION

Successful vaccination of elderly persons is often hampered by immunological ageing, leaving part of the elderly population vulnerable for infectious diseases. As an alternative, timely vaccinations might be administered at middle-age, before reaching old age. Studies evaluating the immunological fitness of middle-aged adults are warranted. In this study we compared the immunogenicity of a primary meningococcal vaccination in Dutch middle-aged adults with that in adolescents, in order to gain knowledge on the early signs of immune ageing.

METHODS

In this study, we compared the antibody responses after a primary meningococcal vaccination between middle-aged adults (50-65years of age, N=204) and adolescents (10-15years of age, N=225). Blood samples were taken pre-, as well as 28days and 1year post-vaccination. Functional antibody titers were measured with the serum bactericidal killing assay using baby rabbit complement (rSBA). Meningococcal polysaccharide (PS) specific IgG and IgM concentrations were determined with a fluorescent bead-based multiplex immunoassay.

RESULTS

Lower post-vaccination functional antibody titers against meningococcal group W and Y were observed in the middle-aged adults compared to the adolescents. One year post-vaccination, also a significantly higher proportion of the middle-aged adults possessed an rSBA titer below protection level. A large reduction in post-vaccination IgM concentrations was observed in the middle-aged adults, whereas IgG concentrations were only marginally different between the two age groups. Strong correlations between the post-vaccination rSBA titers and IgM concentrations were found both in the middle-aged adults and the adolescents.

CONCLUSION

Although protective antibody titers were initiated after primary meningococcal vaccination in middle-aged adults, antibody functionality was significantly lower as compared to that in adolescents. This difference was mainly caused by lower IgM responses. Our results indicate early signs of immune ageing in middle-aged adults, which is important knowledge for the development of future vaccine strategies to better protect elderly persons against infectious diseases.

The effects of red cell transfusion donor age on nosocomial infection among trauma patients

BACKGROUND

We hypothesized that packed red blood cell (PRBC) transfusions from older donors would be associated with fewer nosocomial infections among trauma patients.

METHODS

We performed a four-year retrospective analysis of 264 consecutive adult trauma patients who received ≥1 PRBC transfusion during admission. The capacity of donor age to predict nosocomial infection was assessed by logistic regression.

RESULTS

Thirty-three percent of all patients developed a nosocomial infection. Donor age was significantly higher among patients with nosocomial infection (40.3 vs. 37.6 years, p = 0.035), and the incidence of infection was directly proportional to donor age. The association between donor age and infection was strongest among recipients age ≥60 years, and was significant on multivariate regression for this cohort (OR 1.07 (95% CI 1.01-1.13), p = 0.024).

CONCLUSIONS

Among trauma patients receiving PRBC transfusions, blood from older donors may be associated with increased risk for nosocomial infection.

Immunosenescence-Related Transcriptomic and Immunologic Changes in Older Individuals Following Influenza Vaccination

The goal of annual influenza vaccination is to reduce mortality and morbidity associated with this disease through the generation of protective immune responses. The objective of the current study was to examine markers of immunosenescence and identify immunosenescence-related differences in gene expression, gene regulation, cytokine secretion, and immunologic changes in an older study population receiving seasonal influenza A/H1N1 vaccination. Surprisingly, prior studies in this cohort revealed weak correlations between immunosenescence markers and humoral immune response to vaccination. In this report, we further examined the relationship of each immunosenescence marker (age, T cell receptor excision circle frequency, telomerase expression, percentage of CD28⁻ CD4⁺ T cells, percentage of CD28⁻ CD8⁺ T cells, and the CD4/CD8 T cell ratio) with additional markers of immune response (serum cytokine and chemokine expression) and measures of gene expression and/or regulation. Many of the immunosenescence markers indeed correlated with distinct sets of individual DNA methylation sites, miRNA expression levels, mRNA expression levels, serum cytokines, and leukocyte subsets. However, when the individual immunosenescence markers were grouped by pathways or functional terms, several shared biological functions were identified: antigen processing and presentation pathways, MAPK, mTOR, TCR, BCR, and calcium signaling pathways, as well as key cellular metabolic, proliferation and survival activities. Furthermore, the percent of CD4⁺ and/or CD8⁺ T cells lacking CD28 expression also correlated with miRNAs regulating clusters of genes known to be involved in viral infection. Integrated (DNA methylation, mRNA, miRNA, and protein levels) network biology analysis of immunosenescence-related pathways and genesets identified both known pathways (e.g., chemokine signaling, CTL, and NK cell activity), as well as a gene expression module not previously annotated with a known function. These results may improve our ability to predict immune responses to influenza and aid in new vaccine development, and highlight the need for additional studies to better define and characterize immunosenescence.

