Leukapheresis

Leukapheresis is a laboratory procedure in which white blood cells are separated from a sample of blood. This may be done to decrease a very high white blood cell count in individuals with cancer (leukemia) or to remove white blood cells for transfusion. In the case of cancer, usually hematological malignancies such as acute leukemias, there are white blood cell counts high enough to cause hemostasis and "sludging" in the capillaries. This can affect retinal vasculature leading to vision changes, pulmonary vasculature leading to shortness of breath from decreased efficiency in oxygen exchange, as well as other organ systems such as the brain which would become clinically apparent with neurological deterioration of a patient from cerebrovascular compromise.

Alternatively, only granulocytes, macrophages and monocytes can be removed, leaving the lymphocyte count largely unchanged. This is used as a treatment for autoimmune diseases such as ulcerative colitis and rheumatoid arthritis, where these cells play an active part in the inflammation process.

Leukapheresis, typically for granulocytes, is a rarely performed blood donation process. The product is collected by automated apheresis and is used for systemic infections in patients with neutropenia. The donor is typically a blood relative who has received stimulating medications (a directed donation), and the product is irradiated to prevent GVHD. The product generally has a 24 hour shelf life from collection and is often transfused before infectious disease testing is completed. It is a therapy of last resort, and its use is controversial and rare.

References

• G Hahn, B Stuhlmüller, N Hain, J R Kalden, K Pfizenmaier, and G R Burmester (1993). "Modulation of monocyte activation in patients with rheumatoid arthritis by leukapheresis therapy". The Journal of Clinical Investigation. 91 (3): 862–70. doi:10.1172/JCI116307. PMC 288038. PMID 8450066.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• National Institute for Health and Clinical Excellence, Leukapheresis for inflammatory bowel disease (guidance). Retrieved Oct. 06 2005
• Circular of Information for Blood Products