Mast cell hyperplasia: role of cytokines.

Mast cell hyperplasia is found in different pathologies such as chronic inflammatory processes, fibrotic disorders, wound healing or neoplastic tissue transformation. The functional significance of the accumulation of mast cells in these processes is largely unknown. It is now established that bone marrow-derived mast cell progenitors circulate in peripheral blood and subsequently migrate into the tissue where they undergo final maturation under the influence of local microenvironmental factors. Cytokines are of particular importance for mast cell recruitment, development, and function. Stem cell factor (SCF) is a unique mast cell growth factor, since mast cells disappear completely in the absence of SCF. However, several other cytokines such as IL-3 and IL-4 have been shown to influence mast cell proliferation and function also. This review focuses on the role of cytokines in the regulation of mast cell hyperplasia.