Experience with the use of mycophenolate mofetil in juvenile idiopathic inflammatory myopathies.

OBJECTIVE: The objective of this study was to evaluate the efficacy and safety of MMF in juvenile idiopathic inflammatory myopathies (JIIMs). METHODS: Patients diagnosed with JIIM and treated with MMF enrolled in the Juvenile Dermatomyositis Research Group (JDRG) in the UK or followed at the Giannina Gaslini Institute in Genoa, Italy, were included. The following information was collected retrospectively at MMF initiation, at 3, 6 and 12 months after treatment start, and at last follow-up visit: clinical manifestations, laboratory data, physicians' subjective assessment of disease activity, standardized outcome measures of muscle strength/endurance, cutaneous disease activity, physical function, global disease activity, cumulative damage, and ongoing treatment. RESULTS: Of the 29 patients included, 23 had juvenile DM and 6 had overlap myositis. During administration of MMF, improvement in measures of muscle strength, skin disease activity, and overall disease activity was seen, with an increase in the frequency of normal scores for Manual Muscle Test-8 from 50.0% to 83.3%, Childhood Myositis Activity Score from 53.5% to 88.9%, muscle component of DAS from 55.2% to 84.2%, skin component of DAS from 31.0% to 42.1%, visual analogue scale for skin disease activity from 25.0% to 47.4%, and visual analogue scale for overall disease activity from 7.1% to 42.1%. The number of patients with inactive disease increased from 10.3% at baseline to 68.5% at last follow-up. CS dose was significantly reduced, from 0.3 to 0.1 mg/kg/day. No relevant side effects were reported. CONCLUSION: Our experience suggests that MMF is a valuable therapeutic option for the management of JIIM.

A prediction rule for polyarticular extension in oligoarticular-onset juvenile idiopathic arthritis.

OBJECTIVES: To search for predictors of polyarticular extension in children with oligoarticular-onset juvenile idiopathic arthritis (JIA) and to develop a prediction model for an extended course. METHODS: The clinical charts of consecutive patients with oligoarticular-onset JIA and ≥2 years of disease duration were reviewed. Predictor variables included demographic data, number and type of affected joints, presence of iridocyclitis, laboratory tests including antinuclear antibodies, and therapeutic interventions in the first 6 months. Joint examinations were evaluated to establish whether after the first 6 months of disease patients had persistent or extended course (i.e. involvement of 4 or less, or 5 or more joints). Statistics included univariable and multivariable analyses. Regression coefficients (ß) of variables that entered the best-fitting logistic regression model were converted and summed to obtain a "prediction score" for an extended course. RESULTS: A total of 480 patients with a median disease duration of 7.4 years were included. 61.2% had persistent oligoarthritis, whereas 38.8% experienced polyarticular extension. On multivariable analysis, independent correlations with extended course were identified for the presence of ≥2 involved joints and a CRP >0.8 mg/dl in the first 6 months. The prediction score ranged from 0 to 6 and its cut-off that discriminated best between patients who had or did not have polyarticular extension was >1. Sensitivity and specificity were 59.6 and 79.8, respectively. CONCLUSIONS: The number of affected joints and the CRP level in the first 6 months were the strongest predictors of polyarticular extension in our children with oligoarticular-onset JIA.

Stratification of Patients With Sjögren's Syndrome and Patients With Systemic Lupus Erythematosus According to Two Shared Immune Cell Signatures, With Potential Therapeutic Implications.

OBJECTIVE: Similarities in the clinical and laboratory features of primary Sjögren's syndrome (SS) and systemic lupus erythematosus (SLE) have led to attempts to treat patients with primary SS or SLE with similar biologic therapeutics. However, the results of many clinical trials are disappointing, and no biologic treatments are licensed for use in primary SS, while only a few biologic agents are available to treat SLE patients whose disease has remained refractory to other treatments. With the aim of improving treatment selections, this study was undertaken to identify distinct immunologic signatures in patients with primary SS and patients with SLE, using a stratification approach based on immune cell endotypes. METHODS: Immunophentyping of 29 immune cell subsets was performed using flow cytometry in peripheral blood from patients with primary SS (n = 45), patients with SLE (n = 29), and patients with secondary SS associated with SLE (SLE/SS) (n = 14), all of whom were considered to have low disease activity or be in clinical remission, and sex-matched healthy controls (n = 31). Data were analyzed using supervised machine learning (balanced random forest, sparse partial least squares discriminant analysis), logistic regression, and multiple t-tests. Patients were stratified by K-means clustering and clinical trajectory analysis. RESULTS: Patients with primary SS and patients with SLE had a similar immunologic architecture despite having different clinical presentations and prognoses. Stratification of the combined primary SS, SLE, and SLE/SS patient cohorts by K-means cluster analysis revealed 2 endotypes, characterized by distinct immune cell profiles spanning the diagnoses. A signature of 8 T cell subsets that distinctly differentiated the 2 endotypes with high accuracy (area under the curve 0.9979) was identified in logistic regression and machine learning models. In clinical trajectory analyses, the change in damage scores and disease activity levels from baseline to 5 years differed between the 2 endotypes. CONCLUSION: These findings identify an immune cell toolkit that may be useful for differentiating, with high accuracy, the immunologic profiles of patients with primary SS and patients with SLE as a way to achieve targeted therapeutic approaches.

