Department of Hematology, Clinical Immunology and Infectious Diseases, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan.
Mod Rheumatol Case Rep. 2022 Jun 24;6(2):194-198. doi: 10.1093/mrcr/rxab054.
Clinically amyopathic dermatomyositis (CADM) patients often develop rapidly progressive interstitial lung disease (RP-ILD). A high level of anti-melanoma differentiation-associated gene 5 antibodies (anti-MDA5 Ab) before treatment is associated with RP-ILD development, a poor treatment response, and poor survival. The prognosis of CADM patients remains poor due to ILD even with combined intensive immunosuppressive therapy. Recently, several additional therapies, including tofacitinib (TOF) and plasma exchange (PE) therapy, have been reported to be effective. We herein report a case of CADM-ILD with a high level of anti-MDA5 Ab that was refractory to combined intensive immunosuppressive therapy including TOF, but successfully treated with PE. The following are possible reasons why TOF was ineffective: (1) cytokines that were not suppressed by TOF played an important role in RP-ILD; (2) TOF was administered later than previously reported; and (3) TOF did not suppress pathological substances such as antibodies. On the other hand, PE removes cytokines and various pathological substances. Therefore, PE may be a more reasonable additional therapy for intractable CADM-ILD.
临床无肌病性皮肌炎（CADM）患者常发生快速进展性间质性肺病（RP-ILD）。治疗前高水平的抗黑色素瘤分化相关基因 5 抗体（抗-MDA5 Ab）与 RP-ILD 发展、治疗反应差和生存不良相关。由于ILD，即使联合强化免疫抑制治疗，CADM 患者的预后仍然很差。最近，已有报道称几种额外的治疗方法，包括托法替尼（TOF）和血浆置换（PE）治疗，对ILD 有效。我们在此报告一例 CADM-ILD 患者，其抗-MDA5 Ab 水平较高，对包括 TOF 在内的联合强化免疫抑制治疗无反应，但成功接受了 PE 治疗。TOF 无效的可能原因如下：（1）TOF 未抑制的细胞因子在 RP-ILD 中发挥重要作用；（2）TOF 的给药时间晚于之前的报道；（3）TOF 未抑制抗体等病理物质。另一方面，PE 可清除细胞因子和各种病理物质。因此，PE 可能是治疗难治性 CADM-ILD 的更合理的附加治疗方法。
