Total Serum Casein IgE Levels (or Total Immunoglobulin E in Serum)
This test measures the total amount of Immunoglobulin E (IgE), a protein in your blood linked to allergic reactions.
["IgE levels help identify allergies or immune responses to certain triggers."]
Key facts at a glance
- LOINC
- 61241-6
- Short code
- CASIGE
- Synonyms
- Casein IgE/IgE total %
- Category
- chemistry
- Sample
- serum
- Container
- Red-top serum separator tube (SST) or plain red-top tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 0.35
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunoassay (Fluorescent Enzyme Immunoassay or Chemiluminescent Immunoassay)
- CPT
- 86003
- SNOMED
- 395141000119100
- Specimen volume
- 1 mL serum (minimum 0.5 mL)
- Stability
- Stable for 7 days at 2-8°C; stable for 1 month at -20°C; avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
What Does This Test Measure?
IgE is a type of antibody produced by your immune system in response to allergens (substances like pollen, dust, or foods). High levels may suggest allergies, asthma, or other allergic conditions. This test does not specify which allergen is causing the reaction.
Why Might You Need This Test?
Your doctor may order this test if you have symptoms like sneezing, itching, skin rashes, or breathing difficulties that suggest allergies. It can also help diagnose conditions like allergic rhinitis, eczema, or certain types of asthma.
How Is the Test Performed?
A blood sample is taken from a vein in your arm. The blood is sent to a lab where it is processed to measure total IgE levels using an immunoassay method. Results are typically available within a few days.
What Are Common Results and Next Steps?
Results may be reported as a range or a single value. High IgE levels might indicate allergies or immune-related conditions, while normal levels do not rule out allergies entirely. Your doctor will discuss results and next steps, such as allergy testing or treatment options.
Reference range
Class 0: <0.35 kU/L (Negative); Class 1: 0.35-0.69 kU/L (Low); Class 2: 0.70-3.49 kU/L (Moderate); Class 3: 3.50-17.49 kU/L (High); Class 4: 17.50-49.99 kU/L (Very High); Class 5: 50.00-99.99 kU/L (Very High); Class 6: >=100 kU/L (Very High). Total IgE reference range: 0-100 IU/mL for adults.N/A
No special preparation required. Patient should inform provider of all medications, especially antihistamines, though these do not typically interfere with IgE antibody testing.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
Total IgE (Serum)
Frequently asked questions
How often will I need this test?
Can I do anything to prepare for this test?
What does a high or low IgE level mean?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 16, 2026. · Read our editorial policy