[Myositis-specific antibodies associated with juvenile dermatomyositis]

Abstract

Background: Juvenile dermatomyositis (JDM) is a rare autoimmune disease associated with typical skin changes and muscle weakness. Within the framework of the diagnostics, myositis-associated (MAA) and myositis-specific antibodies (MSA) can be detected. These are important for the assessment of the course of the disease and the prognosis.

Method: In this study we searched for MAA and MSA by means of a line immunoassay in 12 currently supervised JDM patients in the Rheumatism Center Sankt Augustin.

Results: In 10 of the 12 patients a total of 15 myositis antibodies were detected where 3 patients each had Mi2, SRP or NXP2 antibodies, 2 had TIF-1γ antibodies and Jo1 or Mi2β antibodies were found in 1 patient each. Of the patients two had additional PM-Scl antibodies. In the 10 patients with detected antibodies, a good phenotype-serotype correlation was found with deviation from the phenotypes described in the literature in only 3 patients.

Conclusion: The frequent detection of certain antibodies and the good correlation with those phenotypes described in the literature, show that the determination of MSA is an important diagnostic tool to assess the course, complications and outcome and to initiate adequate therapy at an early stage.

Keywords: Juvenile dermatomyositis; Myositis-associated antibodies; Myositis-specific antibodies; Phenotype serotype correlation.