title: Erythrocyte deformability and aggregation in homozygous sickle cell disease.
abstract: Rheological properties of homozygous sickle cell anaemia (SCA) show marked heterogeneity, which may be explained in part by the concomitance of alpha genotypes or beta haplotypes, along with hydroxurea (HU) treatment. To further clarify this issue, in 11 homozygous patients with SCA in the steady state and in 16 healthy controls, we analysed erythrocyte deformability (ED) in a Rheodyn SSD by means of the Elongation Index (EI) at 12, 30 and 60 Pa, and erythrocyte aggregation at stasis (EA0) and at 3 sec-1 (EA1) in a Myrenne aggregometer along with fibrinogen, biochemical and haematological parameters. When compared with controls, homozygous (SS) patients showed a lower EI at all the shear stresses tested (p < 0.01) and higher EA0 (p < 0.014), but not higher EA1 (p = 0.076). Fibrinogen did not show statistical differences (p = 0.642). In the Spearman's correlation IE60 correlated inversely with Hb S (p < 0.05) and directly with MCV, MCH and Hb F levels (p < 0.01). EA0 correlated inversely with MCV, MCH, Hb F (p < 0.01) and directly with Hb S (p < 0.05). HU treatment improved EI and EA0, but not EA1. This paradoxical behaviour of HU on erythrocyte aggregation merits further research to be clarified.
authors.affiliation: Haemorheology and Haemostasis Unit, Service of Clinical Pathology, La Fe University Hospital, Valencia, Spain.
authors.forename: Amparo
authors.initials: A
authors.lastname: Vayá
authors.affiliation: Haemorheology and Haemostasis Unit, Service of Clinical Pathology, La Fe University Hospital, Valencia, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Collado
authors.affiliation: Pediatry Service, La Fe University Hospital, Valencia, Spain.
authors.forename: Maria Angeles
authors.initials: MA
authors.lastname: Dasí
authors.affiliation: Haematology Service, La Fe University Hospital, Valencia, Spain.
authors.forename: Maria Luz
authors.initials: ML
authors.lastname: Pérez
authors.affiliation: Haemorheology and Haemostasis Unit, Service of Clinical Pathology, La Fe University Hospital, Valencia, Spain.
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Hernandez
authors.affiliation: Molecular Biology Unit, Service of Clinical Pathology, La Fe University Hospital, Valencia, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Barragán
mesh_terms: D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000188:drug therapy; D000986:Antisickling Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004903:Erythrocyte Aggregation / Q000502:physiology*; D004907:Erythrocyte Deformability / Q000502:physiology*; D004912:Erythrocytes / Q000473:pathology*; D005260:Female; D018056:Hemorheology; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use; D008297:Male; D055815:Young Adult
chemical_list: D000986:Antisickling Agents; D006918:Hydroxyurea
keywords: Sickle cell disease; erythrocyte aggregation; erythrocyte deformability; hydroxyurea treatment