Inflammatory mediators in Nasal polyposis
Inflammatory mediators identified in nasal polyposis: Many chemical mediators with different inflammatory activities have been described in patients with nasal polyposis. These mediators have been classifed into four groups by Hoffmann and Wassermann.
1. Substances with vasoactive function: These substances have their effect on blood vessels causing vasodilatation, neovascularization etc. Examples of these mediators include: Platelet activating factor (PAF), prostaglandins,leukotrienes, norepinephrine, neuropeptid, vasoactive intestinal peptide (VIP).
2. Substances influencing cell migration: High molecular weight neutrophil chemotactic factor (HMW-NCF), eicosanoidswhich include prostaglandins and leucotrienes, interleukins, chemokines, and adhesion molecules (selectins, integrins, cadherins, mucins and immunoglonulins).
3. Substances acting on extracellular matrix: These include transforming growth factor (TGF), tumor necrosis factor (TNF), and vasoactive intestinal polypeptide (VIP).
4. Mediators that affect cell growth, differentiation and proliferation: These include transforming growth factor (TGF), colony stimulating factor (CSF), insulin like growth factor (IGF), tumor necrosis factor (TNF), and interleukins (IL).