Aging and interferon gamma response drive the phenotype of neutrophils in the inflamed joint

Objectives: Neutrophils are typically the most abundant leukocyte in arthritic synovial fluid. We sought to understand changes that occur in neutrophils as they migrate from blood to joint. Methods: We performed RNA sequencing of neutrophils from healthy human blood, arthritic blood, and arthritic synovial fluid, comparing transcriptional signatures with those from murine K/BxN serum transfer arthritis. We employed mass cytometry to quantify protein expression and sought to reproduce the synovial fluid phenotype ex vivo in cultured healthy blood neutrophils. Results: Blood neutrophils from healthy donors and patients with active arthritis exhibited largely similar transcriptional signatures. By contrast, synovial fluid neutrophils exhibited more than 1,600 differentially expressed genes. Gene signatures identified a prominent response to interferon gamma (IFNγ), as well as to tumor necrosis factor, interleukin 6, and hypoxia, in both humans and mice. Mass cytometry also found healthy and arthritic donor blood neutrophils largely indistinguishable but revealed a range of neutrophil phenotypes in synovial fluid defined by downregulation of CXCR1 and upregulation of FcγRI, HLA-DR, PD-L1, ICAM-1 and CXCR4. Reproduction of key elements of this signature in cultured blood neutrophils required both IFNγ and prolonged culture. Conclusions: Circulating neutrophils from arthritis patients resemble those from healthy controls, but joint fluid cells exhibit a network of changes, conserved across species, that implicate IFNγ response and aging as complementary drivers of the synovial neutrophil phenotype.

Tocilizumab in Systemic Juvenile Idiopathic Arthritis: Response Differs by Disease Duration at Medication Initiation and by Phenotype of Disease

Objective: We performed a single-center retrospective study to determine the different efficacy of tocilizumab (TCZ) in the early and late stages and in three phenotypic subgroups (monocyclic, polycyclic, and persistent) of systemic juvenile idiopathic arthritis (sJIA).Methods: Clinical and serological parameters of 77 sJIA patients treated by TCZ were collected from November 1, 2013 to May 1, 2019. Patients were grouped based on the duration group A < 6 months (n = 41) and group B > 6 months (n = 36) and divided into three phenotypes: monocyclic (n = 12), polycyclic (n = 14), and persistent (n = 51) course.Results: At baseline, group A had pronounced ESR, fever less active arthritis than group B (p < 0.05). After 12 weeks of therapy, TCZ alleviated fever, ESR, CRP, and systemic-onset juvenile arthritis disease activity score-27 (sJADAS27) in both group A and group B (p>0.05), while the efficacy of TCZ in relieving active arthritis in group A was better than that in group B (p<0.05). After 1 year of TCZ therapy, it showed that patients with monocyclic phenotype had the highest clinical response rate (91.7%, odds ratio = 0, 95% CI: 24–24, p = 0.00), followed by the polycyclic (28.6%, odds ratio = 2.1, 95% CI: 10.5–18.8, p = 0.00) and the persistent course (9.8%, odds ratio = 1.2, 95% CI: 9.5–13.8, p = 0.00).Conclusion: TCZ can quickly relieve fever and inflammation, especially when patients have less active arthritis with shorter disease duration. The long-term efficacy of TCZ is related to the phenotypes, among which the monocyclic is the best, and the persistent is the worst.

A Novel Algorithm using Within-leg Calibration for Enhanced Accuracy of Detection of Arthritis by Infrared Thermal Imaging in Children

