Evaluation serum levels of YKL-40, Periostin, and some inflammatory cytokines together with IL-37, a new anti-inflammatory cytokine, in patients with stable and exacerbated asthma

Abstract

Introduction: As asthma has a wide range of inflammatory pathways, the researchers were focused on the markers that may be associated with exacerbation and stability in asthma.

Objective: Our aim is to investigate the serum levels of some inflammatory markers and cytokines in stable and exacerbated asthmatic patients.

Methods: The study included in 59 non-smoker asthma patient (Exacerbated=25, Stable=34) and 30 healthy volunteers. The serum level of periostin, YKL-40, IL-4, IL-5, IL-37, and TNF-α were detected by enzyme-linked immunosorbent assay.

Results: Except for IL-37, the periostin, YKL-40, IL-4, IL-5, and TNF-α level in asthmatic patients were significantly higher than those of healthy control. In the exacerbated group, the periostin, YKL-40, IL-5, and TNF-α level were significantly higher than stable asthma and healthy control groups. The serum levels of IL-4 in exacerbated and stable asthma groups were significantly higher than healthy control group. There was a significant difference between IL4 levels, in stable asthma and healthy control groups. In exacerbated asthma group, IL-37 level was significantly lower than stable and healthy control groups. The highest area under the ROC curve (AUC) was found for IL-4. While there was a significant negative correlation between these parameters and FEV1, there was a positive correlation between IL-37 and FEV1, but not significant.

Conclusions: This study showed that increased serum periostin, YKL-40, IL-5, IL-4, and TNF-α and decreased serum IL-37 were associated with exacerbation showing uncontrolled asthma.

Keywords: Asthma; IL-37; YKL-40; cytokines; exacerbation; periostin.