Correlation Between Proinflammatory Cytokine Expression and Clinical Data in Apical Granuloma.

INTRODUCTION: This study was intended to evaluate the expression of inflammatory cytokines commonly secreted by CD4+ T cells (IL-2, IL-5, IL-17, TGF-ß, TNF-α, and IFN-γ) in apical granulomas and correlate with the clinical conditions and time elapsed since root canal treatment. METHODS: Eighteen biopsy specimens obtained by periradicular surgery of teeth with post-treatment apical periodontitis and diagnosed as apical granuloma were available from the oral pathology laboratory. Silanized slides containing paraffin sections were used for immunohistochemical reactions. Images were analyzed by using an optical microscopy and each slide was subdivided into 5 fields at high magnification. RESULTS: IFN-γ and TGF-ß were the cytokines with the highest expression levels. There were statistically significant differences when comparing IL-2 and IFN-γ (P < .05), and IL-2 and TGF-ß (P < .05). Comparison between the detected cytokines and clinical data and time of treatment demonstrated significant correlation (P < .05) between lower expression of IL-2 and the presence of painful symptoms, absence of sinus tract, and treatments performed more than 4 years before. It was also possible to observe a significant correlation between lower expression of IL-5 and treatments performed less than 4 years before (P < .05). CONCLUSION: IFN-γ and TGF-ß were highly expressed in apical granulomas. However, only IL-2 and IL-5 levels were associated with clinical data and time since previous root canal treatment.

Utility of Ultrasonography for Diagnosing and Differentiating Periapical Granuloma from Radicular Cyst.

RATIONALE AND OBJECTIVES: This study aimed to investigate the reliability and accuracy of high-resolution ultrasonography (US) for diagnosing periapical lesions and differentiating radicular cysts from granulomas. MATERIALS AND METHODS: This study included 109 teeth with periapical lesions of endodontic origin from 109 patients scheduled for apical microsurgery. Ultrasonic outcomes were analyzed and categorized after thorough clinical and radiographic examinations using US. B-mode US images reflected the echotexture, echogenicity, and lesion margin, while color Doppler US assessed the presence and features of blood flow of interested areas. Pathological tissue samples were obtained during apical microsurgery and subjected to histopathological examination. Fleiss' κ was used to measure interobserver reliability. Statistical analyses were performed to assess the diagnostic validity and the overall agreement between US and histological findings. The reliability of US compared to histopathological examinations was assessed based on Cohen's κ. RESULTS: The percent accuracy of US for diagnosing cysts, granulomas, and cysts with infection based on histopathological findings was 89.9%, 89.0%, and 97.2%, respectively. The sensitivity of US diagnoses was 95.1% for cysts, 84.1% for granulomas, and 80.0% for cysts with infection. The specificity of US diagnoses was 86.8% for cysts, 95.7% for granulomas, and 98.1% for cysts with infection. The reliability for US compared to histopathological examinations was good (κ = 0.779). CONCLUSION: The echotexture characteristics of lesions in US images correlated with their histopathological features. US can provide accurate information on the nature of periapical lesions based on the echotexture of their contents and the presence of vascularity. It can help improve clinical diagnosis and avoid overtreatment of patients with apical periodontitis.

A deep learning approach for radiological detection and classification of radicular cysts and periapical granulomas.

OBJECTIVES: Dentists and oral surgeons often face difficulties distinguishing between radicular cysts and periapical granulomas on panoramic imaging. Radicular cysts require surgical removal while root canal treatment is the first-line treatment for periapical granulomas. Therefore, an automated tool to aid clinical decision making is needed. METHODS: A deep learning framework was developed using panoramic images of 80 radicular cysts and 72 periapical granulomas located in the mandible. Additionally, 197 normal images and 58 images with other radiolucent lesions were selected to improve model robustness. The images were cropped into global (affected half of the mandible) and local images (only the lesion) and then the dataset was split into 90% training and 10% testing sets. Data augmentation was performed on the training dataset. A two-route convolutional neural network using the global and local images was constructed for lesion classification. These outputs were concatenated into the object detection network for lesion localization. RESULTS: The classification network achieved a sensitivity of 1.00 (95% C.I. 0.63-1.00), specificity of 0.95 (0.86-0.99), and AUC (area under the receiver-operating characteristic curve) of 0.97 for radicular cysts and a sensitivity of 0.77 (0.46-0.95), specificity of 1.00 (0.93-1.00), and AUC of 0.88 for periapical granulomas. Average precision for the localization network was 0.83 for radicular cysts and 0.74 for periapical granulomas. CONCLUSIONS: The proposed model demonstrated reliable diagnostic performance for the detection and differentiation of radicular cysts and periapical granulomas. Using deep learning, diagnostic efficacy can be enhanced leading to a more efficient referral strategy and subsequent treatment efficacy. CLINICAL SIGNIFICANCE: A two-route deep learning approach using global and local images can reliably differentiate between radicular cysts and periapical granulomas on panoramic imaging. Concatenating its output to a localizing network creates a clinically usable workflow for classifying and localizing these lesions, enhancing treatment and referral practices.

The Paradigm of the Inflammatory Radicular Cyst: Biological Aspects to be Considered.