Safety of Antithrombotic Agents in Elderly Patients with Acute Coronary Syndromes

There are unique challenges in the treatment and prevention of acute coronary syndromes (ACS) with antithrombotics in elderly patients: elderly patients usually require multiple drugs due to comorbidities, are highly susceptible to adverse drug reactions and drug-drug interactions, may have cognitive problems affecting compliance and complications, are especially exposed to the risk of falls and, most importantly, ageing is an independent risk factor for bleeding. Antithrombotic drugs, alone or in association, further and variously amplify age-related bleeding risk. Moreover, age-related changes in primary haemostasis may potentially affect the pharmacodynamics of some antiplatelet drugs. Thus, elderly subjects might be more or less sensitive to standard antiplatelet regimens depending on individual characteristics affecting antiplatelet drug response. Importantly, elderly patients are a rapidly growing population worldwide, have the highest incidence of ACS, but are poorly represented in clinical trials. As a consequence, evidence on antithrombotic drug benefits and risks is limited. Thus, in the real-world setting, older people are often denied antithrombotic drugs because of unjustified concerns, or might be over-treated and exposed to excessive bleeding risk. Personalized antithrombotic therapy in elderly patients is particularly critical, to minimize risks without affecting efficacy.

Impaired Immune Response in Elderly Burn Patients: New Insights Into the Immune-senescence Phenotype

OBJECTIVE

Comparing the inflammatory and immunological trajectories in burned adults versus burned elderly patients to gain novel insights and better understanding why elderly have poor outcomes.

SUMMARY BACKGROUND DATA

Despite receiving the same treatment and clinical consideration as all other burn patients, elderly patients continue to have substantially poorer outcomes compared with adults. In light of an aging population, gaining a better understanding of their susceptibility to complications and creating new treatment strategies is imperative.

METHODS

We included 130 burn patients (94 adults: <65 years old and 36 elderly: ≥65 years old) and 10 healthy controls in this study. Immune activity and expression was assessed using bioplex at various time points. Clinical outcomes such as infection, sepsis, and mortality were prospectively collected.

RESULTS

Elderly burn patients had significantly lower burn size but significantly higher Baux scores. Morbidity and mortality was significantly increased in the elderly cohort. Immune biomarkers indicated that elderly are immune compromised and unable to respond with the expected inflammatory response during the early phase after injury. This trajectory changes to a hyperinflammatory pattern during the later phase after burn. These findings are even more pronounced when comparing sepsis versus nonsepsis patients as well as survivors versus nonsurvivors in the elderly.

CONCLUSIONS

Elderly burned patients mount a delayed immune and dampened inflammatory response early after burn injury that changes to an augmented response at later time points. Late-onset sepsis and nonsurvivors had an immune exhaustion phenotype, which may represent one of the main mediators responsible for the striking mortality in elderly.

Challenges with Diagnosing and Managing Sepsis in Older Adults

Sepsis in older adults has many challenges that affect rate of septic diagnosis, treatment, and monitoring parameters. Numerous age-related changes and comorbidities contribute to increased risk of infections in older adults, but also atypical symptomatology that delays diagnosis. Due to various pharmacokinetic/pharmacodynamic changes in the older adult, medications are absorbed, metabolized, and eliminated at different rates as compared to younger adults, which increases risk of adverse drug reactions due to use of drug therapy needed for sepsis management. This review provides information to aid in diagnosis and offers recommendations for monitoring and treating sepsis in the older adult population.

Biomarkers related to immunosenescence: relationships with therapy and survival in lung cancer patients

PURPOSE

There are well-known alterations occurring within the immune system with aging. Collectively, these changes are known as immunosenescence. The incidence of malignancies also increases with age. The aim of this study was to determine the presence of immunosenescence biomarkers in non-small cell lung cancer (NSCLC) patients and to evaluate some of them as predictive biomarkers of CIMAvax-EGF cancer vaccine efficacy.

