Establishment of the deuterium oxide dilution method as a new possibility for determining the transendothelial water permeability.

Increase in transendothelial water permeability is an essential etiological factor in a variety of diseases like edema and shock. Despite the high clinical relevance, there has been no precise method to detect transendothelial water flow until now. The deuterium oxide (D2O) dilution method, already established for measuring transepithelial water transport, was used to precisely determine the transendothelial water permeability. It detected appropriate transendothelial water flow induced by different hydrostatic forces. This was shown in four different endothelial cell types. The general experimental setup was verified by gravimetry and absorbance spectroscopy. Determination of transendothelial electrical resistance (TEER) and immunocytochemical staining for proteins of the cell-cell contacts were performed to ensure that no damage to the endothelium occurred because of the measurements. Furthermore, endothelial barrier function was modulated. Measurement of transendothelial water flux was verified by measuring the TEER, the apparent permeability coefficient and the electrical capacity. The barrier-promoting substances cyclic adenosine monophosphate and iloprost reduced TEER and electrical capacity and increased permeability. This was accompanied by a reduced transendothelial water flux. In contrast, the barrier-damaging substances thrombin, histamine and bradykinin reduced TEER and electrical capacity, but increased permeability. Here, an increased water flow was shown. This newly established in vitro method for direct measurement of transendothelial water permeability was verified as a highly precise technique in various assays. The use of patient-specific endothelial cells enables individualized precision medicine in the context of basic edema research, for example regarding the development of barrier-protective pharmaceuticals.

A clinical evaluation of patients with known mutations (plasminogen and factor XII) with a focus on prophylactic treatment.

BACKGROUND: Hereditary angioedema with normal C1-inhibitor (HAE-nC1-INH) is a rare genetic disease. The symptoms can resemble other forms of hereditary angioedema (HAE), but the specific laboratory values are inconspicuous. The knowledge about treatment strategies in HAE-nC1-INH remains insufficient; most of the drugs are only licensed and approved for other types of HAE. METHODS: An analysis of all patients with HAE-nC1-INH was carried out in a certified angioedema treatment center in southern Germany. Only patients with a confirmed HAE-nC1-INH mutation were included. The impact of disease was monitored with validated questionnaires. RESULTS: Eighteen patients were included: two families with a factor XII mutation and seven families with a plasminogen mutation. All individuals received icatibant for on-demand therapy-efficient treatment response was reported. Three patients were severely affected, and prophylaxis was initiated with lanadelumab. According to the questionnaires, the clinical course and symptoms improved significantly under this prophylactic regime. CONCLUSION: This is one of the first descriptions of the clinical outcomes as a response to prophylactic treatment with lanadelumab in HAE-nC1-INH patients with a known mutation. The therapeutic management of HAE-1 and HAE-2 should also be the basis of HAE-nC1-INH, including prophylaxis.

A Retrospective Analysis of Long-Term Prophylaxis with Berotralstat in Patients with Hereditary Angioedema and Acquired C1-Inhibitor Deficiency-Real-World Data.

Hereditary angioedema (HAE) and acquired C1-inhibitor deficiency (AAE-C1-INH) are orphan diseases. Berotralstat is a recently licensed long-term prophylaxis (LTP) and the first oral therapy for HAE patients. No approved therapies exist for AAE-C1-INH patients. This study is the first to report real-world clinical data of patients with AAE-C1-INH and HAE who received Berotralstat. All patients treated with Berotralstat were included in this retrospective, bi-centric study. Data was collected from patients' attack calendars and the angioedema quality of life (AE-QoL) and angioedema control test (AECT) questionnaires before treatment, and at 3, 6, and 12 months after treatment and was then analyzed. Twelve patients were included, 3 patients with AAE-C1-INH, 7 patients with HAE type I, and 2 patients with HAE-nC1-INH. One patient (HAE I) quit treatment. Berotralstat was associated with fewer attacks in all groups. After 6 months of treatment, a median decrease of attacks per month was noted for HAE type I patients (3.3 to 1.5) and AAE-C1-INH patients (2.3 to 1.0). No aerodigestive attacks were noted for AAE-C1-INH patients. For HAE-nC1-INH patients, a mean decrease from 3.8 to 1.0 was noted (3 months). For HAE I patients, the total AE-QoL lowered a mean of 24.1 points after 6 months, for HAE-nC1-HAE patients 8.0 points, and for AAE-C1-INH patients 13.7 points. AECT scores increased for HAE I patients (mean: 7.1), HAE-nC1-INH patients (9.0), and AAE-C1-INH patients (4.2) after 6 months. Patients with HAE, HAE-nC1-INH, and AAE-C1-INH treated with Berotralstat showed reduced angioedema attacks and improved AE-QoL and AECT scores.

