DISCUSSION
Anti-MAD5 antibody-positive DM has a rapid onset, more severe disease, and worse prognosis. ILD is the leading cause of death in patients with anti-MDA5 antibody-positive DM patients(Motegi et al., 2019, Yamaoka et al., 2014). DM is a rare disease, and many drugs have been recommended for its treatment, including glucocorticoids, methotrexate, tacrolimus, cyclosporine, and intravenous immunoglobulin, which have been proven to be clinically effective(Lundberg et al., 2017). However, when the abovementioned adverse reactions occur or are ineffective, there are few drugs to choose from. Tofacitinib has been shown to have good efficacy in patients with DM patients(Paik et al., 2021, Kurasawa et al., 2018). On this basis, we selected tofacitinib with the full informed consent of the patients and achieved a good curative effect.
Reviewing this patient, although serum muscle enzymes were not elevated throughout, our diagnosis was considered despite the consistent absence of elevated serum myosin and the presence of fatigue, neck rash, electromyography suggestive of myogenic lesions, muscle biopsy suggesting inflammatory myopathy, changes in ILD, and positive myositis antibody and anti-MDA5 antibody. Anti-MDA5 antibody was positive for DM. Initially, the patient responded well to treatment, but as the steroids were tapered, the patient’s symptoms and imaging findings did not resolve significantly. The patient did not experience significant relief even with the addition of cyclophosphamide and tacrolimus. However, we attempted tofacitinib because of the prolonged use of tacrolimus and the negative effects of steroid hormones, and we were able to successfully reduce and cease using steroid hormones after 16 weeks of tofacitinib treatment. The anti-MDA5 antibody test was effectively negative after 96 weeks, but the patient’s symptoms persisted. The remission, lung CT, and ILD manifestations were successfully reversed. Therefore, we believe that it plays a potential role in the maintenance therapy of anti-MDA5 antibody-positive DM-ILD.
In conclusion, we report a patient with anti-MDA5 antibody-positive DM-ILD and conclude for the first time that tofacitinib may be an option for anti-MDA5 antibody-positive conversion during maintenance therapy. However, further clinical and experimental studies are needed to confirm this hypothesis.