“We know nothing, we’ve got everything to learn” (George Sand)

RSI, volume, dose of platelets, concentration and purity

“We know nothing, we’ve got everything to learn” (George Sand)

RSI, volume, dose of platelets, concentration and purity

Volume of Sampling: Quantity of Platelets

The term platelet rich plasma supposes an enrichment in platelets, above the usual concentration of 145 to 400 10E09/l.

Old gel tubes generating poor PRP

The dose of platelets, and therefore the amount of released growth factors, depends directly on the volume of the sample, the platelet recovery rate, and the volume of PRP obtained.
The PRP applications are so broad that it is difficult to speak of an ideal volume. The minimum volume can, however, be defined in terms of the minimum requirement for platelets doses around 1 to 2 billion. Since the general PRP equation tells us that the platelet dose is related to the RSI of a device and the volume of the PRP produced, it can be estimated that a useful device has an RSI greater than or equal to 3 or 4. Please refer to our general comparison to see the current market offer summarized in a single table.
Most manufacturers only emphasize the concentration factor, to the detriment of platelet dose, volume and purity of PRP. We will discuss now once and for all the concept of concentration, which is a poor indicator of PRP.

Concentration: a false problem

The platelet concentration expressed in relation to the normal blood concentration of 1 is worth mentioning here since the PRP volume necessarily contains more platelets than the same volume of blood.
From which platelet concentration fold can we call PRP a plasma rich platelets? Such a definition has a semantic interest but above all a link with the required clinical efficiency we’re looking for.
Let’s take again as an example the simplest device available on the market: the gel tube. One of the most famous companies, Regenlab® gives the following data (the numbers are not very high but at least the product obtained is very pure, containing very few RBC):

Regenlab PRP concentration

Another manufacturer, Harvest®, claims different PRP concentration (we let the users decide whether the device is worth the investment or not for these numbers):

A third one, Biomet® announces an even higher concentration (but apparently to the detriment of the purity judging by the red color of the product):

Facing so many different concentrations, one has the right to wonder how to define what a “genuine” PRP would be. And above all if there is a link between concentration and efficiency. It’s interesting to discover if a general agreement exists amongst the medical community. A simple query on the famous website Realself.com gives a value around 4x to 6x.

Clinical studies will provide the data to understand the issue, here are about twenty of them:

Each PRP device manufacturer will tend to praise the concentration that their device can achieve. Some users let themselves be persuaded that 2x represents the best of the PRP, others that it is 5x, and so on.
The overall conclusion pinpoints the need for an appropriate platelet concentration in order to reach clinical results. The lowest concentration studied here was 1.9x, the highest 17x. In the literature we quote, most of the authors have been using a 3x to 8x concentration.
The minimum concentration level to call PRP a platelet concentration is 3x.
However, contradictory information is still circulating, suggesting that it is impossible to concentrate beyond 11x, or that an excess of platelets would inhibit the cell proliferation response.
These data are largely out-of-date, as more studies show [see « Epidermal growth factor released from platelet-rich plasma promotes endothelial cell proliferation in vitro », etc.] Let us also quote the experiments of Chris Centeno with his remarkable process to concentrate 20x plasma on YouTube, unfortunately not reproducible outside the hospital environment.
What should be borne in mind are the latest developments: with age, platelets contain fewer growth factors, just as cells have fewer receptors on their surface. It is therefore clear that the more the PRP can be concentrated, the better the effect will be. In younger subjects with factor-rich platelets and numerous receptors on the surface of the cells, it will be possible to saturate the response more rapidly beyond a certain concentration. With them, 10x or 20x will probably make no difference.
With the WorldPRP kit you can vary the concentration between 3x and 32x.
However, this is of little importance because the essential factor of PRP is the useful dose of platelets that we will now discuss.

Platelet Dose

The WorldPRP kit represents a good compromise with 25 ml of volume, which makes it possible to obtain useful doses of 2.75 to 9 billion platelets. No other device can match this data.
Of course it’s possible, and even advised, as for example in the treatment of the scalp, to add in the same PRP volume the platelets collected in a second kit. The draw sample will be then of 50 ml, and this is a good way to increase the dose. The platelet recovery rate is about 87% in this case!
Depending on the preparation pathways taken to achieve your PRP, you get 8 PRPs with different properties. In the concentration pathway your PRP will have an RSI of 7 to 17, which corresponds to an RSI Dose between 16 and 44 (that is the highest to be found on the market). See the comparisons to discuss these concepts in detail.


Purity: RBC

We can find very expensive devices on the market capable of automatically concentrating the platelet rate up to 5x, giving a platelet dose of about 5 billions, but they all have one thing in common: the PRP is systematically contaminated by red blood cells

“PRP” fully contaminated with blood

(which should be avoided as much as possible in order to prevent ferrous deposits and other inflammatory disorders). Given the price of this equipment and their consumables, it is probably not a good deal.have one thing in common: Conversely, there are devices capable of obtaining a good purity of the PRP obtained, in particular of the gel tubes. However in this case, the concentration and dose cannot be obtained. A factor x2 as claimed by some manufacturers is only obtained by reducing the volume of the solute by half (water of the plasma in the gel, red cells separated by the gel), but in no case by active concentration of platelets, especially since many thrombocytes are trapped in the gel (if the red blood cells can cross the mesh of the gel, then what happened to the thrombocytes that are twice smaller?) We can add here that gel particles are undoubtedly injected to the patients. What about the safety of this substance?
The WorldPRP kit is a tailored-made solution that allows you to define the dose and concentration as well as the assurance that there is no contamination by the red blood cells, which makes it the best value for money!

Quality: Leukocytes free

This brings us to discuss the quality of the PRP according to its content of white blood cells. If everyone agrees that red cells are to be banished, there is currently debate about whether leukocytes are to be preserved or not. Studies are being contradictory for the time being and the only area really concerned is orthopedics. Thus, the study “The differential effects of leukocyte-containing and pure platelet-rich plasma (PRP) on tendon stem/progenitor cells – implications of PRP application for the clinical treatment of tendon injuries” concludes “L-PRP may be detrimental to the healing of injured tendons because it induces catabolic and inflammatory effects on tendon cells and may prolong the effects in healing tendons. On the other hand, when P-PRP is used to treat acutely injured tendons, it may result in the formation of excessive scar tissue due to the strong potential of P-PRP to induce inordinate cellular anabolic effects », which means “Leukocyte-poor PRP can impair the healing of tendons because of inducing catabolic and inflammatory effects on tendon cells and can extend the effects during healing of tendons. However, when using leucocyte-rich PRP, the formation of excess scar tissue can occur due to the strong potential for inducing disorganized anabolic cellular effects”.
It is up to our users to freely harvest the PRP they are interested in, by choosing to eliminate Buffy Coat (which contains almost 100% of the leukocytes) in whole or in part (some retain the upper part of the Buffy Coat to recover 10% more platelets).
No other device can achieve such a performance without sacrificing purity!