Comparison of alpha beta and gamma delta expressing CD3+ acute lymphoblastic leukemias.

Analysis of 267 consecutive cases of acute lymphoblastic leukemias (ALL) showed that 67 (25%) of cases were of T cell lineage and that 21/67 (31%) expressed the CD3 antigen. Of 13 CD3+ T-ALLs, 7 expressed gamma delta and 6 alpha beta. Comparison of these 2 groups showed differences in clinical and immunophenotypic parameters. The patterns of rearrangement of TCR gamma and TCR delta genes and their junctional nucleotide sequences also differed between the 2 groups. Further analysis of these patients may allow the distinction of subpopulations of ALL which merit altered management.