Further Observations on the Serologic Specificity of Sialic Acid for Rh_o(D) Antibody

The previous work showing that certain crude preparations of N -acetylneuraminic acid (NANA), a brain ganglioside containing NANA, and degradation products such as N -acetylglucosamine and mannosamine specifically inhibited Rh _o (D) antibody has been found to be dependent on factors such as the time of incubation of inhibitor and antiserum, the amount of antibody used and the nature of the preparation. Absorption of anti-D serum with D-negative cells to which these substances had been coupled demonstrated that NANA from human plasma which did not inhibit, and poor inhibitors such as N -acetylglucosamine, bound anti-D and removed it from serum as efficiently as good inhibitors.