Chicken collagen II is type II collagen derived from the sternum of chickens. Type II collagen is the most abundant collagen found in hyaline cartilage (in synovial joints, sternum, respiratory tract), comprising 80 to 90% of the total collagen content. Chicken collagen II is also known as type II chicken collagen and is abbreviated as CCII.
Type II chicken collagen shares some similar antigenic regions with type II human collagen. Autoimmune response to type II collagen is thought to be a significant factor in the pathogenesis of rheumatoid arthritis. A few studies suggest that oral type II chicken collagen may be beneficial to some with rheumatoid arthritis, acting by a process known as oral tolerance.
Chicken collagen type II may have anti-rheumatoid arthritis activity in some.
MECHANISM OF ACTION
The mechanism of the possible anti-rheumatoid arthritis activity of chicken collagen type II may be through oral tolerance. Oral tolerance refers to the observation that if a protein is orally administered, subsequent immunization with the protein leads to a state of systemic hyporesponsiveness to it. Autoantibodies to type II collagen are thought to play a role in the pathogenesis of rheumatoid arthritis. Therefore, feeding antigenic type II collagen may be predicted to lead to the induction of immune tolerance to type II collagen, especially in the context of elevated autoantibodies to this substance.
The mechanism for oral tolerance appears to depend on the dose of the fed antigen. Low doses appear to induce active suppression, while high doses result in clonal anergy. Suppressive cytokines, such as interleukin-4 and transforming growth factor beta, appear to mediate active suppression. Studies in animals demonstrate the generation of regulatory lymphocytes in Peyer's patches, which subsequently migrate to mesenteric lymph nodes and spleen. Secretion of suppressive cytokines by these cells is believed to depend on antigen-specific stimulation with the fed antigen. Further, it is believed that active suppression of the inflammatory process by the regulatory lymphocytes requires their migration to the location where the fed antigen is present. Since the clinical studies to date indicate that low doses, but not high doses, have possible mild efficacy in rheumatoid arthritis, the mechanism responsible for oral tolerance would appear to be induction of active suppression, rather than clonal anergy.
There are no reports on the pharmacokinetics of chicken collagen type II. The pharmacokinetics of the substance should be similar to those of dietary proteins.
INDICATIONS AND USAGE
Chicken collagen II may offer some mild benefit for some with rheumatoid arthritis.
A multicenter, randomized, controlled trial of oral type II collagen derived from chicken cartilage tested the substance in four different daily doses versus placebo in 273 rheumatoid arthritis patients. Various criteria were used to evaluate the results. The daily dose levels were 20 micrograms, 100 micrograms, 500 micrograms and 2,500 micrograms.
Results were negative at all dose levels except the lowest dose (20 micrograms daily). The difference in response between this dose level and placebo was significant only with respect to what was described as the weakest of the evaluative criteria. A post hoc analysis revealed that those who had antibodies reactive with type II collagen in their serum (at the baseline exam) were more likely to respond to collagen administration.
More research is needed, in part to investigate whether still lower doses might further improve efficacy of this antigenic substance
CONTRAINDICATIONS, PRECAUTIONS, ADVERSE REACTIONS
Chicken collagen II is contraindicated in those who are hypersensitive to any component of a chicken collagen II-containing product.
Because of lack of long-term safety studies, nutritional supplements containing chicken collagen II should be avoided by pregnant women and nursing mothers.
Those with rheumatoid arthritis who are interested in trying chicken collagen II should consult with their physicians before doing so.
Chicken collagen type II supplements are generally well tolerated. There is one report of transient flushing in a patient with juvenile rheumatoid arthritis.