Objective To standardize and improve the accuracy of detection of arthritis by thermal imaging. Methods Children with clinically active arthritis in the knee or ankle, as well as healthy controls, were enrolled to the development cohort and another group of children with knee symptoms were enrolled to the validation cohort. Ultrasound was performed for the arthritis subgroup for the development cohort. Joint exam by certified rheumatologists was used as a reference for the validation cohort. Infrared thermal data were analyzed using a custom software. Temperature after within-limb calibration (TAWiC) was defined as the temperature differences between joint and ipsilateral midtibia. TAWiC of knees and ankles was evaluated using ANOVA across subgroups. Optimal thresholds were determined by receiver operating characteristic (ROC) analysis using Youden index. Results There were significant differences in mean and 95th TAWiC of knee in anterior, medial, lateral views, and of ankles in anterior view, between inflamed and uninflamed counterparts (p<0.05). The area under the curve (AUC) was higher by 36% when using TAWiCKnee than those when using absolute temperature. Within validation cohort, the sensitivity of accurate detection of arthritis in knee using both mean and 95th TAWiC from individual views or combined all 3 views ranged from 0.60 to 0.70 and the specificity was greater than 0.90 in all views. Conclusion Children with active arthritis or tenosynovitis in knees or ankles exhibited higher TAWiC than healthy joints. Our validation cohort study showed promise of the clinical utility of infrared thermal imaging for arthritis detection.

The value of the patient global health assessment in polyarticular juvenile idiopathic arthritis: a nested cohort study

Objective The objectives were: 1) to explore the discordance between the Patient Global Health Assessment (PtGA) scores, the Physician Global Health Assessment (PhGA) scores, and Pain scores; and 2) to explore whether the PtGA during disease remission is associated with future disease flare in pJIA. Methods Data from an NIH funded clinical trial (NCT00792233) evaluating flare were used (N = 137). PtGA, PhGA, and Pain scores were assessed. Flare was defined as any active arthritis. Spearman’s correlation coefficients were calculated, and multivariable logistic regression was performed. Results 122 patients had records of flare status, of which 63 developed flare, and 42 of these patients had a visit immediately prior to flare. For study subjects with a visit immediately prior to flare, the PtGA, pain scores, and PhGA all increased at time of flare. For every unit increase in PtGA and Pain scores, there was a 9% and 23% higher odds of developing flare, respectively (p = 0.76, p = 0.40). For every unit increase in the PhGA score, there was a substantially lower odds of developing flare (p = 0.05). Conclusion Our results demonstrate that the PtGA and Pain scores are strongly correlated with each other and increased at the visit prior to flare, while the PhGA scores are not. Further, the PtGA and Pain score have some predictive value for flare, while the PhGA does not. These findings highlight the value of patient input in medical care and decision-making, and support the development and use of more sophisticated PROs in the care of JIA patients.

OP0166 DISEASE ACTIVITY IN CHILDREN WITH JUVENILE IDIOPATHIC ARTHRITIS AFTER SIMULTANEOUS PCV13 AND HIB VACCINATION: A COHORT STUDY

