TIM-3-driven macrophage polarisation is associated to recalcitrant chronic rhinosinusitis with nasal polyps.

OBJECTIVE

This study evaluated the expression of TIM-3 and its influence on macrophage polarisation in recalcitrant chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

We detected TIM-3 expression in serum and tissue samples of healthy controls (HC), primary CRSwNP, and patients with recurrent CRSwNP. Macrophage markers were detected among three groups, and their correlations with TIM-3 levels were examined. Macrophages from circulating blood were collected and used to examine the impact of TIM-3 on polarisation in vitro.

RESULTS

TIM-3 levels were enhanced in the CRSwNP group compared to the HC group. Tissue immunofluorescence revealed elevated TIM-3 expression in patients with CRSwNP, and patients with multiple recurrences exhibited higher TIM-3 levels compared to their first recurrence and baseline levels. Tissue CD163 and CD206 levels were higher in recurrent CRSwNP in comparison with primary cases and HCs, and had a positive correlation with TIM-3 levels. TIM-3 overexpression promoted M2 polarisation and enhanced TGF-β1 and IL-10 secretion.

CONCLUSIONS

TIM-3 expression was enhanced in patients with CRSwNP, especially in those undergoing revision surgeries. TIM-3 may be a novel biomarker for recalcitrant CRSwNP. TIM-3-driven M2 polarisation might be involved in the mechanisms of recurrent CRSwNP.