Abstract
We investigated whether T cells and macrophages from peripheral blood of patient with monoclonal immunoglobulinemias suppress the immunoglobulins sythesis by cocultured normal lymphocytes in the presence of pokeweed mitogen. Immunoglobulin-secreting cells (plaque forming cells) were enumerated in a Protein A-reverse hemolitic plaque assay.
It was found that the macrophages from four of eight patients with myeloma significantly inhibited the capasity of B cells to mature into immunoglobulin secreting cells. Moreover, the immunoglobulin production by normal lymphocytes was also noted to be suppressed in co-culture with the macrophages from normal individuals that were with the culture supernatant in myeloma cell line (H.T.). The suppressor T cells from patient with myeloma or benign monoclonal immunoglobulinemia had no effect on the immunoglobulin secreting cells.
These results suggest that the macrophages, which are stimulated with a factor released by myeloma cells, mediated the suppressive effect on immunoglobulin production by B cells in certain patients with myeloma.