Background:The safety of vaccination of children with rheumatic diseases is determined not only by the risk of adverse events but also by the risk of exacerbation of the disease. The simultaneous administration of several vaccines can increase the likelihood of these events.Objectives:To evaluate the clinical and laboratory signs of disease activity in children with juvenile idiopathic arthritis (JIA) after simultaneous vaccination against pneumococcal and Haemophilus influenzae type b (Hib) infections.Methods:We included hospitalized patients with JIA ages 2 through 18 without serious comorbidity, immunized with polysaccharide conjugate vaccines against pneumococcal (PCV13) and Hib infections. Vaccines were administered (0.5 ml each) concurrently subcutaneously into the deltoid area. In all children before and 3 weeks after vaccination, clinical (joints with active arthritis, uveitis activity) and laboratory signs (increased ESR, concentrations of highly sensitive C-reactive protein – hsCRP, and calprotectin) of JIA activity were assessed. Serum hsCRP and calprotectin were quantified by ELISA. The upper limit of the reference interval for hsCRP was considered (according to the manufacturer’s instructions) a value of 8.2 mg/L, for calprotectin – 2.9 μg/ml, and for ESR – > 10 mm/h.Results:The study included 430 patients with JIA (girls 60.9%), median (IQR) age – 11.1 years (7.3 to 14.4), onset of JIA – 4.7 years (2.4 to 8.6). Patients with persistent oligoarticular JIA numbered 149 (34.7%), polyarticular RF-negative – 148 (34.4%), systemic – 101 (23.4%), enthesitis-related – 20 (4.7%), and polyarticular RF-positive JIA – 12 (2.8%). Biologic disease-modifying antirheumatic drugs (DMARDs) were administered to 278 (64.7%), non-biologic DMARDs (mostly methotrexate) – 282 (65.6%), corticosteroids – 45 (10.5%), and NSAIDs – 18 (4.2%) patients. Three weeks after vaccination, out of 100 (23.3%) patients with initially active joints, signs of active arthritis remained in 96 patients, of which 16 patients had a decrease in the median (IQR) number of active joints by 4 (2 to 8). Among patients without active joints at baseline, signs of active arthritis were not subsequently detected. Before vaccination, 9 patients had uveitis in the exacerbation phase, 7 - in the subactive phase, and 41 - in the remission phase. After vaccination, exacerbation of uveitis persisted in 4 patients. There were no new cases of uveitis or its exacerbation. The dynamics of laboratory signs of JIA activity are presented in Table 1. Initially, the high concentration of calprotectin was found in 191 (44.4%) patients, and after vaccination – in 220 (51.2%) patients; the difference was 6.7% (95% CI 1.0 - 12.5); hsCRP - in 34 (7.9%) and 51 (11.9%) patients; the difference was 4.0% (95% CI 0.6 - 7.3); high ESR – in 76 (17.7%) and 41 (9.5%) patients; the difference was -8.1% (95% CI -11.6 to -4.7), respectively. An independent predictor of new cases of high concentration of hsCRP (n = 36), but not new cases of high concentration of calprotectin (n = 94), was the initial number of joints with active arthritis – odds ratio 2.37 (95% CI 1.14 - 4.93).Table 1.Laboratory signs of JIA activity after simultaneous administration of vaccines against pneumococcal (PCV13) and Hib-infectionsVariablesBaselineAfter 3 weeksRatio*p**Geometric mean (95% CI)Calprotectin, μg/ml2.93 (2.70 – 3.17)3.15 (2.92 – 3.40)1.08 (0.99 – 1.17)0.087hsCRP, mg/L0.69 (0.60 – 0.78)0.79 (0.69 – 0.90)1.15 (0.99 – 1.33)0.073ESR, mm/h4.4 (4.0 – 4.8)3.7 (3.4 – 4.0)0.84 (0.78 – 0.90)0.001Note. CI – confidence interval. * Ratios of paired observations (95% CI). ** P-value calculated in paired samples t-test.Conclusion:Simultaneous vaccination against pneumococcal (PCV13) and Hib-infections in children with JIA produced no negative dynamics of the traditional indicators of disease activity (joint activity, uveitis, high ESR). At the same time, 3 weeks after vaccination, an increase in the concentration of calprotectin and hsCRP was found in a small number of patients (<10%).Disclosure of Interests:None declared

The Development of Extra-Articular Manifestations in Children With Enthesitis-Related Arthritis: Natural Course or Different Disease Entity?

