When Should I Get My Next COVID-19 Vaccine? Data From the Surveillance of Responses to COVID-19 Vaccines in Systemic Immune-Mediated Inflammatory Diseases (SUCCEED) Study.

OBJECTIVE: To determine how serologic responses to coronavirus disease 2019 (COVID-19) vaccination and infection in immune-mediated inflammatory disease (IMID) are affected by time since last vaccination and other factors. METHODS: Post-COVID-19 vaccination, data, and dried blood spots or sera were collected from adults with rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, ankylosing spondylitis and spondylarthritis, and psoriasis and psoriatic arthritis. The first sample was collected at enrollment, then at 2 to 4 weeks and 3, 6, and 12 months after the latest vaccine dose. Multivariate generalized estimating equation regressions (including medications, demographics, and vaccination history) evaluated serologic response, based on log-transformed anti-receptor-binding domain (RBD) IgG titers; we also measured antinucleocapsid (anti-N) IgG. RESULTS: Positive associations for log-transformed anti-RBD titers were seen with female sex, number of doses, and self-reported COVID-19 infections in 2021 to 2023. Negative associations were seen with prednisone, anti-tumor necrosis factor agents, and rituximab. Over the 2021-2023 period, most (94%) of anti-N positivity was associated with a self-reported infection in the 3 months prior to testing. From March 2021 to February 2022, anti-N positivity was present in 5% to 15% of samples and was highest in the post-Omicron era, with antinucleocapsid positivity trending to 30% to 35% or higher as of March 2023. Anti-N positivity in IMID remained lower than Canada's general population seroprevalence (> 50% in 2022 and > 75% in 2023). Time since last vaccination was negatively associated with log-transformed anti-RBD titers, particularly after 210 days. CONCLUSION: Ours is the first pan-Canadian IMID assessment of how vaccine history and other factors affect serologic COVID-19 vaccine responses. These findings may help individuals personalize vaccination decisions, including consideration of additional vaccination when > 6 months has elapsed since last COVID-19 vaccination/infection.

Immunomodulatory drugs have divergent effects on humoral and cellular immune responses to SARS-CoV-2 vaccination in people living with rheumatoid arthritis.

Understanding the efficacy of SARS-CoV-2 vaccination in people on immunosuppressive drugs, including those with rheumatoid arthritis (RA), is critical for their protection. Vaccine induced protection requires antibodies, CD4+ T cells, and CD8+ T cells, but it is unclear if these are equally affected by immunomodulatory drugs. Here, we determined how humoral and cellular SARS-CoV-2 vaccination responses differed between people with RA and controls, and which drug classes impacted these responses. Blood was collected from participants with RA on immunomodulatory drugs and controls after their second, third, and fourth SARS-CoV-2 vaccinations. Receptor binding domain (RBD)-specific antibodies were quantified by ELISA. Spike-specific memory T cells were quantitated using flow cytometry. Linear mixed models assessed the impact of age, sex, and immunomodulatory drug classes on SARS-CoV-2 vaccination responses. Compared to non-RA controls (n = 35), participants with RA on immunomodulatory drugs (n = 62) had lower anti-RBD IgG and spike-specific CD4+ T cell levels, but no deficits in spike-specific CD8+ T cells, following SARS-CoV-2 vaccination. Use of costimulation inhibitors was associated with lower humoral responses. JAK inhibitors were associated with fewer spike-specific CD4+ T cells. Participants with RA on immunomodulatory drugs mounted weaker responses to SARS-CoV-2 vaccination, with different drug classes impacting the cellular and humoral compartments.

Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome.

Symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are common in rheumatic diseases, but no studies report the frequency of these in early systemic sclerosis. There are no known biomarkers that can distinguish between patients with ME/CFS, although mitochondrial abnormalities are often demonstrated. We sought to assess the prevalence of ME/CFS in limited cutaneous SSc (lcSSc) patients early in their disease (<5 years from the onset of non-Raynaud's symptoms) and to determine if alterations in mitochondrial electron transport chain (ETC) transcripts and mitochondrial DNA (mtDNA) integrity could be used to distinguish between fatigued and non-fatigued patients. All SSc patients met ACR/EULAR classification criteria. ME/CFS-related symptoms were assessed through validated questionnaires, and the expression of ETC transcripts and mtDNA integrity were quantified via qPCR. SSc patients with ME/CFS could be distinguished from non-fatigued patients through ETC gene analysis; specifically, reduced expression of ND4 and CyB and increased expression of Cox7C. ND4 and CyB expression correlated with indicators of disease severity. Further prospective and functional studies are needed to determine if this altered signature can be further utilized to better identify ME/CFS in SSc patients, and whether ME/CFS in early SSc disease could predict more severe disease outcomes.

Stricter treat-to-target in RA does not result in less radiographic progression: a longitudinal analysis in RA BIODAM.

OBJECTIVES: To investigate whether meticulously following a treat-to-target (T2T)-strategy in daily clinical practice will lead to less radiographic progression in patients with active RA who start (new) DMARD-therapy. METHODS: Patients with RA from 10 countries starting/changing conventional synthetic or biologic DMARDs because of active RA, and in whom treatment intensification according to the T2T principle was pursued, were assessed for disease activity every 3 months for 2 years (RA-BIODAM cohort). The primary outcome was the change in Sharp-van der Heijde (SvdH) score, assessed every 6 months. Per 3-month interval DAS44-T2T could be followed zero, one or two times (in a total of two visits). The relation between T2T intensity and change in SvdH-score was modelled by generalized estimating equations. RESULTS: In total, 511 patients were included [mean (s.d.) age: 56 (13) years; 76% female]. Mean 2-year SvdH progression was 2.2 (4.1) units (median: 1 unit). A stricter application of T2T in a 3-month interval did not reduce progression in the same 6-month interval [parameter estimates (for yes vs no): +0.15 units (95% CI: -0.04, 0.33) for 2 vs 0 visits; and +0.08 units (-0.06; 0.22) for 1 vs 0 visits] nor did it reduce progression in the subsequent 6-month interval. CONCLUSIONS: In this daily practice cohort, following T2T principles more meticulously did not result in less radiographic progression than a somewhat more lenient attitude towards T2T. One possible interpretation of these results is that the intention to apply T2T already suffices and that a more stringent approach does not further improve outcome.

Prolonged COVID-19 symptom duration in people with systemic autoimmune rheumatic diseases: results from the COVID-19 Global Rheumatology Alliance Vaccine Survey.

OBJECTIVE: We investigated prolonged COVID-19 symptom duration, defined as lasting 28 days or longer, among people with systemic autoimmune rheumatic diseases (SARDs). METHODS: We analysed data from the COVID-19 Global Rheumatology Alliance Vaccine Survey (2 April 2021-15 October 2021) to identify people with SARDs reporting test-confirmed COVID-19. Participants reported COVID-19 severity and symptom duration, sociodemographics and clinical characteristics. We reported the proportion experiencing prolonged symptom duration and investigated associations with baseline characteristics using logistic regression. RESULTS: We identified 441 respondents with SARDs and COVID-19 (mean age 48.2 years, 83.7% female, 39.5% rheumatoid arthritis). The median COVID-19 symptom duration was 15 days (IQR 7, 25). Overall, 107 (24.2%) respondents had prolonged symptom duration (≥28 days); 42/429 (9.8%) reported symptoms lasting ≥90 days. Factors associated with higher odds of prolonged symptom duration included: hospitalisation for COVID-19 vs not hospitalised and mild acute symptoms (age-adjusted OR (aOR) 6.49, 95% CI 3.03 to 14.1), comorbidity count (aOR 1.11 per comorbidity, 95% CI 1.02 to 1.21) and osteoarthritis (aOR 2.11, 95% CI 1.01 to 4.27). COVID-19 onset in 2021 vs June 2020 or earlier was associated with lower odds of prolonged symptom duration (aOR 0.42, 95% CI 0.21 to 0.81). CONCLUSION: Most people with SARDs had complete symptom resolution by day 15 after COVID-19 onset. However, about 1 in 4 experienced COVID-19 symptom duration 28 days or longer; 1 in 10 experienced symptoms 90 days or longer. Future studies are needed to investigate the possible relationships between immunomodulating medications, SARD type/flare, vaccine doses and novel viral variants with prolonged COVID-19 symptoms and other postacute sequelae of COVID-19 among people with SARDs.

