Immunosenescence, autoimmunity, and rheumatoid arthritis

Immunosenescence and Cytomegalovirus: Exploring Their Connection in the Context of Aging, Health, and Disease

Aging induces numerous physiological alterations, with immunosenescence emerging as a pivotal factor. This phenomenon has attracted both researchers and clinicians, prompting profound questions about its implications for health and disease. Among the contributing factors, one intriguing actor in this complex interplay is human cytomegalovirus (CMV), a member of the herpesvirus family. Latent CMV infection exerts a profound influence on the aging immune system, potentially contributing to age-related diseases. This review delves into the intricate relationship between immunosenescence and CMV, revealing how chronic viral infection impacts the aging immune landscape. We explore the mechanisms through which CMV can impact both the composition and functionality of immune cell populations and induce shifts in inflammatory profiles with aging. Moreover, we examine the potential role of CMV in pathologies such as cardiovascular diseases, cancer, neurodegenerative disorders, COVID-19, and Long COVID. This review underlines the importance of understanding the complex interplay between immunosenescence and CMV. It offers insights into the pathophysiology of aging and age-associated diseases, as well as COVID-19 outcomes among the elderly. By unraveling the connections between immunosenescence and CMV, we gain a deeper understanding of aging's remarkable journey and the profound role that viral infections play in transforming the human immune system.

From aging to long COVID: exploring the convergence of immunosenescence, inflammaging, and autoimmunity

The process of aging is accompanied by a dynamic restructuring of the immune response, a phenomenon known as immunosenescence. This mini-review navigates through the complex landscape of age-associated immune changes, chronic inflammation, age-related autoimmune tendencies, and their potential links with immunopathology of Long COVID. Immunosenescence serves as an introductory departure point, elucidating alterations in immune cell profiles and their functional dynamics, changes in T-cell receptor signaling, cytokine network dysregulation, and compromised regulatory T-cell function. Subsequent scrutiny of chronic inflammation, or "inflammaging," highlights its roles in age-related autoimmune susceptibilities and its potential as a mediator of the immune perturbations observed in Long COVID patients. The introduction of epigenetic facets further amplifies the potential interconnections. In this compact review, we consider the dynamic interactions between immunosenescence, inflammation, and autoimmunity. We aim to explore the multifaceted relationships that link these processes and shed light on the underlying mechanisms that drive their interconnectedness. With a focus on understanding the immunological changes in the context of aging, we seek to provide insights into how immunosenescence and inflammation contribute to the emergence and progression of autoimmune disorders in the elderly and may serve as potential mediator for Long COVID disturbances.

Prognostic factors for primary diff use large B-cell lymphoma of the brain

OBJECTIVE

Diffuse large B-cell lymphoma (DLBCL) is the most common histopathological type of non-Hodgkin's lymphoma and might arise from various extranodal sites. Little is known about the clinical characteristics and survival outcomes of primary DLBCL of the brain, including the cerebrum, cerebellum, brain steam and ventricle (CCSV). Thus, we performed this study to explore the independent prognostic factors of CCSV-DLBCL using the Surveillance, Epidemiology, and End Results (SEER) database.

MATERIALS AND METHODS

We extracted the data of patients diagnosed with CCSV-DLBCL between 1975 and 2016 from the SEER database. Variables including demographic characteristics, Ann Arbor stage and therapies, such as surgery, radiation and chemotherapy, were all collected. The prognostic factors on overall survival (OS) and disease-specific survival (DSS) were analysed using Kaplan-Meier curves.

RESULTS

One thousand three hundred and twenty-eight patients were finally enrolled in the analysis. The median age was 62 years old. More than half of the cases of CCSV-DLBCL (54.22%) originated from the cerebrum. Patients older than 75 years had the worst OS and DSS. Moreover, black people had the worst survival outcomes compared with white and other people. Surgery, radiation and chemotherapy all significantly improved OS and DSS.

CONCLUSION

To the best of our knowledge, this is the largest population-based study of CCSV-DLBCL. Advanced age, black race, lack of surgical resection, radiation or chemotherapy were all poor prognostic factors.

Senescent T cells: Beneficial and detrimental roles

As the thymus involutes during aging, the T-cell pool has to be maintained by the periodic expansion of preexisting T cells during adulthood. A conundrum is that repeated episodes of activation and proliferation drive the differentiation of T cells toward replicative senescence, due to telomere erosion. This review discusses mechanisms that regulate the end-stage differentiation (senescence) of T cells. Although these cells, within both CD4 and CD8 compartments, lose proliferative activity after antigen-specific challenge, they acquire innate-like immune function. While this may confer broad immune protection during aging, these senescent T cells may also cause immunopathology, especially in the context of excessive inflammation in tissue microenvironments.

Insights from a Case of Good's Syndrome (Immunodeficiency with Thymoma)

Immunodeficiency with thymoma was described by R.A. Good in 1954 and is also named after him. The syndrome is characterized by hypogammaglobulinemia associated with thymoma and recurrent infections, bacterial but also viral, fungal and parasitic. Autoimmune diseases, mainly pure red cell aplasia, other hematological disorders and erosive lichen planus are a common finding. We describe here a typical case exhibiting all these clinical features and report a detailed immunophenotypic assessment, as well as the positivity for autoantibodies against three cytokines (IFN-alpha, IL-6 and GM-CSF), which may add to known immune abnormalities. A review of the published literature, based on case series and immunological studies, offers some hints on the still unsolved issues of this rare condition.

Mitochondria as disease-relevant organelles in rheumatoid arthritis

Mitochondria are the controllers of cell metabolism and are recognized as decision makers in cell death pathways, organizers of cytoplasmic signaling networks, managers of cellular stress responses, and regulators of nuclear gene expression. Cells of the immune system are particularly dependent on mitochondrial resources, as they must swiftly respond to danger signals with activation, trafficking, migration, and generation of daughter cells. Analogously, faulty immune responses that lead to autoimmunity and tissue inflammation rely on mitochondria to supply energy, cell building blocks and metabolic intermediates. Emerging data endorse the concept that mitochondrial fitness, and the lack of it, is of particular relevance in the autoimmune disease rheumatoid arthritis (RA) where deviations of bioenergetic and biosynthetic flux affect T cells during early and late stages of disease. During early stages of RA, mitochondrial deficiency allows naïve RA T cells to lose self-tolerance, biasing fundamental choices of the immune system toward immune-mediated tissue damage and away from host protection. During late stages of RA, mitochondrial abnormalities shape the response patterns of RA effector T cells engaged in the inflammatory lesions, enabling chronicity of tissue damage and tissue remodeling. In the inflamed joint, autoreactive T cells partner with metabolically reprogrammed tissue macrophages that specialize in antigen-presentation and survive by adapting to the glucose-deplete tissue microenvironment. Here, we summarize recent data on dysfunctional mitochondria and mitochondria-derived signals relevant in the RA disease process that offer novel opportunities to deter autoimmune tissue inflammation by metabolic interference.

Pathogenesis of giant cell arteritis with focus on cellular populations

Giant cell arteritis (GCA), the most common non-infectious vasculitis, mainly affects elderly individuals. The disease usually affects the aorta and its main supra-aortic branches causing both general symptoms of inflammation and specific ischemic symptoms because of the limited blood flow due to arterial structural changes in the inflamed arteries. The pathogenesis of the GCA is complex and includes a dysregulated immune response that affects both the innate and the adaptive immunity. During the last two decades several studies have investigated interactions among antigen-presenting cells and lymphocytes, which contribute to the formation of the inflammatory infiltrate in the affected arteries. Toll-like receptor signaling and interactions through the VEGF-Notch-Jagged1 pathway are emerging as crucial events of the aberrant inflammatory response, facilitating among others the migration of inflammatory cells to the inflamed arteries and their interactions with the local stromal milieu. The increased use of checkpoint inhibitors in cancer immunotherapy and their immune-related adverse events has fed interest in the role of checkpoint dysfunction in GCA, and recent studies suggest a dysregulated check point system which is unable to suppress the inflammation in the previously immune-privileged arteries, leading to vasculitis. The role of B-cells is currently reevaluated because of new reports of considerable numbers of plasma cells in inflamed arteries as well as the formation of artery tertiary lymphoid organs. There is emerging evidence on previously less studied cell populations, such as the neutrophils, CD8+ T-cells, T regulatory cells and tissue residing memory cells as well as for stromal cells which were previously considered as innocent bystanders. The aim of this review is to summarize the evidence in the literature regarding the cell populations involved in the pathogenesis of GCA and especially in the context of an aged, immune system.

