Investigation on the expression of microvessel pericyte coverage index and lymph vessel density in nasal polyps

Objective To investigate the role of lymph vessel density (LVD) and microvessel pericyte coverage index (MPI) in the pathogenesis of nasal polyps. Methods Using immunohistochemistry and immunofluorescence double staining method, the expressions of albumin, D2-40 and CD34-α-SMA in 11 specimens of normal nasal mucosa, 26 specimens of nasal polyp and 26 specimens of inferior turbinate tissue from patients with nasal polyps were investigated. The counts of microvessel density (MVD), lymph vessel density (LVD) and microvessel pericyte coverage index (MPI) were compared. SPSS 17.0 software was used to analyze the data. Results The nasal polyp group(0.269±0.096) had more albumin than inferior turbinate tissue group(0.159±0.078) and normal nasal mucosa group(0.138±0.045), the differences were significant (q value was 4.873, 4.446, both P 0.05). The MPI in nasal polyp group (0.291±0.096) was significantly lower than those in inferior turbinate tissue group(0.432±0.101) and normal nasal mucosa group(0.416±0.071), the difference was significant (q value was 5.399, 3.680, both P<0.05). The counts of LVD in the nasal polyp group(0.245±0.073) were significantly lower than those in inferior turbinate tissue group (0.431±0.054) and normal nasal mucosa group(0.470±0.078), the difference was significant (q value was 10.004, 9.328, both P<0.05). MPI expression in the nasal polyp group was negetively correlated to albumin expression(r=-0.889, P<0.05). The LVD expression in the nasal polyp group was negetively correlated to albumin expression(r=-0.901, P<0.05). Conclusion Different LVD and MIP in nasal polyp tissues and normal nasal mucosa tissues imply that microcirculatory dysfunction plays a crucial role in the pathogenesis of nasal polyps. Key words: Nasal polyps; Microcirculation; Capillaries; Lymphatic vessels; Pericytes microvessel