Evaluation of the reliability of the Cutaneous Dermatomyositis Disease Area and Severity Index and the Cutaneous Assessment Tool-Binary Method in juvenile dermatomyositis among paediatric dermatologists, rheumatologists and neurologists.

BACKGROUND: The Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) and Cutaneous Assessment Tool-Binary Method (CAT-BM) have been shown to be reliable and valid outcome measures to assess cutaneous disease in adult dermatomyositis (DM) and juvenile DM (JDM), respectively. OBJECTIVES: This study compared the CDASI and CAT-BM for use by paediatric dermatologists, paediatric rheumatologists and paediatric neurologists in patients with JDM. METHODS: Five paediatric dermatologists, five paediatric rheumatologists and five paediatric neurologists each evaluated 14 patients with JDM using the CDASI, CAT-BM, and skin Physician Global Assessment (PGA) scales. Inter-rater reliability, intra-rater reliability, construct validity and completion time were compared. RESULTS: Inter-rater reliability for CDASI activity and damage scores was good to moderate for paediatric dermatologists and rheumatologists, but poor for paediatric neurologists. The inter-rater reliability for CAT-BM activity scores was moderate for paediatric dermatologists and rheumatologists, but poor for paediatric neurologists and poor across all specialties for damage scores. Intra-rater reliability for the CDASI and CAT-BM activity and damage scores was moderate to excellent for paediatric dermatologists, rheumatologists and neurologists. Strong associations were found between skin PGA activity and damage scores and CDASI or CAT-BM activity and damage scores, respectively (P < 0·002). The CDASI had a mean completion time of 5·4 min compared with that for the CAT-BM of 3·1 min. CONCLUSIONS: Our data confirm the reliability of the CDASI activity and damage scores and the CAT-BM activity scores when used by paediatric dermatologists and rheumatologists in assessing JDM. Significant variation existed in the paediatric neurologists' scores.

The juvenile idiopathic inflammatory myopathies: pathogenesis, clinical and autoantibody phenotypes, and outcomes.

The aim of this review was to summarize recent advances in the understanding of the clinical and autoantibody phenotypes, their associated outcomes and the pathogenesis of the juvenile idiopathic inflammatory myopathies (JIIMs). The major clinical and autoantibody phenotypes in children have many features similar to those in adults, and each has distinct demographic and clinical features and associated outcomes. The most common myositis autoantibodies in JIIM patients are anti-p155/140, anti-MJ and anti-MDA5. Higher mortality has been associated with overlap myositis as well as with the presence of anti-synthetase and anti-MDA5 autoantibodies; a chronic illness course and lipodystrophy have been associated with anti-p155/140 autoantibodies; and calcinosis has been associated with anti-MJ autoantibodies. Histologic abnormalities of JIIMs detectable on muscle biopsy have also been correlated with myositis-specific autoantibodies; for example, patients with anti-MDA5 show low levels of inflammatory infiltrate and muscle damage on biopsy. The first genome-wide association study of adult and juvenile dermatomyositis revealed three novel genetic associations, BLK, PLCL1 and CCL21 and confirmed that the human leucocyte antigen region is the primary risk region for juvenile dermatomyositis. Here, we review the well-established pathogenic processes in JIIMs, including the type 1 interferon and endoplasmic reticulum stress pathways. Several novel JIIM-associated inflammatory mediators, such as the innate immune system proteins, myeloid-related peptide 8/14, galectin 9 and eotaxin, have emerged as promising biomarkers of disease. Advances in our understanding of the phenotypes and pathophysiology of the JIIMs are leading to better tools to help clinicians stratify and treat these heterogeneous disorders.

Genome-wide association study identifies HLA 8.1 ancestral haplotype alleles as major genetic risk factors for myositis phenotypes.

