Study of Blood Eosinophils and Plasma Periostin as Biomarkers for Response of COPD Patients to ICS/LABA Treatment

Background: Eosinophilic airway inflammation has been detected in up to 40% of chronic obstructive pulmonary disease (COPD) patients during stable periods of the disease and increased sputum eosinophil count was associated with better lung function, more future exacerbations, and symptoms that responded better to treatment with inhaled and oral corticosteroids. The aim of this work was to investigate the relationship of blood eosinophils and plasma Periostin with lung function changes related to ICS and long-acting beta2- agonist combination treatment in stable COPD patients for three months. Methods: This prospective experimental study was carried out on 50 COPD patients with post bronchodilator FEV1/ FVC ratio <70%. Patient collected from outpatient clinics of Chest Department Tanta University Hospitals, Tanta Chest Hospital and Mansoura Chest Hospital from February 2020 to February 2022.Patients subjected to complete history taking, clinical examinations including general and local examinations and laboratory investigations [complete blood count to assess eosinophilic count, arterial blood gases and plasma periostin] and spirometry were done for all patients pre and post treatment. All patients received three months of treatment with a fixed dose of combined inhalers of ICS and LABA and then they were classified into FEV1 responder and FEV1 non-responder according to improvement in FEV1 at least 12% and 200ml from base line of three months of combined treatment with ICS/LABA. Results: Blood eosinophil count had a significant positive correlation with smoking index (pack/year), negative correlations with FEV1% of predicted, FEV1 actual value (L), FEV1/FVC ratio. Plasma periostin concentration had significant positive correlation with blood eosinophil count, COPD grade, FVC actual value (L) and significant negative correlations with FEV1% of predicted, FEV1 actual value (L) and FEV1/FVC. Cut off values of blood eosinophil count >265cell/ µL, plasma Periostin concentration >15.747 ng/ml and FEV1% < 40.5% were associated with post treatment FEV1 response. Conclusions: COPD patients with poor lung functions regarding FEV1/FVC ratio, FEV1 actual value (L) and FEV1% of predicted as well as high blood eosinophil count and high plasma periostin concentration are predicted to have FEV1 response with fixed dose ICS/LABA combination treatment.