Limits...
Blood thixotropy in patients with sickle cell anaemia: role of haematocrit and red blood cell rheological properties.

Vent-Schmidt J, Waltz X, Romana M, Hardy-Dessources MD, Lemonne N, Billaud M, Etienne-Julan M, Connes P - PLoS ONE (2014)

Bottom Line: Blood thixotropy was determined by measuring blood viscosity with a capillary viscometer using a "loop" protocol: the shear rate started at 1 s-1 and increased progressively to 922 s-1 and then re-decreased to the initial shear rate.RBC deformability was determined by ektacytometry and RBC aggregation properties by laser backscatter versus time.While RBC deformability and aggregation were lower in SS than in AA, the strength of RBC aggregates was higher in the former population.

View Article: PubMed Central - PubMed

Affiliation: Inserm UMR 1134, Hôpital Ricou, CHU de Pointe-à-Pitre, 97157, Pointe-à-Pitre, Guadeloupe, France.

ABSTRACT
We compared the blood thixotropic/shear-thinning properties and the red blood cells' (RBC) rheological properties between a group of patients with sickle cell anaemia (SS) and healthy individuals (AA). Blood thixotropy was determined by measuring blood viscosity with a capillary viscometer using a "loop" protocol: the shear rate started at 1 s-1 and increased progressively to 922 s-1 and then re-decreased to the initial shear rate. Measurements were performed at native haematocrit for the two groups and at 25% and 40% haematocrit for the AA and SS individuals, respectively. RBC deformability was determined by ektacytometry and RBC aggregation properties by laser backscatter versus time. AA at native haematocrit had higher blood thixotropic index than SS at native haematocrit and AA at 25% haematocrit. At 40% haematocrit, SS had higher blood thixotropic index than AA. While RBC deformability and aggregation were lower in SS than in AA, the strength of RBC aggregates was higher in the former population. Our results showed that 1) anaemia is the main modulator of blood thixtropy and 2) the low RBC deformability and high RBC aggregates strength cause higher blood thixotropy in SS patients than in AA individuals at 40% haematocrit, which could impact blood flow in certain vascular compartments.

Show MeSH

Related in: MedlinePlus

A–C: Blood viscosity hysteresis loop (3A), differences between the two blood viscosity curves of the loop obtained on Fig. 3A (3B) and blood thixotropic index in patients with sickle cell anaemia (SS) and healthy individuals (AA) at 40% haematocrit. Significant difference: *p<0.05.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4263608&req=5

pone-0114412-g003: A–C: Blood viscosity hysteresis loop (3A), differences between the two blood viscosity curves of the loop obtained on Fig. 3A (3B) and blood thixotropic index in patients with sickle cell anaemia (SS) and healthy individuals (AA) at 40% haematocrit. Significant difference: *p<0.05.

Mentions: Figs. 3A and 3B depict the mean hysteresis loop and the difference in blood viscosity between the two curves for SS and AA at 40% Hct, respectively. Blood viscosity at 40% Hct was higher in SS than in AA (p<0.001). We observed higher thixotropic index in SS than in AA (Fig. 3C, p<0.05).


Blood thixotropy in patients with sickle cell anaemia: role of haematocrit and red blood cell rheological properties.

Vent-Schmidt J, Waltz X, Romana M, Hardy-Dessources MD, Lemonne N, Billaud M, Etienne-Julan M, Connes P - PLoS ONE (2014)

A–C: Blood viscosity hysteresis loop (3A), differences between the two blood viscosity curves of the loop obtained on Fig. 3A (3B) and blood thixotropic index in patients with sickle cell anaemia (SS) and healthy individuals (AA) at 40% haematocrit. Significant difference: *p<0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263608&req=5

pone-0114412-g003: A–C: Blood viscosity hysteresis loop (3A), differences between the two blood viscosity curves of the loop obtained on Fig. 3A (3B) and blood thixotropic index in patients with sickle cell anaemia (SS) and healthy individuals (AA) at 40% haematocrit. Significant difference: *p<0.05.
Mentions: Figs. 3A and 3B depict the mean hysteresis loop and the difference in blood viscosity between the two curves for SS and AA at 40% Hct, respectively. Blood viscosity at 40% Hct was higher in SS than in AA (p<0.001). We observed higher thixotropic index in SS than in AA (Fig. 3C, p<0.05).

Bottom Line: Blood thixotropy was determined by measuring blood viscosity with a capillary viscometer using a "loop" protocol: the shear rate started at 1 s-1 and increased progressively to 922 s-1 and then re-decreased to the initial shear rate.RBC deformability was determined by ektacytometry and RBC aggregation properties by laser backscatter versus time.While RBC deformability and aggregation were lower in SS than in AA, the strength of RBC aggregates was higher in the former population.

View Article: PubMed Central - PubMed

Affiliation: Inserm UMR 1134, Hôpital Ricou, CHU de Pointe-à-Pitre, 97157, Pointe-à-Pitre, Guadeloupe, France.

ABSTRACT
We compared the blood thixotropic/shear-thinning properties and the red blood cells' (RBC) rheological properties between a group of patients with sickle cell anaemia (SS) and healthy individuals (AA). Blood thixotropy was determined by measuring blood viscosity with a capillary viscometer using a "loop" protocol: the shear rate started at 1 s-1 and increased progressively to 922 s-1 and then re-decreased to the initial shear rate. Measurements were performed at native haematocrit for the two groups and at 25% and 40% haematocrit for the AA and SS individuals, respectively. RBC deformability was determined by ektacytometry and RBC aggregation properties by laser backscatter versus time. AA at native haematocrit had higher blood thixotropic index than SS at native haematocrit and AA at 25% haematocrit. At 40% haematocrit, SS had higher blood thixotropic index than AA. While RBC deformability and aggregation were lower in SS than in AA, the strength of RBC aggregates was higher in the former population. Our results showed that 1) anaemia is the main modulator of blood thixtropy and 2) the low RBC deformability and high RBC aggregates strength cause higher blood thixotropy in SS patients than in AA individuals at 40% haematocrit, which could impact blood flow in certain vascular compartments.

Show MeSH
Related in: MedlinePlus