Epstein-Barr Virus in Korean Malignant Lymphomas

ABSTRACT

To determine the prevalence of Epstein-Barr virus infection in lymphoid neoplasms of various histology and location, the paraffin tissues of 74 non-Hodgkin's lymphomas and 13 Hodgkin's diseases were studied by EBER and BHLF RNA in situ hybridization as well as immunostaining using LMP-1, EBNA-2, and ZEBRA. As a control, non-neoplastic lymphoid tissues from the nasal cavity(10), lymph node(38) and Waldeyer's ring(12) were investigated. In non-neoplastic control, EBV genome was detected in none of 10 nasal mucosa, 6 of 38 lymph node, and 1 of 12 Waldeyer's ring. EBV-positive non-neoplastic lymphocytes expressed CD45RO in 2 cases and CD20 in 4 cases. Non-Hodgkin's lymphoma was positive for EBV in 37.8% of the cases in which T-cell lymphoma showed higher rate(56%) than B-cell lymphoma(15%), especially in nasal lymphoma(80%) and angiocentric lymphoma(63.6%). Hodgkin's disease was EBV positive in 38.4% of the cases. EBV genome in tumor tissue existed in latent form as well as in lytic form. LMP-1 was positive in 80% of Hodgkin's disease and 39% of non-Hodgkin's lymphoma in which EBV genome was detected. EBNA-2 was expressed in 3 cases of non-Hodgkin's lymphoma. On the basis of protein expression, most lymphomas belonged to type II latency. These results support that EBV is associated with pathogenesis of malignant lymphoma although its mechanism still awaits to be clarified.