Anti-RNP/Sm is an ELISA-based, automated, in-vitro test system for the quantitative determination of IgG antibodies against the RNP/Sm ribonucleoprotein complex in human serum or plasma.

The RNP/Sm complex is an extractable nuclear antigen (ENA) and is useful in the diagnosis of mixed connective tissue disorder (MCTD, Sharp syndrome) and related autoimmune diseases. The antigen is a multi-enzyme complex made of three U1-specific ribonucleoproteins (U1-A, U1-C, U1-70 kDa) and nine different Sm core proteins. Antibodies against the 70 kDa protein of this complex are a very specific marker for Sharp syndrome. Nearly all affected patients have autoantibodies against this target antigen; absence of RNP/Sm antibodies thus rules out this disease. The Sm proteins and the ribonuncleoproteins A and C are recognized by antibodies that also occur in cases of mixed connective tissue disorder and systemic lupus erythematosus. However, SLE patients generally have lower titres of antibodies against the 70 kDa protein than MCTD patients.


Product Number ORG 211
Tests24 Alegria® strips
Range0 - 200 U/ml
Cut-off25 U/ml
Coating RNP/Sm complex

ORG 200   ORG 206   ORG 238  


ORG 506   ORG 511   ORG 514   ORG 538   ORG 539   ORG 544   ORG 546   ORG 600  


ORG 710   ORG 711  


Instruction for Use
Safety Data Sheet

Document Archive
Instruction for Use Revision 4. Earlier versions and additional languages can be found in the document archive.