Macrophages and glial cells: Innate immune drivers of inflammatory arthritic pain perception from peripheral joints to the central nervous system

Millions of people suffer from arthritis worldwide, consistently struggling with daily activities due to debilitating pain evoked by this disease. Perhaps the most intensively investigated type of inflammatory arthritis is rheumatoid arthritis (RA), where, despite considerable advances in research and clinical management, gaps regarding the neuroimmune interactions that guide inflammation and chronic pain in this disease remain to be clarified. The pain and inflammation associated with arthritis are not isolated to the joints, and inflammatory mechanisms induced by different immune and glial cells in other tissues may affect the development of chronic pain that results from the disease. This review aims to provide an overview of the state-of-the-art research on the roles that innate immune, and glial cells play in the onset and maintenance of arthritis-associated pain, reviewing nociceptive pathways from the joint through the dorsal root ganglion, spinal circuits, and different structures in the brain. We will focus on the cellular mechanisms related to neuroinflammation and pain, and treatments targeting these mechanisms from the periphery and the CNS. A comprehensive understanding of the role these cells play in peripheral inflammation and initiation of pain and the central pathways in the spinal cord and brain will facilitate identifying new targets and pathways to aide in developing therapeutic strategies to treat joint pain associated with RA.

Age-associated phenotypic imbalance in TCD4 and TCD8 cell subsets: comparison between healthy aged, smokers, COPD patients and young adults

Background

COPD is associated with an abnormal lung immune response that leads to tissue damage and remodeling of the lung, but also to systemic effects that compromise immune responses. Cigarette smoking also impacts on innate and adaptative immune responses, exerting dual, pro- and anti-inflammatory effects. Previously, we showed that COPD patients presented accelerated telomere shortening and decreased telomerase activity, while, paradoxically, cigarette-smokers exhibited preserved telomerase activity and slower rate of telomere shortening.

Results

Here, we evaluated the naive, CM, EM and TEMRA subsets of TCD4 and TCD8 cells according to the expression of CCR7/CD45RA. We compared age-matched COPD patients, cigarette-smokers without clinical-laboratory evidence of pulmonary compromise, and healthy individuals. They were additionally compared with a group of young adults. For each subset we analysed the expression of markers associated with late differentiation, senescence and exhaustion (CD27/CD28/CD57/KLRG1/PD1). We show that COPD patients presented a drastically reduced naive cells pool, and, paradoxically, increased fractions of naive cells expressing late differentiation, senescence or exhaustion markers, likely impacting on their immunocompetence. Pronounced phenotypic alterations were also evidenced in their three memory T-cell subsets compared with the other aged and young groups, suggesting an also dysfunctional memory pool. Surprisingly, our smokers showed a profile closer to the Healthy aged than COPD patients. They exhibited the usual age-associated shift of naive to EM TCD4 and TCD8 cells, but not to CM or TEMRA T-cells. Nonetheless, their naive T-cells phenotypes were in general similar to those of the Youngs and Healthy aged, suggesting a rather phenotypically preserved subset, while the memory T-cells exhibited increased proportions of cells with the late-differentiation or senescence/exhaustion markers as in the Healthy aged.

Conclusion

Our study extends previous findings by showing that COPD patients have cells expressing a full range of late differentiated, senescent or exhausted phenotypes encompassing all TCD4 and TCD8 subsets, consistent with a premature immunosenescence phenotype. Surprisingly, the smokers group’s results suggest that moderate to heavy chronic cigarette smoking did not accelerate the pace of immunosenescence as compared with the Healthy aged.

Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) Spectroscopy Discriminates the Elderly with a Low and High Percentage of Pathogenic CD4+ T Cells

In the aging process, the presence of interleukin (IL)-17-producing CD4+CD28-NKG2D+T cells (called pathogenic CD4+ T cells) is strongly associated with inflammation and the development of various diseases. Thus, their presence needs to be monitored. The emergence of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy empowered with machine learning is a breakthrough in the field of medical diagnostics. This study aimed to discriminate between the elderly with a low percentage (LP; ≤3%) and a high percentage (HP; ≥6%) of pathogenic CD4+CD28-NKG2D+IL17+ T cells by utilizing ATR-FTIR coupled with machine learning algorithms. ATR spectra of serum, exosome, and HDL from both groups were explored in this study. Only exosome spectra in the 1700-1500 cm-1 region exhibited possible discrimination for the LP and HP groups based on principal component analysis (PCA). Furthermore, partial least square-discriminant analysis (PLS-DA) could differentiate both groups using the 1700-1500 cm-1 region of exosome ATR spectra with 64% accuracy, 69% sensitivity, and 61% specificity. To obtain better classification performance, several spectral models were then established using advanced machine learning algorithms, including J48 decision tree, support vector machine (SVM), random forest (RF), and neural network (NN). Herein, NN was considered to be the best model with an accuracy of 100%, sensitivity of 100%, and specificity of 100% using serum spectra in the region of 1800-900 cm-1. Exosome spectra in the 1700-1500 and combined 3000-2800 and 1800-900 cm-1 regions using the NN algorithm gave the same accuracy performance of 95% with a variation in sensitivity and specificity. HDL spectra with the NN algorithm also showed excellent test performance in the 1800-900 cm-1 region with 97% accuracy, 100% sensitivity, and 95% specificity. This study demonstrates that ATR-FTIR coupled with machine learning algorithms can be used to study immunosenescence. Furthermore, this approach can possibly be applied to monitor the presence of pathogenic CD4+ T cells in the elderly. Due to the limited number of samples used in this study, it is necessary to conduct a large-scale study to obtain more robust classification models and to assess the true clinical diagnostic performance.

Th17/IL-17 induces endothelial cell senescence via activation of NF-κB/p53/Rb signaling pathway

Cellular senescence is a key mechanism of age-related vascular endothelial dysfunction. Interleukin-17A (IL-17A) is an inflammatory cytokine produced by Th17 cells (a subgroup of helper T cells), which is a key factor in the development of atherosclerosis. However, the effect of IL-17A on the senescence of vascular endothelial cells is still unclear. In this study, we aimed to explore the role of IL-17A on endothelial cell senescence and its signaling pathways associated with senescence. The proportion of Th17 cells in the spleen and the expression levels of IL-17A, IL-6, and vascular cell adhesion molecule-1 (VCAM-1) in mice of different ages were increased with aging. In vitro experiments showed that proliferation was inhibited, senescent β-galactosidase and senescence-associated proteins (p16, p19, p21, and p53) of mouse aortic endothelial cells (MAECs) were increased with IL-17A treatment. Blocking the NF-κB pathway with ammonium pyrrolidinedithiocarbamate (PDTC) successfully inhibited IL-17A-induced expression of senescence-associated proteins. In conclusion, our data reveal a previously unsuspected link between IL-17A and endothelial cell senescence, which was mediated by the NF-κB /p53/Rb pathway.

Primary Diffuse Large B-Cell Lymphoma of the Urinary Tract: A Population-Based Analysis

Objective

Diffuse large B-cell lymphoma (DLBCL) is the most common histopathological type of non-Hodgkin’s lymphoma, which may arise from various extranodal sites. Little is known about the clinical characteristics and survival outcomes of primary DLBCL of the urinary tract (UT). Thus, we conducted this study to explore the independent prognostic factors of patients with UT-DLBCL using the Surveillance, Epidemiology, and End Results (SEER) database.