Introduction: Enthesitis-related Arthritis (ERA) is a specific category of juvenile idiopathic arthritis (JIA) characterized by axial and/or peripheral arthritis, and enthesitis, although other different extra-articular manifestations may encompass its clinical spectrum.Materials and Methods: In order to examine if ERA-JIA with extra-articular involvement may represent a different entity from ERA without extra-articular involvement, we performed a retrospective, observational, monocentric study, in a cohort of ERA patients followed between 2001 and September 2020 at the Pediatric Rheumatology Unit of Meyer Children Hospital of Florence. We analyzed the demographic, clinical, laboratory and imaging data at the disease onset, as well as after 3, 6, and 12 months follow up.Results: We have enrolled 53 patients, 33 males. At the time of diagnosis, average age was 10.9 years, 53 patients had active arthritis and 25 active enthesitis. The middle foot involvement was present in 20 patients. Twenty-five children achieved clinical remission on medication. Extra-articular manifestations were observed in 14 patients, of whom 3 had inflammatory bowel disease, 5 uveitis, one uveitis associated with Crohn disease, 4 SAPHO syndrome, one celiac disease. The cohort was stratified according to the presence/absence of extra-articular manifestations. It was observed that middle foot involvement was more frequent in patients with no extra-articular manifestations (18/39 vs. 2/14; χ2 = 4.45, p = 0.05). Additionally, patients presenting extra-articular manifestation needed more frequently (12/14 vs. 21/39, χ2= 4.45, p = 0.05), and preciously (months: 3.7 ± 5.4 vs. 16.7 ± 26.5, p = 0.02), treatment with biologic agents. Finally, these patients achieved belatedly (months: 31.6 ± 32.3 vs. 22.9 ± 18.3, p = 0.01) and less frequently (3/14 vs. 22/39; χ2= 5.50, p = 0.03) the clinical remission on medication. Eventually, extra-articular involvement inversely correlated with the middle-foot arthritis (ρs −0.29, p = 0.03), the chance to achieve remission on medication (ρs −0.31 e p = 0.02), as well as the chance to keep overall remission, with and without medication (ρs −0.28, p = 0.04).Conclusion: In our cohort, children diagnosed with ERA-JIA at the onset of disease and then developed extra-articular manifestations show the absence of middle foot involvement and worse prognosis with an early need for the use of biologic agents, and overall low chance to achieve remission.

Pharmacological modulation of T cell immunity results in long-term remission of autoimmune arthritis

Chronic inflammatory diseases like rheumatoid arthritis are characterized by a deficit in fully functional regulatory T cells. DNA-methylation inhibitors have previously been shown to promote regulatory T cell responses and, in the present study, we evaluated their potential to ameliorate chronic and acute animal models of rheumatoid arthritis. Of the drugs tested, decitabine was the most effective, producing a sustained therapeutic effect that was dependent on indoleamine 2,3-dioxygenase (IDO) and was associated with expansion of induced regulatory T cells, particularly at the site of disease activity. Treatment with decitabine also caused apoptosis of Th1 and Th17 cells in active arthritis in a highly selective manner. The molecular basis for this selectivity was shown to be ENT1, a nucleoside transporter, which facilitates intracellular entry of the drug and is up-regulated on effector T cells during active arthritis. It was further shown that short-term treatment with decitabine resulted in the generation of a population of regulatory T cells that were able to suppress arthritis upon adoptive transfer. In summary, a therapeutic approach using an approved drug is described that treats active inflammatory disease effectively and generates robust regulatory T cells with the IDO-dependent capacity to maintain remission.

Response to treatment with intra-articular triamcinolone hexacetonide and triamcinolone acetonide in oligo articular juvenile idiopathic arthritis

Background Oligo-articular juvenile idiopathic arthritis (Oligo JIA) is the most common subtype of juvenile idiopathic arthritis. Intra-articular corticosteroid (IAC) injection is a mainstay treatment of oligo JIA providing pain relief, improving mobility and preventing further joint destruction in the majority of patients. In 2015, production of triamcinolone hexacetonide (TH) an intra-articular corticosteroid was discontinued in the United States leading to use of triamcinolone acetonide (TA) as an alternative. In this study, we compared response to treatment in children with oligo JIA who underwent therapy with intra-articular TA and TH injection. Methods Our study is a retrospective chart review of children with oligo JIA who were treated with IAC injections with TH between January 2012 and June 2015 and TA between J uly 2015 and December 2018. The two groups were followed at John R. Oishei Children’s Hospital of Buffalo and were evaluated for response to treatment, side effects and predictors of response including duration of disease before treatment, erythrocyte sedimentation rate (ESR), and c-reactive protein (CRP). Response to treatment was defined as at least 6 months follow up without evidence of active arthritis in injected joints. Patients were considered to be non-responders if they continued to show active arthritis during their first follow up after joint injection. The primary objective was to evaluate whether there was a significant difference in rate of response between TH and TA. Results Forty-nine patients, 38 female and 11 male with oligo JIA were included in the study. The average age was 6.7 years. A total of 111 joints were injected includin g 78 knees, 13 ankles, 9 wrists, 4 hips, 4 elbows, 2 TMJ and one subtalar joint. In the TA group, 49% (29/59) did not show response to injection compared to 27% (14/52) in the TH group. After 6 months, response rates were better for individuals injected with TH compared to TA (73% vs. 51%). In general, response to intra-articular TH was superior to TA with P = .016 using chi-square test of independence. This difference in outcome was not influenced by other variables such as duration of illness before treatment (P value 0.784) or elevated ESR and CRP. No difference in side effects between the two groups were noted. Conclusion Our results in conjunction with prior published data suggests that TH intra-articular joint injection in oligo JIA is superior to TA, although future controlled trials are necessary for confirmation. An effective, long lasting treatment can have a great impact on the outcome of these children.