Acquired Angioedema Due to C1-Inhibitor Deficiency (AAE-C1-INH)-A Bicenter Retrospective Study on Diagnosis, Course, and Therapy.

BACKGROUND: Acquired angioedema with C1-inhibitor deficiency (AAE-C1-INH) is a rare condition resembling hereditary angioedema (HAE), but with late onset and low C1-inhibitor (C1-INH) due to consumption potentially caused by autoimmune diseases and mainly lymphatic malignancies. Being about 10-fold rarer than HAE, there is limited knowledge and no licensed therapy. OBJECTIVE: To report clinical and biological data from a newly described population of 20 patients with AAE-C1-INH assessing diagnostic delay, AAE-C1-INH:HAE-ratio, underlying conditions, and therapeutic management in Germany. METHODS: Retrospective data analysis of 20 patients from 2 angioedema centers in southern Germany. RESULTS: Median age at symptoms' onset was 64 years (60% females), with predominant swellings of the face (85%) and low levels for C1-INH in almost all patients. The ratio AAE-C1-INH:HAE was 1:9.7. From symptoms' onset to diagnosis of AAE-C1-INH, the median delay was 7.5 months, and between AAE-C1-INH symptoms' onset and diagnosis of the underlying hematological condition (n = 9) it was 4 months (median). Four patients had a history of solid neoplasm, 1 had a papillary thyroid carcinoma as the only potential cause for AAE-C1-INH, with treatment of the malignancy resulting in resolution of AAE-C1-INH. All the symptomatic patients were treated with off-label on-demand icatibant subcutaneously or C1-INH concentrate intravenously, and 6 severely affected patients needed off-label long-term prophylaxis with good symptom control. CONCLUSIONS: AAE-C1-INH is characterized by late-onset swellings mainly involving the face and low C1-INH levels. Diagnostic delay for AAE-C1-INH is further decreasing despite being about 10-fold rarer than HAE. Patients severely affected without underlying condition or no indication for treatment could benefit from off-label therapy.

Concomitant medication in patients with bradykinin-mediated angioedema - there's more than ACE inhibitors.

Bradykinin-mediated angioedema is a rare, non-allergic, potentially life-threatening disease. ACE inhibitor-induced angioedema and hereditary angioedema (HAE) are the two most common presentations. Therapeutic options, pathophysiology and diagnosis continue to be investigated, with considerable progress in HAE over the last few decades. For all patients with bradykinin-mediated angioedema, there are several medications that should be avoided or administered with caution. Some of the triggering medications are well known, while others are suspected or of unknown significance. A common denominator is that there is no approved therapy for bradykinin-mediated angioedema as a drug side effect. Some medications, such as tissue plasminogen activator, have a higher incidence of angioedema with potential airway compromise than ACE inhibitors, although this fact is widely underappreciated. In this review, we aim to summarize what is currently known and recommended about concomitant medication in HAE patients and the interaction of other bradykinin-influencing drugs.

[Functional disorders of the nose - definition, diagnostics and treatment options]. / Funktionelle Formstörungen der Nase ­ Definition, Diagnostik und Therapieoptionen.

The surgical spectrum of functional rhinosurgery includes nasal septum surgery, septorhinoplasty and nasal concha surgery. Based on the German guideline "Disorders of the inner and/or external nose (with functional and/or aesthetic impairment)" published in April 2022, which was prepared on behalf of the German Society of Otorhinolaryngology, Head and Neck Surgery, we discuss the indications, diagnostic approaches, the planning of the surgery and postoperative care. The most common findings of the external nose with a functional impairment include crooked nose, saddle nose, and tension nose. Combined pathologies occur. Well-documented in-depth consultation is essential for rhinosurgical procedures. In the case of revision surgery, the possible necessity of autologous ear or rib cartilage should be considered. Despite correct surgical performance, no "guarantee" can be given for the surgical (long-term) result in rhinosurgery.