Inflammatory radicular cysts (IRCs) are chronic lesions that follow the development of periapical granulomas (PGs). IRCs result from multiple inflammatory reactions led initially by several pro-inflammatory interleukins and growth factors that provoke the proliferation of epithelial cells derived from epithelial cell rests of Malassez present in the granulomatous tissue, followed by cyst formation and growth processes. Multiple theories have been proposed to help explain the molecular process involved in the development of the IRC from a PG. However, although multiple studies have demonstrated the presence of epithelial cells in most PGs, it is still not fully understood why not all PGs turn into IRCs, even though both are stages of the same inflammatory phenomenon and receive the same antigenic stimulus. Histopathological examination is currently the diagnostic gold standard for differentiating IRCs from PGs. Although multiple studies have evaluated the accuracy of non-invasive or minimally invasive methods in assessing the histopathological nature of the AP before the intervention, these studies' results are still controversial. This narrative review addresses the biological insights into the complex molecular mechanisms of IRC formation and its histopathological features. In addition, the relevant inflammatory molecular mediators for IRC development and the accuracy of non-invasive or minimally invasive diagnostic approaches are summarised. (EEJ-2022-03-041).

Elevated Foxo3a and Fas-ligand expression in human periapical granulomas as a potential treatment target.

OBJECTIVE: Periapical granuloma is a common periodontitis type involving chronic inflammation; however, the efficacy of current therapies is limited. Its molecular pathogenesis also remains obscure. Forkhead box transcription factor class o3a (Foxo3a) and Fas-ligand (FasL) are associated with chronic inflammation. Therefore, in this study, we aimed to clarify the roles of Foxo3a and FasL in periapical granuloma pathophysiology. SUBJECTS AND METHODS: Periapical lesions were obtained from patients during endodontic surgery and tooth extraction; those diagnosed with periapical granulomas using haematoxylin and eosin staining were further analysed. Immunohistochemical analysis was performed for Foxo3a and FasL, and real-time polymerase chain reaction was performed for FOXO3A, FASL and interleukin (IL)-1ß. Healthy gingival tissues were also examined as controls. RESULTS: Neutrophils, lymphocytes and plasma cells in the periapical granulomas, but not healthy tissues, expressed Foxo3a. Dual-colour immunofluorescence imaging revealed Foxo3a and FasL co-expression in leukocytes. FOXO3A, FASL and IL-1ß mRNA levels in healthy gingival tissues were significantly lower than those in the periapical granulomas. Additionally, FOXO3A and IL-1ß expressions were negatively correlated. CONCLUSIONS: Phosphorylated Foxo3a may reduce IL-1ß release by inhibiting apoptosis through FasL in periapical periodontitis and prevent exacerbation. Thus, Foxo3a is a potential therapeutic agent for periapical periodontitis.

The Potential Immunomodulatory Roles of Semaphorin 4D in Human Periapical Lesions.

INTRODUCTION: Semaphorin 4D (SEMA4D) is an important immunoregulator in the development of inflammatory diseases. Currently, the role of SEMA4D in human apical periodontitis remains unclear. This study aims to investigate the expression of SEMA4D and its potential immunomodulatory roles in apical periodontitis. METHODS: A total of 31 periapical tissues and 6 healthy gingival tissues were used in this experiment. Hematoxylin-eosin staining, immunohistochemical staining, and multiplex immunofluorescence staining were performed for histologic examination and immunochemical analysis. For data processing, the number of SEMA4D+, CD4+, CD8+, and CD20+ cells was analyzed by QuPath. In addition, the colocalization of SEMA4D with CD4, CD8, and CD20 was detected. RESULTS: Radicular cysts (RCs) (n = 18) and periapical granulomas (PGs) (n = 13) were identified by histologic evaluation. The number of SEMA4D+ cells in PGs was significantly greater than that in RCs (P < .05). T-cell and B-cell infiltration did not differ significantly between RCs and PGs. An increased number of CD20+ cells was observed in both types of apical periodontitis compared to CD8+ cells and CD4+ cells. Additionally, the presence of SEMA4D/CD4 and SEMA4D/CD20 double-positive cells was also markedly higher in PGs than in RCs. CONCLUSION: The expression of SEMA4D and related immune cells showed different characteristics between RCs and PGs. The disparate expression patterns indicated the possible different pathologic states of the 2 types of periapical lesions. This study provides a new perspective on the description of the comprehensive microenvironment of periapical lesions.

