Distribution characteristics of cow’s milk-sIgE components in children with respiratory allergic diseases in southern China

Background Cow’s milk (CM) is the main food allergen for toddlers and infants. Presently, studies on CM specific immunoglobulin E (sIgE) sensitization and positive distribution of CM components ALA-, CAS-, and BLG-sIgE are lacking in infants with respiratory allergic diseases, especially in southern China. This study therefore aimed to investigate the distribution of CM sensitization and the relation between its components α-lactalbumin (ALA), β-lactoglobulin (BLG) and casein (CAS) sIgE in children with respiratory allergic diseases in southern China. Methods A total of 1839 children (≤12 years) with respiratory diseases and detected CM-sIgE levels were included. Serum samples were collected from the Respiratory Diseases Bioresources Center of the National Center for Respiratory Diseases in southern China from August 2012 to July 2017. ALA-, BLG-, and CAS-sIgE were detected and questionnaires were completed in 103 children. Results A total of 36.7% children were positive for CM-sIgE. CM-sIgE levels were higher in asthmatic bronchitis (AB) group than in other allergic respiratory disease groups (all P rs = 0.833), ALA-sIgE (rs = 0.816), and CAS-sIgE (rs = 0.573) levels (all p < 0.001). Conclusions In southern China, CM-sIgE levels were higher in children with AB than in those with other respiratory allergic diseases. ALA and BLG were the main allergenic components detected in CM-sIgE-sensitized children with respiratory allergic diseases.