Decreased Levels of Synovial Fluid Biomarkers Correlate with the Severity and Function of Patients with Osteoarthritis Following Electroacupuncture

Abstract Objective To investigate the expression of inflammatory factors IL-6, IL-8, MMP-1, and MMP-3 in the synovial fluid (SF) of patients with osteoarthritis (OA) during electroacupuncture treatment, and further analyze the correlation between inflammatory factors and the function of patients and the severity of osteoarthritis. Methods 137 patients with knee osteoarthritis (KOA) were collected. 128 patients were eventually enrolled in the study after propensity matching analysis, including 64 patients in the electroacupuncture group and 64 patients in the control group. K-L grading was performed according to X-rays. The patients in the control group were treated with conventional physical rehabilitation therapy. The patients in the electroacupuncture group were treated with 6 weeks of electroacupuncture and conventional physical rehabilitation therapy. The visual analog score (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and Lysholm knee score were compared at three time points: before treatment, 6 weeks after treatment, and 6 months after treatment. The levels of SF inflammatory factors IL-6, IL-8, MMP-1, and MMP-3 were analyzed in both groups at three time points to investigate the correlation between inflammatory factors and functional scores and K-L classification. Results The VAS, WOMAC, and Lysholm scores of patients in both groups improved significantly after treatment (P < 0.05). The electroacupuncture group showed a significant reduction in VAS compared to the control group at 6 weeks and 6 months after treatment (P < 0.05). WOMAC scores were significantly lower in the electroacupuncture group compared to the control group at 6 months post-treatment (P < 0.05). Lysholm scores were significantly higher in the electroacupuncture group compared to the control group at 6 weeks and 6 months post-treatment (P < 0.05). The levels of all inflammatory factors decreased significantly in both groups after treatment. The levels of IL-6, IL-8, and MMP-3 were significantly lower in the electroacupuncture group compared with the control group at 6 weeks and 6 months after treatment (P < 0.05). The level of IL-6 was positively correlated with VAS scores (r = 0.45, p < 0.001) and WOMAC (r = 0.3, p < 0.001), and negatively correlated with Lysholm score (r=-0.27, p < 0.001) and K-L classification (r=- 0.54, p < 0.001).The level of IL-8 was positively correlated with VAS (r = 0.32, p < 0.001) and negatively correlated with Lysholm score (r=-0.19, p < 0.0027). The level of MMP-3 was positively correlated with WOMAC score (r = 0.48, p < 0.001). The level of MMP-1 was negatively correlated with K-L classification (r =-0.29, p < 0.001). Conclusion IL-6 in SF was associated with pain, impaired function, and the severity of OA. MMP-3 is associated with the severity of OA. IL-6 and MMP-3 are expected to be used as a biomarker for diagnosis, treatment, and determining the prognosis and severity of OA. Electroacupuncture can effectively relieve pain and enhance articular function in patients with KOA. It is a safe and effective method for treating KOA. SF inflammatory factor levels in patients with KOA decreased significantly after electroacupuncture treatment. Electroacupuncture treatment may work by anti-inflammatory effect.