Abstract
The modifications of cell-mediated immunity in idiopathic thrombocytopenic purpura (ITP) were investigated using the technique of Moretta et al. [J. exp. Med. 151: 969–974, 1980] to study T lymphocyte subsets in 35 ITP subjects at various clinical stages. In all these patients, platelet-associated IgG (PAIgG) were measured by a complement lysis inhibition technique. Untreated ITP patients did not show significant modifications of T lymphocyte subsets. Patients with thrombocytopenia not responsive to corticoids or splenectomy and increased PAIgG levels showed significant reduction of Fc-γ-bearing T lymphocytes (T- γ). Patients ‘cured’ by splenectomy (12 out of 17) showed a normal PAIgG level, a marked increase of T-γcells and a reduction of T-μ cells; patients ‘not cured’ by splenectomy showed an increased PAIgG level and a reduction of T- γcells. An increase of PAIgG levels and a reduction of T- γcells were found in 2 splenectomized patients after relapse. An association between chronic nonresponsive ITP and decrease of T- γcells was established.