Effect of a synthetic poly N-(2-hydroxypropyl)methacrylamide (Duxon) on haemopoiesis and graft-versus-host reaction.

: A synthetic polymer, Duxon, was developed and tested as a substitute of blood plasma for transfusion purposes. Tests of this preparation included a test for its influence on the haemopoietic stem cells and the graft-versus-host reaction (GVHR). A single dose or repeated doses of Duxon did not reduce the number of pluripotent haemopoietic colonies (CFU-S) in mice and short-term incubation of cells from haemopoietic organs of mice with Duxon resulted in a slight, yet significant, increase in the number of CFU-S. Injection of Duxon non-significantly diminished the manifestations of the regional GVHR. Incubation of spleen cells with Duxon significantly reduced their GVH reactivity in the regional test. The systemic GVHR was moderately inhibited by repeated doses of Duxon in sublethally irradiated mice. A significant delay in deaths of animals from GVHR was seen in lethally irradiated mice receiving a single dose of Duxon on day 4 after GVHR induction. Survival of lethally and sublethally irradiated mice was prolonged following injection of cells incubated with Duxon. Possible uses of Duxon, a preparation with mild immunosuppressive properties, not impairing haemopoiesis, are discussed.