Examination of baseline levels of carboxypeptidase N and complement components as potential predictors of angioedema associated with the use of an angiotensin-converting enzyme inhibitor.

Abstract

OBJECTIVE:

To determine if mean levels of complement components and carboxypeptidase N differed when comparing patients who exhibited angioedema following angiotensin-converting enzyme inhibitor therapy to those who received angiotensin-converting enzyme inhibitor therapy but did not have angioedema.

DESIGN:

Case-control study nested within an 8-week, open-label study of the use of quinapril hydrochloride for hypertension in 12275 patients.

SETTING:

Multicenter, with sites throughout the United States.

PATIENTS:

Of the 36 patients with angioedema described, 22 participated in the study. They were matched to 48 controls by age, sex, race, length of follow-up, and geographical region.

INTERVENTION:

All patients received quinapril therapy prior to participation in this case-control study.

MAIN OUTCOME MEASURES:

Levels of carboxypeptidase N, total hemolytic complement, C1 esterase inhibitor, and C4, along with questionnaire data, including a history of angioedema-like episodes and family history of angioedema.

RESULTS:

The 22 patients had significantly lower mean levels of carboxypeptidase N (kininase I) (P = .03) and C1 esterase inhibitor (P = .04) compared with the 48 matched controls, but all mean values were within normal laboratory ranges. A history of prior angioedema-like episodes was associated with an approximate 6-fold increase in the subsequent risk of angioedema following angiotensin-converting enzyme inhibitor therapy.

CONCLUSIONS:

Small differences in levels of carboxypeptidase N or C1 esterase inhibitor may contribute to an increased risk of angioedema with angiotensin-converting enzyme inhibitor therapy. Given the large overlap in the distributions of carboxypeptidase N and C1 esterase inhibitor levels, prior testing could not be used to evaluate angioedema risk for an individual patient considering angiotensin-converting enzyme inhibitor therapy. A history of prior angioedema-like episodes was associated with increased risk, but this result should be interpreted with caution because of possible recall bias.

• Authors: C Sigler, K Annis, K Cooper, H Haber, S Van deCarr
• Journal: Archives of dermatology (Arch Dermatol) Vol. 133 Issue 8 Pg. 972-5 (Aug 1997) ISSN: 0003-987X [Print] United States
• PMID: 9267242 (Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)

Chemical References

• Angiotensin-Converting Enzyme Inhibitors
• Isoquinolines
• Tetrahydroisoquinolines
• Complement System Proteins
• Lysine Carboxypeptidase
• Quinapril

Topics

• Angioedema (blood, drug therapy)
• Angiotensin-Converting Enzyme Inhibitors (therapeutic use)
• Case-Control Studies
• Complement System Proteins (analysis)
• Female
• Humans
• Isoquinolines (therapeutic use)
• Lysine Carboxypeptidase (blood)
• Male
• Predictive Value of Tests
• Quinapril
• Tetrahydroisoquinolines