Ordering Recommendation

Determine whether CD203c is upregulated in suspected chronic urticaria if urticaria may be due to autoimmune antibodies to the basophil IgE receptor or to IgE.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Plain red.

Specimen Preparation

Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature

CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions

Specimens other than serum. Contaminated, grossly hemolyzed, or lipemic specimens.


After separation from cells: Ambient: 30 minutes; Refrigerated: Unacceptable; Frozen: 1 year (avoid repeated freeze/thaw cycles)


Semi-Quantitative Flow Cytometry




7-16 days

Reference Interval

27 percent or less Negative - No basophil activation detected.
28-38 percent Indeterminate - Borderline basophil activation detected.
39 percent or greater Positive - Basophil activation detected.

Interpretive Data

A value of 39 percent or greater suggests the presence of basophil stimulating antibodies (or other serum factors).

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Compliance Category

Laboratory Developed Test (LDT)


1) Chronic urticaria (CU) is a common and complex dermatological condition that is suspected when patients experience persistent hives for over 6 weeks. No published evidence of an exogenous allergen as the cause of this disorder exists. About 45 percent of cases have autoantibodies directed against either basophil or mast cell-associated IgE or the high affinity IgE-Fc receptor (Fc epsilon R1 alpha) (Clin Exp Allergy  2009; 39: 777-87). 

2) The presence of histamine releasing factors (including but not limited to IgE and Fc epsilon R1 alpha-specific autoantibodies) in the patient serum can be indirectly determined by evaluating basophil/mast cell activation status using histamine release assays, autologous serum-skin test, and flow cytometric measurement of the basophil and mast-cell specific marker CD203c.  Serum from CU patients can activate donor basophils, which induces histamine release and CD203c upregulation (J Allergy Clin Immunol 2006; 117: 1430-4).

Hotline History


CPT Codes

88184; 88185 x2


Component Test Code* Component Chart Name LOINC
2005418 Urticaria-Induced Basophil Activation 63369-3
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Anti IgE Receptor Ab
  • Basophil autoantibody test
  • Fc epsilon R1 alpha
  • IgE-Fc receptor 1
Urticaria-Induced Basophil Activation