[Investigation of EB virus DNA BamHI W fragment, EBNA-2 types and EBNA expression in benign and malignant nasopharyngeal biopsies].

Nasopharyngeal biopsies from 96 cases of clinically suspected nasopharyngeal carcinoma and chronic nasopharyngitis were investigated using EB virus DNA BamHI W fragment and EBNA-2 A, B type probes. There was a significant dominance of EBV EBNA-2 A type infection on all samples: nasopharyngeal carcinoma (NPC) 27/35 (77.1%), clinically suspected NPC 7/10 (70.0%), chronic nasopharyngitis (CNP) 18/27 (66.7%). Both W and A probes positive were 20/29 (69.0%) in NPC and 8/25 (32.0%) in non-NPC, indicating a close relationship between the infection of EBNA-2 A type virus and NPC in this series. Meanwhile, the expression of EBNA on 35 cases of biopsy were detected using the anti-complement immunofluorescence method, 19/20 (95.0%) were positive in the NPC group and 1/15 (6.7%) in the non-NPC group. Based on the positive results in detection of A, W or EBNA expression, there was a significant difference between NPC and non-NPC groups (P < 0.001). It is suggested that EBV infection, especially type A, plays an important role in the etiology and pathogenesis of NPC in the Zhanjiang area.