Two Examples of Sera Containing the Anti-d Agglutinin Predicted by Fisher and Race

Abstract

Two sera which have been shown to contain the anti-d antibody have been referred to us by Dr. E. E. Dilworth of Shreveport, Louisiana, and Drs. J. W. Davenport and Bruce Everist of New Orleans, Louisiana. The first case, an iso-immunized mother of type CDe/CDe, produced a high titre of anti-c agglutinin which was greatly increased by the administration of small doses of cde/cde cells. Studies of the antibodies produced during this programme of stimulation showed the development of an anti-d antibody demonstrated by agglutination with CDe/Cde red cells. The second serum was also from a mother of genotype CDe/CDe. Fortunately the serum from this iso-immunized mother contained an anti-d agglutinin active with saline suspensions of red cells, while the anti-c antibody present at about equal titre did not react with saline erythrocyte suspensions but could be demonstrated with the Coombs (developing) test or with a suspension of erythrocytes in albumin. Using the classical test-tube method with saline suspensions of test erythrocytes, this serum agglutinated cells of the following genotype: CDe/cde, cde/cde and CDe/Cde, but failed to agglutinate cells of genotype CDe/CDe, C^wDe/CDe, cDE/cDE and CDe/cDE. However, when the Coombs anti-human globulin method¹ was used to detect the antibodies, all erythrocytes containing the c antigen and/or the d antigen gave positive tests. The same results could be obtained by using albumin suspensions of erythrocytes by the method of Diamond and Denton². Further agglutination studies ruled out any correlation with A, B, M, N or P. The possibility of the agglutinins present in these sera being identical to the anti-Kell³, anti-Lutheran⁴ and anti-Lewis⁵ agglutinins was also ruled out by parallel tests with sera supplied by Mourant and Race.