Neutrophils In Areas Research Articles

IL-26 in the Lung and Its Role in COPD Inflammation.

IL-26 is a cytokine expressed by infiltrating pro-inflammatory IL-17-producing T cells in the tissues of patients with chronic lung inflammation. IL-26 induces the chemotactic response of human neutrophils to bacteria and other inflammatory stimuli. In recent years, the innovative properties of IL-26 have been described. Studies have shown that, as DNA is released from damaged cells, it binds to IL-26, which plays the role of a carrier molecule for extracellular DNA, further contributing to its binding to the site of inflammation. This mechanism of action indicates that IL-26 may serve both as a driver as well as a stimulus of the inflammatory process, leading to the installation of a noxious amplification loop and, eventually, persistent inflammation. IL-26 also demonstrates direct antimicrobial effects derived from its capability to create pores and disrupt bacterial membranes, as indicated by the presence of membrane blebs on the surface of the bacteria and cytosolic leakage pores in bacterial walls, produced in response to microbial stimuli in human airways by several different immune and structural cells. Surprisingly, while this particular cytokine induces the gathering of neutrophils in areas of infection, it also exhibits inhibitory and pro-inflammatory effects on airway epithelial and immune cells. These remarkable effects underline the necessity of a better understating of its biological behavior and its role in the pathophysiology and disease burden in several smoking-related airway inflammatory disorders, such as Chronic Obstructive Pulmonary Disease (COPD) and chronic bronchitis. In this review, we aim to discuss the current role of IL-26 in the lung, with an emphasis on systemic inflammation in patients suffering from COPD and chronic bronchitis.

OP15 A new simplified histology artificial intelligence system for accurate assessment of remission in Ulcerative Colitis

Abstract Background Histological remission (HR) is evolving as a treatment target in ulcerative colitis (UC). Several histological indices have been developed, however, their widespread adoption beyond clinical trials is limited by practical difficulties and interobserver variability. Furthermore, the relative complexity of available scores hinders the development of an AI algorithm. We aimed to develop a simple histologic index, aligned to endoscopy, and apply it to a computer-aided diagnosis (CAD) system to evaluate HR. Methods 614 digitalised biopsies (WSI) from 307 UC patients enrolled into a prospective multicentre study1 were analysed. First, the simple PICASSO Histologic Remission Index (PHRI) based only on the presence of neutrophils, was developed and validated by expert pathologists. Table 1 To implement PHRI in a CAD system we designed a semi-supervised inductive transfer learning strategy composed of two modules. The first consists of a novel deep learning strategy based on a convolutional neural network architecture. This detected neutrophils in areas (patches) of a subset of 314 biopsies (172 remission, 142 active), in 158 of which the presence of neutrophils had been meticulously annotated at pixel level. WSI were then divided in training (172), validation (47), and testing sets (95). Following a multiple instance learning paradigm, a second model combined the features of all patches of each biopsy into a dichotomous result: presence/absence of disease activity. Figure 1 and 2. Finally, we compared the AI prediction with the pathologists’ assessment. Results PHRI correlated strongly with all endoscopic scores (MES, UCEIS and PICaSSO) of the same bowel areas (rectum and sigmoid) (Spearman’s ρ= 0.55 to 0.78). Inter-reader agreement between pathologists was almost perfect (ICC 0.84). In the validation and testing sets our model predicted the presence of neutrophils respectively with 61% and 72% sensitivity, 98% and 84% specificity, 93% and 75% positive predictive value (PPV), and 86% and 83% negative predictive value (NPV) respectively (Table 2). When predicting remission in whole biopsies, in the validation cohort the AI system had 65% sensitivity, 93% specificity, 86% PPV, and 78% NPV. In the testing cohort the same metrics were 62%, 94%, 90%, and 73% (Table 2). Conclusion PHRI is the simplest histological index in UC and correlates strongly with endoscopic activity. Based on PHRI we developed the first artificial intelligence model able to accurately predict histological remission in biopsies of UC. This tool can effectively expedite, support, and standardise the histological assessment of UC in clinical practice. Reference 1. Iacucci et al. Gastroenterology 2021

Estimating the time of skeletal muscle contusion based on the spatial distribution of neutrophils: a practical approach to forensic problems.

The study aimed to explore the neutrophil's spatial distributions used to estimate the histological age of contused skeletal muscle, and assessed the accuracy of various indicators, such as the proportion of neutrophils, "neutrophil mean distance," and distribution of neutrophils in areas of "contiguous contour lines." Fifty-five Sprague-Dawley rats were divided randomly into a control group and contusion groups at 1, 1.5, 2, 3, 4, and 6h, as well as 1, 3, 5, and 15days, post-injury (n = 5 per group). Nuclei and neutrophils were detected by hematoxylin and eosin (HE) staining and immunohistochemical (IHC) staining. At 0-24h after injury, the distribution of neutrophils at distances of 100, 200, 300, 400, 500, and 600µm from adjacent blood vessels was determined, and the best samples were screened to estimate wound age. To estimate wound age as accurately as possible, Fisher discriminant analysis (FDA) of the proportion of neutrophils, neutrophil mean distance, and distribution of neutrophils was performed, and 100.0% and 95.0% of the original and cross-validated cases were correctly classified, respectively. The spatial distribution of neutrophils at different distances from adjacent blood vessels showed a strong correlation with the histological age of contusion skeletal muscle, and the combination of the proportion of neutrophils, neutrophil mean distance, and distribution of neutrophils could be used to accurately estimate wound age.

