Sondag-Thull D, Levene N A, Levene C, Manny N, Liew Y W, Bird G W, Schechter Y, François-Gérard C, Huet M, Blanchard D
Laboratoire des Groupes Sanguins et de Transfusion, Université de Liège, Belgique.
Vox Sang. 1989;57(3):193-8. doi: 10.1111/j.1423-0410.1989.tb00822.x.
Th polyagglutinability is characterized by the agglutination of the red blood cells (RBC) by Arachis hypogaea, Medicago disciformis, Vicia cretica but, in contrast to the T phenomenon, not by Glycine max (Glycine soja). Because Th transformation of RBC has been obtained in vitro, the mechanism of Th polyagglutinability expression has been studied and reproduced experimentally. An enzyme with neuraminidase specificity has been isolated from the culture supernatant of Corynebacterium aquaticum, and further characterized (MW = 55,600 kDa, pH = 5.5, Km = 0.138 microM, Kcat = 0.22 micrograms). Reversely, Th transformation of RBC could be obtained by using other neuraminidases but in very mild conditions of hydrolysis. From our results, it can be concluded that by the release of less than 20 micrograms of sialic acid per 10(10) RBC, Th reactivity can be induced whereas hydrolysis of greater amounts of sialic acid (greater than 20 micrograms/10(10) RBC) give the classical T polyagglutinability.
Th多凝集性的特征是花生、盘状苜蓿、克里特巢菜可使红细胞（RBC）发生凝集，但与T现象不同的是，大豆（野大豆）不能使其凝集。由于RBC的Th转化已在体外实现，因此对Th多凝集性表达的机制进行了研究并通过实验再现。已从水生棒状杆菌的培养上清液中分离出一种具有神经氨酸酶特异性的酶，并对其进行了进一步鉴定（分子量=55,600 kDa，pH=5.5，米氏常数=0.138微摩尔，催化常数=0.22微克）。相反，使用其他神经氨酸酶在非常温和的水解条件下也可实现RBC的Th转化。根据我们的结果可以得出结论，每10¹⁰个RBC释放少于20微克唾液酸可诱导Th反应性，而大量唾液酸（大于20微克/10¹⁰个RBC）水解则产生经典的T多凝集性。
