Detecting gene expression in buccal mucosa in subjects with asthma versus subjects without asthma

Background Differences in mRNA expression for inflammatory markers have been observed between subjects with asthma vs. controls and in relation to corticosteroid response. However, these studies utilized methods (e.g., bronchoscopy) that are too invasive to be used routinely in children and in the clinic. The primary purpose of this study was to determine the feasibility of obtaining RNA of adequate quantity and quality from buccal mucosa of children and adults for gene expression studies. Secondly, this study aimed to determine whether gene expression patterns in buccal mucosa are similar to those that have been observed in respiratory epithelium. Methods We enrolled 94 subjects with and without asthma between 5 and 54years of age. Relative gene expression in buccal mucosa was determined with quantitative RT-PCR for the following genes: CCL2, EDN1, FKBP5, IL8, IFNAR2, NFKB1, RELA, SERPINB2, DENND1B, HRH1, ICAM1, ORMDL3, NR3C1, CLCA1, CRHR1, MUC5B, FCER2, POSTN, GAPDH, PPIA. Results mRNA Expression of the following genes was detected in buccal mucosa: CCL2, EDN1, FKBP5, IL8, IFNAR2, NFKB1, RELA, SERPINB2, DENND1B, HRH1, ICAM1, ORMDL3, NR3C1, GAPDH, PPIA. HRH1 was differentially expressed in adults with asthma vs. controls (p=0.04), and EDN1 was differentially expressed in children with asthma vs. controls 1218years old (p=0.03). A similar trend for HRH1 was observed in children 1218years old. Conclusions Buccal mucosa sampling is a reliable method for detecting changes in gene expression in patients with asthma. This non-invasive technique may serve as a valuable tool for diagnosing asthma and evaluating therapeutic response.