HODGKINS-DISEASE BIOLOGY - RECENT ADVANCES

The cellular origin of H-RS cells has been questioned for a long time. Recently, using single cell amplification of Ig genes evidence was ob tained that H-RS cells clonally arise from B-cells. Sequence analysis of rearranged Ig genes demonstrated that H-RS cells develop within the germinal centre. H-RS cells in classical KD grow despite loss of func tion of their rearranged Ig genes. In contrast, the mutation pattern o f rearranged Ig genes in L & H cells of lymphocyte-predominant HD freq uently shows ongoing mutations indicating that these cell are still an tigen selected. These molecular differences show that LP HD geneticall y differs from classical HD. H-RS cells escape from apoptosis within t he germinal centre. However, the events leading to malignant transform ation are still unknown. The association between EBV and HD has been r epeatedly described, but the occurrence of EBV negative cases is hard to explain just by loss of EBV. The analysis of chromosomal aberration s in H-RS cells did not result in the description of a specific 'HD-ge ne'. Also the role of the T-lymphocytes surrounding the H-RS cells has remained an open question. (C) 1997 John Wiley & Sons, Ltd.