Every once in a while, I come across websites that claim that PRP is a stem cell treatment. While it’s hard to believe in 2017 that physicians are still making this error, given the almost-next-to-near-zero state of regenerative-medicine education for physicians in this field, I’ll believe anything. So is PRP a stem cell treatment? Nope. Let me explain.
The good news is that pretty much every part of your body has some sort of adult stem cell population. This includes bones, fat, muscles, tendons, organs, and so on. However, one of the places you won’t find many stem cells is in the blood. Why? While an occasional stem cell hitches a ride from point A to point B using the circulatory system, these are very rare events.
Since there are plenty of stem cells that live in the bone marrow, there is a way you can get a few stem cells from there to mobilize into the blood, but that requires heavy drugs. For example, in this rabbit study, they induced a few stem cells from the bone marrow to mobilize into the peripheral blood by giving the animals G-CSF and AMD-3100. These few cells then needed to be culture expanded (grown to bigger numbers) to end up with any significant number of cells.
As I said above, there are a few stem cells that you can find floating around in the peripheral blood in some patients. In this 2013 study, they took blood from six people and then plated it for culture expansion and found one small stem cell colony in only one of the six donors. They then cultured those cells to get any significant number. For comparison, a bone marrow sample from each donor would have shown hundreds of colonies in each flask plated with far lower volume.
Many years ago, in 2008–9, we were asked by a company involved in “stem cell” banking to test their blood-derived product. The company wanted to determine if the patients who had gone through peripheral-blood apheresis after a G-CSF mobilization could use these cells for our orthopedic treatments. They sent over a number of units of blood that they had collected, and we tried to culture these cells. Regrettably, none of the blood samples they sent yielded any stem cells, and the project was abandoned.
This project was most similar to the rabbit study discussed above. Apheresis is a process whereby certain cells are removed from the blood via a machine and then the rest of the blood is returned. G-CSF is a drug called Neupogen that is often used in cancer care and has a healthy side-effect profile. In the rabbit study above, they also used AMD-3100 (plerixafor), which is a drug that was new on the market in 2008–9 and wasn’t used by the company back when we did this experiment. It also has a healthy side-effect profile.
If you see physicians who claim to obtain stem cells from blood or claim that PRP (platelet rich plasma or concentrated blood platelets) is a stem cell therapy, run fast in the other direction. These physicians don’t know what they don’t know. As you can see, these statements aren’t remotely true. If you use two heavy-handed drugs and perform apheresis and culture expand the few cells you’ll find, you can get some stem cells in a process that’s a fraction of a percent as efficient as just culturing bone marrow. However, using these drugs in a healthy patient is a risky proposition.
The upshot? Is PRP a stem cell treatment? Absolutely not! It’s crazy out there! Make sure the physicians you’re working with know which end is up. If they claim that they can take your blood and get loads of stem cells, find a new physician!
About the Author
Christopher J. Centeno, M.D. is an international expert and specialist in regenerative medicine and the clinical use of mesenchymal stem cells in orthopedics. He is board certified in physical medicine as well as rehabilitation and in pain management through The American Board of Physical Medicine and Rehabilitation.…