Study links high level of iron in lungs to increased asthma severity

The build-up of iron in the lung cells and tissues is associated with worst asthma symptoms and lower lung function, suggests a new study.

Washington D.C. [USA], Mar 18 : The build-up of iron in the lung cells and tissues is associated with worst asthma symptoms and lower lung function, suggests a new study.

The first of its kind to study the relationship between iron build-up in the lung cells and tissues, collecting data from asthma patient samples and mouse models, was published in the European Respiratory Journal [1].

Experimental models also showed that iron build-up in the lungs triggers immune system responses that are typical in asthma and lead to worsening of the disease. This includes effects like increased mucus secretion and scarring of the lungs, which result in a narrowing of the airways and making breathing difficult.

"Our organs and tissues need iron to support oxygen flow and normal enzyme activity, but infections in the body also need iron to thrive. Because of this, our immune system has ways of hiding iron minerals within cells where infections cannot access the iron. This can result in a build-up of iron in the cells and tissues of nearby organs," said Jay Horvat, Associate Professor of Immunology and Microbiology at the University of Newcastle and Hunter Medical Research Institute, Australia, the lead author of the study

"There is evidence that irregular iron absorption and abnormal iron levels are linked to lung disease. We know that both high and low iron levels are reported in asthma, but it is not clear whether iron build-up in the lungs contributes to disease development. We sought to build on this by investigating the link between iron and asthma, to better understand whether increased or decreased iron levels in the lung cells make the disease worse."

The researchers conducted multiple tests to asses iron levels in the airway cell samples and found that iron levels outside of the lung cells were lower in asthma patients compared with healthy people; iron levels were also significantly lower in severe asthmatics compared with mild-to-moderate asthmatics.

Taken together, the results show that lower iron levels outside of cells and higher iron levels within cells were both associated with lower lung function and worsen asthma.

Next, the researchers carried out lab tests using two different mouse models to investigate the effects of increasing lung cell iron levels on asthma severity.

The analyses showed that increasing the lung cell iron levels caused inflammatory cell responses such as increased mucus secretion and scarring in the airways, which the researchers say leads to worsening of asthma.

Professor Horvat explained: "In humans, mucous secretion and lung scarring narrows the airways, causing airflow obstruction and breathing difficulties. These symptoms are common in asthma and other chronic lung diseases, and our data shows that increasing iron in the lung cells and tissues led to an increase in these effects."

Further research needs to confirm this finding and investigate this process, which could possibly lead to new therapies. It is important to note that the research does not suggest high iron levels in the lungs is because of diet.

( With inputs from ANI )