Best clinical practice in the treatment of juvenile systemic sclerosis: expert panel guidance - the result of the International Hamburg Consensus Meeting December 2022.

INTRODUCTION: Juvenile systemic sclerosis (jSSc) is an orphan disease with a prevalence of 3 in 1,000,000 children. Currently there is only one consensus treatment guideline concerning skin, pulmonary and vascular involvement for jSSc, the jSSc SHARE (Single Hub and Access point for pediatric Rheumatology in Europe) initiative, which was based on data procured up to 2014. Therefore, an update of these guidelines, with a more recent literature and expert experience, and extension of the guidance to more aspects of the disease is needed. AREAS COVERED: Treatment options were reviewed, and opinions were provided for most facets of jSSc including general management, some of which differs from adult systemic sclerosis, such as the use of corticosteroids, and specific organ involvement, such as skin, musculoskeletal, pulmonary, and gastroenterology. EXPERT OPINION: We are suggesting the treat to target strategy to treat early to prevent cumulative disease damage in jSSc. Conclusions are derived from both expert opinion and available literature, which is mostly based on adult systemic sclerosis (aSSc), given shared pathophysiology, extrapolation of results from aSSc studies was judged reasonable.

Comparison of treatments and outcomes of children with juvenile dermatomyositis followed at two European tertiary care referral centers.

OBJECTIVES: To compare the treatment approaches and disease outcomes of children with JDM followed in two European tertiary care peadiatric rheumatology centres. METHODS: The medical notes of patients with JDM seen at Istituto Giannina Gaslini (IGG) of Genoa, Italy or Great Ormond Street Hospital (GOSH) of London, UK between January 2000 and December 2015 within 6 months after disease onset and followed for at least 6 months were reviewed. Demographic, clinical and therapeutic data were collected. At each visit, the caring physician was asked to rate the disease state subjectively. RESULTS: A total of 127 patients were included, 88 at GOSH and 39 at IGG. At 24 months, the median values of muscle strength and disease activity were at the normal end of the scale and around three quarters of patients were said to have inactive disease. Also, at 2 years, 38.6% and 36% of British and Italian patients, respectively, had damage. Cyclophosphamide, azathioprine, infliximab, rituximab and mycophenolate mofetil were used more frequently by UK physicians, whereas ciclosporin, intravenous immunoglobulin and hydroxychloroquine were prescribed by Italian physicians. CONCLUSION: This study shows a significant difference in the choice of medications between pediatric rheumatologists practising in the two centres. Despite this, a high proportion of patients had inactive disease at 2 years and there was a low frequency of damage: modern treatments have improved outcomes.

Development and Testing of Reduced Versions of the Manual Muscle Test-8 in Juvenile Dermatomyositis.

OBJECTIVE: To develop and test shortened versions of the Manual Muscle Test-8 (MMT-8) in juvenile dermatomyositis (JDM). METHODS: Construction of reduced tools was based on a retrospective analysis of individual scores of MMT-8 muscle groups in 3 multinational datasets. The 4 and 6 most frequently impaired muscle groups were included in MMT-4 and MMT-6, respectively. Metrologic properties of reduced tools were assessed by evaluating construct validity, internal consistency, discriminant ability, and responsiveness to change. RESULTS: Neck flexors, hip extensors, hip abductors, and shoulder abductors were included in MMT-4, whereas MMT-6 also included elbow flexors and hip flexors. Both shortened tools revealed strong correlations with MMT-8 and other muscle strength measures. Correlations with other JDM outcome measures were in line with predictions. Internal consistency was good (0.88-0.96) for both MMT-4 and MMT-6. Both reduced tools showed strong ability to discriminate between disease activity states, assessed by the caring physician or a parent (P < 0.001), and between patients whose parents were satisfied or not satisfied with illness course (P < 0.001). Responsiveness to change (assessed by both standardized response mean and relative efficiency) of MMT-4 and, to a lesser degree, MMT-6, was slightly superior to that of MMT-8. CONCLUSION: Overall, the metrologic performance of MMT-4 and MMT-6 was comparable to that of the other established muscle strength tools, which indicates that they may be suitable for use in clinical practice and research, including clinical trials. The measurement properties of these tools should be further tested in other patient populations and evaluated prospectively.

Development and validation of a composite disease activity score for measurement of muscle and skin involvement in juvenile dermatomyositis.

OBJECTIVE: To develop a composite DAS for JDM and provide preliminary evidence of its validity. METHODS: The Juvenile DermatoMyositis Activity Index (JDMAI) is composed of four items: physician's global assessment of overall disease activity; parent's/child's global assessment of child's wellbeing; measurement of muscle strength; and assessment of skin disease activity. The score of the JDMAI is the arithmetic sum of the scores of each individual component. Six versions of the JDMAI were tested, which differed in the tools used to assess the third and fourth items. Validation procedures were conducted using three large multinational patient samples including a total of 627 patients. RESULTS: The JDMAI was found to possess face and content validity, good construct validity, satisfactory internal consistency (Cronbach's alpha = 0.58-0.89), fair responsiveness to clinically important change (standardized response mean = 0.82-3.12 among patients improved) and strong capacity to discriminate patients judged as being in the state of inactive disease or low, moderate or high disease activity by the physician (P < 0.001) or whose parents were satisfied or not satisfied with the course of their child's illness (P < 0.001). Overall, the six versions of the JDMAI showed similar metrological performances in validation analyses. CONCLUSION: The JDMAI was found to possess good measurement properties in a large population of patients with a wide range of disease activity, and is, therefore, suitable for use in both clinical and research settings. The final version of the JDMAI will be selected after its prospective validation.

