Glucocorticoid receptor subunit expression in adenotonsillar tissue of children with obstructive sleep apnea

Tonsillectomy and adenoidectomy (T&A) is a frequent surgical procedure in children with obstructive sleep apnea (OSA). Many symptomatic children who do not fulfill the currently recommended criteria for T&A may benefit from topical intranasal steroid therapy. However, the expression of glucocorticoid receptor (GCR) expression in adenoid and tonsillar tissue is currently unknown. The objective of this study was to assess and compare expression patterns of the human GCR in children who undergo T&A for either recurrent throat infections (RI) or OSA. Adenotonsillar tissues from 36 children with OSA or RI were subjected to quantitative PCR using specific primers for GCR-alpha and GCR-beta and to immunohistochemistry and Western blotting for protein expression of GCR isoforms. mRNA encoding for expression of both GCR-alpha and GCR-beta was detected in the tonsils and adenoids of all children, with markedly higher relative abundance of the GCR-alpha. Furthermore, GCR-alpha mRNA expression was increased in OSA-derived adenoid and tonsil tissues compared with RI, whereas no differences emerged for GCR-beta. Immunoblots confirmed these findings for the protein transcripts of these genes, and immunohistochemistry showed a specific topographic pattern of distribution for both receptors in tonsillar tissue. GCR-alpha and GCR-beta are expressed in pediatric adenotonsillar tissue, are more abundant in OSA patients, and demonstrate a specific topographic pattern of expression. These findings along with the high GCR-alpha:GCR-beta ratio suggest a favorable profile for topical steroid therapy in snoring children with adenotonsillar hypertrophy.