Delorme M A, Saeed N, Sevcik A, Mitchell L, Berry L, Johnston M, Andrew M
Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada.
Blood. 1993 Dec 1;82(11):3380-5.
A 68-year-old man on chronic hemodialysis for 6 years, presented with a spontaneous psoas muscle hemorrhage. Investigations showed intermittently elevated activated partial-thromboplastin time and thrombin time. Preliminary investigations suggested a heparin-like inhibitor in the patient's plasma, but no anti-Xa activity could be detected. Investigation of the ability of patient plasma to inhibit exogenous thrombin showed that most thrombin was inhibited by heparin cofactor II, in contrast to normal plasma in which most thrombin was inhibited by antithrombin III. Treatment of plasma with glycosaminoglycan-degrading enzymes suggested the presence of dermatan sulfate (DS) in patient plasma. This was confirmed in a heparin cofactor II-dependent antithrombin assay for DS that showed anticoagulant equivalent to 2.2 +/- 0.3 micrograms/mL (mean +/- SD) of porcine mucosal DS. Of this activity, approximately 90% was sensitive to enzymes that degrade DS. The glycosaminoglycan containing fraction of plasma was isolated and subjected to gel chromatography. Anticoagulant activity eluted from Sephadex G-100 (Pharmacia, Montreal, Quebec, Canada) as two peaks with Kav of 0.10 and 0.45. After treatment with base, the Kav of the higher molecular weight species was increased to 0.55. This activity was completely sensitive to enzymes that degrade DS. Thus, the active DS was present as a proteoglycan. The lower molecular weight material was not sensitive to enzymes that degrade DS or heparan sulfate and it was active in the heparin cofactor II-dependent antithrombin assay but not in an antithrombin III-dependent antithrombin assay. This activity was not degraded by heating. Subsequently, measurement of DS activity was performed in plasmas obtained from eight other patients on hemodialysis before administration of heparin that showed that all patients had DS activity present that varied from 0.05 to 0.4 microgram/mL. No enzyme-resistant activity could be shown in these patients. In summary, a circulating anticoagulant with properties of DS is present in patients requiring hemodialysis.
一名68岁男性，已进行6年慢性血液透析，出现自发性腰大肌出血。检查显示活化部分凝血活酶时间和凝血酶时间间歇性升高。初步检查提示患者血浆中存在类肝素抑制剂，但未检测到抗Xa活性。对患者血浆抑制外源性凝血酶能力的研究表明，与正常血浆中大部分凝血酶被抗凝血酶III抑制不同，该患者血浆中的大部分凝血酶被肝素辅因子II抑制。用糖胺聚糖降解酶处理血浆提示患者血浆中存在硫酸皮肤素（DS）。在一项依赖肝素辅因子II的DS抗凝血酶测定中得到证实，该测定显示抗凝活性相当于2.2±0.3微克/毫升（平均值±标准差）的猪黏膜DS。在该活性中，约90%对降解DS的酶敏感。分离血浆中含糖胺聚糖的部分并进行凝胶色谱分析。从Sephadex G - 100（Pharmacia，蒙特利尔，魁北克，加拿大）洗脱的抗凝活性呈现两个峰，其分配系数（Kav）分别为0.10和0.45。用碱处理后，较高分子量物质的Kav增加到0.55。该活性对降解DS的酶完全敏感。因此，活性DS以蛋白聚糖形式存在。较低分子量物质对降解DS或硫酸乙酰肝素的酶不敏感，并且在依赖肝素辅因子II的抗凝血酶测定中有活性，但在依赖抗凝血酶III的抗凝血酶测定中无活性。该活性不被加热降解。随后，在另外8名血液透析患者肝素给药前采集的血浆中进行DS活性测定，结果显示所有患者均存在DS活性，范围为0.05至0.4微克/毫升。这些患者中未显示出酶抗性活性。总之，需要血液透析的患者体内存在具有DS特性的循环抗凝剂。