Development and Testing of a Hybrid Measure of Muscle Strength in Juvenile Dermatomyositis for Use in Routine Care.

OBJECTIVE: To develop and test a hybrid measure of muscle strength for juvenile dermatomyositis (JDM), which is based on the combination of the Manual Muscle Testing in 8 muscles (MMT-8) and the Childhood Myositis Assessment Scale (CMAS) but is more comprehensive than the former and more feasible than the latter. METHODS: The hybrid MMT-8/CMAS (hMC) is composed of all 8 items of the MMT-8 and 3 items of the CMAS: time of head lift, assessment of abdominal muscles, and floor rise. The score ranges 0-100, with 100 indicating normal muscle strength. Validation procedures were conducted using 3 large multinational patient samples, including a total of 810 JDM patients. RESULTS: The hMC revealed face and content validity, good construct validity, excellent test-retest reliability (intraclass correlation coefficient = 0.99), and internal consistency (Cronbach's α = 0.94), strong responsiveness to clinical change over time (standardized response mean = 0.8 among patients judged as improved by the caring physician), and satisfactory capacity to discriminate patients judged as being in the states of inactive disease or low, moderate, or high disease activity by the physician (P < 0.001) or patients whose parents were satisfied or not satisfied with the illness course (P < 0.001). CONCLUSION: The hMC was found to possess good measurement properties in a large population of patients with a wide range of disease activity and severity. The new tool, which is primarily intended for use in routine clinical care, should be further tested in other populations of patients evaluated prospectively.

2016 ACR-EULAR adult dermatomyositis and polymyositis and juvenile dermatomyositis response criteria-methodological aspects.

Objective: The objective was to describe the methodology used to develop new response criteria for adult DM/PM and JDM. Methods: Patient profiles from prospective natural history data and clinical trials were rated by myositis specialists to develop consensus gold-standard ratings of minimal, moderate and major improvement. Experts completed a survey regarding clinically meaningful improvement in the core set measures (CSM) and a conjoint-analysis survey (using 1000Minds software) to derive relative weights of CSM and candidate definitions. Six types of candidate definitions for response criteria were derived using survey results, logistic regression, conjoint analysis, application of conjoint-analysis weights to CSM and published definitions. Sensitivity, specificity and area under the curve were defined for candidate criteria using consensus patient profile data, and selected definitions were validated using clinical trial data. Results: Myositis specialists defined the degree of clinically meaningful improvement in CSM for minimal, moderate and major improvement. The conjoint-analysis survey established the relative weights of CSM, with muscle strength and Physician Global Activity as most important. Many candidate definitions showed excellent sensitivity, specificity and area under the curve in the consensus profiles. Trial validation showed that a number of candidate criteria differentiated between treatment groups. Top candidate criteria definitions were presented at the consensus conference. Conclusion: Consensus methodology, with definitions tested on patient profiles and validated using clinical trials, led to 18 definitions for adult PM/DM and 14 for JDM as excellent candidates for consideration in the final consensus on new response criteria for myositis.

Comparison of clinical features and drug therapies among European and Latin American patients with juvenile dermatomyositis.

OBJECTIVES: To compare the demographic features, presenting manifestations, diagnostic investigations, disease course, and drug therapies of children with juvenile dermatomyositis (JDM) followed in Europe and Latin America. METHODS: Patients were inception cohorts seen between 1980 and 2004 in 27 paediatric rheumatology centres. The following information was collected through the review of patient charts: sex; age at disease onset; date of disease onset and diagnosis; onset type; presenting clinical features; diagnostic investigations; course type; and medications received during disease course. RESULTS: Four hundred and ninety patients (65.5% females, mean onset age 7.0 years, mean disease duration 7.7 years) were included. Disease presentation was acute or insidious in 57.1% and 42.9% of the patients, respectively. The course type was monophasic in 41.3% of patients and chronic polycyclic or continuous in 58.6% of patients. The more common presenting manifestations were muscle weakness (84.9%), Gottron's papules (72.9%), heliotrope rash (62%), and malar rash (56.7%). Overall, the demographic and clinical features of the 2 continental cohorts were comparable. European patients received more frequently high-dose intravenous methylprednisolone, cyclosporine, cyclophosphamide, and azathioprine, while methotrexate and antimalarials medications were used more commonly by Latin American physicians. CONCLUSIONS: The demographic and clinical characteristics of JDM are similar in European and Latin American patients. We found, however, several differences in the use of medications between European and Latin American paediatric rheumatologists.

