皮肌炎/临床无肌病性皮肌炎患者血清中CADM-140抗体的检测和临床意义

目的 对皮肌炎（DM）/临床无肌病性皮肌炎（CADM）患者进行CADM-140抗体检测，探讨CADM-140抗体与临床特征间的联系。方法 采集38例DM（22例）/CADM（16例）患者血清，另外采集46例伴有肺间质病变的其他结缔组织病患者血清，包括8例多发性肌炎、15例系统性红斑狼疮、5例系统性硬化病、6例干燥综合征、6例混合性结缔组织病、6例特发性肺纤维化和5例正常对照者。以重组黑素瘤分化相关基因5（rMDA-5）为底物，通过ELISA检测患者血清中CADM-140抗体，比较CADM-140抗体阳性与阴性患者的临床特征。 结果 ①16例CADM和22例DM患者血清CADM-140抗体阳性例数分别为7例和2例，CADM患者阳性率（43.8%）显著高于DM（9.1%）（P ＜ 0.05），46例伴有肺间质病变的其他结缔组织病患者及5例正常人均阴性；②CADM-140抗体阳性患者皮肤溃疡和坏死的发生率为8/9，红细胞沉降率为（40.8 ± 23.1） mm/1 h，CADM-140抗体阴性组分别为6.9%和（22.5 ± 16.8） mm/1 h，两组比较，P ＜ 0.01和 ＜ 0.05；CADM-140抗体阳性患者乳酸脱氢酶水平显著高于阴性组（分别为328.3 ± 104.2和241.1 ± 100.3 IU/L，P ＜ 0.05），而肌酸激酶显著低于阴性组（分别为156.3 ± 260.8和1806.2 ± 3737.1 IU/L，P ＜ 0.05）；两组间抗核抗体阳性率和恶性肿瘤发生率的差异无统计学意义；③CADM-140抗体阳性患者不仅肺间质病变发生率显著高于阴性组（分别为9/9和48.3%，P ＜ 0.01），而且急进型肺间质病变发生率也显著高于阴性组（分别为5/9和0，P ＜ 0.05）。阳性组肺高分辨率CT评分（122.9 ± 54.8）显著高于阴性组（70.0 ± 59.8）（P ＜ 0.05）。结论 通过检测CADM-140抗体不仅可以判断DM/CADM是否合并肺间质病变，还可能是伴发急进型肺间质病变的血清学标记，动态观察血清CADM-140抗体水平也许有助于预测肺间质病变病程。

Detection of anti-CADM-140 antibody in patients with dermatomyositis or clinically amyopathic dermatomyositis and its clinical significance

Objective To detect anti-clinically amyopathic dermatomyositis (CADM)-140 antibody in patients with dermatomyositis (DM) or CADM,and to estimate its clinical correlation.Methods Serum samples were collected from 22 patients with DM,16 patients with CADM,46 patients with other connective tissue diseases complicated by interstitial lung disease(including 8 cases of polymyositis,15 cases of systemic lupus erythematosus,5 cases of systemic sclerosis,6 cases of Sj(o)gren syndrome,6 cases of mixed connective tissue disease,6 cases of idiopathic pulmonary fibrosis),and 5 normal human controls.Enzyme-linked immunosorbent assay (ELISA) was performed with the recombinant melanoma differentiation-associated gene 5(rMDA)as a substrate to measure the anti-CADM-140 antibody in these serum samples.Clinical manifestations were compared between patients with anti-CADM-140 antibody and those without.Results The anti-CADM-140antibody was found in 43.8% (7/16) of patients with CADM and 9.1%(2/22) of patients with DM(P<0.05),but absent in the patients with other connective tissue diseases and in the normal human controls.A significant incroase was observed in anti-CADM-140 antibody-positive patients with DM/CADM in the incidence of cutaneous ulceration and necrosis,interstitial lung disease and rapidly progressive interstitial lung disease (8/9 vs.6.9%,P<0.01;9/9 vs.48.3%,P<0.01;5/9 vs.0,P<0.05),serum lactate dehydrogenase level(328.3±104.2 vs 241.1±100.3 IU/L P<0.05),erythrocyte sedimentation rate(40.8±23.1 vs.22.5±16.8 mm/1 h,P<0.05),high resolution computed tomography score(122.9±54.8 vs.70.0±59.8,P<0.05)compared with anti-CADM-140 antibody-negative patients with DM/CADM.The ereatine kinase level was significantly lower(156.3±260.8 vs.1806.2±3737.1 IU/L P<0.05)in anti-CADM-140 antibody-positive patients with DM/CADM than in anti-CADM-140 antibody-negative patients with DM/CADM,while no significant difference was noted in the positivity rate of antinuclear antibodies or incidence of malignancies between the antibody-positive and-negative patients with DM/CADM.Conclusions Anti-CADM.140 antibody not only is useful for the diagnosis of interstitial lung disease in patients with DM/CADM,but also may serve as a serum marker for rapidly progressive interstitial lung disease.Monitoring of serum anti-CADM-140 antibody might help to predict the progression of interstitial lung disease in patients with DM/CADM.