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Type I hereditary angio-oedema. Variability of clinical presentation and course within two large kindreds.

OBJECTIVES: Hereditary angio-oedema (C1-inhibitor deficiency) is a disease with protean manifestations which is often misdiagnosed initially. The purpose of this study was to delineate the clinical spectrum and course of this potentially life-threatening disease. SETTING: Ten members of two unrelated affected kindreds were repeatedly hospitalized in our service with attacks of angio-oedema. Among the 271 members of the two kindreds 69 were identified who reported typical attacks. DESIGN AND SUBJECTS: Detailed information on the clinical course and laboratory data (C1-inhibitor concentration and activity, C4 concentration) were obtained from 59 of the 69 affected subjects. RESULTS: C1-inhibitor concentration and activity were low in all affected patients. The disease had become manifest by age 30 years in 98%. Most patients suffered from attacks of subcutaneous swellings and abdominal pain, and half of the patients have had attacks affecting the airways. The frequency of attacks ranged from less than one to over 26 per year. Forty-two per cent had to be hospitalized at least once. Four have died of acute airway obstruction. Thirty-eight attacks in 10 patients hospitalized in our service were all treated successfully with fresh frozen plasma or with C1-inhibitor concentrate. Trauma, stress, insect stings and foodstuff were triggering factors, but the majority of attacks occurred without an identifiable trigger. Oral contraceptives and pregnancy led to worsening of symptoms. Nonetheless, all 36 pregnancies reported were carried to term. Twenty-five patients were on continuous treatment with attenuated androgens or tranexamic acid, but only seven were free of attacks in the year preceding the survey. CONCLUSION: Hereditary angio-oedema is an autosomal dominant disease with great variability of clinical expression and severity, even within a single kindred. It often goes unrecognized over years, and it may lead to death if, in case of impending airway obstruction, specific therapy is not instituted.

Acute Disease↗

A randomized, controlled trial to study the efficacy and safety of C1 inhibitor concentrate in treating hereditary angioedema.

BACKGROUND: No effective treatment exists in the United States for acute attacks of hereditary angioedema (HAE). STUDY DESIGN AND METHODS: To evaluate the efficacy and safety of C1 inhibitor concentrate in treating HAE, a large primary care and referral center hospital conducted a randomized, placebo-controlled, double-blind trial with intent-to-treat analysis. Of the 36 patients enrolled in the study, 23 received treatment, and 22 completed the trial. C1 inhibitor concentrate or albumin (placebo) infusions were administered in a blind fashion to HAE patients who came to the hospital for treatment no later than 5 hours after an attack began. RESULTS: Relief was almost twice as fast in persons receiving C1 inhibitor concentrate than in the controls: 7.62 hours (mean; SD 7.08) versus 15.35 hours (mean; SD 8.31), respectively. The difference for time-to-relief was highly significant (p = 0.007, Mann-Whitney U test). The median time-to-relief was 6.17 hours (interquartile range 0.33-15.35) in the treatment group and 15.35 hours (interquartile range 14.00-22.83) in the control group. Resolution of symptoms was one-third faster in the C1 inhibitor concentrate group than in the placebo group: 23.98 hours (mean; SD 14.81) and 34.58 hours (mean; SD 13.56), respectively (p = 0.09, Mann-Whitney U test). Recovery of functional C1 inhibitor was 119.65 percent (mean; SD 50.80), and half-life was 37.87 hours (mean; SD 19.75). Recovery of antigenic C1 inhibitor was 147.75 percent (mean; SD 97.68), and half-life was 24.01 hours (mean; SD 9.70). There were no viral infections or serious adverse effects from the drug after 70 attacks in the treatment group and 96 attacks in the control group. CONCLUSIONS: C1 inhibitor concentrate is a safe, effective treatment for acute attacks of HAE.

Acute Disease↗

Effect of C1-esterase-inhibitor on capillary leak and inflammatory response syndrome during arterial switch operations in neonates.

OBJECTIVE: To determine if prophylactic administration of C1-esterase-inhibitor would have a beneficial effect on postoperative weight gain and the inflammatory response in neonates undergoing cardiac surgery with cardiopulmonary bypass (CPB). DESIGN: Randomized, double-blinded study. SETTING: University-affiliated heart center. PARTICIPANTS: Twenty-four neonates with transposition of the great arteries. INTERVENTIONS: In group inhibitor (INH) patients (n = 12), 100 IU/kg of C1-esterase-inhibitor (Berinert) was given 30 minutes before CPB. In group placebo (P) patients (n = 12), placebo was administered instead. Interleukin (IL)-6, C3a anaphylatoxin, C1 activity, prekallikrein, Hageman factor, D-dimers, and clinical parameters were measured 6 times perioperatively. MEASUREMENTS AND MAIN RESULTS: All 24 patients had an uneventful clinical course. Mean arterial pressure and pulmonary oxygenation after CPB were superior in group INH patients. The weight gain on postoperative days 1 to 4 was significantly less in group INH patients compared with group P (55 +/- 59 g vs. 340 +/- 121 g, day 1). The concentration of IL-6 (76 +/- 17 pg/mL vs. 262 +/- 95 pg/mL during CPB) was significantly lower in group INH patients compared with group P patients. In contrast, no influence on C3a anaphylatoxin and coagulation factors was found. CONCLUSION: Prophylactic application of C1-esterase-inhibitor in neonates undergoing arterial switch operations produces less inflammatory response compared with placebo. This difference may have contributed to improved clinical parameters, including less weight gain postoperatively.