METHODS

Sixty-six NSCLC patients, vaccinated or not with CIMAvax-EGF cancer vaccine, and 37 age-matched controls were enrolled. Peripheral blood samples were studied for CD19+, CD4+, CD8+, CD28-, CD57+ and CD45RA+ subpopulations by flow cytometry.

RESULTS

Absolute count of CD19+ and the CD4/CD8 ratio were significantly lower in NSCLC patients than in age-paired controls, while highly differentiated T cells increased in NSCLC patients treated with platinum-based chemotherapy. Using Cox regression, we were able to dichotomize the patient population according to biomarkers. Vaccinated patients with frequency <24 % of CD8 + CD28- T cells, >40 % of CD4 T cells and CD4/CD8 ratio higher than two at the beginning of immunotherapy achieved a 20-month increase in median survival regarding control patients.

CONCLUSIONS

Distribution of lymphocyte subsets was influenced by cancer and chemotherapy in NSCLC patients. CD19 + B cells decrease by cancer disease and not by chemotherapy, and CD28- subpopulations increase by chemotherapy and not by cancer. The proportion of CD8 + CD28- T cells, CD4+ T cells and CD4/CD8 ratio can be used as predictive biomarkers of CIMAvax-EGF efficacy in NSCLC patients and thereby could, be a useful tool for a personalized treatment.

The ageing human B cell repertoire: a failure of selection?

B cells undergo a number of different developmental stages, from initial formation of their B cell receptor (BCR) genes to differentiation into antibody-secreting plasma cells. Because the BCR is vital in these differentiation steps, autoreactive and exogenous antigen binding to the BCR exert critical selection pressures to shape the B cell repertoire. Older people are more prone to infectious disease, less able to respond well to vaccination and more likely to have autoreactive antibodies. Here we review evidence of changes in B cell repertoires in older people, which may be a reflection of age-related changes in B cell selection processes.

Slipping through the Cracks: Linking Low Immune Function and Intestinal Bacterial Imbalance to the Etiology of Rheumatoid Arthritis

Autoimmune diseases (ADs) are considered to be caused by the host immune system which attacks and destroys its own tissue by mistake. A widely accepted hypothesis to explain the pathogenic mechanism of ADs is “molecular mimicry,” which states that antibodies against an infectious agent cross-react with a self-antigen sharing an identical or similar antigenic epitope. However, this hypothesis was most likely established based on misleading antibody assay data largely influenced by intense false positive reactions involved in immunoassay systems. Thus reinvestigation of this hypothesis using an appropriate blocking agent capable of eliminating all types of nonspecific reactions and proper assay design is strongly encouraged. In this review, we discuss the possibility that low immune function may be the fundamental, common defect in ADs, which increases the susceptibility to potential disease causative pathogens located in the gastrointestinal tract (GI), such as bacteria and their components or dietary components. In addition to these exogenous agents, aberrations in the host's physical condition may disrupt the host defense system, which is tightly orchestrated by “immune function,” “mucosal barrier function,” and “intestinal bacterial balance.” These disturbances may initiate a downward spiral, which can lead to chronic health problems that will evolve to an autoimmune disorder.

