Plasma Macrophage Migration Inhibitory Factor and CCL3 as Potential Biomarkers for Distinguishing Patients with Nasopharyngeal Carcinoma from High-Risk Individuals Who Have Positive Epstein-Barr Virus Capsid Antigen-Specific IgA

PURPOSE: The purpose of this study was to identify novel plasma biomarkers for distinguishing nasopharyngeal carcinoma (NPC) patients from healthy individuals who have positive Epstein-Barr virus (EBV) viral capsid antigen (VCA-IgA). MATERIALS AND METHODS: One hundred seventy-four plasma cytokines were analyzed by a Cytokine Array in eight healthy individuals with positive EBV VCA-IgA and eight patients with NPC. Real-time polymerase chain reaction, Western blotting, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry were employed to detect the expression levels of macrophage migration inhibitory factor (MIF) and CC chemokine ligand 3 (CCL3) in NPC cell lines and tumor tissues. Plasma MIF and CCL3 were measured by ELISA in 138 NPC patients, 127 EBV VCA-IgA negative (VN) and 100 EBV VCA-IgA positive healthy donors (VP). Plasma EBV VCA-IgA was determined by immunoenzymatic techniques. RESULTS: Thirty-four of the 174 cytokines varied significantly between the VP and NPC group. Plasma MIF and CCL3 were significantly elevated in NPC patients compared with VN and VP. Combination of MIF and CCL3 could be used for the differential diagnosis of NPC from VN cohort (area under the curve [AUC], 0.913; sensitivity, 90.00%; specificity, 80.30%), and combination of MIF, CCL3, and VCA-IgA could be used for the differential diagnosis of NPC from VP cohort (AUC, 0.920; sensitivity, 90.00%; specificity, 84.00%), from (VN+VP) cohort (AUC, 0.961; sensitivity, 90.00%; specificity, 92.00%). Overexpressions of MIF and CCL3 were observed in NPC plasma, NPC cell lines and NPC tissues. CONCLUSION: Plasma MIF, CCL3, and VCA-IgA combination significantly improves the diagnostic specificity of NPC in high-risk individuals.