Interleukin-6 (IL-6) is overexpressed in the serum and the skin of patients with systemic sclerosis (SSc). (A) Patients with SSc and early disease (less than 5 years) had increased IL-6 serum levels compared with age- and sex-matched healthy controls (P = 0.006). IL-6 was detected ex vivo by immunohistochemistry in patients with SSc (C) compared with controls (B). Positive staining for IL-6 was observed in the epidermis and in several cell types of the dermis. In addition, the intensity of immunostaining assessed by the ImageJ software was significantly increased in patients with SSc compared with controls (P = 0.0007) (D), particularly in those with early disease (P = 0.008) (E). Bars represent median(Q1,Q3).