Interpretative Information

This U1RNP assay detects all 3 RNP protein componenets: 70kDa, A, and C. Their presence is typically seen in Mixed Connective Tissue Disease (MCTD), SLE, or Sharp Syndrome. 70kDa (aka RNP70) may be more specific for MCTD and some studies suggest that patients who react with the U1RNP assay, but not the RNP70 assay are more strongly associated with SLE.

A definitive clinical diagnosis should not be based on the results of a single diagnostic method, but should only be made by the physician after all clinical and laboratory findings have been evaluated. This assay has a specificity of 99.9% and a sensitivity of 78.6%.