Our knowledge of the role of cytokines in pathologic conditions has increased considerably with the emergence of molecular and genetic studies, particularly in the case of autoinflammatory monogenic ...diseases. Many rare disorders, considered orphan until recently, are directly related to abnormal gene regulation, and the treatment with biologic agents (biologics) targeting cytokine receptors, intracellular signaling or specific cytokines improve the symptoms of an increasing number of chronic inflammatory diseases. As it is currently impossible to systematically conduct genetic studies for all patients with autoinflammatory and autoimmune diseases, the evaluation of cytokines can be seen as a simple, less time consuming, and less expensive alternative. This approach could be especially useful when the diagnosis of syndromes of diseases of unknown etiology remains problematic. The evaluation of cytokines could also help avoid the current trial‐and‐error approach, which has the disadvantages of exposing patients to ineffective drugs with possible unnecessary side effects and permanent organ damages. In this review, we discuss the various possibilities, as well as the limitations of evaluating the cytokine profiles of patients suffering from autoinflammatory and autoimmune diseases, with methods such as direct detection of cytokines in the plasma/serum or following ex vivo stimulation of PBMCs leading to the production of their cytokine secretome. The patients’ secretome, combined with biomarkers ranging from genetic and epigenetic analyses to immunologic biomarkers, may help not only the diagnosis but also guide the choice of biologics for more efficient and rapid treatments.
Review on the use of cytokines to help diagnose and guide treatments of patients suffering from autoinflammatory and autoimmune diseases.
Objective
To determine early outcomes and early improvements in a prospective inception cohort of children with juvenile idiopathic arthritis (JIA) treated with current standard therapies.
Methods
...Patients selected were enrolled in an inception cohort of JIA, the Research in Arthritis in Canadian Children Emphasizing Outcomes Study. The juvenile rheumatoid arthritis core criteria set measures were completed at enrollment and 6 months later. Frequencies of normal values for each of the core set measures and the American College of Rheumatology (ACR) Pediatric 30, 50, and 70 (Pedi 70) criteria response rates achieved at 6 months after enrollment were calculated for each JIA‐onset subtype group.
Results
Among 354 patients in the study, the median interval between diagnosis and enrollment was 0.7 months. At 6 months after enrollment, median values of active joint counts were highest in patients with rheumatoid factor (RF)–positive polyarthritis (4) and RF‐negative polyarthritis (2), but were 0 or 1 for other subtypes. Fifty percent or more of patients with oligoarthritis, systemic arthritis, enthesitis‐related arthritis, and undifferentiated arthritis had no active joints, and the ACR Pedi 70 criteria response rate was 48% or more in those with oligoarthritis, RF‐negative polyarthritis, and systemic arthritis.
Conclusion
With current management strategies in clinical practice, improvement in disease activity was noted in considerable proportions of patients in all of the JIA subtype groups, but low levels of disease activity persisted in many. We expect that these early outcomes will prove to be significant predictors of long‐term outcomes.
To describe clinical outcomes of juvenile idiopathic arthritis (JIA) in a prospective inception cohort of children managed with contemporary treatments.
Children newly diagnosed with JIA at 16 ...Canadian paediatric rheumatology centres from 2005 to 2010 were included. Kaplan-Meier survival curves for each JIA category were used to estimate probability of ever attaining an active joint count of 0, inactive disease (no active joints, no extraarticular manifestations and a physician global assessment of disease activity <10 mm), disease remission (inactive disease >12 months after discontinuing treatment) and of receiving specific treatments.
In a cohort of 1104 children, the probabilities of attaining an active joint count of 0 exceeded 78% within 2 years in all JIA categories. The probability of attaining inactive disease exceeded 70% within 2 years in all categories, except for RF-positive polyarthritis (48%). The probability of discontinuing treatment at least once was 67% within 5 years. The probability of attaining remission within 5 years was 46-57% across JIA categories except for polyarthritis (0% RF-positive, 14% RF-negative). Initial treatment included joint injections and non-steroidal anti-inflammatory drugs for oligoarthritis, disease-modifying antirheumatic drugs (DMARDs) for polyarthritis and systemic corticosteroids for systemic JIA.
Most children with JIA managed with contemporary treatments attain inactive disease within 2 years of diagnosis and many are able to discontinue treatment. The probability of attaining remission within 5 years of diagnosis is about 50%, except for children with polyarthritis.
To describe probabilities and characteristics of disease flares in children with juvenile idiopathic arthritis (JIA) and to identify clinical features associated with an increased risk of flare.
