Increased IgE Deposition in Appendicular Tissue Specimens Is Compatible with a Type I Hypersensitivity Reaction in Acute Appendicitis

Abstract

Background. IgE mediates type I hypersensitivity reaction and can be found in the mucosa of organs affected by allergy. Acute appendicitis (AA) is a common disease, but its etiology remains poorly understood. Here, we investigated IgE deposition in histological sections of AA samples to test the hypothesis that an allergic reaction may substantially contribute to the pathophysiology of AA. Materials and Methods. In a retrospective study, we assessed the presence of IgE in appendicular specimens of histologically confirmed appendicitis and in the control group, comprised of negative appendicitis and incidental appendectomies, using a monoclonal antibody against human IgE. Samples from 134 appendectomies were included: 38 phlegmonous and 27 gangrenous appendicitis from the study group and 52 incidental appendectomies and 17 negative appendicitis from the control group. The slides were visualized by light microscopy, and a standard procedure was used to manually count the positive IgE staining cells. Results. IgE staining was present in the cells of all but 5 appendicular specimens. We found a significantly increased number of IgE-positive cells in phlegmonous AA ( median = 28 ) when compared to incidental appendectomy ( median = 17 ) ( p = 0.005 ; p < 0.0001 when adjusted for age and gender). No difference was found for gangrenous appendicitis. Discussion. The presence of IgE supports the contribution of an allergic reaction for the pathophysiology of phlegmonous appendicitis. The reduced number of IgE staining cells in gangrenous appendicitis can be due to tissue destruction, or, as been claimed by others, gangrenous appendicitis is a distinct entity, with different etiology. Conclusion. In this study, phlegmonous appendicitis had the highest number of IgE-positive appendicular cells. These findings suggest that an allergic reaction can contribute to the pathophysiology of AA, opening a novel possibility for preventive measures in a disease that typically requires surgery.

IL-5 Serum and Appendicular Lavage Fluid Concentrations Correlate with Eosinophilic Infiltration in the Appendicular Wall Supporting a Role for a Hypersensitivity Type I Reaction in Acute Appendicitis

“…The lower number of eosinophils was detected in AGA. When we analysed the presence of IgE in the walls of AA specimens, a similar distribution of intensity was reported [ 6 ].…”

“…Some contemporary insights suggest that allergy may be an important player in AA [ 3 , 4 ]. Recent and ongoing results of our group corroborate this line of research [ 5 , 6 ] and allergy was searched for as the “missing link” in the aetiology of AA [ 7 ]. If, in this narrative revision [ 7 ], a definitive causal relation between allergy and acute AA could not be established, it was well stated that allergic features are undoubtedly present in AA [ 5 , 6 , 7 , 8 , 9 ].…”

“…Recent and ongoing results of our group corroborate this line of research [ 5 , 6 ] and allergy was searched for as the “missing link” in the aetiology of AA [ 7 ]. If, in this narrative revision [ 7 ], a definitive causal relation between allergy and acute AA could not be established, it was well stated that allergic features are undoubtedly present in AA [ 5 , 6 , 7 , 8 , 9 ]. Addressing the allergic component of AA is a field of interest for future research that may sustain recent changes in clinical decision-making [ 5 , 10 , 11 ].…”

“…An elevation of Th2 cytokine profile (IL-4, IL-5, and IL-9) was documented in the ALF of phlegmonous appendicitis [ 5 ]. Furthermore, using a monoclonal antibody anti-IgE, we found high levels of IgE fixation in appendicular specimens of phlegmonous appendicitis [ 6 ]. These data corroborate the interest for exploring the allergic component in phlegmonous appendicitis, foreseeing a possible incorporation of the incoming results in the clinical reasoning.…”

An Evaluation of Serum IgE and Th2-Associated Interleukins in Children With Uncomplicated and Complicated Appendicitis

“…Based on this hypothesis, we conducted our previous studies on the association between (the Th2 associated) IgE-mediated allergy and a lower risk of complicated appendicitis ( 15 , 16 ), which have now been continued in the present study through measurement of the IgE-levels. Previous studies from other authors have found a significant increase in IgE deposits in phlegmonous appendices compared to incidentally removed appendices, but not compared to gangrenous appendicitis and negative appendectomies ( 17 ). Furthermore, two studies have reported significant associations of eosinophilia and uncomplicated appendicitis in children ( 18 , 19 ).…”