Imunoexpressão de ING 4, VEGF e NF-κB em lesões periapicais inflamatórias / Immunoexpression of ING 4, VEGF and NF-κB in inflammatory periapical lesions

As lesões periapicais inflamatórias (LPIs) são condições patológicas decorrentes de infecções de origem odontogênica, principalmente representadas pelos granulomas periapicais (GPs) e cistos radiculares (CRs). Sua patogênese está associada a mecanismos imunológicos e angiogênicos. O presente estudo, do tipo retrospectivo, teve como objetivo analisar, de forma semiquantitativa, a expressão imuno-histoquímica de ING-4, VEGF e NF-κB em LPIs, e correlacionar o padrão de expressão dessas proteínas. A amostra consistiu de 26 GPs, 17 CRs e 19 cistos radiculares residuais (CRRs). Foram avaliados espessura epitelial e infiltrado inflamatório, e a associação desses achados com o padrão de expressão das proteínas ING-4, VEGF e NF-κB nas LPIs selecionadas. Para a realização da análise estatística, foram utilizados os testes de qui-quadrado, Kruskal-Wallis, Mann-Whitney e correlação de Spearman (p < 0,05). O infiltrado inflamatório exibiu maior intensidade no GP, seguido pelo CR, e por último, o CRR (p < 0,05). Apesar de não haver associação estatisticamente significativa ao associar a expressão de ING-4 nas células inflamatórias do tecido conjuntivo ou cápsula fibrosa entre os grupos de LPIs, o GP e CR evidenciaram, através da média de postos, maior expressão dessa proteína. Não foi evidenciada associação estatisticamente significativa de ING-4 com a intensidade do infiltrado inflamatório. A imunoexpressão de VEGF no núcleo das células inflamatórias do tecido conjuntivo ou cápsula fibrosa exibem associação significativa com as LPIs, que ocorre maior expressão dessa proteína nos cistos (p= 0,002). A maior expressão de NF-κB foi evidenciada nos casos de GPs, tanto a nível nuclear quanto citoplasmático das células inflamatórias (p = 0,005; p = 0,002). Não houve associação estatisticamente significativa quando comparada a expressão de NF-κB entre os cistos, mas a mediana da expressão dessa proteína foi maior para os CRs. Na cápsula fibrosa, a imunoexpressão nuclear e citoplasmática de NF-κB nas células inflamatórias foi superior nas lesões periapicais com intenso infiltrado inflamatório (p < 0,001). Portanto, sugere-se que ING-4, VEGF e NF-κB participam do desenvolvimento das LPIs, e apesar de ocorrer relação diretamente proporcional entre a expressão dessas proteínas, ING-4 não exerceu atividade reguladora na inflamação associada a essas lesões (AU).

Inflammatory periapical lesions (IPLs) are pathological conditions resulting from infections of odontogenic origin, being mainly represented by periapical granulomas (PGs) and radicular cysts (RCs). Its pathogenesis is associated with immunological and angiogenic mechanisms. This retrospective study, semi-quantitative and comparative aimed to analyze the immunohistochemical expression of ING-4, VEGF and NF-κB in IPLs, and to correlate the pattern of expression of these proteins. The sample consisted of 26 were PGs, 17 RCs and 19 residual radicular cysts (RRCs). Epithelial thickness and inflammatory infiltrate were evaluated, and the correlation of these findings with the expression pattern of ING-4, VEGF and NF-κB proteins in selected IPLs. To perform the statistical analysis, the chi-square, Kruskal-Wallis, Mann-Whitney and Spearman correlation tests were used (p < 0.05). The inflammatory infiltrate exhibited greater intensity in the PG, followed by the RC, and finally, the RRC (p < 0.05). Although there was no statistically significant association when associating the expression of ING-4 in inflammatory cells of the connective tissue or fibrous capsule the groups of IPLs, the PG and RC showed higher expression of this protein. There was no statistically significant association between ING-4 and the intensity of the inflammatory infiltrate. Immunoexpression of VEGF in the nucleus of inflammatory cells in the connective tissue or fibrous capsule shows a significant association with IPLs, in which there is greater expression of this protein occurring in cysts (p= 0,002). The highest expression of NF-κB was evidenced in cases of PGs, both at the nuclear and cytoplasmic level of inflammatory cells (p=0,005; p= 0,002). There was no statistically significant association when comparing the expression of NF-κB between the cysts, but the median expression of this protein was expression was higher for the RCs. In the fibrous capsule, nuclear and cytoplasmic NF-κB immunoexpression in inflammatory cells was higher in periapical lesions with intense inflammatory infiltrate (p<0.001). Therefore, it is suggested that ING-4, VEGF and NF-κB participate in the etiopathogenesis of IPLs, and that there is a directly proportional relationship between the expression of these proteins. ING-4 did not exert regulatory activity in the inflammation associated with these lesions (AU).

Prevalence of Nonendodontic Diagnoses in Periapical Biopsies: A 6-year Institutional Experience.

INTRODUCTION: The purpose of this study was to identify nonendodontic periapical lesions (NPLs) mimicking endodontic pathosis, which are most frequently encountered by clinicians. METHODS: A retrospective study was conducted on biopsies obtained from 2015-2020 at Texas A&M College of Dentistry's oral pathology laboratory. The online database was screened for cases submitted as suspected endodontic pathology using specific key words. Histologic diagnoses were collected to determine the prevalence of NPLs that were originally thought to be of endodontic origin. The frequency and percentage of endodontic pathology and NPLs were documented. RESULTS: Among 6704 biopsies clinically diagnosed as endodontic lesions, 190 (2.8%) were histopathologically diagnosed as NPLs. The most frequent NPLs were odontogenic keratocytes' (n = 70, 36.8%), cemento-osseous dysplasia (n = 27, 14.2%), and dentigerous cysts (n = 22, 11.6%). Of all NPLs, 3.7% were malignant neoplasms, with the most common diagnosis being squamous cell carcinoma. Of 6514 endodontic histologic diagnoses, the prevalence of periapical granulomas and cysts was 60.2% (n = 3924) and 39.1% (n = 2549), respectively. CONCLUSIONS: Although most endodontic submissions are likely to be histologically diagnosed as periapical granulomas or cysts, the clinician should be aware that a small portion of these lesions may be nonendodontic in origin and possibly neoplastic in nature. Histopathologic evaluation of biopsied specimens is critical to achieve a proper diagnosis to ensure the appropriate management of patients.

