Hemolytic uremic syndrome in children: platelet aggregation and membrane glycoproteins.

PURPOSE Several mechanisms have been proposed to explain the fibrin-platelet thrombosis at the microcirculation level in the different clinical conditions of hemolytic uremic syndrome (HUS). The relationships between platelet structure and function during the first 4 weeks of evolution of the disease were studied to understand the mechanism of platelet alteration. PATIENTS AND METHODS Coagulation parameters, platelet counts, and aggregation were studied in 49 children, and membrane glycoproteins (GPs) in 20 of the 49 children (mean age, 17 months) with HUS (Group 2) were studied during the first 4 weeks of evolution of the disease. RESULTS No disseminated intravascular coagulation was found in patients with recurrent or persistent thrombocytopenia. Platelet aggregation was sequentially performed during the first weeks of evolution. All patients had a functional decrease in the acute period of HUS. Platelet GPs GPIb, GPIIbIIIa, GPIIb, and GPIIIa were evaluated. GPIIbIIIa complex presented low level and never reached normal values during the first 4 weeks of disease. CONCLUSIONS Platelet alterations are probably caused by multiple mechanisms: "exhausted" platelets, structural membrane alterations caused by arginine-glycine-aspartic peptide blockade, or diminished or nonfunctional membrane GPIb and GPIIbIIIa complexes.

目的 已经提出了几种机制来解释溶血性尿毒症综合征（HUS）不同临床情况下微循环水平的纤维蛋白 - 血小板血栓形成。研究了疾病发生最初4周内血小板结构和功能之间的关系，以了解血小板改变的机制。 患者与方法 对49名儿童的凝血参数、血小板计数和聚集情况进行了研究，并对其中20名（平均年龄17个月）患有HUS的儿童（第2组）在疾病发生最初4周内的膜糖蛋白（GPs）进行了研究。 结果 在复发或持续性血小板减少症患者中未发现弥散性血管内凝血。在疾病发生的最初几周内依次进行血小板聚集检测。所有患者在HUS急性期都有功能下降。对血小板糖蛋白GPIb、GPIIbIIIa、GPIIb和GPIIIa进行了评估。GPIIbIIIa复合物水平较低，在疾病最初4周内从未达到正常水平。 结论 血小板改变可能由多种机制引起：“耗竭”的血小板、由精氨酸 - 甘氨酸 - 天冬氨酸肽阻断引起的膜结构改变，或者膜GPIb和GPIIbIIIa复合物减少或无功能。