Stem cell therapy and Platelet Rich Plasma (PRP) therapies are becoming increasingly popular for the treatment of many musculoskeletal degenerative disorders. While appearing promising as a means of decreasing pain and in some cases reversing disease, there remains many unknowns in regards to the ideal concentrations, treatment protocols, and long term effects of these treatments.
Add Alpha-2-macroglobulin to the short list of treatments that fall under the umbrella of regenerative medicine. Alpha-2-macroglobulin or A2M is a naturally occurring protein in the body that inhibits proteases (enzymes) that cause deterioration of cartilage which leads to arthritis.
Three protein classes which include cytokines, matrix metalloproteinases, and ADAMTS that have been identified as the culprits that cause the breakdown of cartilage cells leading to damage of joint surfaces. A2M has been shown to inhibit or inactivate these chemicals. Researchers have found that natural concentrations of A2M in the body may not be sufficient enough to protect the joints from the development of osteoarthritis. In response, a super concentrated form of A2M has been developed which can be injected into the joints. In fact, clinical trials of A2M (phase I/II) were approved by the FDA and began in May 2015. Data from this double blind, efficacy and safety study was recently reported and phase III trials are soon to begin.
At present, A2M is only being tested on patients with osteoarthritis of the knee. Unlike cortisone treatments, A2M does not appear to have negative side effects. Furthermore, A2M protects the joint surface and decreases inflammation.
As a new biologic treatment, targeted at treating osteoarthritis, A2M therapy has the potential to one day replace conventional treatments.
Wang S et al. Identification of alpha2-macroglobulin as a master inhibitor of cartilage degrading factors that attenuates the progression of posttraumatic osteoarthritis. Arthritis Rheumatol. 2014 Jul; 66(7): 1843-1853.