Geographical aspects of bcl-2 gene involvement in Japanese patients with non-Hodgkin's B-cell lymphomas.

Using three separate bcl-2 probes, we examined involvement of the bcl-2 gene in Japanese patients with non-Hodgkin's B-cell lymphomas. Of 52 patients with follicular lymphoma (FL), 24 had rearrangements. In a group of 50 patients with diffuse lymphoma, three of 32 patients with diffuse large cell lymphoma had rearrangements. The frequency of rearrangements in each of these groups, as detected by both major and minor breakpoint cluster region probes, was compatible with that found in other Far Eastern studies. However, the difference in frequency between the groups studied in the Far East and the West was significant, and these two geographically distinct populations also displayed a difference in the breakpoint distribution. In the immunophenotype study of 33 patients with FL, the expression of CD10 antigen correlated with bcl-2 involvement, whereas none of the other B markers emerged as parameters to distinguish between the two lymphoma groups; those with, and without, the rearrangements.