Do Patients With Fish or Shellfish Allergy Tolerate the Consumption of Fish Oil Supplements? A Clinical Study

Study Overview
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Brief Summary
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The purpose of this clinical study is to test whether patients with fish or shellfish allergy can ingest different types of fish oil supplements without having an allergic reaction. To achieve this, the recruited participants will be asked to: provide a blood sample (used for Basophil Histamine Release Assay) undergo a skin-prick-test partake in multiple oral provocations These three tests will indicate the likelihood that the participants can consume fish oil supplements without adverse allergic reactions (See the detailed description for an explanation of the tests). The investigators will test the participants tolerance for three different types fish oil supplements: Fish oil, Cod liver oil, and krill oil.

Detailed Description
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The Basophil Histamine Release Assay is a test that indicates whether or not the immune cells of the participant reacts when it comes into contact with the fish oils. The skin-prick-test involves the participants having their skin exposed to the fish oils. This is done by first exposing a tiny needle to the given fish oil, and then pricking the needle into the skin on the forearm of the participant. In this way, the immune cells of the skin is exposed to the fish oils. If an allergic reaction occurs, the pricked skin will swell and turn reddish. During the oral provocation, the participant is asked to ingest small, but increasing, doses of the fish oils over a period of 2 hours. The provocation will end when either an allergic reaction occurs or the participant has ingested a total dose of 5 mL fish oil.

Official Title
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Tolererer Fiske- og Skaldyrsallergikere Fiskeolietilskud? Et Klinisk Studie

Conditions
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Food Hypersensitivity

Intervention / Treatment
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* Dietary Supplement: Fish oil
* Dietary Supplement: Cod oil
* Dietary Supplement: Krill oil


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult (≥18 years old) Legally competent Understands Danish Exclusion Criteria: Current use of antihistamine, immunosuppressants, and/or anti-IgE-treatment that cannot be safely terminated during the study period The presence of severe diseases such as: Cardiovascular disease, asthma, cancer, liver disease, kidney disease, hematological diseases, neurological diseases, dementia, immunological diseases, and endocrine diseases Chronic urticaria Severe atopic eczema Pregnancy and/or breastfeeding Participation in another clinical study the previous three months Known excessive use of alcohol and/or substance abuse

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Tolerance test of fish oil, cod oil, and krill oil<br>All participants will have their tolerance of three different dietary supplements tested (fish oil, cod oil, and krill oil) using three methods: skin-prick-test, Basophil Histamine Release Assay, and oral provocation. | Dietary Supplement: Fish oil<br>* The tolerance of fish oil is tested using three methods: skin-prick-test, Basophil Histamine Release Assay, and oral provocation.<br>Dietary Supplement: Cod oil<br>* The tolerance of cod oil is tested using three methods: skin-prick-test, Basophil Histamine Release Assay, and oral provocation.<br>Dietary Supplement: Krill oil<br>* The tolerance of krill oil is tested using two methods: skin-prick-test and Basophil Histamine Release Assay. (We were unable to acquire enough liquid krill oil to perform oral provocation with this supplement).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Allergic reactions during fish oil provocation. | Presence of objective allergic symptoms (i.e. hives, redness, respiratory difficulties, and changes in blood pressure) during and two hours after the oral provocation. | At 2 hours after the provocation or at the end of the provocation if terminated early (in case of allergic reaction). | 
| Allergic reactions during cod oil provocation. | Presence of objective allergic symptoms (i.e. hives, redness, respiratory difficulties, and changes in blood pressure) during and two hours after the oral provocation. | At 2 hours after the provocation or at the end of the provocation if terminated early (in case of allergic reaction). | 
| Allergic reactions during krill oil provocation. | Presence of objective allergic symptoms (i.e. hives, redness, respiratory difficulties, and changes in blood pressure) during and two hours after the oral provocation. | At 2 hours after the provocation or at the end of the provocation if terminated early (in case of allergic reaction). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Skin-prick-test | The size of the hives are measured, if the diameter is >3 mm it is considered a positive result, if the negative and positive control are negative and positive, respectively | 15 minutes after the skin-prick-test has been administered. | 
| Basophil Histamine Release Assay | The histamine release when in contact with the fish oil is compared with the histamine release when in contact with the positive control: Phorbol 12-myristate 13-acetate (PMA) + ionomycin. A histamine release of >10% compared to the positive control is considered a positive result. | At baseline | 
| Subjective allergic symptoms during oral provocations | Subjective allergic symptoms (e.g. itchiness, throat irritation) are noted | At 2 hours after each provocation or at the end of the provocation if terminated early (in case of allergic reaction). | 
| Blood pressure during oral provocations | Blood pressure (mmHg) is measured to detect possible changes from baseline,indicating the severity of an allergic reaction | Change in blood pressure from baseline in case of allergic reaction | 
| Pulse during oral provocations | Pulse (beats pr. min) is measured to detect possible changes from baseline, indicating the severity of an allergic reaction | Change in blood pressure from baseline in case of allergic reaction | 
| Peak flow during oral provocations | Peak flow (liters pr. minute) is measured to detect possible changes from baseline, indicating the severity of an allergic reaction | Change in blood pressure from baseline in case of allergic reaction |