Effects of hydroxyurea on blood rheology in sickle cell anemia: A two-years follow-up study

Abstract

The aim of the present study was to test the effects of hydroxyurea (HU) therapy on clinical, hematological and hemorheological parameters in adult patients with sickle cell anemia (SCA). Hematological and hemorheological parameters were measured in 28 SCA patients before HU therapy (i.e., baseline) and at 6, 12 and 24 months of treatment. RBC deformability was determined by ektacytometry at 30 Pa. RBC aggregation properties were investigated by light-backscatter method. Blood viscosity was measured at 225 s-1 by a cone-plate viscometer. The rates of vaso-occlusive crises and acute chest syndrome were lower at 1 and 2 years of HU therapy compared to baseline. The proportion of patients with leg ulcers tended to decrease after 2 years of treatment. Hemoglobin oxygen saturation improved with HU therapy. HU therapy induced a decrease of platelet and white blood cell counts and a rise in fetal hemoglobin level and mean cell volume. While hemoglobin concentrations increased under HU, blood viscosity remained unchanged all along the study. RBC deformability increased over baseline values at 6 months of HU therapy and continued to rise until the end of the follow-up period. In conclusion, the improvement in RBC deformability probably compensates the increase of hemoglobin on blood viscosity and participates to the improvement of the clinical status of patients.

Annual stroke incidence in Nigerian children with sickle cell disease and elevated TCD velocities treated with hydroxyurea

“…The increase in hematocrit was associated with improved physical activity in the children. Lemonne et al . reported increases in fetal hemoglobin levels and the hematocrit and a decrease in platelet and WBC counts in adult patients treated with HU.…”

“…The increase in hematocrit was associated with improved physical activity in the children. Lemonne et al 31 reported increases in fetal hemoglobin levels and the hematocrit and a decrease in platelet and WBC counts in adult patients treated with HU. HU has been shown to raise hematocrit levels, decrease platelet and white cell count levels, reduce frequency of hospitalizations, pain encounters, and emergency department visits in children with SCD.…”

Eryptosis and hemorheological responses to maximal exercise in athletes: Comparison between running and cycling

“…13 Blood viscosity is also strongly affected by the RBC rheological properties, with a rise in RBC deformability and a decrease in RBC aggregation resulting in a decrease in blood viscosity. 3,28,29 Indeed, the increase in RBC deformability and the lack of change in RBC aggregation observed during the running test have probably limited the rise in blood viscosity caused by the change in hematocrit.…”

Rheological properties of sickle erythrocytes in patients with sickle‐cell anemia: The effect of hydroxyurea, fetal hemoglobin, and α‐thalassemia

“…Improvement in RBC rheology after treatment with HU was described previously in two patients treated with HU 1 and more recently in an open-label, uncontrolled study from a single institution involving about 30 patients. 6,7 In this study, we investigated the modulating role of HbF and α-thalassemia on RBC deformability in patients with and without HU, with some patients enrolled in MSH.…”