Platelet-rich plasma shows beneficial effects for patients with knee osteoarthritis by suppressing inflammatory factors

Abstract

Knee osteoarthritis is a degenerative disease that may develop due ageing, obesity, strain, congenital abnormal joints, joint deformity or trauma. It is caused by many factors, such as degradation of articular cartilage injury, joint edge and subchondral bone hyperplasia of reactivity. Platelet-rich plasma (PRP) is an autologous blood sample that contains highly concentrated platelets and multiple cell growth factors. PRP promotes synovial cell proliferation and differentiation and may recover cartilage morphology. In the present study, the clinical efficacy of PRP was investigated in patients with knee osteoarthritis aged between 18 and 30 years in a phase-III clinical study. Following an 8-week baseline, patients with knee osteoarthritis were randomized into once-weekly, double-blind treatment with PRP (2-14 ml) or placebo groups. The results indicated that patients with osteoarthritis treated with PRP had modulated plasma concentrations of inflammatory factors and pro-angiogenic factors compared with the placebo group. Treatment responses were assessed by median percent reduction in inflammatory and pro-angiogenic factors and these improved with PRP treatment compared with the placebo. Clinical data indicated that PRP alleviated knee osteoarthritis and reduced humoral and cellular immune responses that led to beneficial effects on histological parameters. Inflammation was significantly alleviated in patients receiving PRP compared with the placebo group. The most common treatment-emergent adverse events in the presence of PRP were hypertension and proteinuria. In conclusion, treatment with PRP for patients with knee osteoarthritis presented beneficial effects in alleviating joint inflammation, cartilage destruction and bone damage, and repairing joint tissue. These results suggested that PRP may be a potential therapeutic agent for knee osteoarthritis.

Keywords: angiogenesis; inflammation; knee osteoarthritis; platelet-rich plasma.

Figures

Figure 1.

Response rate and median reduction of score for patients with knee osteoarthritis after treatment with PRP or placebo. (A) Response rate of patients with knee osteoarthritis during the treatment period. (B) Median reduction of score for patients with knee osteoarthritis 8 weeks from the baseline over double-blind period. Data are presented as the mean + standard error of the mean. *P

Figure 2.

Pharmacokinetic analysis of PRP in patients with knee osteoarthritis. (A) Plasma concentrations of PRP with increasing dose. (B) Plasma concentrations of PRP (10 ml) from 0–36 h post-treatment. Hodges-Lehmann estimates of median drug treatment effect and 95% confidence intervals are provided. Data are presented as the mean ± standard error of the mean. AUC, area under the curve; PRP, platelet-rich plasma.

Figure 3.

Inflammatory and pro-angiogenic factors in patients with knee osteoarthritis after treatment with PRP (10 ml) or placebo. (A) Plasma concentrations of IL-17A, IL-1β, TNF-α, RANKL, IL-6 and IFN-γ after an 8-week observation. (B) Plasma concentration of HGF, ICAM-1, OPN, PD-ECGF, VEGF, PDGF, IGF-1 and TGF-β after an 8-week observation. Data are presented as the mean + standard error of the mean. **P

Figure 4.

Analysis of joint inflammation and synovial proliferation in patients with knee osteoarthritis after treatment with PRP or placebo. (A) Effect of PRP treatment on joint inflammation in patients with knee osteoarthritis. (B) Effect of PRP treatment on synovial degeneration in patients with knee osteoarthritis. All patients underwent an 8-week maintenance period by injection of PRP (10 ml). Data are presented as the mean + standard error of the mean. ***P

Figure 5.

Analysis of neovascularization and the damaged area in synovial grafts in patients with knee osteoarthritis after treatment with PRP or placebo. (A) Destruction of the cartilage and neovascularization analysis after treatment with PRP or placebo. (B) Histological analysis of synovial damaged area after treatment with PRP or placebo. Data are presented as the mean + standard error of the mean. ***P