• Similarly to basophils, mast cells are granulocytes mainly involved in IgE-mediated allergic reactions in addition to other inflammatory responses.
• In contrast to basophils, mast cells reside in connective tissues and don't circulate in the blood thus are undetected in peripheral blood sample.
• Most diagnostic workup for mast cell disorders require direct sampling of the bone marrow and the infiltrated tissue.
• Serum tryptase level is used as a surrogate for mast cell count and activity level because tryptases are made predominantly in mast cells.
• Mast cell number increases in sytemic or cutaneous mastocytosis and certain neoplastic, infectious, and immunologic disorders (listed below) and
decreases in certain immunodeficiencies or glucocorticoid use.
