Gene Expression of MMP‐1, MMP‐2, MMP‐9, and TIMP‐1 in Nasal Polyps

Objective Edema in nasal polyps (NP) is related to extracellular matrix degeneration, which is regulated by MMPs (matrix metalloproteinases) and their inhibitor, TIMP. Several studies relate MMP and TIMP expression to airway inflammatory diseases. The purpose of this study was to evaluate which is MMP and TIMP expression in Brazilian NP. Method Thirty NPs were compared with 19 controls. MMP1, MMP2, MMP9, and TIMP1 mRNAs expression was evaluated by RQTPCR. Also, PCR results were correlated to extensiveness of disease. PCR data were analyzed through Student t test, and the correlation between PCR and clinical results was performed by Spearman test. Results NPs presented significantly higher expression of MMP‐1 (9.79 ± 12.62 for NP vs 1.38 ± 1.21 for middle turbinates, P vs 0.83 ± 0.61 for middle turbinates, P vs 90 ± 0.56 for middle turbinates, P <. 05). TIMP‐1 expression was detected neither in NP nor in middle turbinates. There was no correlation between clinical findings and gene expression. Conclusion Brazilian NP presented higher expression of all the 3 studied MMPs (MMP1, MMP2, and MMP9), but not of TIMP1. This pattern is very similar to that observed for NP in the literature. There is no correlation between gene expression and extensiveness of the disease.