Depressed functional and phenotypic properties of T but not B lymphocytes
in idiopathic thrombocytopenic purpura
R Mylvaganam, RO Garcia, YS Ahn, PG Sprinz, CI Kim and WJ Harrington
Department of Medicine, University of Miami School of Medicine, FL 33101.
Chronic idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder
in which the abnormality in cellular immunity has remained only vaguely
defined. Previously we have shown that patients with ITP in its active
phase have abnormal T cell subsets. We then examined the phenotypes of T
and B lymphocytes in an additional 28 patients with ITP and 32 age- and
sex-matched normal controls and compared the lymphocytes' capacity to
respond to polyclonal T, T cell-dependent B, and B cell mitogens.
Blastogenesis to optimal (5.0 micrograms/mL) and suboptimal (0.5
microgram/mL) concentrations of the polyclonal T cell mitogens were
markedly depressed in patients compared with normal controls (P less than
.0005). Similarly, a severe depression in response was noted with the
polyclonal T cell-dependent B cell mitogen (P less than .000001). No
difference was seen, however, with the polyclonal B cell mitogen. The
proportions of pan-T and T helper/inducer lymphocytes were significantly
depressed (P less than .005 and P less than .000005 respectively), and the
T suppressor/cytotoxic lymphocytes increased (P less than .02) in patients
relative to controls. But there was no difference in the proportion of B
lymphocytes or in their functional response. The abnormal cellular immunity
appears to be due to a defect in the T lymphocyte population without
involvement of the B lymphocytes.
Volume 71,
Issue 5,
pp. 1455-1460,
05/01/1988
Copyright © 1988 by The American Society of Hematology
