A study of certain functional parameters of monocytes from patients with multiple myeloma: comparison with monocytes...

Selected functions (i.e. phagocytosis and chemotaxis of circulating blood monocytes were studied on cells obtained from 20 patients with untreated multiple myeloma (MM) and the results were compared with those obtained on cells from 60 healthy persons. The mean number of circulating monocytes was only slightly increased over the normal value although a marked monocytosis was demonstrated in all of the 4 patients with M-components of the lambda light chain type. Plasma cells isolated from peripheral blood and from bone marrow of patients with MM were found to possess a strong alpha-naphthyl acetate esterase activity. No differences were observed in the phagocytic activity of monocytes from patients compared with those of the controls, whereas the chemotactic responsiveness of the monocytes from the patients was slightly increased.