Release of Matrix Metalloproteinases by Macrophages in Radicular Cysts and Residual Radicular Cysts.

INTRODUCTION: Radicular cysts (RCs) and residual radicular cysts (RRCs) are the sequelae of dental caries and that leads to proliferation of epithelial rests of Malassez in periapical tissues. OBJECTIVES: The aim was to evaluate the relationship between Langerhans cells, macrophages, matrix metalloproteinases (MMP-9, MMP-13), and tumor necrosis factor-alpha (TNF-α) in the capsule and lining epithelium of cystic lesions. MATERIALS AND METHODS: Twenty RCs and 20 RRCs were submitted to immunohistochemical analysis with anti-CD68, anti-CD1a, anti-MMP-9, anti-MMP-13, and anti-TNF-α antibodies. The Mann-Whitney test and the Spearman correlation test were used for analysis of the data (P<0.05). RESULTS: The immunoexpression of MMP-13 and CD68 was significantly higher in RCs when compared with RRCs (P=0.011 and 0.012, respectively). The presence of an intense inflammatory infiltrate was significantly correlated with the immunoexpression of CD68 in RCs (P=0.025). Expression of CD68 showed a significant positive correlation with MMP-13 (P=0.015). A moderate correlation was observed between MMP-9 and MMP-13 (P=0.010). TNF-α expression was more common in RCs (P=0.001). CD1a was more frequently expressed in atrophic epithelium (P=0.041) and was significantly correlated with TNF-α (P=0.014). CONCLUSION: Langerhans cells induce a greater release of TNF-α which, in turn, is responsible for the stimulation of M1 macrophages. Higher immunoexpression of MMP-13 and MMP-9 is observed in the early stages of RCs compared with RRCs. Therefore, the toxins of microorganisms present in highly inflamed RCs are the main factors triggering a proinflammatory immune response and greater cystic expansion in the early stages of these lesions.

Immunocolocalization of Interferon Regulatory Factory 5 with Tumor Necrosis Factor Receptor-associated Factor 6 and AKT2 in Human Apical Periodontitis.

INTRODUCTION: Interferon regulatory factor 5 (IRF5) is critical for the regulation of immune and inflammatory responses in health and diseases. However, the presence of IRF5 in human apical periodontitis remains unknown. This study aimed to explore the expression and colocalization of IRF5 with tumor necrosis factor receptor-associated factor 6 (TRAF6) and AKT2 in human apical periodontitis. METHODS: A total of 39 human periapical tissues, including healthy gingival tissues (n = 12), periapical granulomas (PGs, n = 13), and radicular cysts (RCs, n = 14), were used in this study. The inflammatory infiltrates of lesions were evaluated by hematoxylin-eosin staining. The expression of IRF5 was detected by immunohistochemistry. Double immunofluorescence assessment was performed to colocalize IRF5 with CD68, TRAF6, and AKT2, respectively. Data were analyzed using the Kruskal-Wallis test. RESULTS: Immunohistochemistry revealed significantly higher expressions of IRF5 in PGs and RCs than the healthy control group. IRF5-CD68 double-positive cells were more predominant in RCs and PGs than the healthy control group. Significant differences of the IRF5-TRAF6 and IRF5-AKT2 double-positive cells were detected in periapical lesions compared with the healthy control tissues. CONCLUSIONS: IRF5 was highly expressed in macrophages of human periapical tissues and was colocalized with TRAF6 or AKT2 in human periapical tissues. These findings may provide new clues for understanding the pathogenesis of periapical diseases.

Expression of epithelial growth factors and of apoptosis-regulating proteins, and presence of CD57+ cells in the development of inflammatory periapical lesions.

OBJECTIVE: The mechanisms that stimulate the proliferation of epithelial cells in inflammatory periapical lesions are not completely understood and the literature suggests that changes in the balance between apoptosis and immunity regulation appear to influence this process.To evaluate the expression of the epidermal growth factor (EGF), its receptor (EGFR) and of the keratinocyte growth factor (KGF), the presence of CD57+ cells, the epithelial cell proliferation index, and the expression of the Bcl-2 protein in inflammatory periapical lesions (IPL) at different stages of development. METHODOLOGY: Our sample was composed of 52 IPLs (22 periapical granulomas - PG - and 30 periapical cysts - PC), divided into three groups: PGs, small PCs, and large PCs. Specimens were processed for histopathologic and immunohistochemical analyses. Sections were evaluated according to the amount of positive staining for each antibody. RESULTS: We found no significant differences among the groups regarding Bcl-2 (p=0.328) and Ki-67 (p>0.05) expression or the presence of CD57+ cells (p=0.748). EGF (p=0.0001) and KGF (p=0.0001) expression was more frequent in PCs than in PGs, and CD57+ cells were more frequent in IPLs with intense inflammatory infiltrates (p=0.0001). We found no significant differences in KGF (p=0.423), Bcl-2 (p=0.943), and EGF (p=0.53) expression in relation to inflammatory infiltrates or to the type of PC epithelial lining, but observed greater KGF expression (p=0.0001) in initial PCs. EGFR expression was similar among the groups (p>0.05). CONCLUSION: More frequent EGF and KGF expression in PCs and the greater presence of CD57+ cells in lesions with intense inflammatory infiltrates suggest that these factors influence IPL development. The greater KGF expression in initial PCs suggests its importance for the initial stages of PC formation.

