By Phillip Steele, MD RMSK, CAQ Sports Medicine
Performance Injury Care & Sports Medicine
Platelet Rich Plasma (PRP) has been found to have a higher concentration of Alpha 2 Macroglobulin (A2M), which has a strong anti-inflammatory effect to prevent breakdown of cartilage in joints. It also appears to promote tissue growth and support the overall restoration of osteoarthritic (OA) joints.
Scientific evidence supports that A2M is a key factor in slowing the progression of OA at the molecular level Simply, A2M is a powerful protein that acts by destroying degradation factors found in arthritic joints. Many research articles are now available that have shown that a healthy joint will have higher concentrations of A2M helping to balance the forces between regeneration and degeneration. When A2M concentrations are sufficient in a joint they provide cartilage protection by binding to and breaking down degradation proteases. A2M also acts to bind and regulate cytokines (small proteins that act by signaling other cells) and growth factors. It also blocks all known causes of cartilage degradation. This helps to promote the healing process, reduces pain, promotes increased strength of tissues, and improves overall function of the joint.
When measuring the levels of A2M in arthritic joints, most joints will have too low of a concentration to provide sufficient protection against catabolic (breakdown) factors found in the synovial fluid. Simply put, A2M protects your joints from the complexes that cause your joints to ache and wear out.
Although it is too early to know the full story as research is still preliminary, A2M inhibits the breakdown of cartilage and shuts down the destructive inflammatory proteins found in your joints. By acting early in the course of OA, during the acute phase of the disease, injections of A2M may slow the progression of OA, relieve pain, hinder or prevent cartilage loss and promote tissue growth and support for joint regeneration.
Some research has suggested that this powerful protein should be used after joint injuries or surgery to help prevent arthritis down the road. By injecting A2M back into your joints either by an A2M injection or a PRP (Platelet Rich Plasma) injection, this protein will bind to destructive factors and help your body eliminate them and help promote recovery from surgery or injury. Due to the large size of this A2M protein it cannot easily make its way into a damaged joint. Although made in your liver and found in your blood, it is not a product from platelets, but is found in the plasma concentrated during centrifuging for PRP. We currently inject what we call releasate into your joint during a PRP procedure. Releasate is made from the protein poor plasma (PPP) we used to throw away during the concentration of PRP. By adding thrombin (clotting factor) to the PPP we are injecting a high concentration of growth factors and A2M into your knee.
A2M can also be concentrated from your blood through a special process that we offer to our patients. However, we generally believe that releasate, PRP & stem cell procedures have sufficient quantities of A2M. As both stem cell and PRP procedures have higher concentration of A2M than an osteoarthritic joint, they also have the added advantage of other anti-catabolic cytokines such as TGF-beta (transforming growth factor), TIMP-1 & 2 (tissue inhibitor of metalloproteinase), IRAP (interleukin receptor antagonist protein).
At this time we feel that A2M is a powerful protein that helps to decrease degenerative forces in an arthritic joint. Whether or not it is better, equal or less effective than PRP, PPP, releasate, or stem cell procedures is unknown. As no study is currently available comparing the effectiveness of A2M injections to PRP or stem cells; only more research will tell. As PRP and stem cell procedures raise A2M levels in your joint, a concentrated A2M procedure should be considered in addition to or after PRP and stem cell therapy has been completed. Used early in the course of osteoarthritis, PRP, stem cell, releasate or A2M therapy may help you recover from surgery, recover from an injury and help prevent the development of early onset osteoarthritis.