Department of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
J Clin Lab Anal. 2019 Oct;33(8):e22978. doi: 10.1002/jcla.22978. Epub 2019 Jul 13.
This study aimed to investigate the clinical significance of Krebs von den Lungen-6 (KL-6) serum levels in patients with anti-MDA5 antibody-positive dermatomyositis (anti-MDA5 DM) having interstitial lung disease (ILD), especially in the amyopathic DM phenotype.
The serum KL-6 level was measured using a chemiluminescence enzyme immunoassay (CLEIA) in patients with anti-MDA5 DM, including clinically amyopathic dermatomyositis (CADM)-ILD and classic DM-ILD, and healthy donors. The baseline and post-treatment serum KL-6 levels were determined in 39 patients with CADM-ILD who experienced remission or acute exacerbation. The association between laboratory findings, high-resolution computed tomography (HRCT) scores, pulmonary function tests (PFTs), and the predictive value of baseline KL-6 level for death was analyzed.
The serum KL-6 levels were significantly higher in patients with CADM-ILD (1339 ± 1329 U/mL) compared with DM-ILD (642.3 ± 498.4 U/mL) and healthy donors (162.4 ± 54.01 U/mL). The KL-6 levels correlated positively with chest HRCT scores, serum lactate dehydrogenase, serum ferritin levels, and PFTs, but not with erythrocyte sedimentation rate. During follow-up, the post-treatment serum KL-6 levels significantly reduced in the remission/stable group, but increased in the acute exacerbation group. Higher levels of ferritin and KL-6 and HRCT scores were independently associated with poor prognosis. The 1-year survival rate was significantly lower in patients with high KL-6 level than in those with low KL-6 level.
The serum KL-6 levels may be a useful marker for predicting and monitoring ILD in Chinese patients with anti-MDA5 DM, especially amyopathic DM phenotype.
本研究旨在探讨抗 MDA5 抗体阳性皮肌炎（抗 MDA5 DM）合并间质性肺病（ILD）患者，尤其是无肌病性皮肌炎（CADM）表型患者血清 Krebs von den Lungen-6（KL-6）水平的临床意义。
采用化学发光酶免疫分析法（CLEIA）检测抗 MDA5 DM 患者，包括临床无肌病性皮肌炎（CADM）-ILD 和经典皮肌炎（DM）-ILD 患者，以及健康对照者的血清 KL-6 水平。对 39 例 CADM-ILD 患者的缓解或急性加重期的基线和治疗后血清 KL-6 水平进行检测。分析实验室检查、高分辨率计算机断层扫描（HRCT）评分、肺功能检查（PFT）与 KL-6 水平的相关性，以及基线 KL-6 水平对死亡的预测价值。
CADM-ILD 患者的血清 KL-6 水平（1339±1329 U/mL）明显高于 DM-ILD 患者（642.3±498.4 U/mL）和健康对照者（162.4±54.01 U/mL）。KL-6 水平与胸部 HRCT 评分、血清乳酸脱氢酶、血清铁蛋白和 PFT 呈正相关，而与红细胞沉降率无关。在随访期间，缓解/稳定组的治疗后血清 KL-6 水平显著降低，而急性加重组的水平升高。更高的铁蛋白和 KL-6 水平以及 HRCT 评分与不良预后独立相关。KL-6 水平较高的患者 1 年生存率明显低于 KL-6 水平较低的患者。
血清 KL-6 水平可能是预测和监测中国抗 MDA5 DM 患者 ILD 的有用标志物，尤其是 CADM 表型。
