A Study On Associations Of Apolipoprotein E Genotypes And Promoters Polymorphisms With The CVS And Rebleeding After Spontaneous SAH

Objective To investigate the influence of the APOE gene and promoters polymorphisms on cerebral vasospasm (CVS) and rebleeding of patients with spontaneous subarachnoid hemorrhage (SAH). Methods One hundred and eighty-five patients with spontaneous SAH were selected in this study. Venous Blood samples and clinical data of the patients were collected. The APOE polymorphisms of all patients were determined by PCR-RFLP, and the promoters'polymorphisms were determined in 101 patients. Associations of APOE genotypes and promoters polymorphisms with cerebral vasospasm and rebleeding after SAH were analysized byχ2 test, Uni- and multivariate logistic regression (SPSS verion 13.0).Results1. The relationship between APOE and CVS.The distributions of APOE and promoters genotypes and alleles matched Hardy-Weinberg Law. In 185 patients, 21 of 32 (65.7%) patients with ApoEε4 allels showed CVS, while only 56 (36.7%) out of 153 patients without APOEε4 showed it. Incidence rate of CVS in ApoEε4 (+) group was significantly higher than that in ApoEε4 (-) (P=0.022). Uni- and multivariate logistic regression analyses demonstrated that ApoEε4 allels was a risk factor of CVS incidence.In 101 patients whose promoter polymorphisms were determined, 42 of 87 patients (48.3%) with promoter -219T allels showed CVS, while 23 of 61 patients (37.7%) with -219G allels showed CVS. The Incidence of CVS in -219T group was significantly higher than that in -219G group (P=0.044). Uni- and multivariate logistic regression analyses also show that promoter -219T was a risk factor of CVS incidence.The 3-4 grade of Fisher scale was also a risk factor of CVS (P=0.041).2. The relationship between APOE and rebleeding.Though the ratio of rebleeding in either APOEε2 or APOEε24 carriers was higher than that of either non- APOEε2 or non- APOEε4 carriers repectively, no statistical significances were found (ε2 P=0.648,ε4 P=0.822). There was also no statistical difference in percentage of rebleeding between APOEε3 and non- APOEε3 carriers even though less cases of rebleeding were obversed in patients with APOEε3 (P=0.606).There were 13 patients had history of rebleeding in the 101 patients whose promoter polymorphisms were determined.χ2 test and logistic regression analyses showed insignificant differences in association of APOE promoter polymorphisms with rebleeding(P>0.05)Conclusions1. Our findings suggested that the patients with APOEε4,-219T promoter alleles and 3-4 grade of Fisher scale predispose to CVS after spontaneous SAH.2. The relationship of APOE and promoter polymorphisms with rebleeding after SAH is not verified and needs further study.