EBV DNA定量分析在监测鼻咽癌转移和复发中的临床意义

背景与目的:EB病毒(Epstein-Barrvirus,EBV)感染与鼻咽癌关系密切,近年来,有报道鼻咽癌患者血浆/血清中可检测到游离EBVDNA,但血浆EBVDNA水平对判断放疗后鼻咽癌患者转移、复发的临床意义尚缺少大宗研究报道。本研究定量检测鼻咽癌放疗后随诊患者血浆EBVDNA含量,探讨其在监测鼻咽癌转移、复发中的临床意义。方法:选择在中山大学肿瘤防治中心门诊随诊的放疗后鼻咽癌患者90例,用荧光定量PCR方法检测血浆EBVDNA含量,比较转移、复发与持续缓解患者血浆EBVDNA拷贝数。结果:放疗后转移或复发患者血浆EBVDNA的检出率为96.7%(29/30),中位拷贝数为2650copies/ml(0～5900000copies/ml);而持续缓解组患者血浆EBVDNA检出率12%(7/60),中位拷贝数为0copy/ml(0～71000copies/ml),差异均有统计学意义(P<0.01)。3例临床持续缓解但有血浆EBVDNA升高患者,在随后的3～4个月随访中,证实有肿瘤转移或复发。结论:血浆EBVDNA李宇红,等.EBVDNA定量分析在646定量检测可能成为监测放疗后鼻咽癌患者肿瘤转移、复发的敏感肿瘤标记物。     

血浆EBV-DNA定量检测对复发/转移鼻咽癌患者的意义

[目的]探讨EBV-DNA在复发/转移鼻咽癌患者中表达特点及其临床意义.[方法]56例行EBV-DNA检测的复发/转移鼻咽癌患者56例,其中有25例患者为单纯局部复发,27例患者为单纯远处转移,4例患者为局部复发伴远处转移,另收集100例目前无复发证据的已治鼻咽癌患者作为对照.荧光定量PCR检测血浆EBV-DNA的表达水平.[结果]56例复发/转移鼻咽癌患者中血浆EBV-DNA阳性检出率为57.1％(32/56),阳性患者中EBV-DNA中位浓度为3.845×103copies/ml.单纯局部复发患者中,EBV-DNA阳性检出率为56.0％(14/25),单纯远处转移的患者中,EBV-DNA阳性检出率为51.8％(14/27),局部复发伴转移的患者中,EBV-DNA阳性率为100.00％(4/4).100例无复发证据的已治鼻咽癌患者中,EBV-DNA阳性检出率为4.0％(4/100),阳性患者中EBV-DNA中位浓度为1.79× 102copies/ml.[结论]在复发/转移的鼻咽癌患者中EBV-DNA有较高的检出率,且其表达水平较高,特异性高,对于EBV-DNA表达阳性且持续升高达≥1.0× 103copies/ml的已治鼻咽癌患者,应高度警惕复发及转移.     

血浆EBV DNA定量分析在监测鼻咽癌患者复发和转移中的价值

目的 探讨血浆EB病毒DNA(EBV DNA)含量在监测鼻咽癌患者放疗后复发和转移中的临床价值.方法 采用荧光定量PCR方法 检测81例放疗后随诊的鼻咽癌患者血浆EBV DNA含量,比较缓解组与复发、转移组血浆EBV DNA差异.结果 放疗后缓解组患者血浆EBV DNA阳性率为15.7%,中位拷贝数为0 copy/ml;放疗后复发或转移组患者血浆EBV DNA阳性率93.3%,中位拷贝数6 432 copies/ml,差异均有显著性(P<0.001).结论 血浆EBV DNA定量检测有可能成为监测鼻咽癌患者放疗后复发、转移的肿瘤标记物.     

