AUTOREACTIVE T-CELL-DEPENDENT POLYCLONAL HYPERGAMMAGLOBULINEMIA IN MANTLE CELL LYMPHOMA

We investigated the mechanism of polyclonal B cell differentiation in mantle cell lymphoma (MCL) using peripheral blood mononuclear cells (P BMC) from a patient with MCL in leukemic stage presenting polyclonal h ypergammaglobulinemia. Patient T cells not only responded to autologou s non-T cells but induced polyclonal production of IgG in vitro. Flow cytometric analysis of PBMC showed the increased conversion of CD4+ T cells from the naive to the memory state. We propose the possible mech anism that autoreactive T cells may be involved in polyclonal B cell d ifferentiation in this monoclonal B cell disorder.