Roelcke D, Kreft H, Northoff H, Gallasch E
Institute of Immunology, University of Heidelberg, Germany.
Transfusion. 1991 Sep;31(7):627-30. doi: 10.1046/j.1537-2995.1991.31791368339.x.
Postinfection cold agglutinins (CAs) with anti-Sia-b1 (i.e., anti-Sialo-branched) specificity frequently occurring together with anti-I CAs recognize antigenic determinants that are present on Oh red cells and are partially destroyed by endo-beta-galactosidase on the red cell surface. They differ markedly from the monoclonal anti-Sia-b1 FI CA, which recognizes an epitope not expressed on Oh cells, and resistant to the enzyme. On the other side, Sia-b1 determinants reacting with postinfection CAs share the characteristics of I determinants, with the exception that Sia-b1 determinants require sialyl groups as an immunodominant component. Five sera containing coexisting anti-Sia-b1 and anti-I CAs were tested against Oh and enzyme-treated group O red cells. The results are consistent with a postinfection autoimmune response against a sialo-type 2 structure common for Sia-b1 and I determinants, which could serve as a receptor for Mycoplasma pneumoniae.
感染后冷凝集素（CAs）具有抗Sia-b1（即抗唾液酸分支）特异性，常与抗-I CAs同时出现，其识别存在于Oh红细胞上的抗原决定簇，且该抗原决定簇在红细胞表面会被内切β-半乳糖苷酶部分破坏。它们与单克隆抗Sia-b1 FI CA明显不同，后者识别的表位在Oh细胞上不表达且对该酶有抗性。另一方面，与感染后CAs反应的Sia-b1决定簇具有I决定簇的特征，不同之处在于Sia-b1决定簇需要唾液酸基团作为免疫显性成分。对五份同时含有抗Sia-b1和抗-I CAs的血清进行了针对Oh和酶处理的O型红细胞的检测。结果与针对Sia-b1和I决定簇共有的唾液酸2型结构的感染后自身免疫反应一致，该结构可能作为肺炎支原体的受体。
