The total plasmin and the trypsin inhibitor were titrated separately in samples of serum taken at weekly intervals from three different groups of scarlet fever patients: (a) those who did not develop any complications, (b) those who developed purulent complications, and (c) those who developed rheumatic fever.
When these determinations were plotted, it was found that the resulting curves showed characteristic patterns for each of the diseases investigated.
The uncomplicated cases had plasmin curves which were considerably higher on the charts than the inhibitor curves.
The septic cases had plasmin and inhibitor curves which were closer together on the charts.
The rheumatic cases had plasmin and inhibitor curves which were close together and which crossed at the time of rheumatic activity so that the inhibitor curve reached a higher level than the plasmin curve.