New Year's Eve in otorhinolaryngology: a 16-year retrospective evaluation.

PURPOSE: Pyrotechnics are a long-standing tradition at the turn of the year. There are little data available on New Year's Eve-associated ORL injuries. Due to restrictions during the Corona pandemic, the handling of fireworks and meetings on New Year's Eve 2020-2022 had been significantly changed. Our aim was to analyze first data about New Year's Eve-associated ORL injuries. METHODS: A retrospective analysis of 16 turns of the year (2006-2022) at a University ORL department was performed. The 2 recent years were influenced by the changes and restrictions of the COVID-19 pandemic. RESULTS: Of 343 emergency presentations, 69 presented with New Year's Eve-associated reasons (20%). 72% were male, 15.9% were underage. 74% presented for fireworks-related injuries, 19% due to violent altercations. Noise trauma was present in 71%. The average number of New Year's Eve-associated emergency patients per year and the average total number of patients were reduced by more than half under COVID-19 pandemic conditions. CONCLUSIONS: New Year's Eve-associated ORL injuries range from inner ear trauma to midface fractures. Long-term damage may include hearing loss and tinnitus. These results shall support the responsible use of fireworks even after the end of the special regulations of the COVID-19 pandemic.

Efficacy of human C1 esterase inhibitor concentrate for treatment of ACE-inhibitor induced angioedema.

BACKGROUND: ACE inhibitor (ACEi) induced angioedema predominantly affects the upper aerodigestive tract. As ACEi induced angioedema is mediated by bradykinin, therapeutic response to antihistamines and glucocorticoids remains unsatisfactory. In bradykinin mediated hereditary angioedema, C1-esterase inhibitor (C1INH) is an effective and approved treatment since many years. Our aim was to evaluate the therapeutic effect of C1INH in ACEi induced angioedema. METHODS: We performed a double-blind, parallel-group, multicentre randomised placebo-controlled trial between December 2013 and September 2018. Eligible were adults with ACEi induced angioedema with airway obstruction. Participants were randomised 1:1 to single doses of either C1INH (20 IU/kg) or placebo (0.9% NaCl) i.v in addition to standard care (i.v. 500 mg prednisolone and 2.68 mg clemastine) i.v. Composite symptom scores were assessed at baseline and up to 48 h, at discharge and 1 week after discharge. Physician assessed time to complete oedema resolution (TCER) and time to onset of relief (TOR). RESULTS: 30 patients (16 C1INH, 14 placebo) were randomised and dosed. 25 (9 C1INH, 12 placebo) completed the study. TCER was 29.63 h ± 15.56 h in the C1INH and 17.29 h ± 10.40 h in the placebo arm (p = 0.0457). TORs were 4.13 h ± 3.38 h and 2.86 h ± 1.29 h for C1INH and placebo, respectively (p = 0.4443). There were no adverse events related to study medication. CONCLUSIONS: In the context of baseline application of steroids and antihistamines C1INH was inferior in the treatment of ACEi induced angioedema when compared to placebo with respect to time to complete resolution of symptoms. Eudra-CT Number: 2012-001670-28.

[Epistaxis Requiring Intervention After Swab for SARS-CoV-2]. / Interventionsbedürftige Epistaxis nasi nach SARS-CoV-2-Abstrich.

