Serum periostin levels are correlated with progressive skin sclerosis in patients with systemic sclerosis

Background Periostin, a matricellular protein, serves as a regulator of wound healing and fibrosis. The role of periostin in the pathogenesis of systemic sclerosis (SSc) is unknown. Objective To determine periostin levels in association with severity of skin fibrosis in patients with SSc. Methods Expression of periostin was immunohistochemically examined in skin obtained from patients with SSc and healthy controls. Enzyme-linked immunosorbent assay was performed to evaluate serum periostin levels in association with clinical characteristics in 56 patients with SSc [diffuse cutaneous SSc (dSSc), n = 16; and limited cutaneous SSc (lSSc), n = 40] and 66 healthy controls. Results Periostin was strongly expressed in the affected dermis from patients with SSc. Periostin was colocalized in alpha-smooth muscle actin-positive myofibroblasts and platelet endothelial cell adhesion molecule-1-positive endothelial cells in SSc dermis. Serum levels of periostin in patients with dSSc were markedly elevated compared with those in patients with lSSc and control subjects. Patients with lSSc had increased periostin levels compared with healthy controls. In addition, significantly higher levels of periostin were observed in patients with dSSc with disease duration <= 5 years compared with those with disease duration > 5 years. Furthermore, the modified Rodnan total skin thickness score (MRSS) was positively correlated with periostin levels in patients with SSc. Serial analysis revealed a correlation between periostin and MRSS; namely, MRSS decreased in line with decreased periostin levels in some patients with dSSc as the disease progressed. Conclusion An elevated periostin level in patients with SSc is associated with severity of skin sclerosis. Periostin may be a potential biomarker for progressive skin fibrosis in SSc.