Transfer factor
This article needs more primary sources. (January 2013) |
Transfer factors are essentially small immune messenger molecules that are produced by all higher organisms.[1] Transfer factors were originally described as immune molecules that are derived from blood or spleen cells that cause antigen-specific cell-mediated immunity, primarily delayed hypersensitivity and the production of lymphokines, as well as binding to the antigens themselves. They have a molecular weight of approximately 5000 daltons and are composed entirely of amino acids.[2] Transfer factors were discovered by Henry Sherwood Lawrence in 1954.[3]
A second use of the term transfer factor applies to a likely different entity [4] derived from cow colostrum or chicken egg yolk which is marketed as an oral dietary supplement under the same name citing claims of benefit to the immune system.[5]
History
In 1942, Merrill Chase discovered that cells taken from the peritoneum of Guinea pigs that had been immunized against an antigen could transfer immunity when injected into Guinea pigs that had never been exposed to the antigen; this phenomenon was the discovery of cell-mediated immunity. Subsequent research attempted to uncover how the cells imparted their effects. Henry Sherwood Lawrence, in 1955,[3] discovered that partial immunity could be transferred even when the immune cells had undergone lysis - indicating that cells did not need to be fully intact in order to produce immune effects.[6] Lawrence went on to discover that only the factors less than 8000 daltons were required to transfer this immunity; he termed these to be "transfer factors".[3]
The history of cellular derived transfer factor as a treatment effectively ended in the early 1980s. While the research world was initially excited by the discovery of Dr. Lawrence and the possibility that a small molecule could affect the immune system, the concept of small molecules having such profound biologic effect had not been proven.
Most recently, transfer factor has been harvested from sources other than blood, and administered orally, as opposed to intravenously. This use of transfer factors from sources other than blood has not been accompanied by the same concerns associated with blood-borne diseases, since no blood is involved. Transfer factor based nutritional supplements have become extremely popular throughout the world. However the way transfer factor works is still not clear.
Scientific claims
To communicate between cells, the immune system employs hormone-like signal substances; transfer factors are one class of such immune system communication substances. Transfer factors include both inducer/helper functions (Inducer Factors) and regulator functions (Regulator Factors)—historically called "suppressor functions".[9] The Inducer Factors translate an apparently mature immune response from the donor to the recipient. Regulator Factors help control overreactions and limit allergies and autoimmune conditions. Transfer factors have been shown to induce an immune response in less than 24 hours.[9] Transfer factors are not species-specific, thus transfer factors produced by a cow's immune system are just as effective in humans as they are in the cow.
Henry Sherwood Lawrence discovered that blood cells could 'transfer' antigen-specific cell-mediated immunity even after the cells had undergone lysis.[3] This lymphocyte product is sometimes referred to as "dialyzable leukocyte extract" in the scientific literature due to being an extract from white blood cells undergoing dialysis to remove all molecules larger than ~5000 daltons.[10] Studies on cellular transfer factor have involved mostly animal models and small human clinical trials. These studies have demonstrated preliminary evidence of immune modulation as well as some clinical benefits in a handful of diseases, but the studies not been assessed beyond primary sources and the trials should only be considered pre-clinical.[11][12]
The exact identity (
LLYAQD[LV]EDN
, a sequence not found in any mammalian genomes.[13]Uses
Despite a small modicum of successes,
Instead, transfer factors derived from cow colostrum and/or chicken eggs yolks are used predominantly today.
Side effects
Colostrum-derived transfer factors
Long-term oral administration of colostrum-derived transfer factors has been shown to be safe.[15][16]
Blood-derived transfer factors
Human-derived transfer factor appears to be safe for use for up to two years and bovine-derived cellular (from blood sources) transfer factor for up to three months. Side effects include fever and swelling and pain at the injection site. Concern has been raised over the possibility of catching Bovine spongiform encephalopathy (Mad Cow Disease) or other diseases from animal blood-derived products. Transfer factors are contraindicated for women who are pregnant or breastfeeding.[4] When human- and bovine-derived transfer factor are generated from blood cells[3][17] they carry the potential for blood-borne disease such as HIV/AIDS and Hepatitis C.
Transfer factor (dietary supplement) history, claims, and side effects
Colostrum/egg derived transfer factors have been promoted as a treatment for a large number of diseases and health concerns but have not been proven effective in the treatment of any of these conditions.
See also
References
- ISBN 0838540643.
- S2CID 38598931.
- ^ ISBN 978-0-309-12148-4.
- ^ a b c d "Transfer Factor". WebMD. Retrieved 2010-02-16.
- ^ PDR "4LIFE TRANSFER FACTOR TRI-FACTOR FORMULA | Product Labeling | PDR.net". Archived from the original on 2013-01-06. Retrieved 2013-01-14.
- PMID 13233344.
- ^ a b Chedd G (1974-12-26). "Transfer factor - Another scandal?". New Scientist. Vol. 64, no. 929. pp. 920–1.
- ^ "The History of Transfusion Medicine". BloodBook.com. Archived from the original on 12 April 2018.
- ^ S2CID 18338437.
- S2CID 22904120.
- PMID 22705080.
- ^ PMID 18297853.
- PMID 10949913.
- PMID 9839657.
- S2CID 23126833.
- ISBN 1483277682.
- PMID 10949913.
- .
- PMID 2897772.
- ^ Memorial Sloan–Kettering Cancer Center. 2009-10-08. Retrieved 2010-02-16.
- ^ Barrett S (2007-03-28). "Be Wary of Multiple Sclerosis "Cures"". Quackwatch. Retrieved 2010-02-12.
- ^ Barrett S (2005-06-02). "Warning Letter". Quackwatch. Retrieved 2010-02-12.
External links
- Transfer+factor at the U.S. National Library of Medicine Medical Subject Headings (MeSH)