Alpha-Gal IgE Panel

Casandra

Casandra Test Code LC64751Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 650003CPT Codes 82785, 86003, 86008

Clinical Use

Use

Measurement of IgE to galactose alpha-1,3-galactose (α-Gal sIgE) is used in the differential diagnosis of α-Gal mediated allergy.1,2 There are two distinct forms of this allergy: the first is an immediate-onset anaphylaxis observed following intravenous infusion of Cetuximab, a monoclonal antibody against epidermal growth factor receptor, and the second is a delayed-onset allergy or anaphylaxis that occurs several hours following consumption of red meat.3 Bites from certain ticks, such as the Lone Star Tick in the United States, have been implicated in the development α-Gal allergy. Furthermore, α-Gal may be helpful in elucidating the allergen responsible in patients initially diagnosed as having ‘idiopathic’ anaphylaxis or urticaria.4-6

Special Instructions

Total IgE levels are valuable in assessing potential α-Gal allergy because some cases are non-atopic with low total IgE. The test also includes measurements of Immunoglobulin E, Total; Alpha-Gal; Beef IgE; Pork IgE; Lamb IgE.

Limitations

Component IgE testing enhances evaluation over the use of whole extracts alone but cannot replace clinical history and oral food challenge in most cases. Clinical history, age, and comorbidities must be considered. Detected IgE to α-Gal may not always correlate with allergic symptoms. Many produce IgE to α-Gal without symptoms. If a food is tolerated regularly, detectable IgE does not confirm allergy. Undetectable specific IgE does not exclude allergy if clinical history suggests otherwise.

Test Details