Bradykinin-associated reactions in white cell-reduction filter

The purpose of this study was to examine the effect of temperature on bradykinin generation during blood transfusion using positively charged (positive filter), negatively charged (negative filter), and neutral (neutral filter) filters.

Whole blood collected from six volunteers at 4 degrees C or 37 degrees C was passed through the positive or negative filter. In six surgical patients during surgery, autologous blood transfusion at 37 degrees C was initiated through the positive filter, and the same transfusion was reintroduced through the negative filter. Whole blood from another six volunteers at 4 degrees or 37 degrees C was passed through the neutral filter.

The positive filter did not generate bradykinin at any temperature, whereas the negative filter generated bradykinin by approximately 4,000-fold when warm blood was used but did not at cool blood. Blood pressure decreased and heart rate increased during warm blood transfusion using the negative filter but did not change using the positive filter. Plasma bradykinin levels increased in patients with use of the negative filter. The neutral filter generated bradykinin when warm blood was used but at levels lower than for the negative filter.

Use of negative filter results in the temperature-dependent generation of bradykinin, which becomes a potential anaphylatoxin when warm blood is used.