Disease activity trajectories from childhood to adulthood in the population-based Nordic juvenile idiopathic arthritis cohort.

OBJECTIVES: To identify long-term disease activity trajectories from childhood to adulthood by using the clinical Juvenile Arthritis Disease Activity Score (cJADAS10) in juvenile idiopathic arthritis (JIA). Second, to evaluate the contribution of the cJADAS10 components and explore characteristics associated with active disease at the 18-year follow-up. METHODS: Patients with onset of JIA in 1997-2000 were followed for 18 years in the population-based Nordic JIA cohort. We used a discrete mixture model for longitudinal clustering of the cJADAS10 and its components. We assessed factors potentially associated with higher scores on the patient's global assessment of well-being (PaGA) by hierarchical clustering and correlation analysis. RESULTS: Four disease activity trajectories were identified based on the cJADAS10 components among 427 patients. In trajectory-group 2, the PaGA and the physician's global assessment of disease activity (PhGA) increased significantly during the course, but not the active joint count. The increase in the PaGA was significantly higher than the increases in the PhGA and the active joint count (p<0.0001). A similar pattern was found among all the patients with active disease in the total cohort. Patients with higher PaGA scores had unfavourable scores on several other patient-reported outcomes. CONCLUSIONS: We have identified groups of patients based on long-term disease activity trajectories. In our study the PaGA was the most important driver of disease activity into adulthood assessed by cJADAS10. We need to better understand how our patients interpret global well-being and implement strategies to achieve inactive disease perceived both by the patient and the physician.

Body mass index is associated with health-related quality of life and disease characteristics in young adults with juvenile idiopathic arthritis.

BACKGROUND: There is a growing interest concerning the relationship between obesity and several medical conditions and inflammation. Nevertheless, there is a lack of studies regarding body mass index (BMI) among patients with juvenile idiopathic arthritis (JIA). Our aim was to investigate the impact of BMI on health-related quality of life (HRQoL) measured with a 36-Item Short Form Survey (SF-36), disease activity, and disability in young adults with JIA. METHODS: This study is a part of the population-based Nordic JIA cohort study. All newly diagnosed patients with JIA were recruited consecutively between 1997-2000 in specific regions in the Nordic countries. Patients in this sub-study were enrolled from 434 patients who attended their 18-year follow-up visit. Patients were classified according to the World Health Organization (WHO) into four groups based on their BMI. HRQoL, disease characteristics, disability, fatigue, sleep quality, physical activity, pain, comorbidities, and social status were assessed. RESULTS: Three hundred fifty-five patients from the original study cohort were enrolled in this study and 72% of them were female. Mean age was 23.9 (± SD 4.4) years. A significant relationship was found between the JIA categories and BMI groups (p = 0.014). A significant relationship was also found between BMI and disease activity scores (DAS28) (p = 0.028), disability (p < 0.001), pain (p = 0.013), fatigue (p = 0.035), and sleep quality (p = 0.044). Moreover, a significant relationship between BMI and HRQoL regarding bodily pain (p = 0.010) and general health (p = 0.048) was revealed when adjusted for sex, age, and JIA subtype. CONCLUSION: We discovered that BMI was significantly related to HRQoL, disease activity, and disability. BMI deserves more attention considering the treatment options and outcome of JIA in young adults.

Transitioning patients with juvenile idiopathic arthritis to adult care: the Nordic experience.

BACKGROUND: With juvenile idiopathic arthritis (JIA), there are several protocols and practices used worldwide for the transition from paediatric to adult care. In this study, we examined the transferral rates and disease activity after transition, as well as the disease- and health-related outcomes. We also introduce the transition practices employed in the Nordic countries. METHODS: The study population comprised 408 participants with a disease onset from 1997 to 2000 who attended an 18-year follow-up visit in this population-based Nordic JIA cohort study. The patients were retrospectively divided into three subgroups: Patients transferred directly from paediatric care to adult rheumatology care, patients referred there later, and patients never transferred during the 18-year follow-up period. RESULTS: One hundred and sixty-three (40%) JIA patients had been directly transferred to an adult clinic. The cumulative transition rate was 52%, but there were significant differences between the participating centres. Fifty patients had later been referred to an adult clinic. Among the 195 patients who had never been transferred, 39% were found to have disease activity at the study visit. CONCLUSION: This study highlights the need to reconsider transition practices to avoid our undesirable finding of patients with disease activity in JIA, but no appropriate health care follow-up.

