MicroRNAs as fibrosis markers in patients with hypersensitivity pneumonitis

Abstract

Hypersensitivity pneumonitis (HP) is a complex interstitial pulmonary syndrome. This clinical entity is characterized by sensitization to a specific antigen. Early detection of this antigen is associated with an increased likelihood of a favorable outcome. Increased mortality in hypersensitivity pneumonitis is associated with the development of lung fibrosis. At the same time, clinical interventions do not significantly improve the prognosis of the disease due to a lack of understanding the mechanisms underlying the development of this type of fibrosis. Using reliable biomarkers that objectively reflect biological processes in lung fibrosis may improve clinical decisionmaking. Various biomarkers are now beginning to play a critical role in diagnosing and treating a variety of human diseases. Unfortunately, hypersensitivity pneumonitis is an exception to this general trend. There is still a great deal of research to be done in this area in the search for diagnostic biomarkers. The aim of this study was to identify biomarkers of lung fibrosis development in patients with hypersensitivity pneumonitis. We used mature serum microRNAs, which may regulate inflammation and fibrosis, as such diagnostic markers. Patients with a diagnosis of hypersensitivity pneumonitis (with and without lung fibrosis) as well as healthy individuals without chronic diseases (control group) were included into the study. Clinical and laboratory parameters were assessed in all patients. The miScript miRNA PCR Array Kit (QIAGEN) was used for gene expression profiling of mature serum miRNAs. The data obtained were verified using real-time PCR. Our research has identified a number of mature microRNAs that are likely to be involved in lung fibrosis and inflammation (miR-22, miR-150 and miR-106b). Following an extended study, including monitoring of disease progression over time, the applied diagnostic kit may be used in clinical practice to determine disease activity and development of fibrosis formation in lung tissue in patients with different variants of hypersensitivity pneumonitis.