Anti-TIF1γ-positive dermatomyositis with interstitial lung involvement: report of two cases

Introduction: The association of certain myositis-specific antibodies (MSA) with the development of interstitial lung disease (ILD) in relation to inflammatory myopathies, such as antisynthetase syndrome and anti-MDA5, is well known. However, the potential relationship with the anti-TIF1γ antibody is not well understood, as the reported cases to date are few and have not allowed for solid confirmation of this association. Most of the literature has focused primarily on the association with malignant neoplasms. We aim to include two new cases in the existing literature to support the assertion of the link despite its infrequency. Objective: To report two cases of ILD associated with anti-TIF1γ positive dermatomyositis (DM). Materials and methods: A description of the clinical characteristics of two cases of anti-TIF1γ positive DM with ILD and a comparison with analogous cases. Results: Two cases are described, the first of a 47-year-old man and the second of a 57-year-old woman, both diagnosed with anti-TIF1γ positive DM with the presence of ILD. Underlying malignancy was ruled out due to the presence of the MSA in question, and other potential causes of ILD were excluded, leading to the initiation of immunosuppressive treatment in both cases. Conclusion: It is essential to further investigate the relationship between inflammatory myopathy and how different MSAs, other than antisynthetase and anti-MDA5 are also associated with ILD. Finding two cases related to anti-TIF1γ and knowing that there are analogous cases generates this hypothesis.