Materials and Methods

We searched the Surveillance, Epidemiology, and End Results (SEER) database for the data of patients diagnosed with UT-DLBCL between 1975 and 2016. Data, including demographic tumour stage and therapeutic strategies, such as surgical resection, radiation therapy, and chemotherapy, were collected. The impact of these factors on survival outcomes, including overall survival (OS) and disease-specific survival (DSS), was analysed using Kaplan–Meier curves.

Results

Four-hundred and eighty-nine patients who met the inclusion criteria were enrolled in the data analysis. The median age was 69 years old. Most cases of UT-DLBCL (72.39%) originated from the kidney, followed by the urinary bladder (24.95%). Both surgical resection and chemotherapy can significantly improve OS and DSS. Patients older than 75 years had the worst survival outcomes. Stage IV DLBCL may be a poor prognostic factor.

Conclusion

To the best of our knowledge, this is the largest population-based study of UT-DLBCL. Advanced age, male gender, lack of surgical resection or chemotherapy, and stage IV DLBCL were poor prognostic factors.

Lymphopenia, Lymphopenia-Induced Proliferation, and Autoimmunity

Immune homeostasis is a tightly regulated system that is critical for defense against invasion by foreign pathogens and protection from self-reactivity for the survival of an individual. How the defects in this system might result in autoimmunity is discussed in this review. Reduced lymphocyte number, termed lymphopenia, can mediate lymphopenia-induced proliferation (LIP) to maintain peripheral lymphocyte numbers. LIP not only occurs in normal physiological conditions but also correlates with autoimmunity. Of note, lymphopenia is also a typical marker of immune aging, consistent with the fact that not only the autoimmunity increases in the elderly, but also autoimmune diseases (ADs) show characteristics of immune aging. Here, we discuss the types and rates of LIP in normal and autoimmune conditions, as well as the coronavirus disease 2019 in the context of LIP. Importantly, although the causative role of LIP has been demonstrated in the development of type 1 diabetes and rheumatoid arthritis, a two-hit model has suggested that the factors other than lymphopenia are required to mediate the loss of control over homeostasis to result in ADs. Interestingly, these factors may be, if not totally, related to the function/number of regulatory T cells which are key modulators to protect from self-reactivity. In this review, we summarize the important roles of lymphopenia/LIP and the Treg cells in various autoimmune conditions, thereby highlighting them as key therapeutic targets for autoimmunity treatments.

The immunology of rheumatoid arthritis

The immunopathogenesis of rheumatoid arthritis (RA) spans decades, beginning with the production of autoantibodies against post-translationally modified proteins (checkpoint 1). After years of asymptomatic autoimmunity and progressive immune system remodeling, tissue tolerance erodes and joint inflammation ensues as tissue-invasive effector T cells emerge and protective joint-resident macrophages fail (checkpoint 2). The transition of synovial stromal cells into autoaggressive effector cells converts synovitis from acute to chronic destructive (checkpoint 3). The loss of T cell tolerance derives from defective DNA repair, causing abnormal cell cycle dynamics, telomere fragility and instability of mitochondrial DNA. Mitochondrial and lysosomal anomalies culminate in the generation of short-lived tissue-invasive effector T cells. This differentiation defect builds on a metabolic platform that shunts glucose away from energy generation toward the cell building and motility programs. The next frontier in RA is the development of curative interventions, for example, reprogramming T cell defects during the period of asymptomatic autoimmunity.

Emergence of T cell immunosenescence in diabetic chronic kidney disease

Background

Type 2 diabetes is an important challenge given the worldwide epidemic and is the most important cause of end-stage renal disease (ESRD) in developed countries. It is known that patients with ESRD and advanced renal failure suffer from immunosenescence and premature T cell aging, but whether such changes develop in patients with less severe chronic kidney disease (CKD) is unclear.

Method

523 adult patients with type 2 diabetes were recruited for this study. Demographic data and clinical information were obtained from medical chart review. Immunosenescence, or aging of the immune system was assessed by staining freshly-obtained peripheral blood with immunophenotyping panels and analyzing cells using multicolor flow cytometry.

Result

Consistent with previously observed in the general population, both T and monocyte immunosenescence in diabetic patients positively correlate with age. When compared to diabetic patients with preserved renal function (estimated glomerular filtration rate > 60 ml/min), patients with impaired renal function exhibit a significant decrease of total CD3⁺ and CD4⁺ T cells, but not CD8⁺ T cell and monocyte numbers. Immunosenescence was observed in patients with CKD stage 3 and in patients with more severe renal failure, especially of CD8⁺ T cells. However, immunosenescence was not associated with level of proteinuria level or glucose control. In age, sex and glucose level-adjusted regression models, stage 3 CKD patients exhibited significantly elevated percentages of CD28^-, CD127^-, and CD57⁺ cells among CD8⁺ T cells when compared to patients with preserved renal function. In contrast, no change was detected in monocyte subpopulations as renal function declined. In addition, higher body mass index (BMI) is associated with enhanced immunosenescence irrespective of CKD status.

Conclusion

The extent of immunosenescence is not significantly associated with proteinuria or glucose control in type 2 diabetic patients. T cells, especially the CD8⁺ subsets, exhibit aggravated characteristics of immunosenescence during renal function decline as early as stage 3 CKD. In addition, inflammation increases since stage 3 CKD and higher BMI drives the accumulation of CD8⁺CD57⁺ T cells. Our study indicates that therapeutic approaches such as weight loss may be used to prevent the emergence of immunosenescence in diabetes before stage 3 CKD.

Treatment-resistant synovitis and radiographic progression are increased in elderly-onset rheumatoid arthritis patients: findings from a prospective observational longitudinal early arthritis cohort study

BACKGROUND

Clinical outcomes in elderly-onset rheumatoid arthritis (EORA), starting after the age of 60, are conflicting. Thus, we aimed to investigate in a unique biopsy-driven, treatment-naïve early arthritis cohort, the relationship between synovial pathobiology of elderly- (EORA) and younger-onset rheumatoid arthritis (YORA) patients through clinical, imaging and treatment response outcome-measures.

METHODS

Patients (n = 140) with early RA (<12months) starting before (YORA, n = 99) or after (EORA, n = 41) age 60 had an ultrasound-guided synovial biopsy prior to conventional immunosuppressive therapy and after 6 months. Clinical, ultrasound and radiographic data were collected prospectively and compared between groups and against immunohistological features. Using multivariate logistic regression, we determined predictors of clinical response (disease activity score-28-erythrocyte sedimentation rate [DAS28-ESR]<3.2) at 6 months and radiographic progression (≥1-unit-increase in Sharp van der Heijde [SvdH] score) at 12 months.

RESULTS

EORA patients were more frequently male and presented most commonly with an abrupt, polymyalgia rheumatica-like onset and extra-articular features. Both before and after treatment, DAS28-ESR was similar but ultrasound synovial-thickening (p<0.05) and power-Doppler (p<0.01) synovitis and SvdH (p<0.001) scores were higher in EORA patients. EORA was independently associated with poor treatment response at 6 months (OR=0.28, p = 0.047) and radiographic progression at 12 months (OR=4.08, p = 0.029). Synovial pathotype, synovitis scores and cellular infiltration were similar before treatment, but a pauci-immune-fibroid pathotype tended to be more common in YORA at 6 months (p = 0.093). Moreover, YORA patients had a marked improvement of all synovitis parameters (p<0.001), whereas EORA presented only mild decreases in synovitis (p<0.05), sublining macrophage (p<0.05) and T cell scores (p<0.05), with no significant changes in lining macrophages, B cells or plasma cells.