Changing Patterns in Treatment, Remission Status, and Categories in a Long-Term Nordic Cohort Study of Juvenile Idiopathic Arthritis.

OBJECTIVE: To explore sustainability of achieved remission off medication and defined International League of Associations for Rheumatology (ILAR) categories in juvenile idiopathic arthritis (JIA) and describe the trajectory of disease course over time by comparing treatment, disease activity, and ILAR categories from baseline, 8 years, and 18 years after disease onset. METHODS: A total of 373 of the 510 included patients were initially recruited consecutive cases of JIA from the prospective, longitudinal, population-based Nordic JIA cohort with disease onset during 1997-2000 from Denmark, Norway, Sweden, and Finland in an 18-year follow-up study. Clinical data were collected consecutively at baseline, 8 years, and 18 years after disease onset and were evaluated regarding treatment, disease activity, and ILAR category. RESULTS: Significantly more patients (70%) were off medication after 18 years of follow-up compared to after 8 years (59.7%); nevertheless, the number of patients in remission had not increased (52% off medication versus 51% on medication). Twelve percent of patients changed ILAR category between 8 years and 18 years after disease onset. Almost half of the changes were due to updated information about heredity in a first-degree relative. In the same period, the psoriatic arthritis group increased significantly in number (P < 0.001), in contrast to the oligoarticular category, which decreased (P = 0.02). The undifferentiated group increased 24% from 8 to 18 years of follow-up; however, this increase was not significant (P = 0.06). CONCLUSION: In this Nordic JIA cohort study, the remission rate did not increase even though significantly more patients were off medication at the 18-year follow-up compared to at the 8-year follow-up after disease onset. The distribution of patients in the ILAR categories continued to change significantly throughout the 18-year study period.

Fatigue in young adults with juvenile idiopathic arthritis 18 years after disease onset: data from the prospective Nordic JIA cohort.

BACKGROUND: To study fatigue in young adults with juvenile idiopathic arthritis (JIA) 18 years after disease onset, and to compare with controls. METHODS: Consecutive children with onset of JIA between 1997 and 2000, from geographically defined areas of Norway, Sweden, Denmark and Finland were followed for 18 years in a close to population-based prospective cohort study. Clinical features, demographic and patient-reported data were collected. Inclusion criteria in the present study were a baseline visit 6 months after disease onset, followed by an 18-year follow-up with available self-reported fatigue score (Fatigue Severity Scale (FSS), 1-7). Severe fatigue was defined as FSS ≥4. For comparison, Norwegian age and sex matched controls were used. RESULTS: Among 377 young adults with JIA, 26% reported severe fatigue, compared to 12% among controls. We found higher burden of fatigue among participants with sleep problems, pain, poor health, reduced participation in school/work, physical disability, active disease, or use of disease-modifying anti-rheumatic drugs (DMARDs)/biologics/systemic steroids. In contrast, participants without these challenges, had fatigue scores similar to controls. Active disease assessed at all three time points (baseline, 8-year and 18-year follow-up) was associated with higher mean fatigue score and higher percentage of severe fatigue compared to disease courses characterized by periods of inactive disease. Predictors of fatigue at the 18-year follow-up were female sex and diagnostic delay of ≥6 months at baseline, and also pain, self-reported poor health, active disease, and previous/ongoing use of DMARDs/biologics at 8 years. CONCLUSIONS: Fatigue is a prominent symptom in young adults with JIA, with higher fatigue burden among participants with poor sleep, pain, self-reported health problems, active disease, or use of DMARDs/biologics. Participants without these challenges have results similar to controls. Patient- and physician-reported variables at baseline and during disease course predicted fatigue at 18-year follow-up.

Uveitis in Juvenile Idiopathic Arthritis: 18-Year Outcome in the Population-based Nordic Cohort Study.

