The lungs are part of the respiratory system which help a person breath. They provide oxygen to blood when we breathe in that then gets pumped out to the body. When we breathe out, wasteful gases are removed from the blood. Sickle cell disease can affect the lungs by damaging the tissues of the lung making it more difficult for gas exchange and oxygenation of blood to occur.

How do we measure lung health?

• Pulse oximetry: An electronic device that can be attached to a finger in order to measure how much oxygen is being carried in red blood cells. This is a very simple, fast test that can be performed at the doctor’s office.


• Pulmonary function tests: A group of tests used to assess how the lungs are working. Spirometry is a specific type of pulmonary function test that measures how much air you can breathe in and out of your lungs. The forced expiratory volume (FEV1) is a measurement that is done as part of spirometry.

How does sickle cell disease affect the lungs?

Over time, patients with sickle cell disease can develop obstructive and/or restrictive lung disease. Obstructive lung disease is caused by blockage of the airways. Restrictive lung disease occurs when the lungs are not able to fully expand. Pulmonary function tests can help diagnose and differentiate different types of lung disease. About one third of adults with sickle cell disease can have low FEV1, and this has been shown to be a predicter of earlier death. Furthermore, restrictive lung disease can be associated with an increased risk of death in patients with sickle cell disease (1).

Lung disease can start at a young age and is related to the number of episodes of acute chest syndrome that a person has. About 10% of children and adolescents can have a low FEV1 (2).

The COALESCE study will help us study how curative therapy affects lung function. We will be collecting data on lung function from participants before and after curative therapy.

References

1. Kassim AA, Payne AB, Rodeghier M, Macklin EA, Strunk RC, DeBaun MR. Low forced expiratory volume is associated with earlier death in sickle cell anemia. Blood. Sep 24 2015;126(13):1544-50. https://doi.org/10.1182/blood-2015-05-644435


2. Chaturvedi S, Ghafuri DL, Jordan N, Kassim A, Rodeghier M, DeBaun MR. Clustering of end-organ disease and earlier mortality in adults with sickle cell disease: A retrospective-prospective cohort study. Am J Hematol. Sep 2018;93(9):1153-1160. https://doi.org/10.1002/ajh.25202