6533b7d0fe1ef96bd125ac14

RESEARCH PRODUCT

Serum eosinophil cationic protein as a potential biomarker for interleukin-5 antibody treatment in patients with severe uncontrolled eosinophilic asthma

subject

description

Serum eosinophil cationic protein (ECP) has been described as a marker reflecting activation of eosinophils in asthma, potentially correlating to airway inflammation. Our aim was to examine the role of serum ECP to predict treatment efficacy in asthmatics starting interleukin-5 antibody (anti-IL5) therapy. We evaluated 65 patients with severe, uncontrolled eosinophilic asthma (≥300 eosinophils per µl blood) before and approx. 4 months after initiation of anti-IL5 therapy with mepolizumab; 35 patients completed a 12 month follow-up. Evaluation of treatment efficacy included medical history, asthma questionnaires, physical examination, spirometry, exhaled NO and blood tests. Depending on the results, patients were grouped into treatment responders and non-responders. 65% (n=42) of our patients had elevated ECP levels (> 20 ng/ml) before anti-IL5 therapy. After 4 and 12 months ECP was normal in 80% and 82% of patients. 7 patients (11%) were counted as non-responders after 4 months, 2 patients experienced a loss of response between the 4 and 12 month evaluation. 22 patients with normal ECP values before therapy responded to treatment. In summary, the majority of patients with severe uncontrolled eosinophilic asthma had elevated serum ECP levels before initiation of anti-IL5 treatment, which decreased or normalized during therapy, irrespective of treatment response. Interestingly, a group of patients with normal ECP values before therapy still had a benefit from treatment. Further research will be conducted to evaluate possible confounders such as concomitant medication.