S19 Use of sputum eosinophils to help guide management in a tertiary referral cough centre

<h3>Introduction</h3> Patients suffering from refractory chronic cough often present with symptoms attributable to co-morbidities including asthma, Gastro-Oesophageal Reflux Disease, Intermittent Laryngeal Obstruction, eosinophilic bronchitis. Teasing out respective contribution takes several months and sometimes requires bronchoscopy with associated risk to patients and cost implications. Inflammation and infection are treatable traits in chronic cough. Sputum assessment including differential cell count (DCC) might help tailor management for those patients with normal FeNO, blood eosinophils count and in whom bronchoscopy is not indicated. <h3>Aims</h3> To assess if sputum eosinophils and neutrophils measurement leads to a change in clinical management of cough patients. <h3>Methods</h3> Patients with refractory chronic cough for whom bronchoscopy was not indicated, and who were able to produce sputum (spontaneously or by induction) were referred for airway inflammation assessment. Clinical diagnosis, medication, blood eosinophils, FeNO, IgE, sputum DCC, cough scores (0–10: 0=no cough; 10=worst possible cough) and outcome of clinical management post DCC were recorded. <h3>Results</h3> Fourteen patients provided sputum samples (1 induced), one of which provided a follow-up sample (table 1). Half of the patients referred for sputum DCC had a clinical contra-indication to bronchoscopy (high blood pressure (n=3), myocardial infarction (n=1), airways collapsibility (n=1), allergy to lidocaine (n=1). Sputum DCC supported a change in diagnosis and/or management in all patients: Clinical diagnosis was changed for 6 patients (Eosinophilic bronchitis added (3), ILD and ILO added (1 each), asthma ruled out (1)), one patient was discharged. Ninety-three percent of sputum DCC (14/15) resulted in a change in therapy (ICS/OCS (n=4), azithromycin (n=9), Hypertonic saline (n=1)). Over half (n=7) of the 13 patients who rated/scored their cough post DCC reported an improvement in cough symptoms following a change in therapy supported by sputum assessment. <h3>Conclusions</h3> Clinical management or diagnosis was adjusted for 100% patients post DCC with cough improvement for half of them. Sputum DCC investigation should be considered in addition to routine culture in patients with refractory chronic cough where inflammation is suspected and can provide a useful alternative when bronchoscopy is not indicated.