Elevated serum levels of periostin in patients with allergic bronchopulmonary aspergillosis

Summary Background Serum periostin levels have been reported to be an indicator of Th2 inflammation in asthmatic patients. Objective This study aimed to investigate serum levels of periostin in patients with allergic bronchopulmonary aspergillosis (ABPA) and to evaluate its diagnostic and monitoring value in the disease. Methods Patients with ABPA (n = 19) and asthma (n = 24), including severe asthma with fungal sensitisation (SAFS, n = 11) and severe asthma without fungal sensitization (SAwFS, n = 13), were enrolled. Serum levels of periostin were analysed by enzyme‐linked immunosorbent assay. Serum total IgE and Aspergillus fumigatus specific IgE, IgG were measured by ImmunoCAP. Levels of cytokines (IFN‐γ, IL‐4, IL‐5, IL‐8, IL‐10, IL‐13 and IL‐17A) were measured by Meso Scale Discovery (MSD). Results Serum levels of periostin in ABPA patients (85.55 ng/mL, [68.28‐166] ng/mL) were higher than those in SAFS (50.99 ng/mL, [32.02‐71.80] ng/mL; P < 0.01). Among the analysed cytokines, IL‐5 levels in ABPA (1.55 pg/mL, [0.96‐3.33] pg/mL) were higher than those in SAFS (0.31 pg/mL, [0.26‐0.56] pg/mL; P < 0.05) or SAwFS (0.34 pg/mL, [0.21‐0.56] pg/mL; P < 0.01). Serum periostin levels was positively associated with total IgE levels ( r = 0.319, P < 0.05), serum IL‐5 levels ( r = 0.484, P < 0.01) and blood eosinophil counts ( r = 0.428, P < 0.05). In ROC analysis, the clinical reference value of periostin was 68.8 ng/mL for differential diagnosis of ABPA and SAFS, with the area under the curve (AUC) of 0.81. Longitudinally, serum periostin levels did not change significantly after treatment in ABPA. Conclusions These findings suggested that serum levels of periostin were up‐regulated in ABPA patients, which may be associated with eosinophilic inflammation.