Study on immunosuppressive activity of alpha-globulin fraction of human blood plasma.

Immunosuppressive activity of alpha-globulin fraction of human blood plasma (Cohn fraction IV) was studied to determine the possible clinical utilization of this fraction as such, purified, or as the starting material for isolation of the active factor. The ethanol fractions IV, isolated and waste in the production of blood derivatives were found to be directly inapplicable because of relatively low activity and poor solubility. Therefore purification experiments were done to remove the denatured proteins and lipids and to increase the specific activity, they were performed on laboratory scale using DEAE ionex chromatography, and on semipilot scale utilizing the principles of ethanol fractionation of plasma. From the viewpoint of technology, the latter procedure seems more feasible; partial purification yielded good solubility and somewhat higher specific activity. Under study are further techniques capable of eliminating the contaminating proteins with do not carry the immunosuppressively active component, as well as the effectivity of pasteurization at 60 degrees C/10 hrs., which seems indispensable with respect to inactivation of infectious hepatitis viruses and the potential clinical application. Experimental isolations of the active component have led immunosuppressively active low-molecular part, which, however, is chemically nonhomogeneous. Its subsequent subfractionation will be necessary.