VcA/IgA抗体对鼻咽癌诊断价值及预后探讨──附106例分析

 本文总结106例鼻咽癌患者放疗前后VCA/IgA抗体检测结果。放疗前VCA/IgA抗体总阳性率为84.0%,T1-T4分别为50.0%,73.3%,85.4%和96.8%.放疗后，鼻咽原发灶和颈部淋巴结消失，原发灶消失及颈淋巴结残存，原发灶和颈淋巴部均残存，远处转移，VCA/IgA抗体滴复阳性率分别为44.8%,70.0%,80.0%,100.0%.消失组与残存及转移组有显着差异（P<0.05）.此结果表明VCA/IgA检测对鼻咽癌诊断和预后有-定意义。     

18F-FDG PET/CT和MRI及血浆EB病毒水平对鼻咽癌局部复发的诊断价值研究

  目的  比较18F-FDG PET/CT、MRI在鼻咽癌局部复发和放疗后改变的鉴别诊断中的应用价值,并确定更合适的SUV_max诊断阈值,探索血浆EBV-DNA在发现鼻咽癌复发转移方面的意义。  方法  选取2015年1月至2020年2月期间放疗结束至少6个月后在福建省肿瘤医院进行复查的鼻咽癌患者208例,均进行MRI、PET/CT及EB病毒DNA检查（均在1个月内完成）。以活检病理结果或影像学的密切随访（至少1年）作为诊断鼻咽癌是否局部复发的标准,对患者的影像检查结果及相关参数进行比较分析。  结果  共有83例患者确诊为鼻咽癌局部复发,125例确诊为无局部复发,后者中77例伴有区域复发和（或）远处转移。PET/CT和MRI对鼻咽癌局部复发的诊断敏感性、特异性、准确性分别为89.2% vs. 67.5%,90.4% vs. 92.0%,89.9% vs. 82.2%。当诊断临界值SUV_max=3.85时,PET/CT的诊断准确性最高,与SUV_max=2.5相比,特异性（89.6% vs. 68.0%）和准确性（89.4% vs. 78.4%）均有显著提升。对纳入患者中治疗失败患者的EB病毒DNA分析发现,局部复发患者的血浆EBV-DNA检测敏感性低于区域复发或远处转移患者。局部复发肿瘤患者的SUV_max值与血浆EBV-DNA存在相关性。  结论  18F-FDG PET/CT对鼻咽癌局部复发和放疗后改变的鉴别诊断效能优于MRI。SUV_max诊断阈值设为3.85时可获得更好的诊断效能。血浆EBV-DNA检测在鼻咽癌区域复发和远处转移方面较灵敏,局部复发者的阳性率并不高,对这部分患者的诊断价值仅提供参考。      

鼻咽癌患者血浆EBVDNA水平和VCA—IgA检测的临床意义

目的：探讨鼻咽癌患者血浆EBVDNA水平和VCA—IgA联合检测对鼻咽癌早期诊断的临床价值。方法：用荧光定量PCR方法检测血浆EBVDNA水平，常规免疫酶法检测VCA—IgA抗体滴度。结果：68例鼻咽癌患者中，EBVDNA阳性率95．59％，中位拷贝数93× 10^4 copies／ml，VCA—IgA抗体阳性率92．65％，抗体滴度≥1：20；其他头颈肿瘤36例中，EBVDVA阳性率5．56％，中位拷贝数为0copies／ml，VCA—IgA抗体阳率36．11％，阳性滴度均≤1：20；健康对照组EBVDNA阳性率为35．56％，其滴度除3例≥1：40外，余均≤1：20。鼻咽癌患者中EBVDNA和VCA—IgA抗体阳性率显著高于对照组。结论：进-步证实EBV与鼻咽癌有密切关系；EBVDNA水平和VCA—IgA抗体滴度联合检测，有助于鼻咽癌的早期辅助诊断。     

