Determinants of plasma calretinin in patients with malignant pleural mesothelioma

Abstract

Objective: Calretinin is a well-known immunohistochemical tissue marker in the diagnosis of malignant mesothelioma. Promising results also indicate the use in early detection. In the present cross-sectional survey, correlations of calretinin plasma levels with clinical features were investigated. Plasma samples of 60 patients with malignant pleural mesothelioma (MPM) and 111 cancer-free controls formerly exposed to asbestos were compared. Calretinin concentrations were determined in plasma using an enzyme-linked immunosorbent assay (ELISA).

Results: The median concentration was higher in MPM patients than in controls (0.79 vs. 0.23 ng/ml; p < 0.0001). Patients with epithelioid MPM or biphasic MPM had higher calretinin plasma levels than patients with sarcomatoid MPM. Strong expression of calretinin in the tumor tissue was associated with higher plasma levels. Preoperative patients showed higher levels of calretinin than patients after thoracic surgery (1.20 vs. 0.67 ng/ml; p = 0.096). The suitability of plasma calretinin has been confirmed as a tumor marker in the differential diagnosis of epithelioid MPM. The value of plasma calretinin for therapy monitoring or as a prognostic marker should be further investigated.

Keywords: Enzyme-linked immunosorbent assay; Malignant pleural mesothelioma; Molecular marker; Plasma calretinin; Tissue staining.

Fig. 1

Comparison of calretinin plasma levels in patients with malignant pleural mesothelioma (MPM), matched controls, epithelioid MPM, sarcomatoid MPM, and biphasic MPM (a); Comparison of calretinin plasma levels in male and female MPM patients (b); Comparison of calretinin plasma levels in pre- and postoperative samples (c); Comparison of calretinin plasma levels in patients with high staining response (H-score = 3) and low or moderate staining response (H-score < 3) of tumor tissue in preoperative samples only (d)