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Giant Ragweed-Specific IgE, Serum — Qualitative

Published: August 9, 2026Updated: August 17, 2026

A blood test that checks for IgE antibodies directed against giant ragweed, helping evaluate possible allergic sensitization.

Quick summary

["A positive result shows sensitization to giant ragweed, but it must be considered alongside symptoms and exposure history."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
15978-0
Short code
Deprecated Giant Ragweed IgE RAST Ql
Synonyms
Deprecated Giant Ragweed IgE RAST Ql
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84484
SNOMED
302774002
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This test measures IgE antibodies directed against giant ragweed pollen. IgE is an immune-system protein associated with allergic reactions.

Why might I need this test?

A clinician may order this test to help evaluate seasonal allergy symptoms such as sneezing, runny nose, itchy eyes, or wheezing after exposure to ragweed.

How is the test performed?

A blood sample is collected, and the serum is tested for giant ragweed-specific IgE antibodies. The result is generally reported as positive or negative.

How do I prepare for the test?

No special preparation is usually required. Tell your clinician about your symptoms, when they occur, and any previous allergy testing or allergy treatment.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A positive result indicates that the immune system has developed IgE antibodies to giant ragweed, which is consistent with sensitization. It does not by itself prove that ragweed is causing your symptoms, so results should be interpreted with your exposure history and clinical examination.

Short name

Giant Ragweed IgE

Frequently asked questions

Does a positive result mean I am allergic to giant ragweed?
It indicates allergic sensitization, but the result must be compared with your symptoms and exposure history. A positive test can occur without clinically important allergy.
Can I have this test without allergy symptoms?
Yes. Allergy-specific IgE testing may be used for various evaluation purposes, including assessing sensitization before immunotherapy.
How does this test differ from a total IgE test?
This test looks for IgE directed specifically against giant ragweed. A total IgE test measures overall IgE in the blood and does not identify the specific allergen.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy