A comparison of fresh and cultured T lymphocytes from patients with ataxia telangiectasia using T‐cell subset markers and chromosome translocations

Ataxia telangiectasia (A‐T) is an autosomal recessive disorder in which patients show an unusual predisposition to lymphoid malignancies including T‐cell leukaemia. We compare here the surface phenotypes of fresh and cultured A‐T T cells. A total of 17 T‐cell cultures from 8 A‐T patients are compared with each other and with 5 T‐cell cultures from normal individuals. The large, cytogenetically abnormal t(14;14) and t(X;14) clones in 2 of the patients both occurred only in the CD8 + population of T lymphocytes. There was no difference in the rate of growth of A‐T T cells in vitro compared with those from normal individuals, although many of the original characteristics of the T cells were lost, including the cytogenetically abnormal clones seen in fresh A‐T lymphocytes.