C1 Esterase Inhibitor Deficiency Dr. C. Kalicinsky Allergy and Clinical Immunology

Objectives List the symptoms of C1 esterase inhibitor deficiency. Contrast management of C1 esterase inhibitor deficiency with other forms of angioedema. Become familiar with the use of C1 esterase inhibitor concentrate.

C1 esterase inhibitor Protein, which in its active form prevents fluid from leaving blood vessels, thereby preventing tissue swelling. This type of swelling is called angioedema.

Lip swelling Tongue swelling Tongue swelling causing obstruction of the airway

C1 Esterase Inhibitor Deficiency Hereditary (HAE) Acquired (AAE) - malignancy, especially hematologic - connective tissue disease Diagnosed by measuring c1 esterase inhibitor level (Type 1) and function (Type 2) Occasionally, the level and function are normal (Type 3) Angioedema without urticaria Can be fatal due to asphyxiation Gut involvement causes severe abdominal pain

Management Epinephrine, antihistamine and corticosteroid NOT effective Airway management Once diagnosed, patients are given letter or wallet card explaining their condition and treatment to present to ER.

C1 Esterase Inhibitor Concentrate (Berinert P) Blood product, therefore blood product request form to be faxed to blood bank. Some WRHA and rural hospital blood banks have a list of patients requiring this product and may keep a supply available. WRHA monograph in final stages of approval and will be posted on Blood Manitoba website by Feb 2016. Allergy on call needs to authorize release from local bloodbank.

DOSAGE: Usual: 20 units /kg IV by slow IV injection (this is stated in product insert) Maximum single dose:1500 units (the maximum single dose may be increased beyond 1500 units if authorized by an immunologist)

May repeat dose of 500-1000 units if condition does not improve in 1-2 hours. Side effects: headache, abdominal pain, nausea, muscle spasm, pain, diarrhea, vomiting. Anaphylaxis rare.

If abdominal pain does not improve, another diagnosis should be considered.