Introduction
Dermatomyositis(DM) is an autoimmune disease with clinical
manifestations of muscle and skin damage, often accompanied by
multisystem involvement, especially in the lungs(Didona et al., 2020).
Positive anti-MDA5 antibodies are highly associated with interstitial
lung disease (ILD), which is a major mortality factor in patients(Bai et
al., 2021). Current conventional drug treatments for DM-ILD include
glucocorticoids, immunosuppressants, and anti-pulmonary fibrosis
drugs(Waldman et al., 2020). Long-term use of glucocorticoids can lead
to many adverse reactions, a high risk of immunosuppressive infections,
unpredictable adverse drug reactions, and the duration of treatment with
anti-pulmonary fibrosis drugs is difficult to manage, resulting in
DM-ILD patients, especially those with positive anti-MDA5 antibodies.
However, the effective treatment rate is low. As a small-molecule
targeted drug, many studies have confirmed the effectiveness of
tofacitinib in the treatment of patients with anti-MDA5-positive
DM-ILD(Chen et al., 2019, Ding et al., 2021). However, there are no
reports of negative conversion of anti-MDA5 antibodies to tofacitinib
treatment. Here, we report a case of anti-MDA5 antibody-positive DM-ILD
in a patient who was treated with hormones and immunosuppressive agents
in combination with tofacitinib and had negative anti-MDA5 antibodies,
which are summarized below for clinical reference.