A Case of Acquired C1 Esterase Inhibitor (C1-INH) Deficiency As the Presenting Manifestation of Common Variable Immune Deficiency (CVID)
Saturday, March 5, 2016
South Exhibit Hall H (Convention Center)
Andrew Parker, MD, David Hagin, MD, Summer E. Monforte, MD, Andrew G. Ayars, MD, Matthew C. Altman, MD

Acquired angioedema is a rare syndrome of recurrent episodes of angioedema without urticaria caused by an acquired deficiency of C1-INH. CVID is a heterogeneous primary immunodeficiency that is characterized by susceptibility to infections and immune dysregulation including autoimmunity. Here we offer a rare case report of a patient with angioedema due to acquired C1-INH deficiency presenting as the initial manifestation of CVID.


Flow cytometry immunophenotyping was performed at the Immunology Diagnostic Laboratory in Seattle, WA. ELISA testing for autoantibodies to C1q and C1-INH were performed by the Advanced Diagnostic Laboratories in Denver, CO.


This female patient presented at age 58 with episodic swelling of the face without urticaria. Workup for angioedema revealed a C4 level that was undetectable on multiple occasions. C1-INH level was 12 mg/dl (21-39) with 4% function. There was no family history of angioedema. C1q level was undetectable. Given findings consistent with acquired angioedema, the patient underwent extensive evaluation for malignancy that was negative. Subsequently, immunoglobulin levels were found to be low – IgG 369 mg/dl, IgA 36, and IgM 30. Vaccine titers were also low. The patient had a remote history of pneumonia but no other significant infectious history. B-cell immunophenotyping and C1q/C1-INH autoantibody testing are underway.


Though it is well known certain autoimmune conditions can be the initial manifestation of CVID, we believe this is a rare report of autoimmune C1-INH deficiency as the presenting feature of CVID. Consideration of CVID may be warranted in patients who present with acquired angioedema without another cause.