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.
- juvenile dermatomyositis
- Department of Pharmacy & Pharmacology - Head of Department
- EPSRC Centre for Doctoral Training in Statistical Applied Mathematics (SAMBa)
- Centre for Therapeutic Innovation
Person: Research & Teaching