Diagnostic value of cytokeratin 19 fragment in nasopharyngeal carcinoma

Abstract

To explore the clinical significance of cytokeratin 19 fragments test in the diagnosis of nasopharyngeal carcinoma. The study included 102 cases of nasopharyngeal carcinoma, 90 cases of nasal polyp/nasopharyngitis, and 150 healthy individuals. RT-PCR was used to detect CK19 mRNA expression and Western blot to detect CK19 fragment protein expression in tissues of nasopharyngeal carcinoma. Expression of CK19-2G2 was examined by immunohistochemistry. Chemiluminescence analysis was used to detect the serum levels of CK19-2G2, and ELISA to detect that of EB-VCA IgA. Among 102 cases of nasophryngeal carcinoma, 64 showed CK19 mRNA expression by RT-PCR, 60 showed CK19 protein fragments in tumor tissues by Western blot, and 66 showed expression of CK19-2G2 by immunohistochemistry in nasopharyngeal carcinoma, including strong positivity in 20 cases, moderate in 34 cases and weak in 12 cases. The sensitivity and specificity of CK19-2G2 in the diagnosis of nasopharyngeal carcinoma were 49.0% and 89.2%, and those of EB-VCA IgA were 52.9% and 85.4%, respectively. The combined detection of CK19-2G2 and EB-VCA IgA increased the sensitivity to 73.5% while the specificity remained at 80.0%. High levels of CK19-2G2 fragment expressed in tissue and serum are present in patients with nasopharyngeal carcinoma. The serum level of CK19-2G2 is helpful in the diagnosis of nasopharyngeal carcinoma. Furthermore, the combination of serum CK19-2G2 and EB-VCA IgA improves the detection sensitivity.