Characteristics of Japanese patients with systemic sclerosis complicated with calcinosis

Calcinosis is often observed in systemic sclerosis (SSc), but its pathogenesis remains unclear. The aim of the present study was to explore the association of clinical features with calcinosis in patients with SSc.

A retrospective cohort study was performed analyzing 416 SSc patients from our SSc database. We examined the clinical features with relation to calcinosis and SSc.

Calcinosis was observed in 24.0% of patients with SSc. The group with calcinosis comprised more female patients (P < 0.05) and diffuse cutaneous types (P < 0.001) than the group without calcinosis. Complications of Raynaud's phenomenon (P < 0.05), nail fold bleeding (NFB) (P < 0.001), peripheral bone resorption (P < 0.001), myositis (P < 0.001), and pulmonary hypertension (P < 0.05) were more frequently observed in patients with calcinosis compared with those without calcinosis. The group with calcinosis had a higher modified Rodnan total skin-thickness score (mRSS) than the group without calcinosis (P < 0.001). The factors that affected calcinosis in multivariable analysis were peripheral bone resorption (partial correlation coefficient 0.46, 34%), anti-Scl-70 antibody (partial correlation coefficient 0.29, 20%), diffuse type (partial correlation coefficient 0.34, 16%) and NFB (partial correlation coefficient 0.23, 11.2%).

Calcinosis in SSc is associated with Raynaud's phenomenon, NFB, and pulmonary hypertension, so peripheral circulatory insufficiency seems to be one of the causes of calcinosis. Furthermore, as it is related to mRSS and the diffuse cutaneous type, common factors related to skin fibrosis are considered to be involved.