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

Definition of a Cut Off Value for S.P.A.T (Skin Prick Automated Test) Device Corresponding with Sensitisation to Both Birch and House Dust Mite Allergens, in Allergic Subjects

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.

Study Overview

• Status: Completed
• Conditions: Birch Pollen Allergy; House Dust Mite Allergy
• Intervention / Treatment: Device: Skin Prick Automated Test; Diagnostic test: Skin Prick Manual Test; Diagnostic test: Nasal Allergen Challenge

• Study Type: Interventional
• Enrollment (Actual): 75
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Strasbourg, France, 67000
    • Alyatec

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: HDM allergic patients; HDM allergic patients receive a nasal allergen provocation test with house dust mite allergens (der p and der f) to confirm the clinical relevance of the allergy. All patients receive a conventional skin prick test on the one arm and an automated test on the other arm.	Device: Skin Prick Automated Test; skin prick test to detection sensitisation to aeroallergens; Diagnostic test: Skin Prick Manual Test; skin prick test to detection sensitisation to aeroallergens; Diagnostic test: Nasal Allergen Challenge; nasal allergen challenge with either house dust mite allergens or birch pollen allergens
Experimental: Birch pollen allergic patients; Birch pollen allergic patients receive a nasal allergen provocation test with birch allergen (bet v) to confirm the clinical relevance of the allergy. All patients receive a conventional skin prick test on the one arm and an automated test on the other arm.	Device: Skin Prick Automated Test; skin prick test to detection sensitisation to aeroallergens; Diagnostic test: Skin Prick Manual Test; skin prick test to detection sensitisation to aeroallergens; Diagnostic test: Nasal Allergen Challenge; nasal allergen challenge with either house dust mite allergens or birch pollen allergens
Experimental: Non allergic patients; Non allergic patients did not receive a nasal allergen provocation test. All patients receive a conventional skin prick test on the one arm and an automated test on the other arm.	Device: Skin Prick Automated Test; skin prick test to detection sensitisation to aeroallergens; Diagnostic test: Skin Prick Manual Test; skin prick test to detection sensitisation to aeroallergens

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cutoff value with highest accuracy based on longest wheal diameter 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.	15 minutes after SPAT

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Accuracy of SPAT compared to conventional SPT	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.	15 minutes after SPAT

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intensity of allergy symptoms	The intensity of allergy symptoms will be evaluated by Lebel score and compared to wheal size after positive SPT.	15 minutes after SPAT
Intensity of allergy symptoms	The intensity of allergy symptoms will be evaluated by PNIF measurement and compared to wheal size after positive SPT.	15 minutes after SPAT
Longest wheal diameter measurement through S.P.A.T. web viewer compared to conventional ruler-based measurement	The concordance of wheals' size measurement by the S.P.A.T. web viewer and investigator/ trained and qualified staff member will be evaluated by correlation analysis.	15 minutes after SPAT
Time to perform skin prick test	The time to perform SPAT and conventional SPT will be evaluated by timing the duration between the start of executing the test and the end of the reading of the test (without timing the 15 minutes of waiting before reading).	at time of SPAT
Longest wheal diameter with S.P.A.T. compared to average diameter with conventional SPT	The longest diameter of wheal size measured with S.P.A.T. will be compared to the average (D+d/2) and the longest diameter of wheal size measured by conventional SPT.	15 minutes after SPAT
Cutoff value with highest accuracy based on wheal area	For the S.P.A.T., a cutoff value will be calculated similar to above by using the wheal area evaluated by F1 score.	15 minutes after SPAT
Accuracy of SPAT based on wheal area compared to conventional SPT	The non-inferiority of S.P.A.T accuracy using the wheal area compared to conventional SPT longest wheal diameter will be evaluated comparing the F1 score.	15 minutes after SPAT
Cutoff with highest accuracy based on histamine equivalent prick index	For the S.P.A.T., the HEP (histamine equivalent prick) index based on the wheal diameter and wheal area will be calculated. The cut-off value will be calculated similar to above. The HEP index is defined as allergen induced area/ histamine induced area or allergen induced diameter/histamine induced diameter.	15 minutes after SPAT
Accuracy of SPAT based on histamine equivalent prick index compared to conventional SPT	The non-inferiority of accuracy using the HEP-index compared to conventional SPT longest wheal diameter will be evaluated comparing the F1 score.	15 minutes after SPAT

Collaborators and Investigators

• Sponsor: Hippocreates
• Collaborators: Alyatec
• Investigators: Principal Investigator: Alina Gherasim, MD, Alyatec

Study record dates

Study Major Dates

• Study Start (Actual): September 17, 2024
• Primary Completion (Actual): October 21, 2024
• Study Completion (Actual): October 21, 2024

Study Registration Dates

• First Submitted: January 3, 2025
• First Submitted That Met QC Criteria: January 28, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 28, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Immune System Diseases; Respiratory Tract Diseases; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Nose Diseases; Otorhinolaryngologic Diseases; Rhinitis; Rhinitis, Allergic; Rhinitis, Allergic, Perennial; Dust Mite Allergy; Hypersensitivity; Rhinitis, Allergic, Seasonal
• Other Study ID Numbers: HIP-001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

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