Anti-RNP-70
Anti-RNP-70 is an ELISA-based, automated, in-vitro test system for the quantitative determination of IgG antibodies against RNP-70 in human serum or plasma.
RNP-70, the 70 kDa protein of the U1-snRNP complex, is one of the extractable nuclear antigens (ENA). It is useful for the diagnosis of mixed connective tissue disease (MCTD, Sharp syndrome) and related autoimmune diseases. The diagnostic sensitivity of this marker for MCTD is 100 %; absence of RNP-70 autoantibodies rules out MCTD. Antibodies against RNP-70 are found in up to 32 % of cases of systemic lupus erythematosus (SLE) and up to 10 % of systemic scleroderma cases.