Hemorheological risk factors of acute chest syndrome and painful vaso-occlusive crisis in children with sickle cell disease

Abstract

BackgroundLittle is known about the effects of blood rheology on the occurrence of acute chest syndrome and painful vaso-occlusive crises in children with sickle cell anemia and hemoglobin SC disease. Design and MethodsTo address this issue, steady-state hemorheological profiles (blood viscosity, red blood cell deformability, aggregation properties) and hematologic parameters were assessed in 44 children with sickle cell anemia and 49 children with hemoglobin SC disease (8-16 years old) followed since birth. Clinical charts were retrospectively reviewed to determine prior acute chest syndrome or vaso-occlusive episodes, and rates of these complications were calculated. ResultsMultivariate analysis revealed that: 1) a higher steady-state blood viscosity was associated with a higher rate of vaso-occlusive crises in children with sickle cell anemia, but not in children with hemoglobin SC disease; 2) a higher steady-state red blood cell disaggregation threshold was associated with previous history of acute chest syndrome in children with hemoglobin SC disease and boys with sickle cell anemia. ConclusionsOur results indicate for the first time that the red blood cell aggregation properties may play a role in the pathophysiology of acute chest syndrome in children with hemoglobin SC disease and boys with sickle cell anemia. In addition, whereas greater blood viscosity is associated with a higher rate of vaso-occlusive crises in children with sickle cell anemia, no association was found in children with hemoglobin SC disease, underscoring differences in the etiology of vaso-occlusive crises between sickle cell anemia and hemoglobin SC disease.

Hematologic and hemorheological determinants of resting and exercise-induced hemoglobin oxygen desaturation in children with sickle cell disease

“…20,22,23,39 Therefore, SC and SS children were analyzed separately. Part of the results described here were previously included in a report on the initial SAPOTILLE cohort.…”

“…22 Serum lactate dehydrogenase and total bilirubin concentrations were determined by standard biochemical methods.…”

“…22 The rates of ACS and VOC were calculated for each child by dividing the total number of ACS or painful VOC episodes by the number of patient-years. 22,31 The study was conducted in accordance with the Declaration of Helsinki and was approved by the Regional Ethics Committee (CPP Sud/Ouest Outre Mer III, Bordeaux, France; registration number 2009-A00211-56). Children and their parents were informed of the purpose and procedures of the study, and gave written consent.…”

“…2,6,11 Sickle cell disease is characterized by severe hemorheological abnormalities that play a role in the pathophysiology of several acute and chronic complications. [16][17][18][19][20][21][22][23][24] Experimental work in non-SCD subjects and mathematical modeling strongly suggest that hemorheological impairment may contribute to hemoglobin oxygen desaturation at rest. 25 Hematocrit and red blood cell (RBC) deformability have been demonstrated to modulate pulmonary diffusing capacity.…”

The paradox of the serrated sickle erythrocyte: The importance of the red blood cell membrane topography

“…It turns out that these factors have the opposite effect. Patients (both adults and children) who have decreased cell deformability and increased number of ISC and dense cells have mild disease with respect to the VOC [5][6][7]. A subsequent study showed patients whose RBC deformability averaged 37% or less of control values and whose dense cells averaged 22% of total circulating cells had fewer VOCs, less mortality, higher incidence of leg ulcers, and lower incidence of urinary tract infection although their Hb F was relatively low [8].…”