Unexpected Occurrence of the Ca 19-9 Tumor Marker in Normal Human Seminal Plasma

Abstract

A monoclonal antibody with anti-sialyl-lacto-N-fucopentaose II specificity, originally thought to be a specific tumor marker in pancreas- and gastrointestinal tumors, reacts strongly with fucose-rich glycoproteins from human seminal plasma obtained by phenol/saline extraction. They are presumed to come from the prostatic gland secretion. Because of the specificity of this monoclonal antibody it can be deduced that the sialyl-Lea-sequence: N-acetyl-.alpha.-neuraminyl-(2 .fwdarw. 3)-.beta.-D-galactopyranosyl-(1 .fwdarw. 3)-[.alpha.-L-fucopyranosyl-(1 .fwdarw. 4)]-2-acetamido-2-deoxy-.beta.-D-glucopyranosyl-(1 .fwdarw. 3)-D-galactopyranosyl is present on these glycoproteins. This is also supported by carbohydrate analysis.