Increased thrombin activatable fibrinolysis inhibitor (TAFI) in chronic rhinosinusitis with nasal polyps

Abstract Background Chronic rhinosinusitis (CRS) is a heterogeneous chronic inflammatory disease subdivided based on presence or absence of nasal polyps (NPs). Histological features of CRS with NPs (CRSwNP) include inflammatory cell infiltration and excessive fibrin deposition in nasal polyps. Thrombin activatable fibrinolysis inhibitor (TAFI) is an enzyme that plays an anti-fibrinolytic role in the body. The significance of TAFI has been documented in chronic inflammatory diseases including chronic lung disease; however, it has not been evaluated in the pathogenesis of NPs. Objective The objective of this study was to evaluate the potential role of TAFI in the pathogenesis of NPs. Methods Nasal lavage fluids were collected from control subjects and patients with CRS. We measured levels of thrombin/anti-thrombin complex (TATc) and TAFI protein by ELISA. Results TATc levels in nasal lavage fluids were significantly increased in patients with CRSwNP and CRS without NPs (CRSsNP) compared with control subjects, and levels of TAFI in nasal lavage fluids were also significantly elevated in CRSwNP subjects compared with control subjects and CRSsNP subjects. There was a significant correlation between levels of TATc and TAFI in nasal lavage fluids. Interestingly, patients with CRS and asthma showed increased TATc and TAFI in nasal lavage fluids compared to CRS without asthma, especially in patients with CRSwNP. Conclusions Elevated TATc and TAFI in nasal passages of patients with CRSwNP might participate in fibrin deposition in NPs and may play a role in the pathogenesis of CRSwNP and asthma.