[bcl-2 gene involved in Japanese follicular lymphoma].

Using three chromosome 18-specific DNAs, rearrangements of a bcl-2 gene were detected in 20 (44%) of 45 Japanese patients (pts) with follicular lymphoma (FL) and 3 (8%) of 36 pts with diffuse large cell lymphoma. The 21 pts had t (IgH; bcl-2), and of the remaining two who did not display it, one had chromosome t(14; 18). Compared with the findings in American pts, the lower frequency of t(14; 18)-positive lymphoma could reflect a difference in the incidence of overall nodal B lymphoma between Japan and the United States. 11 of 18 pts with t(14; 18)-positive FL expressed CD10 antigen on the cell surface and all 12 pts with t(14; 18)-negative FL did not, and the difference is statistically significant, indicating that t(14; 18)-positive Japanese FL is the same disease entity as most of American FL. Extra 18q- chromosome found in the advanced grade diseases of t(14; 18)-positive lymphoma results in amplification of the rearranged bcl-2 gene on 18q-, suggesting that the change is closely associated with transformation of FL carrying t(14; 18). It is thus possible of international realization to institute the prognostic factors and the treatment strategy for conquering t(14; 18)-positive lymphoma.