The Australia (hepatitis-associated) antigen in fibrinogen and other fractions of human plasma.

Human plasma containing the Australia (hepatitis-associated) antigen was fractionated by the cold ethanol method of Cohn, Strong, Hughes, Mulford, Ashworth, Melin, and Taylor (1946) and small aliquots were examined for the presence of this antigen by immunodiffusion and by electron microscopy. The findings were in general agreement with the postulated risk of transmitting hepatitis by blood derivatives. The Australia (hepatitis-associated) antigen was detected in fibrinogen, thrombin, and antihaemophilic globulin as well as in other fractions. The antigen was not found in gamma globulin (immunoglobulin fraction) nor in albumin.The use of radioiodinated fibrinogen for the diagnosis of deep vein thrombosis is discussed and it is concluded that the use of fibrinogen for diagnostic procedures should be assessed against the possible risk of hepatitis.