Effect of whole blood platelet concentration on platelet-rich plasma platelet concentration

Summary: Abstract Body: Platelet-rich plasma (PRP) is an autologous blood product consisting of mostly platelets created from the centrifugation of whole blood (WB). One may intuitively assume that the concentration of platelets in PRP would vary based on the concentration of platelets WB drawn at the time of preparation, but validating this assumption is important for conducting research on PRP. The aim of this study is to compare the WB platelet concentration (WBP) to the corresponding PRP platelet concentration (PRPp). This single academic center retrospective study used data from an alopecia specialty clinic. WB volume pre-centrifugation, WBp, PRP volume post-preparation, and PRPp were assessed from quality control blood specimens. As some patients had multiple PRP treatments, a linear mixed-effects model was used to compare WBp to PRPp at each visit. Two PRP preparation devices (A and B) were modeled independently to evaluate the association between WBp and PRPp while controlling for repeated measures and the ratio of WB to PRP volume collected for α=.05. Box-Cox transformation was applied to both models due to violation of normality. Forty-three treatments were excluded due to missing data, leaving 124 treatments using device A and 131 using device B in 67 patients for analysis. An average of 20.3 ml of WB and 8.5 ml of PRP was collected each visit. There was a statistically significant correlation between WBp and PRPp for both device A (β’=0.018,P= .005) and device B (β’=0.007,P= .013). The results of this study support an association between the WBp and PRPp, although the impact of WBp varied between devices. Most patients in the dataset used had WBp between 150,000 to 400,000 platelets/ml, it is unclear how well the model extrapolates to values outside this range. These results may assist providers in making clinical decisions for using PRP in patients with low-normal WB platelet concentrations. Future studies are planned to assess the effect PRPp on PRP efficacy. John Meisenheimer¹, Maria Teachout¹, Javed Shaik¹, Ronda Farah¹, Kim T. Nguyen¹, Ora Raymond¹, Nathalie Ly¹, Sophia Fruechte¹, Briana Paiewonsky¹, Mikhail Usovich¹, Maria Hordinsky¹ 1. Department of Dermatology, University of Minnesota Twin Cities, Minneapolis, MN, United States. Translational Studies: Cell and Molecular Biology