鼻咽癌患者血浆游离EBV/DNA的定量检测及其临床意义

目的:探讨血浆EBV/DNA定量分析,在鼻咽癌早期诊断、临床分期、预后判断和监测放疗后转移复发中的临床意义.方法:采用荧光定量PCR方法定量检测经病理确诊为鼻咽癌的120例初治、90例放疗后随诊患者,其中包括60例放疗后持续缓解,30例远处转移和局部复发患者的血浆EBV/DNA含量.结果:初治、远处转移和局部复发的鼻咽癌患者血浆中游离的EBV/DNA检出率分别为96.0%、95.0%和100%,显著高于治疗后持续缓解鼻咽癌患者、健康对照者和非鼻咽癌的肿瘤患者;初治鼻咽癌患者各TNM分期之间血浆EBV/DNA拷贝数有显著统计学差异,晚期患者(Ⅲ Ⅳ)期血浆EBV/DNA中位拷贝数显著高于早期患者(I Ⅱ)期;初治患者治疗后已出现局部和远处转移者.治疗前血浆EBV/DNA中位数显著高于尚未出现复发转移患者:初治患者治疗前血浆EBV/DNA≥40 000拷贝/ml与＜40 000拷贝/ml两个水平,患者22个月无复发生存率分别为46.1%和92.9%,有显著统计学差异;放疗后复发、转移鼻咽癌患者血浆EBV/DNA的中位拷贝数显著高于治疗后持续缓解患者.结论:采用荧光定量PCR方法检测鼻咽癌患者血浆中游离的EBV/DNA是一种敏感可靠的方法,对于鼻咽癌早期诊断、鉴别诊断、分期、判断预后、监测治疗后复发和远处转移具有重要的临床意义,有可能成为鼻咽癌的血清肿瘤标记物.     

EB病毒抗体与鼻咽癌发病风险的前瞻性研究

[目的]探讨EB病毒抗体滴度变化与鼻咽癌发病风险的关系,为筛检高危人群提供依据.[方法] 1987～2007年对广东省四会市共18986名现场人群进行筛检,检测血清学EB病毒壳抗原免疫球蛋白(VCA/IgA)和早期抗原免疫球蛋白(EA/IgA)水平.采用Cox风险回归模型评估EB病毒抗体与鼻咽癌发病风险的关系.[结果] 1987～2007年共检出125例鼻咽癌.VCA/IgA和EA/IgA的血清阳性率分别为7.16％ (1318/18411)和0.24％ (45/18411).VCA/IgA阴性组鼻咽癌年龄调整发病率为29.4/10万人年,明显低于VCA/IgA阳性、EA/IgA阴性组(188.2/10万人年)和两者均阳性组(617.4/10万人年).与VCA/IgA阴性组相比,VCA/IgA阳性者抗体滴度越高,鼻咽癌发病风险越大.随访期间,EB病毒VCA/IgA抗体滴度升高者的鼻咽癌发病风险最高,在前5年的随访期间更为明显(调整HR=21.3,95％CI:7.1～64.1),抗体滴度降低者的发病风险最低(调整HR=1.5,95 ％CI:0.2～11.4).[结论]持续升高的VCA/IgA抗体滴度与鼻咽癌发病风险的增加明显相关,EB病毒VCA/IgA抗体阳性者是筛查的重点人群.     

鼻咽癌患者发病前后EB病毒VCA/IgA和EA/IgA滴度动态分析

目的 观察鼻咽癌患者发病前后EB病毒VCA/IgA、EA／IgA滴度的变化规律,及其在鼻咽癌筛查中的作用。方法 收集中山市首次鼻咽癌筛查后12年VCA／IgA阳性人群中54例新发鼻咽癌患者发病前后的血清学资料,用免疫酶法检测EB病毒抗体VCA/IgA和EA／IgA。结果 确诊前1～7年VCA／IgA、EA／IgA总体呈上升趋势。发病前7～4年,VCA／IgA平均滴度在1：21．04上下波动,确诊前第3年起VCA／IgA急剧上升,确诊时几何平均滴度接近1：80,EA／IgA高较为缓慢,确诊时几何平均滴度为1：6．49。放疗后两种滴度均呈快速下降趋势,第4年起接近阳性人群的平均滴度。结论 多数鼻咽癌患者在确诊前3年,VCA／IgA滴度持续增高,但EA／IgA滴度增高缓慢;VCA／IgA可以检出早期鼻咽癌,但EA／IgA作用不大;鼻咽癌发展临床前期平均时间为3年。     

