T cell receptor delta gene rearrangements occur predominantly in immature myeloid leukemias exhibiting lineage promiscuity

Abstract

T cell receptor delta (TCR) genes have been recently identified as rearranging during the early stages of T cell differentiation. We have analyzed the configuration of these genes in 47 unselected acute nonlymphoid leukemias. Morphology, phenotype, immunoglobulin heavy chain, and T cell receptor beta and gamma chain gene configuration were also studied. We have documented TCR delta gene rearrangements or deletions in eight cases using a genomic J delta 1 probe. The comparison of morphological, phenotypical, and molecular findings from these cases with those from control acute myeloid leukemias whose TCR delta genes were in germline configuration show that TCR delta rearrangements occur predominantly in immature leukemia exhibiting extensive lineage infidelity. The most striking feature was the frequent expression of the CD10 antigen. These data show that inappropriate gene rearrangements occur nonrandomly in myeloid leukemias and suggest that common mechanisms may be involved in the regulation of gene rearrangements and in the expression of some differentiation antigens.