Design of an Optimally-Diagnostic Skin Test With Fewer Samples for Diagnosis of Sensitivity to Eight Allergens: a First-In-Human Study of Dose Escalation and Simultaneous Administration in Chinese Subjects

Background: Skin prick test is usually the preferred test in the diagnostic workup for allergic diseases, while there are few types of standardized allergen extracts available. Besides, standardization and composition give no assurance that the allergen extracts are within the concentration range that give the best chance of a true diagnosis. We designed a first-in-human diagnostic skin test with fewer samples to identify the optimally diagnostic concentration for eight standardized extracts from frequent native allergens, and to assess the safety of the eight allergens extracts’ simultaneous administration for supporting clinical allergen screening.Methods: Patients aged 18-45 years who had a history of allergic diseases were enrolled in this two-part open-label, parallel study: Study 1, each patient was given three concentrations of one allergen extract in turn. Study 2, each patient was given two concentrations of eight allergens extracts. Negative and positive controls were given each time the allergen was given. Both safety and sensitivity were evaluated to determine the optimally diagnostic concentration. Related-Samples Friedman's Two-Way Analysis was used to evaluate the difference of wheal diameter between different concentrations of each allergen. SPSS Statistics 26 was used for statistical analysis, and the significance test level was 0.05.Results: The sensitivity of allergens increased with the increasing of concentration. The eight investigated allergens showed good safety and did not reach the dose limit toxicity whether used alone or in combination. The optimally diagnostic concentration for eight aeroallergens were respectively determined as 33333 DU/mL, 12000 DU/mL, 8667 DU/mL, 50000 DU/mL, 40000 DU/mL, 3333 DU/mL, 7000 DU/mL, and 5000 DU/mL.Conclusions: This study designed a solution to determine the optimally diagnostic concentration with fewer subjects for further clinical trials of the eight investigated allergens and the results of this phase I clinical trial support further clinical research of investigated allergens. Trial registration: The trial was registered on www.chictr.org.cn (ChiCTR1900023952, 06/19/2019, retrospectively registered).