Autoimmune muscle diseases (myositis) comprise a group of complex phenotypes influenced by genetic and environmental factors. To identify genetic risk factors in patients of European ancestry, we conducted a genome-wide association study (GWAS) of the major myositis phenotypes in a total of 1710 cases, which included 705 adult dermatomyositis, 473 juvenile dermatomyositis, 532 polymyositis and 202 adult dermatomyositis, juvenile dermatomyositis or polymyositis patients with anti-histidyl-tRNA synthetase (anti-Jo-1) autoantibodies, and compared them with 4724 controls. Single-nucleotide polymorphisms showing strong associations (P<5×10(-8)) in GWAS were identified in the major histocompatibility complex (MHC) region for all myositis phenotypes together, as well as for the four clinical and autoantibody phenotypes studied separately. Imputation and regression analyses found that alleles comprising the human leukocyte antigen (HLA) 8.1 ancestral haplotype (AH8.1) defined essentially all the genetic risk in the phenotypes studied. Although the HLA DRB1*03:01 allele showed slightly stronger associations with adult and juvenile dermatomyositis, and HLA B*08:01 with polymyositis and anti-Jo-1 autoantibody-positive myositis, multiple alleles of AH8.1 were required for the full risk effects. Our findings establish that alleles of the AH8.1 comprise the primary genetic risk factors associated with the major myositis phenotypes in geographically diverse Caucasian populations.

Distribution and severity of weakness among patients with polymyositis, dermatomyositis and juvenile dermatomyositis.

OBJECTIVE: To describe the distribution and severity of muscle weakness using manual muscle testing (MMT) in 172 patients with PM, DM and juvenile DM (JDM). The secondary objectives included characterizing individual muscle group weakness and determining associations of weakness with functional status and myositis characteristics in this large cohort of patients with myositis. METHODS: Strength was assessed for 13 muscle groups using the 10-point MMT and expressed as a total score, subscores based on functional and anatomical regions, and grades for individual muscle groups. Patient characteristics and secondary outcomes, such as clinical course, muscle enzymes, corticosteroid dosage and functional status were evaluated for association with strength using univariate and multivariate analyses. RESULTS: A gradient of proximal weakness was seen, with PM weakest, DM intermediate and JDM strongest among the three myositis clinical groups (P < or = 0.05). Hip flexors, hip extensors, hip abductors, neck flexors and shoulder abductors were the muscle groups with the greatest weakness among all three clinical groups. Muscle groups were affected symmetrically. CONCLUSIONS: Axial and proximal muscle impairment was reflected in the five weakest muscles shared by our cohort of myositis patients. However, differences in the pattern of weakness were observed among all three clinical groups. Our findings suggest a greater severity of proximal weakness in PM in comparison with DM.

The Cutaneous Assessment Tool: development and reliability in juvenile idiopathic inflammatory myopathy.

OBJECTIVES: Clinical care and therapeutic trials in idiopathic inflammatory myopathies (IIM) require accurate and consistent assessment of cutaneous involvement. The Cutaneous Assessment Tool (CAT) was designed to measure skin activity and damage in IIM. We describe the development and inter-rater reliability of the CAT, and the frequency of lesions endorsed in a large population of juvenile IIM patients. METHODS: The CAT includes 10 activity, 4 damage and 7 combined lesions. Thirty-two photographic slides depicting IIM skin lesions were assessed by 11 raters. One hundred and twenty-three children were assessed by 11 paediatric rheumatologists at 10 centres. Inter-rater reliability was assessed using simple agreements and intra-class correlation coefficients (ICC). RESULTS: Simple agreements in recognizing lesions as present or absent were generally high (0.5-1.0). ICCs for CAT lesions were moderate (0.4-0.75) in both slides and real patients. ICCs for the CAT activity and damage scores were 0.71 and 0.81, respectively. CAT activity scores ranged from 0 to 44 (median 7, potential range 0-96) and CAT damage scores ranged from 0 to 13 (median 1, potential range 0-22). The most common cutaneous lesions endorsed were periungual capillary loop changes (63%), Gottron's papules/sign (53%), heliotrope rash (49%) and malar/facial erythema (49%). CONCLUSIONS: Total CAT activity and damage scores have moderate to good reliability. Assessors generally agree on the presence of a variety of cutaneous lesions. The CAT is a promising, semi-quantitative tool to comprehensively assess skin disease activity and damage in IIM.

