Getting a Head Start on Cystic Fibrosis

Lung clearance index detects early cystic fibrosis in children

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Cystic Fibrosis is a genetic disease and early detection can lead to better treatment and quality of life. A new study shows a non-invasive test to be effective in detecting early cystic fibrosis in children.

The lung clearance index (LCI) can help detect early cystic fibrosis in children according to a new study. The LCI was non-invasive and the results were reproducible.

By detecting cystic fibrosis early, doctors can begin treatment earlier leading to better quality of life.

"Ask your doctor about available cystic fibrosis tests for children."

The LCI study was led by Yvonne Belessis, M.B.B.S., M.P.H., Ph.D., respiratory staff specialist at the Sydney Children's Hospital. Using multiple breath washout (MBW) testing to determine LCI, the study involved 48 infants and young children with minor cystic fibrosis symptoms and 25 healthy children as a control. An additional test, bronchoalveolar lavage (BAL), was used for children with cystic fibrosis.

"We found that LCI is elevated early in children with CF, especially in the presence of airway inflammation and Pseudomonas aeruginosa," said Belessis.

"LCI may not only be a marker of early CF lung disease, but may be useful as an objective outcome measure in future studies of young children with CF."

The MBW is used to measure lung function. An inert gas is inhaled into the lungs and researchers then measure how long it takes for all of that gas to leave the lungs during normal breathing. The LCI is determined by the MBW score.

The BAL is a test that uses a bronchoscope, a camera, that is inserted into the lungs and is used to diagnose lung diseases such as cystic fibrosis.

The average LCI score for children with cystic fibrosis was 7.21 compared to a score of 6.45 of healthy children. The highest score that would still be considered normal was 7.41. Out of the 47 cystic fibrosis patients, 15 children had a higher-than-normal LCI score.

Using BAL, the researchers were able to determine airway infections in 15 children with cystic fibrosis. Out of the 15 children with airway infections, 7 had a Pseudomonas aeruginosa infection. P. aeruginosa can exacerbate cystic fibrosis symptoms including cough and reduced appetite.

An abnormal LCI score was linked to BAL detection of an airway infection.

Limitations to the study included a higher BAL threshold than normally used to detect airway infection.

Future studies can determine how effective LCI can be in detecting cystic fibrosis. Further studies can determine if LCI score can predict cystic fibrosis severity. Longer studies are also needed to account for any changes in airway infection or inflammation.

LCI can be a non-invasive way to detect lung disease in children. Early detection can go a long way in helping treat the disease and could be a useful tool for a genetic disease like cystic fibrosis.

No funding information was published. No author conflicts were reported.

This study was published in the January edition of American Journal of Respiratory and Critical Care Medicine.

Reviewed by: 
Review Date: 
January 31, 2012
Last Updated:
February 1, 2012