PT - JOURNAL ARTICLE AU - Claire A. Butler AU - Alan J. McMichael AU - Kirsty Honeyford AU - Louise Wright AU - Jayne Logan AU - Joshua Holmes AU - John Busby AU - Catherine E. Hanratty AU - Freda Yang AU - Steven J. Smith AU - Kirsty Murray AU - Rekha Chaudhuri AU - Liam G. Heaney ED - , TI - Utility of fractional exhaled nitric oxide suppression as a prediction tool for progression to biologic therapy AID - 10.1183/23120541.00273-2021 DP - 2021 Jul 01 TA - ERJ Open Research PG - 00273-2021 VI - 7 IP - 3 4099 - http://openres.ersjournals.com/content/7/3/00273-2021.short 4100 - http://openres.ersjournals.com/content/7/3/00273-2021.full SO - erjor2021 Jul 01; 7 AB - Rationale: The utility of fractional exhaled nitric oxide (FENO) suppression (FeNOSuppT) to identify non-adherence to inhaled corticosteroid (ICS) treatment has previously been reported, but whether it can predict clinical outcome remains unclear.Objectives: We examined the utility of FeNOSuppT in prediction of progression to biologic agents or discharge from specialist care.Methods: FeNOSuppT was measured at home using remote monitoring technology of inhaler use alongside daily FENO measurement over 7 days. Long-term clinical outcomes in terms of progression to biologic agent or discharge from specialist care were compared for non-suppressors and suppressors.Measurements and main results: Of the 162 subjects, 135 successfully completed the test with 81 (60%) positive FENO suppression tests. Subjects with a negative FeNOSuppT were more likely to proceed to biologic therapy (39 of 54 patients, 72%) compared to those with a positive FeNOSuppT (35 of 81 patients, 43%, p=0.001). In subjects with a positive FeNOSuppT, predictors of progression to biologic therapy included higher dose of maintenance steroid at initial assessment and prior intensive care unit admission. These subjects had a significant rise in FENO between post-suppression test and follow-up (median, 33 (IQR 25–55) versus 71 (IQR 24–114); p=0.009), which was not explained by altered corticosteroid dose.Conclusions: A negative FeNOSuppT correlates with progression to biologic therapy. A positive FeNOSuppT, with subsequent maintenance of “optimised” FENO, predicts a subgroup of patients in whom asthma control is preserved with adherence to high-dose ICS/long-acting β2 agonist and who can be discharged from specialist care.A positive FENO suppression test can identify non-adherence. Maintenance of “optimised” FENO by sustained adherence to inhaled therapy predicts patients who are likely to maintain control with high-dose inhaled therapy without the need for biologics. https://bit.ly/3cRpQ5B