Food Hypersensitivity, Shellfish Allergy
Conditions
Keywords
Oral Food Challenge, Skin Prick Test, Tropomyosin, Hemocyanin, Specific IgE, Recombinant Allergen, Shellfish Allergy, Children, Food Hypersensitivity, Shrimp Allergy
Brief summary
This study will evaluate whether blood tests that measure IgE antibodies to two shrimp proteins, tropomyosin and hemocyanin, can help diagnose shrimp allergy in children. Children with suspected IgE-mediated shrimp allergy will undergo oral food challenge, skin prick testing, and blood sampling. Oral food challenge results will be used as the reference standard to determine whether these tests can accurately identify true shrimp allergy and help improve diagnosis in clinical practice.
Detailed description
Shrimp allergy is an important cause of IgE-mediated food allergy in children, and diagnosis remains challenging because conventional tests may not reliably distinguish true clinical allergy from sensitization or cross-reactivity. Oral food challenge (OFC) remains the reference standard, but it is time-consuming, resource-intensive, and may trigger significant allergic reactions. This interventional diagnostic study will enroll children with suspected IgE-mediated shrimp allergy. Participants will undergo OFC according to the study protocol, together with skin prick testing and blood sampling for measurement of specific IgE to recombinant tropomyosin and hemocyanin. To standardize the diagnostic procedure, OFC will be performed using black tiger shrimp (Penaeus monodon) in all participants. Additional OFCs using other shrimp species may be performed when the clinical history suggests reactions to a different shrimp species. OFC results will be used to classify participants as shrimp allergic or shrimp tolerant. The study will estimate the proportion of true shrimp allergy among children with suspected shrimp allergy and evaluate the diagnostic performance of recombinant tropomyosin- and hemocyanin-specific IgE, alone and in combination with clinical history and skin prick test results. The findings are expected to support more accurate molecular diagnosis of shrimp allergy in children and help optimize the indication for OFC in clinical practice in Vietnam.
Interventions
DIAGNOSTIC_TESTOral Food Challenge (OFC)
Oral food challenge with shrimp performed according to the study protocol to confirm or exclude IgE-mediated shrimp allergy in children with suspected shrimp allergy. To standardize the challenge material, black tiger shrimp (Penaeus monodon) will be used in all participants. Additional oral food challenges using other shrimp species may be performed when the clinical history suggests reactions to a different shrimp species. The oral food challenge result serves as the reference standard for diagnostic evaluation in this study.
DIAGNOSTIC_TESTSkin Prick Test
Skin prick testing performed as part of the diagnostic evaluation in children with suspected IgE-mediated shrimp allergy.
DIAGNOSTIC_TESTRecombinant Tropomyosin- and Hemocyanin-Specific IgE Measurement
Blood testing to measure specific IgE to recombinant tropomyosin and hemocyanin as part of the diagnostic evaluation of suspected shrimp allergy.
Sponsors
University of Medicine and Pharmacy at Ho Chi Minh City
Children's Hospital Number 1, Ho Chi Minh City, Vietnam
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Masking description
No masking is used for study assignment. However, laboratory personnel performing recombinant tropomyosin- and hemocyanin-specific IgE measurements are independent of the clinical team and are blinded to participants' oral food challenge results at the time of laboratory assessment.
Intervention model description
All enrolled children with suspected IgE-mediated shrimp allergy will undergo the same study procedures, including oral food challenge, skin prick testing, blood sampling, and measurement of recombinant tropomyosin- and hemocyanin-specific IgE.
Eligibility
Sex/Gender
ALL
Age
1 Years to 16 Years
Healthy volunteers
No
Inclusion criteria
* Children aged 1 to 16 years. * Evaluated at the Allergy Unit of Children's Hospital 1. * Clinical history suggestive of IgE-mediated shrimp allergy based on EAACI 2023 criteria, including at least 1 typical allergic symptom (urticaria, angioedema, vomiting, abdominal pain, diarrhea, cough, wheezing, dyspnea, or hypotension), symptom onset within 2 hours after shrimp ingestion, and recurrence on at least 2 separate exposures. * Parent or legal guardian able to provide written informed consent; child assent obtained when appropriate.
Exclusion criteria
* Acute illness at the time of enrollment or challenge, including acute respiratory infection, acute gastrointestinal infection, or acute asthma exacerbation. * Severe chronic disease, including malignancy, severe liver or kidney disease, primary immunodeficiency, or significant heart disease affecting hemodynamic status. * Mental or behavioral disorder that prevents completion of study procedures. * Use of immunosuppressive medication (oral corticosteroids, cytotoxic drugs, or biologic agents) within 4 weeks before enrollment, or intravenous immunoglobulin within the previous 3 months.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Oral Food Challenge-Confirmed IgE-Mediated Shrimp Allergy | At the time of the oral food challenge during the baseline diagnostic evaluation | Participants will be classified as having true IgE-mediated shrimp allergy if the oral food challenge is positive according to the study protocol. A negative oral food challenge indicates shrimp tolerance. Oral food challenge results will be used as the reference standard for subsequent diagnostic performance analyses. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Diagnostic Accuracy of Recombinant Tropomyosin-Specific IgE for Oral Food Challenge-Confirmed Shrimp Allergy | During the baseline diagnostic evaluation | Diagnostic performance of recombinant tropomyosin-specific IgE will be evaluated against oral food challenge results, including receiver operating characteristic analysis, area under the curve, optimal cutoff, sensitivity, specificity, positive predictive value, and negative predictive value. |
| Diagnostic Accuracy of Recombinant Hemocyanin-Specific IgE for Oral Food Challenge-Confirmed Shrimp Allergy | During the baseline diagnostic evaluation | Diagnostic performance of recombinant hemocyanin-specific IgE will be evaluated against oral food challenge results, including receiver operating characteristic analysis, area under the curve, optimal cutoff, sensitivity, specificity, positive predictive value, and negative predictive value. |
| Diagnostic Accuracy of a Combined Model Incorporating Recombinant Tropomyosin-Specific IgE, Recombinant Hemocyanin-Specific IgE, Clinical History, and Skin Prick Test | During the baseline diagnostic evaluation | A combined diagnostic model using recombinant tropomyosin-specific IgE, recombinant hemocyanin-specific IgE, clinical history suggestive of shrimp allergy, and skin prick test results will be evaluated against oral food challenge results. Model performance will include receiver operating characteristic analysis and area under the curve. |
Countries
Vietnam
Contacts
CONTACTNgoc Thi Nguyen, MD
PRINCIPAL_INVESTIGATORTu HK Trinh, MD, PhD
University of Medicine and Pharmacy at Ho Chi Minh City
Outcome results
None listed