Blood eosinophil count predicting later life airways disease

Airways disease, which includes asthma and chronic obstructive pulmonary disease (COPD), is the name for diseases of the lung which can cause cough, breathlessness and flare-ups which can be very serious, including causing death. COPD and late-onset asthma (which if poorly controlled can cause lung damage) are often only diagnosed late in life when the lung may already have been damaged. We are trying to find a way to identify those people who are more likely to develop airways disease in future, and to try to find treatments that may prevent or delay symptoms.

Eosinophils are a type of white blood cell, and are often tested by GPs as part of the ‘full blood count’. Previous research has showed that higher levels of eosinophils in the blood are linked with deteriorating lung function over time, and that higher blood eosinophils can identify those who will respond best to a steroid (tablet or inhaler). But no studies so far have looked at whether higher blood eosinophils in earlier life can predict whether someone will develop airways disease in later life.

We are planning to use a large database of information recorded in patients’ notes as part of their GP care called the Clinical Practice Research Datalink (CPRD). This information is anonymous, and includes diagnoses, medication prescribed and blood results. We will group patients into those who are diagnosed with late-onset airways disease, and those who are not, and then compare their blood eosinophil levels during their earlier life to see if there is a difference between groups. We will also look at how the blood eosinophils change over the years prior to the diagnosis.

If we find that blood eosinophils are higher in people who will develop airways disease in future, we will then plan further research to develop tools to predict future airways disease, to investigate whether any treatments can help prevent them developing it in the future (e.g. steroid inhalers, or giving up smoking) and whether we can test patients for early disease using sensitive tests of airway function. This would benefit patients because if we can look for (screen) patients with this blood marker before they develop any symptoms, and start treatments earlier, it could prevent them from developing the disease and reduce lung damage and symptoms.

A patient expert with lived experience of asthma is contributing to this application and will be involved in the study, to ensure that the research is relevant to patients, sense checking the findings, and particularly will be involved in developing future research work in this area. Findings of this study will be published in medical journals and communicated to patient groups through respiratory disease charities and social media.

Amount Awarded: £16,350