Diagnosing Drug Allergy: the T is the Key (TAT)

May 11, 2026 updated by: University Hospital, Antwerp

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

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.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
300

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Belgium
    • Antwerp
      • Edegem, Antwerp, Belgium, 2650
        • Recruiting
        • Antwerp University Hospital
        • Contact:
        • Contact:
        • Principal Investigator:
          • Didier Ebo, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Patients with a suspected amoxicillin allergy
Patients with a suspected amoxicillin allergy for which the diagnostic work-up was performed at the hospital for the possible diagnosis of amoxicillin allergy.
Device: T-cell activation test using intracellular markers
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.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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.
Baseline

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
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.
Baseline
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
Baseline
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.
Baseline
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.
Basline
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.
Baseline
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.
Baseline
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.
Baseline
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.
Baseline
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.
Baseline
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.
Baseline
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.
Baseline
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.
Baseline
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.
Baseline
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.
Baseline
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
Baseline

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
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
After 1 and 3 years
Evolution TAT-components over time
Time Frame: After 1 and 3 years
Evolution TAT-components over time in patients with amoxicillin allergy
After 1 and 3 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Hospital, Antwerp

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Universiteit Antwerpen
AZ Jan Palfijn Gent

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Didier Ebo, PhD, University Hospital, Antwerp

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 21, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 17, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 7, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 10, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 14, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 11, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 003220

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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