CONCLUSION

Early EORA presents differently and has a worse overall prognosis than YORA, with poorer clinical, histological, ultrasonographic and radiographic outcomes.

Role of the Nuclear Lamina in Age-Associated Nuclear Reorganization and Inflammation

Aging is characterized by the gradual loss of tissue function and integrity. Activation of inflammatory responses accelerates the deterioration of cells and tissues. Many studies have shown that alteration of the components of the nuclear lamina is associated with inflammation, both in vivo and in vitro. However, the mechanism by which the nuclear lamina regulates inflammation is largely unknown. Recent studies have suggested that the nuclear lamina regulates both organization of the three-dimensional chromatin structure at the nuclear periphery and global gene expression, such as the expression of inflammatory response genes. Here, we discuss the current updates in the research on nuclear lamina alteration, activation of inflammation, and nuclear reorganization in models of cellular senescence and organismal aging.

Characterization of senescence biomarkers in rheumatoid arthritis: relevance to disease progression

Rheumatoid arthritis (RA) has been associated with early senescent features. However, the effects of disease progression on senescence markers are largely unknown. Here, we evaluated key senescence markers in RA, including telomere length and T cell differentiation stages as well as cytomegalovirus (CMV) serology, previously associated with premature aging. In a cross-sectional study, 44 patients with active (Ac-RA), 26 patients with controlled (Co-RA), and 30 healthy controls were recruited. Peripheral blood was collected and differentiation stages of T cells analyzed by multi-color flow cytometry. Enzyme-linked immunosorbent assays were used to evaluate the CMV serology. The telomere length was measured by multiplex quantitative PCR. Patients with Ac-RA presented lower percentage of intermediate-differentiated T cells (CD4+CD27-CD28+ and CD8+CD27-CD28+; p < 0.001). All patients had a reduced proportion of cytotoxic T cells, and higher CD4/CD8 ratio compared with controls (p < 0.001). A lower proportion of CMV IgG+ subjects was found in the Co-RA group, (P < 0.001), although no differences in the CMV IgG titers were observed between groups. The groups had similar leukocyte telomere length. In addition, age was negatively correlated with CD8+CD27+CD28+ T (early-differentiated) cells (P < 0.05). Positive correlations between CMV IgG titers and age (P < 0.05) and CD4+CD27-CD28- T (late-differentiated) cells (P < 0.01) were observed. Furthermore, disease duration was correlated with CD4+CD27+CD28+ T cells (r = - 0.318, p < 0.05) and CD4+CD27-CD28- T cells (r = 0.308, p < 0.05). Our findings indicate that CMV and age may have a similar impact on T cells in both RA patients and controls. KEY POINTS: • Patients and controls were homogenous regarding CMV IgG titers and TL. • A lower proportion of CMV IgG+ subjects was found in the Co-RA group. • Anti-CMV levels were positively correlated with age and percentage of CD4+CD27-CD28- (late-differentiated) T cells.

The immunoinhibitory PD-1/PD-L1 pathway in inflammatory blood vessel disease

Because of their vital function, the wall structures of medium and large arteries are immunoprivileged and protected from inflammatory attack. That vascular immunoprivilege is broken in atherosclerosis and in vasculitis, when wall-invading T cells and macrophages (Mϕ) promote tissue injury and maladaptive repair. Historically, tissue-residing T cells were studied for their antigen specificity, but recent progress has refocused attention to antigen-nonspecific regulation, which determines tissue access, persistence, and functional differentiation of T cells. The coinhibitory receptor PD-1, expressed on T cells, delivers negative signals when engaged by its ligand PD-L1, expressed on dendritic cells, Mϕ, and endothelial cells to attenuate T cell activation, effector functions, and survival. Through mitigating signals, the PD-1 immune checkpoint maintains tissue tolerance. In line with this concept, dendritic cells and Mϕs from patients with the vasculitic syndrome giant cell arteritis (GCA) are PD-L1^lo ; including vessel-wall-embedded DCs that guard the vascular immunoprivilege. GCA infiltrates in the arterial walls are filled with PD-1⁺ T cells that secrete IFN-γ, IL-17, and IL-21; drive inflammation-associated angiogenesis; and facilitate intimal hyperplasia. Conversely, chronic tissue inflammation in the atherosclerotic plaque is associated with an overreactive PD-1 checkpoint. Plaque-residing Mϕs are PD-L1^hi , a defect induced by their addiction to glucose and glycolytic breakdown. PD-L1^hi Mϕs render patients with coronary artery disease immunocompromised and suppress antiviral immunity, including protective anti-varicella zoster virus T cells. Thus, immunoinhibitory signals affect several domains of vascular inflammation; failing PD-L1 in vasculitis enables unopposed immunostimulation and opens the flood gates for polyfunctional inflammatory T cells, and excess PD-L1 in the atherosclerotic plaque disables tissue-protective T cell immunity.

Ovarian aging is associated with gray matter volume and disability in women with MS

OBJECTIVE

To determine if ovarian aging as measured by levels of anti-Müllerian hormone (AMH) is associated with pattern of multiple sclerosis (MS) progression in women.

METHODS

Women with MS and healthy controls were included from a longitudinal research cohort with up to 10 years follow-up. Plasma AMH levels were measured by ELISA for baseline and years 3, 5, and 8-10. Mixed effects logistic and linear regression models were employed, with adjustments for age, disease duration, and other covariables as appropriate.

RESULTS

AMH levels were similar (0.98-fold difference, 95% confidence interval [CI] 0.69-1.37, p = 0.87) in women with MS (n = 412, mean age 42.6 years) and healthy controls (n = 180, mean age 44 years). In a multivariable model of women with MS, including adjustments for age, body mass index, and disease duration, 10-fold lower AMH level was associated with 0.43-higher Expanded Disability Status Scale (EDSS) score (95% CI 0.15-0.70, p = 0.003), 0.25-unit worse MS Functional Composite z score (95% CI -0.40 to -0.10, p = 0.0015), and 7.44 mm³ lower cortical gray matter volume (95% CI -14.6 to -0.30; p = 0.041) at baseline. In a multivariable random-intercept-random-slope model using all observations over time, 10-fold decrease in AMH was associated with a 0.27 increase in EDSS (95% CI 0.11-0.43, p = 0.006) and 5.48 mm³ (95% CI 11.3-0.33, p = 0.065) and 4.55 mm³ (95% CI 9.33-0.23, p = 0.062) decreases in total gray and cortical gray matter, respectively.

CONCLUSION

As a marker of ovarian aging, lower AMH levels were associated with greater disability and gray matter loss in women with MS independent of chronological age and disease duration.

Aging, Obesity, and Inflammatory Age-Related Diseases

The increase in the prevalence of obesity represents a worldwide phenomenon in all age groups and is pathologically and genetically correlated with several metabolic and cardiovascular diseases, representing the most frequent age-related diseases. Obesity superimposed on aging drastically increases chronic low-grade inflammation (inflammaging), which is an important link between obesity, insulin resistance, and age-associated diseases. Immune cells of both the innate and the adaptive immune systems infiltrate the adipose tissue (AT) and during obesity induce inflammatory responses associated with metabolic switches and changes in phenotypes and function of immune cell subsets. Obesity poses new health problems especially when it occurs in the context of other diseases, many of them frequently affect elderly subjects. An emerging problem is the decreased proportion of patients with obesity achieving clinical response to therapy. In this review, we will discuss the reciprocal influences of immune cell and AT inflammation in aging and age-associated diseases and the complex relationship of nutrient and energy-sensing homeostatic checkpoints, which contribute to shape the phenotype of the AT. We will specifically examine type-2 diabetes, rheumatoid arthritis, osteoarthritis, cognitive impairment, and dementia, where obesity plays a significant role, also in shaping some clinical aspects.

Right drug, right patient, right time: aspiration or future promise for biologics in rheumatoid arthritis?

