163 The Efficacy of Human Plasma-Derived C1-Inhibitor Concentrate Used for Prophylactic Treatment in Patients With Hereditary Angioedema Due to C1-Inhibitor Deficiency

BACKGROUND: Management of hereditary angioedema (HAE) comprises the prophylaxis and emergency treatment of edematous attacks. Our aim was to appraise the wide variety of the prophylactic use of plasma-derived human C1-inhibitor concentrate in HAE type I and type II patients. METHODS: 125 patients with HAE (54 males, 71 females) were included in our study. Classical short-term prophylaxis (STP) was administered before surgical or diagnostic interventions in the head and neck region and other types of major surgery, as well as before endotracheal intubation. Alternatively, STP was introduced before the expected and unavoidable onset of triggering factors. RESULTS: Before diagnosis of HAE, 128 interventions performed on 43 out of 125 patients induced edema: dental procedures (99 interventions in forty patients), ENT interventions (13/9 patients), surgery in the head and neck region (2/2 patients), surgery under general anesthesia (3/3 patients), gastroduodenoscopy (2/2 patients), delivery (6/6 patients) and artificial abortion (3/2 patients). After diagnosis of HAE, 500 IU of C1-INH concentrate was administered for STP, one hour before dental intervention (to 14 patients in 26 cases), surgery on the head or neck (to 7 patients in 7 cases), surgery under ETN (to 11 patients in 12 cases), diagnostic procedures (1 colonoscopy, 2 bronchoscopy, 4 gastroduodenoscopy, 1 cardiovascular catheterization), artificial abortion (to 4 patients in 6 cases), or childbirth (to 11 patients in 11 cases). Thirty-three of the 125 patients received prophylactic treatment on 70 occasions altogether. The medical history was positive for oedema provoked by medical interventions in 20 of the 33 patients undergoing STP with C1-INH concentrate. Eight patients received alternative prophylaxis: 2 patients during airway infections, 5 others before stressful life events, and one patient on the first day of the menstrual cycle over 4 months. In all cases, C1-INH concentrate prevented the occurrence of attacks. CONCLUSIONS: STP with C1-INH concentrate was effective in preventing angioedematous attacks in all cases. After interventions, during 48 hours observation period, edematous attacks did not occur. Repeated administration did not diminish its efficacy. C1-INH concentrate was well tolerated, and it was never associated with potentially treatment-related adverse effects.