Specific inhibition of RHo(D) antibody by sialic acids.

Agglutination of Rh(O)(D) erythrocytes by specific antiserum was inhibited by crude and crystalline N-acetylneuraminic acid, less inhibited by its glycoyl derivative, and weakly inhibited by its degradation product, N-acetyl-mannosamine, and by D-mannose. A brain ganglioside containing neuraminic acid and a Pseudomonas polysaccharide were even more inhibitory. Inhibition was specific for anti-D sera.