Home › Blog › How to Stop Knee Pain: Why PRP and Stem Cells Beat A2M Injections

For many patients, slowing the progression of arthritis is a great way to help stop knee pain in its tracks. One of the newest methods now offered by physicians involves A2M, a naturally occurring chemical in the blood that has been shown to slow arthritis progression in animals. But do you need to seek an A2M-specific treatment–or is A2M already a part of the platelet rich plasma (PRP) and stem cell procedures that are currently available for knee pain? First let’s learn about A2M–then we’ll be able to answer this question clearly so you can decide what type of treatment is best for you.

What is A2M?

A2M stands for alpha-2-macroglobulin. We’ve known about this chemical–officially classified a cytokine–for over 50 years, so it’s not a new discovery. In fact, it’s circulating in your blood right now. What’s new is the idea that A2M might help slow arthritis progression.

One of the hallmarks of arthritis is that the cartilage breaks down and wears away. One of the cytokines in the joint that’s responsible for chewing up healthy cartilage goes by the moniker of MMP (matrix matelloproteinase). There are many of these MMPs in the joint, and some of them can cause your cartilage to degrade. We’ll call MMPs the “bad guys” since they’ll destroy a joint if left unchecked. Chronic inflammation also plays a part in this chemical dance as it enhances the ability of the bad guys to kill cartilage. So think of inflammation as an accomplice–someone who provides the bad guys with the tools they need to commit the crime.

Where does A2M fit into all of this? Think of A2M as a good guy whose job is to bust the bad guy. Basically, it helps block MMPs, which in turn prevents cartilage breakdown. If you have healthy knees, it’s likely that you already have high levels of A2M keeping the MMPs in check. In addition to A2M, many other types of good guys exist to help fight cartilage degradation, like IRAP and TIMP. An arthritic joint may be caused by deficiencies in A2M, IRAP, and/or TIMP.

Can A2M Shots Stop Knee Pain?

Current research says that A2M can help block cartilage breakdown. In an animal study, when researchers found that there wasn’t enough A2M already in the blood to block cartilage breakdown, they injected more A2M around the joint and found a decrease in arthritis progression. Through their research, they discovered the concentration level of A2M that was needed in order to stop arthritis in the joints.

We now have two systems that doctors can use to concentrate A2M in the blood so that it can be injected into a joint. The doctors buying these machines believe they can treat arthritis with this A2M-specific method. In addition, we have many other types of biologic injections being prescribed such as platelet-rich plasma (PRP), platelet-poor plasma (PPP), and bone marrow concentrate (BMC), which all also seem to help arthritis. But could it be that they, too, contain a healthy concentration of A2M?

The video above is fairly complex, but I’ve mixed in a some slides that help keep it simple to understand. It shows that when we measured A2M levels in the common biologics that are being injected to treat knee arthritis, all had fairly high levels of A2M–much more than the minimum amount needed to block cartilage breakdown. Lastly, when we compared the amount of A2M that was already in the joints of patients before our stem cell procedure at Regenexx, the levels of A2M in the joint after the treatment all far exceeded the amount needed to block cartilage breakdown. At this point, there seems to be little rationale for concentrating A2M with one of the new systems coming onto the market, as PRP and stem cell injections already have high concentrations of the stuff, with all of the additional benefits offered by these biologic treatments.

Perhaps one day someone will prove that concentrated A2M helps arthritis more than other cytokines do, but we don’t have evidence of that right now. As far as I’m aware, there are no studies underway that are designed to answer that question as they don’t compare A2M injections to more common treatments, like PRP.

The upshot? If you have mild arthritis, your best bet is likely a PRP injection. If you have severe arthritis, you’ll likely benefit even more from a bone marrow stem cell procedure. On the latter topic, I can say with great confidence that the amount of A2M in your knee will likely rise to much higher levels after our patented knee stem cell procedure.

Hopefully this has helped shed some light on your options for treating knee pain. While we agree with recent research on A2M’s critical role in keeping your knees healthy, we advise against procedures focused only on injecting concentrated A2M. Since PRP and stem cell injections already raise A2m levels in your joints, help reduce knee pain, and slow the progression of arthritis, it’s likely the most reliable option for you on your journey to reclaim your health.

To find out if you might be a candidate for a Regenexx stem cell procedure, complete our Regenexx Procedure Candidate Form online.

Chris Centeno, MD is a specialist in regenerative medicine and the new field of Interventional Orthopedics. Centeno pioneered orthopedic stem cell procedures in 2005 and is responsible for a large amount of the published research on stem cell use for orthopedic applications. View Profile