Immune cell profile in invasive cholesteatomas: Preliminary findings

The Science of Cholesteatoma

Cholesteatoma is a potential end-stage outcome of chronic ear infections that can result in the destruction of temporal bone structures with potential resultant hearing loss, vertigo, and intracranial infectious complications. There is currently no treatment apart from surgery for this condition, and despite years of study, the histopathogenesis of this disease remains poorly understood. This review is intended to summarize our accumulated knowledge of the mechanisms of cholesteatoma development and the underlying molecular biology. Attention will be directed particularly to recent developments, covering many potential pharmacologic targets that could be used to treat this disease in the future.

Biology of recurrent cholesteatoma in a Romanian young patient - a case report

Cholesteatoma is an otologic pathology that can occur at any age and can lead to a variety of complications including facial palsy, intracranial abscess, hearing loss, venous thrombosis. Cholesteatoma, even if considered a benign condition, associates high risks of recurrency due to its invasiveness. We describe a case of recurrent cholesteatoma in a young boy who presented chronic ear discharge and hearing loss for which had undergone three surgical interventions between the ages of 16 and 19 years old, from 2019 to 2022. Pediatric cholesteatoma is more prone to recurrency. Considering surgical excision as the only treatment at the current moment, it is highly important to understand the biology of cholesteatoma lesional extension for further treatment management improvement. Good research of angiogenesis, chronic inflammation and immune infiltration correlated with surgical approach may be the future for preventing cholesteatoma recurrency.

Morphopathogenesis of Adult Acquired Cholesteatoma

Background and Objectives. The aim of this study was to compare the distribution of proliferation markers (Ki-67, NF-κβ), tissue-remodeling factors (MMP-2, MMP-9, TIMP-2, TIMP-4), vascular endothelial growth factor (VEGF), interleukins (IL-1 and IL-10), human beta defensins (HβD-2 and HβD-4) and Sonic hedgehog gene protein in cholesteatoma and control skin. Methods. Nineteen patient cholesteatoma tissues and seven control skin materials from cadavers were included in the study and stained immunohistochemically. Results. Statistically discernible differences were found between the following: the Ki-67 in the matrix and the Ki-67 in the skin epithelium (p = 0.000); the Ki-67 in the perimatrix and the Ki-67 in the connective tissue (p = 0.010); the NF-κβ in the cholesteatoma matrix and the NF-κβ in the epithelium (p = 0.001); the MMP-9 in the matrix and the MMP-9 in the epithelium (p = 0.008); the HβD-2 in the perimatrix and the HβD-2 in the connective tissue (p = 0.004); and the Shh in the cholesteatoma's perimatrix and the Shh in the skin's connective tissue (p = 0.000). Conclusion. The elevation of Ki-67 and NF-κβ suggests the induction of cellular proliferation in the cholesteatoma. Intercorrelations between VEGF, NF-κβ and TIMP-2 induce neo-angiogenesis in adult cholesteatoma. The similarity in the expression of IL-1 and IL-10 suggests the dysregulation of the local immune status in cholesteatoma. The overexpression of the Sonic hedgehog gene protein in the cholesteatoma proves the selective local stimulation of perimatrix development.

A Role for Mast Cell-Mediated Antibodies in the Formation of Cholesteatoma and Cholesteatoma-Induced Bone Erosion

The study aimed to evaluate the effects and relationships between mast cells in the matrix, mast cell enzymes tryptase and chymase, epithelial proliferation, microvascular density, and bone destruction in cholesteatoma. Thirty-five biopsies diagnosed with cholesteatoma and seven healthy skin tissues taken from the retro-auricular region for control were evaluated. Immunohistochemical studies were performed with CD117, CD34, Ki-67, chymase, and tryptase antibodies, in a single session for all cases and the control group. The relationship between erosion size and antibody load was determined. The mean cholesteatoma epithelium Ki-67 was higher than the control group (p < 0.001). CD117-positive mast cells, chymase-positive mast cells, tryptase-positive mast cells, and microvessel density were significantly higher in the cholesteatoma matrix compared to the control group (p < 0.002, p < 0.001, p < 0.005). In the group with bone erosion scores of two and above, immunohistochemical markers tended to be higher. A positive correlation was found between CD117 and chymase, tryptase, and microvessel density; between tryptase, chymase, and microvessel density; and between chymase and microvessel density. CD117-positive mast cells and chymase-positive mast cells stimulate angiogenesis, increase the epithelium's proliferative capacity in the cholesteatoma matrix, and form cholesteatoma. The increased proliferation of cholesteatoma epithelium and increased vascular density in the matrix exacerbate bone erosion.