Individualising biologic disease-modifying anti-rheumatic drugs (bDMARDs) to maximise outcomes and deliver safe and cost-effective care is a key goal in the management of rheumatoid arthritis (RA). Investigation to identify predictive tools of bDMARD response is a highly active and prolific area of research. In addition to clinical phenotyping, cellular and molecular characterisation of synovial tissue and blood in patients with RA, using different technologies, can facilitate predictive testing. This narrative review will summarise the literature for the available bDMARD classes and focus on where progress has been made. We will also look ahead and consider the increasing use of 'omics' technologies, the potential they hold as well as the challenges, and what is needed in the future to fully realise our ambition of personalised bDMARD treatment.

Chronic Inflammation: Accelerator of Biological Aging

Biological aging is characterized by a chronic low-grade inflammation level. This chronic phenomenon has been named "inflamm-aging" and is a highly significant risk factor for morbidity and mortality in the older persons. The most common theories of inflamm-aging include redox stress, mitochondrial dysfunction, glycation, deregulation of the immune system, hormonal changes, epigenetic modifications, and dysfunction telomere attrition. Inflamm-aging plays a role in the initiation and progression of age-related diseases such as type II diabetes, Alzheimer's disease, cardiovascular disease, frailty, sarcopenia, osteoporosis, and cancer. This review will cover the identification of pathways that control age-related inflammation across multiple systems and its potential causal role in contributing to adverse health outcomes.

mRNA profiling identifies low levels of phosphatases dual‐specific phosphatase‐7 (DUSP7) and cell division cycle‐25B (CDC25B) in patients with early arthritis

Phosphotyrosine phosphatases (PTPs) control phosphorylation levels and, consequently, regulate the output of intracellular signalling networks in health and disease. Despite the high number of PTPs expressed in CD4 T cells and their involvement in autoimmunity, information about the expression profile of PTPs in these cells has not been obtained in patients diagnosed with autoimmune diseases. Here, we compare the expression profile of PTPs in CD4 T cells of healthy volunteers and patients submitted to an early arthritis clinic, due to suspicion of rheumatoid arthritis, an autoimmune disease mediated by CD4 T cells. We found lower transcript levels of the mitogen-activated protein kinase (MAPK) phosphatase dual-specific phosphatase-7 (DUSP7) and the cell division cycle-25B (CDC25B) in T cells of patients. While the low expression level of DUSP7 was restricted to patients with positive rheumatoid factor and anti-citrullinated protein antibodies, the altered expression of CDC25B correlated with the activity of the disease. Low levels of CDC25B might contribute to the progression of the autoimmune arthritis and/or might be consequence of the inflammatory environment in the active disease. The possible role of DUSP7 and CDC25B as biomarkers of the disease in clinical protocols is discussed.

Interactions between immune challenges and cancer cells proliferation: timing does matter!

The immune system is a key component of malignant cell control and it is also involved in the elimination of pathogens that threaten the host. Despite our body is permanently exposed to a myriad of pathogens, the interference of such infections with the immune responses against cancer has been poorly investigated. Through a mathematical model, we show that the frequency, the duration and the action (positive or negative) of immune challenges may significantly impact tumor proliferation. First, we observe that a long immunosuppressive challenge increases accumulation of cancerous cells only if it occurs 14 years after the beginning of immunosenescence. However, short immune challenges result in an even greater accumulation of cancerous cells for the same total duration of immunosuppression. Finally, we show that short challenges of immune activation could lead to a slightly decrease in cancerous cell accumulation compared to a long one. Our results predict that frequent and acute immune challenges could have a different and in some extent higher impact on cancer risk than persistent ones even they have been much less studied in cancer epidemiology. These results are discussed regarding the existing empirical evidences and we suggest potential novel indirect role of infectious diseases on cancer incidence which should be investigated to improve prevention strategies against cancer.

Quantitative and qualitative characterization of expanded CD4+ T cell clones in rheumatoid arthritis patients

Rheumatoid arthritis (RA) is an autoimmune destructive arthritis associated with CD4⁺ T cell-mediated immunity. Although expanded CD4⁺ T cell clones (ECs) has already been confirmed, the detailed characteristics of ECs have not been elucidated in RA. Using combination of a single-cell analysis and next-generation sequencing (NGS) in TCR repertoire analysis, we here revealed the detailed nature of ECs by examining peripheral blood (PB) from 5 RA patients and synovium from 1 RA patient. When we intensively investigated the single-cell transcriptome of the most expanded clones in memory CD4⁺ T cells (memory-mECs) in RA-PB, senescence-related transcripts were up-regulated, indicating circulating ECs were constantly stimulated. Tracking of the transcriptome shift within the same memory-mECs between PB and the synovium revealed the augmentations in senescence-related gene expression and the up-regulation of synovium-homing chemokine receptors in the synovium. Our in-depth characterization of ECs in RA successfully demonstrated the presence of the specific immunological selection pressure, which determines the phenotype of ECs. Moreover, transcriptome tracking added novel aspects to the underlying sequential immune processes. Our approach may provide new insights into the pathophysiology of RA.

Self-recognition drives the preferential accumulation of promiscuous CD4(+) T-cells in aged mice

T-cell recognition of self and foreign peptide antigens presented in major histocompatibility complex molecules (pMHC) is essential for life-long immunity. How the ability of the CD4⁺ T-cell compartment to bind self- and foreign-pMHC changes over the lifespan remains a fundamental aspect of T-cell biology that is largely unexplored. We report that, while old mice (18–22 months) contain fewer CD4⁺ T-cells compared with adults (8–12 weeks), those that remain have a higher intrinsic affinity for self-pMHC, as measured by CD5 expression. Old mice also have more cells that bind individual or multiple distinct foreign-pMHCs, and the fold increase in pMHC-binding populations is directly related to their CD5 levels. These data demonstrate that the CD4⁺ T-cell compartment preferentially accumulates promiscuous constituents with age as a consequence of higher affinity T-cell receptor interactions with self-pMHC.

DOI:http://dx.doi.org/10.7554/eLife.05949.001

The immune system's T cells help the body to recognize and destroy harmful pathogens, such as viruses and bacteria. T cells ‘remember’ immunity-inducing fragments, called antigens, from the pathogens they have encountered. This memory then allows the immune system to quickly fend off infections if those pathogens, or even related pathogens, invade again. Vaccines exploit the ability to form immunological memory by exposing the body to harmless forms of the pathogen, or even just particular antigens from it. This allows the T cells to learn how to identify the pathogen without any risk of illness.

Vaccines have been extremely successful and have helped to virtually eliminate some diseases. However, for reasons that are unclear, the immune systems of older adults become less functional, so vaccines often lose their effectiveness. Paradoxically, as people age T cells become more likely to attack the body's cells, causing autoimmune diseases like arthritis. Understanding what happens to aging T cells to cause these immune changes may help scientists design vaccines that remain effective as people age.

Little is known about what happens to a particular type of T cell—the CD4⁺ T cells—as people age, even though this population plays a critical role in providing other immune cells with detailed instructions on when and how to fight a pathogen. Now, Deshpande et al. show that CD4⁺ T cells undergo a remarkable set of changes in aging mice. Mice that are nearing the end of their natural lifespan have fewer CD4⁺ T cells than younger mice. However, those CD4⁺ T cells that remain are more likely than CD4⁺ T cells from younger mice to be able to recognize multiple antigens. This increase in the proportion of multitasking CD4⁺ T cells corresponds with an increased tendency of these cells to bind to the body's own cells. If similar changes occur in older people, this may help explain some age-related autoimmune diseases. Yet, the relationship between the increase in multitasking CD4⁺ T cells and the decrease in immune function with aging remains to be fully explored.