Capillary Leak Syndrome↗

Hereditary angioedema with gastrointestinal involvement: endoscopic appearance.

We present the first reported case of hereditary angioedema (HAE) with gastric involvement to be successfully evaluated by endoscopy both during and after an attack. A 31-year-old man who had a family history of angioedema was admitted to our hospital with complaints of abdominal pain and swelling of extremities. Computed tomography scan and endoscopy carried out during this attack revealed transient gastrointestinal wall edema which, along with decreased levels of serum C4 and C1 inhibitor, confirmed the diagnosis of HAE with gastrointestinal involvement. During the attack, the gastric mucosa was erythematous and edematous, and parts of its surface bulged into the gastric lumen, resembling a submucosal tumor, as a result of massive submucosal edema. During the healing process, a number of small nodules and raised erosions developed over the entire gastric mucosal surface after healing of prominent gastric edema. Within 55 days, the gastric mucosa had returned to normal. The endoscopic findings for the stomach in HAE have not, to our knowledge, been previously described.

Adult↗

[Hereditary angioedema. A rare cause of acute abdominal pain with ascites].

HISTORY AND CLINICAL FINDINGS: Since the age of 16 years a now 25-year-old woman had been known to have C1-inhibitor (C1-INH) deficiency. She presented herself at the emergency department because of acute severe lower abdominal cramps. A urinary infection had been treated with antibiotics for the previous 4 days. There was marked pain on pressure over the lower abdomen, but there were no signs of peritonitis and bowel sound were normal. There had been no nausea or vomiting and the stools had been normal. INVESTIGATIONS: There was a leukocytosis of 10,200/microliter, moderately elevated C-reactive protein (44.8 mg/l), haemoglobin concentration of 17 g/dl and haematocrit of 51%. Radiology revealed oedema of the duodenum and sonography showed free fluid in the abdomen. TREATMENT AND COURSE: After excluding an acute abdomen and in view of the C1-INH deficiency treatment was symptomatic. All symptoms completely disappeared after 2 days. CONCLUSIONS: Exclusively gastrointestinal symptoms and ascites are rare in patients with hereditary angioedema. But knowledge of this manifestation of the disease is important because patients are sometimes operated under the false diagnosis of acute abdomen. In severe cases symptomatic treatment may have to be supplemented by C1-INH administration. Prevention with attenuated androgens should be started or modified, respectively.

Abdominal Pain↗

[Ascites and suspected acute abdomen in hereditary angioedema due to C1 inhibitor deficiency].

HISTORY AND CLINICAL FINDINGS: A 35-year-old man, for 8 years known to have hereditary angio-oedema with recurrent cutaneous swellings and occasional attacks of gastrointestinal pain, developed very painful, colic-like upper abdominal symptoms and frequent vomiting. INVESTIGATIONS: Routine laboratory tests were normal, except for leucocytosis of 18,200 WBC/microliter. The plasma concentrations of C1-esterase inhibitor (5.6 mg/dl) and of complement factor C4 (10.0 mg/dl) were reduced. Computed tomography revealed about 500 ml free fluid, a perihepatic effusion and definite oedematous thickening of the ileal wall. TREATMENT AND COURSE: During conservative treatment with infusions and no food by mouth the symptoms regressed. Abdominal ultrasonography was normal (no free intraabdominal fluid). Since discharge (now more than 15 months ago) the patient has been on danazole medication (200 mg/d). CONCLUSION: Recurrent gastrointestinal colics are typical of for hereditary angio-oedema and can imitate an acute abdomen. Concurrent ascites has only recently been described. Appropriate instruction of the patient and his/her medical practitioner is important to avoid unnecessary laparotomy.

Abdomen, Acute↗

[Complement activation after the intravascular administration of contrast media: a comparison between ionic and nonionic x-ray contrast media].