PURPOSE: To assess the long-term outcome of uveitis in juvenile idiopathic arthritis (JIA). DESIGN: Population-based, multicenter, prospective JIA cohort, with a cross-sectional assessment of JIA-associated uveitis (JIA-U) 18 years after the onset of JIA. PARTICIPANTS: A total of 434 patients with JIA, of whom 96 had uveitis, from defined geographic areas of Denmark, Finland, Norway, and Sweden. METHODS: Patients with onset of JIA between January 1997 and June 2000 were prospectively followed for 18 years. Pediatric rheumatologists and ophthalmologists collected clinical and laboratory data. MAIN OUTCOME MEASURES: Cumulative incidence of uveitis and clinical characteristics, JIA and uveitis disease activity, ocular complications, visual outcome, and risk factors associated with the development of uveitis-related complications. RESULTS: Uveitis developed in 96 (22.1%) of 434 patients with JIA. In 12 patients (2.8%), uveitis was diagnosed between 8 and 18 years of follow-up. Systemic immunosuppressive medication was more common among patients with uveitis (47/96 [49.0%]) compared with patients without uveitis (78/338 [23.1%]). Active uveitis was present in 19 of 78 patients (24.4%) at the 18-year visit. Ocular complications occurred in 31 of 80 patients (38.8%). Short duration between the onset of JIA and the diagnosis of uveitis was a risk factor for developing ocular complications (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.8). Patients with a diagnosis of uveitis before the onset of JIA all developed cataract and had an OR for development of glaucoma of 31.5 (95% CI, 3.6-274). Presence of antinuclear antibodies (ANAs) was also a risk factor for developing 1 or more ocular complications (OR, 3.0; 95% CI, 1.2-7.7). Decreased visual acuity (VA) <6/12 was found in 12 of 135 eyes (8.9%) with uveitis, and 4 of 80 patients (5.0%) with JIA-U had binocular decreased VA <6/12. CONCLUSIONS: Our results suggest that uveitis screening should start immediately when the diagnosis of JIA is suspected or confirmed and be continued for more than 8 years after the diagnosis of JIA. Timely systemic immunosuppressive treatment in patients with a high risk of developing ocular complications must be considered early in the disease course to gain rapid control of ocular inflammation.

Pain sensitivity in young adults with juvenile idiopathic arthritis: a quantitative sensory testing study.

BACKGROUND: To study for the first-time, pain perception, pain sensitivity, and self-reported pain in young adults with long disease duration of juvenile idiopathic arthritis (JIA) compared with controls. METHODS: Children from Central Norway diagnosed with JIA between 1997 and 2004 were included consecutively in a population-based prospective study. Children with onset 1997-2000 were part of the Nordic JIA cohort. Controls were age- and sex-matched. In 2015-2017, study visits with investigator-blinded quantitative sensory testing (QST) comprising cold and warm detection thresholds (CDT/WDT), cold and heat pain thresholds (CPT/HPT), pressure pain threshold (PPT), and a suprathreshold heat pain test were performed. We constructed separate multilevel models for each variable of detection and pain thresholds with interaction between groups and site adjusted for the effect of age and sex. RESULTS: Among 96 young adults with JIA, 71% were female, median age was 22.7 years, disease duration was 16.1 years, and 47% had oligoarticular disease. Among 109 controls, 71% were female, and median age was 23.5 years. Participants with JIA had lower pressure pain thresholds (PPTs) (95% CI) compared to controls, upper limb 888 (846,930) versus 1029 (999,1059) kPa and lower limb 702 (670,734) versus 760 (726,794) kPa. Participants with inactive disease had the lowest PPTs and cold pain thresholds (CPTs), compared to those in remission off medication and those with active disease. Minor differences were found regarding CDT/WDT and CPT/HPT in JIA compared to controls. The median (IQR) temperature needed to evoke pain = 6 on a 0-10 numeric rating scale (NRS) in the suprathreshold heat pain tests were lower in JIA than in controls (46 °C (45-47 °C) versus 47 °C (46-48 °C)). We found no associations between self-reported pain and pain thresholds. CONCLUSIONS: Our results indicate for the first time that young adults with long disease duration of JIA may have altered pain perception and sensitivity compared to controls. A clinical implication may be the importance of early treatment to quickly achieve pain-free remission and avoid long-term pain sensitization.