Review of potential medical treatments for middle ear cholesteatoma

Middle ear cholesteatoma (MEC), is a destructive, and locally invasive lesion in the middle ear driven by inflammation with an annual incidence of 10 per 100,000. Surgical extraction/excision remains the only treatment strategy available and recurrence is high (up to 40%), therefore developing the first pharmaceutical treatments for MEC is desperately required. This review was targeted at connecting the dysregulated inflammatory network of MEC to pathogenesis and identification of pharmaceutical targets. We summarized the numerous basic research endeavors undertaken over the last 30+ years to identify the key targets in the dysregulated inflammatory pathways and judged the level of evidence for a given target if it was generated by in vitro, in vivo or clinical experiments. MEC pathogenesis was found to be connected to cytokines characteristic for Th1, Th17 and M1 cells. In addition, we found that the inflammation created damage associated molecular patterns (DAMPs), which further promoted inflammation. Similar positive feedback loops have already been described for other Th1/Th17 driven inflammatory diseases (arthritis, Crohn’s disease or multiple sclerosis). A wide-ranging search for molecular targeted therapies (MTT) led to the discovery of over a hundred clinically approved drugs already applied in precision medicine. Based on exclusion criteria designed to enable fast translation as well as efficacy, we condensed the numerous MTTs down to 13 top drugs. The review should serve as groundwork for the primary goal, which is to provide potential pharmaceutical therapies to MEC patients for the first time in history.

The Relationship between the M1/M2 Macrophage Polarization and the Degree of Ossicular Erosion in Human Acquired Cholesteatoma: An Immunohistochemical Study

The differential involvement of the macrophage activation phenotypes (M1 vs. M2) has been linked to disease severity in various chronic inflammatory disorders. Pharmacologic manipulation of the M1/M2 macrophage polarization has shown therapeutic potential. Cholesteatoma is a destructive chronic middle ear disease with potentially life-threatening complications. The distribution of macrophage polarization phenotypes in middle ear cholesteatoma has not been described. In the present study, human cholesteatoma specimens acquired during tympanomastoidectomy were retrospectively retrieved and immunohistochemically characterized using a combination of antibodies labeling M1 macrophages (CD80), M2 macrophages (CD163), and total macrophages (CD68). The correlations between the immunohistochemical findings and clinical presentation were assessed. The findings revealed that cholesteatomas with more extensive ossicular erosion demonstrated a significantly higher number of M1 (CD80+) cells and a higher M1/M2 ratio than less invasive cholesteatomas (Wilcoxon test, p < 0.05). The extent of ossicular erosion correlated significantly with the M1/M2 ratio (Spearman correlation coefficient ρ = 0.4, p < 0.05). Thus, the degree of ossicular erosion in human acquired cholesteatoma appears to be related to the M1/M2 macrophage polarization. The investigation of macrophage polarization and functions in various clinical presentations of middle ear cholesteatoma is of great interest since it may contribute to the development of pharmaceutical treatment approaches.

Immunohistochemical analysis of S100-positive epidermal Langerhans cells in dermatofibroma

Dermatofibroma is a dermal fibrohistiocytic neoplasm. The Langerhans cells are the immunocompetent cells of the epidermis, and they represent the first defense barrier of the immune system towards the environment. The objective was to immunohistologically compare the densities of S100-positive Langerhans cells in the healthy peritumoral epidermis against those in the epidermis overlying dermatofibroma (20 cases), using antibodies against the S100 molecule (the immunophenotypic hallmark of Langerhans cells). The control group (normal, healthy skin) included ten healthy age and sex-matched individuals who underwent skin biopsies for benign skin lesions. A significantly high density of Langerhans cells was observed both in the epidermis of the healthy skin (6.00 ± 0.29) and the peritumoral epidermis (6.44 ± 0.41) vs. those in the epidermis overlying the tumor (1.44 ± 0.33, p < 0.05). The quantitative deficit of Langerhans cells in the epidermis overlying dermatofibroma may be a possible factor in its development.

Pathogenesis and Bone Resorption in Acquired Cholesteatoma: Current Knowledge and Future Prospectives

Cholesteatoma is a cystic non tumorous lesion of the temporal bone that has the ability to destroy nearby structures by its power to cause bone resorption and as a result, fatal complications prevail. We aimed to conduct a comprehensive review for pathogenesis of acquired cholesteatoma, bone resorption mechanisms, and offer a future vision of this serious disease. We have reviewed different theories for pathogenesis of acquired cholesteatoma including the most relevant and updated ones with special emphasis on the mechanisms of bone resorption through Medline/PubMed research using the keywords 'aetiopathogenesis, bone resorption, acquired cholesteatoma, temporal bone, and cytokines.' In order to strengthen our study, we searched the reference lists of identified reviews. Cholesteatoma is a subject of debate among otolaryngologists since it was prescribed firstly. Over many decades, several theories were postulated for aetiopathogenesis of cholesteatoma with a tendency to follow more than one theory to explain the proper nature of that disease. Until now, the mechanism of bone resorption has yet to be more clarified. In the last century, a leap has occurred in the field of biomolecular cholesteatoma research which improved our knowledge about its pathophysiology and bone destructive mechanism. However, surgery is still the only available treatment. We conclude that discovery of new therapeutic choices for cholesteatoma other than surgery by the use of anti-growth, anti-proliferative, apoptotic agents as well as medications that antagonize osteoclastogenesis should be the main concern in the future clinical and experimental research work. Also, searching for predictors of the aggressiveness of cholesteatoma can affect the timing of intervention and prevent occurrence of complications.

