Optimizing the Diagnostic Approach to Cephalosporin Allergy Testing

Study Purpose

Cephalosporin antibiotics are commonly used but can result in allergic reactions and anaphylaxis. There is no clear diagnostic approach for cephalosporin-allergic patients, and guidance for the use of other antibiotics in allergic patients is based on side chain chemical similarity and limited skin testing evidence. This project includes a clinical trial and mechanistic studies to optimize the approach to cephalosporin allergy and advance future diagnostics.

Recruitment Criteria

Accepts Healthy Volunteers Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms	No
Study Type An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes. An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes. Searching Both is inclusive of interventional and observational studies.	Interventional
Eligible Ages	18 Years - 70 Years
Gender	All

More Inclusion & Exclusion Criteria

Inclusion Criteria:

1. Age 18-70 years old. 2. Reaction history consistent with a potential immediate hypersensitivity reaction (pruritus, urticaria, erythema, angioedema, bronchospasm, wheezing, shortness of breath, and anaphylaxis) to cefazolin, ceftazidime, ceftriaxone, cefepime, cephalexin, cefaclor, cefadroxil, cefuroxime, cefpodoxime, cefdinir, or cefixime. 3. English speaking or non-English speaking with translation services available.

Exclusion Criteria:

1. Severe concomitant medical condition (e.g., unstable coronary artery disease, congestive heart failure, severe chronic obstructive pulmonary disease, poorly controlled asthma, chronic renal failure, cirrhosis, or end-stage liver disease.) 2. History of Clostridioides difficile infection. 3. Chronic spontaneous urticaria or systemic mastocytosis. 4. Incident reaction required cardiopulmonary resuscitation. 5. Reaction to 2 or more cephalosporin antibiotics. 6. Active infection or systemic antibiotic treatment within 7 days. 7. Treatment with systemic antihistamines or corticosteroids within 7 days. 8. Treatment with omalizumab or dupilumab within 60 days. 9. Significant immunosuppression. 10. Treatment with a beta-blocker or ACE inhibitor within 7 days. 11. Use of investigational drugs within 60 days of participation. 12. Abnormal vital signs or unstable physical exam at Visit 1. 13. Prison or jail inmates, pregnant women, severe cognitive impairment. 14. Current, diagnosed, mental illness or current, diagnosed, or self-reported drug or alcohol abuse that, in the opinion of the investigator, would interfere with the participant's ability to comply with study requirements. 15. Past or current medical problems or findings from physical examination or laboratory testing that are not listed above, which, in the opinion of the investigator, may pose additional risks from participation in the study, may interfere with the participant's ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study. 16. Inability or unwillingness of a participant to give written informed consent or comply with study protocol

Trial Details

Trial ID: This trial id was obtained from ClinicalTrials.gov, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.	NCT06406114
Phase Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans. Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data. Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs. Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.	Phase 2
Lead Sponsor The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.	Massachusetts General Hospital
Principal Investigator The person who is responsible for the scientific and technical direction of the entire clinical study.	Kimberly G Blumenthal, MD, MScDavid A Khan, MD
Principal Investigator Affiliation	Massachusetts General HospitalUniversity of Texas Southwestern Medical Center
Agency Class Category of organization(s) involved as sponsor (and collaborator) supporting the trial.	Other, NIH
Overall Status	Not yet recruiting
Countries	United States
Conditions The disease, disorder, syndrome, illness, or injury that is being studied.	Drug Allergy, Cephalosporin Allergy, Drug Hypersensitivity, Antibiotic Allergy, Beta Lactam Adverse Reaction, Drug-Induced Anaphylaxis, Cephalosporin Reaction

