title: Haemolysis and abnormal haemorheology in sickle cell anaemia.
abstract: Although pulmonary hypertension, leg ulcers, priapism, stroke and glomerulopathy in sickle cell anaemia (SCA) result from the adverse effects of chronic haemolysis on vascular function (haemolytic phenotype), osteonecrosis, acute chest syndrome and painful vaso-occlusive crises are caused by abnormal vascular cell adhesion and increased blood viscosity (viscosity-vaso-occlusion phenotype). However, this model with two sub-phenotypes does not take into account the haemorheological dimension. We tested the relationships between the biological parameters reflecting the haemolytic rate (haemolytic component) and red blood cell (RBC) rheological characteristics in 97 adults with SCA. No significant difference in the proportion of patients with low or high haemolytic component in the low and high blood viscosity groups was observed. The RBC elongation index (i.e. deformability) was negatively correlated with the haemolytic component. The RBC aggregates strength (i.e. RBC aggregates robustness) was negatively correlated with RBC elongation index. Sickle RBCs with high density had lower elongation index and higher aggregates strength. In conclusion, (i) the 'haemolytic' phenotype is characterized by decreased RBC deformability and increased RBC aggregates strength and (ii) the viscosity-vaso-occlusive phenotype is characterized by increased RBC deformability but not always by increased blood viscosity. α-thalassaemia modulates the haemorheological properties but other factors seem to be involved.
authors.affiliation: UMR Inserm 1134, Université des Antilles et de la Guyane, Pointe-à-Pitre, Guadeloupe, France; Institut Universitaire de France, Paris, France; Laboratory of Excellence GR-Ex (The red cell: from genesis to death), PRES Sorbonne Paris Cité, Paris, France; Laboratoire ACTES (EA 3596), Département de Physiologie, Université des Antilles et de la Guyane, Pointe-à-Pitre, Guadeloupe, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Connes
authors.forename: Yann
authors.initials: Y
authors.lastname: Lamarre
authors.forename: Xavier
authors.initials: X
authors.lastname: Waltz
authors.forename: Samir K
authors.initials: SK
authors.lastname: Ballas
authors.forename: Nathalie
authors.initials: N
authors.lastname: Lemonne
authors.forename: Maryse
authors.initials: M
authors.lastname: Etienne-Julan
authors.forename: Olivier
authors.initials: O
authors.lastname: Hue
authors.forename: Marie-Dominique
authors.initials: MD
authors.lastname: Hardy-Dessources
authors.forename: Marc
authors.initials: M
authors.lastname: Romana
mesh_terms: D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000150:complications; D001809:Blood Viscosity; D004909:Erythrocyte Indices; D004913:Erythrocytes, Abnormal / Q000473:pathology; D006454:Hemoglobins / Q000032:analysis; D006461:Hemolysis; D018056:Hemorheology; D006801:Humans; D017085:alpha-Thalassemia / Q000097:blood / Q000150:complications
chemical_list: D006454:Hemoglobins
keywords: haemolysis; haemorheology; sickle cell disease