It has beenshown that hyperhomocysteinemia can inhibit the binding of tPA withits receptor annexin II, thereby reducing plasmin synthesis.54-56 In line with these findings, in a recent meta-analysis and meta-regressionof case-control studies, it has been reported that in Alzheimer patients,there is an approximate one-third increase in blood homocysteine,independently of disease severity.57 This evidence concerns the gene PLAT and hyperhomocysteinemia.