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.

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.

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.

Lyme arthritis in children: clinical epidemiology and long-term outcomes

OBJECTIVE

Although Lyme disease has become a relatively common cause of arthritis among children in areas of the country in which the disease is endemic, little information is available about the clinical epidemiology and long-term outcomes of children with Lyme arthritis. We conducted a long-term follow-up study to determine the clinical epidemiology of Lyme arthritis in children as well as their long-term outcomes.

PATIENTS AND METHODS

All children seen between 1982 and 1991 at the Pediatric Rheumatology Clinic at Newington Children's Hospital (Newington, CT) with an initial diagnosis of Lyme disease were identified. Medical records were reviewed and structured telephone interviews were conducted to obtain demographic, clinical, and follow-up data.

RESULTS

A total of 90 children (63% boys) with a mean age of 8.3 years (range, 1.8-16 years) at the time of diagnosis of Lyme arthritis were evaluated. Lyme arthritis was preceded by early Lyme disease in 23 (26%) of the children; however, only 8 (35%) of these children had been treated with appropriate antimicrobial therapy at that early stage. Ninety percent of the children had arthritis of at least one knee, while small joints were rarely involved. For the 31 children who underwent arthrocentesis, the mean white blood cell count in the synovial fluid was 38 000 cells/mm3 (range, 7000-99 000 cells/mm3) with predominantly neutrophils. For the 79 children for whom an erythrocyte sedimentation rate was determined, the highest level for 61 (77%) was >20 mm/h and for 36 (46%) was >50 mm/h. Antimicrobial therapy was initiated 2 days to 5.5 years (median, 2 months) after the onset of symptoms. However, 5 of the children were never treated with antimicrobials. Fifty-one percent of the patients had a single episode of arthritis, while 49% reported recurrent episodes of arthritis over a period of 1 week to 8 years (median, 6 months). Two children (2%) developed chronic arthritis and underwent arthroscopic synovectomy. At the time of the telephone follow-up evaluation, performed 2 to 12 years (median, 7 years) after the onset of the Lyme arthritis, 4 children had ongoing musculoskeletal complaints that resulted in mild to moderate impairment of school or sports activities, but none of the children had evidence of active arthritis.

CONCLUSION

The results of this investigation suggest that the prognosis for children with Lyme arthritis who are treated with appropriate antimicrobial therapy is excellent.

Development of validated disease activity and damage indices for the juvenile idiopathic inflammatory myopathies: I. Physician, parent, and patient global assessments. Juvenile Dermatomyositis Disease Activity Collaborative Study Group

OBJECTIVE

To determine the reliability, content validity, and responsiveness of physician global assessments of disease activity and damage in the juvenile idiopathic inflammatory myopathies (IIM), and to investigate concordance among physician, parent, and patient global ratings.

METHODS

Sixteen pediatric rheumatologists rated 10 juvenile IIM paper patient cases for global disease activity and damage, and assessed the importance of 51 clinical and laboratory parameters in formulating their global assessments. Then, 117 juvenile IIM patients were enrolled in a protocol to examine the relationship between Likert and visual analog scale global assessments, their sensitivity to change, and the comparability of physician, parent, and patient global ratings.

RESULTS

Pediatric rheumatologists demonstrated excellent interrater reliability in their global assessments of juvenile IIM disease activity and damage (97.7% and 94.7% agreement among raters, respectively), and agreed on a core set of clinical parameters in formulating their judgments. Likert scale ratings correlated with those on a visual analog scale, and both were comparable in responsiveness (standardized response means -0.56 for disease activity, 0.02 [Likert] and 0.14 [visual analog] for damage, measured over 8 months). Parent global ratings of disease activity correlated with physician assessments, but were not colinear (Spearman's correlation [r] = 0.41-0.45). Patient global disease activity assessments correlated with those done by parents (r = 0.57-0.84) and physicians (r = 0.37-0.63), but demonstrated less responsiveness (standardized response means -0.21 and -0.12, respectively, over 8 months).

CONCLUSION

Physician global assessments of juvenile IIM disease activity and damage demonstrated high interrater reliability and were shown to be comprehensive measures. Both physician and parent disease activity assessments should be considered valuable as quantitative measures for evaluating therapeutic responses in juvenile IIM patients.

Interpretation of immunoblot in pediatric Lyme arthritis

OBJECTIVE

To determine the pattern of bands present on an immunoblot (Western blot) in children with Lyme arthritis.

METHODS

Sera from 20 children with Lyme arthritis from an endemic area were assayed, and the results compared with those obtained in 162 control sera from the same area. The study was retrospective, serum bank based.