Additional Details

Background: In the United States, beta-lactam antibiotics are the leading cause of allergic reactions. Cephalosporin antibiotics, in particular, are the most common cause of drug-induced anaphylaxis and perioperative allergy. For penicillin allergy, the mechanism of allergy and the antigenic determinants are known; validated penicillin skin testing followed by drug challenge has a 100% negative predictive value to exclude an immunoglobulin (Ig)E-mediated reaction. For cephalosporin allergy, the antigenic determinants and mechanism are not known, and skin testing is not validated. The diagnostic test characteristics of skin testing with native cephalosporins remain unclear with no sensitivity nor specificity reported. Although beta-lactam cross-reactivity has been hypothesized to be from the similarity of the R1 side chains, rather than the beta-lactam ring, cross-reactivity estimates among beta-lactams vary. Furthermore, it is not known whether the variance in cross-reactivity is due to true allergy versus sensitization based on positive skin testing, given that drug challenges were not performed on skin-test-positive patients. While an IgE mechanism is assumed for cephalosporin allergy and supported by skin testing that has been positive, the biology has yet to be characterized, and some cephalosporin anaphylaxis can occur on the first exposure, which is inconsistent with an IgE mechanism. Given the complexity of cephalosporin structures and potential epitopes, there may be several distinct biologic pathways involved in cephalosporin allergy. Future diagnostics in cephalosporin allergy are reliant on determination of these biological pathways and finding key haptens. Aims: Current national practice guidelines related to cephalosporin allergy assessment are considered conditional and based on low-quality evidence. The overall goal is to identify the optimal diagnostic approach to cephalosporin allergy and determine beta-lactam cross-reactivity, while discovering the mechanism and antigenic determinants of cephalosporin allergy to advance future diagnostics. The investigators will do this through a clinical trial that will generate empirical evidence through novel trial procedures, double-blind skin testing, and double-blind placebo-controlled drug challenges. Specific aims are: 1) To determine the optimal approach to cephalosporin allergy evaluation; 2) To assess beta-lactam cross-reactivity in cephalosporin-allergic individuals; and 3) To investigate the antigenic determinants and mechanism of cephalosporin allergy. Study Overview: Enrolled and consented subjects will attend visit 1 for baseline screening, sample collection, double-blind skin testing to a beta-lactam panel, and a double-blind placebo-controlled challenge to their culprit cephalosporin antibiotic. Results of the culprit cephalosporin challenge determine subject's study timeline. Subjects confirmed as non-allergic to their culprit cephalosporin will return for visit 2 for venipuncture and blood collection, ending their participation in the study. Subjects who are confirmed as allergic to their culprit at visit 1 will return for three additional visits; visits 2 and 3 will include double-blind placebo-controlled challenges to a similar side chain and dissimilar side chain cephalosporin (as compared to the side chain of their culprit) to assess cross-reactivity. The order of these two challenges is randomized between visit 2 and 3, and the order of whether a similar or dissimilar side chain cephalosporin is challenged first (in visit 2) differentiates the comparator arms of this study. In visit 4, subjects from both comparator arms will undergo a double-blind placebo-controlled challenge to a penicillin to assess cross-reactivity between cephalosporins and penicillins. Completion of this penicillin challenge marks the end of participation for confirmed-allergic subjects. Venipuncture and sample collection will occur at each visit.

Arms & Interventions

Arms

Experimental: Similar cephalosporin first

In visit 2, confirmed-allergic subjects will have a double-blind placebo-controlled drug challenge to a similar side chain cephalosporin, followed by a double-blind placebo-controlled challenge to a dissimilar side chain cephalosporin in visit 3. The randomization of which cephalosporin (similar or dissimilar side chain) is challenged in visits 2 and 3 differentiates the two arms.

Experimental: Dissimilar cephalosporin first

In visit 2, confirmed-allergic subjects will have a double-blind placebo-controlled drug challenge to a dissimilar side chain cephalosporin, followed by a double-blind placebo-controlled challenge to a similar side chain cephalosporin in visit 3. The randomization of which cephalosporin (similar or dissimilar side chain) is challenged in visits 2 and 3 differentiates the two arms.

Interventions

Drug: - Beta-lactam antibiotic (cefazolin, cefuroxime, cefotaxime, ceftazidime, ceftriaxone, cefepime, pre-pen, penicillin G, ampicillin, and histamine) double-blind skin testing

Percutaneous and intradermal skin testing will be performed in all participants. Concentrations for percutaneous testing; cefazolin (330 mg/ml), cefuroxime (90 mg/ml), cefotaxime (100 mg/ml), ceftazidime (100 mg/ml), ceftriaxone (100 mg/ml), cefepime (200 mg/ml), pre-pen (undiluted), penicillin G (10,000 U/ml), ampicillin (20 mg/ml) and histamine (6 mg/ml). Concentrations for the first intradermal testing; cefazolin (3.3mg/ml), cefuroxime (1 mg/ml), cefotaxime (1 mg/ml), ceftazidime (1 mg/ml), ceftriaxone (1 mg/ml), cefepime (2 mg/ml), pre-pen (undiluted), penicillin G (1000 U/ml), ampicillin (20 mg/ml), and histamine (0.1 mg/ml). Concentrations for the second intradermal testing; cefazolin (33mg/ml), cefuroxime (10 mg/ml), cefotaxime (10 mg/ml), ceftazidime (10 mg/ml), ceftriaxone (10 mg/ml), cefepime (20 mg/ml), pre-pen (undiluted), penicillin G (10,000 U/ml), ampicillin (20 mg/ml) and histamine (0.1 mg/ml). Histamine and saline will be used as positive and negative controls.

