Spirometry Patterns in Adult Sickle Cell Disease: A Retrospective Observational Study.

BACKGROUND: Patients with sickle cell disease (SCD) are at an increased risk of pulmonary complications, including acute chest syndrome, which can lead to significant morbidity and mortality. OBJECTIVE: To determine the impact of SCD on pulmonary functions using spirometry and to identify an association between the level of hemoglobin S (Hgb S) and spirometry values. METHODS: This retrospective study enrolled adult patients with SCD who had undergone spirometry testing at a university hospital in Saudi Arabia between February 2020 to January 2023. Spirometry parameters included forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and their ratio. Abnormal spirometry was subcategorized into obstructive and restrictive patterns. Spirometry was performed according to the American Thoracic Society/European Respiratory Society guidelines. RESULTS: The study included 68 patients with SCD (female: 67.7%). A total of 28 (41.2%) patients had abnormal spirometry, of whom 85.7% had restrictive patterns. No statistically significant correlation was found between Hgb S levels and FVC or FEV1. Baseline characteristics including age, sex, previous medical history of pneumonia or ACS, use of HU, white blood cells, hemoglobin levels and hemoglobin electrophoresis, were not statistically different between those with normal and abnormal spirometry. However, SCD patients with abnormal spirometry had higher platelet counts (P = 0.03). CONCLUSION: This study found that higher Hgb S levels were not associated with abnormal spirometry in patients with sickle cell disease. The predominant abnormal spirometry pattern was restrictive, and higher platelet counts is a potential predictor of an abnormal spirometry in patients with sickle cell disease.