Aminopeptidase P in individuals with a history of angio-oedema on ACE inhibitors

Lancet. 2002 Jun 15;359(9323):2088-9. doi: 10.1016/S0140-6736(02)08914-6.


Angio-oedema is a rare but potentially life threatening side-effect of angiotensin-converting-enzyme (ACE) inhibitor treatment. Identification of individuals at risk of this adverse effect is not possible. Angio-oedema is associated with raised concentrations of bradykinin, which is mainly inactivated by ACE. We assessed the plasma activity of two other enzymes that catabolise bradykinin (aminopeptidase P and carboxypeptidase N) in 39 hypertensive patients with a history of angio-oedema during ACE inhibitor treatment and in 39 hypertensive patients who had never had ACE inhibitor associated side-effects. Patients with previous angio-oedema had a lower plasma activity of aminopeptidase P than did those who never presented with angio-oedema (p=0 003). Our data suggest that low plasma concentrations of aminopeptidase P could be a predisposing factor for development of angio-oedema in patients treated with ACE inhibitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aminopeptidases / blood*
  • Analysis of Variance
  • Angioedema / blood
  • Angioedema / chemically induced*
  • Angioedema / enzymology
  • Angiotensin-Converting Enzyme Inhibitors / adverse effects*
  • Case-Control Studies
  • Humans
  • Hypertension / drug therapy
  • Lysine Carboxypeptidase / blood*
  • Middle Aged


  • Angiotensin-Converting Enzyme Inhibitors
  • Aminopeptidases
  • X-Pro aminopeptidase
  • Lysine Carboxypeptidase