Antithrombin III prevents deleterious effects of remote ischemia-reperfusion injury on healing of colonic anastomoses

BACKGROUND: Antithrombin III is known as the most important natural inhibitor of thrombin activity and has been shown to attenuate local harmful effects of ischemia-reperfusion injury in many organs. In recent animal studies, delaying effect of remote organ ischemia-reperfusion injury on healing of intestinal anastomoses has been demonstrated. In this study, we investigated whether antithrombin III reduces deleterious systemic effects of ischemia-reperfusion injury on healing of colonic anastomoses in rats. METHODS: Anastomosis of the left colon was performed in 24 rats that were divided into three groups: sham operated control (group I, n = 8), 30 minutes of intestinal ischemia-reperfusion by superior mesenteric artery occlusion (group II, n = 8), antithrombin III treated group (250 U/kg before and after the ischemia-reperfusion, group III, n = 8). On postoperative day 6, all animals were sacrificed, and bursting pressure and tissue hydroxyproline content of the anastomoses were assessed and compared. RESULTS: On postoperative day 6 the mean bursting pressures were 149.6 +/- 4.8, 69.8 +/- 13.5, and 121.8 +/- 8.7 mm Hg for groups I, II, and III, respectively (P = 0.000). Mean tissue hydroxyproline concentration values were 389.5 +/- 29.6, 263.1 +/- 10.0, and 376.0 +/- 33.8 microg/mg for groups I, II, III respectively (P = 0.005). CONCLUSIONS: This study showed that, antithrombin III treatment significantly prevented the delaying effect of remote organ ischemia-reperfusion injury on anastomotic healing in the colon. Further clinical studies are needed to clarify whether antithrombin may be a useful therapeutic agent to increase the safety of the anastomosis during particular operations where remote organ ischemia-reperfusion injury takes place.     

血浆抗凝物质在深静脉血栓形成患者中的变化

目的研究抗凝血酶(AT)、蛋白 S(PS)、蛋白 C(PC)及活化蛋白 C 抵抗(APC-R)在深静脉血栓形成 (DVT)患者中的变化,探讨其与 DVT 的关系。方法采用发色底物法、ELISA 法、免疫浊度法检测100例 DVT 患者和 100例健康人的 AT 活性及含量、总 PS 含量、PC 活性及 APC-R。结果 DVT 组与正常对照组相比,AT 活性及含量、总 PS 含量、PC 活性均明显降低,差异呈显著性(P＜0.01～0.001)；本组100例 DVT 患者中共有25例患者存在有抗凝蛋白缺陷,以 PS 缺陷的总发生率最高,为13%(13例),PC 缺陷为8%(8例),AT 缺陷占5%(5例),APC-R 的总发生率最小,为4%(4例)。结论先天性或获得性抗凝蛋白缺陷是中国人 DVT 发病和复发的重要机制之一。中国人静脉血栓易栓症的病因组成比与西方国家不同,因此对每一 DVT 病人均应进行抗凝蛋白检测。     

血液肿瘤患者中血管性血友病因子、D二聚体、抗凝血酶检测的意义

目的探讨血液系统肿瘤患者血浆中血管性血友病因子(vWF)、D二聚体(D-D)、抗凝血酶(AT)水平变化及临床意义。方法以42例急慢性白血病、淋巴瘤、多发性骨髓瘤患者为观察对象,分初发组、缓解组、未缓解组、复发组,26例健康体检者为正常对照,测定血浆中vWF、D-D、AT水平。结果(1)初发血液肿瘤患者血浆中vWF、D-D水平明显高于正常对照组(P值均＜0．01)；缓解组vWF、D-D明显低于初发、对照组；复发患者vWF再次明显升高,与正常组和初发组比较差异有显著性(P＜0．01)；未缓解组vWF、D-D高于对照组和缓解组。(2)恶性肿瘤各组AT水平与对照组无明显差异(P＞0．05),但在疾病晚期AT明显降低(P＜0．01)。结论血液肿瘤患者存在不同程度的高凝状态,血浆vWF、D-D含量变化对病情和预后的评估有一定的参考价值,血浆AT水平降低是反映病情危重的指标。     

Plasminogen and tissue plasminogen activator interact with antithrombin III

Human antithrombin III was demonstrated to bind plasminogen specifically in a time and concentration-dependent manner. The above binding was also confirmed using ligand western blot assays. The interaction of plasminogen was significantly (>90%) inhibited by lysine, indicating the involvement of kringles in binding antithrombin III. Plasminogen also bound to heparin-antithrombin III complex. In converse experiments, antithrombin III also interacted with immobilized plasminogen. Using carboxypeptidase B digestion, the plasminogen-binding site of antithrombin III was localized to the carboxy-terminus lysine of the anticoagulant protein. Tissue plasminogen activator also interacted with antithrombin III in a time- and concentration-dependent manner and its binding was also significantly (>90%) inhibited by lysine. Moreover, the interaction of plasminogen and tissue plasminogen activator with antithrombin III was competitive. These results provide the first evidence for the interaction of antithrombin III with fibrinolytic factors and suggest that antithrombin III may serve to localize these factors at the site of clot formation.     