Comparative Metabolomics Reveals the Microenvironment of Common T-Helper Cells and Differential Immune Cells Linked to Unique Periapical Lesions.

Periapical abscesses, radicular cysts, and periapical granulomas are the most frequently identified pathological lesions in the alveolar bone. While little is known about the initiation and progression of these conditions, the metabolic environment and the related immunological behaviors were examined for the first time to model the development of each pathological condition. Metabolites were extracted from each lesion and profiled using gas chromatography-mass spectrometry in comparison with healthy pulp tissue. The metabolites were clustered and linked to their related immune cell fractions. Clusters I and J in the periapical abscess upregulated the expression of MMP-9, IL-8, CYP4F3, and VEGF, while clusters L and M were related to lipophagy and apoptosis in radicular cyst, and cluster P in periapical granuloma, which contains L-(+)-lactic acid and ethylene glycol, was related to granuloma formation. Oleic acid, 17-octadecynoic acid, 1-nonadecene, and L-(+)-lactic acid were significantly the highest unique metabolites in healthy pulp tissue, periapical abscess, radicular cyst, and periapical granuloma, respectively. The correlated enriched metabolic pathways were identified, and the related active genes were predicted. Glutamatergic synapse (16-20),-hydroxyeicosatetraenoic acids, lipophagy, and retinoid X receptor coupled with vitamin D receptor were the most significantly enriched pathways in healthy control, abscess, cyst, and granuloma, respectively. Compared with the healthy control, significant upregulation in the gene expression of CYP4F3, VEGF, IL-8, TLR2 (P < 0.0001), and MMP-9 (P < 0.001) was found in the abscesses. While IL-12A was significantly upregulated in cysts (P < 0.01), IL-17A represents the highest significantly upregulated gene in granulomas (P < 0.0001). From the predicted active genes, CIBERSORT suggested the presence of natural killer cells, dendritic cells, pro-inflammatory M1 macrophages, and anti-inflammatory M2 macrophages in different proportions. In addition, the single nucleotide polymorphisms related to IL-10, IL-12A, and IL-17D genes were shown to be associated with periapical lesions and other oral lesions. Collectively, the unique metabolism and related immune response shape up an environment that initiates and maintains the existence and progression of these oral lesions, suggesting an important role in diagnosis and effective targeted therapy.

Inflammatory Response Mechanisms of the Dentine-Pulp Complex and the Periapical Tissues.

The macroscopic and microscopic anatomy of the oral cavity is complex and unique in the human body. Soft-tissue structures are in close interaction with mineralized bone, but also dentine, cementum and enamel of our teeth. These are exposed to intense mechanical and chemical stress as well as to dense microbiologic colonization. Teeth are susceptible to damage, most commonly to caries, where microorganisms from the oral cavity degrade the mineralized tissues of enamel and dentine and invade the soft connective tissue at the core, the dental pulp. However, the pulp is well-equipped to sense and fend off bacteria and their products and mounts various and intricate defense mechanisms. The front rank is formed by a layer of odontoblasts, which line the pulp chamber towards the dentine. These highly specialized cells not only form mineralized tissue but exert important functions as barrier cells. They recognize pathogens early in the process, secrete antibacterial compounds and neutralize bacterial toxins, initiate the immune response and alert other key players of the host defense. As bacteria get closer to the pulp, additional cell types of the pulp, including fibroblasts, stem and immune cells, but also vascular and neuronal networks, contribute with a variety of distinct defense mechanisms, and inflammatory response mechanisms are critical for tissue homeostasis. Still, without therapeutic intervention, a deep carious lesion may lead to tissue necrosis, which allows bacteria to populate the root canal system and invade the periradicular bone via the apical foramen at the root tip. The periodontal tissues and alveolar bone react to the insult with an inflammatory response, most commonly by the formation of an apical granuloma. Healing can occur after pathogen removal, which is achieved by disinfection and obturation of the pulp space by root canal treatment. This review highlights the various mechanisms of pathogen recognition and defense of dental pulp cells and periradicular tissues, explains the different cell types involved in the immune response and discusses the mechanisms of healing and repair, pointing out the close links between inflammation and regeneration as well as between inflammation and potential malignant transformation.

Macrophages subpopulations in chronic periapical lesions according to clinical and morphological aspects.

