Mast cells in mastocytosis and allergy - Important player in metabolic and immunological homeostasis.

The role of mast cell (MC) activity in pathophysiology is complex and challenging and its clinical effects are difficult to predict. Apart from the known role of MCs in basic immunological processes and allergy, underlined is their importance in bone mineralization and in regulation of autoimmune reactions. Mast cell mediators, especially those released from mast cells in degranulation, but also those released constitutively, are important both in metabolic and immunological processes. Mastocytosis is a heterogeneous group of disorders characterized by accumulation of MC in one or more organs. There are scientific data indicating that mastocytosis patients are at increased risk of osteoporosis in the systemic form of the disease and children with cutaneous mastocytosis have a higher rate of hypogammaglobulinemia. Moreover, the origin of osteoporosis in patients with allergy is no longer considered as linked to steroid therapy only, but to the mast cell mediators' activity as well. There are indications that osteoporosis symptoms in this group of patients may develop independently of the cumulative steroids' dose. Thus, the influence of mast cells on metabolic and immunologic processes in allergic patients should be investigated. The assessment of mast cell activity and burden in mastocytosis may be used to guide clinical management of patients with allergy.