Lung transplant and obliterative bronchiolitis (OB)

Lung transplantation is now an established treatment for end stage lung diseases, regardless of cause. Around 200 lung transplants are carried out each year in the UK. This involves major surgery and is then followed by intensive and life-long immune-suppression, to prevent the patient’s body from rejecting the new lungs. Long term survival is limited mainly by the development of chronic rejection. This process is called obliterative bronchiolitis (OB) and is characterised by narrowing and blockage of small airways in the lungs.

Detecting Obliterative Bronchiolitis (OB)

One of the major challenges in dealing with OB is that we lack the tools to identify disease early. Standard lung function tests, like spirometry, only detect disease that is already established, and other detection methods involve either radiation or invasive lung biopsy, which make them unsuitable for repeated routine use.

An alternative method of lung assessment is the multiple breath washout test, which measures how efficiently gases mix in the lungs during normal relaxed breathing. The lung clearance index (LCI) calculated from this test has been shown in other diseases to be highly sensitive to the sorts of changes in the lungs that are similar to those seen with OB. We and others have measured LCI after lung transplant and have shown that it differs in those already diagnosed with OB. We believe that measuring LCI routinely in clinic will allow us to detect changes in the lungs earlier than current standard tests.

The Electra study

The Electra study is open to all lung transplant patients at the Manchester Lung Transplant Centre, regardless of reason for transplant, and will run for 4 years. This is an observational study, meaning that we will not be directly changing patients’ treatments. However, we will be using a change in LCI at routine clinic review to direct more frequent follow-up or more detailed lung assessments (CT, bronchoscopy). Early identification of OB in this way will allow us to alter immune-suppression in order to prevent disease progression, ultimately improving survival after lung transplant.

In addition to LCI, we will also use cutting-edge magnetic resonance imaging (MRI) technologies to investigate how OB develops. These MRI tests can be used to image gas mixing in the lungs, and do not use radiation. This will allow us to match up the changes seen in simple tests like LCI, which might be deployed in all transplant clinics, with more detailed and specialised 3-dimensional assessments of lung disease. Finally, we will perform new laboratory tests of lung rejection and infection on samples taken routinely from transplant patients. This will allow us to match the changes we measure in LCI or MRI to the disease processes in the airways.

Find out more about Electra

Involving patients

This study has been developed with the assistance of lung transplant patients and is supported, and co-funded, by the Manchester Lung Transplant charity. Lung transplant patients have helped develop study documents and sit on the study steering committee. Study updates and results will be communicated to patients and carers via newsletters, and we will write to all participants at the study completion to outline our findings.