The role of superantigens in chronic rhinosinusitis with nasal polyps

Recent reports suggest that staphylococcal exotoxins, acting as superantigens, activate T cells with subsequent massive proliferation, thereby contributing to the etiology of chronic rhinosinusitis with nasal polyps (CRSwNP). The objectives of this study are (1) to demonstrate directly the presence of staphylococcal exotoxins in nasal mucosa and sinonasal polyp tissue, and (2) provide indirect evidence of the effect of superantigens on the T cells expressing the target of superantigen, i.e., the beta variable chain receptor (TCRBV) in polyp tissue and peripheral blood of patients with CRSwNP. Sinonasal polyp tissue and peripheral blood specimens were obtained from 37 patients with chronic rhinosinusitis (22 patients with bilateral nasal polyps, 15 without nasal polyps) and 12 normal subjects for comparative negative controls. Tissue specimens were assayed by enzyme-linked immunosorbent assay (ELISA) for the most common staphylococcal exotoxins (A-D) and toxic shock syndrome toxin type 1. Fresh tissue and blood samples were analyzed by flow cytometry to determine the expression of TCRBV. In the CRSwNP subjects 12 of 22 samples (54.54%) demonstrated reactivity for at least 1 staphylococcal exotoxin, while 2 of the 12 were positive for 2 toxins. There were no positive results in the CRS without nasal polyps or control groups. There was a clear trend of increased TCRBV expression in the ELISA-positive group both for tissue and blood specimens. Staphylococcal superantigens were present in the nasal cavity of patients with CRSwNP with a high percentage of TCRBV, which suggests the possibility of superantigens as etiological agents of CRSwNP.