Heterogeneity of respiratory disease in children and young adults with sickle cell disease
Alan Lunt, Lucy Mortimer, David Rees, Sue Height, Swee Lay Thein and Anne Greenough
Published in the journal Thorax, November 2017
The purpose of this study was to look at the different types of breathing problems which affect people who have sickle cell disease (SCD). This is important because although it is known that many people with SCD also suffer from lung disease, not every person with SCD is affected in the same way, so it is important to try to categorise the different presentations with the goal of improving future treatment of SCD.
In order to achieve this goal, the study first measured several physical characteristics in each of 114 people with SCD. These included the volume and speed at which they could breathe in and out, the capacity of their lungs, how easy it was for air to travel through their airways, the amount of blood circulating in the lungs, and how well their blood carries oxygen.
The researchers then used a technique called cluster analysis to find three groups of individuals who shared particular characteristics. The first group had more blood in the vessels supplying the lungs, and respiratory disease caused by a combination of narrowed airways and a restricted lung expansion (which makes it harder to breathe). The second group was composed of older patients who had respiratory disease caused by restrictions on how much the lungs can expand, poorer uptake of oxygen in the lungs, and only mild anaemia. The third group were younger patients with lung disease caused by narrowed airways, more evidence of damage to red blood cells., and were most likely to benefit from a reliever asthma inhaler. The people in the third group had been admitted to hospital for their SCD more often.
Further analysis showed that people could be classified into one of the three groups based on results from two simple breathing tests and a blood test, meaning that identifying which group people with SCD fall into could be done relatively easily in future studies or in the clinic.
The results of this study show that respiratory disease experienced by people with SCD can be categorised into three groups, which may help to make future management of this condition easier by delivering more individual treatments.
This summary was produced by Gideon Bernstein, Year 12 student from JFS School, Harrow, as part of our departmental educational outreach programme.