Defective T cell responsiveness in chronic lymphocytic leukemia: analysis
of activation events
NE Kay and ME Kaplan
Chronic lymphocytic leukemia (CLL) is a B cell disorder in which major T
cell proliferative defects are present. We investigated the nature of this
deficit by studying several parameters known to be crucial in normal T cell
proliferative response to mitogen. Purified peripheral blood T cells from
B-CLL patients were analyzed for the presence of T3 antigen. We observed
that CLL T cells have a direct correlation between levels of T3 membrane
antigen and proliferative response to mitogen. The appearance of activation
antigens (transferrin, HLA-DR, and interleukin 2 [IL 2] receptor) was
normal in CLL T cells post-mitogen exposure. Despite the normal
presentation of IL 2 receptor on CLL T cell membrane, there was decreased
production of IL 2 by CLL patients (v controls) (39.6 +/- 10.2 cells per
milliliter v 64.6 +/- 11.0 cells per milliliter). Finally, we were able
partially, but not fully, to reconstitute CLL T proliferative response to
mitogen by adding purified exogenous IL 2. These findings suggest that CLL
T cells have multiple defects that may impact on their proliferative
potential. Further insight into these deficits may result in strategies
that will facilitate immunologic restoration in T cells of these patients.
Volume 67,
Issue 3,
pp. 578-581,
03/01/1986
Copyright © 1986 by The American Society of Hematology