Drug: - Culprit cephalosporin (cefazolin, ceftazidime, ceftriaxone, cefepime, cephalexin, cefaclor, cefadroxil, cefuroxime, cefpodoxime, cefdinir, or cefixime) double-blind placebo-controlled drug challenge

After double-blind skin testing, participants will undergo a 3-step double-blind placebo-controlled drug challenge to their culprit cephalosporin (the cephalosporin they are suspected to be allergic to, either cefazolin, ceftazidime, ceftriaxone, cefepime, cephalexin, cefaclor, cefadroxil, cefuroxime, cefpodoxime, cefdinir, or cefixime). The challenges are 1:1 randomized to the order of active drug versus placebo. In Step 1, participants will receive 1:1000 of a full dose of either the culprit drug or placebo, followed by a 30-minute observation period. In Step 2, participants will receive 1:50 of a full dose of either, followed by another 30-minute observation period. In Step 3, participants are administered the full dose of either agent, followed by a 60-minute observation period. The same testing process is repeated for the second challenge.

Drug: - Similar cephalosporin (cefepime, ceftriaxone, cefaclor, cephalexin, cefixime, or cefdinir) antibiotic double-blind placebo-controlled drug challenge

Participants will undergo a 3-step double-blind placebo-controlled drug challenge to a cephalosporin antibiotic that shares a similar side chain with their culprit. This will be cefepime for those allergic to ceftriaxone, cefaclor for those allergic to cephalexin, cefixime for those allergic to cefdinir, cefdinir for those allergic to cefixime, cephalexin for those allergic to cefaclor or cephadroxil, and ceftriaxone for those allergic to cefepime, cefuroxime, or cefpodoxime. The challenges are 1:1 randomized to the order of active drug versus placebo. In Step 1, participants will receive 1:1000 of a full dose of either the culprit drug or placebo, followed by a 30-minute observation period. In Step 2, participants will receive 1:50 of a full dose of either, followed by another 30-minute observation period. In Step 3, participants are administered the full dose of either agent, followed by a 60-minute observation period. The same testing process is repeated for the second challenge.

Drug: - Dissimilar cephalosporin (ceftriaxone or cefazolin) antibiotic double-blind placebo-controlled drug challenge

Participants will undergo a 3-step double-blind placebo-controlled drug challenge to a cephalosporin antibiotic that has a dissimilar side chain to their culprit. This will be ceftriaxone for those allergic to cefazolin, and cefazolin for those allergic to any other cephalosporin. The challenges are 1:1 randomized to the order of active drug versus placebo. In Step 1, participants will receive 1:1000 of a full dose of either the culprit drug or placebo, followed by a 30-minute observation period. In Step 2, participants will receive 1:50 of a full dose of either, followed by another 30-minute observation period. In Step 3, participants are administered the full dose of either agent, followed by a 60-minute observation period. The same testing process is repeated for the second challenge.

Drug: - Amoxicillin double-blind placebo-controlled drug challenge

Participants will optionally undergo a 3-step double-blind placebo-controlled drug challenge to Amoxicillin. The challenges are 1:1 randomized to the order of active drug versus placebo. In Step 1, participants will receive 1:1000 of a full dose of either the culprit drug or placebo, followed by a 30-minute observation period. In Step 2, participants will receive 1:50 of a full dose of either, followed by another 30-minute observation period. In Step 3, participants are administered the full dose of either agent, followed by a 60-minute observation period. The same testing process is repeated for the second challenge. The order of challenge to similar vs. dissimilar cephalosporin will be randomized as well.

Contact a Trial Team

If you are interested in learning more about this trial, find the trial site nearest to your location and contact the site coordinator via email or phone. We also strongly recommend that you consult with your healthcare provider about the trials that may interest you and refer to our terms of service below.

Mayo Clinic Arizona, Scottsdale, Arizona

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Mayo Clinic Arizona

Scottsdale, Arizona, 14607

Site Contact

Alexei Gonzalez-Estrada, MD

[email protected]

904-953-2451

University of California, San Francisco, San Francisco, California

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