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NCT Number: NCT06409884

Diagnosing Drug Allergy: the T is the Key

The goal of this clinical trial is to validate a newly developed test in the diagnosis of patients with amoxicillin allergy (i.e. T-cell activation test). The main questions the study aims to assess are the reliability and applicability of this test. Participants will be asked to visit the hospital 1, 3 or 5 times during which blood is collected and when applicable, allergy skin testing is performed.

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Key information

Conditions

Amoxicillin Allergy Hypersensitivity Immune System Diseases

Age range

6 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

Drug allergy is a significant health issue with a serious medical and financial burden of mis- and overdiagnosis. Currently applied tests differ for immediate and nonimmediate drug allergy and have variable sensitivity and specificity. Therefore, correct diagnosis remains difficult and frequently requires potentially dangerous and time-consuming challenge tests. Drug-specific T-cells play a central role in initiation and maintenance of both immediate and nonimmediate drug allergy and can be studied in the lymphocyte transformation test (LTT). However, technical difficulties have hindered entrance of the LTT in mainstream use. The investigators' data indicates that flow-based intracellular trapping and staining of markers induced during activation (such as CD154 and cytokines) enables a rapid enumeration of rare drug-specific T-cells in the blood of patients with immediate and nonimmediate amoxicillin allergy. The ambition of this project is to validate a "one fits all" assay that meets the requirements of a safe, patient friendly, accessible, and performant test that could merits the status of a primary investigation in the diagnostic algorithms. Moreover, as the tests is cost effective, it could also become an attractive method for broader applications such as the delabelling of spurious allergies. This project will focus on allergy to amoxicillin.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Participants are eligible if they:

  • Are ≥ 6 years
  • Are capable of informed consent, or if appropriate, participants have an acceptable individual capable of giving consent on the participant's behalf (e.g. parent or guardian of a child under 18 years of age)
  • Have a suspected history of amoxicillin allergy

Exclusion criteria

  • Patients who are lacking capacity or do not have an acceptable individual capable to provide informed consent
  • Pregnant women
  • Breastfeeding women

Treatment and study plan

T-cell activation test using intracellular markers

Device

A blood sample will be taken which is needed for the T-cell activation test (TAT). The TAT will than be performed by trained laboratory personnel.

Primary outcomes

  1. Sensitivity and specificity of the T-cell activation test

    Time frame: Baseline

    Sensitivity and specificity of the T-cell activation test during Study Visit 1 of patients with amoxicillin allergy and control subjects without amoxicillin allergy.

Secondary outcomes

  1. Positive predictive value (PPV) and negative predictive value (NPV), accuracy and likelihood ratio (LR)

    Time frame: Baseline

    Positive predictive value (PPV) and negative predictive value (NPV), accuracy and likelihood ratio (LR) of the T-cell activation test in the diagnosis of amoxicillin allergy.

  2. Percentage of cases with a positive TAT and positive IgE and/or skin test

    Time frame: Baseline

    Percentage of cases with a positive TAT and positive IgE and/or skin test

  3. Association between the severity of the index reaction and the performance of TAT in terms of odds ratio.

    Time frame: Baseline

    The impact of severity of the index reaction on TAT-positivity will be studied in a logistic regression model. Odds ratios and 95% confidence intervals will be reported.

  4. Association between the time since the index reaction and the performance of TAT in terms of odds ratio.

    Time frame: Basline

    The impact of the time since the index reaction on TAT-positivity will be studied in a logistic regression model. Odds ratios and 95% confidence intervals will be reported.

  5. Association between IDHR/non-IDHR and the performance of TAT in terms of odds ratio.

    Time frame: Baseline

    The impact of IDHR/non-IDHR on TAT-positivity will be studied in a logistic regression model. Odds ratios and 95% confidence intervals will be reported.

  6. Association between the severity of the index reaction and the net percentage of intracellular T-cell activation marker CD154.

    Time frame: Baseline

    The impact of severity of the index reaction on the individual components of TAT will be studied in linear regression models, with respectively net percentage of intracellular T-cell activation markers CD154 as dependent variable. Unstandardized and standardized coefficients and standard errors will be reported.

