Altered apoptosis and cell cycling of mast cells in bone marrow lesions of patients with systemic mastocytosis.

Enhanced expression of the apoptosis-preventing protein bcl-xL and the cell cycle-regulating protein p21 was observed in bone marrow infiltrates of systemic mastocytosis. Expression of bcl-2, Ki67, and p53 as well as ISEL apoptosis staining were comparable in patients with mastocytosis and in controls. An altered rate of apoptosis and cell cycling may contribute to accumulation of mast cells in mastocytosis.