RNA Polymerase III Antibody [19899X]

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Test Code

Alias/See Also

CPT Codes

Preferred Specimen
1 mL serum

Minimum Volume
0.5 mL

Transport Temperature
Room temperature

Specimen Stability
Room temperature: 7 days
Refrigerated: 30 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Grossly lipemic

Enzyme Linked Immunosorbent Immunoassay (ELISA)

Setup Schedule
Set up: Wed, Sat; Report available: 3-6 days

Reference Range
<20 Units

Clinical Significance
Autoantibodies to RNA Polymerase III antigen are found in 11% to 23% of patients with systemic sclerosis. Patients who are positive for RNA Polymerase III antibodies do not have any of the other antibodies typically found in systemic sclerosis patients such as anti-centromere, anti-Scl-70, or anti-Pm/Scl antibodies. Thus, they are a separate serologic group. Numerous studies have shown that these patients have an increased risk of the diffuse cutaneous form of scleroderma, with high likelihood of skin involvement and hypertensive renal disease.

Antibodies to several different types of RNA Polymerases are found in patients with systemic sclerosis. The immunodominant epitope or RNA Pol III was identified and cloned. The recombinant immunodominant epitope of RNA Pol III can be used in ELISA with high specificity to detect anti-RNA Pol III antibodies in patients with the diffuse cutaneous form of systemic sclerosis, with a high incidence of skin involvement.

Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042

Last Updated: December 6, 2021

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.