Basophil and mast cell lineages in vitro and in vivo.

VER SINCE Paul Ehrlich’s discovery that granuleE laden cells (“mastzellen”) in the frog mesentery, originally observed by von Recklinghausen, possessed metachromatic staining properties,’” cells in the basophil and mast cell lineages have been the subject of much scrutiny. The description by dermatologists at the turn of the century of the condition known as urticaria pigmentosa, involving mast cell infiltration in the skin and other organs?4 and subsequent findings that mast cells contain various preformed mediators of inflammation such as histamine: led gradually to a widespread fascination with the role of these cells in biologic processes. In parallel with these observations were descriptions by Ehrlich’ and later by hematologists of the presence of a blood-borne metachromatic, histamine-producing granulocyte, the basophil, significantly prominent in a number of myeloproliferative diseases, especially in chronic myeloid leukemia: Historically, because of their common metachromatic staining properties, the basophil and the mast cell have been thought to be intimately related in terms of hematopoietic lineage, and the literature is indeed replete with this assumption. The mast cell in the tissue and the basophil in the blood have, however, not been proven to be derived from a common stem cell in either animals or humans; moreover, there appears to be an inverse relationship between the presence of basophils or mast cells as the prominent representative of a metachromatic cell among various species.’ This review will focus on the ontogeny of basophils and mast cells, exploring knowledge in this field as it relates to cytokine biology, allergy and inflammation, and clinical hematology. The extensive literature on the biology of the mast cell in various processes, such as wound healing, repair, and fibrosis or on basophil and mast cell secretory function, will be touched upon only briefly within the scope of this review.