I. Preface
(A) Nasal mucosal tissue is the same as all multicellular organisms
There is a dynamic balance between cell proliferation and apoptosis. Thus enough into can control the size of the cell population and maintain the stability of the multicellular organism, as well as can maintain the physiological function of the organism. This is important for the control and regression of diseases. If the cell proliferation is excessive or apoptosis is reduced, it can lead to the occurrence and development of some diseases, for example, multiple nasal polyps is one of the diseases of excessive proliferation. Repeated episodes of multiple nasal polyps are characterized by the active proliferation and weakened apoptotic activity of the epithelial cells of nasal polyps, so clinically multiple nasal polyps are a treatable but incurable disease.
(B) Correlation between pathological features of allergic rhinitis and multiple nasal polyps.
Pathological features of allergic rhinitis: interstitial edema of the nasal mucosa, tissue gland formation and inflammatory cell infiltration (neutrophils and eosinophils). Clinically, pale edema of the nasal mucosa is seen. Under long-term inflammatory stimulation of the nasal mucosa, the epithelial cells of the nasal mucosa as well as the sinus mucosa proliferate excessively and differentiate abnormally, forming the initial form of multiple nasal polyps. The clinical manifestation is widespread pale edema of the nasal mucosa, which further increases in size and the formation of new glands, eventually forming multiple nasal polyps.
Due to the correlation between allergic rhinitis and multiple nasal polyps, it can be considered that the development trend of allergic rhinitis is multiple nasal polyps, multiple nasal polyps is the development and evolution of allergic rhinitis and the formation of.
Second, the pathological and histological characteristics of multiple nasal polyps
Interstitial edema, inflammatory cell infiltration (neutrophils and eosinophils), interstitial gland formation and vascular hyperplasia, excessive proliferation of interstitial epithelial cells.
C. Categories of multiple nasal polyps
(a) Multiple nasal polyps with tips: This type is composed of multiple polyps with tips, and each individual nasal polyp with tips is seen during surgery, mostly present in the middle nasal tract or the top of the nose.
(b) Extensive edematous polyps of the mucosa of the nasal cavity and sinuses: this type shows extensive edema of the mucosa of the nasal cavity and sinuses, polypoid changes of the mucosa of the middle turbinate and polypoid changes of the mucosa of the high end of the nasal septum. This type of multiple nasal polyps is exactly one of the clinically treatable, but difficult to cure categories. Because its development is associated with a variety of cytokines.
IV. Problems associated with excessive proliferation of nasal polyps
Infection and metaplasia are among the most important factors
(a) Inflammatory cell infiltration, whether in the nasal mucosa of patients with allergic rhinitis or in the stroma of polyps of patients with multiple nasal polyps or in the proliferating vessels of the stroma there are a large number of inflammatory cells, inflammatory cells are mainly neutrophils and eosinophils, and eosinophils account for 20% of inflammatory cells, and are activated eosinophils, it is these eosinophils are the cause of nasal polyps The key to the occurrence, development and enlargement of nasal polyps, and is also the key to cause easy recurrence after surgery.
(B) allergic reactions, the capillaries and small blood vessels in the nasal mucosa of patients with allergic rhinitis have high permeability, which leads to the formation of nasal mucosa edema. In the edematous mucosal stroma, there is also a large number of inflammatory cell infiltrates, which are also dominated by eosinophils.
V. Factors dominating the occurrence and development of nasal polyps
The increase of eosinophils and the activation of eosinophils are the key to the formation, occurrence and development of multiple nasal polyps. The involvement of various cytokines and the rise in expression of eosinophils promote the increase in the amount of eosinophils and the enlargement and development of multiple nasal polyps. Certainly eosinophils are an important link in the development of
(A) Vascular endothelial growth factor, and its receptor-1 and receptor-2 expression increase, in addition to causing severe edema in the nasal mucosa and nasal polyp stroma, the proliferation and expansion of microvessels in the stroma, leading to inflammatory cell infiltration, again with eosinophils as the main component.
In normal nasal mucosa vascular endothelial growth factor expression is low in magnitude and appears very strongly when inflammatory infiltration or metaplasia occurs. Moreover, the density of microangiogenesis in the stroma of nasal polyps is consistent with an increase in the degree of edema.
The increased expression of VEGF not only proliferates epithelial cells of nasal polyps, but also inhibits the apoptosis of epithelial cells of nasal polyps, which contributes to the recurrence of nasal polyps after surgery. Therefore, blocking the expression of VEGF can prevent the recurrence of nasal polyps after surgery.
VEGF and its receptor-1 and receptor-2 are present in the cytoplasm, and the number of eosinophil infiltrates in the stroma of multiple nasal polyps is significantly higher than that of eosinophil expression in the stroma of allergic rhinitis and single nasal polyps.
(B) Interleukins are involved in the development and progression of allergic diseases. The onset of allergic rhinitis and nasal polyps, and their development are associated with many cytokines. Significantly elevated serum levels of IgE, interleukin-5, and interleukin-4 are among their characteristics. When allergic rhinitis strikes, the occurrence of cytokines and the involvement of inflammatory mediators are associated with abnormal immune regulation of the organism. The synthesis and secretion of IgE is promoted by the release of cytokines and the infiltration and activation of inflammatory cells is increased, the most important of which is the activation of eosinophils. Serum levels of interleukins in patients with allergic rhinitis are 3-4 percentage points higher than in normal subjects.