Electrochemical impedance spectroscopy analysis of immunoglobulin G in patients with gastric cancer

AIM: To study whether alterations in the glycosylation of immunoglobulin G (IgG) as defined by an electrochemical impedance IgG analysis have a diagnostic potential in gastric cancer. Methods: Serum samples were obtained from patients with histologically verified gastric carcinoma and healthy blood donors. A lectin enzyme-linked immunosorbent assay-based glycoprofiling of IgG was performed using affinity purified IgG and lectins of various sugar specificities. Electrochemical measurements were carried out using 12.6 mm₂ gold screenprinted electrodes DRP-220BT (DropSens, Spain). The measurement of impedance has been performed using Impedance Analyzers 6500B series. The sensitivity and specificity of differences between cancer patients and controls were evaluated by a receiver operating characteristic (ROC) curve analysis. All calculations and comparisons were performed using the SPSS 15.0 software. Results: A significant difference in electrochemical impedance parameters between cancer patients and controls was established (P = 0.01). This study revealed a rather high specificity (90%) and sensitivity (72.7%) for gastric cancer with 80.9% accuracy of diagnostics. The impedance values positively correlated with the reactivity of purified IgG to fucose-specific lectin (P<;0.01) suggesting that the impedance changes observed in cancer are related to the aberrant glycosylation of IgG. Conclusion: This is the first report indicating that a total serum IgG impedance analysis may be a promising technique for stomach cancer detection.