- Oral presentation
- Open Access
8.4 Novel autoantibodies targeting a p140 protein are a major autoantigen system in juvenile dermatomyositis and a marker of calcinosis
© Gunawardena et al; licensee BioMed Central Ltd. 2008
- Published: 15 September 2008
- P140 Protein
- Female Ratio
- Negative Case
- Nuclear Matrix
To demonstrate that autoantibodies targeting a p140 protein are a major autoantigen in juvenile dermatomyositis (JDM) and describe the clinical associations in children recruited to the JDM Registry (JDRR).
21% of children were positive for anti-p140 on IPP, with a weak non-specific nuclear pattern or negative ANA on IF. No anti-p140 cases were positive for other autoantibody specificities. Immunodepletion confirmed that p140 and p155/140 are different autoantigens. Anti-p140 positives compared to negatives had a similar male:female ratio and age at diagnosis. No significant difference was observed in the type or distribution of rash when comparing anti-p140 positives vs. negatives except for more rash on the trunk in negative cases (p = 0.017). Calcinosis was significantly more frequent in anti-p140 positives (52%) compared to negatives (13%) (p < 0.001, OR 7.1 95% CI 3–16.8). When comparing anti-p140 and anti-p155/140 cases; cutaneous oedema (p = 0.04) and rash over the trunk (p = 0.002) and small joints (p = 0.013) was more frequent in anti-p155/140. Calcinosis in anti-p140 remained a significant feature compared to anti-p155/140 (p = 0.005, OR 6.4 95% CI 2–22).
Anti-p140 found in this cohort is likely to be the same as anti-MJ, described against nuclear matrix protein NXP-2 ; further confirmation is required. Anti-p140 is a major autoantibody subset in JDM. Further characterisation of this system will provide insights into the pathophysiology of calcinosis in JDM.
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This article is published under license to BioMed Central Ltd.