PTU-130 Regulatory T Cells In Acute Liver Failure Are Functionally Intact And May Contribute To Retention Of Neutrophils In Areas Of Hepatic Necrosis

IntroductionAcute liver failure (ALF) is a sterile inflammation with a high mortality. The immunological response to acute liver injury is initiated by the infiltration of innate neutrophils and is followed...

Human mucosal leishmaniasis: Neutrophils infiltrate areas of tissue damage that express high levels of Th17‐related cytokines

Mucosal leishmaniasis (ML) is characterised by severe tissue destruction. Herein, we evaluated the involvement of the IL-17-type response in the inflammatory infiltrate of biopsy specimens from 17 ML patients. IL-17 and IL-17-inducing cytokines (IL-1β, IL-23, IL-6 and TGF-β) were detected by immunohistochemistry in ML patients. IL-17(+) cells exhibited CD4(+), CD8(+) or CD14(+) phenotypes, and numerous IL-17(+) cells co-expressed the CC chemokine receptor 6 (CCR6). Neutrophils, a hallmark of Th17-mediated inflammation, were regularly detected in necrotic and perinecrotic areas and stained positive for neutrophil elastase, myeloperoxidase and MMP-9. Taken together, these observations demonstrate the existence of Th17 cells in ML lesions associated with neutrophils in areas of tissue injury and suggest that IL-17 is involved in ML pathogenesis.

Distinct expression patterns and levels of enzymatic activity of matrix metalloproteinases and their inhibitors in primary brain tumors.

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) have been implicated in the immense invasive potential and neovascularization of primary brain tumors. We investigated the gene expression profiles of MMPs 1, 2, 3, 7, 9, 12, 13, 14, 16 and of TIMPs 1, 2, 3, and 4 in various primary brain tumors (astrocytoma WHO grade I-III, glioblastoma, PNET, ependymoma III and oligoastrocytoma II) using novel RNase protection assay probe sets. In addition, we determined the level and cellular source of gelatinolytic activity and localized gelatinase B and TIMP-1 RNA. Distinct expression patterns of the MMP and TIMP genes were found in the various brain tumors tested. While the WHO grade I and II tumors had MT1/MT3 ratios below 1, the malignant (grade III and IV) tumors had ratios above 1. Strong expression of TIMP-1 RNA was observed in all malignant tumors and in grade I pilocytic astrocytomas and localized to the walls of neovessels. Quantitative analysis of enzymatic activity in the soluble fraction of protein extracts revealed that in most tumors gelatinases remained in the inactive pro-form. In situ zymography revealed net gelatinolytic activity in neurons of normal brain and in tumor cells and vessel walls of all tumors tested. Immunohistochemistry demonstrated that gelatinase B was localized to vessel walls, to neutrophils in areas of hemorrhage, and in glioblastomas to macrophages. Together these data demonstrate that the different primary brain tumors show distinct regulation of MMP and TIMP genes. The localization of the soluble gelatinase B indicates an association with neovascularization, whereas membrane-bound MMPs may account for the invasive potential of the glial tumor cells.

U83836E reduces secondary brain injury in a rabbit model of cryogenic trauma.

Oxygen-derived free radicals have been implicated in secondary brain injury after head trauma. Although oxygen-free radicals may be derived from multiple sources, the activation and accumulation of neutrophils in areas of brain injury is a potential source of deleterious inflammatory mediators, including free radicals, which may exacerbate the primary insult. Neutrophils may also impede the cerebral microcirculation by congestion and occlusion of postcapillary venules. The lazaroid U83836E is a potent-free radical scavenger that inhibits lipid peroxidation. U83836E was studied in a cryogenic model of cerebral injury in pretreatment paradigm. Fifteen rabbits received a unilateral cryogenic brain lesion. Six animals received U83836E, and nine animals received vehicle only. Arterial blood gases, hematocrit, temperature, and mean arterial pressure were controlled in physiologic range throughout the experiment. Intracranial pressure was continuously monitored. Lesion size was determined by triphenyltertrazolium chloride staining and planimetric image analysis. Neutrophil aggregation and oxygen-free radical generation was assessed in whole blood by impedance aggregometry and simultaneous luminol-mediated chemiluminescence, respectively. Myeloperoxidase assay was used to determine neutrophil accumulation within the brain. Elevations in intracranial pressure from baseline values were significantly greater in the untreated (control) animals at all time points (p < 0.0001). Mean lesion size (% hemisphere +/- SEM) was significantly reduced in animals receiving U83836E (4.41 +/- 0.64, n = 6) when compared with controls (15.09 +/- 2.28, n = 9, p < 0.001). A reduction in both the release of oxygen-free radicals and in neutrophil aggregation following the cryogenic injury in the U83836E animals correlated with a smaller lesion volume.(ABSTRACT TRUNCATED AT 250 WORDS)