E-letter: Question regarding the use of autologous PRP injections for tendinopathies

The following is a letter to BJSM from Ralph S. Bovard MD:

Dear BJSM,

I have a question regarding the use of autologous platelet rich plasma (PRP) injections for tendinopathies of various sorts.  This procedure has been gaining favor with sports medicine clinicians for use in athletes with tendon injuries that are slow to respond or resistant to conservative therapies.  Despite the fact that it would appear to be a seemingly innocent matter of re-injecting one’s own spun down blood products, the World Anti-Doping Agency (WADA) most recent 2009 Prohibited List, if taken literally, would make it an illegal procedure for international competition or national competition under any NGB’s who endorse WADA.  The culprit substances in this case would be growth hormone (GH), Insulin-like Growth Factors (IGF-1), and Mechano Growth Factors (MGF’s).

The relevant section from the code is included below:

S2. HORMONES AND RELATED SUBSTANCES

The following substances and their releasing factors, are prohibited:
1. Erythropoiesis-Stimulating Agents (e.g. erythropoietin (EPO), darbepoietin (dEPO), hematide);
2. Growth Hormone (GH), Insulin-like Growth Factors (e.g. IGF-1), Mechano Growth Factors (MGFs);
3. Chorionic Gonadotrophin (CG) and Luteinizing Hormone (LH) in males;
4. Insulins;
5. Corticotrophins;
and other substances with similar chemical structure or similar biological effect(s).

[Comment to class S2:
Unless the Athlete can demonstrate that the concentration was due to a physiological or pathological condition, a Sample will be deemed to contain a Prohibited Substance (as listed above) where the concentration of the Prohibited Substance or its metabolites and/or relevant ratios or markers in the Athlete’s Sample satisfies positivity criteria established by WADA or otherwise so exceeds the range of values normally found in humans that it is unlikely to be consistent with normal endogenous production.

If a laboratory reports, using a reliable analytical method, that the Prohibited Substance is of exogenous origin, the Sample will be deemed to contain a Prohibited Substance and shall be reported as an Adverse Analytical Finding.] The Prohibited List 2009 20 September 2008

It would thus seem that PRP is banned under “Class S2: Hormones and Related Substances”, rather than under “M1: Blood Doping”.  The re-delivery of blood is prohibited under blood doping; regardless of whether it is endogenous or exogenous.  There is no mention or attempt to discriminate between blood products that are re-injected immediately into soft tissues versus those that are shelved and re-infused by IV weeks or months later in the typical manner of “blood doping”.

The argument is made that while PRP indeed delivers  the athletes own growth factors to a musculoskeletal site, the platelets are concentrated to a level not normally achieved physiologically, and they are activated either chemically (via calcium addition) or mechanically (centrifugation) and thus degranulate  rapidly and deliver a bolus of factors never “normally” or physiologically achieved.

Given this stance it would seem that the use of platelet rich plasma injections is clearly prohibited.   Tendinopathies are not life threatening or otherwise serious medical conditions and as such the rational of applying for a therapeutic use exemption (TUE) would seem a difficult argument.   Yet how would PRP injections be detected other than by admission?  What is the opinion of the BJSM readership regarding this topic?

Thank you,

Raph S. Bovard MD

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