mechanism
Last reviewed 01/2018
Early leukocytosis is a response to the release of cytokines by body cells involved in an inflammatory or immune response. The key mediators are interleukin-1 and tumour necrosis factor. These act on bone marrow to cause an increase in number of released immature cells: the 'left-shift' response.
If the stimulus to leukocytosis is prolonged, colony stimulating factors are released peripherally by T-lymphocytes and monocytes to cause an increase in the proliferation of bone marrow progenitor cells, their differentiation and activation.