Contrasuppressor T cell leukaemia: clonal proliferation of contrasuppressor T cells in a patient with granular lymphocyte-proliferative disorder.

Summary In 12 patients with granular lymphocyte-proliferative disorders (GLPD), we studied the capacity of patient peripheral blood mononuclear cells (PBMC) to promote or suppress polyclonal IgG synthesis by normal non-T cells in pokeweed mitogen-containing medium using an enzymelinked immunosorbent assay. During the experiments we found a patient whose PBMC possessed contrasuppressor function. The patient was a 27-year-old female with anaemia and lymphocytosis of CD3+CD8+ granular lymphocytes (GL). Reconstitution experiments using normal donor non-T cells and CD4+ and CD8+ T cells showed that addition of the patient's CD8+ cells abrogated the suppressor cell function of normal CD8+ T cells. The patient's PBMCs were CD3+, CD8+, Ia+, and Vicia villosa lectin-adherent characteristics which are consistent with those of normal blood contrasuppressor T cells. The T cell receptor β and γ genes were found to be monoclonally rearranged. Ultrastructurally, this patient's GLs exhibited clusters of dense cytoplasmic bodies, which were not detected in the GL of other patients with GLPDs. These results indicate that the clonal proliferation of contrasuppressor T lymphocytes had occurred in this patient.