INTRODUCTION: Since May 2020, the first nasopharyngeal POC tests for SARS-CoV-2 diagnostic have been available. Due to the long passage through the nasal cavity, there is a risk of injury with subsequent epistaxis. METHODS: We describe the course of disease of two female patients who suffered from massive epistaxis requiring intervention after an externally performed nasopharyngeal swab. RESULTS: After nasal tamponade, one patient underwent clipping of the sphenopalatine artery under general anesthesia. The other patient suffered from nasal bleeding with hemorrhagic shock requiring transfusion. She was intubated and admitted to our hospital. CONCLUSION: The nasopharyngeal swab for diagnosis of SARS-CoV-2 can lead to life-threatening complications in rare cases. Considering that daily more than 5 million corona tests are being carried out worldwide as part of the current pandemic, complications should not be neglected. It is necessary that the person performing the swab has a detailed understanding of the anatomy involved. Alternative test methods were further assessed with regard to their sensitivity. With regard to the future need for SARS-CoV-2 tests, alternative and lower-risk test procedures must be investigated and established.

Etiology and predictors of cluster attacks of hereditary angioedema that recur despite pharmaceutical treatment.

Introduction: Hereditary angioedema (HAE) is a disease that leads to recurrent swelling of the skin and mucous membranes, including the upper airway tract. Apart from being deadly, these attacks can be debilitating, which leads to a poor quality of life in patients. Clinicians are occasionally confronted with patients who have recurrent attacks despite treatment with C1 esterase inhibitor concentrate or ß2-receptor antagonists. The goal of this study was to investigate repeated attacks that occur 48 hours to 7 days ("cluster attacks") after treatment, to determine why they occur and the factors that may be associated with them, and thus to prevent their occurrence. Methods: We conducted a multicenter mixed retrospective-prospective study with data acquired from all documented attacks in our patients with collective (n = 132) between 2015 and 2018. Results: Eighty-five percent (n = 132) of our total patient collective (N = 156) agreed to participate in the study. Nine percent of these patients (n = 12) had cluster attacks, with a total of 48 cluster attacks. The data procured from the patients were mixed retrospective-prospective. Approximately 72% of all the cluster attacks were caused by exogenous stimuli (41% due to psychological stress, 29% due to physical stimuli, and 2% due to menstruation). Cluster attacks occurred in 7% of the patients who received prophylactic therapy in comparison with 12.5% of patients who received on-demand therapy. Cluster attacks comprised 48.4% of all the attacks that patients with cluster-attacks (n= 9) experienced. In addition, the patients who were underdosing their C1 esterase inhibitor treatment had cluster attacks more often. A lower "time to repeated attack" was seen in the patients who received on-demand therapy compared with those who received prophylactic therapy. Discussion: The percentage of the patients who had attacks as a result of exogenous triggers was higher in the cluster-attack group (70.5%) compared with the general HAE population (30-42%). Repeated attacks, therefore, were strongly associated with external triggers. The patients who received prophylactic treatment and who experienced cluster attacks were highly likely to have been underdosing, which may explain the repeated attacks despite treatment. In the patients prone to cluster attacks, prophylaxis should be considered.

The Surgical Treatment of Peritonsillar Abscess: A Retrospective Analysis in 584 Patients.

OBJECTIVES: There are three surgical treatment options for patients with peritonsillar abscess (PTA): needle aspiration, incision and drainage (ID), and abscess tonsillectomy (ATE). The updated German national guideline (2015) included changes in the treatment of PTA. The indication for tonsillectomy (TE) in patients became more stringent and preference was given to ID in certain cases. STUDY DESIGN: Retrospective analysis. METHODS: We performed a retrospective systematic analysis of patient data using the in-house electronic patient records and considered a 4-year period from 2014 to 2017. About 584 patients were identified. Our aim was to analyze the influence of the updated guideline on clinical practice. RESULTS: 236 of 584 patients (40.4%) underwent ATE with contralateral TE. In 225 patients (38.5%), unilateral ATE was performed. Mean surgery time was significantly shortened when only unilateral ATE was performed. Concerning postoperative bleeding, we noted a tendency toward a lower incidence after ATE in comparison to ATE with contralateral TE. Less than 1% of patients who underwent ATE had to be revised surgically due to postoperative hemorrhage. After the revision of the guideline, unilateral ATE and ID were conducted more frequently. CONCLUSION: These results support that ATE in an inpatient setting is a considerably safe and effective primary therapeutic option. ID represents a favorable treatment option for patients with PTA and comorbidities, nevertheless, patient compliance is required and insufficient drainage or recurrence of PTA may occur. The revision of the guideline had a significant impact on the choice of interventions (P < .001), which is reflected by the increased number of unilateral ATE. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2706-2712, 2021.

