Abstract | OBJECTIVE:
Calcinosis is a major cause of morbidity in JDM and has previously been linked to anti-NXP2 autoantibodies, younger age at disease onset and more persistent disease activity. This study aimed to investigate the clinical associations of anti-NXP2 autoantibodies in patients with JDM stratified by age at disease onset. METHODS: A total of 285 patients with samples and clinical data were recruited via the UK Juvenile Dermatomyositis Cohort and Biomarker Study. The presence of anti-NXP2 was determined by both immunoprecipitation and ELISA. Logistic regression analysis was performed to assess the age-dependent relationship between anti-NXP2 and the development of calcinosis and disease activity measures. RESULTS: We identified anti-NXP2 autoantibodies in 56 patients (20%). While in all patients younger age at disease onset was associated with an increased risk of calcinosis and this relationship was nearly linear, anti-NXP2 autoantibodies substantially increased the risk of calcinosis across all ages (P = 0.025) and were detectable prior to calcinosis development. Children with anti-NXP2 autoantibodies had a greater degree of weakness (median lowest ever Childhood Myositis Assessment Score 29.6 vs 42) and were less likely to be in remission at 2 years post-diagnosis. No difference in disease activity was seen 4 years post-diagnosis. CONCLUSION: Children diagnosed at a young age have a high risk of calcinosis regardless of autoantibody status. However, the presence of anti-NXP2 autoantibodies substantially increases the risk of calcinosis across all ages and is associated with disease severity.
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Authors | Sarah L Tansley, Zoe E Betteridge, Gavin Shaddick, Harsha Gunawardena, Katie Arnold, Lucy R Wedderburn, Neil J McHugh, Juvenile Dermatomyositis Research Group |
Journal | Rheumatology (Oxford, England)
(Rheumatology (Oxford))
Vol. 53
Issue 12
Pg. 2204-8
(Dec 2014)
ISSN: 1462-0332 [Electronic] England |
PMID | 24987158
(Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)
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Copyright | © The Author 2014. Published by Oxford University Press on behalf of the British Society for Rheumatology. |
Chemical References |
- Autoantibodies
- Biomarkers
- DNA-Binding Proteins
- Adenosine Triphosphatases
- MORC3 protein, human
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Topics |
- Adenosine Triphosphatases
(immunology)
- Age of Onset
- Autoantibodies
(blood)
- Biomarkers
(blood)
- Calcinosis
(etiology, immunology)
- Child
- Child, Preschool
- Cohort Studies
- DNA-Binding Proteins
(immunology)
- Dermatomyositis
(complications, immunology)
- Female
- Humans
- Male
- Muscle Weakness
(etiology, immunology)
- Prognosis
- Risk Assessment
(methods)
- Severity of Illness Index
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