Muscle metabolites, detected in urine by proton spectroscopy, correlate with disease damage in juvenile idiopathic inflammatory myopathies.

OBJECTIVE: To assess for novel markers of muscle damage using urinary muscle metabolites by 1H magnetic resonance spectroscopy in patients with juvenile idiopathic inflammatory myopathy (IIM). METHODS: Creatine (Cr), choline (Cho), betaine (Bet), glycine (Gly), trimethylamine oxide (TMAO), and several other metabolites were measured in first morning void urine samples from 45 patients with juvenile IIM and from 35 healthy age-matched controls, and correlated with measures of myositis disease activity and damage. Urinary metabolite to age-adjusted creatinine (Cn) ratios were examined. RESULTS: Age-adjusted initial Cr:Cn, Cho:Cn, Bet:Cn, Gly:Cn, and TMAO:Cn ratios were higher in patients with juvenile IIM than controls (P < 0.01). Cr:Cn ratios showed significant correlations with physician-assessed global disease damage (Spearman rs = 0.37; P = 0.01), Steinbrocker functional class (rs = 0.35; P = 0.02), serum Cr (rs = 0.72; P = 0.001), and lactate dehydrogenase (rs = 0.34; P = 0.03) levels. Cho:Cn (rs = 0.3; P = 0.05), Gly:Cn (rs = 0.33; P = 0.03), and TMAO:Cn (rs = 0.36; P = 0.02) ratios showed a significant correlation with serum aldolase levels. Cho:Cn ratios also showed a significant correlation with aspartate aminotransferase levels (rs = 0.35; P = 0.02). A linear regression model was used to evaluate the factors influencing urinary Cr:Cn ratios in the 43 patients with data sets available at the initial visit. The regression model explained 73% of the variation in Cr:Cn ratios. The most significant factor was the physician-assessed global disease damage (R2 = 0.50, P = 0.015). CONCLUSION: Urinary Cr:Cn, Cho:Cn, Bet:Cn, Gly:Cn, and TMAO:Cn ratios are elevated in juvenile IIM and Cr:Cn correlates strongly with global disease damage. The Cr:Cn ratio may have potential utility as a marker of myositis disease damage.

Proposed preliminary core set measures for disease outcome assessment in adult and juvenile idiopathic inflammatory myopathies.

In order to develop a preliminary core set of disease outcome measures for use in clinical trials of idiopathic inflammatory myopathies (IIM), we evaluated those measures used in previous trials, assessed the validation of published instruments and discussed these at an international consensus conference. The initial proposals were further refined by a multidisciplinary group of adult and paediatric specialists experienced in IIM using the Delphi method. The proposed preliminary core set of disease activity measures consists of five domains: physician and patient/parent global assessments of disease activity; muscle strength; physical function; serum activity of muscle enzymes; and an assessment tool to capture extra-skeletal muscle disease activity. The group recommended further development of a core set of disease damage measures for assessment of persistent changes in anatomy, pathology and function of at least 6 months' duration. The group recommended that patient-reported outcomes should include generic health-related quality of life assessments using the Medical Outcomes Study 36-item Short Form (SF-36) health survey in adult IIM patients and a validated quality of life instrument for paediatric patients. We propose the core set of outcome measures as a minimum group of assessments to include in all IIM therapeutic studies. The use of this core set should assist in standardizing outcome measurement and in optimizing therapeutic trials in myositis.

Persistent maternally derived peripheral microchimerism is associated with the juvenile idiopathic inflammatory myopathies.

