Linear epitopes of the replication-activator protein of Epstein-Barr virus recognised by specific serum IgG in nasopharyngeal carcinoma

Serum Zta antibody of Epstein-Barr virus exerts potential function in the diagnosis of nasopharyngeal cancer

The diagnosis of nasopharyngeal cancer (NPC) remains a clinical challenge. Many studies have assessed the diagnostic potential of Zta antibody of the Epstein-Barr virus (EBV) in NPC patients but with controversial results. This study aims to summarize the overall diagnostic performance of EBV Zta antibody in NPC. Based on a comprehensive search of the Pubmed and Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI), Wanfang Databases and China Citation Databases, we identified outcome data from all articles estimating diagnostic accuracy of EBV Zta antibody for NPC. A summary estimation for sensitivity, specificity, and other diagnostic indexes were pooled using a bivariate model. The overall measure of accuracy was calculated using summary receiver operating characteristic curve and the area under curve (AUC) was calculated. According to our inclusion criteria, 17 studies with 11,822 subjects (1,645 NPC cases, 10,177 controls) were included. The summary estimates were: sensitivity 0.87 (95 % confidence interval [CI] = 0.86-0.89), specificity 0.94 (95 % CI = 0.93-0.94), positive likelihood ratio 8.05 (95 % CI = 5.59-11.59), negative likelihood ratio 0.16 (95 % CI = 0.12-0.21), diagnostic odds ratio 52.93 (95 % CI = 29.95-93.56), the AUC and Q* index were 0.9352 and 0.8714, respectively. In conclusion, serum EBV Zta had a better diagnostic performance for NPC. Further studies should be performed to confirm our findings.

High Epstein-Barr virus serum load and elevated titers of anti-ZEBRA antibodies in patients with EBV-harboring tumor cells of Hodgkin's disease

Hodgkin's disease is commonly associated with EBV latent infection. The incidence of EBV reactivation (active infection or EBV infection with replicative cycle) was evaluated in a series of 30 patients with untreated Hodgkin's disease (except for one case with chronic lymphocytic leukemia) by quantitation of EBV DNA and titration of anti-ZEBRA antibodies in serum samples. DNA was detected in serum (>2.5 x 10(2) genomes/ml) in 15 of 30 patients and was more frequent in Hodgkin's disease with EBV-positive Reed-Sternberg cells (10/12) than in EBV-negative cases (5/18), (P< 0.01). Of interest was the demonstration that viremia correlated well with increased titers of anti-ZEBRA IgG and/or standard serological profiles of EBV reactivation (12/15), (P < 0.05). However the lack of EBV replicative cycle in Reed-Sternberg cells (negative for ZEBRA antigen and early antigen BHLF1) suggests that the viral replication occurs in a nonneoplastic cell compartment rather than in tumor cells. The measurement of EBV DNA loads and the titration of anti-ZEBRA antibodies shed new lights on the link between activation of EBV replication and Hodgkin's disease: these serological markers together with the determination of the EBV status of the tumor suggest that replication of the viral genome occurs with a decreased efficiency of the immune system, thus allowing progression of the tumor.