Long-Term Outcomes in Juvenile Idiopathic Arthritis: Eighteen Years of Follow-Up in the Population-Based Nordic Juvenile Idiopathic Arthritis Cohort.

OBJECTIVE: The present study was undertaken to assess the long-term course, remission rate, and disease burden in juvenile idiopathic arthritis (JIA) 18 years after disease onset in a population-based setting from the early biologic era. METHODS: A total of 510 consecutive cases of JIA with disease onset between 1997 and 2000 from defined geographic regions in Denmark, Norway, Sweden, and Finland were prospectively included in this 18-year cohort study. At the follow-up visit, patient-reported demographic and clinical data were collected. RESULTS: The study included 434 (85%) of the 510 eligible JIA participants. The mean ± SD age was 24.0 ± 4.4 years. The median juvenile arthritis disease activity score in 71 joints (JADAS-71) was 1.5 (interquartile range [IQR] 0-5), with the enthesitis-related arthritis (ERA) category of JIA having the highest median score (4.5 [IQR 1.5-8.5], P = 0.003). In this cohort, 46% of patients still had active disease, and 66 (15%) were treated with synthetic disease-modifying antirheumatic drugs and 84 (19%) with biologics. Inactive disease indicated by a JADAS-71 score of <1 was seen in 48% of participants. Clinical remission off medication (CR) was documented in 33% of the participants with high variability among the JIA categories. CR was most often seen in persistent oligoarticular and systemic arthritis and least often in ERA (P < 0.001). CONCLUSION: A substantial proportion of the JIA cohort did not achieve CR despite new treatment options during the study period. The ERA category showed the worst outcomes, and in general there is still a high burden of disease in adulthood for JIA.

Longterm Outcomes of Temporomandibular Joints in Juvenile Idiopathic Arthritis: 17 Years of Followup of a Nordic Juvenile Idiopathic Arthritis Cohort.

OBJECTIVE: To determine the prevalence of orofacial symptoms, dysfunctions, and deformities of the temporomandibular joint (TMJ) in juvenile idiopathic arthritis (JIA) 17 years after disease onset. METHODS: Drawn from a prospective, population-based Nordic JIA cohort with disease onset from 1997 to 2000, 420 consecutive cases were eligible for orofacial evaluation of TMJ involvement. The followup visit included demographic data, a standardized clinical orofacial examination, and full-face cone-beam computed tomography (CBCT). For comparison, 200 age-matched healthy controls were used. RESULTS: Of 420 eligible participants with JIA, 265 (63%) were included (mean age 23.5 ± 4.2 yrs) and completed a standardized clinical orofacial examination. Of these, 245 had a full-face CBCT performed. At least 1 orofacial symptom was reported by 33%. Compared to controls, the JIA group significantly more often reported TMJ pain, TMJ morning stiffness, and limitation on chewing. Further, among participants reporting complaints, the number of symptoms was also higher in JIA. The mean maximal incisal opening was lower in the JIA group (p < 0.001), and TMJ pain on palpation was more frequent. Condylar deformities and/or erosions were observed in 61% as assessed by CBCT, showing bilateral changes in about 70%. Risk factors of condylar deformities were orofacial dysfunction or biologic treatment; enthesitis-related arthritis was protective. CONCLUSION: This study of the longterm consequences of TMJ involvement in a population-based JIA cohort reports persistence of comprehensive symptoms, dysfunctions, and damage of the TMJ into adulthood. We suggest interdisciplinary followup of JIA patients also in adulthood.

Validation of prediction models of severe disease course and non-achievement of remission in juvenile idiopathic arthritis: part 1-results of the Canadian model in the Nordic cohort.

