The COVID HOME study research protocol: Prospective cohort study of non-hospitalised COVID-19 patients.

Background: Guidelines on COVID-19 management are developed as we learn from this pandemic. However, most research has been done on hospitalised patients and the impact of the disease on non-hospitalised and their role in transmission are not yet well understood. The COVID HOME study conducts research among COVID-19 patients and their family members who were not hospitalised during acute disease, to guide patient care and inform public health guidelines for infection prevention and control in the community and household.

A pro-inflammatory role for the Frizzled-8 receptor in chronic bronchitis.

Rationale: We have previously shown increased expression of the Frizzled-8 receptor of the Wingless/integrase-1 (WNT) signalling pathway in COPD. Here, we investigated if the Frizzled-8 receptor has a functional role in airway inflammation associated with chronic bronchitis.

Methods: Acute cigarette-smoke-induced airway inflammation was studied in wild-type and Frizzled-8-deficient mice.

Novel genes for airway wall thickness identified with combined genome-wide association and expression analyses.

Rationale: Airway wall thickness (AWT) is affected by both environmental and genetic factors and is strongly associated with airflow limitation in smaller airways.

Objectives: To investigate the genetic component of AWT.

Methods: AWT was measured on low-dose computed tomography scans in male heavy smokers participating in a lung cancer screening study (n = 2,640).

Chronic respiratory symptoms associated with airway wall thickening measured by thin-slice low-dose CT.

Objective: In lung cancer screening, the prevalence of chronic respiratory symptoms is high among heavy smokers. The purpose of this study was to compare CT-derived airway wall measurements between male smokers with and those without chronic respiratory symptoms.

Materials And Methods: Fifty male heavy smokers with chronic respiratory symptoms (cough, excessive mucus secretion, dyspnea, and wheezing) and 50 without any respiratory symptom were randomly selected from the Dutch-Belgian Randomized Lung Cancer Screening Trial.

Dissecting the genetics of chronic mucus hypersecretion in smokers with and without COPD.

Smoking is a notorious risk factor for chronic mucus hypersecretion (CMH). CMH frequently occurs in chronic obstructive pulmonary disease (COPD). The question arises whether the same single-nucleotide polymorphisms (SNPs) are related to CMH in smokers with and without COPD.

Susceptibility to chronic mucus hypersecretion, a genome wide association study.

Background: Chronic mucus hypersecretion (CMH) is associated with an increased frequency of respiratory infections, excess lung function decline, and increased hospitalisation and mortality rates in the general population. It is associated with smoking, but it is unknown why only a minority of smokers develops CMH. A plausible explanation for this phenomenon is a predisposing genetic constitution.

Risk factors for chronic mucus hypersecretion in individuals with and without COPD: influence of smoking and job exposure on CMH.

Background: Chronic mucus hypersecretion (CMH) is highly prevalent in smokers and associated with an accelerated lung function decline and chronic obstructive pulmonary disease (COPD). Several risk factors contribute to CMH and to COPD. It is, however, unknown if risk factors for CMH are similar in persons with and without COPD.

Low-dose CT measurements of airway dimensions and emphysema associated with airflow limitation in heavy smokers: a cross sectional study.

Background: Increased airway wall thickness (AWT) and parenchymal lung destruction both contribute to airflow limitation. Advances in computed tomography (CT) post-processing imaging allow to quantify these features. The aim of this Dutch population study is to assess the relationships between AWT, lung function, emphysema and respiratory symptoms.

CT-quantified emphysema in male heavy smokers: association with lung function decline.

Background: Emphysema and small airway disease both contribute to chronic obstructive pulmonary disease (COPD), a disease characterised by accelerated decline in lung function. The association between the extent of emphysema in male current and former smokers and lung function decline was investigated.

Methods: Current and former heavy smokers participating in a lung cancer screening trial were recruited to the study and all underwent CT.