Recommended for the diagnosis of systemic sclerosis in patients negative for centromere, Scl-70, or RNA polymerase III antibodies. May predict skeletal muscle involvement and pulmonary arterial hypertension.
- Patient Preparation
- Serum separator tube.
- Specimen Preparation
- Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.5 mL)
- Storage/Transport Temperature
- Refrigerated. Also acceptable: Frozen.
- Unacceptable Conditions
- Grossly hemolyzed or severely lipemic.
- After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year
In a multi-ethnic cohort of SSc patients (n=98), U3-RNP antibodies detected by immunoblot had an agreement of 98.9 percent with the gold standard immunoprecipitation (IP) assay. Approximately 71 percent (5/7) of the borderline U3-RNP results with ANA nucleolar pattern in this cohort were IP negative.
|Component Test Code*||Component Chart Name||LOINC|
|2012174||Fibrillarin (U3 RNP) Ab, IgG||49963-2|