Not All Platelet-Rich Plasma Treatments Are the Same

There are at least 16 different collection kits available on the market for platelet-rich plasma. They are not all the same and the differences may make affect results of studies trying to determine the effectiveness and long-lasting benefit of this treatment. In this article, orthopedic surgeons from Northwestern University School of Medicine in Chicago discuss the contents and preparation of these platelet-rich plasma kits.

Platelet-rich plasma (PRP) (also known as blood injection therapy) is a medical treatment being used for a wide range of musculoskeletal problems. Platelet-rich plasma refers to a sample of serum (blood) plasma that has as much as nine times more than the normal amount of platelets. This treatment enhances the body’s natural ability to heal itself and is used to improve healing and shorten recovery time from acute and chronic soft tissue injuries.

The injectable substance is created by first drawing the patient’s own blood and putting it in a special machine called a centrifuge. The centrifuge spins around at a fast rate and separates the various component parts of blood based on density and weight. The heavier red blood cells sink to the bottom faster than the lighter white blood cells and platelets.

Depending on how the blood sample is processed, the final amount of platelets and platelet-rich plasma can vary considerably. Some kits include an activator to speed up the process of clot formation (healing) but there is a potential downside. Adding an activator (e.g., calcium chloride or thrombin) can decrease how long the growth factors released by the platelets are available.

There is some research that has shown activators aren’t really needed. PRP preparations with and without activators have the same effectiveness. But other differences in PRP injections may make a difference and that is an area for future studies. Large, prospective, and randomized trials are needed to compare results using different PRP kits for each individual problem treated.

Safety is another area of concern and potential study. Since the product comes from the patient’s own blood, there is little risk involved. Rejection is not an issue. Local skin reactions, inflammation, and pain have been reported.

The positive benefits of speeding up healing are actually only part of the effectiveness of PRP. At least one study has shown that PRP increases the body’s ability to fight off staph infections and E. coli. The antimicrobial action of PRP is an added bonus to the patient.

More and more studies are showing promising results using PRP for musculoskeletal problems. The focus turns now to preparation and classification of commercially available PRP preparation systems. Some kits are categorized according to the amount of platelets in the final sample. Others look at fibrin (clotting substance) and leukocyte (white blood cell) content. The presence (or absence) of an activator further classifies these products.

For anyone interested in comparing the various commercially available PRP kits, the authors of this article provided a table reviewing six key areas. Each system is named and described according to blood volume drawn, final PRP volume, and final platelet concentration (compared with whole blood). Whether or not an activator is added is noted (along with which activator is included). And finally, the white blood cell concentration and amount of fibrinogen are listed for consideration.