Experimental validation of the complement protein C3a down expression in the plasma of patients with squamous cell carcinoma of the penis

Abstract Objectives We have previously shown the importance of the complement system in differentiating between patients with squamous cell carcinoma of the penis (SCCP) and controls. These patients had low expression of C3a and C4 fragments. Therefore, in this study, we investigated the complement protein C3a as a potential circulating biomarker in these patients by a commercially available enzyme-linked immunosorbent assay (ELISA) test. Patients and methods Plasma samples from 39 patients with SCCP, 15 patients with prostate cancer, and 50 healthy male subjects were evaluated using the ELISA—Bioscience OptEIA Kit human anti-C3a (BD). The nonparametric Mann-Whitney test was used for comparison of means among the groups. Results The complement protein C3a was found down expressed in patients with SCCP ( P