ASSOCIATION BETWEEN THE HOMOZYGOUS STATUS FOR THE 807T ALLELE OF ITGA2 AND RETINAL ARTERY OCCLUSION

Abstract number: P-W-482

Regina¹ S., Arsène² S., Le Lez² M., Delahousse¹ B., Gruel¹ Y.

¹¹Haematology-Haemostasis, Trousseau Hospital ²²Ophthalmology, Bretonneau Hospital, TOURS, France

How-to-cite Regina S, Arsène S, Le Lez M, Delahousse B, Gruel Y. ASSOCIATION BETWEEN THE HOMOZYGOUS STATUS FOR THE 807T ALLELE OF ITGA2 AND RETINAL ARTERY OCCLUSION. J Thromb Haemost 2007; 5 Supplement 2: P-W-482

Abstract

Introduction: Central Retinal Artery Occlusion (CRAO) and Anterior Ischaemic Optic Neuropathy (AION) are ophthalmologic emergencies often associated with severe visual loss. A cause i.e. vascular emboli, hypertension or Horton disease, is not always found and increased platelet activation might be involved in some patients. In addition, the 807T allele of ITGA2 coding for integrin a2 has been associated with a prothrombotic platelet phenotype. The aim of this study was therefore to investigate if this allele is associated with an increased risk of CRAO.

Methods: Seventy Caucasian patients with CRAO (n=53) or AION (n=17), median age = 65.5 years (28-92) (29 women and 41 men), were studied. Patients were matched in age and gender with normal subjects (n=14) or ophthalmologic patients without any history of retinal occlusion (n=56). All investigations for conventional causes or risk factors of CRAO were performed in every patient. The 807 C/T polymorphism of ITGA2 was studied by RFLP. In addition, 2 other polymorphisms in GPVI (T13254C) and GPIb alpha (Kozak -5T/C) genes, which are also coding for proteins involved in platelet adhesion, were analysed in all patients and controls.

Results: 28.5% of patients (20/70) and 7.5% (5/70) of controls were homozygous for the 807T allele of ITGA2 (OR 5.15; 95% CI 1.8-14, p=0.009). This higher frequency of 807TT patients was found both in patients with RCAO (20%, p=0.02) and AION (35%, p=0.007). Interestingly, the 807T allele of ITGA2 was more frequent in patients without emboli or atherosclerosis (16/34, 47%) than in those with (4/36, 11%; OR=7 CI 95% 2-24, p=0.0008). Finally,no significant difference in allele frequency was found between patients and controls regarding GPVI and GPIb alpha Kozak polymorphisms.

Conclusions: The homozygous status for the 807T allele of ITGA2 is associated with an increased risk of retinal artery occlusion particularly in patients without atherosclerosis.

To cite this abstract use the following format:

Journal of Thrombosis and Haemostasis 2007; Volume 5, Supplement 2: abstract number

Session Details

Date:	01/08/2007
Time:	00:00-00:00
Session name:	XXIst ISTH Congress
Subject:
Location:	Oxford, UK
Presentation type:
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