Smith and RNP (U1) (ENA) Antibodies, IgG
3000460
Ordering Recommendation
Useful in confirming a diagnosis of systemic lupus erythematosus (SLE) or mixed connective tissue disease (MCTD) following a positive ANA result. Antibodies may be useful in the differential diagnosis of other systemic autoimmune rheumatic diseases such as systemic sclerosis, Sjögren syndrome, polymyositis, dermatomyositis, and overlap syndromes.
Mnemonic
SMITH_RNP
Methodology
Semi-Quantitative Multiplex Bead Assay
Performed
Sun-Sat
Reported
1-2 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
- Patient Preparation
- Collect
- Serum Separator Tube (SST).
- Specimen Preparation
- Separate 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
- Refrigerated.
- Unacceptable Conditions
- Plasma or other body fluids. Contaminated, hemolyzed, or severely lipemic specimens.
- Remarks
- Stability
- After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Interpretive Data
Refer to report.
Note
Hotline History
View Hotline History
CPT Code(s)
Components
| Component Test Code* | Component Chart Name | LOINC |
|---|---|---|
| 0050085 | Smith (ENA) Antibody, IgG | 18323-6 |
| 0050470 | Ribonucleic Protein (U1) (ENA) Ab, IgG | 33983-8 |
Aliases
- Anti U1RNP
- Anti-Ribonucleic Protein
- Anti-RNP (ENA) Antibody
- Anti-Sm
- Anti-Smith (ENA) Antibody
- Sm antibody IgG
- Sm/RNP
- Sm/RNP Antibody
- U1 RNP