TY - JOUR T1 - Importance of type and degree of IgE sensitisation for defining fractional exhaled nitric oxide reference values JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2021.PA3706 VL - 58 IS - suppl 65 SP - PA3706 AU - Suneela Zaigham AU - Xingwu Zhou AU - Magnus Molin AU - Anders Sjölander AU - Robert Movérare AU - Christer Janson AU - Andrei Malinovschi Y1 - 2021/09/05 UR - http://erj.ersjournals.com/content/58/suppl_65/PA3706.abstract N2 - Background: Fractional exhaled nitric oxide (FENO) is a marker of type 2 airways inflammation used in clinical practice in asthma. There is a need to define reference values for FENO and this is within the scope of a newly started Global Lung Function Initiative task force.Aim: We aimed to study the effects of the degree and type of IgE sensitisation on FENO and hypothesised that both the degree and type of IgE sensitisation would influence FENO levels, with special emphasis on the upper limit of normal (ULN).Methods: FENO was measured in 1855 non-smoking, respiratory healthy subjects from the Swedish CArdioPulmonary bioImage Study. Atopy was defined by a positive ImmunoCAP Phadiatop test (≥0.35 PAU/l, Phadia AB, Uppsala Sweden), measuring IgE antibodies to a mix of aeroallergens. Atopic subjects (n=424) were further IgE-assessed to individual perennial (cat/mite) or seasonal allergens (birch) and compared to non-atopic subjects (n=1431)Results: IgE sensitisation to cat and/or mite resulted in both higher median FENO and ULN compared to non-atopic subjects (FENO (ppb): 20 vs 15 and 50 vs 33, p<0.001). Sensitisation to only birch was not associated with significantly higher FENO (18 vs 15 and 38 vs 33, p=0.12). Atopic subjects with IgE levels in the highest Phadiatop tertile (>3.75 PAU/l) had higher median FENO and ULN compared to non-atopic subjects (20 vs 15 and 56 vs 33, p<0.0001).Conclusion: IgE sensitisation to perennial allergens and a higher degree of IgE sensitisation towards a mix of aeroallergens result in higher FENO levels than in non-atopic subjects. Both the degree and type of IgE sensitisation should be considered in generating reference values for FENO.FootnotesCite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA3706.This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only). ER -