BACKGROUND: Models to predict disease course and long-term outcome based on clinical characteristics at disease onset may guide early treatment strategies in juvenile idiopathic arthritis (JIA). Before a prediction model can be recommended for use in clinical practice, it needs to be validated in a different cohort than the one used for building the model. The aim of the current study was to validate the predictive performance of the Canadian prediction model developed by Guzman et al. and the Nordic model derived from Rypdal et al. to predict severe disease course and non-achievement of remission in Nordic patients with JIA. METHODS: The Canadian and Nordic multivariable logistic regression models were evaluated in the Nordic JIA cohort for prediction of non-achievement of remission, and the data-driven outcome denoted severe disease course. A total of 440 patients in the Nordic cohort with a baseline visit and an 8-year visit were included. The Canadian prediction model was first externally validated exactly as published. Both the Nordic and Canadian models were subsequently evaluated with repeated fine-tuning of model coefficients in training sets and testing in disjoint validation sets. The predictive performances of the models were assessed with receiver operating characteristic curves and C-indices. A model with a C-index above 0.7 was considered useful for clinical prediction. RESULTS: The Canadian prediction model had excellent predictive ability and was comparable in performance to the Nordic model in predicting severe disease course in the Nordic JIA cohort. The Canadian model yielded a C-index of 0.85 (IQR 0.83-0.87) for prediction of severe disease course and a C-index of 0.66 (0.63-0.68) for prediction of non-achievement of remission when applied directly. The median C-indices after fine-tuning were 0.85 (0.80-0.89) and 0.69 (0.65-0.73), respectively. Internal validation of the Nordic model for prediction of severe disease course resulted in a median C-index of 0.90 (0.86-0.92). CONCLUSIONS: External validation of the Canadian model and internal validation of the Nordic model with severe disease course as outcome confirm their predictive abilities. Our findings suggest that predicting long-term remission is more challenging than predicting severe disease course.

Complement lectin pathway protein levels reflect disease activity in juvenile idiopathic arthritis: a longitudinal study of the Nordic JIA cohort.

BACKGROUND: To determine the serum levels of the lectin pathway proteins early in the disease course and 17 years after disease onset and to correlate the protein levels to markers of disease activity in participants from a population-based Nordic juvenile idiopathic arthritis (JIA) cohort. Additionally, to assess the predictive value of lectin pathway proteins with respect to remission status. METHODS: A population-based cohort study of consecutive cases of JIA with a disease onset from 1997 to 2000 from defined geographical areas of Finland, Sweden, Norway and Denmark with 17 years of follow-up was performed. Clinical characteristics were registered and H-ficolin, M-ficolin, MASP-1, MASP-3, MBL and CL-K1 levels in serum were analyzed. RESULTS: In total, 293 patients with JIA were included (mean age 23.7 ± 4.4 years; mean follow-up 17.2 ± 1.7 years). Concentrations of the lectin protein levels in serum were higher at baseline compared to the levels 17 years after disease onset (p ≤ 0.006, n = 164). At baseline, the highest level of M-ficolin was observed in systemic JIA. Further, high M-ficolin levels at baseline and at 17-year follow-up were correlated to high levels of ESR. In contrast, high MASP-1 and MASP-3 tended to correlate to low ESR. CL-K1 showed a negative correlation to JADAS71 at baseline. None of the protein levels had prognostic abilities for remission status 17 years after disease onset. CONCLUSION: We hypothesize that increased serum M-ficolin levels are associated with higher disease activity in JIA and further, the results indicate that MASP-1, MASP-3 and CL-K1 are markers of inflammation.

Participation in school and physical education in juvenile idiopathic arthritis in a Nordic long-term cohort study.

BACKGROUND: The aim of the study was to describe school attendance and participation in physical education in school among children with juvenile idiopathic arthritis (JIA). METHODS: Consecutive cases of JIA from defined geographical areas of Finland, Sweden and Norway with disease onset in 1997 to 2000 were followed for 8 years in a multi-center cohort study, aimed to be as close to population-based as possible. Clinical characteristics and information on school attendance and participation in physical education (PE) were registered. RESULTS: Participation in school and in PE was lowest initially and increased during the disease course. Eight years after disease onset 228/274 (83.2%) of the children reported no school absence due to JIA, while 16.8% reported absence during the last 2 months due to JIA. Full participation in PE was reported by 194/242 (80.2%), partly by 16.9%, and none by 2.9%. Lowest participation in PE was found among children with ERA and the undifferentiated categories. Absence in school and PE was associated with higher disease activity measures at the 8-year visit. School absence > 1 day at baseline predicted use of disease-modifying anti-rheumatic drugs, including biologics (DMARDs) (OR 1.2 (1.1-1.5)), and non-remission off medication (OR 1.4 (1.1-1.7) 8 years after disease onset. CONCLUSION: School absence at baseline predicted adverse long-term outcome. In children and adolescents with JIA participation in school activities is mostly high after 8 years of disease. For the minority with low participation, special attention is warranted to promote their full potential of social interaction and improve long-term outcome.

