Analysis of EB virus LMP2 specific immune status among three groups in Guangxi area

Objective To investigate the difference of EB-LMP2 specific immune status among patients with nasopharyngeal carcinoma, serum EBV VCA/IgA positive group and EBV VCA/IgA negative group in Guangxi area of china. Methods 60 cases of serum EBV VCA/IgA screening positive volunteers and 20 cases of negative volunteers came from Cangwu county in Guangxi area, and 134 cases of patients volunteers with nasopharyngeal carcinoma (NPC) came from The People's Hospital of Guangxi Zhuang Autonomous Region. Blood samples were taken before any treatment, and the preipheral blood mononuclear cels(PBMC) were taken by Ficoll density gradient centrifugation.Specific immune responses of cytotoxic T lymphocytes (CTLs) were measured using IFN-γ ELISPOT assays with HLA-matched LMP2 epitope peptides. Results LMP2 specific immune responses levels in nasopharyngeal carcinoma patients were significantly lower than those healthy volunteers and serum EBV VCA/IgA screening positive volunteers (P<0.01), and the immune responses were statistically different in three VCA/IgA titers (1∶5, 1∶10 and 1∶20 or more, P=0.002); LMP2 specific immune responses in early stage patients of nasopharyngeal carcinoma (stage I/II) were better than those advanced stage (stage Ⅲ and stage IV) (P<0.01). Conclusions The difference of LMP2 specific CTL levels among three groups may be the important reason for the long-term latent infection of EB virus and lead to the occurrence of nasopharyngeal carcinoma, and LMP2 specific immunotherapy is expected to reduce the incidence of nasopharyngeal carcinoma. Key words: Nasopharyngeal carcinoma(NPC); EB virus; LMP2; ELISPOT; cytotoxic lymphocyte, CTL, immunotherapy