SCLC, Paraneoplastic Dermatomyositis, Positive Transcription Intermediary Factor 1-γ, and Point Mutation in the Transcription Intermediary Factor 1-γ Coding Gene: A Case Report

Abstract

SCLC is frequently associated with paraneoplastic syndromes, including dermatomyositis. Patients with malignancyassociated dermatomyositis express a specific autoantibody pattern usually positive for anti-transcription intermediary factor 1-g (TIF1-g), suggesting anti-TIF1-g plays a role in development of malignancy-associated dermatomyositis. We present a case of a patient with SCLC, paraneoplastic dermatomyositis, positive anti-TIF1-g, and a point mutation in TIF1-g coding gene, with prominent clinical response to chemoradiation. We suggest that this point mutation is pathogenic, providing evidence for the development of paraneoplastic dermatomyositis through immune cross-reactivity.

Immune checkpoint inhibitor therapy in a patient with small cell lung cancer and anti‐transcriptional intermediary factor 1‐γ antibody‐positive dermatomyositis: A case report

“…Patients with CAD have worse symptoms and a poorer prognosis. 8 They have a distinct autoantibody pattern, with negative DM-specific autoantibody and positive anti-TIF1γ antibody, suggesting that anti-TIF1γ plays a role in the development of CAD. 3,15 The main treatment of DM is corticosteroids, 16 but treatment of malignancy also improves the symptoms of paraneoplastic DM.…”

“…Patients with CAD have worse symptoms and a poorer prognosis. 8 They have a distinct autoantibody pattern, with negative DM‐specific autoantibody and positive anti‐TIF1γ antibody, suggesting that anti–TIF1γ plays a role in the development of CAD. 3 , 15 …”

“…7 TIF1γ acts as a tumor suppressor and regulator of cellular proliferation, through the regulation of the transforming growth factor β (TGF-β) and Smad pathways. 8 Previous studies have confirmed an increased risk of cancer-associated dermatomyositis (CAD) in the presence of anti-TIF1γ autoantibody. [9][10][11][12] Clinicians should screen patients with anti-TIF1γ autoantibody for cancers even in the absence of suspicious symptoms.…”

“…Anti‐transcriptional intermediary factor 1 γ (anti‐TIF1γ) antibody is a promising marker for the assessment of cancer risk in DM patients 7 . TIF1γ acts as a tumor suppressor and regulator of cellular proliferation, through the regulation of the transforming growth factor β (TGF‐β) and Smad pathways 8 . Previous studies have confirmed an increased risk of cancer‐associated dermatomyositis (CAD) in the presence of anti‐TIF1γ autoantibody 9–12 .…”

Comparative analysis of immunotherapy responses in small cell lung cancer patients with dermatomyositis

“…3 Patients with cancer-associated dermatomyositis (CAD) exhibit antitranscription intermediary factor 1-γ (anti-TIF1-γ) antibodies. 4 Mutations or elevated expression of TIF1-γ, a tumor suppressor that regulates the transforming growth factor-beta (TGF-β) signaling pathway, can trigger the production of anti-TIF1γ antibodies, leading to CAD. Although CAD treatment resembles other DM forms, using steroids and immunosuppressants, evidence suggests that CAD often improves alongside cancer treatment.…”