Mast Cell Counts Research Articles

Quantifying Mast Cell and Eosinophil Cellular Density in Skin Biopsy Tissue From Adults With Maculopapular Cutaneous Mastocytosis as Compared With Urticaria and Normal Skin: A Retrospective Histopathologic Study.

Maculopapular cutaneous mastocytosis (MPCM) is a rare disorder characterized by a pathologic accumulation of mast cells in the skin, which may or may not be accompanied by systemic mastocytosis. Diagnosis of MPCM on skin biopsy can be challenging because the findings may be subtle. Although mast cell density in MPCM has been reported, data informing a proposed cutoff for diagnosis and diagnostic criteria are limited. We identified adult patients diagnosed with MPCM and urticarial tissue reaction/chronic urticaria on skin biopsy and compared the mast cell and eosinophil counts per 1 mm2 in 10 cases each of MPCM, chronic urticaria, and normal skin from routine biopsies. All slides were stained with CD117, and CD117-positive mast cells were counted per 1 mm2 using digital microscopy. Eosinophils were counted on hematoxylin and eosin-stained slides per 1 mm2 using digital microscopy. The median number of mast cells per 1 mm2 was significantly higher in MPCM than in cases of urticaria and normal skin/control tissue (177.3 vs. 26.8 vs. 47.8 mast cell per mm2, respectively; P ≤ 0.001). The calculated "cut point" for mastocytosis versus chronic urticaria and normal skin was 66 mast cells per 1 mm2, whereas the value for controls versus urticaria was 37 mast cells per 1 mm2. Eosinophils had similar density in MPCM and urticaria, and their presence was significant in the differentiation of MPCM and urticaria from normal tissue. This study adds to the literature by providing objective mast cell density data to distinguish challenging cases of cutaneous mastocytosis from urticarial reactions and normal skin. Future studies could explore the development of computer-aided estimations of cellular density with more extensive comparison with other inflammatory conditions to translate our findings more readily into clinical practice.

Correlation of intratumoral mast cell quantity with psychosocial distress in patients with pancreatic cancer: the PancStress study

Mast cells are commonly found in pancreatic ductal adenocarcinoma (PDAC), yet their role in the disease remains uncertain. Although mast cells have been associated with depression in several diseases, their connection to PDAC in this context remains unclear. This study explored the correlation between mast cells and psychosocial stress in patients with PDAC. Prior to surgery, 40 patients with PDAC (n = 29 primary resected, n = 11 neoadjuvant treated) completed four questionnaires assessing stress and quality of life. Immunostaining was performed on the resected tumor tissue. Spearman analysis was employed to correlate mast cells with distress and neuropeptides serotonin and beta-endorphin serum and tissue levels. Patients with PDAC exhibited elevated levels of distress and worry. Lower number of mast cells within the tumor correlated with greater psychological burden. Among primary resected patients, mast cell count moderately correlated with joy and inversely with worries. Following neoadjuvant chemotherapy, strong inverse correlation was observed between anxiety, depression, and mast cell quantity. No correlation was found between mast cells and serotonin or beta-endorphin levels. In summary, mast cell presence inversely correlates with psychosocial stress, suggesting a link between immune cells and psychological well-being in pancreatic cancer. Targeting mast cells might offer therapeutic avenues for addressing cancer-induced depression and anxiety.

GPR55 antagonist CID16020046 suppresses DNCB-induced atopic dermatitis-like symptoms by suppressing Th1/Th2/Th17 populations in mice.

G protein-coupled receptor 55 (GPR55) is a lipid-sensing receptor that plays a role as an immune mediator and is primarily upregulated during immune cell activation. There is a lack of knowledge about the role of GPR55 in allergic inflammatory diseases such as atopic dermatitis. The purpose of this study was to investigate the role of GPR55 through the use of its antagonist, CID16020046, in an atopic dermatitis mouse model. It was found that BALB/c mice develop lesions similar to those associated with atopic dermatitis following sensitization and repeated exposure to 1-chloro-2,4-dinitrobenzene (DNCB). It was found that CID16020046 (1 mg/kg, i.p.) alleviated the atopic dermatitis-like symptoms as well as immune dysregulation caused by DNCB. Based on histopathological analysis, CID16020046 reduced ear thickening and mast cell counts in the dermis. CID16020046 decreased DNCB-induced increases in serum IgE levels, as measured using enzyme-linked immunosorbent assays. A significant reduction in lymph node hypertrophy was also observed with CID16020046 as well as significant reductions in CD4+ T helper 1 (Th1), Th2, and Th17 cells in the lymph nodes. As a result of the administration of CID16020046, cytokines of Th1 (IFN-γ), Th2 (IL-4 and IL-13), and Th17 (IL-17A) types were also reduced in the skin and lymph nodes. In conclusion, blocking GPR55 alleviates DNCB-induced atopic dermatitis-like symptoms, suggesting that GPR55 is a potential therapeutic target for allergic inflammatory diseases via immunoregulation.

Topiramate Inhibits Capsaicin-Induced Mast Cell Degranulation and CGRP Release in Rat Dura Mater

Background/Objectives: Migraine is a disease that stands out for its high prevalence and socioeconomic costs. It involves the entire trigeminovascular system, the signaling substances, and their targets. However, the role of meningeal mast cells in migraine is still unclear. To better understand one of the components of neurogenic inflammation underlying migraine pathophysiology, we developed an in vivo rat model in which the dura mater was exposed bilaterally to investigate the influence of topiramate on capsaicin-induced mast cell degranulation and CGRP release from dura mater. Methods: On the day of the experiment, rats were anesthetized, and a craniectomy was performed on each parietal bone. Test substances were applied in situ over the dura mater using the right and left sides of the dura mater for the test and control, respectively. After exposure, the dura mater was processed for mast cell staining and counting. Using this setup, the effect of capsaicin (10−3 M) was evaluated in rats of both sexes, and subsequently the effect of in situ (10−3 M, 20 µL) and (20 mg/kg/day for 10 days) topiramate treatment on mast cell degranulation and CGRP release were evaluated. Results: In both female and male rats, there was a greater amount of degranulated mast cells in the side stimulated by capsaicin compared to the control side in both females (18 ± 3% vs. 74 ± 3%; p = 0.016) and males (28 ± 2% vs. 74 ± 3%, p = 0.016). In the group treated with topiramate for 10 days prior to the experiments, capsaicin did not induce mast cell degranulation (control 20 ± 1% vs. capsaicin 22 ± 1%, p = 0.375) in contrast to animals treated for 10 days with gavage control (control 25 ± 1% vs. capsaicin 76 ± 1%, p = 0.016). Topiramate applied in situ concomitant with capsaicin did not protect the mast cells from degranulation in response to capsaicin (38 ± 2% vs. 44 ± 1%, p = 0.016). There was a significant reduction in CGRP release from the dura mater in the group treated with topiramate for 10 days compared to the control. Conclusions: This study demonstrates a novel experimental model wherein systemic administration of topiramate is observed to modulate the impact of capsaicin on meningeal mast cell degranulation.

Efficacy and Potential Mechanisms of Naringin in Atopic Dermatitis

Atopic dermatitis (AD) is one of the most prevalent chronic inflammatory skin diseases. Topical treatments are recommended for all patients regardless of severity, making it essential to develop an effective topical AD treatment with minimal side effects; We investigated the efficacy of topical application of naringin in AD and explored the possible mechanisms using an AD mouse model induced by 1-chloro-2,4-dinitrobenzene (DNCB). Clinical, histological, and immunological changes related to AD and Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling proteins in the skin tissues were measured as outcomes; Naringin treatment resulted in a significant improvement in dermatitis severity score and reduced epidermal thickness and mast cell count in the skin (p < 0.05). Naringin also demonstrated the ability to inhibit DNCB-induced changes in interleukin (IL) 4, chemokine (C-C motif) ligand (CCL) 17, CCL22, IL1β, interferon-gamma (IFN-γ), and tumor necrosis factor-alpha (TNF-α) levels by quantitative real-time polymerase chain reaction (qRT-PCR) and IL13 by enzyme-linked immunosorbent assay (ELISA) (p < 0.05). Western blot results exhibited the decreased JAK1, JAK2, STAT1, STAT3, phospho-STAT3, and STAT6 expression in the naringin-treated groups (p < 0.05); The findings of this study suggest that topical naringin may effectively improve the symptoms of AD and could be used as a therapeutic agent for AD.

Clinical variability of equine asthma phenotypes and analysis of diagnostic steps in phenotype differentiation

BackgroundEquine asthma is a common, non-infectious, chronic lung disease that affects up to 80% of the horse population. Strict phenotyping and identification of subclinically asthmatic horses can be challenging. The aim of this study was to describe equine asthma phenotypes (mild, moderate, and severe asthma) defined by BALF cytology and occurrence of clinical signs in a population of privately owned horses and to identify the variables and examination steps with best discriminative potential. The standardised examination protocol included clinical examinations, blood work, airway endoscopy with bronchoalveolar lavage fluid analysis, arterial blood gas analysis and radiography under clinical conditions performed by one veterinarian.ResultsOut of 26 horses, four were diagnosed with mild (subclinical), seven with moderate, and seven with severe asthma based on clinical examination and BALF cytology. Eight horses served as controls. Cough with history of coughing was the strongest variable in phenotype differentiation. Factor analysis revealed an increasing clinical variability with disease severity and an overlapping of clinical presentations between phenotypes. Elevated mast cell (4/4 horses) and neutrophil counts (3/4 horses) in bronchoalveolar lavage cytology differentiated mild asthmatic horses from healthy horses. Moderate and severe asthmatic horses were characterised by clinical signs and neutrophil counts.ConclusionsThe results indicate that medical history, clinical examination and bronchoalveolar lavage cytology are minimum indispensable steps to diagnose equine asthma and that phenotypes are clinically overlapping. A differentiation of three phenotypes without neutrophil and mast cell counts in bronchoalveolar lavage cytology is not sufficient for clinical diagnostics. A comparably exact diagnosis cannot be achieved by relying on alternative examinations used in this study. Screenings of inconspicuous horses with bronchoalveolar lavage can aid in diagnosing subclinically affected animals, however, group size was small, the procedure is invasive and clinical relevance of slightly elevated cells in bronchoalveolar lavage remains unclear. Clinical relevance could not be clarified in this study, since follow-up examinations or lung function testing were not performed.

Tranilast Treatment Prevents Chronic Radiation-Induced Colitis in Rats by Inhibiting Mast Cell Infiltration

Introduction: Mast cells are the principal cells involved in acute and chronic colitis due to radiation, known as radiation-induced colitis (RIC). In this study, we investigated whether pretreatment with tranilast, a mast cell inhibitor, could alleviate chronic RIC. Methods: A total of 23 Sprague-Dawley rats were randomly divided into three groups: control group (n = 5), radiation group (RG, n = 9), and tranilast-pretreated radiation group (TG, n = 9). The rats in the RG and the TG were irradiated in the pelvic area (1.5 cm from the anus) with a single dose of 20 Gy under general anesthesia. Tranilast (100 mg/kg) was administered intraperitoneally to the rats of the TG for 10 days, starting from the day of pelvic radiation. Ten weeks after radiation, the rats were euthanized. Rectal tissue samples were histologically evaluated for the total inflammation score (TIS) and mast cell count. The expression of MUC2, MUC5AC, and matrix metalloproteinase-9 (MMP-9) was also assessed immunohistochemically. Results: Both the TIS and specific components of TIS such as epithelial atypia, vascular sclerosis, and colitis cystica profunda (CCP) were significantly higher in the RG than in the TG (p = 0.02, 0.038, 0.025, and 0.01, respectively). Thein number of infiltrating mast cells was significantly higher in the RG than in the TG (median [range]: 20 [3−54] versus 6 [3−25], respectively; p = 0.034). Quantitatively, the number of MMP-9-positive cells was significantly higher in the RG (23.67 ± 19.00) than in the TG (10.25 ± 8.45) (mean ± standard deviation; p < 0.05). TIS and MMP-9 exhibited a strong association (correlation coefficient r = 0.56, p < 0.05). Immunohistochemically, the mucin-lake of CCP showed no staining for MUC5AC but was stained positive for MUC2. Conclusion: Tranilast pretreatment of chronic RIC showed an anti-inflammatory effect associated with the reduction of mast cell infiltration and MMP-9 expression.

Interactions between eosinophils and IL-5Rα–positive mast cells in nonadvanced systemic mastocytosis

Bidirectional interactions between eosinophils and mast cells (MCs) have been reported in various allergic diseases. Bone marrow (BM) eosinophilia, and to a lesser extent blood eosinophilia, is common in systemic mastocytosis (SM), but its significance remains unknown. To describe blood and BM eosinophil characteristics in SM. A large collection of BM biopsies was analyzed using immunohistochemical staining and whole-slide imaging. Eosinophil and extracellular granules were detected by eosinophil peroxidase (EPX) staining, and MCs by KIT staining. Complementary analyses were conducted using flow cytometry and immunofluorescence. Eosinophil infiltrates and large areas of eosinophil degranulation were observed within or around BM MC infiltrates in SM. EPX staining surface, highlighting intact eosinophils and eosinophil degranulation, was higher in non-advanced-SM (n=37 BM biopsies) compared to both controls (n=8, p=0.0003) and to advanced SM (n=24, p=0.014). In non-advanced SM, positive correlations were observed between serum tryptase levels and percentages of eosinophil counts in BM aspirations (Spearman r coefficient r=0.38, p=0.038), eosinophils count in BM biopsies (r=0.45, p=0.007), EPX staining (r=0.37, p=0.035) and eosinophil degranulation (r=0.39, p=0.023). Eosinophil counts in BM biopsies also correlated with MC counts (r=0.47, p=0.006) and KIT staining surface (r=0.49, p=0.003). BM MCs expressed interleukin-5 receptor and other usual eosinophil cytokine/chemokine receptors, and blood eosinophils display several increased surface markers compared to controls, suggesting an activated state. Our data suggest a possible crosstalk between MCs and eosinophils, supporting MC tryptase release and MC activation-related symptoms. This suggests a rationale for targeting eosinophils in non-advanced-SM not fully controlled by other therapies.

Immunohistochemical Analysis of CD117 in the Mast Cells of Odontogenic Keratocysts.

Odontogenic lesions contain mast cells (MCs), particularly those with a cystic appearance. Because of their high recurrence rates and aggressive clinical behaviour, odontogenic keratocysts (OKCs) require special treatment. A particular kind of protein called cluster of differentiation (CD) 117/ receptor tyrosine kinase (c-KIT) is present on the surface of many cells. Most hematopoietic cells lose their expression of KIT during the differentiation process, with the exception of MCs, which continue to express KIT throughout their lifetime. Using the CD117 immunomarker, this immunohistochemical investigation sought to assess the presence and location of MCs in OKCs and examine the relationship between MC numbers in sporadic, syndromic, and recurrent OKCs. The study comprised 30 paraffin-embedded tissue specimens, and a histopathological diagnosis was made from hematoxylin and eosin-stained sections with a thickness of 4-5 µ. Out of 30 specimens, 21 were sporadic, six were recurrent OKCs, and three were syndrome-associated OKCs. CD-117/c-kit rabbit polyclonal primary antibody was used to stain the sections for observing MCs, which were then viewed under a light microscope with a digital camera and a desktop computer with MICAPS software for viewing images. To compare the number of MCs among OKCs, a one-way ANOVA test was used. Our study revealed that a statistically significant increase in MCs has been observed in the subepithelial and deep connective tissue of recurrent OKC (p < 0.05). However, a comparison of the mean MC value among three OKC subtypes did not reveal any statistically significant differences. An increased mast count was observed in the deep connective tissue layer of syndromic OKC under multiple comparisons. Our study concluded that MCs were present in increased numbers both in the superficial and deep connective tissue of recurrent OKCs, indicative of their aggressive clinical behaviour. Increased mean MC counts observed in some of the sporadic cases may be an indicator of their chances of recurrence in the future.

Enumeration of mast cells in the human umbilical cord: implications for coiling patterns

The abnormal umbilical cord coiling pattern affects the well-being of the newborn in different ways. Moreover the differentiation of mast cell according to these patterns may also varies. The objective: to investigate the detection and enumeration of mast cells in different patterns in human coiling cords in order to explore their effect on the newborn baby health.Materials and methods. Umbilical cord samples were collected from 105 healthy pregnant women. The cords were collected immediately after labor and kept in formalin (10%), according to coil type. Three major categories of umbilical cord coiling (normocoiled, hypercoiled, and hypocoiled) were determined according to the Umbilical Cord Index (UCI).The histological sections of the umbilical cord were collected according to UCI. This step is followed by using different histological stains, including hematoxylin and eosin and toluidine blue stains. The expression of the CD117 mast cell population in the umbilical cord tissue was determined using the immunohistochemical method in the subamniotic, perivascular and central areas. The enumeration of mast cells was done by direct counting and using Image J software. Results. The comparison of mast cell counts using Image J showed statistically significant variations (P&lt;0.05) between normocoiled and hypercoiled cords in mast cell populations. No significant changes (P&gt;0.05) were found in mast cell counts between normocoiled and hypocoiled umbilical cords. Conclusions. The mast cell distribution interpretation suggested that mechanical coiling during embryonic growth affects mast cell dispersal in sectioned umbilical cords. This interpretation’s functional relevance should be applied to coiling events that do not have harmful outcomes on the fetus. Future research could be done on the distribution of mast cells in the abnormally coiled umbilical cords associated with negative perinatal outcomes.

The prognostic significance of CD117-positive mast cells and microvessel density in colorectal cancer.

The prognostic significance of angiogenesis has been demonstrated in various types of cancer. However, in colorectal cancer (CRC), there are conflicting results regarding the relationship between angiogenesis and clinical-histopathological prognostic factors. Mast cells are immune system cells found in the inflammatory microenvironment; their role in carcinogenesis and prognosis remains unclear although they are considered to cause cancer development and progression. The present study aims to evaluate the prognostic significance of mast cell accumulation and angiogenesis assessed by microvessel density (MVD) in patients with CRC. Patients who underwent curative resection and who were not treated with neoadjuvant chemotherapy were included. The anti-CD34 antibody and anti-CD117 antibody were utilized for the immunohistochemical assessment of MVD and the mast cell count (MCC) in the tissue samples, respectively. The relationship between MCC, MVD, survival and clinical-histopathological prognostic factors were evaluated. A total of 94 patients were enrolled to the study. In a median 49-month follow-up, 65 patients (69.1%) died. The 5-year disease-free survival was 61.1% and 31.3% for the group with CD34 < 18.3% and CD34 > 18.3%, respectively (P = .001). The same groups presented 5-year overall survival rates of 77, 1% and 51, 4%, respectively (P, .012). The MVD was found to be associated with the pathological T stage, lymph node metastasis and distant metastasis (P < .05). Although the MCC was positively correlated with MVD, there was no association between the MCC and clinical-histopathological prognostic factors. MVD-assessed angiogenesis was significantly related to survival and the clinical-histopathological prognostic factors in patients diagnosed with CRC.

Divergent histopathological and molecular patterns in chemically induced interstitial cystitis/bladder pain syndrome rat models

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a complex chronic pain disorder with an elusive etiology and nonspecific symptoms. Although numerous animal models with phenotypes similar to human disease have been established, no available regimen can consistently alleviate clinical symptoms. This dilemma led us to question whether current animal models adequately represent IC/BPS. We compared four commonly used IC/BPS rat models to determine their diverse histopathological and molecular patterns. Female rats were given single treatments with hydrochloric acid (HCL), acetic acid (AA), protamine sulfate plus lipopolysaccharide (PS + LPS), or cyclophosphamide (CYP) to induce IC/BPS. Bladder sections were stained for histopathologic evaluation, and mRNA expression profiles were examined using next-generation sequencing and gene set analyses. Mast cell counts were significantly higher in the HCL and AA groups than in the PS + LPS, CYP, and control groups, but only the AA group showed significant collagen accumulation. The models differed substantially in terms of their gene ontology and Kyoto encyclopedia of genes and genomes pathways. Our observations suggest that none of these rat models fully reflects the complexity of IC/BPS. We recommend that future studies apply and compare multiple models simultaneously to fully replicate the complicated features of IC/BPS.

Hydrogel-Based Treatment of House Dust Mite-Induced Atopic Dermatitis through Triple Cleaning of Mites, Bacteria, and ROS-Related Inflammation.

Atopic dermatitis (AD) is a chronic and recurrent inflammatory disease caused by abnormalities in skin immunoregulation. House dust mite can directly damage the skin barrier and thus sensitize the skin, which is one of the main allergens inducing AD in humans and widely exists in daily life. Meanwhile, the accompanying bacterial infections and exposure to additional allergens exacerbate the condition by generating excessive reactive oxygen species (ROS). Herein, we have developed the CPDP hydrogel with injectable and self-healing ability to combat pathogenic microorganisms and inflammatory environments for AD therapy. In vitro experiments have affirmed the efficacy of the CPDP hydrogel in combating mites, killing bacteria, and scavenging ROS. In a mouse model closely mimicking HDM-induced AD, the CPDP hydrogel has shown superior therapeutic effects, including reducing epidermal thickness and mast cell count, increasing collagen deposition, as well as down-regulating pro-inflammatory factors.

Can Electrical Stimulation Prevent Recurrence of Keloid Scars? A Scoping Review.

Objective: Keloids represent a symptomatic, aberrant healing process that is difficult to treat with high recurrence rates spanning from 55% to 100% if treated via excision without adjuvant therapy. Electrical stimulation (ES) has demonstrated findings that suggest it could reduce the recurrence rate of keloids after resection. Therefore, the aim of this study is to conduct a scoping review to investigate ES as an adjuvant therapy for decreasing keloid recurrence after excision. Approach: A scoping review was performed using PubMed and Web of Science databases. The search strategy encompassed terms linking keloids and various aspects of electrical stimulation. Results: Our search yielded 2,229 articles, of which 115 articles were analyzed as full text and 1 article met inclusion criteria. Despite this, ES has demonstrated other evidence that suggests its utility. ES has been shown to counter keloidic features by reducing mast cell counts, shifting wound composition from M2 to M1 macrophages, promoting angiogenesis, and controlling fibroblast orientation and location. An alternating current will orient fibroblasts perpendicular to the current without unintended migration. Innovation: Our study indicates that, based on a compilation of clinical and preclinical in vitro data, the optimal scenario for ES in the role of keloid treatment is after excision with a biphasic pulsed application and square waveform. Conclusions: ES could serve as a multifaceted, adjuvant treatment after keloid excision, steering the healing process away from keloid-associated characteristics. Its cost-effectiveness means it could be adopted globally, providing a strategy to mitigate the burden of keloids irrespective of other available treatments or economic conditions.

(004) ROUTINE PATHOLOGY EXAMINATION OF EXCISED SPECIMEN FROM PATIENTS WITH NEUROPROLIFERATIVE VESTIBULODYNIA

Abstract Introduction Neuroproliferative vestibulodynia (NPV) is suspected in individuals with vulvas with complaints of entrance dyspareunia, vestibular allodynia and hyperalgesia, after ruling out other causes. When conservative biopsychosocial treatments for suspected NPV are unsuccessful, vestibulectomy may be an appropriate option. Excised vestibular surgical specimens are routinely sent for pathologic assessment including hematoxylin and eosin (H&amp;E) staining. Objective To review reports of gross and microscopic pathology examinations of excised vestibular specimens from a cohort of patients with NPV and compare immunohistochemical staining density among subgroups classified by severity of subepithelial inflammatory infiltrate. Methods Excised specimens from vestibulectomy surgeries were placed in 10% neutral buffered formalin prior to pathology examination. Routine pathology assessment included gross examination and cytological characterization of H&amp;E-stained vestibular tissue for malignancy, viral nuclear changes (in addition to P16 staining as needed), and quality of the vestibular epithelium and subepithelial inflammatory infiltrate. Severity of this infiltrate was classified by the pathologist as mild, mild-moderate, moderate, or severe. Additional vestibular tissue sections were processed for immunohistochemical staining for CD117 and PGP9.5, protein markers consistent with mast cells and nerves, respectively. Separating the tissues into subgroups based on severity of subepithelial inflammatory infiltrate, they were compared to mast cell counts and immunopositive mean fractional area for CD117 and PGP9.5 using the Kruskal-Wallis test. Results Gross examinations of the 1:00-11:00 (n = 63) and 12:00 (n = 54) regions of vestibular tissue showed mean dimensions (length, width, thickness) to be 5.8 x 2.1 x 0.6 cm and 1.0 x 0.7 x 0.3 cm, respectively. Microscopic examinations revealed no malignant cells in any specimen, and viral nuclear findings were consistent with HPV in 3 specimens. Vestibular tissue was characterized as non-reactive squamous epithelium in 91% and 93% of specimens for the 1:00-11:00 and 12:00 regions, respectively. Mature lymphocytes were found in the subepithelial stromal infiltrate of 67% of specimens in both the 1:00-11:00 and 12:00 regions. Severity of subepithelial stromal infiltrate was reported as: mild in 67% and 65%; mild-moderate in 5% and 4%; moderate in 14% and 15%; and severe in 14% and 17% of cases for the 1:00-11:00 and 12:00 regions, respectively. Among the subgroups categorized by severity of inflammatory infiltrate, there were no significant differences for CD117-immunopositive cell counts or mean fractional area of CD117 and PGP9.5 in the 1:00-11:00 and 12:00 regions. Conclusions Routine pathology examination including H&amp;E staining is standard for vestibulectomy specimens. There were no significant differences found among subgroups comparing severity of subepithelial inflammatory infiltrate with immunohistochemical data. Thus, information gleaned from routine pathology examination did not provide confirmation of the diagnosis of NPV. To better understand NPV, excised vestibular tissue should also be immunostained for CD117 and PGP9.5. Disclosure No.

The immune landscape of uterine fibroids as determined by mass cytometry

ObjectiveTo study the differences in immune cell profile in uterine fibroids (Fib) and matched myometrium (Myo). DesignObservational Study SettingLaboratory Study PatientsThe study included tissue that was collected from ten pairs of fibroid and matched myometrium from women, not on hormonal medications, undergoing hysterectomy and myomectomy. InterventionsNone Main Outcome MeasuresDifferences in immune cell and cytokine composition between fibroid and matched myometrium Result(s)The mass cytometry analysis indicated that fibroids had a significantly higher number of NK cells, total macrophages, M2 macrophages, and conventional dendritic cells when compared to matched myometrium from the same patient. In contrast, fibroids had significantly fewer CD3 and CD4 T cells when compared to myometrium. The mass cytometry analysis did not show any significant difference in the number of resting mast cells. IFC and IHC imaging confirmed the CytoF results, showing a significantly higher (p<0.05) number of NK, tryptase-positive mast cells indicative of mast cell activation, total macrophage, and M2 cells in Fibroids and a significantly lower (p<0.05) number of CD3 and CD4 T cells. The cytokine assay revealed significantly increased (p<0.05) levels of IFNA2, Il-1α, and PDGF-AA and significantly lower levels of M-CSF and IL-1RA in Fib. ConclusionOur results show significant differences in immune cell populations and cytokine levels between Fib and Myo. There was a significant increase in total number of macrophages, M2 macrophages, NK cells, and dendritic cells and a significant decrease in CD3 and CD4 T cells in Fib. IHC confirmed no differences in total resting mast cell count, but a significant increase in tryptase-positive mast cells in Fib. Fibs also expressed significantly higher levels of IFNA2, IL-1α, and PDGF-AA and significantly lower levels of IL-1RA and M-CSF as compared with matched myometrium. These findings provide a foundation for further studies exploring the role of immune cells in Fib development.

