Summary

The final composition of PRP (platelet count) was significantly influenced by patient’s age and baseline blood platelet count. This study raises awareness regarding the potential need for quality release criteria to assess baseline blood and/or final PRP composition when using PRP in routine clinical practice.

Abstract

Background

There is a lack of studies in the literature evaluating the variability in the final composition of platelet rich plasma (PRP) based on the patient’s demographics and baseline blood count.

Purpose

(1) To evaluate the effect of age, sex, body mass index (BMI) and baseline blood count on the final composition of PRP; and (2) To evaluate the variability of PRP applied in the same patient at two different timepoints.

Methods

A total of 403 PRP injections from 357 patients were analyzed from an institutional prospective registry of PRP between January 2019 and December 2021. Patient demographics were recorded as well as baseline blood count of all patients treated with PRP for a musculoskeletal condition. In addition, the final concentration of platelets, leukocytes, and erythrocytes of the PRP prepared for each patient was quantified. The influence of sex, gender, BMI, age, and baseline blood count on final platelet concentrations in PRP was evaluated. In addition, to evaluate intrapersonal variability, the first dose of PRP platelet counts was compared to the second dose of PRP platelet counts between 34 patients who received two doses of PRP.

Results

A directly proportional variation in PRP platelet count of 3.8X was observed for each unit increase in baseline blood platelet count. For every decade increase, we observed an approximate decrease of 32,666 platelets. When the first dose of PRP platelet counts was compared to the second dose of PRP platelet counts between the same patients, significant differences were found. A mean of 890,018 platelets in the first PRP and a mean of 1,244,467 in the second PRP with a mean difference of 354,448 was found (p 0.008). We did not find differences in the final concentration of platelets regarding sex, BMI, or PRP protocol.

Conclusions

Overall the final composition of PRP (platelet count) was significantly influenced by patient’s age and baseline blood platelet count. In contrast, BMI, gender and the rest of the components of the baseline blood count did not have a significant influence on final PRP. Furthermore, in patients who received two doses of PRP, the final concentration of platelets varied significantly between the two preparations. This study raises awareness regarding the potential need for quality release criteria to assess baseline blood and/or final PRP composition when using PRP in routine clinical practice.

Level of Evidence: II Prospective cohort study