Urticaria-Inducing Activity

Casandra

Casandra Test Code AR68705Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 2005413CPT Code 86352

Urticaria-Inducing Activity

Also known as: UIA

Clinical Use

Order Test

Use

This test helps determine the presence of autoantibodies that stimulate basophils in patients with suspected chronic urticaria. Chronic urticaria (CU) is a complex dermatological condition characterized by persistent hives lasting more than six weeks. In approximately 45% of cases, CU is associated with autoantibodies against basophil or mast cell-associated IgE or the high-affinity IgE-Fc receptor. Detection of histamine-releasing factors provides insight into the autoimmune nature of the condition, potentially guiding treatment approaches.

Special Instructions

Not provided.

Limitations

The Urticaria-Inducing Activity test has not been cleared or approved by the US Food and Drug Administration and was developed as a Laboratory Developed Test (LDT) at ARUP Laboratories. Hence, while it adheres to CLIA guidelines and is intended for clinical use, its limitations include potential variability in histamine release assays and inherent challenges in standardizing basophil/mast cell activation measurements. It may not identify all cases of autoimmune urticaria due to the complex and varied nature of antibody interactions involved.

Test Details

New York Approved

Methodology

Immunoassay (ELISA)

Biomarkers

Histamine-releasing antibodies

Analyte

Histamine release measurement

Concentration / Level • Categorical (e.g., Positive / Negative / Indeterminate)

LOINC Codes

Result Codes

63369-3 - Chronic urticaria index Ser-aCnc

Result Turnaround Time

11-14 days

Specimen

Serum

Volume

1 mL

Minimum Volume

0.5 mL

Container

ARUP Standard Transport Tube

Collection Instructions

Separate serum from cells ASAP or within 2 hours of collection. Freeze immediately.

Patient Preparation

Patients taking calcineurin inhibitors should stop their medication for 72 hours prior to draw. Patients on prednisone should be off medication for 2 weeks prior to draw.