Origin of human mast cells studied by dual immunofluorescence.

Previous reports have suggested that mast cells derive either directly from basophils or mononuclear phagocytes, or from a common myeloid precursor. We have used monoclonal antibodies to investigate expression by normal human tissue mast cells of antigens characteristic of other haemopoietic lineages. We find that mast cells express panhaemopoietic markers, but not antigens typical of either myeloid or lymphoid cells. We propose, therefore, that mast cells form a distinct lineage, only distantly-related to other haemopoietic cells.