血浆EBV DNA水平测定在监测鼻咽癌放疗后复发、转移中的临床意义

目的 探讨定量分析血浆EBV DNA水平在监测鼻咽癌复发、转移中的临床意义。方法 应用荧光定量PCR技术（real-time PCR）,检测360例根治放疗后鼻咽癌患者血浆EBV DNA水平,并与临床及影像学检查结果 比较。结果 360例患者中87例血浆EBV DNA检测阳性,273例阴性。在87例检出阳性者中,25例证实为临床复发,45例证实为远处转移,故其预测肿瘤进展阳性预测值为80%（70/87）。在273例血浆EBV DNA检测阴性患者中,共有17例复发和4例转移,故其阴性预测值为92%（252/273）。总计91例肿瘤进展患者中70例血浆EBV DNA阳性,其中复发42例,25例血浆EBV DNA阳性;转移49例,45例血浆EBVDNA阳性。269例临床缓解患者中17例血浆EBV DNA阳性,故其敏感性、特异性、假阳性率和假阴性率分别为77%（70/91）、94%（252/269）、6%（17/269）、23%（21/91）、90%（322/360）。复发患者、转移患者、肿瘤进展患者和临床缓解患者EBVDNA阳性率和中位拷贝数分别为：60%,4700 copies/ml;92%,425000 copies/ml;77%,38000 copies/ml;6%,〈500copies/ml。复发患者与转移患者比较、肿瘤进展患者与临床进展患者比较,血浆EBV DNA阳性率和中位拷贝数均有显著性差异。结论 血浆EBV DNA水平的检测是监测放疗后鼻咽癌患者转移、复发的有效指标。     

Significance of cell-free epstein-barr virus DNA in monitoring prognosis of nasopharyngeal carcinoma

Objective It has been reported that cell-free Epstein-Barr virus (EBV-DNA) in plasma was useful in diagnosing and monitoring nasopharyngeal carcinoma (NPC). The current study was designed to evaluate the significance of EBV-DNA in monitoring the prognosis of nasopharyngeal carcinoma and comparing its significance with that of plasma VCA/lgA and EA/lgA levels. Methods E8V -DNA, VCA/lgA, and EA/lgA levels in plasma were determined in NPC patients with different prognosis after radiotherapy, including 30 distant metastatic patients, 22 local recurrence patients and 24 individuals with remission who had been followed-up for more than 2 years after treatment. EBV-DNA was determined using a real-time quantitative PCR system, and levels of VCA/lgA and EA/lgA were measured using standard immunofluorescence. In a cohort study, the indexes were determined after different radiation periods for the 20 new cases of nasopharyngeal carcinoma. Results The median plasma EBV-DNA concentration was 135,100 copies/ ml (interquartile range: 5,525-1,003 750) in metastatic group, 20,500 copies/ ml (interquartile range: 0 -58,500) in the local recurrence group and 0 copies/ml (interquartile range: 0-0) in the continuous remission group (P< 0.05). The levels of VCA/lgA and EA/lgA showed no significant differences among the different groups. The high level of EBV-DNA concentration in the metastatic group was more than that in the local recurrence group. A level of 1,000,000 copies/ml of EBV DNA was an indication of distant metastasis of the NPC patients with a sensitivity of 27.3%. However, the sensitivity was 0 in the local recurrence group. For the 20 new patients, EBV -DNA concentration gradually decreased during the radiation period. Before radiation there were 32,050 copies/ml (interquartile range: 3,880-317,750), 0 copies/ml (interquartile range: 0-14 375) after a 40 Gy radiation dose and 0 copies/ml (interquartile range: 0-2940) after the radiation was finished (P< 0.05). However, the levels of VCA/lgA and EA/lgA showed no significant difference. Conclusion Determination of plasma cell -free EBV -DNA level is more valuable than evaluation of VCA/lgA and EA/lgA for monitoring the prognosis of NPC patients.     

