Logan T F, Virji M A, Gooding W E, Bontempo F A, Ernstoff M S, Kirkwood J M
Department of Medicine, University of Pittsburgh, Pa.
J Natl Cancer Inst. 1992 Dec 2;84(23):1802-10. doi: 10.1093/jnci/84.23.1802.
We noted the presence of plasma fibrin degradation products in patients treated with recombinant human tumor necrosis factor (TNF) in a phase I trial.
To further define this observation, we investigated the effects of TNF on the fibrinolytic system in patients entered in the same trial.
In the 14 patients studied, fibrinolytic parameters were measured by analyzing blood samples for tissue plasminogen activator and inhibitor at 0, 1, 2, 4, 6, and 18-24 hours after initiation of TNF treatment. We used a chromogenic substrate method to determine activity of plasminogen activator and its inhibitor and an enzyme-linked immunosorbent assay (ELISA) to determine levels of antigen (tissue-type plasminogen activator). Molecular weight was determined by zymographic assay.
TNF treatment was associated with tissue-type plasminogen activator induction within 1 hour of TNF initiation. The plasminogen activator produced was consistent with tissue-type plasminogen activator derived from endothelium as evidenced by molecular weight analysis and ELISA. Moreover, induction of plasminogen activator inhibitor occurred following the release of tissue-type plasminogen activator, and our data suggest a dose-response effect for TNF. At high doses (i.e., 200 and 240 micrograms/m2), there was a more rapid and prolonged release of plasminogen activator inhibitor, which had an inverse relationship with the level of antigenic tissue-type plasminogen activator. Zymographic analysis showed urokinase-type plasminogen activator activity in 13 of 14 patients. In three patients, simultaneous measurements of white blood cells and tissue-type plasminogen activator revealed a temporal association between the TNF-associated rapid granulocytopenia at 30 minutes after TNF initiation and release of tissue-type plasminogen activator antigen.
The results suggest a positive association between TNF and rapid induction of plasminogen activator activity that is consistent with an endothelial product. It is possible that, at high doses, TNF may interact directly with vascular endothelium, leading to rapid and prolonged production of plasminogen activator inhibitor. There was a dose-response effect between TNF and release of tissue-type plasminogen activator. The release of tissue-type plasminogen activator was preceded by granulocytopenia, which may indicate an association between a proposed TNF-induced granulocyte-endothelial interaction in vivo and release of tissue-type plasminogen activator.
These findings demonstrating the effects of TNF on the fibrinolytic system can be analyzed further in experimental systems to determine the implications for use of this agent as a biological response modifier in cancer therapy.
在一项I期试验中，我们注意到接受重组人肿瘤坏死因子（TNF）治疗的患者体内存在血浆纤维蛋白降解产物。
为进一步明确这一观察结果，我们对参与同一试验的患者中TNF对纤维蛋白溶解系统的影响进行了研究。
在研究的14例患者中，于开始TNF治疗后的0、1、2、4、6以及18 - 24小时采集血样，通过分析血样中的组织纤溶酶原激活物和抑制剂来测定纤维蛋白溶解参数。我们采用发色底物法测定纤溶酶原激活物及其抑制剂的活性，并用酶联免疫吸附测定法（ELISA）测定抗原（组织型纤溶酶原激活物）水平。通过酶谱分析法测定分子量。
TNF治疗与开始TNF治疗后1小时内组织型纤溶酶原激活物的诱导产生有关。经分子量分析和ELISA证实，所产生的纤溶酶原激活物与源自内皮细胞的组织型纤溶酶原激活物一致。此外，组织型纤溶酶原激活物释放后出现纤溶酶原激活物抑制剂的诱导产生，且我们的数据表明TNF存在剂量反应效应。在高剂量（即200和240微克/平方米）时，纤溶酶原激活物抑制剂的释放更为迅速且持续时间更长，其与抗原性组织型纤溶酶原激活物水平呈负相关。酶谱分析显示14例患者中有13例存在尿激酶型纤溶酶原激活物活性。在3例患者中，同时测量白细胞和组织型纤溶酶原激活物发现，TNF开始治疗后30分钟时与TNF相关的快速粒细胞减少症和组织型纤溶酶原激活物抗原的释放之间存在时间关联。
结果表明TNF与纤溶酶原激活物活性的快速诱导之间存在正相关，这与一种内皮细胞产物一致。在高剂量时，TNF可能直接与血管内皮相互作用，导致纤溶酶原激活物抑制剂快速且持续产生。TNF与组织型纤溶酶原激活物的释放之间存在剂量反应效应。组织型纤溶酶原激活物的释放之前有粒细胞减少症，这可能表明在体内推测的TNF诱导的粒细胞 - 内皮细胞相互作用与组织型纤溶酶原激活物的释放之间存在关联。
这些表明TNF对纤维蛋白溶解系统影响的发现可在实验系统中进一步分析，以确定该药物作为癌症治疗中的生物反应调节剂的应用意义。