The challenge for scientists now is to determine how these age-related changes in CD4⁺ T cells affect immune responses to vaccines or pathogens in older individuals. One implication of this work is that CD4⁺ T cell responses may be too robust and out of balance with other arms of the immune system. This could even lead to conditions such as autoimmunity. Alternatively, while there may be more CD4⁺ T cells that can multitask by recognizing multiple antigens, their ability to respond appropriately to infections or vaccinations may be diminished. What is clear from the work of Deshpande et al. is that the rules that have been defined for immunity in adults change with aging. The rules that govern immunity in the elderly must be more clearly defined to realize the goal of designing immunotherapies, such as vaccines, that provide protection throughout the lifespan.

DOI:http://dx.doi.org/10.7554/eLife.05949.002

Anti-inflammatory activity of green versus black tea aqueous extract in a rat model of human rheumatoid arthritis

AIM

Recently, there has been an increasing interest in tea (Camellia sinensis) as a protective agent against inflammatory diseases. Here, we evaluated/compared the anti-inflammatory activity of two different doses (0.5 and 1.0 g/kg body weight) of green tea aqueous extract (GTE, rich in catechins) and black tea aqueous extract (BTE, rich in theaflavins and thearubigins) in rat adjuvant-induced arthritis (AIA).

METHODS

Adjuvant-induced arthritis rat model received orally/daily distilled water as vehicle, indomethacin (1.0 mg/kg body weight; a non-steroidal/anti-inflammatory drug), or tea aqueous extracts (for 28 or 14 consecutive days starting from day 0 or 14 of arthritis induction, respectively).

RESULTS

The present study showed that only the high dose of GTE (from day 0) significantly alleviated (P < 0.05-0.001) all complications shown in arthritic rats, including synovial joint inflammation, elevation in erythrocyte sedimentation rate, blood leukocytosis (due to lymphocytosis and neutrocytosis), and changes in weight/cellularity of lymphoid organs. The anti-arthritic activity of the high dose of GTE (from day 0) was comparable (P > 0.05) with that of indomethacin (12.9-53.8 vs. 9.5-48.4%, respectively) and mediated by significantly decreasing and down-regulating (P < 0.001) the systemic production of pro-inflammatory cytokines and the expression of chemokine receptor-5 in synovial tissues, respectively. Moreover, the anti-arthritic activity of tea aqueous extracts was in the following order: high dose of GTE > low dose of GTE ≥ high dose of BTE > low dose of BTE.

CONCLUSION

The present study proved the anti-inflammatory activity of GTE over BTE and equal to that of indomethacin in AIA rat model.

ACTH controls thymocyte homeostasis independent of glucocorticoids

It has been known for decades that lowering the circulating glucocorticoid (GC) concentration as in Addison's disease or after removing the adrenals results in thymus enlargement, largely due to thymocyte expansion. This has been attributed to the loss of the proapoptotic effects on thymocytes by adrenal GCs. Here, we test this concept and report that ACTH directly controls thymic growth post-adrenalectomy (ADX) independent of the proapoptotic effect of GCs. This was supported by the finding that ADX caused thymus enlargement and a 1.7-fold (P < 0.001) increase in thymocyte number in GR(LckCre) mice resistant to GC-induced thymocyte apoptosis, similar to the increase seen in wild-type mice (2.2-fold; P < 0.01). We show by immunostaining that melanocortin receptor subtype 2, which selectively binds ACTH, is partly expressed on the thymic epithelium. Furthermore, ACTH in comparison to vehicle induced a 2.0-fold (P < 0.01) increase in fetal thymic organ culture thymocyte numbers in vitro and enhanced 2.2-fold (P < 0.05) the expression of delta-like ligand 4, a factor that supports T-cell development. Additionally, adrenalectomized GR(LckCre) mice treated with ACTH under conditions that repressed endogenous ACTH secretion showed increased thymocyte cellularity (1.9-fold; P < 0.01) and splenic naive T-cell numbers (2.5-fold; P < 0.001) compared to when treated with PBS. Altogether, our results show that ACTH directly controls thymocyte homeostasis independent of GCs. These results revise the old paradigm behind compensatory thymus growth following ADX, now demonstrating that ACTH has a central role in regulating thymocyte expansion when systemic GC concentration is low.

Study of the association between CD28/CTLA-4 expression and disease activity in juvenile idiopathic arthritis

The aim of the present study was to investigate the immune function of children with juvenile idiopathic arthritis (JIA). Flow cytometry and three-color direct immunofluorescence were used to examine cluster of differentiation (CD)3⁺ T-lymphocyte subsets and CD28/cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) expression in whole blood (using the no-wash method) from 36 children with JIA and 39 healthy children. During the active phase of JIA, CD28 expression on CD4⁺ T cells in children with JIA was significantly reduced; thus, CD4⁺CD28^- T-cell frequency increased, suggesting that CD4⁺ T-cell and CD4⁺CD28^- T-cell apoptosis was inhibited in patients with JIA. The continued survival of these immune-active T lymphocytes may promote the occurrence and development of JIA. CTLA-4 expression levels on CD4⁺ and CD8⁺ T cells in children with JIA during the active phase were significantly higher than those in normal controls. As the majority of CD4⁺ T cells in patients with JIA are CD28^-, they cannot be inactivated by the interaction between CTLA-4 and B7, leading to continuously high levels of CTLA-4 expression on the surface of CD4⁺ T cells without functional effect. Hence, T lymphocytes are continuously kept in a highly activated state that is difficult to stop. During the resting phase, the CD4⁺ and CD8⁺ T-cell counts in children with JIA were similar to normal, and CD28 expression was also normal. This suggests that the frequency of CD4⁺CD28^- T cells can be used as an indicator of the active phase of JIA. CTLA-4 expression on the surface of T cells in children with JIA during the resting phase was also similar to that in normal controls, suggesting that abnormal lymphocyte activation plays an important role in the active phase of JIA.

T-cell metabolism in autoimmune disease

Cancer cells have long been known to fuel their pathogenic growth habits by sustaining a high glycolytic flux, first described almost 90 years ago as the so-called Warburg effect. Immune cells utilize a similar strategy to generate the energy carriers and metabolic intermediates they need to produce biomass and inflammatory mediators. Resting lymphocytes generate energy through oxidative phosphorylation and breakdown of fatty acids, and upon activation rapidly switch to aerobic glycolysis and low tricarboxylic acid flux. T cells in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) have a disease-specific metabolic signature that may explain, at least in part, why they are dysfunctional. RA T cells are characterized by low adenosine triphosphate and lactate levels and increased availability of the cellular reductant NADPH. This anti-Warburg effect results from insufficient activity of the glycolytic enzyme phosphofructokinase and differentiates the metabolic status in RA T cells from those in cancer cells. Excess production of reactive oxygen species and a defect in lipid metabolism characterizes metabolic conditions in SLE T cells. Owing to increased production of the glycosphingolipids lactosylceramide, globotriaosylceramide and monosialotetrahexosylganglioside, SLE T cells change membrane raft formation and fail to phosphorylate pERK, yet hyperproliferate. Borrowing from cancer metabolomics, the metabolic modifications occurring in autoimmune disease are probably heterogeneous and context dependent. Variations of glucose, amino acid and lipid metabolism in different disease states may provide opportunities to develop biomarkers and exploit metabolic pathways as therapeutic targets.

Premature immunosenescence is associated with memory dysfunction in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) has been associated with premature immunosenescence and an increased prevalence of age-related morbidities including poor cognitive function.

OBJECTIVE

We explored the relationships among lymphocyte subsets and memory in RA.

METHODS

Thirty patients with RA and 19 age-matched healthy controls took part in this study. Cognitive function stress and depression scores were evaluated by structured clinical questionnaires. Lymphocytes were isolated and immunophenotyped by flow cytometry to investigate the following subsets: B cells, activated and naïve/memory T cells, regulatory FoxP3+ T (Treg) cells, Th17+ cells, NK cells and senescence-associated CD28- T cells.

