Asthma/obstructive pulmonary disease overlap: update on definition, biomarkers, and therapeutics

Current insights on clinical efficacy of roflumilast for treatment of COPD, asthma and ACOS

Phosphodiesterase-4 inhibitors (PDE4) are of great interest for the treatment of airway inflammatory diseases due to its broad anti-inflammatory effects. Roflumilast is a selective PDE4 inhibitor that inhibits pulmonary and systemic inflammation and rallies symptoms in airway diseases. Asthma and COPD are common chronic airway inflammatory diseases having incompletely illustrious pathophysiology and clinical manifestations. Recently, the condition called Asthma- COPD Overlap (ACO) has been evolved having the overlapping symptoms of both diseases. The newly discovered PDE4 inhibitor, roflumilast has exposed its potential in the treatment of Asthma, COPD and ACOS. Its mechanism of action in airway inflammatory diseases are said to be exerts by elevating intracellular cAMP and shows its anti-inflammatory action. Roflumilast, a promising therapeutic approach in inflammatory airway diseases, has many significant outcomes. In this review, we have provided various promising clinical evidences of roflumilast in COPD and asthma. However, there is no published clinical evidence to date for the role of roflumilast in ACOS. Nevertheless, there are therapeutic mechanisms that provide a reference for clinical application for ACOS.

Serum periostin and TNF-α levels in patients with obstructive sleep apnea-hypopnea syndrome

PURPOSE

Obstructive sleep apnea-hypopnea syndrome (OSAHS) may cause pulmonary diseases, and periostin plays an important role on the development of pulmonary diseases. In addition, periostin and pro-inflammatory cytokine TNF-α can regulate each other in vivo. This study aimed to observe the changes of serum periostin and TNF-α levels in patients with OSAHS compared with healthy volunteers and to investigate their correlation.

METHODS

A convenience sample of 67 patients with OSAHS in our hospital from December 2018 to December 2019 was selected and categorized into mild, moderate, and severe groups according to apnea-hypopnea index by polysomnography. In addition, 21 healthy volunteers were selected as the control group. Serum levels of periostin and TNF-α were determined by enzyme-linked immunosorbent assay (ELISA). Results were analyzed using the SPSS software.

RESULTS

Both serum periostin and TNF-α levels in all the three OSAHS groups were higher than those of the control group and increased with severity of OSAHS. The severe group had significantly higher serum periostin and TNF-α levels than the mild and moderate groups (p < 0.05). For patients with OSAHS, serum periostin and TNF-α levels positively correlated with the apnea-hypopnea index (AHI) (p < 0.01) and negatively correlated with the lowest saturation oxygen (LSaO₂) and mean saturation oxygen (MSaO₂) (both p < 0.01). In addition, there was a positive correlation between serum periostin and TNF-α levels in patients with OSAHS (p < 0.001).

CONCLUSIONS

Serum periostin and TNF-α levels were significantly increased in patients with OSAHS and may serve as a potential biomarker for severity of OSAHS. These findings suggest that it may be fruitful to study the role of periostin and TNF-α in OSAHS-induced pulmonary diseases.

Between life and death: Epithelial cells in lung pathologies

Recent lineage tracing strategies, single-cell RNA sequencing approaches and high-resolution imaging identified remarkable heterogeneity of lung epithelial cells thus leaving open a question as to their specific functions in lung health and disease. Understanding the molecular mechanisms controlling lung epithelial cell morphogenesis and differentiation as well as communication with other cell types and extracellular matrix provides a basis for improving the outcome for patients with respiratory diseases. Although, the substantial progress has been made towards achieving this goal, we are still far away from being able to train/instruct lung epithelial cells in order to facilitate lung repair and regeneration. The special issue of the Cellular Signaling entitled "Between life and death: epithelial cells in lung pathologies" represents a blend of research articles and reviews, in which structural and functional diversities of lung epithelial cells in health and disease are discussed.