Background: Periostin, an extracellular matrix protein, is involved in inflammatory processes of the lung. To date, most studies have focused on periostin in asthma patients, its role in chronic obstructive pulmonary disease (COPD) is less clear and no information has been reported on blood levels of periostin in COPD patients in the context of exacerbation rates. As such, this exploratory study aimed to investigate whether periostin is helpful to distinguish between COPD patients with frequent and infrequent exacerbations.
Methods: We performed an examination of patients with COPD participating in a COPD cohort study in Switzerland. Periostin levels were determined in serum samples by using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. Patients underwent evaluation of clinical symptoms including exacerbation rate (exacerbation defined by requiring oral corticosteroids and/or antibiotics) and lung function. In a subgroup of patients an annual follow-up was available that was considered in an additional analysis.
Results: Twenty six patients (global initiative of obstructive lung disease (GOLD) stage 1 none, 31% stage 2, 38% stage 3, 31% stage 4) were included in the analysis. The mean±standard deviation (SD) age of the patients was 63±5.9 years, 16 were males, 24 were smokers or exsmokers. The median (quartiles) post-bronchodilator FEV1% predicted was 36(27/57). There was no significant difference in periostin levels between patients with frequent and infrequent exacerbations. The follow-up data revealed no evidence that periostin is helpful in distinguishing frequent from infrequent exacerbators.
Conclusion: Our analysis performed in a small group of carefully matched COPD patients demonstrates that there is no significant relationship between exacerbation rate and periostin levels in blood.