The expression of cell surface ferritin by peripheral blood lymphocytes and monocytes

It has been suggested that the iron storage protein ferritin has a number of physiological functions not directly related to iron metabolism and a number of these relate to lymphocyte and macrophage activity. The present study demonstrates a selective distribution of ferritin on lymphocyte and macrophage surface membranes which may be relevant to these hypotheses. Flow cytometry using specific antibodies shows 66% of human peripheral blood monocytes, 75% of B cells but only 6% of T cells to have significant amounts of surface ferritin. No difference was found between OKT4 and OKT8 subsets. Ferritin was also found on the surface of the pathological lymphocytes of B cell chronic lymphatic leukaemia (CLL) but not T cell CLL.