Interleukin-2 Receptor Alpha Chain (IL-2Ra/CD25), Soluble

Interleukin-2 Receptor, Interleukin 2 Receptor by MAFD, CD25, IL2, sCD25, Soluble IL2-Receptor, CD25, IL 2R, Cytokine,  IL2 Receptor

Test Codes

EPIC: LAB1231942, Beaker: IL2AC, Quest: 34298

Department

Send Outs

Instructions

IL-2R levels may demonstrate diurnal variation. Recommend IL-2R levels be determined at the same time of day for improved longitudinal comparison.

No biotin supplements 48 hours prior to blood draw.

Specimen Collection Criteria

Collect: One plain Red-top tube. 

Gold-top SST tube is unacceptable.

• Critical frozen. Send specimens for processing immediately after collection.
• Separate samples must be submitted when multiple tests are ordered.

Physician Office/Draw Specimen Preparation

Critical frozen. Centrifuge to separate serum from cells within two hours of collection. Transfer serum into a plastic transport tube and freeze (-20°C/-4°F or below) immediately.

Preparation for Courier Transport

Transport: 1.0 mL serum, frozen (-20°C/-4°F or below). (Minimum: 0.3 mL)

Rejection Criteria

• Serum separator tube (SST).
• Plasma.
• Received room temperature.
• Received refrigerated.
• Specimens not collected and processed as indicated.

Inpatient Specimen Preparation

Critical frozen. Deliver specimen to the Laboratory immediately for processing.

In-Lab Processing

Critical frozen. Centrifuge to separate serum from cells within two hours of collection. Transfer serum into a plastic transport tube and freeze (-20°C/-4°F or below) immediately.

Transport: 1.0 mL serum, frozen (-20°C/-4°F or below). (Minimum: 0.3 mL) 

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): 24 hours
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.
Results available in 7-9 days.

Reference Range

532-1891 pg/mL.

Test Methodology

Immunoassay (IA)

Clinical Utility

The receptor of the cytokine interleukin 2 (IL-2) plays a crucial role in the regulation of the immune response. Binding of IL-2 to the receptor (IL2R) on the surface of T-lymphocytes triggers a series of intracellular signals that result in activation and proliferation of resting T cells. Research has found sIL2R is present in elevated levels with neoplastic diseases, autoimmune diseases, organ allograft rejection and different infections. It appears the sIL2R is an indicator of a wide spectrum of disorders involving immune activation.

Cytokine levels may demonstrate diurnal variation. For longitudinal comparison, it is recommended that cytokine levels be determined at the same time of day.

CPT Codes

83520

Contacts

Last Updated

11/19/2025