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.

Analysis of arthritis flares after achievement of inactive disease with methotrexate monotherapy in juvenile idiopathic arthritis.

OBJECTIVES: To investigate the frequency of arthritis flare and factors affecting occurrence of flare in children with juvenile idiopathic arthritis (JIA) who achieved inactive disease (ID) with methotrexate (MTX) monotherapy. METHODS: A total of 217 patients were included. The modality of treatment discontinuation, time of MTX withdrawal, and disease course were examined retrospectively. For each patient, the first episode of ID after MTX start was evaluated. Patient follow-up was censored at occurrence of flare or at last visit with persistent ID. RESULTS: 170 patients (78.3%) had arthritis flare after a median of 1.6 years, whereas 47 (21.7%) maintained ID until last visit, after a median of 3 years. 54.2% of patients had discontinued MTX after ID, whereas 45.8% were still receiving MTX at the time of study censoring. Among patients who had MTX withdrawn, the median interval between ID and MTX stop was 1.5 years. Occurrence of flare was more common in patients who were still receiving MTX at study censoring than in those who had discontinued MTX (p<0.001). Most patients (78.8%) had MTX tapered over time by increasing the interval between doses. Tapering modality was comparable between patients with flare and persistent ID. Only 7.7% of the patients had a biologic DMARD started at the time of flare. CONCLUSIONS: Our results confirm that children with JIA who achieve ID with MTX monotherapy have a high risk of arthritis flare. The risk of flare was independent of withdrawal strategy. Most flare episodes were not treated with biologic therapy.

Presentation, Treatment Response and Short-Term Outcomes in Paediatric Multisystem Inflammatory Syndrome Temporally Associated with SARS-CoV-2 (PIMS-TS).

The novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the pathogen responsible for Coronavirus Disease 2019 (COVID-19). Whilst most children and young people develop mild symptoms, recent reports suggest a novel paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS). Case definition and classification are preliminary, treatment is empiric and disease-associated outcomes are unclear. Here, we report 29 patients with PIMS-TS who were diagnosed, admitted and treated in the English North West between March and June 2020. Consistent with patterns observed internationally, cases peaked approximately 4 weeks after the initial surge of COVID-19-like symptoms in the UK population. Clinical symptoms included fever (100%), skin rashes (72%), cardiovascular involvement (86%), conjunctivitis (62%) and respiratory involvement (21%). Some patients had clinical features partially resembling Kawasaki disease (KD), toxic shock syndrome and cytokine storm syndrome. Male gender (69%), black, Asian and other minority ethnicities (BAME, 59%) were over-represented. Immune modulating treatment was used in all, including intravenous immunoglobulin (IVIG), corticosteroids and cytokine blockers. Notably, 32% of patients treated with IVIG alone went into remission. The rest required additional treatment, usually corticosteroids, with the exception of two patients who were treated with TNF inhibition and IL-1 blockade, respectively. Another patient received IL-1 inhibition as primary therapy, with associated rapid and sustained remission. Randomized and prospective studies are needed to investigate efficacy and safety of treatment, especially as resources of IVIG may be depleted secondary to high demand during future waves of COVID-19.

A prediction rule for lack of achievement of inactive disease with methotrexate as the sole disease-modifying antirheumatic therapy in juvenile idiopathic arthritis.

