Studies on agglutinating antibodies of group O serum against weak subgroup red cells

探讨了O群血清对弱亚群红细胞具有良好凝集活性的根本原因。用A、B组特异性免疫吸附剂亲和层析O、A、B组血清中的血型特异性抗体。对所获得的抗体组分分别进行了对A3B、Ax、BM和ABM细胞的强度测试。O群血清中的抗A、抗B和抗A、B均为弱亚群细胞的高效凝集剂，而B群中的抗A和A群血清中的抗B均为高效凝集剂。提示O群血清中抗A、抗B、抗A、B抗体参与了导致弱亚群细胞聚集的血清学反应。免疫扩散法和硫醇沉淀法检测结果表明，O组血清中的抗体均为Ig G抗体，而A、B组血清中均为Ig M抗体。由此可见，O群血清对弱亚群细胞具有良好的凝集活性是由于血清中存在抗A、B和A、B抗体所致。虽然已经用几种与ABO血型系统相关的合成原糖(Synsorb)进行了吸收试验，但目前还不能确定来自O群血清的抗体识别的群特异性抗原的结构是否与来自A、B群血清的抗体识别的不同。

The basic cause of superior agglutinating activities of group O serum against weak subgroup red cells was investigated. Blood group specific antibodies in group O, group A, and group B serum were fractionated by affinity chromatography with group A and group B specific immunoadsorbents. The antibody fractions obtained were tested for their strength against A_3B, Ax, Bm, and ABm cells, respectively. All of the anti-A, anti-B, and anti-A, B from group O serum were found to be highly effective agglutinators of weak subgroup cells in contrast to both of anti-A from group B and anti-B from group A serum. These findings suggest that anti-A, anti-B, and anti-A, B antibodies in group O serum take part in serological reactions leading to the agglutination of weak subgroup cells together. Furthermore, studies by the immunodiffusion method and the mercaptoethanol method revealed that all of the antibodies from group O serum were IgG antibodies, whereas those from group A and group B serum were IgM antibodies. Thus, it can be concluded that the superior agglutinating activities of group O serum against weak subgroup cells are attributed to IgG anti-A, IgG anti-B, and IgG anti-A, B antibodies present in the serum. Although the absorption test has been conducted with several kinds of synthetic origosaccharides (Synsorb) relevant to the ABO blood group system, whether the structures of group specific antigens recognized by the antibodies from group O serum differ from those by antibodies from group A and group B serum can not be decided at the present time.