Mixed connective tissue disease (MCTD) is characterized by the presence of anti-U1-snRNP autoantibodies and a variable set of associated clinical features.
A total of 15 peptides were tested in a cohort of 68 patients with SLE, 29 with MCTD and 26 healthy individuals and mapped onto the U1 snRNP structure.
With high titer IgG antibodies to U1 ribonucleoprotein (U1-snRNP), this concept is supported by a specific serologic marker, and autoantibodies to U1-snRNP and to heterogeneous nuclear ribonucleoprotein (hnRNP)-A2 display MCTD specificity with regard to the recognized epitopes.
All components of the U1 snRNP complex, including the U1-70K protein, are important autoantigens in patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD).
Antibodies directed against small nuclear ribonucleoprotein ( snRNP ) particles are found in the Sm and RNP autoimmune sera from numerous patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD).