Absence Of Neutrophil Infiltration Research Articles

Automated Neutrophil Quantification and Histological Score Estimation in Ulcerative Colitis

Background and AimsIn the management of ulcerative colitis (UC), histological remission is increasingly recognized as the ultimate goal. The absence of neutrophil infiltration is crucial for assessing remission. This study aimed to develop an artificial intelligence (AI) system capable of accurately quantifying and localizing neutrophils in UC biopsy specimens to facilitate histological assessment. MethodsOur AI system, which incorporates semantic segmentation and object detection models, was developed to identify neutrophils in hematoxylin-eosin-stained whole slide images. The system assessed the presence and location of neutrophils within either the epithelium or lamina propria and predicted components of the Nancy Histological Index (NHI) and the PICaSSO Histologic Remission Index (PHRI). We evaluated the system’s performance against that of experienced pathologists and validated its ability to predict future clinical relapse risk in patients with clinically remitted UC. The primary outcome measure was the clinical relapse rate, defined as a partial Mayo score of ≥3. ResultsThe model accurately identified neutrophils, achieving a performance of 0.77, 0.81, and 0.79 for precision, recall, and F-score, respectively. The system’s histological score predictions showed a positive correlation with the pathologists’ diagnoses (Spearman’s ρ = 0.68–0.80, P < .05). Among patients who relapsed, the mean number of neutrophils in the rectum was higher than in those who did not relapse. Furthermore, the study highlighted that higher AI-based PHRI and NHI scores were associated with hazard ratios increasing from 3.2 to 5.0 for evaluating the risk of UC relapse. ConclusionThe AI system’s precise localization and quantification of neutrophils proved valuable for histological assessment and clinical prognosis stratification.

Pathogenetic variants of sepsis in oncologicy practice

Introduction Over the past 30 years, sepsis has been an urgent interdisciplinary problem of modern medicine due to the increase in morbidity and a consistently high mortality rate. Patients of oncological hospitals have a high predisposition to the development of sepsis, both in the postoperative period and in the departments of chemo and radiation therapy. In addition, sepsis may be a complication of the postoperative period in patients undergoing surgical treatment. Of interest is not only the clinical and laboratory diagnosis of sepsis in this category of patients, but also the features of its morphological picture, due to uniform diagnostic criteria. The greatest difficulties arise in the study of autopsies, after antitumor chemotherapy, which causes a secondary immunodeficiency condition characterized by the absence of a classical morphological picture of sepsis. The use of modern antibacterial drugs, as well as pathogenetic therapy of sepsis also leads to its pathomorphosis, which also complicates diagnosis.The aim of the study is to systematize the literature data and the results of our own research on the features of morphological manifestations of sepsis in oncological pathology, depending on cancer treatment.Material and methods The search and selection of literary sources was carried out in PubMed, GoogleScholar, electronic library systems elibrary.ru, the search depth is 30 years.Results and Discussion Sepsis in cancer patients after surgical interventions is characterized by hyperergic type of tissue reactions with hyperplasia of lymphoid and myeloid tissue and classic manifestations of septicopyemia of varying severity of purulent metastatic process: from macroscopically distinguishable abscesses to mini-foci of purulent inflammation. Against the background of antibiotic therapy, there is a pathomorphosis of sepsis with a predominance of microcirculation disorders and small focal ulcers. In patients after chemotherapy, accompanied by leukopenia and agranulocytosis, with sepsis, hypoplasia of myeloid and lymphoid tissue is noted, and in the internal organs, along with microcirculation disorders, foci of necrosis, severe dystrophic changes with the absence of neutrophil infiltration are found.Conclusion Sepsis in cancer patients from pathogenetic positions is heterogeneous, depending on the characteristics of the body and the nature of treatment, it should be divided into hyper- and anergic. The diagnosis of sepsis is clinico-morphological, which requires not only the use of clinical and laboratory diagnostic scales, but also the definition of criteria for morphological diagnosis.

DOP06 Histologic activity in Ulcerative Colitis patients achieving endoscopic healing is associated with higher rate of relapse and a distinct mucosal microbial and transcriptional profile

Abstract Background Histologic remission (HR) in ulcerative colitis (UC) has been associated with better clinical outcomes. However, this therapeutic target is hard to achieve with the available medications. We aim to assess the relapse-free survival (RFS) of patients with persistent histologic activity (HA) upon achieving endoscopic healing (EH) and the microbial and molecular signatures associated with this condition. Methods Left-sided and extensive UC patients and healthy controls (HC) were recruited at colonoscopy and sigmoid colon (SC) biopsy samples were obtained for HA evaluation, 16S rRNA sequencing and host RNA-seq. EH was defined as Mayo endoscopic subscore (MES) 0–1, and HA and histologic remission (HR) as the presence and absence of neutrophil infiltration, respectively. UC relapse was retrospectively evaluated and defined as symptomatic and endoscopic worsening. Cumulative RFS was assessed by log-rank test. Principal component analysis (PCA) was used for capturing cluster structure. For differential expressed genes (DEG) and enrichment pathway analyses, glmQLFTest in EdgeR and enrichKEGG in clusterProfiler were applied, respectively. Genes with log fold change &amp;gt; 2 and a log count per million &amp;gt; 1 were considered DEG. Dada2 algorithm in QIIME2 for amplicon sequence variant generation and ANCOM-BC package for differential abundance (DA) taxa analysis were applied. P-values of omics data were corrected by false discovery rate (FDR) method. Results Sixty-five UC patients had EH (37 MES 0 and 28 MES 1). Nine (20.9%) MES 0 and 17 (40.5%) MES 1 showed HA. Over a median follow-up of 4.2 years (IQR 2.6–6.1), UC patients with HA showed a significant lower RFS compared to HR (p &amp;lt; 0.05; Figure 1). This difference was not observed between MES 0 and MES 1 (p = 0.2). Transcriptomics data was available for 27 samples with HR and 9 samples with HA, as well as 43 HC and 13 MES 2–3 samples. PCA showed that HR and HA samples cluster with HC and MES 2–3 samples, respectively (Figure 2). Compared to HR, 163 DEG (118 up and 45 downregulated) were found in HA. Enrichment analysis showed significant upregulation of cytokine-cytokine interaction, Th17 and chemokine signaling pathways (Figure 3). Microbiome data was available for 43 and 19 samples with HR and HA, respectively. Three genera had significant DA in HA compared to HR (Figure 4). Conclusion HA in UC is better than MES at distinguishing a higher risk of relapse and has a transcriptomics profile closer to active endoscopic disease despite EH with significant upregulation of chemokine, cytokine and Th17 pathways. A different microbial signature is also observed in HA. These particular signatures could help to define strategies to reduce the risk of UC relapse in patients achieving EH.

Phototherapeutic hardening modulates systemic cytokine levels in patients with polymorphic light eruption

The etiopathogenesis of polymorphic light eruption (PLE) has been linked to impaired UV-immunosuppression, Langerhans cell (LC) retention, and an absence of neutrophil infiltration into UV-exposed PLE skin. We have previously shown that photohardening restores the impaired neutrophil responsiveness to the chemoattractants leucotriene B4 and formyl-methionyl-leucyl-phenylalanin in PLE patients. The aim of this study was to investigate whether photohardening modulates baseline chemokine and cytokine levels which would alter chemoresponsiveness and hence immune function in PLE patients. Sixteen PLE patients received photohardening therapy for 4-9 weeks by 311 nm UVB. Plasma samples were taken both before and within 48 h of the penultimate phototherapeutic exposure. Plasma from these 16 patients, 8 non-irradiated PLE patients, and 14 control subjects was analyzed for IL-1β, CXCL8 (IL-8), IL-10, IL-17, TNF, CCL2 (MCP-1), CCL5 (RANTES), CCL11 (eotaxin), and CCL22 (MDC). These cytokines and chemokines were measured in early spring (March to April) and again in late spring (April to June). PLE patients had a significantly elevated level of CCL11 (p = 0.003) and IL-1β (p = 0.002) in early spring (before phototherapy). In late spring, after phototherapy, PLE patients had significantly elevated CCL2 (p = 0.002) and TNF (p = 0.002) but a trend for lowered plasma levels of CXCL8 (p = 0.021). When comparing the cytokine shifts from early to late spring, while healthy controls and non-UV-irradiated PLE patients showed an increase, PLE patients undergoing photohardening exhibited a trend for decrease in IL-1β (p = 0.012). Taken together, our results indicate that photohardening may alter the complex cytokine milieu in PLE, in particular via IL-1β, helping to normalise the pathophysiologic response to subsequent UV exposure.

Endothelial nitric oxide synthase protects the post-ischemic liver: potential interactions with superoxide

Hepatic ischemia and reperfusion (I/R) continues to represent a significant cause of post-transplant liver failure. The roles that certain free radicals including nitric oxide (NO) and superoxide (O 2 –) play in this process are not well understood. The present study was designed to assess the role of endothelial cell nitric oxide synthase (eNOS) in I/R-induced liver injury in a murine model of hepatic I/R. Forty five minutes of partial (70%) hepatic ischemia followed by 3 and 6 h of reperfusion resulted in a significant increase in liver injury which occurred in the absence of neutrophil infiltration. eNOS-deficient mice displayed enhanced liver injury when compared to their wild type controls again in the absence of neutrophil infiltration. Interestingly, basal liver blood flow was significantly decreased in these mice when compared to controls though their blood flow during reperfusion was not significantly reduced from their wild type controls. Treatment of eNOS –/– mice with gadolinium chloride, a potent inhibitor of Kupffer cell function, but not superoxide dismutase, significantly reduced post-ischemic hepatocellular injury while either treatment protected the wild type mouse livers. Taken together, these data suggest that NO derived from eNOS may act to protect the post-ischemic liver possibly by suppression of Kupffer cell function and not by modulation of tissue perfusion. Further the data presented here would indicate that the protective effects conferred by SOD are related to its ability to increase the bioavailability of NO rather than by attenuating superoxide-dependent reactions. Data generated from these studies may prove useful in developing new drug therapies to treat the post-ischemic liver.

Role of NADPH oxidase-derived superoxide in reduced size liver ischemia and reperfusion injury

Hepatic resection with concomitant periods of ischemia and reperfusion (I/R) is required to perform reduced size liver transplantation such as split liver or liver donor transplantation. Although great progress has been made using these types of surgeries, there remains substantial risk to both donors and recipients, with a significant number of patients developing liver injury and failure. The objective of this study was to assess the roles of superoxide (O 2 −) and tumor necrosis factor-α (TNF-α) in the pathophysiology of a mouse model of reduced size liver combined with ischemia and reperfusion (RSL + I/R). We found that all male mice subjected to RSL + I/R died within 3–5 days following surgery. Mortality was always preceded by dramatic increases in liver injury and TNF-α expression in the absence of neutrophil infiltration. Using a long-lived, polycationic form of human manganese superoxide dismutase (pcMnSOD), NADPH oxidase-deficient mice (gp91 −/−) or a monoclonal antibody directed against mouse TNF-α, we demonstrated that hepatocellular injury (and mortality) were significantly attenuated. In addition, we found that pcMnSOD administration or NADPH deficiency reduced expression of TNF-α. Taken together, our data suggest that NADPH oxidase-derived O 2 − plays an important role in the pathophysiology of RSL + I/R-induced liver injury via its ability to enhance expression of TNF-α. We propose that therapies directed toward scavenging of O 2 −, inhibiting NADPH oxidase, and/or immuno-neutralizing TNF-α may prove useful in limiting the liver injury induced by surgical procedures that require resection and I/R such as split liver or living donor liver transplantation.

Antiphospholipid antibodies harness innate effectors, neutrophils and an alternative pathway of complement, to induce fetal damage

In a murine model of antiphospholipid antibody (aPL)-induced pregnancy loss, we have demonstrated that activation of complement, specifically C5a–C5a receptor interactions, leads to fetal loss and growth restriction. Yet, the effectors of tissue injury, the role of individual complement activation pathways and the precise targets for treatment remain unknown. Because C5a recruits and activates polymorphonuclear leukocytes (PMN) and because PMN infiltration is evident at sites of fetal resorption, we considered the possibility that PMN are critical cellular effectors of fetal damage. To assess the effects of aPL antibodies in mice depleted of granulocytes, we treated pregnant mice with anti-mouse Ly-6G (α-Gr) or control murine IgG2K prior to administration of human IgG containing aPL (aPL-IgG). In the absence of granulocytes, mice did not develop aPL-induced pregnancy complications. The frequency of fetal resorptions was similar to that of mice treated with IgG from healthy controls (NH-IgG), while treatment with control IgG2bK was not protective (% fetal resorption, aPL-IgG + α-Gr, 8.5 ± 1.5%; NH-IgG, 10 ± 2; aPL + IgG2bK, 39 ± 5%*; fetal weight (mg), aPL + α-Gr, 352 ± 48; NH-IgG, 370 ± 56; aPL + IgG2bK, 187 ± 28*; * aPL vs NH-IgG, P < 0.01). Immunohistochemical analysis of decidual tissues showed that, in the absence of neutrophil infiltration, either as a consequence of neutrophil depletion or due to blockade of the C5a–C5aR interaction, there was limited C3 deposition coincident with improved pregnancy outcomes. It has been suggested that neutrophils promote complement activation by secreting C3 and/or properdin at sites of inflammation, and thereby amplify complement activation via the alternative pathway. To examine the contribution of the alternative pathway to aPL-induced pregnancy loss, we performed studies in mice deficient in factor B (fB). In the absence of fB, mice were protected from aPL-induced fetal resorption and growth restriction (% fetal resorption fB-/- mice, aPL-IgG vs NH-IgG, 9.5 ± 2.4 vs 10.9 ± 2.1), indicating a role for the alternative pathway in fetal damage. This report, taken together with our previous work, shows that fB, C5 and C5aR are required for pregnancy complications triggered by aPL antibodies. Specifically, we identified the proinflammatory sequelae of C5a–C5aR interactions and the recruitment of neutrophils as the critical intermediates linking pathogenic aPL antibodies to fetal damage. Our findings identify the key innate immune effectors engaged by aPL antibodies that mediate poor pregnancy outcomes and provide novel and important targets for the prevention of pregnancy loss in antiphospholipid syndrome.

Regulation of postischemic liver injury following different durations of ischemia.

The objective of this study was to define the relationship among Kupffer cells, O(2)(-) production, and TNF-alpha expression in the pathophysiology of postischemic liver injury following short and long periods of ischemia. Using different forms of superoxide dismutase with varying circulating half-lives, a monoclonal antibody directed against mouse TNF-alpha, and NADPH oxidase-deficient mice, we found that 45 or 90 min of partial (70%) liver ischemia and 6 h of reperfusion (I/R) produced time-dependent increases in liver injury and TNF-alpha expression in the absence of neutrophil infiltration. Furthermore, we observed that hepatocellular injury induced by short periods of ischemia were not dependent on formation of TNF-alpha but were dependent on Kupffer cells and NADPH oxidase-independent production of O(2)(-). However, liver injury induced by extended periods of ischemia appeared to require the presence of Kupffer cells, NADPH oxidase-derived O(2)(-), and TNF-alpha expression. We conclude that the sources for O(2)(-) formation and the relative importance of TNF-alpha in the pathophysiology of I/R-induced hepatocellular injury differ depending on the duration of ischemia.

Role of nitric oxide in liver ischemia and reperfusion injury.

