目的: 检测CXC趋化因子配体10(CXC motif chemokine 10, CXCL-10)和涎液化糖链抗原6(Krebs von den lungen-6, KL-6)在类风湿关节炎合并肺间质病变(rheumatoid arthritis associated interstitial lung disease, RA-ILD)患者血清中的表达水平，分析其与RA-ILD的相关性，探讨CXCL-10和KL-6对RA-ILD患者病情评价的意义。方法: 选择2021年5月至2023年10月在北京市顺义区医院风湿免疫科住院及门诊治疗的169例类风湿关节炎(rheumatoid arthritis，RA)患者的病例资料进行回顾性分析，根据是否合并ILD分为RA-ILD组82例和RA-non-ILD组87例，根据入排标准最终筛选出两组各80例。采用酶联免疫吸附试验检测所有患者血清CXCL-10和KL-6水平，通过1 ∶ 1倾向性评分匹配法(propensity score matching, PSM)对两组患者进行匹配，得到组间协变量均衡的样本。比较匹配后的组间差异，分析血清CXCL-10、KL-6与ILD评分(Warrick评分)、临床实验室及肺功能参数之间的相关性，利用二元Logistic回归分析RA患者发生ILD的危险因素，并判断CXCL-10、KL-6对RA-ILD的预测价值。结果: 经1 ∶ 1 PSM匹配出RA-ILD组和RA-non-ILD组患者各49例。RA-ILD组血清CXCL-10、KL-6水平显著高于RA-non-ILD组[CXCL-10水平64.36(34.01, 110.18) ng/L vs. 29.80(16.89, 40.55) ng/L，P＜0.001；KL-6水平360.70(236.35, 715.05) U/mL vs. 210.69(159.98, 255.50) U/mL, P＜0.001]。RA-ILD患者血清CXCL-10水平与Warrick评分呈正相关(r=0.378，P=0.007)，与用力肺活量(forced vital capacity, FVC)占正常预计值的百分比(FVC%)呈负相关(r=-0.338，P=0.018)；KL-6与类风湿因子(rheumatoid factor，RF)呈正相关(r=0.296，P=0.039)，与FVC%(r=-0.436，P=0.002)和一氧化碳弥散量(diffusion lung carbon monoxide, DLCO)占预计值的百分比(DLCO%，r=-0.426，P=0.002)呈负相关。单因素和多因素二元Logistic回归分析均提示CXCL-10(OR值分别为1.035、1.023，P均＜0.05)、KL-6水平(OR值分别为1.004、1.005，P均＜0.05)与ILD呈正相关。分别用CXCL-10和KL-6绘制ROC曲线，曲线下面积分别为0.770和0.752，联合检测曲线下面积可增加至0.800。结论: RA-ILD患者血清CXCL-10和KL-6水平明显升高，与ILD患者ILD严重程度有一定的相关性，两者联合检测对诊断RA-ILD有较高的参考价值。

Objective: To detect the serum level of chemokine CXC motif chemokine 10 (CXCL-10) and Krebs von den lungen-6 (KL-6) in patients with rheumatoid arthritis associated interstitial lung disease (RA-ILD), and to analyze their correlation with RA-ILD, as well as the significance in RA-ILD. Methods: A total of 169 RA patients were enrolled in the study. According to imaging findings of with and without ILD in high-resolution computed tomography scans of chest, the subjects were divided into RA-ILD group and RA-non-ILD group. According to the inclusion and exclusion criteria, 80 patients in each of the two groups were finally selected. Two groups were matched according to the 1 ∶ 1 ratio using propensity score matching (PSM). The serum CXCL-10 and KL-6 levels were detected by enzyme-linked immunosorbent assay. The clinical features, laboratory data and medications between the two groups were compared after PSM and the correlation between serum levels and clinical parameters were analyzed. Binary Logistic regression was used to analyze the risk factors of ILD in the RA patients, and the predictive value of CXCL-10 and KL-6 in RA-ILD was evaluated. Results: In this study, 49 patients with RA-ILD and 49 patients with RA-non-ILD were selected by PSM. The levels of CXCL-10 and KL-6 in the RA-ILD group [64.36 (34.01, 110.18) ng/L, 360.70 (236.35, 715.05) U/mL] were significantly higher than those in the RA-non-ILD group [29.80 (16.89, 40.55) ng/L, 210.69 (159.98, 255.50) U/mL] (all P < 0.001). The results of correlation analysis showed that the level of serum CXCL-10 was positively correlated with the Warrick score on chest CT (r=0.378, P=0.007) and negatively correlated with the percentage of forced vital capacity to the predicted value (FVC%, r=-0.338, P=0.018). And the level of KL-6 was positively correlated with rheumatoid factor (RF, r=0.296, P=0.039) and negatively correlated with FVC% (r=-0.436, P=0.002) and the percentage of diffusion capacity for carbon monoxide to the predicted value (DLCO%, r=-0.426, P=0.002). Both univariate and multivariate Logistic regression analysis showed that CXCL-10 and KL-6 were positively correlated with ILD, the values of OR were 1.035 and 1.023 in CXCL-10 and those were 1.004 and 1.005 in KL-6 respectively (P < 0.05). The ROC curves were plotted with CXCL-10 and KL-6. The area under the curve (AUC) was 0.770 and 0.752 respectively. The AUC of combined detection increased to 0.800. Conclusion: Serum levels of CXCL-10 and KL-6 are significantly elevated in patients with RA-ILD and correlated with the severity of ILD. The combined estimate of them helps to improve the effectiveness of diagnosis.