Idiopathic mast cell activation syndrome is more often suspected than diagnosed-A prospective real-life study.

BACKGROUND: Idiopathic mast cell activation syndrome (MCAS) is characterized by three diagnostic criteria: (1) episodic mast cell (MC)-driven signs/symptoms of at least two organ systems in the absence of clonal MC expansion and definite triggers, (2) episodic increase in tryptase, and (3) response to MC-targeted treatment. Many patients believe they have MCAS, but how often this is the case remains unknown. METHODS: We prospectively investigated patients with suspected MCAS (n = 100) for the diagnostic criteria including baseline tryptase, KIT D816V mutation, and patient-reported outcome measures (PROMs) over the course of 12 weeks. Comorbid depression and anxiety were explored with the Hospital Anxiety and Depression Scale (HADS). RESULTS: In 53% of our patients (80% females), suspicion of MCAS was based on self-evaluation. In total, patients reported 87 different symptoms, mostly fatigue (n = 57), musculoskeletal pain/weakness (n = 49), and abdominal pain (n = 43), with overall high disease activity and impact. Two of 79 patients had increased tryptase (by >20% +2 ng/ml) following an episode. Only 5%, with any of the PROMs used, showed complete response to MC-targeted treatment. Depression and anxiety disorders were frequent comorbidities (n = 23 each), and 65 patients had pathological HADS values, which were linked to high disease impact and poor symptom control. CONCLUSION: Mast cell activation syndrome was confirmed in only 2% of patients, which implies that it is not MC activation that drives signs and symptoms in most patients with suspected MCAS. There is a high need for comprehensive research efforts aimed at the identification of the true underlying pathomechanism(s) in patients with suspected MCAS.

Development of the Cold Urticaria Activity Score.

BACKGROUND: Cold urticaria (ColdU) is a form of inducible urticaria where cold induces wheals and/or angioedema. The burden of disease is high and linked to trigger thresholds, exposure, and avoidance. There are presently no validated patient-reported outcome measures (PROMs) to assess and monitor disease activity. Our objective was to develop a disease-specific activity score for ColdU that is easy to administer and evaluate. METHODS: A Cold Urticaria Activity Score (ColdUAS) questionnaire was developed, directed by PROM developing guidelines. After the generation of a conceptional framework, the item generation phase included the literature research on ColdU signs and symptoms and on comparable tools for similar diseases and 47 ColdU patient interviews. Subsequently, an impact analysis for content validity was performed. The final selection of items underwent expert review for face validity and cognitive debriefing. RESULTS: The ColdUAS, a self-administered questionnaire for the prospective assessment of disease activity in patients with ColdU, consists of 4 items: 1. the frequency and severity of the signs (wheals and/or angioedema), 2. the frequency and severity of the symptoms (e.g., itch and burn), 3. the exposure to specific triggers, and 4. the avoidance of these triggers. The recall period for each item is the last 24 h. CONCLUSIONS: The ColdUAS is the first disease-specific PROM to assess ColdU disease activity. It may help to better assess patients' disease status in routine clinical practice as well as in clinical trials. Anchor-based approaches are currently used to validate the ColdUAS.

The real life experience goes on: update after 4 years on the first cohort treated with lanadelumab at our center.

Introduction: Lanadelumab is a first-line long-term prophylaxis (LTP) in hereditary angioedema (HAE). Real-life data on its long-term efficacy and safety are limited. It is unknown whether patients using lanadelumab need short-term prophylaxis (STP). Objectives: To provide 4-year follow-up data for our first 34 patients treating with lanadelumab. Methods: Patients were assessed for their current injection interval, attacks, treatment satisfaction, disease control (AECT), quality of life impairment (AE-QoL), events that can induce attacks, and the use of STP since the start of their treatment with lanadelumab. Results: Of 34 patients who started lanadelumab treatment, 32 were still using it after 4 years, with a median injection interval of 33 (range 14-90) days. HAE patients (n=28) reported longer intervals, i.e. 35 (14-90) days, than patients with angioedema due to acquired C1 inhibitor deficiency (n=4, 23 (14-31) days). With their current injection intervals, used for a mean duration of 29 ± 17 months, patients reported a yearly attack rate of 0.3 ± 0.1. More than 70% of patients were attack-free since starting their current injection interval. All patients reported well-controlled disease, i.e. ≥10 points in the AECT; 21 patients had complete control (16 points). AE-QoL scores improved further compared to our initial report, most prominently in the fears/shame domain (-6 points). Treatment satisfaction was very high. No angioedema occurred after 146 of 147 potentially attack-inducing medical procedures without STP. Conclusions: Our results demonstrate the long-term efficacy and safety of lanadelumab in real-life and question the need for STP in patients who use effective LTP.

Lanadelumab Efficacy, Safety, and Injection Interval Extension in HAE: A Real-Life Study.

BACKGROUND: Lanadelumab has been available in Germany for the prophylactic treatment of hereditary angioedema since February 2019. OBJECTIVE: To investigate real-life treatment outcome of lanadelumab and gain practical experience in adapting the therapy to individual patients. METHODS: The study included 34 patients. In 24 patients with hereditary angioedema and 4 patients with angioedema due to acquired C1-inhibitor deficiency, the previous treatment was switched to lanadelumab. In 6 patients with hereditary angioedema, lanadelumab from the open-label Hereditary Angioedema Long-term Prophylaxis study was continued in regular care. During the transition, patients were monitored using the angioedema control test and the angioedema quality of life questionnaire. At the time at which patients became symptom-free, the dosage interval was increased gradually (+3 days). RESULTS: On average, the angioedema control test values improved from 7.5 (poorly controlled disease) to 14.9 (well-controlled disease), and all patients showed adequate disease control. All treated patients, except 1 outlier, scored angioedema quality of life questionnaire values representing only a slight reduction in quality of life (mean, 14 points). At the time point of data collection, 9 patients used an average fixed injection interval of 30 days. Twenty-two patients were symptom-free from the beginning of the treatment phase and intended to extend their injection interval from 30 to 32.5 days (median). We recommended reducing the initial dosing interval from 24 to 21 days (median) to 3 patients because of intermediately occurring symptoms. CONCLUSIONS: Gradual extension of injection intervals of lanadelumab presented in this study can minimize the burden of therapy without losing efficacy.