Anti-Sm Ab (RDL)
Also known as: Anti-Extractable Nuclear Antibodies, Anti-Smith Ab
Use
Anti-Sm antibodies offer a highly specific but relatively insensitive clinical marker of SLE. Their overall prevalence ranges from approximately 20-30% in SLE. Anti-Sm reactivity is not described definitively on other diseases, although a few studies describe Sm antibodies in monoclonal gammopathies and uveitis.
Special Instructions
Separate serum from cells within one hour of collection and transfer to a plastic transport tube before shipping. To avoid delays in turnaround time when requesting multiple tests on frozen samples, each test should have a separate frozen specimen.
Limitations
This test may not detect anti-Sm antibodies in all patients with SLE due to its relatively low sensitivity compared to other antibody tests. Also, false positives are possible in rare other conditions, but specificity is generally high for SLE. The test is not definitive and must be interpreted in conjunction with clinical findings and results from other laboratory tests.
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 11090-8
- 11090-8
Result Turnaround Time
14-21 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.3 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
Separate serum from cells within one hour of collection. Transfer to a plastic transport tube before shipping.
Storage Instructions
Refrigerate or freeze.
Causes for Rejection
Grossly hemolyzed; bacterial contamination; lipemic specimen; icteric specimen; non-serum specimen types
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 60 days |
Other tests from different labs that may be relevant