Correlations of α-melanocyte stimulating hormone levels in serum and synovial fluid with progression of primary knee osteoarthritis / 中华创伤骨科杂志

ABSTRACT

Objective:To explore the correlations of α-melanocyte stimulating hormone ( α-MSH) levels in serum and synovial fluid with progression of primary knee osteoarthritis (KOA). Methods:A retrospective analysis was conducted of the 96 patients who had been diagnosed as primary KOA at Department of Orthopedics, The First Hospital of Huizhou from October 2018 to October 2019. Radiographic severity of KOA was determined by Kellgren-Lawrence (K-L) grades; α-MSH levels were measured by enzyme-linked immunosorbent assay (ELISA). Levels of pro-inflammatory cytokine interleukin-1 β (IL-1 β) and matrix metalloproteinase-3 (MMP-3) were also detected. Another 64 patients with patellar dislocation, matched in age and gender, were enrolled as controls. The Numeric Pain Scale (NPS) and revised Oxford Knee Score (OKS) were employed to evaluate their symptomatic severity. Receiver operating characteristics (ROC) curve was used to compare α-MSH, IL-1 β and MMP-3 with regard to their diagnostic values in the K-L grading. Results:There were no statistically significant difference in age, gender and body mass index between the 2 groups, showing they were comparable ( P> 0.05). The α-MSH levels in synovial fluid were significantly lower in the KOA patients than in the controls [(16.9±3.8) pg/mL versus (18.8±2.7) pg/mL] ( P<0.001); there were no significant differences between the KOA patients and the controls in the serum α-MSH levels [(24.9±1.8) pg/mL versus (24.8±1.7) pg/mL] ( P>0.05). The α-MSH levels in synovial fluid were negatively correlated with K-L grades ( r=-0.382, P<0.001) and negatively correlated with NPS ( r=-0.382, P<0.001) but positively correlated with OKS ( r=0.339, P<0.001). Moreover, the α-MSH levels in synovial fluid were negatively correlated with the IL-1 β levels in synovial fluid ( r=-0.483, P<0.001) and with the MMP-3 levels in synovial fluid ( r=-0.336, P< 0.001). Conclusions:The level of serum α-MSH may not be correlated with the progression of KOA but the synovial fluid α-MSH is negatively correlated with the progression of KOA. Therefore, the expression level of α-MSH in joint synovial fluid can be used as a potential biomarker for assessment of severity of knee osteoarthritis.