The aim of this study was to evaluate macrophage M1 and M2 subpopulations in radicular cysts (RCs) and periapical granulomas (PGs) and relate them to clinical and morphological aspects. M1 macrophages were evaluated by the percentage of CD68 immunostaining associated with the inflammatory cytokine TNF-α, and M2 macrophages, by its specific CD163 antibody. The CD68+/CD163+ ratio was adopted to distinguish between the two macrophage subpopulations. Clinical, radiographic, symptomatology, treatment, and morphological parameters of lesions were collected and a significance level of p = 0.05 was adopted for statistical analysis. The results showed that the CD68+/CD163+ ratio was higher in the RCs (median = 1.22, p = 0.002), and the highest TNF-α immunostaining scores were found in RCs (p = 0.018); in PGs, the CD68+/CD163+ ratio was lower and associated with a greater CD163+ immunostaining (median = 1.02, p <0.001). The TNF-α in cyst epithelium had a score of 3 in 10 cases and predominance of M1 macrophages by CD68+/CD163+ (median = 2.23). In addition, CD68+ cells had higher percentage of immunostaining in smaller RCs (p = 0.034). Our findings suggest that increased CD68 immunostaining associated with TNF-α cytokine in RCs results in a greater differentiation of the M1 phenotype. The higher CD163 immunostaining in PGs results in greater differentiation of the M2 phenotype. Therefore, the inflammatory state promoted by M1 macrophages is related to growth and progression of RCs; on the other hand, the immunomodulatory state of M2 macrophages is related to maintenance of PGs.

[Artigo Parcialmente Retratado] Prevalência da infecção por Helicobacter pylori em pacientes dispépticos e associação com fatores de riscos clínicos para o desenvolvimento de adenocarcinoma gástrico / [article partial retraction] prevalence of helicobacter pylori infection in dyspeptic patients and its association with clinical risk factors for developing gastric adenocarcinoma

ABSTRACT BACKGROUND: In Brazil, particularly in the underdeveloped localities, the prevalence of Helicobacter pylori (H. pylori) infections can range up to 90%. These rates are higher in older individuals and vary by country region. H. pylori infections are linked to the development of gastric pathologies, namely mild to moderate gastritis, gastroenteritis, peptic ulcer, intestinal metaplasia, and gastric cancer. In 1994, this organism was classified by the International Agency for Research on Cancer (IARC) as pertaining to the Group 1 carcinogen for gastric adenocarcinoma etiology. Gastric cancer represents a significant public health problem, being the fourth most common malignant tumor and the second largest cause of cancer-related deaths. OBJECTIVE: To investigate the prevalence of H. pylori infection in dyspeptic patients and determine the link between clinical risk factors and gastric adenocarcinoma diagnosis. METHODS: Polymerase chain reaction (PCR) analysis was employed for molecular diagnosis of gastric tissue biopsies collected from 113 dyspeptic patients at the University Hospital of Federal University of Goiás. Molecular analyses allowed the identification of H. pylori infections. Furthermore, histopathological examinations were performed to determine the clinical risks of developing gastric malignancies. RESULTS: The test results identified 69 individuals older than 44 years, from 75 (66.4%) positive H. pylori infection samples. The prevalence of gastric adenocarcinoma in this study was 1.3%. Among the infected patients, six (8.2%) had high risk, and 67 (91.8%) had a low risk of developing gastric cancer (P<0.05). CONCLUSION: This study shows a high prevalence of H. pylori infection and identifies its contribution to gastric inflammations, which in the long term are manifested in high-risk clinical factors for the development of gastric adenocarcinoma.

RESUMO CONTEXTO: No Brasil, particularmente nas áreas mais pobres, a prevalência da infecção por Helicobacter pylori pode variar até 90%. Esses índices aumentam com o envelhecimento da população e são distintos entre as diferentes regiões do país. Podendo manifestar diferentes sintomatologias, essa infecção está diretamente relacionada com o desenvolvimento de patologias gástricas como gastrite leve a moderada, gastroenterites, úlcera péptica, metaplasia intestinal e principalmente, o câncer gástrico. Em 1994 a bactéria foi categorizada pela International Agency for Research on Cancer (IARC) como carcinógeno do Grupo 1 para adenocarcinoma gástrico, tipo de câncer que representa um importante problema de saúde pública, sendo o quarto tumor maligno mais comum e a segunda maior causa de mortes por câncer no mundo. OBJETIVO: Analisar a prevalência da bactéria em pacientes dispépticos e avaliar a associação de fatores de risco clínicos para desenvolvimento de adenocarcinoma gástrico. MÉTODOS: Biópsias de tecido gástrico coletadas de 113 pacientes dispépticos, atendidos no Hospital das Clínicas da Universidade Federal de Goiás, foram submetidas a diagnóstico molecular por meio de Reação em Cadeia da Polimerase, para identificação da infecção por Helicobacter pylori, e exame histopatológico, para avaliar o risco clínico de desenvolvimento de adenocarcinoma gástrico. RESULTADOS: Foram diagnosticadas 75 (66,4%) amostras positivas para infecção por Helicobacter pylori, sendo 69 indivíduos maiores de 44 anos de idade. A prevalência do adenocarcinoma gástrico nesse estudo foi de 1,3% e dentre os pacientes positivos para a infecção bacteriana seis (8,2%) possuem alto risco e 67 (91,8%) baixo risco de desenvolver esse tipo de câncer (P<0,05). CONCLUSÃO: Esse estudo mostra uma alta prevalência da infecção por H. pylori na população estudada e identifica sua intrínseca contribuição para inflamações gástricas, que a longo prazo se manifestam em fatores clínicos de alto risco para o desenvolvimento de adenocarcinoma gástrico.