We ...studied children in the Research in Arthritis in Canadian Children emphasizing Outcomes (ReACCh-Out) prospective inception cohort. A flare was defined as a recurrence of disease manifestations after attaining inactive disease and was called significant if it required intensification of treatment. Probability of first flare was calculated with Kaplan-Meier methods, and associated features were identified using Cox regression.
1146 children were followed up a median of 24 months after attaining inactive disease. We observed 627 first flares (54.7% of patients) with median active joint count of 1, physician global assessment (PGA) of 12 mm and duration of 27 weeks. Within a year after attaining inactive disease, the probability of flare was 42.5% (95% CI 39% to 46%) for any flare and 26.6% (24% to 30%) for a significant flare. Within a year after stopping treatment, it was 31.7% (28% to 36%) and 25.0% (21% to 29%), respectively. A maximum PGA >30 mm, maximum active joint count >4, rheumatoid factor (RF)-positive polyarthritis, antinuclear antibodies (ANA) and receiving disease-modifying antirheumatic drugs (DMARDs) or biological agents before attaining inactive disease were associated with increased risk of flare. Systemic JIA was associated with the lowest risk of flare.
In this real-practice JIA cohort, flares were frequent, usually involved a few swollen joints for an average of 6 months and 60% led to treatment intensification. Children with a severe disease course had an increased risk of flare.
To (i) validate the JIA parent global assessment (parent global) as a health-related quality of life (HRQoL) instrument; (ii) evaluate measurement properties of accepted HRQoL measures relative to ...those of the parent global; and (iii) assess causal pathways determining parent global scores.
Data from the Research in Arthritis in Canadian Children emphasizing outcomes (ReACCh-Out) cohort were used. Measurement properties were assessed in 344 patients at enrolment and 6 months later. Causal pathways were tested by structural equation modelling to understand root causes and mediators leading to parent global scores.
Construct validity was supported by Spearman correlations of 0.53-0.70 for the parent global with the Juvenile Arthritis Quality of Life Questionnaire, Quality of My Life health scale (HRQoML), Pediatric Quality of Life Inventory (PedsQL)-Parent, and Child Health Questionnaire (CHQ)-Physical. Exceptions were PedsQL-Child (0.44) and CHQ-Psychosocial (0.31). Correlations were lower (0.14-0.49) with disease activity measures (physician global assessment of disease activity, active joint count, ESR). Responsiveness of the parent global to improvement according to parent ratings (0.51) was acceptable and within the range (0.32-0.71) of that of other measures. Reliability estimates and measurement errors for all measures were unsatisfactory, likely due to the prolonged time between assessments. Causal pathways for the parent global matched those previously reported for HRQoML.
Our results offer support for the parent global as a valid measure of HRQoL for JIA. If confirmed, existing studies using the parent global may be re-interpreted, enhancing our knowledge of HRQoL in children with JIA.
Abstract
Objective
To identify early predictors of disease activity at 18 months in JIA using clinical and biomarker profiling.
Methods
Clinical and biomarker data were collected at JIA diagnosis in ...a prospective longitudinal inception cohort of 82 children with non-systemic JIA, and their ability to predict an active joint count of 0, a physician global assessment of disease activity of ≤1 cm, and inactive disease by Wallace 2004 criteria 18 months later was assessed. Correlation-based feature selection and ReliefF were used to shortlist predictors and random forest models were trained to predict outcomes.
Results
From the original 112 features, 13 effectively predicted 18-month outcomes. They included age, number of active/effused joints, wrist, ankle and/or knee involvement, ESR, ANA positivity and plasma levels of five inflammatory biomarkers (IL-10, IL-17, IL-12p70, soluble low-density lipoprotein receptor-related protein 1 and vitamin D), at enrolment. The clinical plus biomarker panel predicted active joint count = 0, physician global assessment ≤ 1, and inactive disease after 18 months with 0.79, 0.80 and 0.83 accuracy and 0.84, 0.83, 0.88 area under the curve, respectively. Using clinical features alone resulted in 0.75, 0.72 and 0.80 accuracy, and area under the curve values of 0.81, 0.78 and 0.83, respectively.
Conclusion
A panel of five plasma biomarkers combined with clinical features at the time of diagnosis more accurately predicted short-term disease activity in JIA than clinical characteristics alone. If validated in external cohorts, such a panel may guide more rationally conceived, biologically based, personalized treatment strategies in early JIA.
Objective
Undervaluing the effectiveness of conventional treatments may lead to overtreatment with biologic medications in children with juvenile idiopathic arthritis (JIA). Using data from a ...nationwide inception cohort and strict methods to control bias, the aim of our study was to estimate the real‐world effectiveness of simple JIA treatment strategies recommended in current guidelines.
