T-CELL RECEPTOR GENE REARRANGEMENTS IN LYMPHOID AND NONLYMPHOID LEUKEMIAS

Rearrangements of delta-, tau-, and beta- T-cell receptor (TcR) chain genes were analysed in 64 haematologic malignancies comprising T- and B-lineage acute lymphoblastic leukaemias (ALL), B-chronic lymphocytic leukaemias (CLL), acute myeloid leukaemias (AML) and acute undifferent iated leukaemias (AUL). The TcR genes were rearranged in 5/6 TALL. In non-T-leukaemias the frequency of TcR gene rearrangements was higher i n B-lineage ALL (8/11), although they were air detected in B-CLL (5/29 ), AML (1/16) and AUL (2/4). Immunoglobulin (Ig) gene rearrangements w ere observed in 1/6 T-ALL and 2/14 AML. The analysis of these gene con figurations has a diagnostic application since it allows the definitio n of the clonality of malignant proliferation and although they are no t lineage specific such configurations represent a further parameter t o evaluate, together with the immunophenotype and morphology, in the a ssignment or exclusion of the differentiation lineage of the haematolo gic malignancies.