Evaluation of an Adjusted Cutoff Value for S.P.A.T (Skin Prick Automated Test) Device in Allergic Subjects

Not Applicable

Completed

• Conditions: House Dust Mite Allergy; Birch Pollen Allergy

• Registration Number: NCT06803953
• Lead Sponsor: Hippocreates

Brief Summary

Skin prick test (SPT) is a first line diagnostic test to detect type I hypersensitivity in patients suspected of an inhalant allergy. A novel S.P.A.T. or Skin Prick Automated Test device has been developed to enable more standardised allergy testing. In two independent studies, Gorris and colleagues previously showed that test results after S.P.A.T. are less variable and more consistent compared to conventional skin prick testing (Gorris et al. Allergy. 2023; Seys et al. Rhinology 2024). In these studies conducted in volunteers, a cutoff value of 4.5 mm has been proposed based on the 97.5 percentile level of glycerol control wheals.

The current study aims to determine a cutoff value corresponding to the highest accuracy to discriminate between sensitized-allergic and non sensitized, non allergic subjects for both house dust mite and birch allergens.

Detailed Description

Not available

Study Timeline

• Study Start: 2024-09-17
• Primary Completion: 2024-10-21
• Study Completion: 2024-10-21
• Status Verified: 2025-01
• Study First Submitted: 2025-01-03
• Study First Submitted QC: 2025-01-28
• Last Update Submitted: 2025-01-28
• Study First Posted: 2025-01-31
• Last Update Posted: 2025-01-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 75

Inclusion Criteria

• Provide informed consent signed by study patient and investigator;
• Subjects with Health Social Identification Number;
• Allergic subjects with rhinitis with or without asthma and with or without conjunctivitis symptoms with proof of sensitisation to an inhalant allergy, either house dust mite ( Dermatophagoides pteronyssinus) or birch pollen by a positive skin prick test (SPT) with a wheal diameter ≥3 mm as compared to negative control. The clinical response against the culprit allergen will be assessed by a positive nasal allergen provocation test. (patients must not have clinical symptoms corresponding to both sensitization).
• Non-allergic subjects with proof of lack of sensitisation to any of the above referred allergens by a negative conventional skin prick test less than 2 years.
• Normal lung function as judged by investigator with FEV 1 and FEV 1/FVC ≥ 70% of predicted
• Willing and able to comply with clinic visits and study-related procedures;
• Able to understand and complete study-related questionnaires.

Exclusion Criteria

• Skin pathology like chronic or exuberant urticaria, dermographism, chronic dermatitis that needs daily treatment;
• Any skin abnormalities, which could negatively - in the opinion of the investigator - affect the test results, including large scars and tattoos on the forearm ;
• Patients with clinical symptoms corresponding to both sensitization to birch and house dust mite
• Use of antihistaminic medication < 7 days before the start of the study;
• Use of tricyclic antidepressants (antihistamine activity) < 7 days before the start of the study;
• Use of topical (on the forearm) or systemic corticoids < 7 days before the start of the study;
• Use of any monoclonal antibodies such as omalizumab, dupilumab, mepolizumab < 6 months before the start of the study;
• Use of oral systemic corticosteroids within 4 weeks prior to screening
• Use of intramuscular systemic corticosteroids within 3 months prior to screening
• Use of allergen immunotherapy for the allergen tested (<2 y) or another inhalant allergen;
• Pregnancy or breastfeeding;
• Women without highly effective contraception (hormonal contraception, intrauterine device, bilateral tubal occlusion/ligation, vasectomized partner, sexual abstinence) at least one month prior to inclusion and during the study;
• Incapacitated subjects;
• Subjects who do not speak the local language (French);
• Subjects who cannot read or write.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Cutoff value with highest accuracy based on longest wheal diameter after SPAT	15 minutes after SPAT	The cutoff value that corresponds to the highest F1 score of the accuracy of S.P.A.T. to detect sensitisation to both house dust mite and birch allergens by measuring the longest diameter of wheal size.

Secondary Outcome Measures

Name	Time	Method
Accuracy of SPAT compared to conventional SPT	15 minutes after SPAT	The non-inferiority of the accuracy of S.P.A.T. compared to the conventional SPT to detect sensitisation for both house dust mite and birch allergens in allergic and non-allergic subjects will be evaluated by comparing the F1 score of SPT and SPAT, measuring the longest diameter of wheal size.

Trial Locations

Locations (1)

Alyatec; 🇫🇷 Strasbourg, France