Combined determination of Epstein-Barr virus-related antibodies and antigens for diagnosis of nasopharyngeal carcinoma.

BACKGROUND AND OBJECTIVE With the development of molecular biology in recent years, many indexes for detecting Epstein-Barr virus (EBV) have been developed. This study was to evaluate the diagnostic value of combined determination of EBV-related antibodies and antigens, including VCA-IgA, EA-IgA, EBV-DNase antibody and EBV-DNA, in diagnosing nasopharyngeal carcinoma (NPC). METHODS Serum and plasma samples from 160 untreated NPC patients and 76 healthy donors were collected. VCA-IgA and EA-IgA in the serum samples were detected by immunoenzyme staining method. Raji cells were stimulated by ortho-butanoic acid and croton oil to detect EBV-DNase antibody. The content of EBV-DNA in the plasma samples was detected by real-time fluorescence quantitative polymerase chain reaction (RQ-PCR). The diagnostic values of the indexes for NPC were evaluated. RESULTS The sensitivity and specificity for diagnosing NPC were 90.0% and 89.5% for VCA-IgA, 75.0% and 94.7% for EA-IgA, 76.3% and 90.8% for EBV-DNase antibody, 68.8% and 88.2% for EBV-DNA, and 98.8% and 84.2% for combined determination. The positive rates of VCA-IgA and EA-IgA had no relationship with clinical stage of NPC (p > 0.05); nevertheless, the positive rates of EBV-DNase antibody and EBV-DNA were related with clinical stage (p < 0.05). CONCLUSIONS The sensitivity of VCA-IgA and the specificity of EA-IgA are the highest while detecting solely. Combined determination could improve the diagnostic sensitivity and accuracy for NPC. EBV-DNase antibody and EBV-DNA could be helpful to evaluate the course of disease and classify the clinical stage of NPC.