DETECTION OF EPSTEIN-BARR-VIRUS RNA AND RELATED ANTIGENS IN NONNEOPLASTIC LYMPHOID LESIONS

To elucidate the latent state and reactivation of Epstein-Barr virus ( EBV) in non-neoplastic lymphoid lesions, we investigated 144 nonneopla stic lymphoid lesions by in situ hybridization (ISH) to detect the exp ression of EBV-encoded small RNAs (EBER)-1 and BCRF-1 and by immunosta ining for latent membrane protein (LMP)-1 and ZEBRA. ISH for EBER-1 de tected EBER-1 1-positive cells (EPC) in 31 of the 144 examined lesions (22%). EPC were detected in 4 of 49 cases of nonspecific lymphoid hyp erplasia, in 16 of 20 abscess-forming granulomatous lymphadenitis (AFG L), 5 of 25 Kikuchi's disease, and in 3 of 3 infectious mononucleosis. LMP-1 was expressed in 6 of 124 non-neoplastic lymphoid lesions (4.8% ). LMP-1-positive cells were observed in 6 of the 31 EBER-1-positive c ases (19%). EPC were detected significantly more frequently in LMP-1- and ZEBRA-positive specimens than in the LMP-1- and ZEBRA-negative spe cimens. BCRF-1 was expressed in 4 of 11 cases examined: 2 of 3 AFGL, 1 of 2 Kikuchi's disease, and in the 1 case of atypical lymphoid hyperp lasia. This study suggests that Epstein-Barr virus is prevalent and ca n be reactivated in the lymph nodes effaced by destructive inflammatio n, such as AFGL. Such inflammation may provide a local milieu that is conducive for EBV to enter the lyric cycle.