Macrophages subpopulations in chronic periapical lesions according to clinical and morphological aspects

Abstract: The aim of this study was to evaluate macrophage M1 and M2 subpopulations in radicular cysts (RCs) and periapical granulomas (PGs) and relate them to clinical and morphological aspects. M1 macrophages were evaluated by the percentage of CD68 immunostaining associated with the inflammatory cytokine TNF-α, and M2 macrophages, by its specific CD163 antibody. The CD68+/CD163+ ratio was adopted to distinguish between the two macrophage subpopulations. Clinical, radiographic, symptomatology, treatment, and morphological parameters of lesions were collected and a significance level of p = 0.05 was adopted for statistical analysis. The results showed that the CD68+/CD163+ ratio was higher in the RCs (median = 1.22, p = 0.002), and the highest TNF-α immunostaining scores were found in RCs (p = 0.018); in PGs, the CD68+/CD163+ ratio was lower and associated with a greater CD163+ immunostaining (median = 1.02, p <0.001). The TNF-α in cyst epithelium had a score of 3 in 10 cases and predominance of M1 macrophages by CD68+/CD163+ (median = 2.23). In addition, CD68+ cells had higher percentage of immunostaining in smaller RCs (p = 0.034). Our findings suggest that increased CD68 immunostaining associated with TNF-α cytokine in RCs results in a greater differentiation of the M1 phenotype. The higher CD163 immunostaining in PGs results in greater differentiation of the M2 phenotype. Therefore, the inflammatory state promoted by M1 macrophages is related to growth and progression of RCs; on the other hand, the immunomodulatory state of M2 macrophages is related to maintenance of PGs.

Histological and immunohistochemical study on the apical granuloma.

INTRODUCTION: Periapical granuloma is one of the most frequent periodontal pathology and belongs to the group named as apical periodontitis. MATERIALS AND METHODS: Out of 78 of diagnosed granulomas, we selected samples that we analyzed histologically and immunohistochemically. RESULTS: The histopathological aspect has been dominated by the presence of mononuclear cells of the lymphocyte and plasma cells type, showing the chronic aspect of the apical lesion. Also, we noticed that in the apical granuloma macrophages occur most often. This density of macrophages explains cellular and tissular disruption that occur in apical region of the tooth under the influence of bacterial flora that reached this area, as they have the role to phagocyte pathogens and cell and tissue residues that result from bacterial aggression. The reaction of the plasma cells, determined by their number, has been always associated with the age of the granulomas, and it is more intense in old, neglected granulomas, compared to recent granulomas. CONCLUSIONS: The number and type of immunity cells varies in the apical granuloma accordingly to the age of granuloma.

Epithelioid cell granuloma with caseating necrosis possibly caused by periapical periodontitis: a case report.

BACKGROUND: Epithelioid cell granuloma with caseating necrosis is a typical pathological finding in tuberculosis. While specific inflammation, including that related to tuberculosis, can induce caseating granuloma formation, there have been very few reports on the induction of caseating granuloma by non-specific inflammation. Chronic periapical periodontitis is usually related to bacterial biofilm formation as well as fungal or viral infection in the periapical lesion. However, it is difficult to eliminate these extraradicular pathogenic microbes by normal endodontic therapy alone, and more invasive surgical removal is almost always required. CASE PRESENTATION: Here we describe the case of a 30-year-old Japanese woman who had suffered from dull pain related to periapical periodontitis for approximately 10 years. Although the causal tooth had been previously extracted at the Department of Oral Surgery of another hospital in 2015, inflammation of the surrounding tissue had not abated. She was referred to our hospital in May 2016 and underwent surgical debridement via an intra/extraoral approach under general anesthesia. A caseating granuloma accompanied by a small amount of fungi was histopathologically confirmed in the excised specimen. Her inflammation has not been exacerbated since the operation. CONCLUSIONS: This is the first report in which non-specific inflammation is shown to induce caseating granuloma arising in the jaw. Our report also highlights the importance of sufficient root canal treatment during the first stage of the procedure.

