Tube centrifugation for processing platelet-rich plasma in the horse

Platelet-rich plasma (PRP) is a popular treatment for equine tendon and ligament injuries; however, commercial PRP systems are expensive. Development of a safe, inexpensive alternative would make PRP therapy more widely available to horse owners. The purpose of this study was to evaluate the quality and bacteriologic safety of PRP produced by three simple, inexpensive tube centrifugation methods and compare the results to a commercial system.

Citrated blood collected from 26 normal horses was processed by four methods: blood collection tubes centrifuged at 1200 and 2000 x g, a 50ml conical tube, and a commercial system. Platelet and cell counts and mean platelet volume (MPV) in whole blood and PRP were determined using an automated hematology analyzer. Results were analyzed using mixed model ANOVA with post-hoc comparisons (MPV and fold change for RBC, WBC, and platelets) and binary logistic generalized estimating equations with horse as a blocking factor (absolute numbers of WBC, and platelets). Aerobic and anaerobic cultures were performed. Significance was set at p<0.05.

Mean platelet concentrations ranged from 1.55 to 2.58 fold. The conical tube method produced the highest number of PRP samples with platelet concentrations of greater than 2.5-fold and within the clinically acceptable range of >250,000 platelets/?l. WBC counts were lowest using the commercial system and unacceptably high using the red top methods. The incidence of bacterial contamination was low (2.1%). Based on these results, the conical tube method may be a suitable alternative to commercial PRP systems in cases with budgetary constraints.