EVALUATION OF COMBINED EBNA1-IgA AND EA-IgG ASSAYS IN SEROLOGICAL DIAGNOSIS OF NASOPHARYNGEAL CARCINOMA

摘要

Objective: To evaluate the value of combined assays of serum EBNA1-IgA and EA-IgG for serological diagnosis of nasopharyngeal carcinoma (NPC). Methods: The serum EBNA1-IgA and EA-IgG were tested by use of ELISA for 56 patients with NPC and 58 healthy adults. The sensitivity, specificity, positive predictive value, accuracy rate and odds ratio of the 2 tests used singly or in combination were compared with each other. Results: The sensitivity of EBNA1-IgA test (91.09%) was higher than that (87.50%) of EA-IgG test. The specificity of EA-IgG test (87.93%) was higher than that (84.48%) of EBNA1-IgA test. The combined usage of EBNA1-IgA and EA-IgG could enhance the specificity (94.83%), predictive value of a positive test (0.9375), likelihood ratio of a positive test (15.5435) and odds ratio (75.0) for serological diagnosis of NPC. Forty-five NPC patients showed positivity to EBNA1-IgA and EA-IgG concurrently. A positive EA-IgG reaction was demonstrated in 4 out of 5 NPC patients with negative EBNA1-IgA result and a positive EBNA1-IgA reaction in 6 out of 7 NPCpatients with negative EA-IgG result as well. Conclusion: Though high sensitivity and specificity could be obtained by EBNA1-IgA and EA-IgG test, respectively, the combined use of these 2 tests is able to enhancing the reliability of serological diagnosis of NPC. The majority of NPC patients showed positivity to ENBA1-IgA and EA-IgG concurrently. There is a complementary effect through using EBNA1-IgA and EA-IgG for serological diagnosis of NPC.