Background: Nasal polyposis has different etiologies in Western and Eastern countries. Furthermore, its pathogenesis is still poorly understood.

Objective: To determine the T-cell phenotypes involved in nasal polyposis in Chinese patients.

Methods: Twenty-four Chinese patients with nasal polyps were studied. CD4, CD8, Foxp3, and interleukin (IL) 17 were analyzed by immunohistochemical staining. Expression of T-bet, GATA-3, Foxp3, and RORγt mRNA was detected by real-time polymerase chain reaction. The levels of T-cell cytokines (IL-4, IL-5, interferon [IFN] γ, IL-10, IL-17, and transforming growth factor [TGF] ß) were determined using
enzyme-linked immunosorbent assay, and serum immunoglobulin (Ig) E levels were measured using the UNICAP system.

Results: Increased expression of CD4+ and CD8+ and decreased expression of Foxp3 and IL-17 were detected in nasal polyps compared with control tissue. Furthermore, expression of T-bet and GATA-3 mRNA was upregulated, whereas Foxp3 mRNA expression was markedly downregulated. Furthermore, increased levels of IFN-γ, IL-4 and IL-5 and decreased levels of IL-10 and TGF-ß were found in nasal polyps. There
was no association between Staphylococcus aureus exotoxin (SAE)-specifi c IgE and T regulatory cell (Treg) insufficiency in nasal polyps.

Conclusions: Our findings demonstrate that excessive infiltration of CD4+ and CD8+ T cells in nasal polyps may be associated with expression of Foxp3+ by Tregs but not with SAEs in Chinese patients.

Key words: Chronic rhinosinusitis. Nasal polyps. T regulatory cells. Transcription factor. Cytokine.