Anti-Jo-1 antibody levels correlate with disease activity in idiopathic inflammatory myopathy.

Abstract

OBJECTIVE:

Previous case series have examined the relationship between anti-Jo-1 antibody levels and myositis disease activity, demonstrating equivocal results. Using enzyme-linked immunosorbent assays (ELISAs) and novel measures of myositis disease activity, the current study was undertaken to systematically reexamine the association between anti-Jo-1 antibody levels and various disease manifestations of myositis.

METHODS:

Serum anti-Jo-1 antibody levels were quantified using 2 independent ELISA methods, while disease activity was retrospectively graded using the Myositis Disease Activity Assessment Tool, which measures disease activity in 7 different organ systems via the Myositis Disease Activity Assessment Visual Analog Scale (VAS) and the Myositis Intention-to-Treat Index (MITAX) components. Spearman's rank correlation coefficients and mixed linear regression analysis were used to identify associations between anti-Jo-1 antibody levels and organ-specific disease activity in cross-sectional and longitudinal analyses, respectively.

RESULTS:

Cross-sectional assessment of 81 patients with anti-Jo-1 antibody revealed a modest correlation between the anti-Jo-1 antibody level and the serum creatine kinase (CK) level, as well as muscle and joint disease activity. Correlation coefficients were similar for CK levels (r(s) = 0.38, P = 0.002), myositis VAS (r(s) = 0.36, P = 0.002), and arthritis VAS (r(s) = 0.40, P = 0.001). In multiple regression analyses of 11 patients with serial samples, anti-Jo-1 antibody levels correlated significantly with CK levels (R(2) = 0.65, P = 0.0002), myositis VAS (R(2) = 0.53, P = 0.0008), arthritis VAS (R(2) = 0.53, P = 0.006), pulmonary VAS (R(2) = 0.69, P = 0.005), global VAS (R(2) = 0.63, P = 0.002), and global MITAX (R(2) = 0.64, P = 0.0003).

CONCLUSION:

In this large series of patients with idiopathic inflammatory myopathy, anti-Jo-1 antibody levels correlated modestly with muscle and joint disease, an association confirmed by a custom ELISA using recombinant human Jo-1. More striking associations emerged in a smaller longitudinal subset of patients that link anti-Jo-1 antibody levels to muscle, joint, lung, and global disease activity.

• Authors: Kerry B Stone, Chester V Oddis, Noreen Fertig, Yasuhiro Katsumata, Mary Lucas, Molly Vogt, Robyn Domsic, Dana P Ascherman
• Journal: Arthritis and rheumatism (Arthritis Rheum) Vol. 56 Issue 9 Pg. 3125-31 (Sep 2007) ISSN: 0004-3591 [Print] United States
• PMID: 17763431 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Autoantibodies
• Histidine-tRNA Ligase

Topics

• Adult
• Aged
• Autoantibodies (blood)
• Enzyme-Linked Immunosorbent Assay
• Female
• Histidine-tRNA Ligase (immunology)
• Humans
• Male
• Middle Aged
• Myositis (blood, immunology)
• Retrospective Studies