Surgical tracheostomy in a cohort of COVID-19 patients.

BACKGROUND: One of the main symptoms of severe infection with the new coronavirus­2 (SARS-CoV-2) is hypoxemic respiratory failure because of viral pneumonia with the need for mechanical ventilation. Prolonged mechanical ventilation may require a tracheostomy, but the increased risk for contamination is a matter of considerable debate. OBJECTIVE: Evaluation of safety and effects of surgical tracheostomy on ventilation parameters and outcome in patients with COVID-19. STUDY DESIGN: Retrospective observational study between March 27 and May 18, 2020, in a single-center coronavirus disease-designated ICU at a tertiary care German hospital. PATIENTS: Patients with COVID-19 were treated with open surgical tracheostomy due to severe hypoxemic respiratory failure requiring mechanical ventilation. MEASUREMENTS: Clinical and ventilation data were obtained from medical records in a retrospective manner. RESULTS: A total of 18 patients with confirmed SARS-CoV­2 infection and surgical tracheostomy were analyzed. The age range was 42-87 years. All patients received open tracheostomy between 2-16 days after admission. Ventilation after tracheostomy was less invasive (reduction in PEAK and positive end-expiratory pressure [PEEP]) and lung compliance increased over time after tracheostomy. Also, sedative drugs could be reduced, and patients had a reduced need of norepinephrine to maintain hemodynamic stability. Six of 18 patients died. All surgical staff were equipped with N99-masks and facial shields or with powered air-purifying respirators (PAPR). CONCLUSION: Our data suggest that open surgical tracheostomy can be performed without severe complications in patients with COVID-19. Tracheostomy may reduce invasiveness of mechanical ventilation and the need for sedative drugs and norepinehprine. Recommendations for personal protective equipment (PPE) for surgical staff should be followed when PPE is available to avoid contamination of the personnel.

Prospective Analysis in Patients With HAE Under Prophylaxis With Lanadelumab: A Real-life Experience.

BACKGROUND AND OBJECTIVES: Patients with the rare disease hereditary angioedema (HAE) suffer from recurrent acute attacks of edema. There is no curative therapy, but the frequency of attacks and quality of life of severely affected patients can be improved by prophylactic therapy. The monoclonal antibody lanadelumab has been approved for routine prophylaxis in patients with HAE since November 2018. PATIENTS AND METHODS: In this prospective assessment, a long-term therapy with lanadelumab was initiated in 12 adult patients with HAE. We analyzed their course of disease 6 months after the start of long-term prophylactic therapy using a validated quality-of-life questionnaire and evaluated the frequency and severity of attacks as well as side effects. Furthermore, the therapy with lanadelumab was compared with the previous medication. RESULTS: To date, our study is the first prospective quality of life analysis in HAE patients under treatment with lanadelumab in real life conditions. Mean attack frequencies were reduced from 6.4 to 0.3 attacks per month and patient in our cohort (P<0.0001). No severe attacks occurred under lanadelumab prophylaxis. In all patients, quality of life increased significantly. CONCLUSIONS: Lanadelumab is an effective but expensive long-term prophylaxis for HAE patients. A favorable side-effect profile has been shown. J Drugs Dermatol. 2020;19(10):978-983. doi:10.36849/JDD.2020.5269.

[Surgery of the Nasal Septum]. / Chirurgie des Nasenseptums.

Dimension, position and stability of the cartilaginous nasal septum are crucial for successful surgery of the nasal septum. The objective of septoplasty is to create sufficient space in the anterior parts of the nose, particularly in the region of the nasal valves. Therefore, the cartilaginous nasal septum should obtain a state of "balanced tension". Essential steps of septoplasty include the hemitransfixion incision, the dissection of subperichondrial/subperiosteal tunnels, the mobilization via chondrotomy/osteotomy, the resection of cartilage/bone, the replantation of extracorporeally straightened material/reconstruction of the caudal nasal septum, closure by suture and fixation with nasal splints. Firmness of the caudal nasal septum is essential for sustainable septal surgery. It ensures the stability of the entire cartilaginous nose over decades.

