Cerebrovascular Reserve and White Matter Disease in Patients With Chronic Anemia

About the study

This is primarily an observational trial in patients with chronic anemia syndromes (sickle cell disease and thalassemia) and control subjects. The key purpose is to understand how brain blood flow reserve (the ability of the brain to increase its flow in response to stress) is altered in patients with chronic anemia. Since this parameter may depend on anemia severity, we will perform the MRI monitoring prior to and following clinically indicated transfusions in a subset of patients. Most patients will already be prescribed hydroxyurea as part of their standard of care. Since hydroxyurea could impact brain blood flow, there is also a small pilot study (20 patients, nonrandomized, open label) where MRI imaging will be performed prior to and following administration of hydroxyurea up to maximum tolerated dose. The study will enroll 90 adult subjects with transfusion independent sickle cell disease (70 SS, 10 SC, 10 Sβ0) and 60 patients with transfusion-dependent sickle cell disease. It will also include 10 transfusion independent thalassemia patients and 20 transfusion dependent thalassemia patients as well as 40 control subjects recruited from first degree relatives of the sickle cell disease population. All eligible subjects will be asked to provide informed consent before participating in the study.

Study point of contact

Obdulio Carreras
Mike Gawad


1 United States site


> 7 Years

Study type






Gender Description

for healthy controls we will try to match gender to those that have been enrolled under the anemia cohort

participation requirements

Diagnosis of sickle cell disease (genotype SS, SC, or SB0), thalassemia (transfusion dependent or transfusion independent), or normal control subject that are ≥18yrs, ethnicity, and sex matched to the sickle cell disease population.
Ability to tolerate a one hour MRI examination.
Age equal to or greater than 7 years old for Anemia groups.
Agreeable to use an approved method of contraception for the entire duration of hydroxyurea usage if accepted onto the hydroxyurea substudy (male or female of childbearing potential)

participation restrictions

Hospitalization within one month
Contraindication to acetazolamide use (seizures)
Severe claustrophobia.
Pregnancy or nursing (a negative HCG (pregnancy) test must be obtained prior to MRI)
As a result of medical review, physical examination or screening investigations, the Principal Investigator (PI) considers the subject unfit for the study
No fixed address
In control subjects, chronic hepatitis, diabetes, hypertension, coronary artery disease, cognitively impaired or developmental delay


  • Los Angeles, California, United States, CHLA, 90027 [Recruiting]
Last updated 2022-07-13