Chemokine CCL27 is a novel plasma biomarker for identification the nasopharyngeal carcinoma patients from the Epstein-Barr virus capsid antigen-specific IgA seropositive population.

BACKGROUND: To investigate the predictive value of chemokine CCL27 for identifying early stage nasopharyngeal carcinoma (NPC) patients within a population seropositive for Epstein-Barr virus (EBV) capsid antigen-specific IgA (VCA-IgA). METHODS: CCL27 in plasma samples from 104 NPC patients, 112 VCA-IgA-positive healthy donors, and 140 VCA-IgA-negative normal subjects was measured by ELISA. Expression of CCL27 in nasopharyngeal tissue from 20 VCA-IgA-positive healthy donors and 20 NPC patients was examined by immunohistochemical staining. RESULTS: Levels of CCL27 in the plasma of VCA-IgA-positive healthy donors (607.33 ± 218.81 pg/ml) were significantly higher than the levels in all NPC patients (437.09 ± 217.74, P = < 0.0001) and in the subset of patients with early stage NPC (463.85 ± 226.17, P = 0.0126). Plasma CCL27 levels were significantly lower in the VCA-IgA-negative normal subjects (358.22 ± 133.15 pg/ml) than in either the VCA-IgA-positive healthy donors (P < 0.0001) or the NPC patients (P = 0.0113). CCL27 protein was detected in 16 of 20 (80%) nasopharyngeal tissue samples from VCA-IgA-positive healthy donors and in 3 of 20 (15%) tumor tissue samples from NPC patients. There was no relationship between CCL27 levels and VCA-IgA titers or plasma EBV DNA content. Receiver operating characteristic (ROC) curves demonstrated that plasma CCL27 levels had a sensitivity of 67.00%, a specificity of 73.10%, and an area under the ROC of 0.725 (95% confidence interval [CI]: 0.657-0.793) for distinguishing between NPC patients and VCA-IgA-positive healthy donors. Further analysis showed that CCL27 levels could distinguish between early stage NPC patients and VCA-IgA-positive healthy donors with an area under the ROC of 0.712 (95% CI: 0.560-0.865), a sensitivity of 59.80%, and a specificity of 84.60%. CONCLUSIONS: Chemokine CCL27 could successfully identify NPC patients within a VCA-IgA-positive population.