The Significance of Mast Cells and Eosinophils Counts in Surgically Resected Appendix

Abstract

Objectives: The mast cell remains an enigmatic cell, found resident in tissues throughout the body particularly in association with structures such as blood vessels and nerves. Various inflammatory disorders of the intestines, joints and lungs appear to be associated with an increase in mast cell numbers. The study was conducted on vermiform appendix. The present study was undertaken (1) to compare the mast cell and eosinophil counts in various layers of the appendix in various histopathological groups, and (2) to establish the relationship between the numbers of eosinophils and mast cells in the inflamed appendix. Materials and Methods: The material for study consisted of appendix specimens received for histopathological examination in the Department of pathology. A 5 year study was conducted, 3 years retrospective and 2 years prospective. Results: Out of 777 cases studied the incidence of appendicitis is high, in the first and second decades of life and slightly higher in females. Recurrent appendicitis was more common when compared to other inflamed appendices. Conclusions: Eosinophil counts in all the layers were very high in acute eosinophilic appendicitis compared to normal appendices. A higher mast cell count was seen in acute eosinophilic appendicitis and recurrent appendicitis. No correlation was found between mast cell and eosinophilic density. Our observations support the allergic theory of appendicitis rather than the obstructive theory.

Study of mast cell and eosinophil count in surgically resected appendix

“…In the present study the mean mast cell count was found to be highest in mucosa followed by submucosa and then muscularis propria, but study by Verma A et al [13] found that mast cells were more easily identified in submucosa. In comparison of the findings in the present study and study by Kolur A et al [7], mean mast cell count was highest in chronic appendicitis, followed next in frequency by acute appendicitis and acute suppurative appendicitis compared to normal / unremarkable appendix and the mean mast cell count in chronic appendicitis and acute appendicitis was highest in the mucosa, followed by submucosa and muscularis propria in Kolur A et al [7] study, these results were in concordance with the present study. [7] showed few contrary results with the present study, where they found the mean mast cell count in acute suppurative to be highest in muscularis propria followed by mucosa then submucosa, however in the present study the mean mast cell count was found to be highest in the mucosa, followed by submucosa then muscularis propria.…”

“…In comparison of the findings in the present study and study by Kolur A et al [7], mean mast cell count was highest in chronic appendicitis, followed next in frequency by acute appendicitis and acute suppurative appendicitis compared to normal / unremarkable appendix and the mean mast cell count in chronic appendicitis and acute appendicitis was highest in the mucosa, followed by submucosa and muscularis propria in Kolur A et al [7] study, these results were in concordance with the present study. [7] showed few contrary results with the present study, where they found the mean mast cell count in acute suppurative to be highest in muscularis propria followed by mucosa then submucosa, however in the present study the mean mast cell count was found to be highest in the mucosa, followed by submucosa then muscularis propria. Increase in mast cells in acute appendicitis together with the broad spectrum of activities of mast cell derived mediators was seen in studies done by Sonti S [8], Sharma J et al [14], Kumaran C et al [15] and Bhramarambha K et al [11].…”

“…Type I hypersensitivity reaction causes degranulation of mast cells, release of mediators by mast cells might be another triggering factor for the sequence of events leading to appendicitis [12]. Correlation between mast cell density, neural ganglia hypertrophy and fibrosis in cases of chronic appendicitis as seen in the present study was in concordance with studies conducted by Nagaraj G et al [4], Kolur A et al [7], Sonti S et al [8], Sharma J et al [14], Kumaran C et al [15] and Naik R et al [16], mast cells have been implicated in the pathogenesis of fibrosis and neuronal hypertrophy in chronic appendicitis due to release of growth factors leading to fibroblastic and neuronal proliferation, this was in agreement with the findings in the other studies [4,7,8,14,15,16]. In the present study highest mean eosinophil count was seen in the mucosa of acute suppurative appendicitis and lowest eosinophil count was seen in the muscularis propria of chronic appendicitis.…”

“…Eosinophilic infiltration of muscularis propria has been seen in acute appendicitis and it is postulated that acute appendicitis is triggered by Type I hypersensitivity [6]. Hence mast cells and eosinophils have important role to play in the pathogenesis of appendicitis as concluded by many studies [4,5,6,7,8,9,10,11,12].…”

Th2 cytokine profile in appendicular lavage fluid is compatible with allergy as an etiology for acute appendicitis

“…Appendicular sections were sampled from the tip, base and intermediate length for fixation and paraffin processing. Two sections of 5-micron thickness were cut from each paraffin block and stained by hematoxylin & eosin (8). The criteria for AA was polymorphous nuclear neutrophils infiltration at the muscularis propria (9).…”