In 1933 Tillett and Garner1 demonstrated in cultures of hemolytic streptococci a freely excreted extracellular substance which had the property of dissolving solid human fibrin. They also reported that the fibrin from patients recently recovered from hemolytic streptococcic infections often became completely resistant to the fibrinolytic action of hemolytic streptococci. As a result of early observations in this field it was believed that the reaction was a specific immunity response, because patients who had recovered from nonstreptococcic infections did not show this antifibrinolytic reaction. This view is now known to be erroneous, because subsequent investigations by Wadler,2 Harris3 and others have demonstrated resistance to fibrinolysis in a small percentage of normal persons and in a large percentage of patients with pneumonia or other infection.
In preliminary studies of normal persons and of patients with various types of infection we were able to demonstrate the fibrinolytic activity of