Clinical profile of anti-transcription intermediary factor-1 gamma-positive adults from a single tertiary care center

Anti-transcription intermediary factor-1 γ (TIF-1 γ) antibody is a myositis-specific antibody. These cases had specific clinical features in the past studies. There is no published data on such patients from South Asia. We retrospectively looked at data from patients with positive anti-TIF-1 γ antibodies from our hospital database between May 2019 and October 2020. Their clinical presentation, muscle and extra muscular involvement, investigations, presence of malignancy, and treatment with subsequent follow-up were retrieved using the electronic medical records. TIF-1 γ was rare at our center and was 2.46% out of the total positive myositis immunoblot results. Seven adult patients had significant anti-TIF-1 γ positivity. Five out of them had clinical muscle weakness; none had severe or respiratory muscle weakness. No patients had cancer-associated myositis. The skin was the most common extra muscular organ involved. The absence of cancer-associated myositis with anti-TIF-1 γ subjects in our series may represent the difference in phenotype in the South Asian population.