Alpha-thalassaemia promotes frequent vaso-occlusive crises in children with sickle cell anaemia through haemorheological changes

Céline Renoux (1) , Philippe Connes (1) , Elie Nader (1) , Sarah Skinner (1) , Camille Faes (1) , Marie Petras (2) , Yves Bertrand (3) , Nathalie Garnier , Daniela Cuzzubbo , Lydia Divialle-Doumdo (2) , Kamila Kebaili (4) , Cécile Renard , Alexandra Gauthier (1) , Maryse Etienne-Julan (5) , Giovanna Cannas (6, 1) , Cyril Martin (1) , Marie-Dominique Hardy-Dessources (7) , Vincent Pialoux (1) , Marc Romana (8) , Philippe Joly (1)

1 LIBM - Laboratoire Interuniversitaire de Biologie de la Motricité
2 Unité Transversale de la Drépanocytose
3 UMR AGAP - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales
4 Service d'hématologie : Immuno-Hématologie pédiatrique et transplantation de moelle osseuse
5 Unité Transversale de la Drépanocytose
6 Hôpital Edouard Herriot [CHU - HCL]
7 DSIMB Réunion - Dynamique des Structures et Interactions des Macromolécules Biologiques - Pôle de La Réunion
8 Protéines de la membrane érythrocytaire et homologues non-érythroides

BACKGROUND: Sickle cell anaemia (SCA) is a severe hereditary haemoglobinopathy characterised by haemorheological abnormalities, which play a role in the occurrence of several acute and chronic clinical complications. While βS -haplotypes and alpha-thalassaemia modulate SCA clinical severity, their effects on blood rheology have been incompletely described. The aim of this study was to test the effects of these genetic modifiers on the haemorheological properties and clinical complication of children with SCA. PROCEDURE: Steady-state haemorheological profile, biological parameters, βS -haplotypes, alpha-globin status, vaso-occlusive crisis (VOC) and acute chest syndrome frequencies were analysed in 128 children (aged 5 to 18 years) with SCA. RESULTS: Patients with alpha-thalassaemia showed increased red blood cell (RBC) deformability and aggregation compared to those without. Median VOC rate was higher in patients with homozygous alpha-thalassaemia compared to those with a normal alpha genotype. Conversely, the haemorheological profile and clinical complications were not influenced by the βS -haplotypes in our study. CONCLUSION: Our results demonstrate that alpha-thalassaemia is associated with higher risk for VOC events in children with SCA, which may be due in part to its effects on RBC deformability and aggregation.

Mots clés: sickle cell disease; haemorheology; alpha-thalassaemia; βS-haplotypes; vaso-occlusive crisis; sickle cell disease; haemorheology; βS-haplotypes; vaso-occlusive crisis

Domaines: Génétique humaine

Céline Renoux, Philippe Connes, Elie Nader, Sarah Skinner, Camille Faes, et al.. Alpha-thalassaemia promotes frequent vaso-occlusive crises in children with sickle cell anaemia through haemorheological changes. Pediatric Blood and Cancer, 2017, 64 (8), ⟨10.1002/pbc.26455⟩. ⟨hal-01668317⟩