What is the best PRP processing kit or system is an interesting question that is often asked. The problem is, without a solid framework to understand exactly how to classify PRP, “best” is a subjective term. In this sense, anyone can claim that their PRP is the “best”, and pretty much everyone in the industry does! In 2016, Magalon, J et al. attempted to create a framework in an article published in BMJ Open Sport and Exercise Medicine titled “DEPA classification: a proposal for standardizing PRP use and a retrospective application of available devices”. In this article we will summarize their findings to help you make a more informed fact-based decision.
DEPA
DEPA stands for Dose of injected platelets, Efficiency of production, Purity of the PRP, and Activation process. The purpose of these four elements is to create a standard classification of PRP systems and processes.
Dose of injected platelets: This is calculated by multiplying the platelet concentration in PRP by the obtained volume of PRP. From there, they characterized these dosages into very high, high, medium and low. Very high > 5 billion platelets; high 3-5 billion; medium 1-3 billion and low < 1 billion. Looking across 20 different PRP preparations for which biological characteristics were available in the literature they were able to determine that the dose of injected platelets of various PRP systems ranged from 210 million to 5.43 billion.
Efficiency of Production: This metric refers to the recovery rate in platelets or capture efficiency, often referred to in the industry as platelet yield. This essentially looks at the total number of platelets available in a sample of whole blood as the divisor, the dividend would be the total number of platelets counted in the PRP sample and the quotient would be your platelet yield. For example, say you draw 30cc of whole blood for PRP processing and that sample of whole blood contains a total of 7.5 billion platelets. Once it has been concentrated into 5cc of PRP you count the platelets for a total of 5 billion. 7.5/5 = .66 – so your platelet yield or efficiency of production = 66%. Here they characterized efficiency as high, medium, low and poor. High > 90%; medium 70-90%; low 30-70% and poor < 30%. Interestingly enough, in their review of the data they found that no system that was reviewed exceeded 90%. It is important to note that EmCyte was not one of the systems that was retroactively reviewed in the literature. That said, EmCyte themselves from their own data do not claim a platelet recovery rate above 90%. The recovery rates across the reviewed systems varied from 13.1% to 79.3%.
Purity of the PRP: “Purity” in this sense refers to the relative composition of platelets to leukocytes as well as Red Blood Cells (RBCs) in the final PRP Preparation. If the final PRP were pure platelets and plasma the resulting purity would be 100%. Purity is characterized as very pure, pure, heterogeneous, and whole blood. Very pure > 90% platelets; pure 70-90% platelets; heterogeneous 30-70% platelets and whole blood where platelets are < 30%. The reviewed systems produced levels of purity from 6% (whole blood) all the way to greater than 90% (very pure).
Activation Process: This doesn’t speak to the processing or production of PRP specifically, instead it refers to the post-production process of adding “activators” such as calcium chloride and thrombin. This activation does not play a direct role in the quality of the PRP produced so it is not relevant to the discussion of which PRP is the “best”.
DEPA applied to EmCyte Pure PRP
The DEPA paper reviewed 20 different systems, not directly, but through a meta-analysis of previous papers that had described the characteristics of the PRP they were using sufficiently well enough for Magalon J et al. to make a conclusion. EmCyte was not included in any of these papers. That data, however, does exist. We will be looking at a study completed in 2016 performed by Robert Mandle, PhD of the Biosciences Research Associates in Cambridge MA. This paper compared EmCyte’s Pure PRP system against Magellan PRP, Regenkit PRP and Eclipse PRP. We will strictly be looking at EmCyte’s numbers as the others are more suited for an article making a direct comparison. We have attached the study to the end of this article should you like to review it yourself.
For the study Dr. Mandle collected four separate samples of whole blood to process in four separate kits. The samples of both the whole blood and the resultant PRP were assayed for white blood cells, lymphocytes and monocytes, granulocytes, platelets and hematocrit (red blood cells). For our investigation below we will be looking at the average numbers across those 4 samples.
Dose of injected platelets
For the EmCyte GS30-PurePRP II kit, which is a 30cc whole draw dual spin kit that yields up to 6cc of PRP, the mean number of platelets in the 4 samples was 1.084 billion per mL. 5mL is right in the middle of the processing range of 4-6mL of final PRP. That would make the final dose of PRP 5.42 billion platelets. According to the DEPA classification this would rank as a very high dose. The 60cc PRP kit produced a mean 1.163 billion platelets per mL. That kit is designed to produce 8-10mL of PRP at the mid-range. This would make a final dose of 10.46 billion, once again a very high dose based on the DEPA metric.
Efficiency of production
Dr. Mandle found that the platelet recoveries for the 30cc Pure PRP and 60cc Pure PRP kits were 81% and 78% respectively. According to the DEPA metrics this would result in a medium efficiency of production. Remember, in the DEPA review they found no system that produced any yields above 90%, so no system studied would be classified in the high efficiency range.
Purity of the PRP
In the EmCyte Pure PRP preparation platelets accounted for 76% of the total solution placing it squarely in the “Pure” category. To be clear, “EmCyte Pure PRP” is a branded term for their product and is separate from the DEPA categorization of pure PRP based on content. In any event, EmCyte’s Pure PRP falls squarely in the range of pure. Another thing to keep in mind here is that the manual processing of EmCyte’s PRP system allows for a wide range of variability. As the end user you have a great deal of flexibility in exactly how many or how little RBCs and to a somewhat lesser extent the number of WBCs that are included. It is possible to create a very pure PRP in terms of DEPA classification.
Conclusion
As you can see from this article, best is a subjective term. This is something that you need to decide for yourself by not only looking at the DEPA metrics, but other factors as well. Such as, the complexity of the processing steps, size of the processing centrifuges or equipment, PRP kit price, and support for the product. When we look at all these factors, we can confidently say that EmCyte PRP is one of the best options available to you. If you would like to discuss this further, please contact us.