The following is a summary of “Cerebral Hemodynamic Responses to Disease-Modifying and Curative Sickle Cell Disease Therapies,” published in the December 2024 issue of Neurology by Aumann et al.
Sickle cell disease (SCD) is a genetic disorder that results in the production of abnormal hemoglobin (Hb)-S, causing hemolytic anemia and an increased risk of stroke. Common treatments include hydroxyurea, transfusions, and hematopoietic stem cell transplantation (HSCT).
Researchers conducted a prospective study to evaluate how changes in Hb levels associated with therapies in SCD affect brain health biomarkers.
They assessed adults with and without SCD using 3T magnetic resonance imaging (MRI) at 2-time points, before and after a blood transfusion or HSCT, or at 2-time points without introducing a new hemoglobin-altering therapy (hydroxyurea). They measured cerebral blood flow (CBF) and cerebral venous blood relaxation rate using arterial spin labeling MRI and T2 relaxation under spin tagging MRI, respectively. Data were analyzed using a Wilcoxon signed-rank test and regression analysis (P<0.05).
The results showed that adults with SCD receiving hydroxyurea (n = 10) did not experience changes in Hb (8.6 ± 1.2 g/dL to 9.0 ± 1.8 g/dL), CBF, or venous relaxation rate (all P>0.05). In individuals receiving blood transfusions (n = 19), Hb increased from 8.2 ± 1.4 g/dL to 9.3 ± 1.3 g/dL (P<0.001), and CBF decreased by 14.2 mL/100 g/min (P<0.001). For individuals receiving HSCT (n = 14), Hb increased from 8.9 ± 1.9 g/dL to 12.9 ± 2.7 g/dL (P<0.001), CBF decreased from 68.16 ± 20.24 to 47.43 ± 12.59 mL/100 g/min (P<0.001), and venous relaxation rate increased (P=0.004). Across all individuals, a 1 g/dL increase in Hb was associated with a 5.02 mL/100 g/min decrease in CBF.
They concluded that blood transfusions and HSCT improved cerebral hemodynamics compared to hydroxyurea therapy, offering a framework for assessing brain health in individuals with SCD undergoing new treatments.
Source: neurology.org/doi/10.1212/WNL.0000000000210191