BACKGROUND: To investigate the frequency of achievement of inactive disease (ID) in children with juvenile idiopathic arthritis (JIA) treated with methotrexate (MTX) as the sole disease-modifyng antirheumatic (DMARD) therapy and to develop a prediction model for lack of attainment of ID. METHODS: The clinical charts of consecutive patients started with MTX as the sole DMARD between 2000 and 2013 were reviewed. Patient follow-up was censored at first episode of ID or, in case ID was not reached, at last follow-up visit or when a biologic DMARD was prescribed. The characteristic at MTX start of patients who achieved or did not achieve ID were compared with univariate and multivariable analyses. Regression coefficients (ß) of variables that entered the best-fitting logistic regression model were converted and summed to obtain a "prediction score" for lack of achievement of ID. RESULTS: A total of 375 patients were included in the study. During MTX administration, 8.8% were given systemic corticosteroids and 44.1% intra-articular corticosteroids. After MTX start, 229 (61%) patients achieved ID after a median of 1.7 years, whereas 146 patients (39%) did not reach ID after a median of 1.2 years. On multivariable analysis, independent correlations with lack of achievement of ID were identified for the disease categories of systemic arthritis, enthesitis-related arthritis (ERA) and polyarthritis and C-reactive protein (CRP) >  1.4 mg/dl. The prediction score ranged from 0 to 3 and its cutoff that discriminated best between patients who achieved or did not achieve ID was > 0.5. The categories of systemic arthritis or ERA, both of which had a score greater than 0.5, were sufficient alone to predict a lower likelihood to reach ID. Polyarthritis and increased CRP, whose score was 0.5, assumed a predictive value only when present in association. CONCLUSION: A conventional treatment regimen based on MTX as the sole DMARD led to achievement of ID in a sizeable proportion of children with JIA. Our findings help to outline the characteristics of patients who may deserve a synthetic DMARD other than MTX or the introduction of a biologic DMARD from disease outset.

Paediatric and adolescent rheumatic diseases: measures of disease activity.

Juvenile idiopathic arthritis, juvenile systemic lupus erythematosus and juvenile dermatomyositis are rare, chronic, multi-systemic rheumatic disorders that can be associated with significant morbidity, not only during childhood, but lifelong. Dedicated disease activity and damage assessment tools are essential to guide clinical management and perform multicentre clinical trials to ensure the best possible care and outcome for children with rheumatic diseases using an evidence-based, treat-to-target approach. This article summarizes the outcome measures most commonly used in paediatric rheumatology.

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.

Multi-centre national audit of juvenile localised scleroderma: describing current UK practice in disease assessment and management.

OBJECTIVE: To describe current United Kingdom practice in assessment and management of patients with juvenile localised scleroderma (JLS) compared to Paediatric Rheumatology European Society (PRES) scleroderma working party recommendations. METHODS: Patients were included if they were diagnosed with JLS and were under the care of paediatric rheumatology between 04/2015-04/2016. Retrospective data was collected in eleven UK centres using a standardised proforma and collated centrally. RESULTS: 149 patients were included with a median age of 12.5 years. The outcome measures recommended by the PRES scleroderma working party were not utilised widely. The localised scleroderma cutaneous assessment tool was only used in 37.6% of patients. Screening for extracutaneous manifestations did not meet recommendations that patients with head involvement have regular screening for uveitis and baseline magnetic resonance imaging (MRI) brain: only 38.5% of these patients were ever screened for uveitis; 71.2% had a MRI brain. Systemic treatment with disease-modifying anti-rheumatic drugs (DMARDs) or biologics was widely used (96.0%). In keeping with the recommendations, 95.5% of patients were treated with methotrexate as first-line therapy. 82.6% received systemic corticosteroids and 34.2% of patients required two or more DMARDs/biologics, highlighting the significant treatment burden. Second-line treatment was mycophenolate mofetil in 89.5%. CONCLUSION: There is wide variation in assessment and screening of patients with JLS but a consistent approach to systemic treatment within UK paediatric rheumatology. Improved awareness of PRES recommendations is required to ensure standardised care. As recommendations are based on low level evidence and consensus opinion, further studies are needed to better define outcome measures and treatment regimens for JLS.

Juvenile dermatomyositis: novel treatment approaches and outcomes.

PURPOSE OF REVIEW: The aim of this article is to provide a summary of the recent therapeutic advances and the latest research on outcome measures for juvenile dermatomyositis (JDM). RECENT FINDINGS: Several new international studies have developed consensus-based guidelines on diagnosis, outcome measures and treatment of JDM to standardize and improve patient care. Myositis-specific antibodies together with muscle biopsy histopathology may help the clinician to predict disease outcome. A newly developed MRI-based scoring system has been developed to standardize the use of MRI in assessing disease activity in JDM. New data regarding the efficacy and safety of rituximab, especially for skin disease, and cyclophosphamide in JDM support the use of these medications for severe refractory cases. SUMMARY: International network studies, new biomarkers and outcome measures have led to significant progress in understanding and managing the rare inflammatory myositis conditions such as JDM.