Lymphocyte Subsets in a Population of Nonfrail Elderly Individuals

Age-related frailty is characterized by increased vulnerability to stress due to decline in homeostatic reserve, which results in increased risk of adverse health outcomes including disability, hospitalization, and death. The relationship between frailty and immunological system alterations is well established. Thus, analysis of immunological changes, such as alterations in lymphocyte subsets, during senescence may provide useful markers for frailty and associated pathologies. Since reference ranges currently used for lymphocyte subsets do not specifically differentiate the elderly group, the aim of this study was to (1) establish reference ranges in nonfrail elderly individuals and (2) assess the evolution of these parameters with age. Further, the influence of other physiological and lifestyle factors was also evaluated. The study was performed on 144 elderly individuals (aged 65-95) from Galicia (in northwestern Spain). Percentages of lymphocyte subpopulations (CD3(+) T lymphocytes, CD4(+) T-helper lymphocytes, CD8(+) T-cytotoxic lymphocytes, CD19(+) B lymphocytes, and CD56(+)16(+) natural killer cells) were analyzed in peripheral blood by flow cytometry, and reference ranges were calculated. The individual status as nonfrail or prefrail did not markedly affect the immunological parameters, but an apparent influence of age was obtained for %CD3(+), %CD4(+), and %CD19(+) cells, all of which fell with increasing age. Women showed higher levels of %CD19(+) lymphocytes. No significant influence of smoking habits, physical activity, or drinking alcohol or caffeine beverages was observed. The results obtained may serve as a basis to establish comparisons between frail and nonfrail elderly individuals, in order to determine the usefulness of lymphocyte subsets as immunological biomarkers of frailty.

Plasma cell numbers decrease in bone marrow of old patients

The BM is well understood to play a key role in plasma cell homing and survival in mice. In humans, BM plasma cells and their functions are less well characterized. In this study, we used paired bone biopsies from the femur shaft and blood samples from persons of different ages to analyze age-related changes of plasma and memory B cells. Our results demonstrated that plasma cells were mainly located in the BM, while a higher percentage of memory B cells was in the peripheral blood than in the BM. The frequency of plasma and memory B cells from both sources decreased with age, while immature and naïve B cells were unaffected. An age-related decline of tetanus- and diphtheria-specific BM plasma cells was observed, whereas influenza A- and cytomegalovirus-specific BM plasma cells were not affected. With the exception of cytomegalovirus, peripheral antibody concentrations correlated with BM plasma cells of the same specificity, but were independent of antigen-specific peripheral blood memory B cells. Our results demonstrate that the BM houses decreased numbers of plasma cells in old age. The number of cells of certain specificity may reflect the number and time point of previous antigen encounters and intrinsic age-related changes in the BM.

Peripheral residence of naïve CD4 T cells induces MHC class II-dependent alterations in phenotype and function

BACKGROUND

As individual naïve CD4 T lymphocytes circulate in the body after emerging from the thymus, they are likely to have individually varying microenvironmental interactions even in the absence of stimulation via specific target recognition. It is not clear if these interactions result in alterations in their activation, survival and effector programming. Naïve CD4 T cells show unimodal distribution for many phenotypic properties, suggesting that the variation is caused by intrinsic stochasticity, although underlying variation due to subsets created by different histories of microenvironmental interactions remains possible. To explore this possibility, we began examining the phenotype and functionality of naïve CD4 T cells differing in a basic unimodally distributed property, the CD4 levels, as well as the causal origin of these differences.

RESULTS

We examined separated CD4hi and CD4lo subsets of mouse naïve CD4 cells. CD4lo cells were smaller with higher CD5 levels and lower levels of the dual-specific phosphatase (DUSP)6-suppressing micro-RNA miR181a, and responded poorly with more Th2-skewed outcomes. Human naïve CD4lo and CD4hi cells showed similar differences. Naïve CD4lo and CD4hi subsets of thymic single-positive CD4 T cells did not show differences whereas peripheral naïve CD4lo and CD4hi subsets of T cell receptor (TCR)-transgenic T cells did. Adoptive transfer-mediated parking of naïve CD4 cells in vivo lowered CD4 levels, increased CD5 and reactive oxygen species (ROS) levels and induced hyporesponsiveness in them, dependent, at least in part, on availability of major histocompatibility complex class II (MHCII) molecules. ROS scavenging or DUSP inhibition ameliorated hyporesponsiveness. Naïve CD4 cells from aged mice showed lower CD4 levels and cell sizes, higher CD5 levels, and hyporesponsiveness and Th2-skewing reversed by DUSP inhibition.

CONCLUSIONS

Our data show that, underlying a unimodally distributed property, the CD4 level, there are subsets of naïve CD4 cells that vary in the time spent in the periphery receiving MHCII-mediated signals and show resultant alteration of phenotype and functionality via ROS and DUSP activity. Our findings also suggest the feasibility of potential pharmacological interventions for improved CD4 T cell responses during vaccination of older people via either anti-oxidant or DUSP inhibitor small molecules.