OBJECTIVE: Fetal cells have been demonstrated in the active lesions of adult women with systemic sclerosis. Because the juvenile idiopathic inflammatory myopathies (JIIM) share clinical and histopathological features with systemic sclerosis and graft-vs-host disease, we explored the possibility that maternal cells persist and play a role in the pathogenesis of JIIM. METHODS: DNA samples extracted from peripheral blood of 28 JIIM patients (14 females, 14 males) and 23 healthy controls were assessed for microchimerism by the HLA Cw polymerase chain reaction method. HLA Cw alleles from eight mothers and three healthy siblings of JIIM patients were also examined. RESULTS: A microchimeric allele was identified in 19 of 26 JIIM patients whose data were able to be interpreted, compared with two of 21 healthy controls (P<0.001). Subjects with microchimerism ranged in age from 4 to 28 yr. In eight cases in which maternal peripheral blood was available, the additional Cw allele present in the patients was confirmed to be identical to a maternal allele. Three healthy siblings of JIIM patients did not have evidence of a microchimeric Cw allele. CONCLUSION: Maternal cells can persist in the peripheral blood of their children up to three decades after birth, and are found in a higher proportion in JIIM patients compared with controls. These findings, with other data, suggest that maternal cells may be involved in the immunopathogenesis of JIIM.

Autologous stem cell transplantation for pediatric rheumatic diseases.

The National Institute of Allergy and Infectious Disease, National Institutes of Health, convened a workshop entitled The Next Step: Protocol Development for Autologous Stem Cell Transplantation for Pediatric Rheumatic Disease, June 2000, co-chaired by Drs. Karyl Barron and Carol Wallace. The goal of the workshop was to focus on the scientific rationale for stem cell transplantation therapy in the pediatric diseases, unique aspects of this therapy in the pediatric rheumatic diseases, transplantation issues and options, regulatory issues, and development of a DNA repository for these diseases.

Juvenile dermatomyositis presenting with anasarca: A possible indicator of severe disease activity.

Juvenile dermatomyositis is a rare autoimmune disease characterized by inflammation of the muscle, skin, and other organs. Although localized edema is a common feature of juvenile dermatomyositis, generalized edema has been reported infrequently. We describe a patient with juvenile dermatomyositis presenting with anasarca and note that generalized edema has been associated with severe disease activity.

Validation of the Childhood Health Assessment Questionnaire in the juvenile idiopathic myopathies. Juvenile Dermatomyositis Disease Activity Collaborative Study Group.

OBJECTIVE: To examine the validity of the Childhood Health Assessment Questionnaire (CHAQ) in patients with juvenile idiopathic inflammatory myopathy (IIM). METHODS: One hundred fifteen patients were enrolled in a multicenter collaborative study, during which subjects were assessed twice, 7-9 months apart. Physical function was measured using the CHAQ. Internal reliability was assessed using adjusted item-total correlations and item endorsement rates. Construct validity was assessed by comparing predicted and actual correlations of the CHAQ with other measures of physical function and disease activity. Responsiveness was assessed by calculating effect size (ES) and standardized response mean (SRM) in a group of a priori defined "improvers." RESULTS: Item-total correlations were high (rs range = 0.35-0.81), suggesting all items were related to overall physical function. Manual muscle testing and the Childhood Myositis Assessment Scale correlated moderate to strongly with the CHAQ (r = -0.64 and -0.75, both p < 0.001). Moderate correlations were also seen with the physician global assessment of disease activity (rs = 0.58, p < 0.001), parent global assessment of overall health (rs = -0.65, p < 0.001), Steinbrocker function class (rs = 0.69, p < 0.001), and global skin activity (rs = 0.40, p < 0.001), while global disease damage and skin damage had low correlations (rs = 0.13 and 0.07, p > or =0.17). Responsiveness of the CHAQ was high, with ES = 1.05 and SRM = 1.20. CONCLUSION: In this large cohort of patients with juvenile IIM, the CHAQ exhibited internal reliability, construct validity, and strong responsiveness. We conclude that the CHAQ is a valid measure of physical function in juvenile IIM, appropriate for use in therapeutic trials, and potentially in the clinical care of these patients.

