Frequency and distribution of asymptomatic brain lesions in patients with β-thalassemia intermedia

Abstract

We aimed to determine the frequency of asymptomatic brain lesions in a group of patients with β-thalassemia intermedia (β-TI) and to evaluate correlation of asymptomatic brain lesions with splenectomy, thrombocytosis, blood transfusions, and clinical parameters. Ninety five neurologically intact patients with β-TI were randomly enrolled in this cross-sectional study. Diffusion-weighted imaging brain MRI was performed in every patient to detect cerebral white matter lesions (WML). We found an overall frequency of 15 (15.8%) for WMLs, 14 (23.7%) in splenectomized, and 1 (2.8%) in nonsplenectomized patients. The presence of WML was significantly associated with splenectomy (P = 0.008) and thrombocytosis (P = 0.009). However, after adjustment for splenectomy, thrombocytosis was not significantly associated with the presence of WML (P > 0.05). The number of patients with regular blood transfusions and normal MRI was not significantly higher compared to those with abnormal findings (52.5% vs. 26.7%; P = 0.092). In untransfused patients, hydroxyurea (HU) administration was associated with a lower incidence of WML (P < 0.001). Although in univariate analysis either splenectomy or thrombocytosis showed significant correlation with the presence of single or multiple WMLs, thrombocytosis by itself did not significantly contribute in developing asymptomatic brain lesions. The lack of significant correlation between lesions and regular blood transfusions could be related to the treatment with HU in untransfused patients, which increased fetal hemoglobin levels and improved the morphology and the pathological indices of the red blood cells. Larger prospective studies are suggested for the accurate evaluation of the correlation of these factors with developing asymptomatic brain lesions.