Comparisons were made between the seromucoid (perchloric acid soluble, phosphotungstic acid precipitable glycoprotein) fraction of serum from normal subjects and from patients with malignant neoplastic diseases. The seromucoid of normal human serum was separated into eight (I through VIII) fractions by DEAE-cellulose chromatography using a phosphate buffer gradient. The protein, hexose and hexosamine contents and hexosamine/protein ratios were different for the various fractions. Immunoelectrophoretic activity against commercially available antisera was detected in fractions 111 to VII of normal seromucoid. The fractions differed from each other in disc electrophoresis patterns. Seromucoid from patients with certain diseases revealed alterations in the above parameters. It is possible that some of the evidence of heterogeneity of the fractions is due to preparative artefacts; however, it is also evident that the seromucoid fractions from pathologic sera differ from normal, despite the same preparative treatments. Malignant neoplasms are characterized by alterations in the fractions eluted early in the scheme and other diseases by fractions eluted in the intermediate range. Immunoelectrophoretic and disc electrophoretic studies further demonstrate qualitative differences between the seromucoid fractions from normal and pathologic states.
UANTITATIVE CHANGES IN THE LEVELS OF
serum seromucoid have been reported in various neoplastic and non-neoplastic diseases37 4, 1 4 7 but there are relatively few data on qualitative changes in this heterogeneous fraction. In one approach to such study, Moschides et al.14 showed on the basis of hexose/protein ratios and hexosamine/protein ratios that it was probable that qualitative changes also occur in this fraction in several diseases. Based on these data, those authors concluded that this fraction of serum proteins represented a mosaic in which changes within the structure, as well as in the total amounts, occur in various disorders.