RESULTS

RA patients were more depressed than controls, but stress levels were similar in the 2 groups. Patients had impaired memory performance compared to controls, demonstrated by lower Mini-Mental State Examination scores and logical and working memories (all p < 0.0001). These group effects remained significant after correcting for depression and age. Patients had expansion of regulatory T cells, naïve CD4+ T cells and CD8+CD28- cells but reduced percentages of B cells and memory CD8+CD45RO+ T cells compared to controls. CD8+CD28- and CD8+CD45RO+ T cells were found to be negatively associated with memory.

CONCLUSION

RA patients had reduced memory performance compared to healthy controls. Expansion of activated and senescence-associated T cells was correlated with poor memory performance.

TNFα polymorphism as marker of immunosenescence for rheumatoid arthritis patients

BACKGROUND

Expansion of CD4(+)CD28(null), a common feature of immunosenescence, which has been reported in rheumatoid arthritis (RA) patients, may also be associated with a CD4(+) imbalance. Although the increase of CD4(+)CD28(null) cells has been related to TNFα exposure, nothing is known about the possible role of genetic variants of this cytokine.

METHODS

Participants were genotyped for TNFA rs1800629 (-308 G>A) and frequency of the CD4(+)CD28(null), regulatory T cells and Th1 cells subsets were quantified in peripheral blood samples by flow cytometry in 129 RA patients and 33 healthy controls.

RESULTS

The expansion of CD4(+)CD28(null) cells in RA patients was associated with TNFA genotype, even at diagnosis, and linked to markers of aggressive disease in patient carriers of the minor allele. Analysis of regulatory T cells and IFNγ-CD4(+) expression suggested that defective suppression and/or Th1-shift could underlie the expansion of this population in these patients. Finally, although treatment with TNFα-blockers reduced CD4(+)CD28(null) cells in most patients, only those carriers of the common GG genotype reached values within the range of HC and showed a disease activity improvement correlated to this decrease.

CONCLUSIONS

Our results provide evidence for a genetic basis of the premature immunosenescence of RA patients and highlight its potential role in clinical outcome after TNFα blockade.

Determinants of mortality among postmenopausal women in the women's health initiative who report rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) patients have an increased risk of cardiovascular disease (CVD) and mortality. We measured anti-cyclic citrullinated peptide (anti-CCP) antibody levels and determined use of disease-modifying antirheumatic drugs (DMARDs) among women in the Women's Health Initiative (WHI). Using these data, we undertook this study to assess total mortality over 10 years of followup among white, black, or Hispanic women with self-reported RA in the WHI.

METHODS

Using stored baseline serum, we measured anti-CCP, rheumatoid factor (RF), and antinuclear antibodies (ANAs) in 9,988 women who reported having RA. Based on a previous chart review study, probable RA was defined as either self-reported RA and anti-CCP positivity, or anti-CCP negativity and DMARD use. Cox proportional hazards regression was used to model the relationship of self-reported RA, DMARD exposure, and anti-CCP positivity to total mortality, using followup data through April 2009.

RESULTS

At baseline, the mean age was 62.8 years; 24.5% of subjects were black and 10% were Hispanic. Prevalence of anti-CCP positivity was 8.1% (n = 812), and 217 women were anti-CCP negative but had reported use of DMARDs; therefore, 1,029 women (of 9,988) were classified as having probable RA, and 8,958 were classified as unlikely to have RA (with data on DMARD use missing for 1 subject). Age-adjusted mortality rates were ∼2-fold higher for anti-CCP-positive women, with 20.2 deaths per 1,000 person-years, as compared to 11.4 deaths per 1,000 person-years among anti-CCP-negative women with self-reported RA who never used DMARDs. Among women who did not report any arthritis at baseline, we found 8.3 deaths per 1,000 person-years. The increased risk among anti-CCP-positive women with RA was not explained by age, RF positivity, ANA positivity, or DMARD use.

CONCLUSION

Anti-CCP-positive RA was associated with substantial excess mortality among postmenopausal women in the WHI. This result was not explained by the risk factors we measured.

An age-related numerical and functional deficit in CD19(+) CD24(hi) CD38(hi) B cells is associated with an increase in systemic autoimmunity

Autoimmunity increases with aging indicative of reduced immune tolerance, but the mechanisms involved are poorly defined. In recent years, subsets of B cells with immunoregulatory properties have been identified in murine models of autoimmune disorders, and these cells downregulate immune responses via secretion of IL10. In humans, immature transitional B cells with a CD19(+) CD24(hi) CD38(hi) phenotype have been reported to regulate immune responses via IL10 production. We found the frequency and numbers of CD19(+) CD24(hi) CD38(hi) cells were reduced in the PBMC pool with age. IL10 expression and secretion following activation via either CD40, or Toll-like receptors was also impaired in CD19(+) CD24(hi) CD38(hi) B cells from healthy older donors. When investigating the mechanisms involved, we found that CD19(+) CD24(hi) CD38(hi) B-cell function was compromised by age-related effects on both T cells and B cells: specifically, CD40 ligand expression was lower in CD4 T cells from older donors following CD3 stimulation, and signalling through CD40 was impaired in CD19(+) CD24(hi) CD38(hi) B cells from elders as evidenced by reduced phosphorylation (Y705) and activation of STAT3. However, there was no age-associated change in expression of costimulatory molecules CD80 and CD86 on CD19(+) CD24(hi) CD38(hi) cells, suggesting IL10-dependent immune suppression is impaired, but contact-dependent suppressive capacity is intact with age. Finally, we found a negative correlation between CD19(+) CD24(hi) CD38(hi) B-cell IL10 production and autoantibody (Rheumatoid factor) levels in older adults. We therefore propose that an age-related decline in CD19(+) CD24(hi) CD38(hi) B cell number and function may contribute towards the increased autoimmunity and reduced immune tolerance seen with aging.

Comorbidities are associated with poorer outcomes in community patients with rheumatoid arthritis

OBJECTIVE

To evaluate the impact of comorbidities on achieving remission by examining changes in the clinical disease activity index (CDAI) in RA patients in the community-based Consortium of Rheumatology Researchers of North America (CORRONA) registry.

METHODS

A subcohort of 1548 RA subjects with varying disease duration met the following inclusion criteria: started a DMARD/biologic agent, continued therapy ≥ 3 months, CDAI ≥ 2.8 at study entry and followed longitudinally from baseline to follow-up (mean time 7.46 months). Patients reported comorbidities according to a standardized list of 33 conditions. Entry characteristics were compared across age categories using one-way analysis of variance. Linear and logistic regression models were constructed to assess characteristics [e.g. age, disease duration, number of previous DMARDs/biologics, baseline modified health assessment questionnaire (MHAQ), baseline CDAI and number of comorbidities] associated with primary outcomes: change in CDAI (baseline to follow-up) and CDAI remission (yes/no).

RESULTS

Although disease activity measures at entry were similar across age categories, older patients had more comorbidities, less improvement in CDAI/MHAQ and were less likely to attain remission at follow-up. However, after adjusting covariates an increasing number of patient-reported comorbidities and higher baseline CDAI (but not age) were consistently and independently associated with a lower likelihood of clinical improvement or remission (P < 0.001).

CONCLUSION

In this observational cohort of community RA patients an increasing number of patients reported comorbidities, independently correlated with less CDAI improvement over time. These results reaffirm that comorbidities may be an important factor in consideration of treat-to-target recommendations and aid in understanding achievable RA therapeutic goals.

Increased replication of CD4+ naive T cells and changes in T cell homeostasis in a case of acute exacerbation of juvenile idiopathic arthritis: a case comparison study

Introduction

Juvenile idiopathic arthritis is a heterogeneous T cell-mediated autoimmune disease with symptoms of premature aging of the immune system (immunosenescence). The present work is an investigation of immunosenescence parameters, such as quantity of naive and CD28^- T cells, T cell receptor excision circles, relative telomere length and alterations of peripheral T cell replication, and was performed via comparison of a case of acute exacerbation of juvenile idiopathic arthritis against six patients with juvenile idiopathic arthritis with disease remission and six age-matched healthy donors over a follow-up course of 12 months.

