Quality comparison between two different types of platelet-rich plasma for knee osteoarthritis

Knee osteoarthritis (KOA), the most common form of osteoarthritis (OA) is a considerable health concern worldwide. Platelet-rich plasma (PRP) is a common therapeutic option for KOA. Different types of PRPs have varying efficacies. However, a comparative analysis of the qualities of these PRPs is lacking.

Two types of PRPs, including autologous protein solution (APS), and leukocyte-poor PRP (LP-PRP) along with whole blood (WB) and platelet-poor plasma (PPP) were characterized for platelet content, leukocyte content, and composition in 10 healthy volunteers (HV) (the controlled laboratory study) and 16 KOA patients (a retrospective observational study). Additionally, the levels of the platelet-derived growth factor (PDGF)-BB, and different cytokines were estimated in HV.

In HV, the concentrations of platelets and leukocytes, levels of different cytokines, including interleukin 1 receptor antagonist (IL-1Ra), soluble TNF receptor type II (sTNF-RII), and IL-1β, and the ratio of IL-1Ra/IL-1β were significantly higher in APS, whereas the PDGF-BB was higher in LP-PRP than APS. In KOA patients, a higher concentration of platelets was observed in LP-PRP, and a higher concentration of leukocytes was observed in APS than LP-PRP. Following the PAW classification system, LP-PRP was classified as P2-B type in HV (51.3 × 10⁴/μl) and KOA (53.4 × 10⁴/μl), whereas APS was classified as P3-A type in HV (110.1 × 10⁴/μl) and P2-A type in KOA (29.0 × 10⁴/μl). In a retrospective observational study, the KOA patients who underwent APS injection had a higher incidence of arthralgia, and this arthralgia lasted for a longer time than LP-PRP injection in the same individual.

The quality of the two PRPs differed distinctively depending on their preparation methods, which might affect their clinical efficacies and adverse events. Therefore, the characterization of these parameters should be prioritized while choosing PRP.