Periodontitis apical: caracterización histológica y morfométrica de quistes radiculares y granulomas periapicales / Apical periodontitis: histological and morphometric characterization of radicular cysts and periapical granulomas

La periodontitis apical es una patología inflamatoria que afecta los tejidos periapicales de un diente desvitalizado. El objetivo de este estudio fue caracterizar histológica y morfométricamente las lesiones de quistes y granulomas utilizando microscopía óptica. Se analizaron seis biopsias obtenidas de dientes con indicación de exodoncia. El análisis histológico se realizó mediante microscopía óptica y microfotografías, con análisis de contraste de imágenes y conteo celular mediante ImageJ. Descripción de las características histológicas: en los quistes se observaron cavidades rodeadas de epitelio escamoso estratificado no queratinizado y una cápsula fibrosa compuesta de fibrocitos, fibroblastos e infiltrado inflamatorio crónico; en los granulomas se observaron capilares, una capsula fibrosa de fibrocitos/fibroblastos y un infiltrado inflamatorio de predominio linfocitario. Cuantificación del número celular de infiltrado inflamatorio: para quistes fue de 9,2 cel/10000 µm2, mientras que para granulomas fue de 20,8 cel/10000 µm2, sin diferencias estadísticas significativas entre ambos (p=0,654). Cuantificación del número celular de fibrocitos/fibroblastos: para quistes fue de 15,4 cel/10000 µm2, mientras que para granulomas fue de 18,5 cel/10000 µm2, sin diferencia estadística significativa (p=0,499). Porcentaje de colágeno tipo I: para los quistes fue de 37,8±19,2 %, mientras que para granulomas fue de 33,8±23,3 %, sin diferencias estadísticas significativas (p=0,704). Se observó una correlación negativa moderada para el infiltrado inflamatorio (R=0,637) y una correlación positiva baja para fibrocitos/fibroblastos (R=0,121), en relación a la cantidad de colágeno tipo I. Medición del área de las lesiones periapicales: el promedio total de las lesiones fue de 10,7±5,0 mm2, siendo el mayor tamaño un quiste de 18,1 mm2 y el menor un granuloma de 5,2 mm2. El análisis histológico permite realizar un diagnóstico diferencial de lesiones con características similares y así definir el tratamiento más adecuado.

Apical periodontitis is an inflammatory pathology that affects the periapical tissues of a devitalized tooth. The aim of this study was to histologically and morphometrically characterize lesions of cysts and granulomas using light microscopy. Six biopsies obtained from teeth with indication of exodontia were analyzed. The histological analysis was carried out by means of optical microscopy and microphotographs, with contrast analysis of images and cell count by ImageJ. A description of the histological characteristics was made, observing the cavities surrounded by stratified squamous non-keratinized epithelium and a fibrous capsule composed of fibrocytes, fibroblasts and chronic inflammatory infiltrate; in the granulomas, capillaries, a fibrous capsule of fibrocytes/fibroblasts and a predominantly lymphocytic inflammatory infiltrate were observed. In relation to quantification of the cellular number of inflammatory infiltrate, for cysts itwas of 9.2 cel / 10000 mm2, while for granulomas it was 20.8 cel / 10000 mm2, without significant statistical differences between both (p = 0.654). The quantification of the fibrocyte / fibroblast cell number was, for cysts, 15.4 cells / 10000 mm2, while for granulomas it was 18.5 cells / 10000 mm2, without significant statistical difference (p = 0.499). With respect to the percentage of collagen type I, for the cysts was 37.8 ± 19.2%, while for granulomas it was 33.8 ± 23.3%, without significant statistical differences (p = 0.704). A moderate negative correlation was observed for the inflammatory infiltrate (R = 0.667) and a low positive correlation for fibrocytes / fibroblasts (R = 0.121), in relation to the amount of type I collagen. Measurement of the area of the periapical lesions: the total average of lesions were 10.7 ± 5.0 mm2, the largest being a cyst of 18.1 mm2 and the smallest a granuloma of 5.2 mm2. The histological analysis allows to make a differential diagnosis of lesions with similar characteristics and thus define the most appropriate treatment.

Immunohistochemical Analysis of Cyclooxygenase-2 and Tumor Necrosis Factor Alpha in Periapical Lesions.

INTRODUCTION: The purpose of this study was to evaluate the expression of cyclooxygenase-2 (COX-2) and tumor necrosis factor alpha (TNF-α) in periapical granuloma (PG) and radicular cyst (RC) samples and to correlate it with the type of lesion, the intensity of the inflammatory infiltrate, and the thickness of the epithelial lining. METHODS: A total of 51 cases of periapical lesions (25 PGs and 26 RCs) were subjected to morphologic analysis and immunohistochemical study. The anti-COX-2 and anti-TNF-α antibodies were applied using the immunoperoxidase technique. Data were analyzed by the Mann-Whitney test, Pearson chi-square test, Fisher exact test, and Spearman correlation. RESULTS: Analysis of the inflammatory infiltrate revealed that 80% of PGs exhibited a grade III infiltrate as opposed to a 19% rate in RCs (P < .001). Morphologic evaluation of the epithelial thickness of RCs revealed the presence of atrophic epithelium in 73% of cases. The majority of PGs had a score of 1 for COX-2 immunoexpression (n = 14, 54%) and a score of 2 for TNF-α expression (n = 16, 64%), whereas in cases of RCs a score of 1 was more prevalent for COX-2 and TNF-α expression (n = 17, 65%). Significant differences in the expression scores of COX-2 and TNF-α were detected in periapical lesions (P < .001). CONCLUSIONS: Based on these findings, we emphasize that RCs and PGs have a similar expression of inflammatory mediators (COX-2 and TNF-α) although the secretion of TNF-α by macrophages and of COX-2 by several cells was higher in PGs, indicating a greater inflammatory response in these lesions.