The effects of intravascular radiographic contrast media on the complement system were investigated in 46 patients. An ionic (sodium-/meglumine amidotrizoate, n = 22) or a non-ionic (iohexol, n = 24) contrast agent was applied for an i.v. urography. The levels of the complement-compounds C1q, C3, C5 and of the C1 inhibitor were determined at the end of the infusion and 20 minutes later. In both groups we obtained a significant (p less than 0.01) decrease of C3 during infusion for 10 to 15%. 20 minutes later these values were almost normalized again. Infusion of iohexol additionally caused a marked consumption of C5 and C1q (reduction to 85%), while the ionic contrast agent had no significant effect on these components. Both contrast media caused a decrease of the C1-inhibitor levels. Our results demonstrate an activation of the complement system by i.v. application of radiographic contrast media. The decrease of the C1q-level due to infusion of iohexol indicates an additional involvement of the classical activation pathway of the complement cascade.

Complement Activating Enzymes↗

[Hereditary angioedema type II with predominantly abdominal symptoms].

For two years a 19-year-old patient had been complaining of recurrent abdominal symptoms consisting of severe colicky pain, nausea, vomiting and diarrhoea. Occasionally he noticed concomitant subcutaneous swellings in the limbs. There were no swellings in the face or the region of the upper airway. The symptoms occurred once or twice a month, spontaneously receding within 3-4 days. These signs and symptoms indicated hereditary angio-oedema. Serum concentration of C1-esterase inhibitor was normal (13 mg/dl), but its serum activity was reduced to 16% (normal range 80-125%). This is thus a case of type II C1-esterase inhibitor deficiency. Since starting low-dosage treatment with Danazol (initially, for two months, 200 mg daily, then 200 mg five times per week) the patient has been symptom-free.

Adult↗

[Immunocytoma with acquired C1-esterase inhibitor deficiency and recurrent angioneurotic edema].

Four attacks of mucosal angioneurotic oedema occurred in a 57-year-old woman, requiring tracheotomy for one episode. Decreased or non-measurable levels of complement components C1q, C-1-INH and C4 pointed to a complement consumption. The basic disease was a pleomorphic immunocytoma with the production of monoclonal IgM. Treatment with danazol, 600 mg daily, raised the serum level of C-1-INH, but not of C4.

Angioedema↗

Treatment of hereditary angioedema with danazol. Reversal of clinical and biochemical abnormalities.

Danazol, an androgen derivative, was evaluated for its effectiveness in preventing attacks of hereditary angioedema in a double-blind study with nine patients. Of 47 placebo courses, 44 ended with attacks, but during 46 danazol courses only one attack occurred. Side effects were minimal, and virilization was not observed in the women studied. C1 esterase inhibitor levels increased three to four times, and levels of the fourth component of complement (C4) increased 15 times. These changes began during the first day of therapy and were maximal by one to two weeks. After therapy was stopped, C1 esterase inhibitor and C4 levels rapidly decreased. Danazol effectively prevents attacks in hereditary angioedema and acts to correct the underlying biochemical abnormality.

Adult↗

C1r-C1s-C1inhibitor (C1rs-C1inh) complex measurements in tears of patients before and after penetrating keratoplasty.

PURPOSE: The aim of this pilot study was to determine the presence of complement activation products in tears from pre- and postkeratoplasty eyes and the fellow eyes in order to investigate the activation of the classical and alternative pathways of the complement system in the early postkeratoplasty period. METHODS: Tear samples from both eyes of 19 prekeratoplasty patients were tested. From 10 patients, samples were taken before operation, one week and 3 weeks after penetrating keratoplasty. Only baseline and 1 weak samples, and baseline and 3 week samples were available from 5 and 2 patients, respectively, while only baseline tear samples were collected from 2 patients. Tear concentration of two complement activation products, C1rs-C1inh and C3bBbP were determined by enzyme-linked immunosorbent assay. RESULTS: There was no difference (p = 0.339) between baseline samples of the eyes waiting for operation (0.93 +/- 0.51 AU/ml, mean +/- SEM) and the fellow eyes (0.33 +/- 0.33 AU/ml) in respect of mean C1rs-C1inh complex concentration. The one-week samples of the operated eyes revealed significantly (p = 0.006) elevated levels of C1rs-C1inh complexes (18.8. +/- 6.37 AU/ml), compared to their baseline samples (1.18 +/- 0.64 AU/ml), whereas the one-week values of the fellow eyes did not differ from the baseline values. Compared to the increased one-week values, the three-week values decreased to the baseline values in the operated eyes. C3bBbP could be detected in 3/68 tear samples. CONCLUSIONS: In our study we demonstrated the increased concentration of C1rs-C1inh complex in several tear samples taken early after human penetrating keratoplasty. These findings provide direct evidence that the classical pathway of complement may be activated in the early postoperative period after penetrating keratoplasty.