Significance of Cell-Free Epstein-Barr Virus DNA in Monitoring Prognosis of Nasopharyngeal Carcinoma

Objective  It has been reported that cell-free Epstein-Barr virus (EBV-DNA) in plasma was useful in diagnosing and monitoring nasopharyngeal carcinoma (NPC). The current study was designed to evaluate the significance of EBV-DNA in monitoring the prognosis of nasopharyngeal carcinoma and comparing its significance with that of plasma VCA/lgA and EA/lgA levels. Methods  E8V -DNA, VCA/lgA, and EA/lgA levels in plasma were determined in NPC patients with different prognosis after radiotherapy, including 30 distant metastatic patients, 22 local recurrence patients and 24 individuals with remission who had been followed-up for more than 2 years after treatment. EBV-DNA was determined using a real-time quantitative PCR system, and levels of VCA/lgA and EA/lgA were measured using standard immunofluorescence. In a cohort study, the indexes were determined after different radiation periods for the 20 new cases of nasopharyngeal carcinoma. Results  The median plasma EBV-DNA concentration was 135,100 copies/ ml (interquartile range: 5,525-1,003 750) in metastatic group, 20,500 copies/ ml (interquartile range: 0 -58,500) in the local recurrence group and 0 copies/ml (interquartile range: 0-0) in the continuous remission group (P< 0.05). The levels of VCA/lgA and EA/lgA showed no significant differences among the different groups. The high level of EBV-DNA concentration in the metastatic group was more than that in the local recurrence group. A level of 1,000,000 copies/ml of EBV DNA was an indication of distant metastasis of the NPC patients with a sensitivity of 27.3%. However, the sensitivity was 0 in the local recurrence group. For the 20 new patients, EBV -DNA concentration gradually decreased during the radiation period. Before radiation there were 32,050 copies/ml (interquartile range: 3,880-317,750), 0 copies/ml (interquartile range: 0-14 375) after a 40 Gy radiation dose and 0 copies/ml (interquartile range: 0-2940) after the radiation was finished (P< 0.05). However, the levels of VCA/lgA and EA/lgA showed no significant difference. Conclusion  Determination of plasma cell -free EBV -DNA level is more valuable than evaluation of VCA/lgA and EA/lgA for monitoring the prognosis of NPC patients.     

Comparison of plasma Epstein-Barr virus (EBV) DNA levels and serum EBV immunoglobulin A/virus capsid antigen antibody titers in patients with nasopharyngeal carcinoma

BACKGROUND: Serologic measurement of antibodies to Epstein-Barr virus (EBV) immunoglobulin A/viral capsid antigen (IgA/VCA) and early antigen (IgA/EA) has been used widely to screen for nasopharyngeal carcinoma (NPC) in China. Recently, it was found that plasma EBV DNA concentration is an indicator for the staging and prognosis of patients with NPC. To determine whether there is a correlation between plasma EBV DNA levels and serum levels of IgA/VCA, the authors measured both in patients with NPC and in a control group. METHODS: Real-time polymerase chain reaction was used for quantitative analysis of plasma EBV DNA concentration, and enzyme-linked immunoadsorbent assay was used to measure EBV VCA/IgA in patients with primary NPC (n = 120 patients), locally recurrent NPC (n = 8 patients), and distant metastatic NPC (n = 21 patients) among 76 patients with NPC after the completion of radiotherapy, in 60 patients with NPC in clinical remission, in 38 patients with non-NPC tumors, and in 47 control individuals. RESULTS: The median plasma EBV DNA levels were 6200 copies/mL, 9200 copies/mL, and 2050 copies/mL in patients with primary, locally recurrent, and distant metastatic NPC, respectively, but declined to 0 copies/mL in patients with clinically remissive NPC, in patients who completed radiotherapy, in patients with non-NPC tumors, and in the control group. In contrast, EBV VCA/IgA titers and detection rates remained high in all NPC groups. Plasma EBV DNA levels were significantly higher in patients who had serum VCA/IgA titers > or = 1:640 (median, 83,450 copies/mL) compared with the levels in patients who had titers < or = 1:320 (median, 17,200 copies/mL). Patients with NPC who had advanced TNM stage (Stages III and IV; median, 8530 copies/mL) and T classification (T3 and T4 tumors; median, 8530 copies/mL) had significantly higher plasma EBV DNA levels compared with patients who had early TNM stage (Stages I and II; median, 930 copies/mL) and T classification (T1 and T2 tumors; median, 3700 copies). Patients who had advanced TNM stage NPC had significantly higher mean VCA/IgA titers (1:424) compared with patients who had early TNM stage NPC (1:246), but there was no correlation between IgA/VCA titer and T or N classification of NPC. CONCLUSIONS: The results suggest that plasma EBV DNA detection is a more sensitive and specific marker than the serum IgA/VCA titer for the diagnosis and monitoring of patients with NPC. These findings provide convincing evidence for the use of plasma EBV DNA measurements for the early diagnosis and staging of NPC as well as for monitoring recurrence and metastasis of this tumor.     

