Epstein-Barr virus infection in nasopharyngeal lymphoid hyperplasia

Objective To detect whether Epstein-Barr virus (EBV) harbors in nasopharyng eal lymphoid hyperplasia (NPLH) which is frequently to be seen in Guangzhou , a high-incidence area of nasopharyngeal carcinoma (NPC), and to explore t he relation between NPLH and development of NPC. Methods Twenty-four 10% formalin-fixed, paraffin-embedded biopsies oef pati ents with NPLH and elevated serum IgA antibody titer (greater than or equal to 1 :20) against viral capsid antigen of EB virus (IGA/VCA) were collecte d from the archives of the Department of Pathology, Sun Yat-sen University of Medical Sciences during the period of January to June, 1993. PGR plus So uthern blotting hybridization for detection of EBV DNA VV-fragment and in s itu hybridization for detection of EB virus encoded small RNAs (EBERs) were performed. All the patients were followed up more than 5 years. Results Twenty-two of 24 (91.7%) NPLH tissues contained EBV DNA. A few defi nitely EBERs positive B-lymphocytes could be found in 17 out of 24 specimen s (70.8%). Neither NPC nor any EBV-associated malignancies were developed i n all of these 24 patients up to date. Conclusion Most of the NPLH tissues taken from the patients with an elevate d serum IgA/VCA titer carry EBV, which is harbouring in the nuclei of a few infiltrating and hyperplastic B-lymphocytes. The NPLH without epithelial d ysplasia can not be recognized as a precancerous lesion, and EBV infection in these lesions is not an important event, having no substantial significa nce in development of NPC.