ABSTRACT
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.
Subject(s)
Antibodies, Viral/blood , Antigens, Viral/blood , Herpesvirus 4, Human/immunology , Nasopharyngeal Neoplasms/diagnosis , Nasopharyngeal Neoplasms/virology , Adult , Aged , DNA, Viral/blood , Female , Humans , Immunoglobulin A/blood , Male , Middle Aged , Nasopharyngeal Neoplasms/pathology , Neoplasm Staging , Sensitivity and SpecificityABSTRACT
BACKGROUND & OBJECTIVE: Selenium (Se), an antioxidant, is an essential trace element to human body. It can be used as an anti-aging agent and a tumor cell proliferation inhibitor. To further investigate the effect of selenium in cancer prevention, the authors observed the influence of Se-rich rice extract on the transformation of umbilical blood B lymphocytes stimulated by Epstein-Barr virus (EBV) and expression of EBV early antigen(EBV-EA) in Raji cells. METHODS: (1) Se-rich rice and general rice extract (dilution of 1:4 or 1:8) were added to mixture of EBV, and then umbilical blood mononuclear cells were added. Lymphoblasts transformation test was then performed. The inhibition rate of B lymphocytes transformation was calculated. (2) Raji cells stimulated by butyrate and croton oil were incubated with Se-rich rice extract. The EBV-EA positive expression rate and the inhibition rate were counted using indirect immunological flurescence method. RESULTS: The transformation of umbilical blood B lymphocytes stimulated by EBV was significantly inhibited by Se-rich rice extract at a concentration of 0.11 g/ml (1:8 diluted). The inhibition rate was 83.4% (P < 0.01), which was significantly higher than that of the control rice (63.1%) (P < 0.05). Se-rich rice extract showed significant inhibition on EBV-EA in Raji cells. As the extract concentration was at 0.016 microgram/ml, 0.078 g/ml, and 0.388 microgram/ml, the inhibition rates of EA were 2.85%, 12.88%, and 20.75%, respectively. CONCLUSION: The transformation of umbilical blood B lymphocytes stimulated by EB virus and expression of EBV-EA in Raji cells may be significantly inhibited by Se-rich rice extract, suggesting that Se-rich rice can be used for preventing nasopharyngeal carcinoma.