Molecular prognostication of nasopharyngeal carcinoma by quantitative analysis of circulating Epstein-Barr virus DNA

We investigated the prognostic implication of pretreatment plasma/serum EBV DNA concentration, as measured by real-time quantitative PCR, in nasopharyngeal carcinoma (NPC). In 91 prospectively recruited NPC patients, those with recurrence or metastasis within the first year after treatment had a higher median plasma EBV DNA concentration than those without events (41,756 copies/ml versus 5,807 copies/ml; P < 0.001, Mann-Whitney rank-sum test). In multivariate logistic regression analysis, plasma EBV DNA was an independent prognostic indicator for early clinical events [relative risk = 3.8 (95% confidence interval, 1.6-9.2 for each 10-fold increase in plasma EBV DNA concentration; P = 0.003)]. In a second cohort of 139 NPC patients followed-up for a median period of 2,027 days (interquartile range, 597-2,335 days), serum EBV DNA was found to be a significant variable associated with NPC-related death in multivariate Cox's regression analysis [relative risk = 1.6 (95% confidence interval, 1.1-2.1 for each 10-fold increase in serum EBV DNA concentration; P = 0.007)]. The quantitation of circulating EBV DNA may thus allow improved prognostication of NPC.     

Complementary serum test of antibodies to Epstein-Barr virus nuclear antigen-1 and early antigen: a possible alternative for primary screening of nasopharyngeal carcinoma

This hospital-based cohort study evaluated the efficacy of three Epstein-Barr virus (EBV) - associated assays for nasopharyngeal carcinoma (NPC) primary screening and monitoring treatment outcome. Five hundred and seventeen consecutive subjects, including 156 NPC patients, 264 healthy volunteers and 97 patients with head and neck squamous cell carcinoma (HNSCC) were enrolled. The sensitivity and specificity of EBV IgAs to viral capsid antigen (VCA), complementary EBV IgAs to early antigen and nuclear antigen-1 (EA+EBNA-1), and EBV DNA load were examined by immunofluorescent assays, enzyme-linked immunosorbent assays, and quantitative real-time PCR, respectively. After constructing the receiver operating characteristics to demonstrate screening efficacy, EBV EA+EBNA-1 IgA (AUC: 0.952; 95% CI, 0.930-0.974) was proved superior to EBV VCA IgA (AUC: 0.888; 95% CI, 0.854-0.922) or EBV DNA load (AUC: 0.893; 95% CI, 0.854-0.932) in differentiating NPC patients from controls. Comparison of screening efficacy between NPC patients and HNSCC patients revealed EBV EA+EBNA-1 IgA (AUC: 0.964; 95% CI, 0.943-0.985) still outperformed EBV VCA IgA (AUC: 0.884; 95% CI, 0.845-0.923). In subjects with higher serum titer or level equal to or above 1:80 and 6 EU/ml for EBV VCA IgA and EA+EBNA-1 IgA, the specificity reached as high as 99.2% and 95.1%, respectively, in the control groups. However, correlation of these three assays with clinicopathological manifestations of NPC, revealed only EBV DNA load significantly associated with N stage and overall stage in NPC patients. Additionally, EBV DNA load could be used to further raise the specificity of EBV EA+EBNA-1 IgA assays and was also the only assay to be consistently predictive of tumor relapse in post-treatment patients according to serial test results by time frame. Consequently, an EBV EA+EBNA-1 IgA-based protocol is recommended for mass screening, but EBV DNA load should be used solely for post-treatment monitoring for NPC in endemic areas.     

