Anti-transcription Intermediary Factor-1 Gamma Antibody-positive Dermatomyositis with Interstitial Lung Disease and Multisystem Involvement: A Case Report

ABSTRACT: Dermatomyositis (DM) is a type of inflammatory myopathy of unknown origin that is marked by weakness in the proximal muscles, skin manifestations, and involvement of other systems. The existence of anti-transcription intermediary factor-1 gamma (anti-TIF1 γ) antibodies identifies a specific subgroup linked to cancer, interstitial lung disease (ILD), and unusual clinical presentations. We present a rare and complex case of DM positive for anti-TIF1 γ antibodies, which manifested as inflammatory myopathy, ILD, neuropathy, symptoms of sicca syndrome, and gastrointestinal involvement in an elderly woman with various other health issues. A 69-year-old female patient with progressive weakness in her proximal muscles, joint pain, difficulty swallowing, dry eyes and mouth, a persistent cough, and weight loss. Laboratory tests showed anemia, raised inflammatory markers, a positive antinuclear antibody test, (RF) Rheumatoid Factor, (Anti-CCP) Anti-Cyclic Citrullinated Peptide, and a strongly positive anti-TIF1 γ antibody result. A magnetic resonance imaging of her bilateral thighs indicated signs of inflammatory myositis, while a high-resolution computed tomography (CT) scan of the chest revealed an ILD pattern that was non-(UIP) Usual Interstitial Pneumonia, suggesting the presence of follicular bronchiolitis. Nerve conduction tests indicated sensory-motor axonal neuropathy. A positron emission tomography-CT scan revealed no signs of metabolically active cancer. The patient was diagnosed with anti-TIF1 γ-positive DM featuring ILD and multiple system involvement and began immunosuppressive treatment. This case underscores the diagnostic challenges associated with anti-TIF1 γ DM, particularly in the absence of cancer, and highlights the necessity of a multidisciplinary care approach. Early recognition of antibody-specific manifestations is crucial for proper assessment, outcome prediction, and treatment.