类风湿关节炎患者血清及滑液中DNase Ⅰ活性检测及与炎症的相关性

Correlation of DNase Ⅰ in serum and synovial fluid with inflammatory activity in patients with rheumatoid arthritis

目的探讨脱氧核糖核酸酶Ⅰ(DNaseⅠ)在类风湿关节炎中潜在的致病作用。方法辐射状酶扩散法测定83例类风湿关节炎(RA)患者和60名健康对照者血清DNaseⅠ活性以及27例RA患者和38例其他炎症性关节炎患者滑液(SF)DNaseⅠ活性,Pico Green试剂盒测定游离DNA(cf DNA)水平,并分析两者与RA患者临床指标的相关性。结果 RA组血清DNaseⅠ活性显著低于健康对照组[(0.3065±0.1436)U/m L vs(0.4289±0.1976)U/m L,P<0.001];血清DNaseⅠ活性与ESR(r=-0.2862,P=0.0122)、CRP(r=-0.2790,P=0.0184)和中性粒细胞计数(r=-0.287,P=0.011)呈负相关。SF DNaseⅠ活性在RA、强直性脊柱炎组和痛风性关节炎组中几乎都是阴性的。RA组患者SF cf DNA水平明显高于骨性关节炎组患者[(100.81±142.98)μg/m L vs(18.98±31.40)μg/m L,P=0.002];与强直性脊柱炎组(45.85±47.67μg/m L,P=0.428)和痛风性关节炎组(162.95±97.49μg/m L,P=0.132)无显著性差异;炎症性关节炎患者SF cf DNA水平与ESR(r=0.4106,P=0.0116)和CRP(r=0.5747,P=0.0002)呈显著正相关。结论 DNase I活性受损可能是中性粒细胞胞外网状陷阱形成增强的原因并在RA发病机制中起作用。

Objective To investigate the potential role of deoxyribonuclease Ⅰ （DNase Ⅰ） in the pathogenesis of rheumatoid arthritis （RA）. Methods DNase Ⅰ activity was measured by radial enzyme-diffusion method in serum samples from 83 RA patients and 60 healthy volunteers and in the synovial fluid （SF） from 27 RA patients and 38 patients with other inflammatory arthritis. SF cfDNA level was measured with Pico Green Kit, and the correlation among DNase I activity, cfDNA level and clinical parameters of RA patients was analyzed. Results Serum DNase I activity was significantly lower in RA patients than in the healthy control subjects （0.3065±0.1436 vs 0.4289±0.1976 U/mL, P〈0.001）, and was negatively correlated with ESR （r=-0.2862, P=0.0122）, CRP （r=-0.2790, P=0.0184） and neutrophil cell counts （r=-0.287, P=0.011）. SF DNase I activity was almost negative in patients with RA, ankylosing spondylitis （AS） and gouty arthritis （GA）. SF cfDNA level in RA patients was significantly higher than that in patients with osteoarthritis （100.81 ± 142.98 vs 18.98 ± 31.40μg/mL, P=0.002）, but similar to that in patients with AS （45.85 ± 47.67μg/mL, P=0.428） and GA （162.95 ± 97.49μg/mL, P=0.132）. In patients with inflammatory arthritis, SF cfDNA level was positively correlated with ESR （r=0.4106, P=0.0116） and CRP （r=0.5747, P=0.0002）. Conclusion Impairment of DNase I activity may be responsible for the enhanced NETs generation and plays a role in the pathogenesis of RA.