Children with sickle cell disease at greater risk of lung diseases

Washington, May 19 : Children with sickle cell disease (SCD) are at a greater risk of developing lung diseases following a decline in lung function, according to a new study.

For the study, the researchers analysed 1,357 lung function results between January 1989 and January 2005 on from 413 children with SCD during routine sickle cell clinical visits. Lung volume measurements were also included for 1,129 records.

"The restrictive pattern of decline is supportive of early injury or inflammation resulting in progressive changes in lung volumes across age," said Dr Joanna MacLean, lead researcher, of the department of respiratory medicine at Children's Hospital at Westmead in Australia.

"We expected that children with sickle cell disease would show greater loss of lung function than other children, but this had never been quantified, nor was the pattern of decline clear," MacLean added.

The findings showed a significant decline in lung function with a decline in the percent-predicted values for all spirometry measures except FEV1/FVC ratio, a marker of airway obstruction.

The pattern of decline of lung volume confirmed a restrictive pattern with an average loss of 2 percent per year of total lung capacity.

"Most studies of lung function in children with sickle cell disease are either cross-sectional or have limited longitudinal follow-up," MacLean said.

"The strength of our study is that data was collected from a large number of children with sickle cell disease across childhood," she added.

They also found that of children with SCD, hemoglobin-beta genotype SS was associated with an increased risk of loss of lung function across childhood. This pattern of decline in lung function may simply reflect a greater risk of lung injury in this group.

"Our findings confirm that lung disease in SCD begins in childhood. Using statistical modelling, we are able to predict the rate of decline of lung function. These results can be used as a baseline against which results from intervention studies can be compared," MacLean said.

"The results of this project emphasize the need for further investigation into the pathophysiology and treatment of lung disease in children with sickle cell disease," she added.

The study was presented at the American Thoracic Society's 2008 International Conference in Toronto on Sunday.

ANI