Identification of rBlo t 41 with a chitin-binding type-2 domain: A novel major allergen from Blomia tropicalis.

BACKGROUND: Blomia tropicalis (B. tropicalis) has been reported to impose an increased risk of allergic diseases. However, few characteristics of the unknown allergen components responsible for B. tropicalis allergy and clinical relevance have been fully identified. METHODS: We synthesized and characterized the physicochemical properties and cross-reactivity of the newly discovered recombinant B. tropicalis group 41 allergen (rBlo t 41). Subsequently, sera were collected from 107 B. tropicalis allergic subjects to evaluate the prevalence of the rBlo t 41. Lastly, its allergenicity was tested in humans by basophil activation assays, and in mice by a model of allergic asthma. RESULTS: The mature protein of rBlo t 41 was described as 104 amino acids long and 15.8 kDa, and its limited cross-reactivity was observed between allergens of house dust mites (HDM). Sensitization rate of rBlo t 41 (56.07 %) was lower than rBlo t 2 (76.29 %) and rBlo t 5 (69.07 %) in our study. Besides, rBlo t 41 elicited CD63 upregulation in basophils, whereas rBlo t 41-sensitized mice generated rBlo t 41-IgE and developed allergic airway inflammation after allergen exposure. Of note, component-based tests showed a high area under curve value (AUC = 0.75) of rBlo t 41, displaying its favorable diagnostic potential in B. tropicalis allergy. CONCLUSIONS: rBlo t 41 was identified as a candidate novel major allergen with good diagnostic potential in B. tropicalis sensitization. Additionally, we provided strong evidence about rBlo t 41 on the clinically relevant manifestations in B. tropicalis allergies, conducive to facilitating the development of component-resolved diagnosis.

Patterns of aeroallergen sensitization in asthma patients identified by latent class analysis: A cross-sectional study in China.

BACKGROUND: This cross-sectional study aimed to identify latent sensitization profiles of asthma patients in mainland China, unveiling the association between regional differences and sensitization patterns. METHODS: 1056 asthma participants from 10 medical centers divided into eastern and western cohorts were clustered into four individual sensitization patterns, respectively, by using an unsupervised statistical modeling method, latent class analysis (LCA), based on the levels of 12 aeroallergens specific IgE reactivities. Moreover, differences in clinical characteristics and environmental exposures were compared in different sensitization patterns. RESULTS: Four distinct sensitization patterns in the two cohorts were defined as follows, respectively. Eastern cohort: Class 1: "High weed pollen and house dust mites (HDMs) sensitization" (8.87%), Class 2: "HDMs dominated sensitization" (38.38%), Class 3: "High HDMs and animal dander sensitization" (6.95%), Class 4: "Low/no aeroallergen sensitization" (45.80%). Western cohort: Class 1: "High weed pollen sensitization" (26.14%), Class 2: "High multi-pollen sensitization" (15.02%), Class 3: "HDMs-dominated sensitization" (10.33%), Class 4: "Low/no aeroallergen sensitization" (48.51%). Of note, the significant statistical difference in age, asthma control test score (ACT) and comorbidities were observed within or between different sensitization patterns. Exposure factors in different sensitization patterns were pointed out. CONCLUSIONS: Asthmatic patients with distinct sensitization patterns were clustered and identified through the LCA method, disclosing the relationship between sensitization profiles of multiple aeroallergens and geographical differences, providing novel insights and potential strategies for atopic disease monitoring, management and prevention in clinical practice.