Bilateral bronchoalveolar lavage cytology profiles in a warmblood horse population during a 1-year period.

Bronchoalveolar lavage (BAL) cytology results from 1 lung might not be representative of both lungs. To determine whether the lung site sampled would influence the horse's BAL cytology profile, and if a pooled BAL sample would be superior with regard to BAL cytology diagnosis in a cohort of healthy and subclinical asthmatic warmblood horses. Fifty-nine horses in 2021 and 70 horses in 2022, the follow-up included 53 of the same in each year. A cross-sectional study with follow-up included BAL cytology samples from individual lungs and from pooled BAL samples. The BAL samples were enumerated and differential cell count were applied to categorize the horses as control or with airway inflammation (AI). Bronchoalveolar lavage mast cell count was higher in left lung compared to right lung (2021; median 1.6 [range, 0.6-3.3] vs 1.2 [0.7-1.5] P = .009, 2022; median 3.1 [2.1-4.2] vs 2.4 [1.7-3.4], P < .001) and compared to pooled samples (2022; median 2.6 [1.7-3.7], P < .001). Between year 2021 and 2022, 17 of the horses had changes in BAL cytology from control to AI or vice versa. Pooled BAL sample was the least reliable for detecting AI, and was not representative of the overall lung condition.

Chang-Kang-Fang alleviates diarrhea predominant irritable bowel syndrome (IBS-D) through inhibiting TLR4/NF-κB/NLRP3 pathway

Ethnopharmacological relevanceChang-Kang-Fang (CKF), originated from traditional Chinese medicine (TCM) formulas, has been utilized to treat diarrhea predominant irritable bowel syndrome (IBS-D) based on clinical experience. However, the underlying mechanism of CKF for treating IBS-D remains unclear and need further clarification. Aim of the studyThe objective of this present investigation was to validate the efficacy of CKF on IBS-D model rats and to uncover its potential mechanism for the treatment of IBS-D. Materials and methodsWe first established the IBS-D rat model through neonatal maternal separation (NMS) in combination with restraint stress (RS) and the administration of senna decoction via gavage. To confirm the therapeutic effect of CKF on treating IBS-D, abdominal withdrawal reflex (AWR) scores, the quantity of fecal pellets, and the fecal water content (FWC) were measured to evaluate the influence of CKF on visceral hypersensitivity and the severity of diarrhea symptom after the intragastric administration of CKF for 14 days. Subsequently, enzyme linked immunosorbent assay (ELISA) was applied to assess the effect of CKF on neuropeptides substance P (SP) and 5-hydroxytryptamine (5-HT), as well as inflammatory cytokines in serum and in intestinal tissues. Further, colonic pathological changes, the amount of colonic mast cells, and the expression level of occludin in rat colon tissues, were investigated by hematoxylin-eosin (HE) staining, toluidine blue staining, and immunohistochemistry, respectively. To explore the underlying mechanisms, alterations in colonic RNA transcriptomics for the normal, model, and CKF treatment groups were assessed using RNA sequencing (RNA-Seq). Subsequently, quantitative real-time polymerase chain reaction (qRT-PCR), Western blot (WB), and immunofluorescence (IF) assays were applied to validate the effect of CKF on predicted pathways in vivo and in vitro. In addition, to elucidate the potential active compounds in CKF, 11 representative components found in CKF were selected, and their anti-inflammation potentials were evaluated using LPS-treated RAW264.7 cell models. ResultsCKF treatment significantly reduced the number of fecal pellets, attenuated visceral hypersensitivity, and decreased 5-HT and SP concentrations in serum and colon tissues, along with a reduction in colonic mast cell counts, correlating with improved symptoms in IBS-D rats. Meanwhile, CKF treatment reduced the colonic inflammatory cell infiltration, lowered the levels of IL-6, TNF-α, and IL-1β in serum and colon tissues, and increased the occludin protein expression in colon tissues to improve inflammatory response and colonic barrier function. RNA-Seq, in conjugation with our previous network pharmacology analysis, indicated that CKF might mitigate the symptoms of IBS-D rats by inhibiting the Toll like receptor 4/Nuclear factor kappa-B/NLR family pyrin domain-containing protein 3 (TLR4/NF-κB/NLRP3) pathway, which was confirmed by WB, IF, and qRT-PCR experiments in vivo and in vitro. Furthermore, coptisine, berberine, hyperoside, epicatechin, and gallic acid present in CKF emerged as potential active components for treating IBS-D, as they demonstrated in vitro anti-inflammatory effects. ConclusionOur findings demonstrate that CKF effectively improves the symptoms of IBS-D rats, potentially through the inhibition of the TLR4/NF-κB/NLRP3 pathway. Moreover, this study unveils the potential bioactive components in CKF that could be applied in the treatment of IBS-D.

