concanavalin-a and Cryoglobulinemia

Peripheral blood mononuclear cells from patients with essential mixed cryoglobulinemia (EMC) were studied for their ability to differentiate into cells containing cytoplasmic immunoglobulins (Ig) and to synthetize Ig after in vitro pokeweed mitogen activation. EMC lymphocytes showed a significant defective differentiation and Ig synthesis compared to normal controls. Coculture experiments carried out mixing enriched normal T- and EMC B-cell suspensions, and vice versa, showed that (a) the EMC B-cell-defective Ig synthesis still persisted after removal of suppressor activity by irradiation, both with autologous and with normal allogeneic T suspensions and (b) EMC T cells displayed a less efficient activity in helping Ig production by normal B lymphocytes. A comparable, reduced response was also found after activation with Staphylococcus aureus strain Cowan I. Taken together these results seem to indicate that in essential mixed cryoglobulinemia an impaired T-cell helper activity coexists with a B-lymphocyte impairment. The significance of these abnormalities in the pathogenesis of EMC is discussed.

Topics: Adult; Aged; Antibodies, Monoclonal; B-Lymphocytes; Concanavalin A; Cryoglobulinemia; Female; Humans; Immunoglobulins; Lymphocyte Activation; Lymphocyte Culture Test, Mixed; Male; Middle Aged; Pokeweed Mitogens; Staphylococcus aureus; T-Lymphocytes

Peripheral blood mononuclear cells from patients with essential mixed cryoglobulinemia were investigated for the ability to induce suppressor cell activity (S.C.A.) following in vitro exposure to Concanavalin A (Con A). The generation of Con A-S.C.A. is significantly impaired in essential mixed cryoglobulinemia compared to the healthy controls. No correlation was found between Con A-S.C.A. and the clinical or laboratory parameters of the disease. This impaired ability to induce Con A-S.C.A. in essential mixed cryoglobulinemia reflects a functional T-cell defect, which may play a role in the pathogenesis of the disease.

Topics: Adult; Concanavalin A; Cryoglobulinemia; Dose-Response Relationship, Immunologic; Female; Humans; Lymphocyte Activation; Male; Middle Aged; Paraproteinemias; T-Lymphocytes; T-Lymphocytes, Regulatory