Anti-TIF1 gamma antibodies (anti-p155) in adult patients with dermatomyositis: comparison of different diagnostic assays

作者：Labrador Horrillo Moises^*; Angeles Martinez Maria; Selva O' Callaghan Albert; Trallero Araguas Ernesto; Balada Eva; Vilardell Tarres Miquel; Juarez Candido

来源：Annals of the Rheumatic Diseases, 2012, 71(6): 993-996.

DOI：10.1136/annrheumdis-2011-200871

Background A new myositis-specific autoantibody (anti-p155) directed against transcriptional intermediary factor 1 gamma (TIF1 gamma) has been described as a good marker of cancer-associated myositis (CAM). %26lt;br%26gt;Objective To analyse the feasibility of detecting this autoantibody in patient serum samples using new assays with commercially available recombinant TIF1 gamma. %26lt;br%26gt;Methods The study included 90 Spanish patients with dermatomyositis (DM), classified as clinically amyopathic DM, CAM, or DM without cancer. Anti-TIF1 gamma antibodies were detected by ELISA and immunoblot techniques and compared with anti-p155 antibody detection by protein immunoprecipitation assays with radiolabelled HeLa cells. The kappa coefficient was used to compare the agreement between the different tests. %26lt;br%26gt;Results Serum samples from 23 (25.6%) and 20 (22.2%) patients with DM recognised TIF1 gamma by ELISA and immunoblot, respectively. ELISA (kappa=0.91) and immunoblot (kappa=0.88) showed excellent agreement with immunoprecipitation analysis (anti-p155). Good concordance (kappa=0.91) was also seen between ELISA and immunoblot. %26lt;br%26gt;Conclusions Excellent agreement was found between anti-p155 detected by immunoprecipitation and anti-TIF1 gamma detected by ELISA or immunoblot. These data indicate that identification of this autoantibody can be reliably performed in a standard laboratory setting, with potential application in clinical practice for cancer screening in adult patients with DM.

• 出版日期2012-6