Amoxicillin AllergyTATNCT06409884
Diagnosing Drug Allergy: the T is the Key
A study testing T-cell activation test using intracellular markers in people with Amoxicillin Allergy, run by University Hospital, Antwerp at 1 site in Belgium.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 6 years and olderHealthy volunteers can take part
- Conditions the study is for
- Amoxicillin Allergy
- What is being tested?
- T-cell activation test using intracellular markers
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 300 participants
- Where
- 1 siteBelgium
- Study dates
- 21 May 2024to 30 Sep 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- 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
Who cannot join
- Patients who are lacking capacity or do not have an acceptable individual capable to provide informed consent
- Pregnant women
- Breastfeeding women
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Laura Peeters, Msc contact
Belgium1 site, 1 recruiting
- Recruiting
Antwerp University Hospital
Edegem, Antwerp, 2650
Didier Ebo, PhD, +32 3 821 46 62, Didier.Ebo@uza.be
Laura Peeters, Msc, +32 3 821 50 27, Laura.Peeters@uza.be
About this study
Official title: 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.
Read the 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.
- Conditions
- Amoxicillin Allergy
- Being tested
- T-cell activation test using intracellular markers
- Keywords
- Amoxicillin, Amoxicillin Allergy, Allergy, T-cells
- Medical subject headings
- Hypersensitivity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
T-cell activation test using intracellular markersDevice
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.
| Study group | Role | What they receive |
|---|---|---|
| Patients with a suspected amoxicillin allergy | Experimental | Patients with a suspected amoxicillin allergy for which the diagnostic work-up was performed at the hospital for the possible diagnosis of amoxicillin allergy. Receives: Device: T-cell activation test using intracellular markers |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sensitivity and specificity of the T-cell activation test
Sensitivity and specificity of the T-cell activation test during Study Visit 1 of patients with amoxicillin allergy and control subjects without amoxicillin allergy.
Measured: Baseline
Secondary outcomes (15)
Positive predictive value (PPV) and negative predictive value (NPV), accuracy and likelihood ratio (LR)
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.
Measured: Baseline
Percentage of cases with a positive TAT and positive IgE and/or skin test
Percentage of cases with a positive TAT and positive IgE and/or skin test
Measured: Baseline
Association between the severity of the index reaction and the performance of TAT in terms of odds ratio.
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.
Measured: Baseline
Association between the time since the index reaction and the performance of TAT in terms of odds ratio.
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.
Measured: Basline
Association between IDHR/non-IDHR and the performance of TAT in terms of odds ratio.
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.
Measured: Baseline
Association between the severity of the index reaction and the net percentage of intracellular T-cell activation marker CD154.
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.
Measured: Baseline
Association between the severity of the index reaction and the net percentage of intracellular T-cell activation marker IL-4.
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.
Measured: Baseline
Association between the severity of the index reaction and the net percentage of cytokine IFN-γ.
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.
Measured: Baseline
Association between the time since the index reaction and the net percentage of intracellular T-cell activation marker CD154.
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.
Measured: Baseline
Association between the time since the index reaction and the net percentage of intracellular T-cell activation marker IL-4.
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.
Measured: Baseline
Association between the time since the index reaction and the net percentage of cytokine IFN-γ.
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.
Measured: Baseline
Association between IDHR / non-IDHR and the net percentage of intracellular T-cell activation marker CD154.
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.
Measured: Baseline
Association between IDHR / non-IDHR and the net percentage of intracellular T-cell activation marker IL-4.
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.
Measured: Baseline
Association between IDHR / non-IDHR and the net percentage of cytokine IFN-γ.
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.
Measured: Baseline
Sensitivity and specificity of TAT in subgroup of cases and controls with immediate and nonimmediate reactors
Sensitivity and specificity of T-cell activation test in a subgroup of cases and controls with immediate and nonimmediate reactors
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 May 2024
- Study start21 May 2024
- Primary completion30 Sep 2027 (estimated)
- Study completion30 Sep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Amoxicillin AllergyStudies of the same condition, open and under way.
