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HelpTest Code Billings Clinic: 9127 Mayo: RNAP RNA Polymerase III Antibodies, IgG, Serum
Reporting Name
RNA Polymerase III Ab, IgG, SPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
Evaluating patients suspected of having systemic sclerosis as part of systemic sclerosis criteria antibody tests
Providing diagnostic and prognostic information in patients with systemic sclerosis
Method Name
Enzyme-Linked Immunosorbent Assay (ELISA)
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.3 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Type
SerumSpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 21 days | |
| Frozen | 21 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | OK |
| Heat-treated specimen | Reject |
Reference Values
<20.0 U (negative)
20.0-39.9 U (weak positive)
40.0-80.0 U (moderate positive)
>80.0 U (strong positive)
Interpretation
A positive result for RNA polymerase III antibody may support a diagnosis of systemic sclerosis (SSc) in the appropriate clinical context. Anti-RNA polymerase III autoantibody in patients with SSc is associated with the diffuse cutaneous form of disease and an increased risk of sclerodermal renal crisis.
A negative result indicates no detectable IgG antibodies to RNA polymerase III and does not rule out a diagnosis of SSc. The RNA polymerase III IgG enzyme-linked immunosorbent assay tests only for the RP155 dominant epitope, other epitopes in the antigenic complex are absent and cannot be detected.(6) The overall pooled prevalence of anti-RNA polymerase III antibody is reported to be 11%, 95% CI: 8 to 14, range of 0% to 41% in published studies.(4)
Day(s) Performed
Tuesday, Thursday
Report Available
2 to 7 daysTest Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
83516
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| RNAP | RNA Polymerase III Ab, IgG, S | 79182-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| RNAP | RNA Polymerase III Ab, IgG, S | 79182-2 |