Sickle cell/β-thalassemia: Comparison of Sβ0 and Sβ+ Brazilian patients followed at a single institution

Abstract

Objectives: In sickle cell/β-thalassemia, mutations in the corresponding β-globin genes are responsible for complex pathological events resulting in diverse clinical complications. The objective of this study was to provide an overview of the clinical and laboratory characteristics of patients with the syndrome, and of the degree of severity of clinical manifestations resulting from the β-thalassemia mutation. Methods: A retrospective chart review was performed on 46 patients with sickle cell/β-thalassemia (31 Sβ° and 15 Sβ+), evaluating hematological parameters and end organ damage. Statistical analyzes were carried out in order to highlight differences between the two groups according to the nature of the thalassemia mutation. Results: As expected, patients with the Sβ0 phenotype had a higher degree of hematological involvement in comparison to Sβ+ patients; with lower hemoglobin levels, and signs of more intense chronic hemolysis. However, Sβ+ patients were more prone to the occurrence of acute chest syndrome. The impact of the thalassemia mutation upon total body and bone composition was also evident, as Sβ0 patients presented lower body mass index (BMI) and bone mineral density. The degree of bone damage correlated to lower BMI and hemoglobin levels, as well as plaquetosis, monocytosis and elevated lactate dehydrogenase, possibly reflecting the effects of hemolysis and inflammation upon bone metabolism and body constitution. Conclusions: This study identified significant differences among sickle cell/β-thalassemia patients according to the beta mutation involvement, pointing to an important predictor of disease severity.