Angioedema and oral contraception.
BACKGROUND
Oral contraceptives can precipitate attacks of hereditary angioedema (ANE) or induce acquired forms.


OBJECTIVE
We studied 5 patients who had an ANE which had begun under oral contraception and disappeared after stopping the pill.


METHODS
We explored the clinical and biological characteristics of these patients.


RESULTS
The symptoms developed during the first year or later after starting contraception; the patients reported relapsing swelling of the lips, hands, larynx and abdomen. All women had normal serum C4 and C1 inhibitor (C1Inh) antigen levels, but a lowered C1Inh activity, with a marked protein cleavage on the immunoblot. The suppression of the pill was associated with the regression of the edema and normalization of C1Inh function.


CONCLUSIONS
The mechanism of these ANE is unknown. The could be due to a modulation of C1Inh expression upon androgens or an imbalance between coagulation proteins favoring C1Inh cleavage by its target proteases.
Bouillet
L
L
Département pluridisciplinaire de médecine, Service de médecine interne, Hôpital Sud, CHU de Grenoble, France. LBouilletClaveyrolas@chu-grenoble.fr
Ponard
D
D
Drouet
C
C
Jullien
D
D
Massot
C
C
D000328:Adult; D000799:Angioedema / Q000139:chemically induced* / Q000276:immunology; D003174:Complement C1 Inactivator Proteins; D050718:Complement C1 Inhibitor Protein; D003278:Contraceptives, Oral, Hormonal / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015151:Immunoblotting; D012189:Retrospective Studies; D015843:Serpins / Q000097:blood
D003174:Complement C1 Inactivator Proteins; D050718:Complement C1 Inhibitor Protein; D003278:Contraceptives, Oral, Hormonal; C469952:SERPING1 protein, human; D015843:Serpins