Effect of Mixed Probiotics on Ovalbumin-Induced Atopic Dermatitis in Juvenile Mice.

Atopic dermatitis is one of the most common dermatologic problems, especially in children. Given the ability of symbiotic microorganisms in modulating the immune system, probiotics administration has been studied in previous research in the management of atopic dermatitis. However, there are conflicting results between studies. In this study, we aimed to assess the effectiveness of mixed probiotics as a treatment option for atopic dermatitis induced by ovalbumin. BALB/c juvenile mice were classified and divided into the ovalbumin group, mixed probiotic group (ovalbumin + LK), and control group. Except for the control group, all mice were sensitized with ovalbumin to establish a model of atopic dermatitis. The mixed probiotics were given by gavage for 14 days. Mice body weight, skin lesions, skin inflammation, ovalbumin-specific Ig, the number of Treg and CD103+DC, and the expression level of PD-1/PD-L1 were examined. The results showed that mixed probiotics can improve body weight and alleviate skin symptoms. Mixed probiotics reduced serum Th2 inflammatory factors, eosinophils, mast cell degranulation, mast cell count, and the expression of ovalbumin-specific immunoglobulin E/G1 and increased the anti-inflammatory cytokine interleukin-10, Treg cells, CD103+DC cells, and the expression level of PD-1/PD-L1. These findings suggest that mixed probiotics could be a viable treatment option for atopic dermatitis and provide insight into the underlying mechanisms involved.

Abstract 6673: Tumor microbial burden is regulated by mast cells and determines immunotherapy responses

Abstract Immune checkpoint inhibitors (ICI) have notably improved overall survival rates across various cancers, particularly in cases of mismatch repair deficient cancer (MMRd). However, numerous factors influence patient response following ICI treatment. Beyond genetic factors, mutations, and levels of immune cell infiltration, several studies highlight the correlation between the gut microbiome and treatment response rates. Furthermore, specific bacterial compositions have been observed to shift during therapeutic interventions. Notably, studies have demonstrated that patients who used antibiotics before and during ICI treatment exhibited lower progression-free survival and overall survival, serving as evidence for this association. Our previous investigations elucidated the impact of distinct tumor microbial burdens on modulating immune activation. Consequently, our hypothesis posits the substantive involvement of the interplay between tumor microbial burden and the immune system response to ICI treatment. We evaluated the presence of intra-tumoral microbes within Colorectal cancers (CRC) by examining TCGA data. Patients with elevated microbial levels demonstrated heightened immune activity and better survival rates. Using cybersport analysis, we validated increased mast cell infiltration in CRC patients with abundant microbes. Quantification involved assessing bacterial burden through 16s rRNA via FISH staining and mast cell counts using tryptase via IHC staining. Reducing bacterial load in MC38 cancer model, achieved by locally administering antibiotics, led to a diminished immune response when PD-1 was introduced to these mice. Cross-referencing TCGA data, we identified upregulated genes in CRC patients with high microbial burden and downregulated genes in mice receiving local antibiotics after MC38 cell implantation. The common genes were associated with immune responses, suggesting a strong correlation between bacterial burden and immune activity in CRCs. In conclusion, the high burden of bacteria in CRC improves immune response to ICI and increases the infiltration of mast cells, which all contribute to better survival rates. Citation Format: Hajar Rajaei, Jeong-Hoon Jang, Haoyue Liu, Erika Y. Faraoni, Olivia Le Roux, Vidhi Chandra, Virginia Tahan, Le Li, Erick Riquelme, James Robert White, Luis A. Diaz Jr., Florencia McAllister. Tumor microbial burden is regulated by mast cells and determines immunotherapy responses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6673.