Clinical usefulness of antibodies to U1snRNP proteins in mixed connective tissue disease and systemic lupus erythematosus.

Abstract

IgGs to 68 kDa U1snRNP are not associated with a specific pattern of anti-RNP-positive connective tissue disease. No useful information can be gained by monitoring anti-68 kDa U1snRNP IgG titers over time. A Western blot profile including anti-A U1snRNP or anti-C U1snRNP indicates a high likelihood of U1snRNP-associated mixed connective tissue syndrome (MCTD).