Hemostatic problems and thromboembolic complications in nephrotic children

A hypercoagulable state and the risk of thromboembolism in both arterial and venous circulation is a relatively frequent and serious feature of nephrotic syndrome (NS) in children and adults. The aim of this study was to evaluate the coagulation states of children with NS before and after corticosteroid (CS) therapy and to compare the results with a healthy control group. The first group consisted of 49 nephrotic children (30 boys and 19 girls) with a mean age of 6.5±4.9 years (range 1–16 years). The control group included 17 healthy children (9 boys and 8 girls). At the time of admission, all patients were evaluated for the presence of clinical thromboembolism, hematological and biochemical indicators of a hypercoagulative state, and renal disease. This was repeated after CS treatment. Deep vein thrombosis was observed in 2 nephrotic patients who had very low plasma antithrombin III (AT III) levels and fibrinogen levels above 750 mg/dl. Thus, the prevalence of thromboembolism was 4% in our pediatric nephrotic population. The mean AT III level of the study group was 68.2±23.4% at the onset of the disease, which was significantly lower than the level of the control group (84.0±7.6%). Plasma AT III levels increased to 74.4±15.3% after CS treatment, which correlated with the serum albumin levels. However, there was no correlation with urinary protein excretion. Protein C levels were higher than controls during all stages of the disease in both steroid-responsive and -unresponsive patients. The mean protein S level was similar in both groups. Plasma fibrinogen and cholesterol levels were significantly higher in the study group but decreased to within normal limits with remission. Our study suggests that thromboembolic complications are not infrequent in children with NS, and may be related to low plasma AT III and albumin and high fibrinogen and cholesterol levels. Received: 3 August 1998 / Revised: 27 May 1999 / Accepted: 1 June 1999     

Myocardial infarction in a neonate with hereditary antithrombin III deficiency

We report the case of a newborn girl with antithrombin III deficiency type 1. The clinical features of a hypercoagulable condition that lead to this rare diagnosis differed from the reports in the literature, since the primary thromboembolic incident resulted in neonatal myocardial infarction, which is in itself a rare condition during the first days of life.     

Chromogenic endotoxin determination in blood — clinical relevance

Summary In a pilot study in 400 patients LPS-quantification in blood using chromogenic substrates, bacterial cultures and bacterial quantification were performed. Decreased plasma levels of antithrombin III and plasminogen were early predictors of gram-negative septicemia, which already were apparant 3 days prior to the first positive LPS-test. It is concluded that daily determinations of LPS may reduce the delay in proper antibiotic therapy.     

Reduction of ischemia/reperfusion injury by antithrombin III after experimental pancreas transplantation

BACKGROUND: Graft pancreatitis is a major complication after pancreas transplantation. Antithrombin III (AT III) is an anticoagulatory and anti-inflammatory substance. The aim of our study was to evaluate a prophylactic application of AT III in experimental pancreas transplantation. METHODS: Pancreas transplantation was performed in rats. Cold ischemia time (University of Wisconsin solution at 4 degrees C) was 12 hours. After 4 hours of reperfusion, pancreatic enzymes were assessed and the pancreas was evaluated by intravital microscopy and histologic and immunohistochemical examination. Recipients were allocated randomly to 2 groups: 1 control group (n = 6) and 1 group in which recipients received 125 IU AT III/kg 30 minutes before reperfusion (n = 6). Six animals that did not undergo transplantation served as healthy controls. RESULTS: Enzyme levels showed no differences between the 2 transplantation groups but were significantly (P <.05) higher than in the control group. Histologic damage was significantly less evident in animals that received AT III compared with transplantation animals that did not receive AT III. During intravital microscopy, animals receiving AT III showed significantly higher capillary and venular erythrocyte velocities compared with untreated transplantation animals. The leukocyte-endothelium interaction in postcapillary venules was decreased significantly in animals with AT III treatment. CONCLUSIONS: AT III pretreatment decreases tissue damage by attenuating microcirculatory disturbances and leukocyte adherence in experimental graft pancreatitis by its anti-inflammatory and anticoagulatory properties.     

Antithrombin III attenuates pulmonary tissue injury caused by mesenteric ischemia-reperfusion

BACKGROUND: Mesenteric ischemia-reperfusion (I/R) is a well-known event causing both local and remote organ injuries, including the lungs. Recently, several studies indicated that activated leukocyte-endothelial cell interactions play an important role in the mechanisms of these injuries. As a natural inhibitor of serine proteases, antithrombin was shown previously to attenuate the tissue damage after local I/R in several organ systems. Here, we examined the effects of antithrombin on pulmonary injury after mesenteric I/R. METHODS: Wistar albino rats underwent median laparotomy and were randomized into 3 groups: (1) sham-operated control (n = 12), (2) 60 minutes of mesenteric ischemia and 3 hours of reperfusion (n = 12), and (3) antithrombin-pretreated (250 U/kg) group before the I/R (n = 12). At the end of reperfusion, animals were killed and neutrophil sequestration, myeloperoxidase (MPO) activity, and Evans blue dye extravasation in the lung parenchyma were assessed and compared. RESULTS: There was a statistically significant increase in the quantity of Evans blue dye concentration, leukocyte sequestration, and MPO activity in the I/R group when compared with the control group. The pretreatment of animals with antithrombin significantly decreased the pulmonary injury characterized by increased Evans blue dye extravasation, leukocyte sequestration, and MPO activity. CONCLUSION: The data of the present study suggest that mesenteric ischemia and reperfusion induces pulmonary injury characterized by activated neutrophil sequestration and increased microvascular leakage in the lungs. A significant attenuation of intestinal I/R-related lung injury with the use of antithrombin concentrate warrants further studies to elucidate the potential role of this natural serine protease inhibitor in clinical settings.