Case presentation

Phenotypical T cell characterization and intracellular interferon γ, tumor necrosis factor α, and interleukin 2 production were studied in peripheral blood mononuclear cells from seven patients with juvenile idiopathic arthritis and six healthy control donors, with findings determined by flow cytometry. T cell receptor excision circles and relative telomere length quantification were performed on deoxyribonucleic acid isolated from naive (CD4⁺CD28⁺CD45RA⁺) T cells and investigated via reverse transcription polymerase chain reaction. Ki67 expression was studied by immunohistochemistry on naive T cells. The non-parametric Mann-Whitney U test and Wilcoxon test for two independent groups of variables were used to compare healthy donors with patients with juvenile idiopathic arthritis. During follow-up, patients with juvenile idiopathic arthritis showed lower total counts of naive and CD28-expressing T cells compared to healthy donors. Acute exacerbation led to low naive and CD28⁺ T cell populations and elevated proportions of Ki67-expressing CD4⁺ naive T cells. In conditions of exacerbation, T cell receptor excision circle numbers were in the lower range in patients with juvenile idiopathic arthritis and increased after follow-up. Healthy donors showed significantly higher relative telomere lengths compared to patients with juvenile idiopathic arthritis.

Conclusions

This investigation illustrates that the changes in T cell homeostasis in patients with juvenile idiopathic arthritis may be the result of several mechanisms, such as diminished thymus function and peripheral exertions to maintain the peripheral T cell pool. The results also demonstrate that hallmarks of immunosenescence such as decreased naive T cell levels and lower T cell receptor excision circle numbers can only be interpreted together with replication markers such as relative telomere length or Ki67 expression.

Effects of shark cartilage polysaccharides on the secretion of IL-6 and IL-12 in rheumatoid arthritis

CONTEXT

Rheumatoid arthritis (RA) is a chronic inflammatory disease caused by inflammation of the synovial membrane, leading to articular cartilage destruction. Shark cartilage polysaccharide (SCP) is a biodegradable, biocompatible, nontoxic, non-immunogenic and non-inflammatory polysaccharide that may be used in treating RA.

OBJECTIVE

The anti-RA activities of SCP given orally to rats are investigated here for the first time.

MATERIALS AND METHODS

SCP treatment group were administered with SCP-1, SCP-2 in the dosage of 9 mg/day for 24 days. The effect of SCP-1 and SCP-2 on the body weight, paw swelling, morphological changes of ankle and IL-6, IL-12 secretion in RA rats are examined.

RESULTS

On day 24, there were no obvious differences in BMI between positive, SCP-1 and SCP-2 group. The swelling degree of SCP-1 and SCP-2 group was less serious than model group. X-ray revealed that SCP-1, SCP-2 group owned normal joint alignment and more smooth and tidy articular surface. The SCP-1 and SCP-2 have inhibitory effect on IL-6 (430.3 ± 25.6 pg/mL, 439.1 ± 35.9 pg/mL) and IL-12 (63.9 ± 20.1 pg/mL, 64.9 ± 14.1 pg/mL) secretion, which showed significant differences with model group (612 ± 72.3 pg/mL, 230.1 ± 29.2 pg/mL), but still higher than normal group (361.8 ± 47.1 pg/mL, 34.2 ± 15.1 pg/mL) and lower than positive group (418.1 ± 42.5 pg/mL, 90.2 ± 17.8 pg/mL). Especially, when the concentration of SCP was 125 μg/mL, the contents of IL-6 (431.1 ± 43.3 pg/mL, 401.7 ± 55.7 pg/mL) and IL-12 (63.2 ± 12.3 pg/mL, 52.3 ± 8.7 pg/mL) were lowest.

DISCUSSION AND CONCLUSION

These findings demonstrate that SCP have excellent anti-RA activities and thus have great potential as a drug for treating RA diseases.

K-RAS GTPase- and B-RAF kinase-mediated T-cell tolerance defects in rheumatoid arthritis

Autoantibodies to common autoantigens and neoantigens, such as IgG Fc and citrullinated peptides, are immunological hallmarks of rheumatoid arthritis (RA). We examined whether a failure in maintaining tolerance is mediated by defects in T-cell receptor activation threshold settings. RA T cells responded to stimulation with significantly higher ERK phosphorylation (P < 0.001). Gene expression arrays of ERK pathway members suggested a higher expression of KRAS and BRAF, which was confirmed by quantitative PCR (P = 0.003), Western blot, and flow cytometry (P < 0.01). Partial silencing of KRAS and BRAF lowered activation-induced phosphorylated ERK levels (P < 0.01). In individual cells, levels of these signaling molecules correlated with ERK phosphorylation, attesting that their concentrations are functionally important. In confocal studies, B-RAF/K-RAS clustering was increased in RA T cells 2 min after T-cell receptor stimulation (P < 0.001). Overexpression of B-RAF and K-RAS in normal CD4 T cells amplified polyclonal T-cell proliferation and facilitated responses to citrullinated peptides. We propose that increased expression of B-RAF and K-RAS lowers T-cell activation thresholds in RA T cells, enabling responses to autoantigens.

NKG2D expression in CD4+ T lymphocytes as a marker of senescence in the aged immune system

Human aging is characterized by changes in the immune system which have a profound impact on the T-cell compartment. These changes are more frequently found in CD8+ T cells, and there are not well-defined markers of differentiation in the CD4+ subset. Typical features of cell immunosenescence are characteristics of pathologies in which the aberrant expression of NKG2D in CD4+ T cells has been described. To evaluate a possible age-related expression of NKG2D in CD4+ T cells, we compared their percentage in peripheral blood from 100 elderly and 50 young adults. The median percentage of CD4+ NKG2D+ in elders was 5.3% (interquartile range (IR): 8.74%) versus 1.4% (IR: 1.7%) in young subjects (p < 0.3 × 10(-10)). CD28 expression distinguished two subsets of CD4+ NKG2D+ cells with distinct functional properties and differentiation status. CD28+ cells showed an immature phenotype associated with high frequencies of CD45RA and CD31. However, most of the NKG2D+ cells belonged to the CD28(null) compartment and shared their phenotypical properties. NKG2D+ cells represented a more advanced stage of maturation and exhibited greater response to CMV (5.3 ± 3.1% versus 3.4 ± 2%, p = 0.037), higher production of IFN-γ (40.56 ± 13.7% versus 24 ± 8.8%, p = 0.015), lower activation threshold and reduced TREC content. Moreover, the frequency of the CD4+ NKG2D+ subset was clearly related to the status of the T cells. Higher frequencies of the NKG2D+ subset were accompanied with a gradual decrease of NAIVE and central memory cells, but also with a higher level of more differentiated subsets of CD4+ T cells. In conclusion, CD4+ NKG2D+ represent a subset of highly differentiated T cells which characterizes the senescence of the immune system.

Impact of aging on dendritic cell functions in humans

Aging is a paradox of reduced immunity and chronic inflammation. Dendritic cells are central orchestrators of the immune response with a key role in the generation of immunity and maintenance of tolerance. The functions of DCs are compromised with age. There is no major effect on the numbers and phenotype of DC subsets in aged subjects; nevertheless, their capacity to phagocytose antigens and migrate is impaired with age. There is aberrant cytokine secretion by various DC subsets with CDCs secreting increased basal level of pro-inflammatory cytokines but the response on stimulation to foreign antigens is decreased. In contrast, the response to self-antigens is increased suggesting erosion of peripheral self tolerance. PDC subset also secretes reduced IFN-α in response to viruses. The capacity of DCs to prime T cell responses is also affected. Aging thus has a profound affect on DC functions. Present review summarizes the effect of advancing age on DC functions in humans in the context of both immunity and tolerance.