Clinical significance of anti-transcriptional intermediary factor 1-γ antibody in patients with dermatomyositis: a monocentric cross-sectional study

Objectives: To determine the prevalence of anti-transcriptional intermediary factor 1-γ antibody (anti-TIF1-γ-Ab) and to explore its associations with clinical features in patients with dermatomyositis.

Methods: Sixteen kinds of myositis-specific/associated antibodies were examined in 141 dermatomyositis patients by western blotting. Clinical features and laboratory data were collected. The frequency of anti-TIF1-γ-Ab positivity and its correlations with clinical phenotypes were analyzed using SPSS 23.0 software.

Results: Dermatomyositis patients with anti-TIF1-γ-Ab were prone to malignancy (P < 0.001); were more likely to present with heliotrope rash (P = 0.007), shawl sign (P < 0.001), and V sign (P < 0.001); and had relatively longer disease duration (P = 0.031), but were less likely to present with interstitial lung disease (P < 0.001) and mechanic's hand (P = 0.003) than the anti-TIF1-γ-Ab-negative subgroup. Anti-TIF1-γ-Ab status was independently associated with the presence of malignancy during multivariate logistic regression analysis. Among the anti-TIF1-γ-Ab-positive dermatomyositis patients, the subgroup with malignancy was prone to present with all types of rashes (87.5% vs. 13.3%, P = 0.001) and has higher incidence of male than the without-malignancy subgroup (50% vs. 6.7%, P = 0.033).

Conclusions: Anti-TIF1-γ-Ab positivity was identified as a specific serological indicator of dermatomyositis with malignancy. Men with anti-TIF1-γ-Ab positivity were more likely to have malignancy than women. Increasing types of rashes were associated with greater likelihood of developing malignancy. Key Points • The clinical features of anti-TIF1-γ-Ab in patients with dermatomyositis.