Comparison of Bone Scintigraphy and PET/CT for the Evaluation of Disease Activity in Patients with Rheumatoid Arthritis: Application of Bone Scintigraphy

Background: We aimed to compare the reliability of bone scintigraphy (BS) and fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)–derived parameters in the detection of active arthritis in 28-joint areas and evaluate the reliability of joint counts between BS and clinical assessment in patients with rheumatoid arthritis (RA). Methods: We enrolled 106 patients (67 in the development group and 39 in the validation groups) with active RA who underwent BS, 18F-FDG PET/computed tomography (CT), and clinical evaluation of disease activity. We compared the results of BS-derived joint assessment with those of PET-derived and clinical joint assessments. Subsequently we developed a disease activity score (DAS) using BS-positive joints and validated it in an independent group.Results: The number of BS-positive joints in 28-joint areas significantly correlated with the swollen /tender joint counts (SJC/TJC) and PET-derived joint counts. A BS uptake score of 2 (strong positive) was significantly more sensitive compared with a BS uptake score of 1 (weak positive) in detecting a PET-positive joint among the 28-joints. After conducting multivariate analyses including erythrocyte sediment rate (ESR) and patient global assessment (PGA) in addition to BS-derived parameters, BS/DAS was obtained as follows: 0.056 × number of BS-positive joints in 28 joints + 0.012 × ESR + 0.030 × PGA. A significant correlation between BS/DAS and DAS28-ESR was confirmed in the validation group. Conclusion: Strong positive uptake of BS is sensitive and reproducible for the detection of active joints, and can complement the clinical assessment of disease activity in RA.

Chlamydia pecorum–Induced Arthritis in Experimentally and Naturally Infected Sheep

Chlamydia pecorum is an obligate intracellular pathogen with a wide host range including livestock such as sheep, cattle, goats, and pigs as well as wildlife species such as koalas. Chlamydial polyarthritis is an economically important disease resulting in swollen joints, lameness, stiffness, and weight loss in young sheep. In the present study, tissues from sheep experimentally or naturally infected with Chlamydia pecorum were assessed by histopathology and immunohistochemistry. Carpal, hock, and stifle joints as well as spleen, liver, kidney, lymph nodes, lung, and brain of 35 sheep from different inoculation groups were available. Two different C. pecorum strains (IPA and E58), different routes of administration (intraarticular or intravenous), UVA-irradiated IPA strain, and corresponding noninfected control groups were investigated. Similar investigations on tissues from 5 naturally infected sheep were performed. The most obvious inflammatory lesions were observed in synovial tissues and, notably, in the renal pelvis from the experimentally infected group and naturally infected animals. This resulted in chronic or chronic-active arthritis and pyelitis. Intralesional chlamydial inclusions could be demonstrated by immunohistochemistry in both tissues. Immunohistochemical evaluation of the presence and distribution of macrophages, T and B cells in synovial tissues revealed macrophages as the most prevalent inflammatory cell population. Previous observations indicated that C. pecorum isolates can infect circulating monocytes. Together with the finding of the histological lesions in synovial tissues and internal organs alongside the presence of C. pecorum DNA, these observations suggest chlamydial arthritis in lambs is the result of hematogeneous spread of C. pecorum.