There is lack of evidence on the role of blood eosinophil count (BEC) as a predictor of treatment response in patients with chronic cough (CC). The study aimed to evaluate BEC as a predictor of treatment response in all non-smoking adults with CC and normal chest X-ray referred to cough clinic and in subgroup of patients with CC due to asthma or NAEB (non-asthmatic eosinophilic bronchitis).This prospective cohort study included 142 consecutive, non-smoking patients referred to our cough centre due to CC. The management of CC was performed according to the current recommendations. At least a 30 mm decrease of 100-mm visual analogue scale in cough severity and a 1.3 points improvement in Leicester Cough Questionnaire were classified as a good therapeutic response.There was a predominance of females (72.5%), median age 57.5 years with long-lasting, severe cough (median cough duration 60 months, severity 55/100 mm). Asthma, NAEB were diagnosed in 47.2% and 4.9% of patients, respectively. After 12–16 weeks of therapy, a good response to CC treatment was found in 31.0% of all patients. A weak positive correlation was demonstrated between reduction in cough severity and BEC (r=0.28, p<0.001). AUC for all patients with CC was 0.62 with the optimal BEC cut-off for prediction of treatment response set at 237 cells·µL−1 and for patients with CC due to asthma/NAEB was 0.68 (95% CI 0.55–0.81) with the cut-off at 150 cells·µL−1.BEC is a poor predictor of treatment response in adults with CC treated in the cough centre.
Baseline blood eosinophil count as a predictor of treatment response to the licensed dose of mepolizumab in severe eosinophilic asthma
