SMRNP, ENA, Extractable Nuclear Antibodies, RNP
RNP and SmRNP Antibodies
Diagnosis and prognosis of rheumatoid arthritis. A seropositive rheumatoid arthritis generally has a more favorable prognosis than seronegative form. This "rheumatoid factor" is not specific for rheumatoid arthritis; it also appears in serum from patients with Connective Tissue Disease, chronic inflammatory and infectious diseases, pulmonary fibrosis, liver disease and acute viral infections.
See the Mixed Connective Tissue Disease Panel Algorithm for suggested testing strategy.
Separate serum from cells within 2 hours of collection.
Negative ≤ 13 IU/mL
Analytical measuring range is 0.2-8.0 AI (Antibody Index)
Positive result(s) support diagnosis of mixed connective tissue disease, which resembles SLE but is not accompanied by renal involvement.