TCR/CD4 Large Granular Lymphocytosis A New Clonal T-Cell Lymphoproliferative Disorder

Large granular lymphocyte (LGL) leukemia is a well-recognized disease of mature T-CD8 or less fre-quently natural killer cells; in contrast, monoclonal expansions of CD4 T-LGL have only been sporadi-cally reported in the literature. In the present article we have explored throughout a period of 56 months the incidence of monoclonal expansions of CD4 T-LGL in a population of 2.2 million inhabitants and analyzed the immunophenotype and the pattern of cytokine production of clonal CD4 T cells of a series of 34 consecutive cases. Like CD8 T-LGL leukemias, CD4 T-LGL leukemia patients have an indolent dis-ease; however, in contrast to CD8 T-LGL leukemias, they do not show cytopenias and autoimmune phe-nomena and they frequently have associated neo-plasias, which is usually determining the clinical course of the disease. Monoclonal CD4 T-LGL showed expression of TCR , variable levels of CD8 (CD8/dim) and a homogeneous typical cytotoxic (granzyme B, CD56, CD57, CD11b/) and acti-vated/memory T cell (CD2bright, CD7/dim