Maruyama M, Kamiguti A S, Cardoso J L, Sano-Martins I S, Chudzinski A M, Santoro M L, Morena P, Tomy S C, Antonio L C, Mihara H
Department of Physiology, Miyazaki Medical College, Japan.
Thromb Haemost. 1990 Jun 28;63(3):449-53.
The blood coagulation and the fibrinolytic systems of nine patients envenomed by Bothrops jararaca in São Paulo (Brazil) were studied. Five of the accidents were caused by young snakes (less than 50 cm). On admission, four patients had non-clotting and three partially-clotting blood. Fibrinogen levels were decreased due to the thrombin-like activity of the venom as expected. Consequent secondary activation of the fibrinolytic system was evident from the low levels of alpha-2-antiplasmin and the high titres of fibrin(ogen) degradation products. High titres of cross-linked fibrin fragment D (D-dimer) in seven patients together with decreased platelet counts and/or factor V, and/or factor VIII in some, suggests intrinsic thrombin formation as these factors are not consumed in the defibrinogenation induced by venom thrombin-like fractions such as Ancrod and Batroxobin. However, normal or increased levels of antithrombin III in all and normal levels of factor II in eight patients do not support this interpretation. The existence of variable concentrations of other proteins in the venom of B. jararaca such as botrocetin and thrombocytin isolated from B. jararaca and B. atrox or crotalocytin from Crotalus horridus venom should be considered. Such proteins are known to activate factors V, VIII, XIII, and platelets without affecting prothrombin (factor II) and antithrombin III. Slower recovery of the haemostatic disturbances after antivenom administration to patients bitten by young snakes suggests a more severe coagulopathy in such accidents. This is supported by clinical observations.
对巴西圣保罗9名被巴西矛头蝮蛇咬伤中毒患者的凝血和纤溶系统进行了研究。其中5例咬伤是由幼蛇（小于50厘米）造成的。入院时，4例患者血液不凝，3例部分凝血。正如预期的那样，由于毒液的类凝血酶活性，纤维蛋白原水平降低。从低水平的α-2-抗纤溶酶和高滴度的纤维蛋白（原）降解产物可以明显看出纤溶系统随之发生的继发性激活。7例患者的交联纤维蛋白片段D（D-二聚体）滴度高，同时部分患者血小板计数和/或因子V和/或因子VIII降低，提示内源性凝血酶形成，因为在诸如安克洛酶和巴曲酶等毒液类凝血酶组分诱导的去纤维蛋白原作用中，这些因子不会被消耗。然而，所有患者抗凝血酶III水平正常或升高，8例患者因子II水平正常，这并不支持这种解释。应考虑巴西矛头蝮蛇毒液中存在其他可变浓度的蛋白质，如从巴西矛头蝮蛇和矛头蝮蛇中分离出的博曲酶和血小板促凝蛋白，或从猪鼻蝰蛇毒液中分离出的响尾蛇促凝蛋白。已知这些蛋白质可激活因子V、VIII、XIII和血小板，而不影响凝血酶原（因子II）和抗凝血酶III。给被幼蛇咬伤的患者注射抗蛇毒血清后，止血障碍的恢复较慢，这表明此类咬伤事故中的凝血病更为严重。临床观察结果支持这一点。
