https://www.selleckchem.com/products/Pitavastatin-calcium(Livalo).html These findings about specialist perception of diagnosis and treatment of severe asthma will inform the use of emerging new drugs and facilitate personalized therapy.Mas-related G-protein coupled receptor-X2 (MRGPRX2), a receptor on mast cells, basophils, and eosinophils associated with immunoglobulin E (IgE)-independent degranulation, has been reported to be highly expressed on cutaneous mast cells in patients with severe chronic spontaneous urticaria (CSU). We sought to investigate whether MRGPRX2 levels in the sera from CSU patients differ from those in healthy control subjects and to evaluate the clinical utility of MRGPRX2 levels in CSU patients. Severe CSU was defined as urticaria activity score over 7 days (UAS7) ≥ 28. Serum samples from 116 (73 severe and 43 non-severe) CSU patients and 50 healthy subjects were screened for MRGPRX2 using enzyme-linked immunosorbent assay. Serum MRGPRX2 levels were significantly higher in patients with severe CSU (median [interquartile range], 16.5 [10.8-24.8]) than in healthy controls (11.7 [6.5-21.2], P = 0.036) and in non-severe CSU patients (8.7 [4.5-18.8], P = 0.002), although they did not differ between healthy subjects and non-severe CSU patients. Serum MRGPRX2 levels in CSU patients showed positive correlations with UAS7 and specific IgE against Dermatophagoides farinae in CSU subjects, whereas no correlations were observed for age, sex, urticaria duration, atopy, combined angioedema, autologous serum skin test positivity, or total IgE levels. Logistic regression analysis identified serum MRGPRX2 ≥ 12 ng/mL (odds ratio, 6.421; P = 0.002) as an independent risk factor for severe CSU, along with increased serum total IgE levels, peripheral basophil percentage, and angioedema. In conclusion, we suggest that serum MRGPRX2 could help indicate severe CSU. Macrophages are important regulators of environmental allergen-induced airway inflammation and asthma