Innovative Research Design to Meet the Challenges of Clinical Trials for Juvenile Dermatomyositis.

PURPOSE OF REVIEW: This paper aims to provide a summary of the recent therapeutic advances and the latest research on outcome measures for clinical trials in juvenile dermatomyositis (JDM). RECENT FINDINGS: Recent randomized controlled trials (RCTs) have demonstrated the superiority of the combination of prednisone with methotrexate over other conventional therapies and the potential effectiveness of rituximab in refractory cases. A multinational project has led to develop new criteria for the definition of minimal, moderate, and major improvement in future JDM clinical trials. This effort has been paralleled by the establishment of criteria for clinically inactive disease. The validation of the first composite disease activity score for JDM is in progress. The new outcome measures will increase the reliability of assessment of clinical response in JDM clinical trials and foster future multinational RCTs aimed to investigate novel treatment strategies for refractory forms of JDM.

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.

Granulomatosis with polyangiitis mimicking infective endocarditis in an adolescent male.

Granulomatosis with polyangiitis (GPA) is a rare but serious small vessel vasculitis with heterogeneous clinical presentation ranging from mainly localised disease with a chronic course, to a florid, acute small vessel vasculitic form characterised by severe pulmonary haemorrhage and/or rapidly progressive vasculitis or other severe systemic vasculitic manifestations. Cardiac involvement is, however, uncommon in the paediatric population. We report a case of a 16-year-old male who presented with peripheral gangrene and vegetation with unusual location on the supporting apparatus of the tricuspid valve, initially considered to have infective endocarditis but ultimately diagnosed with GPA. We provide an overview of the limited literature relating to cardiac involvement in GPA, and the diagnostic challenge relating to infective endocarditis in this context, especially focusing on the interpretation of the antineutrophil cytoplasmic antibody (ANCA) and the characteristic clinical features to identify in order to promptly recognise GPA, since timely diagnosis and treatment are essential for this potentially life-threatening condition.

Takayasu arteritis in childhood: retrospective experience from a tertiary referral centre in the United Kingdom.

INTRODUCTION: Takayasu arteritis (TA) is an idiopathic large-vessel vasculitis affecting the aorta and its major branches. Although the disease rarely affects children, it does occur, even in infants. The objective of this study was to evaluate the clinical features, disease activity, treatment and outcome of childhood TA in a tertiary UK centre. METHODS: We analysed a retrospective case series of children fulfilling the TA classification criteria of the European League against Rheumatism, the Paediatric Rheumatology European Society and the Paediatric Rheumatology International Trials Organisation. Data regarding demographics, clinical features, treatments and outcomes were recorded. Descriptive statistics are expressed as median and range. Fisher's exact test was used for group comparisons. The Paediatric Vasculitis Activity Score (PVAS), Paediatric Vasculitis Damage Index (PVDI), Disease Extent Index-Takayasu (DEI.Tak) and Indian Takayasu Arteritis Activity Score (ITAS2010) were calculated retrospectively. RESULTS: A total of 11 children (64% female) with age at diagnosis of 11.8 (1.3 to 17) years were identified over a 23-year period. The median time to diagnosis was 17 (0 to 132) months. The most common clinical features at presentation were arterial hypertension (72.7%), systemic features (36%) and cardiovascular (45%), neurological (36%), pulmonary (27%), skin (9%), renal (9%) and gastrointestinal (9%) involvement. At presentation, PVAS was 5/63 (1 to 13); DEI.Tak was 7/81 (2 to 12) and ITAS2010 was 9/57 (6 to 20). Treatment included corticosteroids (81.8%), combined with methotrexate in most cases (72.7%). Cyclophosphamide (36.4%) and biologic agents (45.5%) were reserved for severe and/or refractory cases. PVDI at latest follow-up was 5.5/72 (3 to 15). Mortality was 27%. Young age at disease onset (<5 years old) and permanent PVDI scores≥3 were significantly associated with mortality risk (P=0.024). CONCLUSION: TA is a rare and potentially life-threatening large-vessel vasculitis. Improved awareness of TA is essential to secure a timely diagnosis. Although the evidence base for the treatment of TA in children is weak, we found that it is essential to treat it aggressively because our data emphasise that the mortality and morbidity in the paediatric population remains high.

Glucocorticoids in juvenile idiopathic arthritis.