Symptom Control of Patients With Chronic Rhinosinusitis With Nasal Polyps Under Maintenance Therapy With Daily Acetylsalicylic Acid.

INTRODUCTION: Nonsteroidal anti-inflammatory drugs (NSAID)-exacerbated respiratory disease (NERD) is defined by intolerance to cyclooxygenase 1 inhibitors, chronic rhinosinusitis with recurrent nasal polyps, and/or intrinsic bronchial asthma. Long-term administration of acetylsalicylic acid (ASA) after desensitization has been used to mitigate these sequelae, but the optimal dose and balancing symptom relief and side effects remain unsettled. METHODS: Retrospective data analysis of 85 patients with NERD receiving maintenance therapy of 300 mg ASA was followed by questionnaires (our own, not validated and the Sino-Nasal Outcome Test-20). We received responses from 55 patients and examined 30 of them clinically. RESULTS: Patients with no ASA-associated side effects were 56.4% (56 of 85 patients) of the cohort. In this study, 60% (33 of 55 patients) continued prophylaxis of 300 mg ASA daily for an average of 34.7 months. Elective surgery was the most frequent cause of discontinuation of ASA (21.8%; 12 of 55 patients). Rhinomanometry values were significantly improved with ASA (P < .05; Wilcoxon), but there was no significant reduction in nasal polyposis or improvement in olfaction at the time of follow-up examination. CONCLUSIONS: Minor clinical improvements were identified. Side effects were well tolerated by most patients, and no serious sequelae occurred. The indications for long-term ASA therapy in NERD patients remain unsettled.

Successful Long-Term Prophylactic Treatment With Subcutaneous C1 Esterase Inhibitor in a Patient With Hereditary Angioedema.

BACKGROUND: Hereditary angioedema (HAE) patients suffer from recurrent swellings. Current standard therapy consists of C1 esterase inhibitor (C1-INH) and bradykinin receptor B2 antagonists. Severe courses require prophylactic treatment. For such patients, it has been demonstrated that the intravenous (IV) administration of C1-INH [C1-INH(IV)] is safe and effective. A new prophylactic option is subcutaneous (SC) treatment with C1-INH. METHODS AND CASE: We present the case of an HAE patient placed on prophylactic C1-INH(IV) therapy due to frequent attacks when managed with on-demand therapy. An implanted port allowed the periodical and safe application of medication until the device was explanted due to an infection. Due to the poor venous access, repeated IV application failed. Therefore, we began a SC treatment with 1500 IU C1-INH [C1-INH(SC)] as long-term prophylaxis and analyzed the clinical course over 16 months. RESULTS: Under the SC prophylaxis, the number of attacks were reduced to 1/month in comparison to 4.33/month with no prophylactic treatment and 1.83/month with C1-INH(IV). No severe attacks and no attack within the upper airway occurred over the 16 months of C1-INH(SC) treatment. As a result, quality of life improved, as measured by the Angioedema quality of life questionaire (AE-QoL). CONCLUSION: Self-administered SC prophylactic use of C1-INH over a period of 16 months seems to be a well tolerated and efficient. The patient's quality of life improved, and by learning self-application, the patient gained independence.

Bradykinin signaling regulates solute permeability and cellular junction organization in lymphatic endothelial cells.

OBJECTIVE: Determine the effect of bradykinin on solute permeability and cellular junctional proteins in human dermis microvascular endothelial cells. METHODS: Cells were characterized by immunofluorescence and fluorescence-activated cell sorting. Macromolecular transport of dextran and albumin was monitored. Junctional protein expression and phosphorylation were determined by immunoblot analyses. Intracellular calcium and cAMP levels were evaluated. Target gene expression at mRNA and protein levels was determined. RESULTS: Human dermis microvascular endothelial cells comprised 97% lymphatic endothelial cells. Bradykinin increased the permeability to dextran in a concentration-dependent manner, while reduced the permeability to albumin. Bradykinin treatment down-regulated VE-cadherin expression and affected its phosphorylation status at Tyr731. It also down-regulated claudin-5 expression at the transcriptional level through bradykinin-2-receptor signaling. An increase in the intracellular calcium levels and a reduction in the cAMP concentration were associated effects. Finally, bradykinin induced the up-regulation of vascular endothelial growth factor-C protein which was found increased in BK-induced human dermis microvascular endothelial cells culture supernates. CONCLUSIONS: Human dermis microvascular endothelial cells represent a model of lymphatic endothelial cells, in which bradykinin-2-receptor is expressed. Bradykinin-induced bradykinin-2-receptor signaling through intracellular calcium mobilization and reduction in cAMP levels, triggered changes in solute permeability and cellular junction expression. It further up-regulated vascular endothelial growth factors-C protein expression, which is a key modulator of lymphatic vessels function and lymphangiogenesis.

