Disease modification in chronic spontaneous urticaria.

Chronic spontaneous urticaria (CSU) is a debilitating, inflammatory skin condition characterized by infiltrating immune cells. Available treatments are limited to improving the signs and symptoms. There is an unmet need to develop therapies that target disease-driving pathways upstream of mast cell activation to inhibit or delay the progression of CSU and associated comorbidities. Here, we aim to define disease modification due to a treatment intervention and criteria that disease-modifying treatments (DMTs) must meet in CSU. We have defined disease modification in CSU as a favorable treatment-induced change in the underlying pathophysiology and, therefore, the disease course, which is clinically beneficial and enduring. A DMT must fulfil the following criteria: (1) prevents or delays the progression of CSU, (2) induces long-term, therapy-free clinical remission, which is the sustained absence of CSU signs and symptoms without the need for treatment, and (3) affects the underlying mechanism of CSU, as demonstrated by an effect on disease-driving signals and/or a biomarker. DMTs in CSU should slow disease progression, achieve long-lasting disease remission, target disease-driving mechanisms, reduce mast cell-activating IgE autoantibodies, target cytokine profile polarization, and normalize the gut microbiome and barrier. Treating CSU at the immune system level could provide valuable alternatives to pharmacotherapy in CSU management. Specific DMTs in CSU are yet to be developed, but some show potential benefits, such as inhibitors of Bruton's Tyrosine Kinase, IL-4 and IL-13. Future therapies could prevent CSU signs and symptoms, achieve long-term clinical benefits after discontinuing treatment, and prevent associated concomitant disorders.

Positive Basophil Tests Are Linked to High Disease Activity and Other Features of Autoimmune Chronic Spontaneous Urticaria: A Systematic Review.

BACKGROUND: Chronic spontaneous urticaria (CSU) is believed to be Autoimmune (aiCSU) (type IIb CSU) in at least 8% of patients, associated with mast cell-activating IgG autoantibodies. Basophil tests such as the basophil activation test (BAT) and basophil histamine release assay (BHRA) are considered the best single tests for an aiCSU diagnosis. To date, the strength of associations among a positive BAT and/or BHRA (BAT/BHRA+) and CSU features, patient demographics, and response to treatment remains poorly characterized. OBJECTIVE: To evaluate the strength of current evidence on basophil tests as parameters for CSU characteristics. METHODS: We performed a systematic literature search and review to assess the relationship between BAT/BHRA+ and clinical and laboratory parameters of CSU. Of 1,058 records found in the search, 94 studies were reviewed by experts in urticaria and 42 were included in the analysis. RESULTS: In CSU patients, BAT/BHRA+ showed a strong level of evidence for an association with high disease activity and low levels of total IgE. A weak level of evidence was shown for the association of BAT/BHRA+ and the presence of angioedema, and basopenia. CONCLUSIONS: Our results suggest that aiCSU defined by BAT/BHRA+ is more active or severe and is linked to other aiCSU markers such as low total IgE/basopenia. Basophil tests should be standardized and implemented in routine clinical care to improve the diagnosis and treatment of patients with aiCSU.

Evidence for histamine release in chronic inducible urticaria - A systematic review.

Background: Chronic inducible urticaria (CIndU) constitutes a group of nine different CIndUs in which pruritic wheals and/or angioedema occur after exposure to specific and definite triggers. Histamine released from activated and degranulating skin mast cells is held to play a key role in the pathogenesis of CIndU, but evidence to support this has, as of yet, not been reviewed systematically or in detail. We aim to characterize the role and relevance of histamine in CIndU. Methods: We systematically searched 3 electronic databases (PubMed, Scopus, and Embase) for studies that reported increased serum or skin histamine concentration (direct evidence) or in vitro or ex vivo histamine release (indirect evidence) following trigger exposure. Results: An initial total of 3,882 articles was narrowed down to 107 relevant studies of which 52 were in cold urticaria, 19 in cholinergic urticaria, 14 in heat urticaria, 10 in contact urticaria, 7 each in solar urticaria and vibratory angioedema, 4 each in symptomatic dermographism and aquagenic urticaria, and 3 in delayed pressure urticaria. The results of our review support that histamine has a key pathogenic role in the pathogenesis of all CIndUs, but it is not the sole mediator as evidenced by the often poor relationship between the level of histamine and severity of symptoms and the variable clinical efficacy of H1-antihistamines. Conclusions: Histamine released from skin mast cells is a key driver of the development of signs and symptoms and a promising therapeutic target in CIndU.

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.