- More trials run by University Hospital, AntwerpThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital, Antwerp
- Sponsor type
- University, hospital or other
- Collaborators
- AZ Jan Palfijn Gent, Universiteit Antwerpen
- Responsible party
- Sponsor
- Investigators
- Didier Ebo, PhD, Principal investigator, University Hospital, Antwerp
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06409884
- Sponsor's protocol ID
- 003220
- Acronym
- TAT
- Status last verified
- May 2026
- First submitted
- 17 Apr 2024
- Last updated
- 14 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 14 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Diagnosing Drug Allergy the T is the Key
- ClinicalTrials.gov ID
- NCT06409884
- Acronym / sponsor ID
- TAT / 003220
- Conditions
- Amoxicillin Allergy
- Keywords
- Amoxicillin, Amoxicillin Allergy, Allergy, T-cells
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- University Hospital, AntwerpUniversity, hospital or other
- Collaborators
- AZ Jan Palfijn Gent, Universiteit Antwerpen
- Study start
- 21 May 2024 (actual)
- Primary completion
- 30 Sep 2027 (estimated)
- Study completion
- 30 Sep 2027 (estimated)
- First posted
- 10 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Patients with a suspected amoxicillin allergy | Experimental | Device: T-cell activation test using intracellular markersPatients with a suspected amoxicillin allergy for which the diagnostic work-up was performed at the hospital for the possible diagnosis of amoxicillin allergy. |
Who may qualify
- Ages
- 6 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (4 listed)
- 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
Key exclusion criteria (3 listed)
- Patients who are lacking capacity or do not have an acceptable individual capable to provide informed consent
- Pregnant women
- Breastfeeding women
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| T-cell activation test using intracellular markersA 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. | Device | Patients with a suspected amoxicillin allergy |
Primary outcome
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.
15 secondary outcomes
Positive predictive value (PPV) and negative predictive value (NPV), accuracy and likelihood ratio (LR)
Time frame: Baseline
Percentage of cases with a positive TAT and positive IgE and/or skin test
Time frame: Baseline
Association between the severity of the index reaction and the performance of TAT in terms of odds ratio.
Time frame: Baseline
Association between the time since the index reaction and the performance of TAT in terms of odds ratio.
Time frame: Basline
Association between IDHR/non-IDHR and the performance of TAT in terms of odds ratio.
Time frame: Baseline
Association between the severity of the index reaction and the net percentage of intracellular T-cell activation marker CD154.
Time frame: Baseline
Association between the severity of the index reaction and the net percentage of intracellular T-cell activation marker IL-4.
Time frame: Baseline
Association between the severity of the index reaction and the net percentage of cytokine IFN-γ.
Time frame: Baseline
Association between the time since the index reaction and the net percentage of intracellular T-cell activation marker CD154.
Time frame: Baseline
Association between the time since the index reaction and the net percentage of intracellular T-cell activation marker IL-4.
Time frame: Baseline
Association between the time since the index reaction and the net percentage of cytokine IFN-γ.
Time frame: Baseline
Association between IDHR / non-IDHR and the net percentage of intracellular T-cell activation marker CD154.
Time frame: Baseline
Association between IDHR / non-IDHR and the net percentage of intracellular T-cell activation marker IL-4.
Time frame: Baseline
Association between IDHR / non-IDHR and the net percentage of cytokine IFN-γ.
Time frame: Baseline
Sensitivity and specificity of TAT in subgroup of cases and controls with immediate and nonimmediate reactors
Time frame: Baseline
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 May 2026.
- Individual participant dataSharing planned: No
Related trials for Amoxicillin Allergy
Not yet recruiting
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Bronchitis, Acute, Community-acquired Pneumonia
Active, not recruitingPhase 1
The Implementation and Impact of an Allergy De-Labeling Program in the Emergency Department
Allergy Amoxicillin, Beta-lactam Allergy Labels
RecruitingPhase 3
Penicillin Allergy Delabeling After a One-Dose Versus Two-Dose Graded Direct Oral Challenge
Penicillin Allergy
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Laura Peeters, Msc contact
Didier Ebo, PhD principal investigator
University Hospital, Antwerp
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing T-cell activation test using intracellular markers in people with Amoxicillin Allergy, run by University Hospital, Antwerp at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 14 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Didier Ebo, PhD (+3238215027, Didier.Ebo@uza.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sensitivity and specificity of the T-cell activation test (time frame: Baseline). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 May 2026.