Notes

Antibody results should not be used alone for diagnosis and must be interpreted in light of clinical manifestations and other test results.
RNP70 antibodies typically appear in both SLE and mixed connective tissue disease (MCTD, Sharp Syndrome). In MCTD, the presence of U1RNP antibodies is required for diagnosis, whereas they occur in only 30 to 40% of SLE patients. RNP70 antibodies may be more specific for MCTD, as they have been reported to occur less frequently in SLE.