Cyclooxygenase activity in bradykinin-induced dermal extravasation. A study in mice and humans.

BACKGROUND: Non-allergic angioedema is largely driven by increased plasma levels of bradykinin and over-activation of bradykinin receptor type II (B2), but the specific downstream signalling pathways remain unclear. The aim of this study was to identify signal transduction events involved in bradykinin-induced dermal extravasation. METHODS: Quantification of dermal extravasation was accomplished following intradermal (i.d.) injection of bradykinin or the B2 agonist labradimil in mice with endothelial NO-synthase (eNOS) deficiency and in C57BL/6J mice pre-treated with vehicle, NO-synthase or cyclooxygenase (COX) inhibitors. In the multicentre clinical study ABRASE, 38 healthy volunteers received i.d. bradykinin injections into the ventral forearm before and after oral treatment with the COX inhibitor ibuprofen (600 mg). The primary endpoint of ABRASE was the mean time to complete resolution of wheals (TTCR) and the secondary endpoint was the change of maximal wheal size. RESULTS: Neither NOS inhibitors nor eNOS deficiency altered bradykinin-induced extravasation. In striking contrast, the COX inhibitors ibuprofen, diclofenac, SC560 and celecoxib significantly diminished this extravasation when given before injection. As for diclofenac, a similar but significantly lower effect was observed when given after i.d. injection of bradykinin. Similar results were obtained when bradykinin was replaced by labradimil. In volunteers, ibuprofen significantly reduced TTCR (P < 0.001) and maximal wheal size (P = 0.0044). CONCLUSION: These data suggest that COX activity contributes to bradykinin-induced dermal extravasation in mice and humans. In addition, our findings may open new treatment options and point to a potential activity of drugs interfering with the release of the COX substrate arachidonic acid, e.g. glucocorticoids.

The Influence of ACE Inhibition on C1-Inhibitor: A Biomarker for ACE Inhibitor-Induced Angioedema?

AIMS: Angioedema is a rare side effect of angiotensin-converting enzyme (ACE) inhibitors. It remains unclear why it is only induced in a few patients taking ACE inhibitors, often after a long period of uneventful treatment. The aim of this study was to analyze the influence of ACE inhibitor treatment on C1-inhibitor (C1-INH) levels. METHODS: Captopril (5 mg/25 mg) was added to blood samples of 5 healthy subjects. C1-INH levels were measured before and after incubation for 180 min. The second section of the study was done with 17 patients who received therapy with an ACE inhibitor for the first time. C1-INH levels were measured before ACE inhibitor treatment, 24 h after first drug administration, and 4 weeks later. RESULTS: After incubation of blood samples with 5 mg captopril, there was no detectable change in C1-INH levels. After incubation with 25 mg, C1-INH activity was decreased by an average of 29% and the C1-INH concentration was decreased by an average of 0.06 g/L. In the second study section, inconsistent effects on C1-INH levels were detected. In the majority of patients, 24 h after the first ACE inhibitor administration C1-INH activity was tending to be increased. CONCLUSIONS: A dose-dependent effect on C1-INH levels in captopril-incubated blood samples of healthy test persons was shown. In patients with new ACE inhibitor treatment, heterogeneous reactions of C1-INH values were detected. Larger studies are needed over a longer period of time to find correlations between the effect of ACE inhibitor therapy on C1-INH levels and the clinical course/development of side effects.