An antibody that recognizes a determinant common to S and s-bearing sialoglycoproteins

Abstract
An antibody, made by an individual [human] of the phenotype M+,N+,S+,s+,U+, that reacted only with ficin or papain-treated [human] red blood cells, and that initially appeared to have anti-S specificity is described. Further studies revealed that the antibody, which did not have anti-U specificity, recognized a determinant present on S+,s-,U+, and S-,s+,U+, but missing from S-,s-,U-, and S-,s-,U+, red blood cells. The specificity of this antibody is discussed in terms of current knowledge of the structure of the [blood group] Ss sialoglycoprotein.