[The role of autoantibodies in myositis associated interstitial lung disease].

Myositis-associated interstitial lung disease (M-ILD) is a heterogeneous group of diseases. It can be divided into different subtypes listed below according to different myositis antibodies. (1) ASS-related ILD responds well to glucocorticoid plus immunosuppressant therapy but tends to relapse. (2) Anti-MDA5-related ILD is the worst prognosis of M-ILD with high mortality rate, and most patients die within the first 6 months of the disease course. (3) Non-MDA-5 DM-associated ILD is often mild, and NSIP is the main HRCT pattern. (4) IMNM-associated ILD shows mild clinical symptoms of ILD in majority of the case, and NSIP is also the main HRCT pattern. (5) With MAA-associated ILD, anti-Ku-positive patients are more common complicated with ILD. In addition, the changes of serum levels of myositis antibody are generally positively correlated with disease activity, and titer drop after disease remission. Therefore, myositis antibodies are important immunological biomarkers for clinical typing and prognosis of M-ILD.肌炎相关间质性肺疾病（M-ILD）是一组异质性疾病，可根据肌炎抗体的不同分为以下5种类型：（1）抗合成酶综合征（ASS）相关ILD，这类患者对糖皮质激素（简称激素）联合免疫抑制剂治疗反应良好，但激素减量后易复发；（2）抗MDA5相关的ILD，这是预后最差的一类M-ILD，病死率高，且大部分患者死亡发生在病程的前6个月；（3）非抗MDA-5型皮肌炎相关的ILD，病情常较轻，以非特异性间质性肺炎（NSIP）型多见；（4）免疫介导坏死性肌病相关的ILD，大多数患者ILD的临床症状轻微或无明显的肺部症状，HRCT也以NSIP为主；（5）肌炎相关性自身抗体相关的ILD，其中抗Ku阳性者伴发ILD常见。另外，肌炎抗体滴度的变化一般与疾病活动度呈正相关，当疾病缓解后滴度下降。因此，肌炎抗体是M-ILD临床分型和判断预后的重要免疫学指标。.