May be useful in the evaluation of neuropsychiatric SLE, positive predictive value is variable.
Semi-Quantitative Multiplex Bead Assay
This test is New York DOH approved.
- Patient Preparation
- Serum separator tube.
- Specimen Preparation
- Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.2 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Plasma or other body fluids. Contaminated, hemolyzed, or severely lipemic specimens.
- After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
29 AU/mL or less: Negative
30-40 AU/mL: Equivocal
41 AU/mL or greater: Positive
RNP antibody is seen in 95-100 percent of mixed connective tissue disease and is considered specific for this syndrome if other antibodies are negative; RNP is also present in 20-30 percent of systemic lupus erythematosus and 15-25 percent of progressive systemic sclerosis. RNP antigens also contain epitopes that are immunologically identical to free Smith antigens, therefore, the Smith antibody response must be considered when interpreting RNP results..
|Component Test Code*||Component Chart Name|
|0050470||Ribonucleic Protein (U1) (ENA) Ab, IgG|
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
- Anti U1RNP
- Anti-Ribonuclear Protein
- Anti-RNP (ENA) Antibody
- Sm/RNP Antibody
- U1 RNP