Serum Cytokeratin 18 as a Metastatic and Therapeutic Marker for Extramammary Paget's Disease.

Extramammary Paget's disease (EMPD) is a rare cutaneous adenocarcinoma with unfavourable prognosis once it becomes invasive. A tumour marker that reflects disease progression is required for adequate management of EMPD. Cytokeratin 18 is highly expressed in many types of cancer and its soluble forms are detected by M30 (for caspase-cleaved form) and M65 (for both caspase-cleaved and intact forms) assays. We report here that tumour cells of EMPD in both lesional skin and lymph node metastasis are immunohistochemically positive for CK18, and the baseline serum M30 and M65 levels in patients with metastatic EMPD are significantly higher than those in non-metastatic patients. In addition, serial serum M30 and M65 levels might reflect recurrence of EMPD and response to chemotherapy. These results suggest that serum CK18 levels may be a useful tumour marker for advanced EMPD.

Serum cold-inducible RNA-binding protein levels as a potential biomarker for systemic sclerosis-associated interstitial lung disease.

Systemic sclerosis (SSc) is a complex autoimmune disease characterized by fibrotic, inflammatory, and vascular dysfunction. Danger-associated molecular patterns (DAMPs)-mediated inflammasome activation has been reported to be involved in the pathogenesis of SSc. Cold-inducible RNA-binding protein (CIRP) is newly identified as a DAMP. Here we examined the clinical significance of serum levels of CIRP in 60 patients with SSc and 20 healthy control patients (HCs) using an enzyme-linked immunosorbent assay. Serum CIRP levels in diffuse cutaneous SSc (dcSSc) patients were significantly increased compared with limited cutaneous SSc (lcSSc) patients or HCs. When examining the relationship with SSc-specific parameters, serum CIRP levels with the presence of interstitial lung disease (ILD) were higher than those without ILD. In detail, serum CIRP levels correlated negatively with the percent predicted diffusing capacity for carbon monoxide and positively with levels of Krebs von den Lungen-6. In addition, elevated serum CIRP levels declined along with decreased SSc-ILD activity in patients who received immunosuppressive therapy. These results suggest that CIRP may play a role in the development of ILD in SSc. Moreover, CIRP could serve as a useful serological marker of SSc-ILD in terms of disease activity and therapeutic effects.