Long-term outcome and prognostic factors of juvenile dermatomyositis: a multinational, multicenter study of 490 patients.

OBJECTIVE: To investigate the long-term outcome and prognostic factors of juvenile dermatomyositis (DM) through a multinational, multicenter study. METHODS: Patients consisted of inception cohorts seen between 1980 and 2004 in 27 centers in Europe and Latin America. Predictor variables were sex, continent, ethnicity, onset year, onset age, onset type, onset manifestations, course type, disease duration, and active disease duration. Outcomes were muscle strength/endurance, continued disease activity, cumulative damage, muscle damage, cutaneous damage, calcinosis, lipodystrophy, physical function, and health-related quality of life (HRQOL). RESULTS: A total of 490 patients with a mean disease duration of 7.7 years were included. At the cross-sectional visit, 41.2-52.8% of patients, depending on the instrument used, had reduced muscle strength/endurance, but less than 10% had severe impairment. Persistently active disease was recorded in 41.2-60.5% of the patients, depending on the activity measure used. Sixty-nine percent of the patients had cumulative damage. The frequency of calcinosis and lipodystrophy was 23.6% and 9.7%, respectively. A total of 40.7% of the patients had decreased functional ability, but only 6.5% had major impairment. Only a small fraction had decreased HRQOL. A chronic course, either polycyclic or continuous, consistently predicted a poorer outcome. Mortality rate was 3.1%. CONCLUSION: This study confirms the marked improvement in functional outcome of juvenile DM when compared with earlier literature. However, many patients had continued disease activity and cumulative damage at followup. A chronic course was the strongest predictor of poor prognosis. These findings highlight the need for treatment strategies that enable a better control of disease activity over time and the reduction of nonreversible damage.

Health-related quality of life of patients with juvenile dermatomyositis: results from the Pediatric Rheumatology International Trials Organisation multinational quality of life cohort study.

OBJECTIVE: To investigate the health-related quality of life (HRQOL) change over time, as measured by the Child Health Questionnaire (CHQ), and its determinants in patients with active juvenile dermatomyositis (DM). METHODS: We assessed patients with juvenile DM at both baseline and 6 months of followup, and healthy children age < or =18 years. Potential determinants of poor HRQOL included demographic data, physician's and parent's global assessments, muscle strength, functional ability as measured by the Childhood Health Assessment Questionnaire (C-HAQ), global disease activity assessments, and laboratory markers. RESULTS: A total of 272 children with juvenile DM and 2,288 healthy children were enrolled from 37 countries. The mean +/- SD CHQ physical and psychosocial summary scores were significantly lower in children with juvenile DM (33.7 +/- 11.7 versus 54.6 +/- 4.1) than in healthy children (45.1 +/- 9.0 versus 52 +/- 7.2), with physical well-being domains being the most impaired. HRQOL improved over time in responders to treatment and remained unchanged or worsened in nonresponders. Both physical and psychosocial summary scores decreased with increasing levels of disease activity, muscle strength, and parent's evaluation of the child's overall well-being. A C-HAQ score >1.6 (odds ratio [OR] 5.06, 95% confidence interval [95% CI] 2.03-12.59), child's overall well-being score >6.2 (OR 5.24, 95% CI 2.27-12.10), and to a lesser extent muscle strength and alanine aminotransferase level were the strongest determinants of poor physical well-being at baseline. Baseline disability and longer disease duration were the major determinants for poor physical well-being at followup. CONCLUSION: We found that patients with juvenile DM have a significant impairment in their HRQOL compared with healthy peers, particularly in the physical domain. Physical well-being was mostly affected by the level of functional impairment.

Quantitative assessments of the effects of a single exercise session on muscles in juvenile dermatomyositis.

OBJECTIVE: To investigate the short-term effects of exercise on muscle inflammation in children with juvenile dermatomyositis (juvenile DM). Magnetic resonance imaging (MRI), muscle strength, and blood parameters were used as outcome measures. METHODS: Children with active juvenile DM, inactive juvenile DM, and healthy children were assessed for muscle strength (using myometry) and function, and MRI T2-weighted relaxation time measurement; blood was obtained from patients with juvenile DM. A standardized physiotherapy-led exercise program was completed, and the MRI was performed immediately afterwards. All children were reassessed with myometry and MRI at 30 minutes and 60 minutes, and repeat blood tests were performed at 60 minutes for the patients with juvenile DM. RESULTS: Ten children with active juvenile DM, 10 with inactive juvenile DM, and 20 healthy controls completed the study. Muscle inflammation assessed by MRI, myometry, and blood parameters did not change significantly in response to exercise either immediately after or up to 60 minutes after the exercise program in any group. CONCLUSION: In the short term, a single bout of exercise does not change the degree of inflammation within the muscles of children with active or inactive juvenile DM or in healthy children. The data suggest that, at least in this time period, there is no evidence that exercise increases the inflammation within the muscles. We propose therefore that a moderate exercise program is safe for children with juvenile DM.