Supplementary Material for: Elevated CEACAM5 Levels in Patients with Asthma

<b><i>Introduction:</i></b> Asthma is a common chronic respiratory disease. This study aimed to explore the expression level of carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) in induced sputum supernatant, induced sputum cells, and serum of asthma patients. <b><i>Methods:</i></b> The protein levels of CEACAM5 in induced sputum supernatant and serum were detected by enzyme-linked immunosorbent assay. The expression of CEACAM5 in induced sputum cells was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). We analyzed the correlations between CEACAM5 expression and the clinical characteristics (FeNO and IgE) of asthma. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic value of CEACAM5 in asthma. The expression level of CEACAM5 in 16HBE and BEAS-2B cells was detected by qRT-PCR. <b><i>Results:</i></b> The expression of CEACAM5 in induced sputum supernatant, induced sputum cells, and serum of asthma patients was significantly upregulated. Asthma patients with high CEACAM5 expression in induced sputum supernatant had higher levels of FeNO, IgE, and IL-13. The expression levels of CEACAM5 in induced sputum supernatant and induced sputum cells were positively correlated with FeNO and IgE. The ROC curve showed that CEACAM5 had a good diagnostic value in asthma. CEACAM5 expression was upregulated in BEAS-2B and 16HBE cells after IL-4 or IL-13 stimulation for 48 h. <b><i>Conclusion:</i></b> The expression levels of CEACAM5 in induced sputum supernatant, induced sputum cells, and serum of asthma patients were significantly increased. CEACAM5 may be involved in eosinophilic inflammation of asthma and may be used as a diagnostic biomarker and therapeutic target of asthma.