Update on the genetics of the idiopathic inflammatory myopathies.

A number of lines of investigation suggest that, as is likely the case for other autoimmune diseases, the idiopathic inflammatory myopathies (IIM) develop as a result of specific environmental exposures in genetically susceptible individuals. Current data imply that multiple genes are involved in the etiology of these complex disorders. Targeted gene studies and whole genome approaches have begun to identify several genetic risk factors for autoimmune diseases, but the rarity and heterogeneity of the IIM have limited our knowledge of their associated genes. Current findings suggest that human leukocyte antigen (HLA) genes on chromosome 6, particularly HLA DRB1*0301 and the linked allele DQA1*0501, have the strongest associations with all clinical forms of IIM in white patients. Different HLA alleles, however, may confer risk or protection for myositis in distinct ethnic, serologic, and environmental exposure groups. Non-HLA genetic risk factors, which have been documented for other autoimmune diseases, are now being identified for the IIM. These include polymorphic genes encoding immunoglobulin heavy chains (defined by serologic markers known as Gm allotypes), cytokines and their receptors, and certain proteins that accumulate in the myocyte vacuoles of inclusion body myositis patients. Selected allelic polymorphisms of interleukin-1 receptor antagonist variable number tandem repeats and genes for tumor necrosis factor alpha and interleukin-1 alpha also have recently been associated with IIM. The pathogenic bases for the differences among the many clinically, pathologically and immunologically defined syndromes known as the IIM will be elucidated through a better understanding of the multiple genes that define risks for their development, as well as through investigations of gene-gene and gene-environment interactions.

Postlicensure safety surveillance for varicella vaccine.

CONTEXT: Since its licensure in 1995, the extensive use of varicella vaccine and close surveillance of the associated anecdotal reports of suspected adverse effects provide the opportunity to detect potential risks not observed before licensure because of the relatively small sample size and other limitations of clinical trials. OBJECTIVES: To detect potential hazards, including rare events, associated with varicella vaccine, and to assess case reports for clinical and epidemiological implications. DESIGN AND SETTING: Postlicensure case-series study of suspected vaccine adverse events reported to the US Vaccine Adverse Event Reporting System (VAERS) from March 17, 1995, through July 25, 1998. MAIN OUTCOME MEASURES: Numbers of reported adverse events, proportions, and reporting rates (reports per 100,000 doses distributed). RESULTS: VAERS received 6574 case reports of adverse events in recipients of varicella vaccine, a rate of 67.5 reports per 100,000 doses sold. Approximately 4% of reports described serious adverse events, including 14 deaths. The most frequently reported adverse events were rashes, possible vaccine failures, and injection site reactions. Misinterpretation of varicella serology after vaccination appeared to account for 17% of reports of possible vaccine failures. Among 251 patients with herpes zoster, 14 had the vaccine strain of varicella zoster virus (VZV), while 12 had the wild-type virus. None of 30 anaphylaxis cases was fatal. An immunodeficient patient with pneumonia had the vaccine strain of VZV in a lung biopsy. Pregnant women occasionally received varicella vaccine through confusion with varicella zoster immunoglobulin. Although the role of varicella vaccine remained unproven in most serious adverse event reports, there were a few positive rechallenge reports and consistency of many cases with syndromes recognized as complications of natural varicella. CONCLUSION: Most of the reported adverse events associated with varicella vaccine are minor, and serious risks appear to be rare. We could not confirm a vaccine etiology for most of the reported serious events; several will require further study to clarify whether varicella vaccine plays a role. Education is needed to ensure appropriate use of varicella serologic assays and to eliminate confusion between varicella vaccine and varicella zoster immunoglobulin. JAMA. 2000;284:1271-1279

Magnetic resonance imaging detection of occult skin and subcutaneous abnormalities in juvenile dermatomyositis. Implications for diagnosis and therapy.

