Characterization of the T-cell subpopulations in the granulation tissues of chronic suppurative otitis media.

The present study aimed to investigate the potential involvement of specific T-cell subpopulations in granulation tissue formation in chronic suppurative otitis media (CSOM). Fifteen patients with CSOM were enrolled in this study. Granulation tissues were obtained from the middle ear cavity. Hematoxylin and eosin staining was performed for histopathological observation, and different T-cell subpopulations were characterized by immunohistochemistry. No evident association was identified between granulation tissue formation and disease course. The number of cluster of differentiation 8+ (CD8+ ) T cells, forkhead box P3+ (FOXP3+ ) regulatory T (Treg) cells and OX40+ T cells were significantly higher in granulation tissues from patients with ear discharge within the last 6 months compared to those without (P<0.05). Fresh granulation tissues had more CD8+ T cells and FOXP3+ Treg cells compared to the mature granulation tissues (P<0.05). There was a differential abundance of specific T-cell subpopulations in the granulation tissues in CSOM with different disease courses or with ear discharge, suggesting that T cell-mediated cellular immunity is involved in lesion formation of CSOM.