原发性膝骨关节炎患者血浆cf-DNA/NETs 的检测水平及临床意义

目的　通过检测原发性膝骨关节炎（knee osteoarthritis，KOA）患者血浆中游离脱氧核糖核酸（circulating freeDNA，cf-DNA）/ 中性粒细胞胞外诱捕网（neutrophil extracellular traps，NETs）水平，分析其与病情严重程度及原发性KOA 发病的关系。方法　选取空军军医大学西京医院2020 年3 月～ 2021 年8 月收治的192 例原发性KOA 患者作为观察组，200 例体检健康人群作为对照组。检测两组受试者血浆cf-DNA/NETs 水平；采用凯尔格伦- 劳伦斯（Kellgren-Lawrence，K-L）分级标准将观察组分为四个亚组:原发性KOA Ⅰ组（n=39）、原发性KOA Ⅱ组（n=57）、原发性KOA Ⅲ组（n=63）和原发性KOA Ⅳ组（n=33）；采用西安大略和麦克马斯特大学骨关节炎指数（Western Ontario andMcMaster University Osteoarthritis Index，WOMAC）量表评估原发性KOA 患者病情严重程度；Pearson 分析观察组血浆cf-DNA/NETs 水平与K-L 分级、WOMAC 评分的相关性；Logistic 回归分析影响原发性KOA 发病的相关因素。结果　观察组血浆cf-DNA/NETs 水平高于对照组（932.94±106.66 ng/ml vs 86.52±16.25 ng/ml），差异有统计学意义（t=110.901，P =0.000）；原发性KOA Ⅰ组、原发性KOA Ⅱ组、原发性KOA Ⅲ组和原发性KOA Ⅳ组血浆cf-DNA/NETs 水平依次升高（836.54±93.18 ng/ml，905.29±94.46 ng/ml，950.33±117.85 ng/ml 和1 061.40±122.29 ng/ml），差异有统计学意义（F=28.011，P=0.000）。观察组血浆cf-DNA/NETs 水平与K-L 分级、关节功能评分均呈正相关（r=0.552 ，0.627，均P=0.000）。年龄（OR=1.936, 95%CI:1.273~2.945）、吸烟史（OR=1.853, 95%CI:1.158~2.966）、家族遗传史（OR=1.997,95%CI:1.336~2.935）和血浆cf-DNA/NETs 水平（OR=2.104, 95%CI:1.441~3.071）均是原发性KOA 发病的危险因素（P=0.002，0.010，0.001，0.000）。结论　原发性KOA 患者血浆cf-DNA/NETs 呈高表达，血浆cf-DNA/NETs 与原发性KOA 的发生及病情发展密切相关。检测其水平可为原发性KOA 的预防及治疗提供参考依据。

Detection Level and Clinical Significance of Plasma cf-DNA/NETs in Patients with Primary Knee Osteoarthritis

Objective　To test the level of circulating free DNA/neutrophil extracellular traps (cf-DNA/NETs) in plasma of patients with primary knee osteoarthritis (KOA), and analyze the relationship between it and the severity of the disease and the morbidity of primary KOA. Methods　192 patients with primary KOA treated in Xijing Hospital of Air Force Military Medical University from March 2020 to August 2021 were selected as the observation group and 200 healthy people as the control group. The plasma cf-DNA/NETs levels of the two groups were measured. The observation group was divided into four subgroups according to Kelgren Lawrence (K- L) classification standard: primary KOA Ⅰ group (n=39), primary KOA Ⅱ group (n=57), primary KOA Ⅲ group (n=63) and primary KOA Ⅳ group (n=33). Western Ontario and McMaster University Osteoarthritis Index (WOMAC) was used to evaluate the severity of primary KOA patients.Pearson analysis was used to analyze the correlations between plasma cf-DNA/NETs level and K-L grade, WOMAC score of the observation group，and Logistic regression analysis was used to analyze the related factors affecting the incidence of primary KOA. Results　The level of plasma cf-DNA/NETs in the observation group was higher than control group (932.94±106.66 ng/ml vs 86.52±16.25 ng/ml)，the difference was statistically significant(t=110.901, P=0.000). The level of plasma cf-DNA/NETs in primary KOA Ⅰ group, primary KOA Ⅱ group, primary KOA Ⅲ group and primary KOA Ⅳ group increased in turn (836.54±93.18 ng/ml, 905.29±94.46 ng/ml, 950.33±117.85 ng/ml, 1 061.40±122.29 ng/ml) ，the difference was statistically significant (F=28.011,P=0.000). The level of plasma cf-DNA/NETs was positively correlated with K-L grade and joint function score in observation group (r =0.552，0.627, all P =0.000). Age（OR=1.936, 95%CI:1.273~2.945）, smoking history（OR=1.853, 95%CI:1.158~2.966）, family genetic history（OR=1.997, 95%CI:1.336~2.935） and plasma cf-DNA/NETs level（OR=2.104, 95%CI:1.441~3.071） were all risk factors for primary KOA (P=0.002, 0.010, 0.001, 0.000). Conclusion　Plasma cf-DNA/ NETs was highly expressed in patients with primary KOA, plasma cf-DNA/NETs was closely related to the occurrence and development of primary KOA.Detecting its level may provide a reference basis for the prevention and treatment of primary KOA.