THE IMPACT OF EBV, PROLIFERATION RATE, AND BCL-2 EXPRESSION IN HODGKINS-DISEASE IN CHILDHOOD

The role of Epstein-Barr virus (EBV) in the pathogenesis of Hodgkin's disease (HD) has not yet been clarified. Using RNA in situ hybridizati on (ISH) and immunohistochemistry (IHC), the occurrence of small Epste in-Barr virus encoded RNA (EBER) and latent membrane protein-1 (LMP-1) was studied in 22 tissue samples from 21 patients between 4 and 17 ye ars of age with Hodgkin's disease. EBER was detected in eight of 21 pa tients (38%) in Hodgkin and Reed-Sternberg cells and reactive lymphocy tes irrespective of initial clinical stage and histological subtype, w hereas LMP-1, positive in ten of 21 patients (48%), was restricted to neoplastic cells. All cases positive for EBER expressed LMP-1 as well. Additionally, oncoprotein Bcl-2 was identified in nine of 21 patients (43%), indicating, besides immortalization of HD cells by EBV, a furt her growth advantage due to apoptosis prevention by overexpression of this protein. Proliferation-associated antigens Ki-S1 and Ki-S5 were h ighly expressed in Hodgkin and Reed-Sternberg cells. CD 30 antigen was found in most cases, using two different antibodies (90% and 80%). Th e presence of this protein, which belongs to the family of nerve growt h factor receptor (NGFR), is related to high expression of Ki-67 prote in, detected by Ki-S5. CD 20 antigen was detectable in only three of 2 1 patients (14%). If we compare results of ISH and IHC with clinical d ata, the occurrence of EBV genome in children with HD seems to have no adverse effect on the final outcome of these patients.