Determine histamine release in suspected chronic urticaria if urticaria is felt to be due to autoimmune antibodies to the basophil IgE receptor or to IgE.
- 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.
- 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 and freeze immediately. (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: Unacceptable; Refrigerated: Unacceptable; Frozen: 1 year (avoid repeated freeze/thaw cycles)
10 Units or less
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).
|Component Test Code*||Component Chart Name||LOINC|
- CD203c upregulation