A Prospective, Clinical Study on Asymptomatic Sensitisation and Development of Allergic Rhinitis: High Negative Predictive Value of Allergological Testing

• Published in: International archives of allergy and immunology Vol. 155; no. 3; pp. 289 - 296
• Main Authors: Bodtger, Uffe, Assing, Kristian, Poulsen, Lars K.
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland Karger 01.01.2011
• Subjects: Adult; Allergens - immunology; Betula - immunology; Biological and medical sciences; Denmark - epidemiology; Female; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; Immunoglobulin E - blood; Immunopathology; Incidence; Male; Medical sciences; Middle Aged; Non tumoral diseases; Original Paper; Otorhinolaryngology. Stomatology; Poaceae - immunology; Pollen - immunology; Predictive Value of Tests; Prospective Studies; Rhinitis, Allergic, Seasonal - diagnosis; Rhinitis, Allergic, Seasonal - epidemiology; Rhinitis, Allergic, Seasonal - immunology; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; Sensitivity and Specificity; Skin Tests; Upper respiratory tract, upper alimentary tract, paranasal sinuses, salivary glands: diseases, semeiology; Young Adult; Denmark; Sensitisation to allergens; Immunoglobulin E; Allergen challenge; Seasonal allergic rhinitis; Risk assessment; Allergy; Immunopathology; Nose disease; Rhinitis; IgE; Risk; Asymptomatic; Medical screening; Prospective; Immunology; Risk factor; Predictive value; ENT disease; Allergen; Provocation test
• ISSN: 1018-2438; 1423-0097; 1423-0097
• DOI: 10.1159/000320758

Background: Asymptomatic aeroallergen sensitisation affects approximately 10% of Western adolescents and is an established risk factor for the development of respiratory allergy. The reported incidence is 2–20% annually. Previous studies are based on out-seasonal symptom recollection or selected populations, conferring bias towards higher incidence rates. Objective: The aim was to determine the incidence of onset of symptoms among clinically well-characterised asymptomatic, sensitised subjects compared with controls, and to evaluate the predictive values of common allergological tests. Methods: We performed a prospective, clinical, non-interventional, 2-year follow-up study on subjects (identified by population screening) with seasonal allergic birch or grass pollen rhinitis (n = 52), asymptomatic sensitisation to grass or birch (AS, n = 52) or non-atopic, healthy control subjects (n = 39). Experimental allergen susceptibility was assessed at inclusion and at follow-up by skin prick test, conjunctival challenge, intradermal late-phase reaction and measurement of specific IgE. Participants completed in-seasonal symptom and medication diaries during 2 subsequent seasons. Results: We observed an annual incidence rate of 5% for the onset of symptoms in the AS group (healthy control group 0%). At baseline, the AS group displayed intermediate experimental allergen susceptibility. Subjects developing symptoms had higher levels of specific IgE and larger late-phase reaction than those persistently asymptomatic. However, the positive predictive values were low (14–27%) in contrast to the negative predictive values (95–100%). Conclusion: In a well-characterised young population, asymptomatic aeroallergen sensitisation conferred a low risk for onset of symptoms during the 2-year follow-up. Persistent asymptomatic phenotype could be accurately predicted by negative results from simple allergological testing.