Clinical and Laboratory Investigations

Acquired Angioedema with C1 Inhibitor Deficiency: Is the Distinction between Type I and Type II Still Relevant?
Michel D'Incan^a, Arlette Tridon^b, Denise Ponard^d, Chantal Dumestre-Pérard^d, Marie-Christine Ferrier-Le Bouedec^a, Georges Bétail^b, Pierre Souteyrand^a, Denis Caillaud<sup>c

a</sup>Department of Dermatology, CHRU Hôtel-Dieu,
^bLaboratory of Immunology, Faculty of Medicine, and
^cDepartment of Pneumology and Allergology, Hôpital Gabriel-Montpied, Clermont-Ferrand, and
^dLaboratory of Immunology, CHRU Hôpital sud, Grenoble, France

Address of Corresponding Author

Dermatology 1999;199:227-230 (DOI: 10.1159/000018252)

  Key Words

• Acquired angioedema
• Complement
• C1 inhibitor antibodies

  Abstract

Background: Acquired angioedemas are divided into type I associated with lymphoproliferation and type II caused by anti-C1-inhibitor antibodies. Recent reports have suggested that this distinction is not so clear-cut, mainly because of the presence of antibodies against the C1 inhibitor in some cases belonging to the type I group. We report herein 2 additional cases of acquired angioedema with anti-C1-inhibitor antibody. Material and Methods: One man and 1 woman had had acquired angioedema for several years. In the man, a monoclonal component had been detected several years before the present study. In the second patient, a monoclonal component was detected during the study. The following data were studied on successive blood samples collected during angioedema manifestations: complement component levels, functional activity of the classical pathway, functional and antigenic C1 inhibitor doses, ELISA test to detect autoantibodies to C1 inhibitor and Western blot analysis of the C1 inhibitor. Results: In both patients, CH50 and C4 activities were decreased, and an autoantibody to C1 inhibitor was detected. In 1 case, the antibody appeared after the monoclonal component; in the second case, it appeared before and belonged to a different immunoglobulin class. Conclusion: Our data suggest that the distinction between type I and type II acquired angioedema is no longer valid because of overlapping in some cases.

  Author Contacts

Michel D'Incan
Department of Dermatology, CHRU Hôtel-Dieu
Avenue Charles-de-Gaulle, F-63000 Clermont-Ferrand (France)
Fax +33 0473316177
E-Mail mc.dincan@wanadoo.fr

  Article Information

Received: Received: December 11, 1998
Accepted: July 8, 1999
Number of Print Pages : 4
Number of Figures : 0, Number of Tables : 1, Number of References : 12