Abstract
Anti-Sm antibodies and anti-RNP antibodies are considered to be diagnostic markers of systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). However, cross-reactivity between the antibodies diminishes their discriminating specificity between these diagnoses. We examined whether we could achieve better differentiation between these two disease entities using recombinant antigens to RNP70 and SmD and quantitative immunoassays. Sera from 51 patients with SLE and 10 patients with MCTD and from a control group of 59 patients were used in a cross-sectional setting. Semiquantitative ELISAs for the detection of antibodies to RNP-70, RNP-A, RNP-C, SmBB' and SmD were used and the results were compared to conventional ELISA tests using U(1)-snRNP and a mixture of SmBB' and SmD as antigenic substrates. Sera from MCTD patients showed higher levels of anti-RNP-70 antibodies than sera from SLE patients. Levels of anti-SmBB' or anti-SmD antibodies were not significantly different between SLE and MCTD sera. However, the presence of antibodies directed against SmD was more frequent in SLE. Our results suggest that the use of RNP-70 and SmD antigens may increase the practical value of immunoassays used to confirm a diagnosis of SLE or MCTD in patients with connective tissue disease.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the European Academy of Dermatology and Venereology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
