RESUMO
Objective To study the relationship between anti-transcription intermediary factor 1 family proteins (TIF1) autoantibodies profiles and cancer-associated dermatomyositis (CAM) and to define the diagnostic value of different subtypes of anti-TIF1 aotuantibodies for CAM.Methods The sera from 156 patients with dermatomyositis (DM),55 with polymyositis (PM),70 with systemic lupus erythematosus (SLE),60 with rheumatoid arthritis (RA),46 with primary Sj(o)gren syndrome (pSS),14 with systemic sclerosis (SSc),49 with kinds of malignancies and 40 healthy subjects were examined by immunoprecipitation assays followed by western blotting.Statistical analysis were performed using ANOVA,t test Mann-Wittney U and x2 test or Fisher exact test,nonparametric method was used to evaluate the sensitivity and specificity through calculating the area under the receiver operating characteristic curve (ROC).Results In summary,32 of 156 sera from patients with DM (20.5％) were positive for at least one anti-TIF1 autoantibodies.There are four subtypes of anti-TIF1 autoantibodies profiles existed in patients with DM,including 4 patients with only positive anti-TIF1-α (12.5％),20 with only positive anti-TIF1-γ (62.5％),7 with both positive anti-TIF1-α and anti-TIF1-γ (21.9％) and 1 with both positive anti-TIF1-β and anti-TIF1-γ (3.1％).However,only positive anti-TIF1-α (7.3％) was observed in 4 patients with PM.No patients with other CTDs as well as malignancy and healthy subjects were positive for these autoantibodies.The sensitivity and specificity of presence of anti-TIF1-α antibodies for the diagnosis of CAM were 42.9％ and 96.5％,respectively and those of anti-TIF1-β antibodies were 0 and 99.3％,respectively and those of anti-TIF-1-γ antibodies were 64.3％ and 86.6％,respectively.Application of areas of ROC to identify the best performance of test of anti-TIF1 antibodies profiles were 0.70,0.50,0.76,0.74 and 0.71,respectively.Conclusion Joint detection of antiTIF1 autoantibodies profiles can improve the diagnostic capbility for CAM.
