Study of transcranial Doppler ultrasound and endothelin-1 in children with sickle cell anemia: a single-center study

To assess the impact of our transcranial Doppler (TCD) screening program on the incidence of a first stroke in children with sickle cell anemia and to study the role of elevated serum endothelin-1 (an inflammatory mediator) in these children. Background: stroke is a major complication of sickle cell disease (SCD), even in very young children. About 11% of children with homozygous sickle cell anemia (SS) develop stroke by the end of the second decade of life. The underlying etiology in most cases is an ischemic stroke caused by large-vessel stenosis or occlusion. Transcranial Doppler (TCD) recommended as a routine screening test to identify children at high risk of developing a stroke, measures flow velocities within large intracranial arteries. TCD should be routinely performed in children between 2 and 16 years as this age group is at the highest risk of sickle cerebral vasculopathy. We carried out a prospective case-control study which included 2 groups: a patient group consisted of 30 children with sickle cell anemia and sickle thalassemia and a group of 30 healthy children of matched age and sex. Each group included 11 males (36.5%) and 19 females (63.5%); the age range was 2 to 17 years. Both groups underwent a thorough clinical examination and laboratory tests (CBC, liver and renal function, serum ferritin and endothelin-1). Additionally, TCD was performed in all children included in the patient group. According to the results of TCD, time-averaged mean of the maximum velocity (TAMMX) was < 170 cm/s (normal), 170–200 cm/s (conditional), ≥ 200 cm/s (high risk) in 20 (66.7%), 4 (13.3%) 6 (20%) patients, respectively. The level of endothelin-1 was significantly higher in the patients (57.1 ± 91.3) than in the controls (21.9 ± 14.8). Hemoglobin concentration was significantly lower in the patient group than in the control group, but the levels of reticulocytes, WBCs and serum ferritin were significantly higher in the patients than in the healthy controls. Serum Endotheline-1 level was higher in patients with sickle cell anemia than control group.