Conclusion
The combination of macrophage migration inhibitory factor and Epstein-Barr virus viral capsid antigen increases the specificity and positive predictive value of detecting nasopharyngeal carcinoma and improves the diagnostic accuracy of nasopharyngeal carcinoma in high-risk individuals.
Methods
The expression levels of macrophage migration inhibitory factor in nasopharyngeal carcinoma cell lines, tumor tissues, and plasma were measured by real-time polymerase chain reaction, Western blotting, enzyme-linked immunosorbent assay, and immunohistochemistry. Plasma Epstein-Barr virus viral capsid antigen was determined by immunoenzymatic techniques.
Results
Both the messenger RNA and protein expression levels of macrophage migration inhibitory factor were upregulated in nasopharyngeal carcinoma cell lines and nasopharyngeal carcinoma tissues. Macrophage migration inhibitory factor in plasma was significantly elevated in patients with nasopharyngeal carcinoma compared to Epstein-Barr virus viral capsid antigen-negative and Epstein-Barr virus viral capsid antigen-positive healthy donors. The combination of macrophage migration inhibitory factor and Epstein-Barr virus viral capsid antigen was better for diagnosing nasopharyngeal carcinoma (area under receiver operating characteristic curve = 0.925, 95% CI: 0.898-0.951) than macrophage migration inhibitory factor (area under receiver operating characteristic curve = 0.778, 95% CI: 0.732-0.824) and Epstein-Barr virus viral capsid antigen. Combining macrophage migration inhibitory factor and Epstein-Barr virus viral capsid antigen had higher specificity (82.40% vs 69.96%) and higher positive predictive value (79.17% vs 67.44%) without an obvious reduction in sensitivity (95.25%) compared to Epstein-Barr virus viral capsid antigen alone. Macrophage migration inhibitory factor was highly expressed in nasopharyngeal carcinoma cell lines, whereas it was not associated with Epstein-Barr virus infection. The level of macrophage migration inhibitory factor in plasma was not related to the titer of Epstein-Barr virus viral capsid antigen.