RESULTS

Eighty-seven percent of control sera revealed no bands on immunoblot, and all had < or = 4 bands. All Lyme arthritis sera revealed > or = 5 bands (mean 8.4, range 5-13 bands). Bands of molecular weight 25, 28, 39, 47, 50, and 93 kDa were seen in patients and not in controls. There was no correlation between duration of arthritis or activity of arthritis at presentation and number of bands present.

CONCLUSION

Criteria were derived for a positive immunoblot based on the number and molecular weights of bands seen in our laboratory. These are the presence of 5 or more bands, of which at least one is an apparently specific band (25, 28, 39, 47, 50, or 93 kDa). Results of immunoblot are useful to confirm clinically suspected Lyme arthritis.

Intravenous immunoglobulin in the treatment of systemic juvenile rheumatoid arthritis: a randomized placebo controlled trial. Pediatric Rheumatology Collaborative Study Group

OBJECTIVE

To assess the efficacy and safety of intravenous immunoglobulin (IVIG) in juvenile rheumatoid arthritis (JRA).

METHODS

Thirty-one children with active, refractory, systemic JRA were randomized into a multicentered, double blinded, placebo controlled trial. Patients received infusions of 1.5 g/kg of IVIG or placebo (0.1% albumin) every 2 weeks for 2 months, then monthly for 4 months (total: up to 9 infusions over 6 months). Twenty-nine of the 31 patients were included in the efficacy subset.

RESULTS

Fourteen patients discontinued prematurely from study, 7 in each treatment group. A higher proportion of patients in the IVIG group improved (50 vs 27%) as assessed by the physician's global assessment. However, the sample size was small and this difference was not statistically significant. IVIG was not more effective than placebo in reducing the number of days with fever or other systemic manifestations. Changes from baseline in the joint count, hemoglobin, albumin, platelet count, and erythrocyte sedimentation rate did not differ between treatment groups.

CONCLUSION

Our results suggest that high dose IVIG has limited clinical utility in systemic JRA. However, this trial failed to enroll adequate numbers of patients to permit valid statistical intergroup comparisons, and the results must be considered nondefinitive.

Methotrexate in resistant juvenile rheumatoid arthritis. Results of the U.S.A.-U.S.S.R. double-blind, placebo-controlled trial. The Pediatric Rheumatology Collaborative Study Group and The Cooperative Children's Study Group

BACKGROUND

The antimetabolite methotrexate has been shown in placebo-controlled trials to be effective in adults with rheumatoid arthritis. Methotrexate may also be effective in children with resistant juvenile rheumatoid arthritis, but the supporting data are from uncontrolled trials.

METHODS

Centers in the United States and the Soviet Union participated in this randomized, controlled, double-blind trial designed to evaluate the effectiveness and safety of orally administered methotrexate. Patients received one of the following treatments each week for six months: 10 mg of methotrexate per square meter of body-surface area (low dose), 5 mg of methotrexate per square meter (very low dose), or placebo. The use of prednisone (less than or equal to 10 mg per day) and two nonsteroidal antiinflammatory drugs was also allowed.

RESULTS

The 127 children (mean age, 10.1 years) had a mean duration of disease of 5.1 years; 114 qualified for the analysis of efficacy. According to a composite index of several response variables, 63 percent of the children who received low-dose methotrexate improved, as compared with 32 percent of those in the very-low-dose group and 36 percent of those in the placebo group (P = 0.013). As compared with the placebo group, the low-dose group also had significantly larger mean reductions from base line in the number of joints with pain on motion (-11.0 vs. -7.1), the pain-severity score (-19 vs. -11.5), the number of joints with limited motion (-5.4 vs. -0.7), and the erythrocyte sedimentation rate (-19.0 vs. -6 mm per hour). In the methotrexate groups only three children had the drug discontinued because of mild-to-moderate side effects; none had severe toxicity.

CONCLUSIONS

Methotrexate given weekly in low doses is an effective treatment for children with resistant juvenile rheumatoid arthritis, and at least in the short term this regimen is safe.

Auranofin therapy for juvenile rheumatoid arthritis: results of the five-year open label extension trial

Eighty-eight children with juvenile rheumatoid arthritis (JRA) who completed a double blind, randomized placebo controlled trial of oral gold were entered into an open label extension phase during which they received auranofin (AF) at a dosage of 0.15-0.2 mg/kg/day (9 mg/day maximum). Eleven (12.5%) patients completed 5 years of AF therapy; 77 (87.5%) did not. Fifteen (17%) of the 88 were in disease remission at the final visit. Mean duration of therapy for those who discontinued was 646 days. Parental/patient decision and insufficient therapeutic effect were the 2 most frequent reasons for early termination, followed by adverse effects. Though relatively well tolerated, AF provides adequate longterm management for only a small percentage of patients with JRA.