Gan Y Z, Li Y H, Zhang L H, Ma L, He W W, Jin Y B, An Y, Li Z G, Ye H
Department of Rheumatology & Immunology, Peking University People's Hospital, Beijing 100044, China.
Department of Rheumatology, Hulunbeier People's Hospital, Hulunbeier 021008, Inner Mongolia, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2020 Dec 18;52(6):1001-1008. doi: 10.19723/j.issn.1671-167X.2020.06.003.
To study the differences between clinically amyopathic dermatomyositis (CADM) and typical dermatomyositis (DM) on clinical and immunological features.
By collecting clinical data of 106 CADM patients and 158 DM patients from January 2010 to June 2019 in the department of Rheumatology and Immunology, Peking University People's Hospital, the clinical characteristics and immunological features in the two groups were compared, and the distribution characters and the clinical meanings of myositis autoantibodies were discussed in the two groups respectively. Myositis autoantibodies were measured by immunoblotting according to the manufacturers' instructions.
In the aspects of clinical manifestations, CADM presented more with onset of interstial lung diseases (ILD) compared with DM (20.7% . 7.6%, =0.002), and CADM-ILD was more likely to be acute ILD (58.3% . 26%, < 0.001), and there were no differences between CADM and DM in cutaneous manifestations, accompanied with connective tissue disease (CTD) and malignancy. In CADM, the positive rate of rheumatoid factors and antinuclear antibodies was lower in DM. The most common myositis specific autoantibodies (MSAs) in CADM were anti-MDA5 (36%), anti-PL-7 (11.2%) and anti-TIF-1γ (10.1%). The most common MSAs in DM were anti-Jo-1 (19.2%), anti-TIF-1γ (11.5%) and anti-MDA5 (11.5%). Anti-MDA5 was correlated with acute ILD and skin ulceration both in CADM and DM; in CADM, skin ulceration was not associated with the titer of anti-MDA5; while in DM, skin ulceration was associated with high titer of anti-MDA5. In DM, anti-TIF-1γ was correlated with heliotrope eruption, V/shawl neck sign, perionychia erythma and malignancy, and higher rate of malignancy was seen in all titers of the anti-TIF-1γ positive patients. In CADM, anti-TIF1-γ showed no correlation with clinical manifestations. The most common myositis associated autoantibody was anti-Ro-52 both in CADM and DM. In CADM, anti-Ro-52 was associated with Raynaud's phenomenon and chronic ILD, while in DM, anti-Ro-52 was associated with mechanic's hands, noninfectious fever and accompanied CTD.
Compared with DM, ILD is more likely to be acute in CADM. It is different between CADM and DM about the distribution of myositis autoantibodies and the clinical significance of the same myositis antibody, and the clinical significance of some myositis antibodies is related to titers.
研究临床无肌病性皮肌炎（CADM）与典型皮肌炎（DM）在临床及免疫学特征上的差异。
收集2010年1月至2019年6月北京大学人民医院风湿免疫科106例CADM患者和158例DM患者的临床资料，比较两组的临床特征及免疫学特征，并分别探讨两组肌炎自身抗体的分布特点及临床意义。按照制造商说明书采用免疫印迹法检测肌炎自身抗体。
在临床表现方面，与DM相比，CADM更多表现为间质性肺疾病（ILD）起病（20.7% 对7.6%，P = 0.002），且CADM-ILD更易为急性ILD（58.3% 对26%，P < 0.001），CADM与DM在皮肤表现、合并结缔组织病（CTD）及恶性肿瘤方面无差异。在CADM中，类风湿因子和抗核抗体的阳性率低于DM。CADM中最常见的肌炎特异性自身抗体（MSAs）为抗MDA5（36%）、抗PL-7（11.2%）和抗TIF-1γ（10.1%）。DM中最常见的MSAs为抗Jo-1（19.2%）、抗TIF-1γ（11.5%）和抗MDA5（11.5%）。抗MDA5在CADM和DM中均与急性ILD及皮肤溃疡相关；在CADM中，皮肤溃疡与抗MDA5滴度无关；而在DM中，皮肤溃疡与抗MDA5高滴度相关。在DM中，抗TIF-1γ与向阳疹、V字领/披肩征、甲周红斑及恶性肿瘤相关，抗TIF-1γ阳性各滴度患者的恶性肿瘤发生率均较高。在CADM中，抗TIF1-γ与临床表现无相关性。CADM和DM中最常见的肌炎相关自身抗体均为抗Ro-52。在CADM中，抗Ro-52与雷诺现象及慢性ILD相关，而在DM中，抗Ro-52与技工手、非感染性发热及合并CTD相关。
与DM相比，CADM中的ILD更易为急性。CADM与DM在肌炎自身抗体分布及同一肌炎抗体的临床意义方面存在差异，且部分肌炎抗体的临床意义与滴度有关。