Baseline factors associated with self-reported disease flares following COVID-19 vaccination among adults with systemic rheumatic disease: results from the COVID-19 global rheumatology alliance vaccine survey.

OBJECTIVE: To examine the frequency of, and risk factors for, disease flare following COVID-19 vaccination in patients with systemic rheumatic disease (SRD). METHODS: An international study was conducted from 2 April to 16 August 2021, using an online survey of 5619 adults with SRD for adverse events following COVID-19 vaccination, including flares of disease requiring a change in treatment. We examined risk factors identified a priori based on published associations with SRD activity and SARS-CoV-2 severity, including demographics, SRD type, comorbidities, vaccine type, cessation of immunosuppressive medications around vaccination and history of reactions to non-COVID-19 vaccines, using multivariable logistic regression. RESULTS: Flares requiring a change in treatment following COVID-19 vaccination were reported by 4.9% of patients. Compared with rheumatoid arthritis, certain SRD, including systemic lupus erythematosus (OR 1.51, 95% CI 1.03, 2.20), psoriatic arthritis (OR 1.95, 95% CI 1.20, 3.18) and polymyalgia rheumatica (OR 1.94, 95% CI 1.08, 2.48) were associated with higher odds of flare, while idiopathic inflammatory myopathies were associated with lower odds for flare (OR 0.54, 95% CI 0.31-0.96). The Oxford-AstraZeneca vaccine was associated with higher odds of flare relative to the Pfizer-BioNTech vaccine (OR 1.44, 95% CI 1.07, 1.95), as were a prior reaction to a non-COVID-19 vaccine (OR 2.50, 95% CI 1.76, 3.54) and female sex (OR 2.71, 95% CI 1.55, 4.72). CONCLUSION: SRD flares requiring changes in treatment following COVID-19 vaccination were uncommon in this large international study. Several potential risk factors, as well as differences by disease type, warrant further examination in prospective cohorts.

Early impacts of the COVID-19 pandemic on children with pediatric rheumatic diseases.

OBJECTIVES: The experiences of children with pediatric rheumatic diseases (PRD) during the initial phase of the COVID-19 pandemic have not been well-documented. We sought to determine the effects of the COVID-19 pandemic on protective behaviors, healthcare access, medication management, and education among an international cross-sectional parental survey of children with PRDs. METHODS: The COVID-19 Global Rheumatology Alliance Patient Experience Survey was distributed online, and parents of children with parental-reported PRD, with or without COVID-19 infection, were eligible to enroll. Respondents described their child's demographics, adoptions of protective behaviors, healthcare access, changes to immunosuppression, and disruptions in schooling. RESULTS: A total of 427 children were included in the analyses. The most common rheumatic disease was juvenile idiopathic arthritis (40.7%), and most children were taking conventional synthetic diseasemodifying antirheumatic drugs (DMARDs) (54.6%) and/or biologic DMARDs (51.8%). A diagnosis of COVID-19 was reported in five children (1.2%), none of whom required hospitalization. Seventeen children (4.0%) had stopped or delayed their drugs due to concern for immunosuppression, most commonly glucocorticoids. Almost all families adopted behaviors to protect their children from COVID-19, including quarantining, reported by 96.0% of participants. In addition, 98.3% of full-time students experienced disruptions in their education, including cancelations of classes and transitions to virtual classrooms. CONCLUSION: Despite the low numbers of children with PRDs who developed COVID-19 in this cohort, most experienced significant disruptions in their daily lives, including quarantining and interruptions in their education. The drastic changes to these children's environments on their future mental and physical health and development remain unknown.

Immediate effect of the COVID-19 pandemic on patient health, health-care use, and behaviours: results from an international survey of people with rheumatic diseases.

