RNA Polymerase III Antibody

pol 3, Anti-RNAP III

Test Codes

EPIC: LAB1232068, Beaker: RNA Polymera, Quest: 19899

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top Serum Separator Tube (SST).

Also Acceptable: One plain Red-top tube.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to plastic transport tube and maintain at room temperature (20-26°C or 68-78.8°F) prior to transport.

Preparation for Courier Transport

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46) prior to transport. (Minimum: 0.5 mL)

Rejection Criteria

• Gross hemolysis.
• Grossly lipemic.
• Received at room temperature.
• Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to plastic transport tube and maintain at room temperature (20-26°C or 68-78.8°F) prior to transport.

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46). (Minimum: 0.5 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 7 days
Refrigerated (2-8°C or 36-46°F): 30 days
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Wednesday – Saturday.
Results available in 4-7 days.

Reference Range

<20 Units

Test Methodology

Enzyme Linked Immunosorbent Immunoassay (ELISA)

Clinical Utility

RNA Polymerase III Antibody – 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.

CPT Codes

83516

Contacts

Last Updated

3/4/2026