ABSTRACT
Objective To investigate the role of real-time PCR(qPCR) assay for EBNA fragments in quantitative detection of Epstein-Barr virus(EBV)DNA loads and the diagnose value of combining EBNA assay with common qPCR assay (designed on Bamh1-W fragments) in Nasopharyngeal Carcinoma (NPC) patients Methods EBV DNA loads of 234 blood samples(66 NPC samples included)were detected using two methods and DNA loads inside and outside cells were detected respectively. Positive rate obtained through different methods was compared. Regression analysis and t test were used to validate the methodology. Results Positive rate of EB-NA assay(53.42% in all samples and 51.52% in NPC samples)was lower than that of Bamh1-W assay(69.23%in all samples ,71.21% in NPC samples),however the combination of two methods could enhance the positive rate(70.94% in all samples,72.73% in NPC samples),especially in NPC samples. The correlation R2 of EBNA assay and Bamh1-W assay was 0.577(P < 0.05)and the difference was statistically significant. In NPC samples , R2 was 0.828 (P > 0.05) and it showed good correlation but the difference was not statistically significant. Conclusions The combination of EBNA assay and Bamh1-W assay can improve the positive rate in EBV DNA loads detection and its efficiency is more significant in NPC patients ,which shows significance in EBV DNA loads quantification and in the auxiliary diagnosis of NPC.
ABSTRACT
Objective To investigate the role of real-time PCR(qPCR) assay for EBNA fragments in quantitative detection of Epstein-Barr virus(EBV)DNA loads and the diagnose value of combining EBNA assay with common qPCR assay (designed on Bamh1-W fragments) in Nasopharyngeal Carcinoma (NPC) patients Methods EBV DNA loads of 234 blood samples(66 NPC samples included)were detected using two methods and DNA loads inside and outside cells were detected respectively. Positive rate obtained through different methods was compared. Regression analysis and t test were used to validate the methodology. Results Positive rate of EB-NA assay(53.42% in all samples and 51.52% in NPC samples)was lower than that of Bamh1-W assay(69.23%in all samples ,71.21% in NPC samples),however the combination of two methods could enhance the positive rate(70.94% in all samples,72.73% in NPC samples),especially in NPC samples. The correlation R2 of EBNA assay and Bamh1-W assay was 0.577(P < 0.05)and the difference was statistically significant. In NPC samples , R2 was 0.828 (P > 0.05) and it showed good correlation but the difference was not statistically significant. Conclusions The combination of EBNA assay and Bamh1-W assay can improve the positive rate in EBV DNA loads detection and its efficiency is more significant in NPC patients ,which shows significance in EBV DNA loads quantification and in the auxiliary diagnosis of NPC.
ABSTRACT
Elevated levels of circulating cell-free Epstein-Barr virus (EBV) DNA have been detected in plasma and serum samples from nasopharyngeal cancer (NPC) patients by quantitative real time PCR (qPCR) test. This qPCR test for circulating EBV DNA was found to be useful in the clinical management of NPC patients. For instance, EBV DNA qPCR test has good sensitivity and specificity in the detection of NPC at disease onset. Increase of the viral DNA load was found in NPC patients at late stages of disease. High EBV DNA load at disease onset or detectable viral load post-treatment was associated with poor survival or frequent relapse in NPC patients. Residual EBV DNA load after primary treatment could be a useful indicator to justify adjuvant chemotherapy. The qPCR test might also be applied to define a poor prognostic group in patients at early stage (I/II) for implementing concurrent chemo-radiotherapy (chemo-RT) to improve patients' outcome. The test is also useful to monitor distant metastases or response to radiotherapy, chemo-RT or surgery. Supplementary tests, however, are needed to pick up EBV negative WHO type I NPC and test improvement is needed to increase sensitivity in detecting stage I disease and local recurrence.