Glucocorticoid (GC) drugs are a potent and rapidly effective therapeutic option for the treatment of juvenile idiopathic arthritis (JIA). These medications are mainly used for the management of the extra-articular features of systemic-onset disease. A course of low-dose prednisone may be considered for achieving a rapid disease control in patients with severe polyarthritis refractory to other therapies or while awaiting the full therapeutic effect of a recently initiated disease-modifying antirheumatic drug or biologic agent. Short-term systemic GC administration may also be indicated for chronic iridocyclitis unresponsive to topical therapy. The general objective of GC therapy is to limit the maximum dose and exposure to the highest doses to what is needed to achieve disease control, and then to gradually taper the dose until the minimum level sufficient to maintain disease quiescence over time is reached. High-dose intravenous 'pulse' methylprednisolone administration is sometimes chosen to treat the most severe or acute disease manifestations of systemic JIA, particularly macrophage activation syndrome. Intra-articular GC injection is a safe and rapidly effective treatment for synovitis in children with chronic arthritis. Triamcinolone hexacetonide is the optimal GC preparation for pediatric patients. Local injection therapy is used most frequently to treat oligoarthritis, but the strategy of performing multiple injections to induce disease remission, while simultaneously initiating therapy with second-line or biologic agents, has also been proposed for children with polyarticular JIA. Administration of GCs is associated with potentially deleterious adverse effects, some of which can be irreversible. This highlights the need of a judicious use of these medications and careful monitoring of their toxicity. The recently published recommendations for the management of JIA provide useful guidance to the clinicians for the administration of GCs in children with chronic arthritis.

Advances in biomarkers for paediatric rheumatic diseases.

The search for biomarkers in paediatric rheumatic diseases, particularly juvenile idiopathic arthritis (JIA), childhood lupus nephritis (LN), and juvenile idiopathic inflammatory myopathies (JIIMs) is attracting increased interest. In JIA, a number of biomarkers have shown potential for predicting clinical phenotype, disease activity and severity, clinical remission and relapse, response to treatment, and disease course over time. In systemic JIA, measurement of biomarkers that reflect the degree of activation and expansion of T cells and macrophages might be helpful for detecting subclinical macrophage activation syndrome. Urine biomarkers for childhood LN hold promise for facilitating early diagnosis and improving disease monitoring and assessment of response to therapy. Myositis-specific autoantibodies define distinct serological subgroups of JIIMs, albeit with similar clinical features, responses to therapy, and prognoses. Use of biomarkers may potentially help to avoid invasive procedures, such as renal biopsy in systemic lupus erythematosus and muscle biopsy in juvenile dermatomyositis. Incorporation of effective and reliable biomarkers into routine practice might facilitate adoption of a stratified approach to investigation and management, foster the implementation of research into the design of personalized and targeted therapies, and ultimately lead to more rational and effective clinical care.

Development and initial validation of composite parent- and child-centered disease assessment indices for juvenile idiopathic arthritis.

OBJECTIVE: To develop and validate a parent-centered and a child-centered composite disease assessment index for juvenile idiopathic arthritis (JIA): the Juvenile Arthritis Parent Assessment Index (JAPAI) and the Juvenile Arthritis Child Assessment Index (JACAI), respectively. METHODS: The JAPAI and the JACAI include 4 measures: parent/child rating of overall well-being, pain, physical function, and health-related quality of life (HRQOL). Validation analyses were conducted on nearly 5,000 patients and included assessment of construct validity, discriminant validity, responsiveness to change, and reliability. Besides the 4-item version, a 3-item version of both indices, which did not include HRQOL, was tested. RESULTS: The JAPAI and the JACAI demonstrated good construct validity, yielding high correlations with the Juvenile Arthritis Disease Activity Score and moderate correlations with physician global rating and joint counts. Correlations obtained for the JAPAI and the JACAI and for the 4-item and the 3-item versions were comparable. Factorial analysis by principal component analysis showed that both indices are monodimensional. Both the JAPAI and JACAI discriminated well between different disease states and courses and between different levels of American College of Rheumatology Pediatric criteria in a clinical trial, and revealed fair responsiveness to clinical change. Internal consistency was satisfactory, with a Cronbach's alpha of >0.80 in all but 1 of the patient samples tested. CONCLUSION: The JAPAI and the JACAI were found to be valid instruments for assessment of disease status in JIA and suitable surrogates of physicians' evaluations. Both indices are potentially applicable in clinical practice, observational studies, and therapeutic trials.