Early Self-Reported Pain in Juvenile Idiopathic Arthritis as Related to Long-Term Outcomes: Results From the Nordic Juvenile Idiopathic Arthritis Cohort Study.

OBJECTIVE: To study self-reported pain early in the disease course of juvenile idiopathic arthritis (JIA) as a predictor of long-term disease outcomes. METHODS: Consecutive cases of JIA with disease onset from 1997 to 2000 from defined geographical areas of Norway, Sweden, Finland, and Denmark were prospectively enrolled in this population-based cohort study. Self-reported, disease-related pain was measured on a 10-cm visual analog scale (VAS pain). Inclusion criteria were a baseline visit with a pain score 6 months after disease onset, followed by an 8-year study visit. Remission was defined according to Wallace et al (2004) preliminary criteria. Functional disability was measured by the Childhood Health Assessment Questionnaire and the Child Health Questionnaire Parent Form if the child was age <18 years and by the Health Assessment Questionnaire if age ≥18 years. Damage was scored using the Juvenile Arthritis Damage Index. RESULTS: The final study cohort consisted of 243 participants, and 120 participants (49%) had oligoarticular onset. At baseline, 76% reported a VAS pain score >0 compared to 57% reporting at 8 years. Half of those who reported baseline pain also reported pain at 8 years but at a lower intensity. Compared to no pain, higher pain intensity at baseline predicted more pain at 8 years, more functional disability, more damage, and less remission without medication. Baseline pain predicted more use of disease-modifying antirheumatic drugs/biologics during the disease course. Participants with oligoarticular JIA reporting pain at baseline were more likely to develop extended oligoarticular JIA or other JIA categories with an unfavorable prognosis. CONCLUSION: Early self-reported, disease-related pain among children and adolescents with JIA is common and seems to predict persistent pain and unfavorable long-term disease outcomes.

Predicting unfavorable long-term outcome in juvenile idiopathic arthritis: results from the Nordic cohort study.

BACKGROUND: The aim was to develop prediction rules that may guide early treatment decisions based on baseline clinical predictors of long-term unfavorable outcome in juvenile idiopathic arthritis (JIA). METHODS: In the Nordic JIA cohort, we assessed baseline disease characteristics as predictors of the following outcomes 8 years after disease onset. Non-achievement of remission off medication according to the preliminary Wallace criteria, functional disability assessed by Childhood Health Assessment Questionnaire (CHAQ) and Physical Summary Score (PhS) of the Child Health Questionnaire, and articular damage assessed by the Juvenile Arthritis Damage Index-Articular (JADI-A). Multivariable models were constructed, and cross-validations were performed by repeated partitioning of the cohort into training sets for developing prediction models and validation sets to test predictive ability. RESULTS: The total cohort constituted 423 children. Remission status was available in 410 children: 244 (59.5%) of these did not achieve remission off medication at the final study visit. Functional disability was present in 111/340 (32.7%) children assessed by CHAQ and 40/199 (20.1%) by PhS, and joint damage was found in 29/216 (13.4%). Model performance was acceptable for making predictions of long-term outcome. In validation sets, the area under the curves (AUCs) in the receiver operating characteristic (ROC) curves were 0.78 (IQR 0.72-0.82) for non-achievement of remission off medication, 0.73 (IQR 0.67-0.76) for functional disability assessed by CHAQ, 0.74 (IQR 0.65-0.80) for functional disability assessed by PhS, and 0.73 (IQR 0.63-0.76) for joint damage using JADI-A. CONCLUSION: The feasibility of making long-term predictions of JIA outcome based on early clinical assessment is demonstrated. The prediction models have acceptable precision and require only readily available baseline variables. Further testing in other cohorts is warranted.