  7. Association between the severity of the index reaction and the net percentage of intracellular T-cell activation marker IL-4.

    Time frame: Baseline

    The impact of severity of the index reaction on the individual components of TAT will be studied in linear regression models, with respectively net percentage of intracellular T-cell activation markers IL-4 as dependent variable. Unstandardized and standardized coefficients and standard errors will be reported.

  8. Association between the severity of the index reaction and the net percentage of cytokine IFN-γ.

    Time frame: Baseline

    The impact of severity of the index reaction on the individual components of TAT will be studied in linear regression models, with respectively net percentage of intracellular T-cell activation markers IFN-γ as dependent variable. Unstandardized and standardized coefficients and standard errors will be reported.

  9. Association between the time since the index reaction and the net percentage of intracellular T-cell activation marker CD154.

    Time frame: Baseline

    The impact of the time since the index reaction on the individual components of TAT will be studied in linear regression models, with respectively net percentage of intracellular T-cell activation markers CD154 as dependent variable. Unstandardized and standardized coefficients and standard errors will be reported.

  10. Association between the time since the index reaction and the net percentage of intracellular T-cell activation marker IL-4.

    Time frame: Baseline

    The impact of the time since the index reaction on the individual components of TAT will be studied in linear regression models, with respectively net percentage of intracellular T-cell activation markers IL-4 as dependent variable. Unstandardized and standardized coefficients and standard errors will be reported.

  11. Association between the time since the index reaction and the net percentage of cytokine IFN-γ.

    Time frame: Baseline

    The impact of time since the index reaction on the individual components of TAT will be studied in linear regression models, with respectively net percentage of intracellular T-cell activation markers IFN-γ as dependent variable. Unstandardized and standardized coefficients and standard errors will be reported.

  12. Association between IDHR / non-IDHR and the net percentage of intracellular T-cell activation marker CD154.

    Time frame: Baseline

    The impact of IDHR / non-IDHR on the individual components of TAT will be studied in linear regression models, with respectively net percentage of intracellular T-cell activation markers CD154 as dependent variable. Unstandardized and standardized coefficients and standard errors will be reported.

  13. Association between IDHR / non-IDHR and the net percentage of intracellular T-cell activation marker IL-4.

    Time frame: Baseline

    The impact of IDHR / non-IDHR on the individual components of TAT will be studied in linear regression models, with respectively net percentage of intracellular T-cell activation markers IL-4 as dependent variable. Unstandardized and standardized coefficients and standard errors will be reported.

  14. Association between IDHR / non-IDHR and the net percentage of cytokine IFN-γ.

    Time frame: Baseline

    The impact of IDHR / non-IDHR on the individual components of TAT will be studied in linear regression models, with respectively net percentage of intracellular T-cell activation markers IFN-γ as dependent variable. Unstandardized and standardized coefficients and standard errors will be reported.

  15. Sensitivity and specificity of TAT in subgroup of cases and controls with immediate and nonimmediate reactors

    Time frame: Baseline

    Sensitivity and specificity of T-cell activation test in a subgroup of cases and controls with immediate and nonimmediate reactors

Other outcomes

  1. Sensitivity of TAT 1 year and 3 years after diagnosis

    Time frame: After 1 and 3 years

    Sensitivity of TAT 1 year and 3 years after diagnosis of patients with amoxicillin allergy

  2. Evolution TAT-components over time

    Time frame: After 1 and 3 years

    Evolution TAT-components over time in patients with amoxicillin allergy

Study contacts

Contact information is provided by the study sponsor or research team.

Didier Ebo, PhD

CONTACT

[email protected]

+3238215027

Laura Peeters, Msc

CONTACT

[email protected]

Sponsors and collaborators

Lead sponsor

University Hospital, Antwerp

Other

Collaborators

  • AZ Jan Palfijn Gent
  • Universiteit Antwerpen

Registry information

Official study title

Diagnosing Drug Allergy the T is the Key

Acronym: TAT

Important dates

Study start
2024
Primary completion
2027
Study completion
2027
First posted
May 10, 2024
Registry last updated
May 14, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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