Southampton researchers have given new insight into the causes of bronchiectasis.
The new research has revealed that an inherited condition is often underdiagnosed as a cause of the lung disease. Primary ciliary dyskinesia (PCD) is a rare disorder that gets worse over time.
Researchers hope the study will encourage physicians and GPs to 'Think PCD'. This could help patients get the treatment they need more efficiently.
The new study was driven by experts from the University of Southampton, University Hospital Southampton and the NIHR Southampton Biomedical Research Centre.
What is bronchiectasis?
Bronchiectasis is a long-term lung condition where the airways of the lungs become widened. It affects more than 200,000 people in the UK.
Common symptoms include a persistent cough, shortness of breath and recurring infections. It can lead to progressive chronic lung damage.
Improved social conditions and accessible health care mean infective causes of bronchiectasis are uncommon in the UK. There are many more genetic causes. These include cystic fibrosis, primary immunodeficiency and PCD.
An underdiagnosed cause
The study, published in the European Respiratory Journal, used data from the UK 100,000 Genomes Project. It recruited people with bronchiectasis but without clinical suspicion of PCD to find out if the condition is underdiagnosed.
The researchers used whole genome sequencing. They identified variants responsible for causing the disease in motile ciliopathy genes in 12 per cent of patients (17/142). This confirmed a diagnosis of PCD.
One person within the study had genetic variants in a gene that is important for the function of non-motile cilia, CEP164.
The Southampton team also demonstrated that variants in CEP164 affect motile (moving) cilia found in the lungs. This was the cause of bronchiectasis in the primary study, adding to the genes known to cause PCD-like syndromes. The separate paper was published in Clinical Genetics.
Jane Lucas, Professor of Paediatric Respiratory Medicine, said: “There are currently four national PCD centres in the UK – in Southampton, Leicester, Leeds and Royal Brompton London. But without a diagnosis of PCD, patients do not have access to their NHS specialist multidisciplinary teams to optimally manage their disease.
She added: “Our research highlights the need for pulmonary physicians and GPs to investigate the underlying cause of bronchiectasis. In the case of PCD, the history typically includes a daily wet cough from infancy, neonatal respiratory distress, rhinitis, glue ear and rhinosinusitis.
“Half of patients also have situs inversus, a rare genetic condition in which the organs in your chest and abdomen are positioned in a mirror image of normal human anatomy.
“With more genetic testing we will be able to identify bronchiectasis in more patients and ensure appropriate treatment is given to those who need it.”
Katie Dexter, from PCD Support UK, was diagnosed with PCD in her late teens.
She commented: “This study confirms PCD Support UK’s concern that many with bronchiectasis have undiagnosed PCD. Without a diagnosis of PCD, individuals are likely to be excluded from accessing comprehensive specialised PCD care and risk experiencing poor long-term management of the condition.
“As a patient without heterotaxy, I did not receive a PCD diagnosis until my late teens. However, I was tested for cystic fibrosis (CF) around age 11. If CF was considered, then why not PCD? The answer is simple: my physicians were not aware of PCD.
“PCD Support UK are hopeful that this study will help raise awareness among physicians of the urgent need to 'think PCD' as a potential underlying cause of bronchiectasis.”
Image credit: Ciliated airway cells. Courtesy of Jane Lucas.