M. Cyr et al., Anomaly of the des-Arg(9)-bradykinin metabolism associated with severe hypotensive reactions during blood transfusions: a preliminary study, TRANSFUSION, 39(10), 1999, pp. 1084-1088
BACKGROUND: Severe hypotensive reactions have been described after the tran
sfusion of platelets or red cells through negatively-charged bedside white
cell-reduction filters. The possibility of a role for bradykinin (BK) in th
e genesis of these reactions has been raised.
STUDY DESIGN AND METHODS: To understand if an anomaly of BK metabolism is a
ssociated with these reactions, the metabolism of BK and des-Arg(9)-BK was
studied in the sera of four patients who presented with a severe hypotensiv
e transfusion reaction; Tests were performed in the absence and the presenc
e of complete in vitro inhibition of angiotensin-converting enzyme (ACE) ac
tivity 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 hypo
tensive transfusion reaction (361 +/- 90 sec) was not significantly differe
nt from that measured in the sera of normal controls (249 +/- 16 sec). In t
he presence of ACE inhibition (enalaprilat), the t1/2 of des-Arg(9)-BK was
significantly greater in patients who presented with a severe hypotensive t
ransfusion reaction (1549 +/- 319 sec) than in normal controls (661 +/- 38
sec) (p<0.001).
CONCLUSION: A metabolic anomaly mainly affecting the degradation of des-Arg
(9)-BK could be responsible for its accumulation in vivo. Des-Arg(9)-BK cou
ld be responsible, at least in part, far severe hypotensive transfusion rea
ctions.