THE BCL-2 JH GENE REARRANGEMENT IS UNDETECTABLE IN HODGKINS LYMPHOMAS- RESULTS FROM THE GERMAN HODGKIN TRIAL/

Ninety-one Hodgkin's lymphomas (HD), 52 non-Hodgkin lymphomas (NHL) an d 33 specimens of non-neoplastic lymphatic tissues were investigated b y polymerase chain reaction (PCR) for the presence of the bcl-2/JH gen e rearrangement. The majority of the HD cases were drawn from the file s of the German Hodgkin trial where diagnoses are established by a pan el of four independent histopathologists. Using the very sensitive PCR method which detected 1 positive among 10000 negative cells, the bcl- 2/JH gene rearrangement was found in 7/52 NHL and 3/16 tonsils with fo llicular hyperplasia, but in none of the 91 HD. The bcl-2 protein, how ever, was expressed by malignant cells of B and T cell lymphomas and b y the giant tumour cells in 2/13 HD lymphocyte predominant, 11/28 HD n odular sclerosing I, 14/17 HD nodular sclerosing II, 10/27 HD mixed ce llularity and 3/3 HD lymphocyte depleted. The bcl-2/JH rearrangement i s thus independent of protein over-expression, the latter being found in all types of lymphomas. Our results do not confirm the findings of others who have detected the bcl-2/JH rearrangement in HD. These discr epancies may be explained by differences in choice of material, the ge ne rearrangement actually occuring in bystander cells but not in Reed- Sternberg or Hodgkin cells, or by contamination.