Quantitative Analysis Of Cell-free Epstein-Barr Virus DNA In Serum In Patients With Nasopharyngeal Carcinoma

Objective To construct quantitative analysis of cell-free Epstein-Barr virus ( EBV) DNA levels in serum in nasopharyngeal carcinoma (NPC) , In order to explore the valuable of EBV-DNA levels in the serum of nasopharyngeal carcinoma patients with diagnose, prediction prognostication ,therapeutic effect .Methods The copies of EBV-DNA in 101 serum samples of NPC pa- tients were examined , and compared with 49 normal controls. Among NPC patients of 101 ,Ⅰstage was 3 patients,Ⅱstage was 11patients ,Ⅲstage was39 patients,Ⅳstage was 48patients.Designed primer and probe according to cell- free Epstein-Barr virus DNA gene order in serum in nasopharyngeal carcinoma,amplificated BamHI- W gene order of EBV-DNA with PCR, then cloned to pGEM-T Easy vector, constructed plasmid standard preparation ;Established flu-orescence quantitative polymerase chain reaction (FQ-PCR), .Quantitative analy-sis of Epstein-Barr virus DNA in serum in patients with nasopharyngeal car-cinoma .At the same time , serum VCA/IgA was also measured in NPC with enzyme immunoassay.Resμlts 1.Serum EBV-DNA levels and positive rate in NPC before treat-ment average were 58 400 copies/ ml and 90.6% (91/101) ,after treatment (1243.36 copies/ml,18.75 % 8/44) and serum EBV-DNA levels and positive rate ofcontrols was0 copies/ml and 0%(0/49) , there was significant difference between EBV-DNA levels of NPC befort treatment and after treatment and controls(0copies/ml) ( P <0.01) . There was significant difference positive rate between NPC befort treatment and after treatment and controls ( P <0.05) . There was no significant difference between serum EBV-DNA levels and posi-tive rate in NPC after treatment and normal controls .(Mann-Whitney Utest, P = 0.256 ;chi square test, P = 0.223). Serum VCA/IgA positive rate in NPC was 83.1%(84 /101) ,compared with normal controls positive rate was 4.1%, (2/49),there was remarkble increased between NPC and normal controls (P< 0.05).EBV-DNA positive rate in NPC was 90.6%,then serum VCA/IgA positive rate in NPC was 83.1% , the detection of EBV-DNA levels was more sensi- tive than serum VCA/IgA .2. Positive rate in NPC ofⅢ~Ⅳ(89.7%, 35/39; 89.6%,43/48) were significantly higher than that in NPC ofⅠ~Ⅱ(72.7%8/11).There was remarkble difference(P <0.01). Serum EBV-DNA level was signi- ficantly increased in TNM stage in NPC.Ⅰ(3390±1540 copies/ ml) ,Ⅱ(11802±5603 copies/ ml) ,Ⅲ(56488±27234 copies/ ml) andⅣ(722275±321351 copies/ ml),there was significantly difference of EBV-DNA in difference stages of NPC(P<0.005). 3.Serum VCA/IgA S/CO in NPC befort treatment average (3.8158 S/CO≥1positive,<1 negitive),was a litter bit higher than after (3.1261,P>0.05)). There was no significant different between serum VCA/IgA S/CO in NPC befort and after treatment (P>0.05)There was remarkable increased between serum VCA/IgA S/CO in NPC and normal controls (P< 0.05).Serum EBV-DNA levels in NPC before treatment average 58 400 copies/ ml were significantly higher than that in NPC after treatment median 1243.36 copies/ ml ( P<0.05) and normal controls median 0 copies/ ml ( P<0.01).Conclusion 1.Succeed to construct quantitative analysis of cell-free Epstein-Barr virus ( EBV) DNA levels in serum in nasopharyngeal carcinoma (NPC).The resμlt of FQ-PCR was stabilization, accuration , high sensitivity , good repeatability and specificity.2. Serum EBV-DNA may use for detecting efects of treatment in NPC,it was more valuable than VCA/IgA. 3.Quantitative analy-sis of cell-free Epstein-Barr virus ( EBV) DNA levels in serum in nasopharyn-geal carcinoma may use as a method for diagnose, prediction prognostication , clinical stages ,efects of radiotherapy and tumor load.