Immunosuppressive and immunostimulatory activity of human cancer ascitic fluids has been examined using the in vitro primary plaque-forming cell response (PFR) to sheep erythrocytes (Mishell-Dutton assay). We have prepared three fractions of ascitic fluid by precipitation with ammonium sulfate. Suppressive activity occurred in the fraction which was insoluble at 50% of saturation but not those fractions which precipitated at 30 or 80% of saturation. The fractions which were precipitated at 30 and 80% were stimulatory in the assay system. Normal human serum also had suppressive activity in the fraction precipitated at 50% of saturation but not as much as was found in ascitic fluid. Serum did not yield any fractions with stimulatory activity. © 1976.
Badger, A. M., Merluzzi, V. J., & Cooperband, S. R. (1976). Immunostimulatory and immunosuppressive factors in human cancer ascites fluids: Effect on the primary plaque-forming response in vitro. Cellular Immunology, 27(1), 126–130. https://doi.org/10.1016/0008-8749(76)90161-1