BACKGROUND: The impact and consequences of the COVID-19 pandemic on people with rheumatic disease are unclear. We developed the COVID-19 Global Rheumatology Alliance Patient Experience Survey to assess the effects of the COVID-19 pandemic on people with rheumatic disease worldwide. METHODS: Survey questions were developed by key stakeholder groups and disseminated worldwide through social media, websites, and patient support organisations. Questions included demographics, rheumatic disease diagnosis, COVID-19 diagnosis, adoption of protective behaviours to mitigate COVID-19 exposure, medication access and changes, health-care access and communication with rheumatologists, and changes in employment or schooling. Adults age 18 years and older with inflammatory or autoimmune rheumatic diseases were eligible for inclusion. We included participants with and without a COVID-19 diagnosis. We excluded participants reporting only non-inflammatory rheumatic diseases such as fibromyalgia or osteoarthritis. FINDINGS: 12 117 responses to the survey were received between April 3 and May 8, 2020, and of these, 10 407 respondents had included appropriate age data. We included complete responses from 9300 adults with rheumatic disease (mean age 46·1 years; 8375 [90·1%] women, 893 [9·6%] men, and 32 [0·3%] participants who identified as non-binary). 6273 (67·5%) of respondents identified as White, 1565 (16·8%) as Latin American, 198 (2·1%) as Black, 190 (2·0%) as Asian, and 42 (0·5%) as Native American or Aboriginal or First Nation. The most common rheumatic disease diagnoses included rheumatoid arthritis (3636 [39·1%] of 9300), systemic lupus erythematosus (2882 [31·0%]), and Sjögren's syndrome (1290 [13·9%]). Most respondents (6921 [82·0%] of 8441) continued their antirheumatic medications as prescribed. Almost all (9266 [99·7%] of 9297) respondents adopted protective behaviours to limit SARS-CoV-2 exposure. A change in employment status occurred in 2524 (27·1%) of 9300) of respondents, with a 13·6% decrease in the number in full-time employment (from 4066 to 3514). INTERPRETATION: People with rheumatic disease maintained therapy and followed public health advice to mitigate the risks of COVID-19. Substantial employment status changes occurred, with potential implications for health-care access, medication affordability, mental health, and rheumatic disease activity. FUNDING: American College of Rheumatology.

Fecal microbiome differs between patients with systemic sclerosis with and without small intestinal bacterial overgrowth.

Introduction: Gastrointestinal manifestations of systemic sclerosis affect up to 90% of patients, with symptoms including diarrhea and constipation. Small intestinal bacterial overgrowth is a condition associated with increased numbers of pathogenic bacteria in the small bowel. While currently unknown, it has been suggested that dysregulation of the fecal microbiota may play a role in the development of systemic sclerosis and small intestinal bacterial overgrowth. Objectives: Our study aimed to describe the fecal microbiota of patients with systemic sclerosis and compare it between those with and without a diagnosis of small intestinal bacterial overgrowth. We also compared the fecal microbiota of systemic sclerosis patients with that of healthy controls to understand the association between particular bacterial taxa and clinical gastrointestinal manifestations of systemic sclerosis. Methods: A total of 29 patients with systemic sclerosis underwent breath testing to assess for small intestinal bacterial overgrowth, provided stool samples to determine taxonomic assignments, and completed the University of California Los Angeles Scleroderma Clinical Trial Consortium Gastrointestinal Tract 2.0, which details symptoms and quality-of-life factors. Stool samples were compared between systemic sclerosis patients with and without small intestinal bacterial overgrowth, and between patients with systemic sclerosis and a healthy control cohort (n = 20), aged 18-80 years. Results: Fecal microbiome analyses demonstrated differences between systemic sclerosis patients with and without small intestinal bacterial overgrowth and differences in the diversity of species between healthy controls and patients with systemic sclerosis. Trends were also observed in anticentromere antibody systemic sclerosis patients, including higher Alistipies indistincus spp. levels associated with increased methane levels of breath gas testing and higher Slakia spp. levels associated with increased rates of fecal soiling. Conclusions: Our results suggest that changes to the fecal microbiome occur in patients with small intestinal bacterial overgrowth and systemic sclerosis when compared to healthy controls. As a cross-sectional study, the potential pathophysiologic role of an altered microbiome in the development of systemic sclerosis was not considered and hence needs to be further investigated.

Ultrasonography supplements clinical exam to improve early rheumatoid arthritis disease activity monitoring in metatarsophalangeal joints.

