Background and Objectives Visfatin is an adipocytokine that supports B-lymphocyte precursor maturation, and also takes part in regulation of inflammation. Anti-histidyl-tRNA syntethase antibodies (anti-Jo-1) are the most frequent myositis specific autoantibodies. We have shown increased serum levels of B-cell activating factor of the TNF family (BAFF) in dermatomyositis (DM) and anti-Jo-1-positive polymyositis (PM) patients and its association with disease activity. Here we evaluated serum levels of visfatin in anti-Jo-1-positive PM/DM patients, its expression in muscle tissue and investigated potential relations between visfatin, BAFF, disease activity and anti-Jo-1 autoantibody levels.
Material and Methods ELISA was used for detection of visfatin, BAFF and anti-Jo-1 serum samples in patients with PM (n = 27), DM (n = 11) and in 25 age and sex matched healthy controls. Paired samples from two different time points of sixteen patients were available. Disease activity was evaluated by myositis disease activity assessment visual analogue scales (MYOACT) and by serum levels of creatine phosphokinase (CPK), aminotranspherases (ALT, AST), lactate dehydrogenase (LDH) and myoglobin. Visfatin was detected by immunohistochemistry in muscle tissues of PM/DM patients (n = 5/5) and compared with non-inflammatory control muscle tissues from patients with myasthenia gravis (n = 5).
Results Serum visfatin and BAFF levels were significantly higher in myositis patients (medians 1.9 and 1.4 pg/l) compared to healthy controls (1.3 and 1.0 pg/l; p < 0.02 and p = 0.003) and were associated with clinical muscle activity (rs = 0.39; p < 0.02 and rs = 0.34; p = 0.04). Trend for correlation of both visfatin and BAFF with the global disease activity was present. Serum levels of visfatin were associated with LDH (rs = 0.39, p < 0.02), whereas BAFF correlated with CPK, myoglobin and AST (rs = 0.51, 0.57 and 0.39; p < 0.05 for all). Positive correlation between visfatin and BAFF serum levels was found in patients with myositis (rs = 0.44; p < 0.01) but was negative in healthy controls (rs = –0.54; p < 0.001). No association between visfatin and anti-Jo-1 autoantibody levels was found while BAFF positively correlated with anti-Jo-1 levels (rs = 0.85; p = 0.001). Visfatin levels decreased significantly over time (p = 0.01), while the decrease of BAFF was not significant. Visfatin expression was present in endomysial and perimysial inflammatory infiltrates of muscle tissues from patients with PM/DM compared with no expression in controls.
Conclusions These results demonstrate that serum levels of visfatin, similarly to BAFF, associate with disease activity in patients with myositis. Increased visfatin levels and expression in inflamed muscle tissues support its potential role in the pathogenesis of idiopathic inflammatory myopathies.
Acknowledgement This study was supported by Research Project No. 00023728 and Internal Grant Agency of Ministry of Health of the Czech Republic NT/12438–4.