The present study was designed to assess the role of endothelial cell and inducible nitric oxide synthase (eNOS, iNOS)-derived NO in ischemia/reperfusion (I/R)-induced pro-inflammatory cytokine expression and tissue injury in a murine model of hepatic I/R. Forty-five min of partial hepatic ischemia and 3 h of reperfusion resulted in a significant increase in liver injury as assessed by serum alanine aminotransferase and histopathology which occurred in the absence of neutrophil infiltration. Both iNOS and eNOS deficient mice exhibited enhanced liver injury when compared to their wild type (wt) controls again in the absence of neutrophil infiltration. Interestingly, message expression for both tumor necrosis factor-alpha (TNF-alpha) and interleukin 12 (IL-12) were enhanced in eNOS, but not iNOS-deficient mice at 1 h post-ischemia when compared to their wt controls. In addition, eNOS message expression appeared to be up-regulated between 1 and 3 h ofreperfusion in wt mice while iNOS deficient mice exhibited substantial increases at I but not 3 h. Taken together, these data demonstrate the ability of eNOS and iNOS to protect the post-ischemic liver, however their mechanisms of action may be very different.

Upregulation of ICAM-1 and MCP-1 but not of MIP-2 and sensorimotor deficit in response to traumatic axonal injury in rats.

The pathophysiology of traumatic axonal injury (TAI) is only partially understood. In this study, we investigated the inflammatory response as well as the extent of neurological deficit in a rat model of traumatic brain injury (TBI). Forty-two adult rats were subjected to moderate impact-acceleration brain injury and their brains were analyzed immunohistochemically for ICAM-1 expression and neutrophil infiltration from 1 hr up to 14 days after trauma. In addition, the chemotactic factors MIP-2 and MCP-1 were measured in brain homogenates by ELISA. For evaluating the neurological deficit, three sensorimotor tests were applied for the first time in this model. In the first 24 hr after trauma, the number of ICAM-1 positive vessels increased up to 4-fold in cortical and subcortical regions compared with sham operated controls (P < 0.05). Maximal ICAM-1 expression (up to 8-fold increase) was detected after 4 days (P < 0.001 vs. 24 hr), returning to control levels in all brain regions by 7 days after trauma. MCP-1 was elevated between 4 hr and 16 hr post-injury as compared with controls. In contrast, neither neutrophil infiltration nor elevation of MIP-2, both events relevant in focal brain injury, could be detected. In all neurological tests, a significant deficit was observed in traumatized rats as compared with sham operated animals from Day 1 post-injury (grasping reflex of the hindpaws: P < 0.001, vibrissae-evoked forelimb placing: P = 0.002, lateral stepping: P = 0.037). In conclusion, after moderate impact acceleration brain injury ICAM-1 upregulation has been demonstrated in the absence of neutrophil infiltration and is paralleled by a selective induction of chemokines, pointing out that individual and distinct inflammatory events occur after diffuse vs. focal TBI.

Inflammation and oxygen free radical formation during pulmonary ischemia-reperfusion injury.

In a companion study, we showed that 2 h of warm unilateral lung ischemia followed by reperfusion resulted in bilateral tissue injury, indicated by increases in extravascular density (EVD) and permeability, measured as the pulmonary transcapillary escape rate (PTCER) for radiolabeled transferrin. EVD and PTCER measurements were obtained with the quantitative imaging technique of positron emission tomography (PET). In the current study, we evaluated this increase in EVD histologically and correlated EVD and PTCER with measurements of oxidant-reactive sulfhydryls (RSH) in plasma as a marker of oxygen free radical (OFR) formation. Histologically edema, leukocyte infiltration, and hemorrhage were all present on the ischemic side, but only after reperfusion, whereas only neutrophil infiltration was observed on the nonischemic side. Histology scores correlated with EVD (r = 0.81) and PTCER (r = 0.75), but permeability was abnormal at times even in the absence of neutrophil infiltration. Plasma RSH concentration from the ischemic lung decreased significantly (P less than 0.05) during pulmonary ischemia (i.e., before reperfusion) and returned to baseline on reperfusion. The degree of RSH oxidation did not correlate with the severity of injury as measured by PET or histology. Thus pulmonary ischemia-reperfusion injury is characterized by inflammation, hemorrhage, edema, and OFR formation. Injury occurred after reperfusion, not after ischemia alone. In addition, injury to the contralateral nonischemic lung suggests a neutrophil-independent circulating mediator of injury.