INTRODUCTION: Compared with clinical examination (CE), ultrasonography (US) provides additional and more accurate assessment of inflammation and visualization of structural damage. To better understand the effectiveness of US in metatarsophalangeal joints (MTPJs), we compared disease activity in MTPJs 2-5 assessed by CE and US, with magnetic resonance imaging (MRI) as reference standard. METHOD: Treatment-naïve adult patients with early RA (ACR criteria, disease duration < 2 years) were consecutively recruited. MTPJs 2-5 were assessed for swelling and tenderness, and imaged by US (Esaote MyLab70). The most symptomatic foot was imaged by peripheral MRI (1.0 Tesla). US was semiquantitatively graded for synovial thickening (ST) and power Doppler (PD) (0-3), and erosions (yes/no). MRI was semiquantitatively graded for bone marrow edema (BME), synovitis, and erosions (OMERACT). Kappa agreement, sensitivity, specificity, and predictive values were analyzed using cut-offs at ST ≥ 2, PD ≥ 1, and MRI synovitis and BME at both ≥ 1 and ≥ 2. RESULTS: This study included 39 patients (85% female, mean (SD) age = 51.6 (10.3)). Using MRI synovitis and BME grade ≥ 2 as the reference, PD had superior sensitivity (82%) and kappa agreement (k = 0.43) than swollen joint count (55%, k = 0.20), but similar high specificity (88%, 83%). ST and PD were often observed in clinically asymptomatic MTPJs. US detected very few MRI erosions, but several observed erosions corresponded to grade ≥ 2 MRI erosions. CONCLUSION: Clinical swelling and PD are highly specific for active inflammation in the MTPJs. US supplemented CE by allowing observation of subclinical inflammation and structural damage. Key Points • Ultrasonography detected many subclinical synovial inflammations in metatarsophalangeal joints (MTPJs), many confirmed by MRI • Ultrasonography may best be used clinically to supplement clinical examination by assessing non-swollen joints • Ultrasonography provided quick method of visualizing bone erosions that were grade ≥ 2 on MRI.

Pulmonary arterial hypertension screening practices in scleroderma patients among Canadian rheumatologists.

Background: Current international guidelines recommend annual screening for pulmonary arterial hypertension with transthoracic echocardiogram and pulmonary function testing in all patients with scleroderma (systemic sclerosis). Our objectives were to determine Canadian rheumatologists' screening practices for pulmonary arterial hypertension in patients with systemic sclerosis and identify reasons why current guideline recommendations may not be followed. Methods: A survey was emailed to all Canadian Rheumatology Association members. They self-identified as systemic sclerosis experts or non-experts and provided basic demographic data. Participants were asked how frequently they screened with transthoracic echocardiogram and pulmonary function testing and, if applicable, why they did not adhere to recommendations. Results: A total of 71 rheumatologists participated, of whom 43 identified as non-experts. Overall, 81.4% ordered annual transthoracic echocardiogram and 77.6% annual pulmonary function testing. Rates of annual transthoracic echocardiogram testing were similar between experts and non-experts, whereas experts ordered annual pulmonary function testing more often. Clinicians with a higher proportion of systemic sclerosis patients in their practice were more likely to follow guidelines. There was an inverse relationship between years in practice and adherence to screening guidelines. The most common reason for not following screening guidelines was disagreement with recommendations, followed by unfamiliarity with guidelines. Conclusions: Pulmonary arterial hypertension screening rates remain sub-optimal in Canada but have improved since 2012. Failure to adopt guidelines is due to rheumatologists disagreeing with or not knowing current recommendations. Future studies should examine why rheumatologists disagree with guidelines and how to improve awareness.

Outcomes and Findings of the International Rheumatoid Arthritis (RA) BIODAM Cohort for Validation of Soluble Biomarkers in RA.

