- Photopheresis
In
medicine , photopheresis or extracorporeal photopheresis is a form ofapheresis in whichblood is treated with photoactivable drugs which are then activated withultraviolet light .Photopheresis is currently standard
FDA -approved therapy for cutaneousT-cell lymphoma . In this procedure,buffy coat (WBC +platelet s) is separated from whole blood, chemically treated with8-Methoxypsoralen (instilled into collection bag or givenper os in advance), exposed to ultraviolet light, and returned to the patient.8-Methoxypsoralen irreversibly binds covalently to both strands of theDNA ofnucleated cells following photoactivation. The photochemically damagedT-cell s returned to the patient appear to inducecytotoxic effects on T-cell formation. The mechanism of such “antitumor” action has not been elucidated. Minimal observedside effect s for patients receiving photopheresis includehypotension andsyncope resulting from volume shifts duringleukapheresis phase of treatment. Photopheresis is also used as an experimental treatment in patients with cardiac, pulmonary and renalallograft rejection,graft-versus-host disease ,autoimmune diseases ,nephrogenic systemic fibrosis and ulcerativecolitis .External links
* [http://www.cancer.gov/Templates/db_alpha.aspx?CdrID=403135 Extracorporeal photopheresis] entry in the public domain NCI Dictionary of Cancer Terms
* [http://www.emedicine.com/derm/topic566.htm Extracorporeal photopheresis] definition at "eMedicine.com"
* [http://cutaneouslymphoma.stanford.edu/community/photopheresis.html Extracorporeal photopheresis] discussion at "Stanford School of Medicine"
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