Large-scale proteomics differentiates cholesteatoma from surrounding tissues and identifies novel proteins related to the pathogenesis

Cholesteatoma is the growth of keratinizing squamous epithelium in the middle ear. It is associated with severe complications and has a poorly understood etiopathogenesis. Here, we present the results from extensive bioinformatics analyses of the first large-scale proteomic investigation of cholesteatoma. The purpose of this study was to take an unbiased approach to identifying alterations in protein expression and in biological processes, in order to explain the characteristic phenotype of this skin-derived tumor. Five different human tissue types (cholesteatoma, neck of cholesteatoma, tympanic membrane, external auditory canal skin, and middle ear mucosa) were analyzed. More than 2,400 unique proteins were identified using nanoLC-MS/MS based proteomics (data deposited to the ProteomeXchange), and 295 proteins were found to be differentially regulated in cholesteatoma. Validation analyses were performed by SRM mass spectrometry. Proteins found to be up- or down-regulated in cholesteatoma were analyzed using Ingenuity Pathway Analysis and clustered into functional groups, for which activation state and associations to disease processes were predicted. Cholesteatoma contained high levels of pro-inflammatory S100 proteins, such as S100A7A and S100A7. Several proteases, such as ELANE, were up-regulated, whereas extracellular matrix proteins, such as COL18A1 and NID2, were under-represented. This may lead to alterations in integrity and differentiation of the tissue (as suggested by the up-regulation of KRT4 in the cholesteatoma). The presented data on the differential protein composition in cholesteatoma corroborate previous studies, highlight novel protein functionalities involved in the pathogenesis, and identify new areas for targeted research that hold therapeutic potential for the disease.

44-plex cytokine profile of cholesteatoma

CONCLUSION

A nuanced profiling was achieved by the simultaneous analysis of 44 cytokines in cholesteatoma. The novel discovery of high levels of interleukin 21 (IL21) in cholesteatoma could explain the expansive growth and could serve as future drug target, as for example also suggested for psoriasis.

OBJECTIVE

The aim of this study was to analyze and compare the cytokine profiles of cholesteatoma and the surrounding tissues.

METHODS

The Luminex Multiplex xMAP bead-based antibody assay was applied to measure the concentrations of 44 cytokines, chemokines, and growth factors (BIRC5, CCL11, CCL2, CCL3, CCL4, CCL5, CCL7, CD40LG, CSF2, CSF3, CX3CL1, CXCL10, CXCL9, EGF, HGF, ICAM1, IFNA2, IFNG, IL10, IL12*, IL12B, IL13, IL15, IL17A, IL17F, IL1A, IL1B, IL1R1, IL2, IL20, IL21, IL22, IL23A, IL4, IL5, IL6, IL7, IL8, LTA, MIF, TGFA, TGFB1, TNF, VEGFA) in human biopsies from cholesteatoma, neck of cholesteatoma (the transition zone from tympanic membrane), tympanic membrane, external auditory canal skin, and middle ear mucosa.

RESULTS

All 44 cytokines were detected in all 5 tissue types. Compared with external auditory canal skin, cholesteatoma showed high levels of IL8 (ratio 38, p = 0.027) and IL-21 (ratio 4.1, p = 0.02) and low levels of IL-6 (ratio 0.07, p = 0.027).

Acquired cholesteatoma: summary of the cascade of molecular events

BACKGROUND

Cholesteatoma is considered a benign, gradually expanding and destructive epithelial lesion of the temporal bone. The pathogenesis of different classifications of cholesteatoma is marked by similar underlying cellular and molecular processes. Stepwise explanations of the histopathogenesis have been described previously. The current paper focuses on expounding the molecular events of cholesteatoma.

METHOD AND RESULTS

Cholesteatoma pathogenesis encompasses a complex network of signalling pathways during: epidermal hyperplasia, perimatrix-matrix interactions and mucosal disease. This paper presents a review of the molecular events driven by inflammatory mediators and enzymes during: cholesteatoma growth (cell proliferation and apoptosis); maintenance and deterioration (angiogenesis and hypoxia, oxidative stress and toxicity); and complications (bone erosion and hearing loss). The cascade of molecular events applicable to atelectasis and cholesteatoma that coexist with chronic otitis media and bone erosion as sequelae is summarised.

CONCLUSION

The role of lipids in this disease is relatively unexplored, but there is evidence in support of fatty acid role-players that needs confirmation. Future directions in lipid research to delineate molecular mechanisms are proposed.