학술논문

ELISA, protein immunoprecipitation and line blot assays for anti-TIF1-gamma autoantibody detection in cancer-associated dermatomyositis.
Document Type
Article
Source
Rheumatology. Dec2022, Vol. 61 Issue 12, p4991-4996. 6p.
Subject
*TUMOR risk factors
*TUMOR diagnosis
*AUTOANTIBODIES
*NUCLEOTIDE separation
*REPORTING of diseases
*DERMATOMYOSITIS
*PREDICTIVE tests
*PRECIPITIN tests
*IMMUNOBLOTTING
*RISK assessment
*COMPARATIVE studies
*ENZYME-linked immunosorbent assay
*DESCRIPTIVE statistics
*SENSITIVITY & specificity (Statistics)
*DISEASE complications
Language
ISSN
1462-0324
Abstract
Objectives Anti‐TIF1-gamma autoantibodies can be detected with immunoprecipitation (IP), line blot (LB) and ELISA. We compared assay performance in patients with DM and the potential of these assays to detect anti-TIF1-gamma positive cancer-associated DM (CADM). Methods We included sera from 131 patients with DM followed at Karolinska University Hospital, Stockholm, Sweden and 82 healthy controls. Serum samples taken at DM diagnosis were tested for anti-TIF1-gamma autoantibodies with IP, two ELISAs (in-house and commercial) and LB. Cancer diagnosis and dates were obtained from the Swedish national cancer register. CADM was defined as a malignancy that developed within 3 years of DM diagnosis. Results Anti-TIF1-gamma autoantibodies were detected in 19/101 (18.8%), 15/113 (13.2%), 34/131 (26%) and 45/131 (34.4%) of the patients with IP, LB, in-house and commercial ELISA, respectively. The anti-TIF1-gamma results from the in-house ELISA were confirmed with IP in 93 of 101 (92%) cases, κ = 0.76, with a commercial ELISA in 110 of 131 (84%) cases, κ = 0.63, and with LB in 101 of 113 (89.3%) cases, κ = 0.67. Anti-TIF1-gamma results with IP were confirmed with LB in 85 of 92 (92.4%) cases, κ = 0.73. For detecting CADM, the anti-TIF1-gamma in-house ELISA had a sensitivity of 58% and specificity of 86%, the commercial ELISA had a sensitivity of 63% and specificity of 82%, IP had a sensitivity of 52% and specificity of 92%, LB had a sensitivity of 40% and specificity of 96%. Conclusion The two anti-TIF1-gamma ELISA assays had advantages both for autoantibody detection and to identify anti-TIF1-gamma-positive CADM. [ABSTRACT FROM AUTHOR]