OBJECTIVE: The Outcome Measures in Rheumatology Soluble Biomarker Working Group initiated an international, multicenter, prospective study, the Rheumatoid Arthritis (RA) BIODAM cohort, to generate resources for the clinical validation of candidate biomarkers predictive of radiographic progression. This first report describes the cohort, clinical outcomes, and radiographic findings. METHODS: Patients with RA from 38 sites in 10 countries starting or changing conventional synthetic disease-modifying antirheumatic drugs and/or starting tumor necrosis factor inhibitors were followed for 2 years. Participating physicians were required to adhere to a treat-to-target strategy. Biosamples (serum, urine) were acquired every 3 months, radiography of hands and feet every 6 months, and ultrasound of hands and feet every 3 months in a subset. Primary endpoint was radiographic progression by the Sharp/van der Heijde score. RESULTS: A total of 571 patients were recruited and 439 (76.9%) completed 2-year followup. At baseline, the majority was female (76%), mean age 55.7 years, and mean disease duration 6.5 years. Patients had a mean of 8.4 swollen and 13.6 tender joints, 44-joint count Disease Activity Score (DAS44) 3.8, 77.7% rheumatoid factor-positive or anticitrullinated protein antibody-positive. Percentage of patients in DAS and American College of Rheumatology remission at 2 years was 52.2% and 27.1%, respectively. Percentage of patients with radiographic progression (> 0.5) at 1 and 2 years was 38.2% and 59.9%, respectively. CONCLUSION: The RA BIODAM prospective study succeeded in generating an extensive list of clinical, imaging (2343 radiographs), and biosample (4638 sera) resources that will be made available to expedite the identification and validation of biomarkers for radiographic damage endpoints. (Clinicaltrials.gov: NCT01476956, clinicaltrials.gov/ct2/show/NCT01476956).

Adherence to Treat-to-target Management in Rheumatoid Arthritis and Associated Factors: Data from the International RA BIODAM Cohort.

OBJECTIVE: Compelling evidence supports a treat-to-target (T2T) strategy for optimal outcomes in rheumatoid arthritis (RA). There is limited knowledge regarding the factors that impede implementation of T2T, particularly in a setting where adherence to T2T is protocol-specified. We aimed to assess clinical factors that associate with failure to adhere to T2T. METHODS: Patients with RA from 10 countries who were starting or changing conventional synthetic disease-modifying antirheumatic drugs and/or starting tumor necrosis factor inhibitors were followed for 2 years. Participating physicians were required per protocol to adhere to the T2T strategy. Factors influencing adherence to T2T low disease activity (T2T-LDA; 44-joint count Disease Activity Score ≤ 2.4) were analyzed in 2 types of binomial generalized estimating equations models: (1) including only baseline features (baseline model); and (2) modeling variables that inherently vary over time as such (longitudinal model). RESULTS: A total of 571 patients were recruited and 439 (76.9%) completed 2-year followup. Failure of adherence to T2T-LDA was noted in 1765 visits (40.5%). In the baseline multivariable model, a high number of comorbidities (OR 1.10, 95% CI 1.02-1.19), smoking (OR 1.32, 95% CI 1.08-1.63) and high number of tender joints (OR 1.03, 95% CI 1.02-1.04) were independently associated with failure to implement T2T, while anticitrullinated protein antibody/rheumatoid factor positivity (OR 0.63, 95% CI 0.50-0.80) was a significant facilitator of T2T. Results were similar in the longitudinal model. CONCLUSION: Lack of adherence to T2T in the RA BIODAM cohort was evident in a substantial proportion despite being a protocol requirement, and this could be predicted by clinical features. [Rheumatoid Arthritis (RA) BIODAM cohort; ClinicalTrials.gov: NCT01476956].

Age-Associated Microbial Dysbiosis Promotes Intestinal Permeability, Systemic Inflammation, and Macrophage Dysfunction.

Levels of inflammatory mediators in circulation are known to increase with age, but the underlying cause of this age-associated inflammation is debated. We find that, when maintained under germ-free conditions, mice do not display an age-related increase in circulating pro-inflammatory cytokine levels. A higher proportion of germ-free mice live to 600 days than their conventional counterparts, and macrophages derived from aged germ-free mice maintain anti-microbial activity. Co-housing germ-free mice with old, but not young, conventionally raised mice increases pro-inflammatory cytokines in the blood. In tumor necrosis factor (TNF)-deficient mice, which are protected from age-associated inflammation, age-related microbiota changes are not observed. Furthermore, age-associated microbiota changes can be reversed by reducing TNF using anti-TNF therapy. These data suggest that aging-associated microbiota promote inflammation and that reversing these age-related microbiota changes represents a potential strategy for reducing age-associated inflammation and the accompanying morbidity.

