The Utility of Lung Clearance Index in Ethnic Groups and in Disease
Condition: Healthy Children; Bronchiectasis Adult; Lung Clearance Index
MeSH terms: Bronchiectasis
Study type: Interventional

Summary: 
      Introduction:

      Non-CF, non-PCD bronchiectasis in children is a chronic, suppurative lung disease diagnosed
      by high resolution computed tomography (HRCT) imaging of the lungs. Spirometry can be
      abnormal in bronchiectasis but has been shown to be insensitive to early disease in other
      related conditions such as cystic fibrosis. Lung clearance index (LCI) could have a role in
      assessment of the disease.

      Lung clearance index is calculated from multiple breath washout tests. There are limited data
      on the normative values expected using some devices, in a range of ages, and between ethnic
      groups.

      The investigators aim to establish normative values in children aged between 6 years and 12
      years, to investigate differences between ethnic groups, and to establish the relationship
      between lung clearance index and other measures of disease in children with bronchiectasis.

      Methods:

      Healthy children will be recruited from a range of settings and reviewed to ensure no
      previous lung disease. Children with bronchiectasis diagnosed on HRCT will be recruited from
      the outpatient service of Birmingham Children's Hospital.

      All participants will perform lung function tests including LCI and spirometry. Basic
      demographic data was collected.
    

Detailed description: 
      Rationale / Hypothesis:

      Hypothesis 1

      Having established normative ranges helps support interpretation of lung function testing
      which is key to their value as an investigation. With LCI, it is important to understand the
      difference that may be expected between children

      of different ethnic backgrounds (as demonstrated with other, non-LCI measures of lung
      function, where important differences between different ethnic groups has been found).

      LCI is calculated from an internally adjusted measure of an individual subject's lung volume,
      therefore potentially negating inherent differences in ethnic variation.

      Therefore we hypothesize that there are no differences in LCI in healthy children from
      differing ethnic backgrounds.

      Evidence supporting this hypothesis is not only of intellectual value, but it would also
      allow clinicians to confidently interpret a range of LCI readings using globally acquired
      normal values. Should the data not support the hypothesis, an important direction for future
      research would be established.

      Hypothesis 2

      LCI has been demonstrated to detect small differences in lung function and correlates well
      with CT imaging in some disease states. There is a paucity of data in its use in its lung
      disease outside of CF. Current availability of easy to use, repeatable and reliable devices
      allows LCI to be measured in the clinic setting (Downing et al. 2016).

      Understanding the relationship between CT changes and LCI in younger children with lung
      disease, would allow a non-invasive investigation (LCI) to be used to guide care and monitor
      treatment.

      In order to understand how LCI changes, we also intend to determine how LCI varies in
      children with Non-CF, Non-PCD Bronchiectasis over a prolonged period of time.

      The investigators hypothesize that in younger children with Non-CF, Non-PCD Bronchiectasis
      and evidence of milder disease on CT, LCI is a more sensitive disease marker than FEV1, and
      varies over time.
    

Intervention name(s): Lung Clearance Index
Intervention type(s): Diagnostic Test
Intervention description(s): Normative values in healthy children from ethnic backgrounds
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic