Histamine Release (Chronic Urticaria)

CU Index, Anti-FceR™, CD203, FC Epsilon Receptor Antibody, Anti-IgE Receptor, Chronic Urticaria, CU (Chronic Urticaria), FCER1, Chronic Urticaria

Test Codes

EPIC: LAB1231935, Beaker: CU Index, Quest: 16838

Department

Send Outs

Instructions

Patients taking calcineurin inhibitors should stop their medications 72 hours prior to draw.

Specimen Collection Criteria

Collect: One plain Red-top tube (no gel).

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: 1.5 mL serum, room temperature (20-26°C or 68-78.8°F). (Minimum: 1.0 mL)

Rejection Criteria

• Gross hemolysis.
• Grossly lipemic.
• Icteric.
• Serum separator tube.
• Specimens not collected and processed as indicated.

Inpatient Specimen Preparation

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. (Minimum: 1.0 mL)

Transport: 1.5 mL serum, room temperature (20-26°C or 68-78.8°F). (Minimum: 1.0 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): 7 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

Tuesday, Thursday.
Results available in 4-9 days.

Reference Range

<16 %

Test Methodology

Cell Culture (CC), Immunoassay (IA)

Clinical Utility

Histamine Release (Chronic Urticaria) - Chronic Urticaria (CU) is a common skin disorder affecting 1 to 6% of the general population. It is characterized by repeated occurrences of short-lived cutaneous wheals accompanied by redness and itching. Autoimmune urticaria is defined by the presence of a functional IgG antibody to high-affinity IgE receptor (Fc epsilon RI alpha) or IgE. These antibodies trigger mast cell and basophil degranulation by the engagement of Fc epsilon receptor. Functional IgG antibody to the receptor has been identified in approximately 30-40% of patients with CU, and anti-IgE antibody has been identified in another 5%-10%.

CPT Codes

86343

Contacts

Last Updated

11/19/2025