Anti-U3 RNP Antibodies (Fibrillarin)
Use
The U3-RNP (Fibrillarin) particle participates in the initial step of preribosomal RNA processing. Anti-U3 RNP antibodies are highly specific for patients with systemic sclerosis (SSc), particularly diffuse SSc. These antibodies are associated with isolated pulmonary arterial hypertension, myositis, renal, and cardiac manifestations of the disease. In scleroderma/myositis overlap, the prevalence is about 15%, with a sensitivity of 4-10% for diffuse SSc and below 2% for limited SSc. The antibodies are more prevalent among African-Americans.
Special Instructions
The test is available for clients in New York State. For accurate results, ensure the proper collection and handling of specimens. Detailed collection instructions are provided to maximize test accuracy.
Limitations
This test is not cleared or approved by the FDA as it is developed by LabCorp. The sensitivity for diffuse SSc is low, ranging from 4-10%, and it has limited utility in non-diffuse forms of SSc. Results must be interpreted in the context of clinical findings and other diagnostic procedures due to potential overlap with other autoimmune conditions.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 49963-2
- 49963-2
Result Turnaround Time
16-25 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.3 mL
Container
Plastic vial
Collection Instructions
Draw blood in a plain red-top tube(s); a serum gel tube is acceptable. Spin down and send 1 mL of serum refrigerated in a plastic vial.
Causes for Rejection
Gross hemolysis, gross lipemia, gross icterus, bacterial contamination, and any specimen other than serum will be rejected.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 60 days |