Objective: To investigate the value of combined detection of Epstein-Barr virus (EBV) VCA/IgA, EA/IgA, Rta/IgG and EBNA1/IgA in serodiagnosis of nasopharyngeal carcinoma (NPC).
Methods: Serum samples obtained from 211 untreated patients with NPC and 203 non-NPC ENT patients were examined for the presence of VCA/IgA and EA/IgA by immunoenzymatic assay and for Rta/IgG and EBNA1/IgA by enzyme-linked immunosorbent assay (ELISA). The receiver operating characteristic (ROC) curve was generated to confirm the cutoff values of different antibodies. The evaluation indexes of combined detection of multiple antibodies used for serodiagnosis of NPC were calculated with compounded positive judgment method.
Results: Compared to a single antibody, combined detection achieved a higher sensitivity and specificity. The sensitivity of VCA/IgA + Rta/IgG + EBNA1/IgA (98.1%) was higher than the other 3 combinations with a specificity, accuracy, Youden index and positive predictive value (PPV) of 88.7%, 93.5%, 0.868 and 90.0%, respectively. The combination of EA/IgA+Rta/IgG+EBNA1/IgA had the highest specificity (95.1%), accuracy (94.9%), Youden index (0.899) and PPV (95.2%), with a sensitivity of 94.8%, suggesting its higher accuracy in the serodiagnosis of NPC. Combined detection of the 4 antibodies had the highest sensitivity (98.6%) with a specificity, accuracy, Youden index and PPV of 88.2%, 93.5%, 0.868 and 89.7%, respectively.
Conclusions: Combined detection of Rta/IgG against immediate early antigens, EA/IgA against early antigens, VCA/IgA against late antigens, and EBNA1/IgA against latent antigens provides better understanding of the expression profiles of EBV lytic and latent antigens with excellent complementarity, and may serve as an optimal combination for NPC serodiagnosis.