Prognostic value of serum Epstein–Barr virus antibodies in patients with nasopharyngeal carcinoma and undetectable pretreatment Epstein–Barr virus DNA

Epstein–Barr virus (EBV) is closely associated with nasopharyngeal carcinoma (NPC). Serum IgA antibodies against early antigen (EA‐IgA) and viral capsid antigen (VCA‐IgA) are the most commonly used to screen for NPC in endemic areas. However, the prognostic value of serum EA‐IgA and VCA‐IgA in patients with NPC is less clear. We hypothesize that serum EA‐IgA and VCA‐IgA levels have prognostic impact for survival outcomes in NPC patients with undetectable pretreatment EBV (pEBV) DNA. In this series, 334 patients with non‐metastatic NPC and undetectable pEBV DNA were included. Serum EA‐IgA and VCA‐IgA were determined by ELISA. After analysis, serum EA‐IgA and VCA‐IgA loads correlated positively with T, N, and overall stage (all P < 0.05). Serum EA‐IgA was not associated with survival outcome in univariable analyses. But patients with serum VCA‐IgA >1:120 had significantly inferior 5‐year progression‐free survival (80.4% vs 89.6%, P = 0.025), distant metastasis‐free survival (88.4% vs 94.8%, P = 0.050), and locoregional relapse‐free survival (88.4% vs 95.6%, P = 0.023; log–rank test). Multivariable analyses revealed that N stage was the only independent prognostic factor (all P < 0.05), but the VCA‐IgA became insignificant. Further analyses revealed that serum VCA‐IgA was not an independent prognostic factor in early N (N0–1) or advanced N (N2–3) stage NPC. In summary, although both EA‐IgA and VCA‐IgA correlate strongly with TNM stage, our analyses do not suggest that these antibodies are prognostic biomarkers in patients with NPC and undetectable pEBV DNA.     

Significance of Plasma IgA and IgG Antibodies to Epstein-Barr Virus Early and Viral Capsid Antigens in Thai Nasopharyngeal Carcinoma

Epstein-Barr virus (EBV) is an important causal factor of human nasopharyngeal carcinoma (NPC). High levels ‍of serum IgA and IgG antibodies to EBV early and viral capsid antigens (IgA/EA, IgA/VCA, IgG/EA and IgG/VCA) ‍have been reported in NPC patients. Since specific serum IgA/EA, IgA/VCA and IgG/EA are claimed to be useful ‍serological markers for NPC. In order to evaluate whether plasma IgA/EA, IgA/VCA, IgG/EA and IgG/VCA antibody ‍levels are useful markers for diagnosis and prognosis of Thai NPC, we examined the prevalence of these antibodies ‍in 79 NPC patients, and 127 age-matched controls (47 healthy subjects (HS), 32 cases of other disease (OD) and 48 ‍cases of other cancer (OC)) by using an indirect immunofluorescence assay. The prevalence of plasma IgA/EA, IgA/ ‍VCA, and IgG/EA in NPC patients (55.7, 68.4 and 68.4%) was significantly higher than in the HS (0.0, 0.0 and ‍20.5%,), OD (0.0, 0.0 and 3.1%) and OC (0.0, 0.0 and 20.8%) groups (p<0.05). The prevalence of plasma IgG/VCA ‍in NPC patients (93.7%) was significantly different from those for the OD and OC groups (71.9 and 43.8%) but not ‍for the HS group (89.4%). In NPC patients, the geometric mean titers (GMT) of plasma IgA/EA, IgA/VCA and IgG/ ‍EA were increased with an advanced clinical stage of disease but not IgG/VCA. In contrast, GMT of IgG/VCA was ‍increased with aggressive type of disease (histological type) but not IgA/EA, IgA/VCA, and IgG/VCA. The results of ‍our study suggest that plasma IgA/EA, IgA/VCA and IgG/EA antibodies may be useful markers for diagnosis and ‍assessing prognosis of Thai NPC. ‍