T lymphocyte subsets and platelet-associated IgG in idiopathic thrombocytopenic purpura: effect of splenectomy.

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-gamma-bearing T lymphocytes (T-gamma). Patients 'cured' by splenectomy (12 out of 17) showed a normal PAIgG level, a marked increase of T-gamma cells and a reduction of T-mu cells; patients 'not cured' by splenectomy showed an increased PAIgG level and a reduction of T-gamma cells. An increase of PAIgG levels and a reduction of T-gamma cells were found in 2 splenectomized patients after relapse. An association between chronic nonresponsive ITP and decrease of T-gamma cells was established.