Comparative study of alpha 1-acid glycoprotein molecular variants in ascitic fluid of cancer and non-cancer patients.

alpha 1-Acid glycoproteins (alpha 1-AG) were collected from the ascites of patients with liver cirrhosis or liver cancer, respectively, and their physical, chemical, and biological properties were compared. The substance obtained from patients with liver cancer showed a 2-3 times higher inhibitory effect on [3H]thymidine uptake by human peripheral lymphocytes stimulated with PHA than that obtained from patients with cirrhosis. The two substances showed differences in their affinity to wheat germ agglutinin (WGA) and concanavalin A (Con A). Of the fractions obtained by lectin affinity chromatography, the Con-A bound fraction showed the greatest lymphocyte proliferation inhibitory activity. The alpha 1-AG levels were elevated in both the patients with cancer and those with infectious disease, but the level of the Con-A bound fraction was elevated only in those with cancer. This study suggests that the molecular variants of alpha 1-AG differ in their carbohydrate structure with the disease, and that the cellular immunity of the host way be partially controlled by changes in the content of these molecular variants.