Allergen, Weed, Common/Short Ragweed
Also known as: CRAG
Use
This test measures the level of IgE antibodies in the blood specific to the common/short ragweed allergen. It aids in the diagnosis and management of allergic rhinitis and other IgE-mediated allergic disorders. The test quantifies allergen-specific IgE concentrations which, when interpreted in conjunction with a clinical history and in vivo testing, help assess the risk of allergic reactions or the presence of an allergy. Despite showing concentrations reflective of allergen-specific IgE levels, these do not always correlate perfectly with clinical outcomes or skin test results.
Special Instructions
Care must be taken to ensure proper volume and specimen handling. Multiple patient encounters should be avoided prior to sample collection to prevent variations in results. For multiple allergen orders, refer to ARUP's "Allergen Specimen Collection Instructions."
Limitations
Quantitative IgE levels do not directly indicate the severity of an allergy or predict the clinical response; they are an aid in diagnosis. A low IgE level does not rule out allergies or even severe reactions, including anaphylaxis. It is crucial to correlate laboratory results with clinical assessment and history as well as in vivo testing outcomes. The clinical relevance of IgE levels in the range of 0.10-0.34 kU/L is undetermined and should be interpreted by specialists.
FDA ApprovedNew York Approved
Methodology
Immunoassay (Fluorescent Enzyme Immunoassay)
Biomarkers
LOINC Codes
- 6085-5
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
0.25 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Separate serum from cells ASAP or within 2 hours of collection. Transfer to ARUP Standard Transport Tube.
Patient Preparation
Multiple patient encounters should be avoided.
Storage Instructions
Refrigerated.
Causes for Rejection
Hemolyzed, icteric, or lipemic specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 2 weeks |
| Frozen | 1 year |