Abstract: Objective To detect the expression level of Rta-IgG in the untreated patients with nasopharyngeal carcinoma(NPC).Methods The diagnostic kit for IgG antibody to EBV Rta(ELISA) was used to test serum samples derived from 274 patients that were within different clinical stages confirmed by pathology examination,and 353 healthy controls.Results Significant difference of Rta-IgG positive rate between NPC group and healthy control group was revealed(P<0.01).However,the expression levels of Rta-IgG in NPC patients' serum were irrelative with the clinical stage of the tumor.The A value was significantly higher in NPC group than that in healthy control group(P<0.01).Conclusion Rta-IgG is a sensitive and specific serologic parameter for NPC diagnosis,but it is not a proper marker for evaluating the clinical stage of NPC.

Key words: Nasopharyngeal carcinoma(NPC), Rta-IgG, Clinical stage