抄録
Natural blood group antibodies in human sera were fractionated by DEAE-cellulose column chromatography and eluted immunoglobulins were divided into three fractions composing respectively : 0.01 M initial potassium phosphate buffer, Fraction 1 (F 1); 0.125 M NaCl, Fraction 2 (F 2) and 0.25 M NaCl, Fraction 3 (F 3). The reaction of the fractions with anti-immunoglobulin sera in agar gel diffusion test revealed that F 1 contained IgG, F 2 IgA and a part of IgG, and F 3 IgM and traces of IgG and IgA. Agglutinations with red cells were tested before and after 2-mercaptoethanol treatment by saline and papain cells, and the anti-globulin method.
1) The natural anti-A and anti-B antibodies of groups B and A sera were of IgM molecular type and in some cases, eventually IgG and IgA, contrasting with the anti-A B of group O sera which contained higher titer of IgG. The results of Protein A-Sepharose CL-4B affinity chromatography showed that the IgG subclass of F 1 and F 2 belong to IgG 1. IgM and IgG anti-H antibodies were detected in serum from Bombay phenotype. Anti-A1 activity in group B serum belonged to IgM and IgA, and anti-A, antibody in group A2 serum constituted only by IgM class.
2) Natural anti-Lea antibodies of Le (a-b-) individuals belonged exclusively to the IgM class and some sera contained IgA class. The agglutination of natural anti-Lea antibodies was enhanced by papain treated red cells.
3) The fact that the activity of anti-P from group PK and anti-P1+P+PK of group p persons are found in IgG class is able to explain that the antibodies pass the placenta early in pregnancy and cause groups PK and p mothers to the consecutive miscarriages.