OBJECTIVE: To assess the utility of magnetic resonance imaging (MRI) of skin, subcutaneous tissue, and fascia in evaluating disease activity in juvenile dermatomyositis (DM). METHODS: Short tau inversion recovery (STIR) MRI of the proximal thighs and buttocks, cutaneous assessment, and other measures of disease activity were prospectively obtained in 26 children meeting criteria for probable or definite juvenile DM. Also undergoing STIR MRI assessment were 8 subjects who were being evaluated for muscle disorders and who were not diagnosed as having juvenile DM. RESULTS: Skin, subcutaneous, or fascial edema of the thighs and buttocks were seen on STIR MRI in up to 85% of juvenile DM patients at baseline evaluation compared with no more than 38% of the comparison group without juvenile DM. In juvenile DM, STIR MRI skin and subcutaneous edema scores correlated (r(s) = 0.51, P = 0.008), as did fascial and muscle edema scores (r(s) = 0.58, P = 0.002). Skin global disease activity scores correlated with MRI skin edema scores (r(s) = 0.41, P = 0.04), and serum aldolase levels correlated with both MRI skin and subcutaneous edema scores (r = 0.44 and 0.40, P = 0.03 and 0.05 respectively). The extent and severity of STIR MRI changes in the skin, subcutaneous tissue, and fascia were not predicted by most other measures of juvenile DM disease activity. Five juvenile DM patients with thigh MRI subcutaneous edema developed clinically apparent calcinosis at the same location within 9 months. CONCLUSION: Edema or inflammation in the skin, subcutaneous tissue, and fascia, found on STIR MRI, is common in juvenile DM patients and is often undetected by standard assessments. These MRI changes can precede the development of calcinosis. STIR MRI may be a useful adjunct for assessing disease activity and guiding the treatment of juvenile DM.

Polymorphisms in the IL-1 receptor antagonist gene VNTR are possible risk factors for juvenile idiopathic inflammatory myopathies.

Although HLA-DRB1 and -DQA1 alleles have been associated with adult and juvenile idiopathic inflammatory myopathies (JIIM), they only partially account for the genetic risk for these autoimmune disorders. Because IL-1alpha and IL-1beta, and the anti-inflammatory competitive inhibitor, IL-1 receptor antagonist (IL-1Ra), have been implicated in the pathogenesis of myositis, we assessed the role of variable number tandem repeat (VNTR) polymorphisms of the IL-1Ra gene (IL-1RN) in the aetiology of JIIM: IL-1RN VNTR polymorphisms were performed on 250 JIIM patients and 471 race-matched controls and were correlated with clinical characteristics. The IL-1RN A1 allele, associated with increased proinflammatory activity, was found to be a risk factor for Caucasians with JIIM (96.0% carriage rate versus 90.2% in race-matched controls, Pcorr = 0.037, odds ratio (OR) = 2.5, confidence interval (CI) = 1.1-5.8), but not for African-Americans, in whom the A3 allele was a possible risk factor (7.0% versus 1.1% in race-matched controls, Pcorr = 0.07, OR = 6.5, CI = 1.1-40.3). IL-1RN genotypes did not correlate with circulating levels of IL-1Ra, which were higher in patients than in controls. The polymorphic IL-1RN locus could be the first non-MHC genetic risk factor identified for JIIM, and different alleles may confer susceptibility for different ethnic groups.

Idiopathic inflammatory muscle disease: clinical aspects.

Although much remains to be learned about the immune-mediated myositis syndromes, information generated from recent studies in a number of areas may assist physicians in patient management. Topics reviewed here include: data supporting the association of myositis with cancer and the appropriate evaluations for malignancy in a myositis patient; an approach to the assessment of patients with dermatomyositis sine myositis; the usefulness of the clinicopathological and serological classifications; a discussion of whether childhood and adult myositis are the same or different entities; a review of those prognostic factors to consider in the clinical management of myositis patients; current approaches and their limitations for assessing disease activity and damage. To improve our limited understanding of the myositis syndromes, national and international collaborations are needed to obtain the necessary numbers of subjects, given the rarity and heterogeneity of these disorders.

