Relationship between kallikrein release and factor XII in normal persons and carriers of the Hageman trait.

In four healthy subjects with Factor XII levels equal to or below 50% (selected at random from 100 persons) the release of Kallikrein was studied in order to establish the relationship between the above data and those found in four Hageman trait carriers showing levels of Factor XII above the lowest normal limits. It was found that for similar amounts of Hageman activity three of the carriers showed significantly less release of Kallikrein than the control subjects in whom it was normal. The conclusion was reached that the additional determination of the amount of Kallikrein released may be of value in the detection of carriers of the Hageman trait.