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.


Semi-Quantitative Flow Cytometry


Mon, Fri


7-10 days

New York DOH Approval Status
This test is New York DOH 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)

Reference Interval

27 percent or less

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).

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