eNOS Gene Affects Blood Viscosity and Red Cell Deformability: Role of eNOS T-786C, G894T and 4a/4b Polymorphisms

Abstract number: P1773

Mannini¹ L, Fatini¹ C, Sticchi¹ E, Lapini¹ I, Bigi¹ P, Leporini² E, Pagnini² P, Gensini¹ GF, Prisco¹ D, Abbate¹ R

¹¹Department of Medical and Surgical Critical Care, Thrombosis Centre, University of Florence; Azienda Ospedaliero-Universitaria Careggi, Florence, Italy ¹¹Department of Medical and Surgical Critical Care, Thrombosis Centre, University of Florence; Azienda Ospedaliero-Universitaria Careggi, Florence, Italy ²²Department of Oto-Neuro-Ophtalmology, University of Florence, Italy

Plasma viscosity and erythrocyte aggregation play a key role in maintaining and regulating microcirculation. In vitro and in vivo studies suggested a role for nitric oxide (NO) in modulating flow-mediated vasodilatation and red blood cell deformability. Impaired NO availability due to mutations in eNOS gene might contribute to altered haemorheological state. Aim of this study was to investigate the role of eNOS T-786C, G894T and 4a/4b polymorphisms in influencing haemorheological state. We studied 80 Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) patients and 80 healthy subjects. From the multivariate analysis a significant association between eNOS 894T rare variant and ISSHL (OR 894TT + GT = 2.08, P= 0.03) was found. A higher percentage of altered erythrocyte filtration test (EFT) both in patients and in controls carrying the eNOS rare variants was found in comparison to subjects carrying the wild-type.

Apart from the disease, eNOS T-786C and G894T polymorphisms independently affected the EFT (OR -786CC + TC = 2.81, P= 0.01 and OR 894TT+GT = 2.5, P= 0.02, respectively), in particular in subjects in whom the contemporary presence of the two rare alleles was observed (OR -786CC + TC and 894TT+GT combined genotype = 6.9, P < 0.0001). Our study documented that eNOS gene affects the red blood cell deformability, so possibly contributing to ISSHL, which may represent a suitable model of microcirculatory disorder.