Adult↗

Angiooedema due to acquired deficiency of C1-esterase inhibitor associated with leucocytoclastic vasculitis.

A hereditary and an acquired type of C1-esterase inhibitor deficiency have been described. Manifestations characteristic of both forms include recurrent subcutaneous and submucosal angiooedema. Acquired C1-esterase inhibitor deficiency has been observed in association with lymphoproliferative disorders, malignancy, autoimmune diseases and infections. We report on a case with the acquired form of the disease accompanied by leucocytoclastic vasculitis. Treatment with antimalarial agents resulted in complete resolution of symptoms and signs. Furthermore, C1-esterase inhibitor concentration and activity, as well as C1 levels, all returned to normal.

Adult↗

Screening of concentrations of C-reactive protein and various plasma protease inhibitors preoperatively for the prediction of postoperative complications.

OBJECTIVE: To find out whether concentrations of albumin (reflecting nutritional state), C-reactive protein (reflecting an acute phase reaction) or plasma protease inhibitors (reflecting ongoing proteolysis) are good predictors of postoperative complications, and whether other biochemical tests may improve diagnostic accuracy. DESIGN: Retrospective study. SETTING: University hospital, Sweden. SUBJECTS: 260 patients undergoing elective surgery for malignant (n = 149) or benign (n = 111) disease. MAIN OUTCOME MEASURES: Preoperative biochemical plasma measurements and postoperative complications. RESULTS: 192 patients recovered uneventfully and 35 had minor and 33 major postoperative complications. An increased plasma C-reactive protein concentration preoperatively, as well as a reduced albumin concentration, predicted the risk of developing major postoperative complications. Measurement of plasma protease inhibitors (C1-esterase inhibitor, alpha-2-macroglobulin and antithrombin III), specific biochemical studies of microheterogeneity, or comparison of quantitative and functional concentrations of the inhibitors gave no additional information. CONCLUSION: One measurement of the C-reactive protein and albumin concentrations preoperatively will identify patients at risk of developing severe postoperative complications.

Adult↗

Complement 1 inhibitor is a regulator of the alternative complement pathway.

We studied complement 1 inhibitor (C1-INH) as an inhibitor of the alternative complement pathway. C1-INH prevented lysis, induced by the alternative complement pathway, of paroxysmal nocturnal hemoglobinuria (PNH) erythrocytes in human serum. It inhibited the binding of both factors B and C3 to PNH and rabbit erythrocytes and blocked the ability of factor B to restore alternative-pathway function in factor B-depleted serum. C1-INH did not bind to factors B or D but did bind to immobilized C3b and cobra venom factor (CVF), a C3b analogue. C1-INH prevented factor B from binding to CVF-coated beads and dissociated bound factor B from such beads. Factor B and C1-INH showed cross competition in binding to CVF-coated beads. Factor D cleaved factor B into Bb and Ba in the presence of C3b. Cleavage was markedly inhibited when C3b was preincubated with C1-INH. C1-INH inhibited the formation of CVFBb and decreased the C3 cleavage. Removal of C1-INH from serum, in the presence of Mg-EGTA with an anti-C1-INH immunoabsorbant, markedly increased alternative-pathway lysis. C1-INH interacts with C3b to inhibit binding of factor B to C3b. At physiologic concentrations, it is a downregulator of the alternative pathway convertase.

Absorption↗

Potentiation of C1 esterase inhibitor by StcE, a metalloprotease secreted by Escherichia coli O157:H7.

The complement system is an essential component of host defense against pathogens. Previous research in our laboratory identified StcE, a metalloprotease secreted by Escherichia coli O157:H7 that cleaves the serpin C1 esterase inhibitor (C1-INH), a major regulator of the classical complement cascade. Analyses of StcE-treated C1-INH activity revealed that surprisingly, StcE enhanced the ability of C1-INH to inhibit the classical complement-mediated lysis of sheep erythrocytes. StcE directly interacts with both cells and C1-INH, thereby binding C1-INH to the cell surface. This suggests that the augmented activity of StcE-treated C1-INH is due to the increased concentration of C1-INH at the sites of potential lytic complex formation. Indeed, removal of StcE abolishes the ability of C1-INH to bind erythrocyte surfaces, whereas the proteolysis of C1-INH is unnecessary to potentiate its inhibitory activity. Physical analyses showed that StcE interacts with C1-INH within its aminoterminal domain, allowing the unaffected serpin domain to interact with its targets. In addition, StcE-treated C1-INH provides significantly increased serum resistance to E. coli K-12 over native C1-INH. These data suggest that by recruiting C1-INH to cell surfaces, StcE may protect both E. coli O157:H7 and the host cells to which the bacterium adheres from complement-mediated lysis and potentially damaging inflammatory events.

Animals↗