HIGH EXPRESSION OF THE BCL-X GENE IN REED-STERNBERG CELLS OF HODGKINS-DISEASE

The expression of bcl-x protein, a bcl-2-related protein present in co rtical thymocytes, activated lymphocytes, and plasma cells of reactive lymph nodes, was investigated in 44 cases of Hodgkin's disease (HD) i n parallel with bcl-2 and Epstein-Barr virus (EBV) status. Eighty-six percent of the cases were positive for bcl-x, among them 27% with a st rong signal in more than 75% of the Reed-Sternberg cells. Positivity f or bcl-x was found in, respectively, 100% and 92% of the nodular scler osis and mixed cellularity subtypes, although 4 cases of lymphocyte pr edominance subtype were negative. This finding was in contrast with th e weaker positivity for bcl-2 staining in 44% of the cases. EBV small RNAs were detected in 43% of the cases by using in situ hybridization. Of interest, 100% of the EBV-positive samples were positive for bcl-x , whereas only 38% of these cases were bcl-2 positive, Our findings sh ow that the bcl-x gene expression is high in HD, suggesting that bcl-x may have a role in the pathogenesis of at least some cases of HD via apoptosis regulation. (C) 1995 by The American Society of Hematology.