Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy and uncontrolled cutaneous and internal organs fibrosis. Diagnosis of SSc in an early phase can be difficult because of a lack of typical symptoms. The delay in diagnosis and treatment of SSc may lead to uncontrolled progression of the disease, thus identification of possible early indicators of skin and organ involvement to prevent their further damage is necessary. The aim of this study is to review the latest biomarkers of organ involvement in SSc. In patients with lung fibrosis lung-epithelial-derived surfactant protein (SP-D), the glycoprotein Krebs von den Lungen-6 (KL-6), and chemokine ligands 2, 4 and 18 (CCL2, CXCL4, CCL18) are elevated, while in patients with skin fibrosis serum levels of heat shock protein 27 (Hsp27), interleukin 16 (IL-16), and IgG-galactosylation ratio are increased. Adiponectin concentration is inversely correlated with the intensity of cutaneous fibrosis. Skin gene profiling also seems very promising. In patients with heart involvement increased serum levels of brain natriuretic peptide (BNP) are present, as well as raised Midkine and Follistatin-like 3 (FSTL3) proteins, ratios of Cu/Se and ceruloplasmin(CP) /Circulating selenoprotein P(SELENOP) and higher whole blood viscosity level. Elevated calprotectin levels are found in individuals with gastrointestinal involvement. Increased levels of chemerin and ARA autoantibodies are associated with renal involvement, whereas high levels of adhesion molecules are found in patients with scleroderma renal crisis (SRC). Currently there are no biomarkers in use that can specifically identify the early involvement of organs.
Keywords: autoantibodies; biomarker; fibrosis; systemic sclerosis.