Colony-stimulating factors processing

Erythropoiesis is a process that starts with a pluripotent stem cell in the bone marrow that eventually differentiates into an erythroid colony-forming unit (CFU-E)4 (Fig. 63-1). The development of these cells depends on stimulation from the appropriate growth factors, primarily erythropoietin. Other cytokines involved include granulocyte-monocyte colony-stimulating factor (GM-CSF) and interleukin 3 (IL-3). Eventually, the CFU-Es differentiate into reticulocytes and cross from the bone marrow into the peripheral blood. Finally, these reticulocytes mature into erythrocytes after 1 to 2 days in the bloodstream. Throughout this process, the cells gradually accumulate more hemoglobin and lose their nuclei.4... 

Acute febrile neutrophilic dermatosis, also known as Sweet syndrome, is a reactive process characterized by the abrupt onset of tender, red-to-purple papules, and nodules that coalesce to form plaques. The plaques usually occur on the upper extremities, face, or neck and are typically accompanied by fever and peripheral neutrophilia. Common causes of this disorder are Granulocyte Colony-Stimulating Factor (35 references), hydralazine and co-trimoxazole. 

Egress of more mature cells from the bone marrow occurs through the endothelial cell barrier. Release of cells such as neutrophils may be stimulated by complement, steroids, or endotoxin. Immature (progenitor) cells that may ultimately become any one of the blood cellular components can be mobilized from the bone marrow into peripheral blood by the administration of a cytotoxic chemotherapy drug (e.g., cyclophosphamide) or a colony-stimulating factor (G-CSE or GM-CSE). This process is commonly referred to as priming the bone marrow for peripheral blood progenitor or stem cell transplantation (see Chap. 134). 

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