Anti-TIF-1 gamma Antibody Detection Using a Commercial Kit vs In-House Immunoblot: Usefulness in Clinical Practice
Objectives Anti-TIF-1 gamma autoantibody detection is important for cancer screening in patients with dermatomyositis. The gold standard for anti-TIF-1 gamma detection, immunoprecipitation, is only available from a few specialized laboratories worldwide, so commercial ELISA/immunoblot tests have eme...
| Authors: | ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; |
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| Format: | Article |
| Status: | Published version |
| Publication date: | 2021 |
| Country: | España |
| Institution: | Institut d’Investigació Biomèdica Sant Pau (IIB Sant Pau) |
| Repository: | r-IIB SANT PAU. Repositorio Institucional de Producción Científica del Instituto de Investigación Biomédica Sant Pau |
| OAI Identifier: | oai:iibsantpau.fundanetsuite.com:p5046 |
| Online Access: | https://iibsantpau.fundanetsuite.com/Publicaciones/ProdCientif/PublicacionFrw.aspx?id=5046 |
| Access Level: | Open access |
| Keyword: | dermatomyositis cancer autoantibody diagnosis immunoassay |
| Summary: | Objectives Anti-TIF-1 gamma autoantibody detection is important for cancer screening in patients with dermatomyositis. The gold standard for anti-TIF-1 gamma detection, immunoprecipitation, is only available from a few specialized laboratories worldwide, so commercial ELISA/immunoblot tests have emerged in recent years. To analyze their usefulness in diagnosing cancer-associated dermatomyositis, we compared Euroimmun Euroline profile with our previously validated in-house immunoblot assay with human recombinant TIF-1 gamma. Methods We included 308 adult patients from Hospital de la Santa Creu I Sant Pau and Vall Hebron Hospital (Barcelona, Spain) tested for anti-TIF-1 gamma autoantibodies using the Euroline profile and an in-house immunoblot assay. Results A total of 27 anti-TIF-1 gamma were detected by the Euroline and 12 by the in-house assay. Fair agreement was observed between Euroline and the in-house immunoblot Cohen's kappa 0.3163. Expected prevalence of anti-TIF-1 gamma autoantibodies was observed for the two methods for dermatomyositis and undifferentiated connective tissue diseases, but unexpectedly high prevalence of anti-TIF-1 gamma autoantibodies was detected by Euroline compared to the in-house immunoblot for other diseases (16.5% Euroline vs 0.8% in-house immunoblot, p<0.01). The in-house IB compared to Euroline more reliably detected cancer in patients with DM with anti-TIF-1 gamma antibodies (p=0.0014 vs p=0.0502 for in-house immunoblot vs Euroline). Conclusion We recommend using a second validated method to confirm Euroline-detected anti-TIF-1 gamma antibodies when the dermatomyositis diagnosis is not definitive. Furthermore, in the context of definite DM diagnosis with negative anti-TIF-1 gamma antibodies by Euroline and no other myositis specific antibody, is also recommendable to confirm by a second validated method. |
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