Anomaly of the des-Arg9-bradykinin metabolism associated with severe hypotensive reactions during blood transfusions: a preliminary study
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Published on: April 17, 2020
1School of Pharmacy, University of Montréal, Québec, Canada.
Background:
Severe hypotensive reactions have been described after the transfusion of platelets or red cells through negatively-charged bedside white cell-reduction filters. The possibility of a role for bradykinin (BK) in the genesis of these reactions has been raised.
Study Design And Methods:
To understand if an anomaly of BK metabolism is associated with these reactions, the metabolism of BK and des-Arg9-BK was studied in the sera of four patients who presented with a severe hypotensive transfusion reaction. Tests were performed in the absence and the presence of complete in vitro inhibition of angiotensin-converting enzyme (ACE) activity by enalaprilat.
Results:
In the presence of ACE inhibition (enalaprilat), the half-life (t1/2) of BK measured in the sera of patients who presented with a severe hypotensive transfusion reaction (361 +/- 90 sec) was not significantly different from that measured in the sera of normal controls (249 +/- 16 sec). In the presence of ACE inhibition (enalaprilat), the t1/2 of des-Arg9-BK was significantly greater in patients who presented with a severe hypotensive transfusion reaction (1549 +/- 319 sec) than in normal controls (661 +/- 38 sec) (p < 0.001).
Conclusion:
A metabolic anomaly mainly affecting the degradation of des-Arg9-BK could be responsible for its accumulation in vivo. Des-Arg9-BK could be responsible, at least in part, for severe hypotensive transfusion reactions.

