Association of Diagnostic Criteria and Autoantibodies with Juvenile Dermatomyositis in Newly Diagnosed Children

Shin, Kyung Sue; Kim, Joong Gon

Abstract

PURPOSE
To determine the clinical association of diagnostic criteria and the prevalence of autoantibodies in newly diagnosed children with juvenile dermatomyositis(JDM).
METHODS
Thirty-two children with JDM were identified at Seoul National University Children's Hospital from March 1985 to March 1999 by retrospective review. The diagnosis of JDM was based of the criteria proposed by Bohan and Peter. We investigated for the presence of several autoanti bodies: antinuclear(ANA), double-stranded DNA, anti-Sm, anti-ribonucleoprotein(RNP), anti-SSA/ SSB, anti-Jo1, anti-Scl-70 antibodies and rheumatoid factor(RF).
RESULTS
Sex ratio and age at diagnosis were similar to data published in other studies. All the newly diagnosed children with JDM had a typical rash(100%) and proximal muscle weakness(100%); 17(53%) had muscle pain or tenderness; 10(31%) calcinosis; eight(25%) dysphagia; eight(25%) arthritis, and seven(22%) fever. Muscle enzymes were elevated in 90% of the patients. Of the 27 patients who had an electromyogram, 20(70%) had diagnostic results. Sixteen(70%) of biopsied patients had appropriated results for JDM. Patients were negative for all autoantibodies except ANA and RF. ANA and RF were detected in 47% and 7% of the patients respectively.
CONCLUSION
Although the sensitivity of the criteria proposed by Bohan and Peter is superior, each of these criteria has possible confounding factors. Additional criteria may be needed for early diagnosis of JDM. Based on our findings of autoantibodies in JDM, we do not recommend routine testing for autoantibodies in children with typical JDM.