Longitudinal Assessment of Lung Function in Children With Sickle Cell Disease
Alan Lunt, Emily McGhee, Karl Sylvester, Gerrard F. Rafferty, Moira Dick, David Rees, Sue Height, Swee Lay Thein, Anne Greenough
Published in the journal Pediatric Pulmonology, December 2015
Sickle Cell Disease (SCD) is amongst the most prevalent genetic conditions worldwide. Only being inherited if both one’s parents carry a ‘faulty’ gene in their DNA, SCD affects the Haemoglobin molecules that carry Oxygen in the blood, changing the shape of the red blood cells into so-called crescent shaped ‘sickles’. Despite its commonness, with over 300,000 babies being born with SCD worldwide every year, a clear and consistent picture of how SCD affects the lungs of children with SCD had not yet been researched. This study aimed to research the lung function of children affected by the disorder over time, observing how this changed in early and later childhood, and how this was affected by episodes of ACS (Acute Chest Syndrome) in early childhood, when the sickle-shaped red blood cells can block blood vessels and lead to various different injuries.
Two groups of children were tested. The first, who were slightly younger on average, were
measured twice for their lung function over an average of 2 years, while the second group were measured twice over approximately 10 years. A number of methods were used to test each person’s lung function, including ‘spirometry’ in which the quantity of air one can force out the lungs is measured, among other values like lung capacity. These measurements were then compared to a ‘control’ group of healthy children without SCD at a similar age, to give a normal level of lung function to compare against the SCD patients’.
In both groups of children with SCD, a reduction in lung function over time was seen when compared to the groups of children without SCD. However, the lung function of those in the first, younger, group decreased at a faster rate.
The results suggest that the fastest period of deterioration in lung function takes place in early childhood. Indeed, having an episode of ACS in young childhood was the only factor found that increased the likelihood of worse overall lung function later on. This could explain the faster decline of the younger group, as ACS is more common in younger children. This would seem to conclude that a focus should be placed on preventing ACS in young children as a strategy to improve the general lung function later on of those with SCD.
This summary was produced by David Launer, Year 12 student from JFS School Harrow, as part of our departmental educational outreach programme.