Quick Facts
- Sample: Blood
- Fasting: No special preparation is required
- Turnaround: 3-5 business days. May take longer based on weather, holiday, or lab delays.
What This Test Measures
This test measures clam-specific IgE antibody levels in a blood sample, using the biomarker F207-IgE Clam. IgE antibodies are produced by your immune system in response to specific proteins it identifies as a threat, and elevated levels can indicate sensitization to clam.
This test evaluates clam only. It does not measure IgE levels for other shellfish, such as shrimp, crab, lobster, or oysters, and it does not test for IgG antibodies or any other food allergen. A result from this test reflects sensitization to clam specifically and is not, by itself, a diagnosis of clinical food allergy.
Benefits
- Measures IgE antibody levels specific to clam
- Requires only a standard blood draw
- No special preparation or fasting needed
- Results typically available in 3 to 5 days
- Provides objective lab data to discuss with your healthcare provider
Who Is This Test For?
- Individuals who have experienced symptoms after eating clams
- People wanting to check sensitization to clam specifically, rather than shellfish broadly
- Those working with a healthcare provider to evaluate a suspected reaction linked to clam consumption
- Individuals who eat clams regularly and want lab data to discuss with a provider
- People whose healthcare provider has recommended IgE testing for clam as part of an evaluation
How It Works
- Order Your Test Online
- Visit a Local Lab
- Get Results Online
FAQ
1. What does this test measure, and how is it different from other shellfish allergy tests?
This test measures IgE antibodies specific to clams, using the F207 biomarker, from a blood sample. Shellfish allergy is most commonly associated with crustaceans like shrimp, crab, lobster, prawns, and crawfish, and allergy to clams specifically is less common. This test does not measure IgE to those other shellfish or to any other food allergen, so it is intended to check clam sensitization on its own rather than shellfish allergy as a whole.
2. Who should consider this test, and when?
People who have noticed symptoms after eating clams, or who eat clams regularly and want lab-based information, are the primary audience for this test. It may also be considered as part of a broader evaluation guided by a healthcare provider when a reaction to clams specifically is suspected.
3. Do I need to fast or prepare for this test?
No special preparation is required for this test. You can have your blood drawn without fasting or adjusting your diet beforehand.
4. How quickly will I get my results?
Results are typically available in 3 to 5 days. Turnaround may take longer due to weather, holidays, or other lab delays.
5. How should I interpret my results, and what should I do if they are abnormal?
An elevated IgE result indicates sensitization to clams, but interpretation depends on your symptoms, exposure history, and other clinical information, so it does not confirm a clinical food allergy on its own. A result within the expected range does not guarantee that clams can be consumed without risk. If your result is abnormal, or if you have concerns about your results, review them with a qualified healthcare provider who can consider them alongside your medical history.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
No special preparation is required.
Cross Reactivity
Cross-reactivity can occur when your immune system recognizes similar proteins across different allergen sources, sometimes leading to a reaction to a substance you were not originally sensitized to. This test measures only clam-specific IgE antibodies and does not test for the additional foods, pollens, or substances described below. The relationships below are examples, not a complete list, and they represent possible additional considerations rather than confirmed allergies. Cross-reactivity does not mean you will necessarily react to another listed substance, and related allergen testing may be worth discussing with your healthcare provider depending on your history and symptoms.
- Other mollusks (oyster, mussel, scallop, squid, octopus, abalone, snail): Cross-reactivity within mollusks has been reported, largely tied to a shared muscle protein called tropomyosin, though clinical reaction patterns vary by individual.
- Crustacean shellfish (shrimp, crab, lobster, prawns, crawfish): Some cross-reactivity between mollusks and crustaceans has been described, though this relationship is less clearly defined than cross-reactivity among mollusks alone, and many people who react to one group can tolerate the other.
- House dust mite and cockroach: Tropomyosin found in shellfish shares structural similarity with tropomyosin in dust mites and cockroaches, which has been associated with cross-reactive IgE in some individuals with perennial allergies.
These relationships are complex and vary from person to person. A healthcare provider can help determine whether additional evaluation of related allergens may be relevant based on your symptoms and history.
