Muscle ischaemia associated with NXP2 autoantibodies: a severe subtype of juvenile dermatomyositis.

Abstract

Objectives:

Myositis-specific autoantibodies (MSAs) are increasingly used to delineate distinct subgroups of JDM. The aim of our study was to explore without a priori hypotheses whether MSAs are associated with distinct clinical-pathological changes and severity in a monocentric JDM cohort.

Methods:

Clinical, biological and histological findings from 23 JDM patients were assessed. Twenty-six histopathological parameters were subjected to multivariate analysis.

Results:

Autoantibodies included anti-NXP2 (9/23), anti-TIF1γ (4/23), anti-MDA5 (2/23), no MSAs (8/23). Multivariate analysis yielded two histopathological clusters. Cluster 1 (n = 11) showed a more severe and ischaemic pattern than cluster 2 (n = 12) assessed by: total score severity ⩾ 20 (100.0% vs 25.0%); visual analogic score ⩾6 (100.0% vs 25.0%); the vascular domain score >1 (100.0% vs 41.7%); microinfarcts (100% vs 58.3%); ischaemic myofibrillary loss (focal punched-out vacuoles) (90.9 vs 25%); and obvious capillary loss (81.8% vs 16.7). Compared with cluster 2, patients in cluster 1 had strikingly more often anti-NXP2 antibodies (7/11 vs 2/12), more pronounced muscle weakness, more gastrointestinal involvement and required more aggressive treatment. Furthermore, patients with anti-NXP2 antibodies, mostly assigned in the first cluster, also displayed more severe muscular disease, requiring more aggressive treatment and having a lower remission rate during the follow-up period.

Conclusion:

Marked muscle ischaemic involvement and the presence of anti-NXP2 autoantibodies are associated with more severe forms of JDM.

• Authors: Jessie Aouizerate, Marie De Antonio, Brigitte Bader-Meunier, Christine Barnerias, Christine Bodemer, Arnaud Isapof, Pierre Quartier, Isabelle Melki, Jean-Luc Charuel, Guillaume Bassez, Isabelle Desguerre, Romain K Gherardi, François-Jérôme Authier, Cyril Gitiaux
• Journal: Rheumatology (Oxford, England) (Rheumatology (Oxford)) Vol. 57 Issue 5 Pg. 873-879 (05 01 2018) ISSN: 1462-0332 [Electronic] England
• PMID: 29474663 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Autoantibodies
• Biomarkers
• DNA-Binding Proteins
• Adenosine Triphosphatases
• MORC3 protein, human

Topics

• Adenosine Triphosphatases (immunology, metabolism)
• Autoantibodies (immunology)
• Biomarkers (metabolism)
• Biopsy
• DNA-Binding Proteins (immunology, metabolism)
• Dermatomyositis (complications, immunology, metabolism)
• Disease Progression
• Female
• Follow-Up Studies
• Humans
• Ischemia (diagnosis, etiology, immunology)
• Male
• Muscle, Skeletal (blood supply, diagnostic imaging)
• Severity of Illness Index