Chimeric cells of maternal origin in juvenile idiopathic inflammatory myopathies. Childhood Myositis Heterogeneity Collaborative Group.

We identified maternal microchimerism by fluorescence in-situ hybridisation in magnetically-separated CD4 or CD8 peripheral blood cells of eight of nine male patients with juvenile idiopathic inflammatory myopathy, compared with two of nine healthy male controls. We also found maternal microchimerism in inflammatory lesions (one skin sample and nine muscle biopsy samples) of all ten patients examined, compared with two of ten biopsy samples from patients with other muscle disorders. These results suggest that maternal cells may be involved in the pathogenesis of juvenile idiopathic inflammatory myopathy.

Development of validated disease activity and damage indices for the juvenile idiopathic inflammatory myopathies. II. The Childhood Myositis Assessment Scale (CMAS): a quantitative tool for the evaluation of muscle function. The Juvenile Dermatomyositis Disease Activity Collaborative Study Group.

OBJECTIVE: To develop, validate, and determine the measurement characteristics of a quantitative tool for assessing the severity of muscle involvement in children with idiopathic inflammatory myopathies. METHODS: The Childhood Myositis Assessment Scale (CMAS) was developed from 2 existing observational functional assessment tools to assess muscle function in the areas of strength and endurance across a wide range of ability and ages. The 14 ordinal items included were chosen to assess primarily axial and proximal muscle groups and are ranked with standard performance and scoring methods. Following the development of the CMAS, a training video and written instructions were developed and reviewed by the physicians participating in this study. Subsequently, utilizing a randomized block design, 12 physicians independently scored 10 children (9 with dermatomyositis, 1 with polymyositis; ages 4-15 years) twice in one day (morning and afternoon) on the CMAS. A pediatric physical therapist performed quantitative manual muscle strength testing (MMT) twice on each child (morning and afternoon), including the neck, trunk, and proximal and distal extremity muscle groups. RESULTS: The CMAS has a potential range of 0-51, with higher scores indicating greater muscle strength and endurance. The observed mean for the 10 patients was 36.4 (median 44, SD 14.1, observed range 5-51). The total score for the CMAS correlated with the physician's global assessment (by visual analog scale) of disease activity, the MMT score, serum creatine kinase level, and the Juvenile Arthritis Functional Assessment Report score. The score on the CMAS was not correlated with patient age. Interrater reliability (Kendall's coefficient of concordance) ranged from 0.77 to 1.0 for individual items (all P < 0.001), and overall, it was 0.95 (P < 0.001). Intrarater reliability for the individual physicians was measured by correlation of the CMAS scores for each patient on 2 separate evaluations and ranged from 0.97 to 0.99, with an overall correlation for all physicians of 0.98 (all P < 0.001). CONCLUSION: The CMAS demonstrated an acceptable range of observed scores, excellent convergent validity, and excellent inter- and intrarater reliability. The CMAS is validated to quantitatively assess muscle function in the areas of strength and endurance in children with idiopathic inflammatory myopathies. It can be used in routine clinical care as well as therapeutic trials.

Novel gastrointestinal tract manifestations in juvenile dermatomyositis.

We report a case of juvenile dermatomyositis in which a dilated atonic esophagus was associated with delayed gastric emptying and intestinal mucosal thickening, resulting in a radiographic "stacked coin" appearance. These findings, which can also occur in infectious, neoplastic, or other immune-mediated diseases, broaden the spectrum of gastrointestinal tract manifestations in juvenile dermatomyositis. Physicians should be alert for these treatable manifestations in children with myositis who present with unexplained gastrointestinal symptoms, which are reversible with immunosuppressive therapy.