I’m doing a little research for the orthopedic surgeon I work for. She uses platelet-rich plasma treatments for some carefully selected patients. We have recently found out that the lab where the samples are collected is reporting different blood (platelet and white blood cell) counts. I have the task to find out more about this. Is this happening everywhere? Are there any studies to help us investigate this further ourselves?

There was a recent study published from the University of Connecticut that reported platelet-rich plasma differs according to preparation methods and human variability. This isn’t the first study of its kind but the authors do compare their results with other similar studies already published.

The platelet-rich plasma therapy has been around long enough now to start studying it more carefully. Researchers have found that the platelet-rich plasma preparation varies significantly from sample to sample. That means patients aren’t always getting the same amount of platelets and growth factors. This has been shown to be true from one treatment to the next and even from one patient to the next. The question you asked then comes up: why the differences?

To find out, researchers from the University of Connecticut sampled blood from eight people on three separate occasions (baseline or first blood draw, fourteen days later, one month later). Each sample was analyzed for each patient at each of those time periods.

They used three different lab techniques to harvest the platelets: 1) a single-spin technique (referred to as LP), 2) an alternative single-spin method (the HP method, and 3) a double-spin (DS) technique. Each technique is carefully described for the reader including the number of minutes spun and the revolutions per minute.

In all cases, the HP (alternative single-spin separation method) gave the best results with the highest percentage of white blood cells and platelets. The one-step LP method far outperformed the other two methods.

There were clear differences in outcomes not only with the differing techniques used but also for the different times the samples were taken for each individual. The next question naturally arises: why would platelet levels and white blood cell levels vary over time for the same person? The authors suggest age could make a difference. Or there could be a physiologic reason why these variations exist that we just don’t know about yet.

What the study does show is that the method of separation when obtaining platelet-rich plasma makes a difference in the number of white blood cells and platelets collected. Physicians may want to take this fact into consideration when selecting the method used.

For example, it might be helpful to choose the method that matches the intended use of the plasma. One thing to keep in mind is the fact that too many white blood cells can actually cause an overreaction in the tissues.

And too much inflammation at certain points in the healing process may not be a good idea. Perhaps the double spin method would work best. Likewise, there may be times and situations where increased antibacterial and an increased immune response would be helpful. In those cases, the single-spin method might be the most useful.

We hope that helps you get started in exploring this topic. It may be helpful to read this study in addition to the studies mentioned in the article against which they compared their results. You may recognize contributing factors in your own situation based on what these other researchers report.