结缔组织病相关间质性肺病患者肌炎抗体检测的临床意义

Clinical value of myositis antibodies in patients with connective tissue disease-associated interstitial lung diseases

目的探讨结缔组织病相关间质性肺病(CTD-ILD)患者血清肌炎特异性抗体(MSA)与肌炎相关性抗体(MAA)检测的临床意义.方法回顾性纳入2016年12月至2018年4月南京大学医学院附属鼓楼医院呼吸科就诊的120例住院CTD-ILD患者,其中男37例,女83例,年龄31~76岁,平均(56±11)岁.其中45例多发性肌炎/皮肌炎(PM/DM),36例干燥综合征(SS),39例未分化结缔组织病(UCTD).纳入同期32名非CTD-ILD者为对照组,其中男10名,女22名,年龄21~79岁,平均(42±17)岁.选取保存的患者血清,采用欧蒙免疫印迹膜条方法进行MSA和MAA检测.计算血清MSA和MAA阳性率,分析比较各类CTD-ILD患者抗体分布情况及不同抗体血清阳性者的临床特征.结果120例CTD-ILD患者中,89例MSA和(或)MAA阳性(74.2%),MSA和MAA检出率分别为52.5%(63/120)和61.7%(74/120);非CTD-ILD对照组未检测到肌炎抗体.其中PM/DM-ILD、SS-ILD及UCTD-ILD患者的MSA检出率分别为34/45、12/36、17/39,PM/DM-ILD患者的MSA总检出率明显高于SS-ILD和UCTD-ILD(χ^2=14.53、8.95,P<0.01). MSA中抗合成酶抗体阳性率最高(50/120,41.7%). PM/DM-ILD、SS-ILD及UCTD-ILD患者MAA阳性率分别为29/45、28/36及17/39,抗RO-52抗体阳性率最高(72/120,60.0%),并且与MSA中抗Jo-1抗体等高度相关.结论对于常规自身免疫抗体检测阴性无CTD的ILD患者应进行肌炎抗体谱检测.明确为SS-ILD、UCTD-ILD患者,肌炎抗体谱能检测部分患者有肌炎特异性抗体和肌炎相关性抗体存在,其对临床诊断和治疗的作用有待进一步观察.

Objective To investigate the clinical significance of detection of myositis-specific antibodies (MSAs) and myositis-associated antibodies (MAAs) in patients with connective tissue disease-associated interstitial lung diseases (CTD-ILD). Methods Serum samples of 120 patients with CTD-ILD admitted to the Department of Respiratory, Affiliated Drum Tower Hospital of Nanjing University Medical College from December 2016 to April 2018 were collected for analysis. The patients included 45 with polymyositis/dermatomyositis (PM/DM), 36 with Sjogren′s syndrome (SS) and 39 with undifferentiated connective tissue disease (UCTD). There were 37 males and 83 females with an average age of (56±11) years. Thirty-two patients with non-CTD-ILD, 10 males and 22 females with an average age of (42±17) years, were enrolled as the control group. Euroline Autoimmune Inflammatory Myopathies 16 Ag kit was used for detecting MSAs and MAAs, and the positive rates of serum MSAs and MAAs were calculated. The antibody distribution and clinical characteristics of different groups were analyzed and compared. Results Eighty-nine of the 120 patients with CTD-ILD were positive for MSA and/or MAA (74.2%), and the detection rates of MSAs and MAAs were 52.5%(63/120) and 61.7%(74/120) respectively. No myositis antibody was detected in the non-CTD-ILD group. The detection rates of MSAs in PM/DM-ILD group, SS-ILD group and UCTD-ILD group were 75.6%(34/45), 33.3%(12/36) and 43.6%(17/39) respectively. The total detection rate of MSAs in PM/DM group was significantly higher than that in SS group and UCTD group (χ^2=14.53, 8.95, 0.01). The anti-ARS was the most frequent (50/120, 41.7%). The positive rates of MAAs in the three groups were 64.4%(29/45), 77.8%(28/36),43.6%(17/39) respectively, and anti-Ro-52 accounted for 60%(72/120), and were highly correlated with MSAs such as anti-Jo-1 antibodies. Conclusion Myositis antibody profiling should be performed in patients with ILD who were negative for conventional autoimmune antibody testing and had no CTD. In patients with SS-ILD and UCTD-ILD, the myositis antibody spectrum could detect the presence of myositis-specific antibodies and myositis-related antibodies in some patients, and its role in clinical diagnosis and treatment needed further observation.