Therapeutic concentrations of melphalan do not affect yeast cell phagocytosis by monocytes

The effect of melphalan on monocyte phagocytosis was assessed by studying the uptake of fluorescent yeast cells by glass-adherent monocytes (a fluorescence-quenching technique). In contrast to several other cytotoxic agents, melphalan did not inhibit monocyte phagocytosis. Although the main immunosuppressive side effect of most cytotoxic drugs appears to be due to bone marrow depression with reduction of leukocyte counts, it is reasonable to assume that lack of interference with the function of mature leukocytes is a favourable feature of an antineoplastic drug.