Serum IgD and suppressor T cells in patients with multiple myeloma

Abstract

The serum IgD level in patients with multiple myeloma was measured by ELISA.
There was no difference in the serum IgD level between myeloma patients and normal donors. In contrast, other class of serum immunoglobulin levels were remarkably depressed in multiple myeloma patient. The characteristics of periferal mononuclear cells from myeloma patients were in vestigated by flow cytometry using monoclonal antibodies against CD 8 and CD 11b antigen. The ratio of suppressor T cells with both CD 8 and CD 11b antigen in myeloma patients was ramarkably increased compared to normal donors.
The increase in the suppressor T cells ratio was higher, especially in myeloma not accompanied by Bence-Jones protein.
This depression of the serum immunoglobulin except IgD was related to the increase of suppressor T lymphocyte in multiple myeloma. Our observations suggest that the mechanism of the regulation of the serum IgD levels and the roles of the serum IgD are quite different from other classes of immunoglobulins.