Methods
Children with JIA who were recruited at 16 Canadian centers from 2005 to 2010 were followed for up to 5 years. For each child, all observed treatment changes over time were assessed by independent physicians using prospectively collected data and published response criteria. Success was defined as attainment of inactive disease or maintenance of this state when stepping down treatment; minimally active disease was deemed acceptable for children with polyarticular JIA. Success rates were calculated for treatments tried ≥25 times, and logistic regression analysis identified features associated with success.
Results
A total of 4,429 treatment episodes were observed in 1,352 children. Nonsteroidal antiinflammatory drug (NSAID) monotherapy was attempted 697 times, mostly as initial treatment when <5 joints were involved, with a 54.4% success rate (95% confidence interval 95% CI 50.3–58.6). NSAIDs plus joint injections had a 64.7% success rate (95% CI 59.8–69.7). Adding methotrexate to NSAIDs and/or joint injections (attempted 566 times) had a 60.5% success rate (95% CI 55.7–65.3). In adjusted analyses, each additional active joint reduced chances of success for treatment with NSAIDs (odds ratio OR 0.90 95% CI 0.85–0.94) and for methotrexate combinations (OR 0.96 95% CI 0.94–0.99). Each additional year after disease onset reduced chances of success for treatment with methotrexate combinations (OR 0.83 95% CI 0.72–0.95).
Conclusion
These real‐world effectiveness estimates show that conventional nonbiologic treatment strategies that are recommended in current guidelines are effective in achieving treatment targets in many children with JIA.
Objective
To estimate the impact of enthesitis on patient‐reported outcomes in children with juvenile idiopathic arthritis (JIA), irrespective of JIA category.
Methods
Children enrolled in the ...Research in Arthritis in Canadian Children Emphasizing Outcomes cohort were studied. Entheseal tenderness by physician examination in 33 defined locations, Juvenile Arthritis Quality of Life Questionnaire (JAQQ), Quality of My Life (QoML) Questionnaire, Childhood Health Assessment Questionnaire (C‐HAQ), and a pain visual analog scale were completed at enrollment, every 6 months for 2 years, and then yearly up to 5 years. Analyses consisted of descriptive statistics, linear mixed models for longitudinal data, and analysis of covariance.
Results
Among 1,371 patients followed for a median of 35.3 months (interquartile range 22.1, 49.2), 214 (16%) had enthesitis, of whom 137 (64%) were classified as having enthesitis‐related arthritis. After adjusting for JIA category and covariates, children with enthesitis reported higher JAQQ (mean raw score 2.71 versus 2.16, adjusted difference 0.41 points; 95% confidence interval 95% CI 0.22, 0.59), higher C‐HAQ (0.47 versus 0.31, adjusted difference 0.14 points; 95% CI 0.07, 0.22), higher pain (3.01 versus 1.68, adjusted difference 0.94 points; 95% CI 0.64, 1.25), and lower QoML (7.02 versus 8.23, adjusted difference –0.80 points; 95% CI –1.09, –0.51) scores than children without enthesitis. These differences persisted up to 5 years.
Conclusion
Children with enthesitis, regardless of JIA category, report worse patient‐reported outcomes than those without enthesitis. Thus, enthesitis should be assessed in all children with JIA.
Abstract
Objective
To identify discrete clusters comprising clinical features and inflammatory biomarkers in children with JIA and to determine cluster alignment with JIA categories.
Methods
A ...Canadian prospective inception cohort comprising 150 children with JIA was evaluated at baseline (visit 1) and after six months (visit 2). Data included clinical manifestations and inflammation-related biomarkers. Probabilistic principal component analysis identified sets of composite variables, or principal components, from 191 original variables. To discern new clinical-biomarker clusters (clusters), Gaussian mixture models were fit to the data. Newly-defined clusters and JIA categories were compared. Agreement between the two was assessed using Kruskal–Wallis analyses and contingency plots.
Results
Three principal components recovered 35% (three clusters) and 40% (five clusters) of the variance in patient profiles in visits 1 and 2, respectively. None of the clusters aligned precisely with any of the seven JIA categories but rather spanned multiple categories. Results demonstrated that the newly defined clinical-biomarker lustres are more homogeneous than JIA categories.
Conclusion
Applying unsupervised data mining to clinical and inflammatory biomarker data discerns discrete clusters that intersect multiple JIA categories. Results suggest that certain groups of patients within different JIA categories are more aligned pathobiologically than their separate clinical categorizations suggest. Applying data mining analyses to complex datasets can generate insights into JIA pathogenesis and could contribute to biologically based refinements in JIA classification.
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