Periostin overexpression in scleroderma cardiac tissue and its utility as a marker for disease complications

Objective: To evaluate the levels of periostin in patients with systemic sclerosis (SSc) and their association with features of systemic sclerosis. Methods The levels of periostin were assessed in the serum of 106 SSc patients and 14 healthy controls, and by immunofluorescence staining in cardiac tissue from 4 SSc patients and 4 healthy controls. Serum periostin was measured via enzyme-linked immunosorbent assay, and the natural logarithm of periostin (log-periostin) was calculated. Results were analyzed using unpaired t-test or one-way ANOVA followed by Tukey’s multiple comparisons tests, and Pearson’s test for correlations. Cardiac tissue from SSc patients and controls was stained for periostin and co-stained for periostin and collagen type I using immunofluorescence. Results Periostin levels were higher in patients with SSc compared to controls, and directly correlated to modified Rodnan skin score and echocardiography parameters of left ventricular measurements. Immunofluorescence staining in SSc cardiac tissue showed patchy periostin expression in all SSc patients, but not in controls. Furthermore, there was extensive periostin expression even in areas without collagen deposition, while all established fibrotic areas showed co-localization of collagen and periostin. There was no association between periostin levels and interstitial lung disease, pulmonary hypertension or other vascular complications. Conclusion Periostin is elevated in SSc cardiac tissue in vivo and circulating levels of periostin are increased in SSc, correlating with the extent of disease duration, degree of skin fibrosis, and left ventricular structural assessments. Periostin may be a potential biomarker that can provide further pathogenic insight into cardiac fibrosis in SSc.