TNF Drives Monocyte Dysfunction with Age and Results in Impaired Anti-pneumococcal Immunity.

Monocyte phenotype and output changes with age, but why this occurs and how it impacts anti-bacterial immunity are not clear. We found that, in both humans and mice, circulating monocyte phenotype and function was altered with age due to increasing levels of TNF in the circulation that occur as part of the aging process. Ly6C+ monocytes from old (18-22 mo) mice and CD14+CD16+ intermediate/inflammatory monocytes from older adults also contributed to this "age-associated inflammation" as they produced more of the inflammatory cytokines IL6 and TNF in the steady state and when stimulated with bacterial products. Using an aged mouse model of pneumococcal colonization we found that chronic exposure to TNF with age altered the maturity of circulating monocytes, as measured by F4/80 expression, and this decrease in monocyte maturation was directly linked to susceptibility to infection. Ly6C+ monocytes from old mice had higher levels of CCR2 expression, which promoted premature egress from the bone marrow when challenged with Streptococcus pneumoniae. Although Ly6C+ monocyte recruitment and TNF levels in the blood and nasopharnyx were higher in old mice during S. pneumoniae colonization, bacterial clearance was impaired. Counterintuitively, elevated TNF and excessive monocyte recruitment in old mice contributed to impaired anti-pneumococcal immunity since bacterial clearance was improved upon pharmacological reduction of TNF or Ly6C+ monocytes, which were the major producers of TNF. Thus, with age TNF impairs inflammatory monocyte development, function and promotes premature egress, which contribute to systemic inflammation and is ultimately detrimental to anti-pneumococcal immunity.

Effects of acute exercise on circulating endothelial and progenitor cells in children and adolescents with juvenile idiopathic arthritis and healthy controls: a pilot study.

BACKGROUND: Youth with juvenile idiopathic arthritis (JIA) may be at risk of poor cardiovascular health. Circulating endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) are markers of cardiovascular repair and damage, respectively, and respond to exercise. The objectives of this study were to compare resting levels of EPCs and CECs in JIA and controls, and to assess the effects of distinct types of exercise on EPCs and CECs in JIA and controls. METHODS: Seven youth with JIA and six controls completed 3 visits. First, aerobic fitness was assessed. Participants then performed either moderate intensity, continuous exercise (MICE) or high intensity, intermittent exercise (HIIE) on separate days. Blood samples were collected at the beginning (REST), mid-point (MID) and end of exercise (POST) for determination of EPCs (CD31(+)CD34(bright)CD45(dim)CD133(+)) and CECs (CD31(bright)CD34(+)CD45(-)CD133(-)) by flow cytometry. Between group differences in EPCs and CECs were examined using two-way ANOVA, followed by Tukey's HSD post hoc, where appropriate. Statistical significance set at p ≤ 0.05. RESULTS: Both EPCs and CECs were similar between groups at REST (p = 0.18-0.94). During MICE, EPCs remained unchanged in JIA (p = 0.95) but increased significantly at POST in controls (REST: 0.91 ± 0.55 × 10(6) cells/L vs. POST: 1.53 ± 0.36 × 10(6) cells/L, p = 0.04). Compared with controls, lower levels of EPCs were observed in JIA at MID (0.48 ± 0.50 × 10(6) cells/L vs. 1.10 ± 0.39 × 10(6) cells/L, p = 0.01) and POST (0.38 ± 0.34 × 10(6) cells/L vs. 1.53 ± 0.36 × 10(6) cells/L, p < 0.001) during MICE. No changes were detected in CECs with MICE in JIA and controls (p = 0.69). Neither EPCs nor CECs were modified with HIIE (p = 0.28-0.69). CONCLUSION: Youth with JIA demonstrated a blunted EPC response to MICE when compared with controls. Future work should examine factors that may increase or normalize EPC mobilization in JIA.