Tran Huyen A, Eikelboom John W
Australian Centre for Blood Disease, 6th Floor, Burnet Tower, 89 Commercial Road, Melbourne, Victoria 3004, Australia.
Curr Treat Options Cardiovasc Med. 2007 Jun;9(3):191-7. doi: 10.1007/s11936-007-0012-7.
Protein Z (PZ) is a vitamin K-dependent plasma glycoprotein that acts as a cofactor for PZ-dependent protease inhibitor to inhibit coagulation factor X(a). Studies in mice suggest that that decreased blood PZ levels lead to reduced inhibition of blood coagulation, thereby predisposing to thrombosis; however, clinical studies in humans have yielded conflicting results. Among patients with stroke, some epidemiologic studies have reported that reduced PZ levels increase the risk of stroke, whereas others have reported no association between PZ levels and stroke, or that elevated PZ levels increase stroke risk. Polymorphisms involving the gene for PZ can influence the PZ concentration and some polymorphisms (eg, intron G79A AA allele) may be protective against stroke, particularly among younger individuals. Although the association between PZ levels and stroke appears to be stronger in younger patients and in patients who do not have conventional vascular risk factors, it remains unclear whether the link between PZ levels and stroke is confounded or causal or whether blood levels of PZ are altered as a consequence of the acute stroke event.
蛋白Z（PZ）是一种维生素K依赖的血浆糖蛋白，作为依赖蛋白Z的蛋白酶抑制剂的辅因子，抑制凝血因子X（a）。对小鼠的研究表明，血液中PZ水平降低会导致凝血抑制作用减弱，从而易发生血栓形成；然而，针对人类的临床研究结果却相互矛盾。在中风患者中，一些流行病学研究报告称，PZ水平降低会增加中风风险，而另一些研究则报告PZ水平与中风之间无关联，或者PZ水平升高会增加中风风险。涉及PZ基因的多态性可影响PZ浓度，某些多态性（如内含子G79A AA等位基因）可能对中风具有保护作用，尤其是在较年轻个体中。尽管PZ水平与中风之间的关联在较年轻患者以及无传统血管危险因素的患者中似乎更强，但PZ水平与中风之间的联系是混杂因素导致的还是因果关系，或者PZ血液水平是否因急性中风事件而改变，目前仍不清楚。
