Tryptase-positive Mast Cells Research Articles

Tu1795 Increased Number of Tryptase-Positive Mast Cells in the Colonic Mucosa of IBS Patients in Mexico and Its Relation With Perceived Stress

Tu1795 Increased Number of Tryptase-Positive Mast Cells in the Colonic Mucosa of IBS Patients in Mexico and Its Relation With Perceived Stress

Non-random spatial relationships between mast cells and microvessels in human endometrial carcinoma.

Mast cells (MCs) accumulate in the stroma surrounding tumors, where they secrete angiogenic cytokines and proteases, and an increased number of MCs have been demonstrated in angiogenesis associated with solid and hematological tumors. The aim of this study is to contribute to the knowledge of distribution of MCs in tumors, investigating the pattern of distribution of tryptase-positive MCs around the blood vessels in human endometrial carcinoma samples by introducing a quantitative approach to characterize their spatial distribution. The results have shown that in human endometrial cancer bioptic specimens the spatial distribution of MCs shows significant deviation from randomness as compared with control group in which, instead, the spatial distribution of MCs is consistent with a random distribution. These findings confirm that MCs enhance tumor angiogenesis and their preferential localization along blood vessels and sites of new vessel formation sustaining the suggestion for an association between MCs and angiogenesis. However, this spatial association between vessels and MCs might simply reflect migrating MCs from the blood stream at vessel growing sites.

The role of aldo-keto reductase 1C3 (AKR1C3)-mediated prostaglandin D2 (PGD2) metabolism in keloids.

Keloids are progressively expanding scars, mostly prevalent in individuals of African descent. Previous data identified increased mast cell number and activation state in keloids suggesting a role in disease progression. The major eicosanoid secreted by mast cells is prostaglandin D2 (PGD2), a relatively unstable pro-inflammatory mediator which can be spontaneously converted to 15-deoxy-(Delta12,14)-prostaglandin J2(15d-PGJ2) or enzymatically metabolized to 9α,11β-PGF2 by aldo-keto reductase 1C3 (AKR1C3). In this work, we investigated the possible role of PGD2 and its metabolites in keloids using CRL1762 keloid fibroblasts (KF) and immunohistochemical staining. Our data suggested approximately 3-fold increase of tryptase-positive mast cell count in keloids compared with normal skin. Furthermore, AKR1C3 was overexpressed in the fibrotic area of keloids while relatively weak staining detected in normal skin. Metabolism of PGD2 to 9α,11β-PGF2 by both, KF and normal fibroblasts, was dependent on AKR1C3 as this reaction was attenuated in the presence of the AKR1C3 inhibitor, 2'-hydroxyflavanone, or in cells with decreased AKR1C3 expression. 15d-PGJ2, but not the other tested PGs, inhibited KF proliferation, attenuated KF-mediated collagen gel contraction and increased caspase-3 activation. In addition, treatment with 15d-PGJ2 activated P38-MAPK, induced reactive oxygen species and upregulated superoxide dismutase-1 (SOD-1). Finally, inhibition of P38-MAPK further augmented 15d-PGJ2-induced caspase-3 cleavage and attenuated its effect on SOD-1 transcription. This work suggests that localized dual inhibition of AKR1C3 and P38-MAPK may inhibit keloid progression. Inhibiting AKR1C3 activity may generate oxidative environment due to redirection of PGD2 metabolism towards 15d-PGJ2 while inhibition of P38-MAPK will sensitize keloid cells to ROS-induced apoptosis.

Mechanisms Underlying the Scratching Behavior Induced by the Activation of Proteinase-Activated Receptor-4 in Mice

A role for proteinase-activated receptor-4 (PAR-4) was recently suggested in itch sensation. Here, we investigated the mechanisms underlying the pruriceptive actions of the selective PAR-4 agonist AYPGKF-NH2 (AYP) in mice. Dorsal intradermal (i.d.) administration of AYP elicited intense scratching behavior in mice, which was prevented by the selective PAR-4 antagonist (pepducin P4pal-10). PAR-4 was found to be coexpressed in 32% of tryptase-positive skin mast cells, and AYP caused a 2-fold increase in mast cell degranulation. However, neither the treatment with cromolyn nor the deficiency of mast cells (WBB6F1-Kit(W/Wv) mice) was able to affect AYP-induced itch. PAR-4 was also found on gastrin-releasing peptide (GRP)-positive neurons (pruriceptive fibers), and AYP-induced itch was reduced by the selective GRP receptor antagonist RC-3095. In addition, AYP evoked calcium influx in ∼1.5% of cultured DRG neurons also sensitive to TRPV1 (capsaicin) and/or TRPA1 (AITC) agonists. Importantly, AYP-induced itch was reduced by treatment with either the selective TRPV1 (SB366791), TRPA1 (HC-030031), or NK1 (FK888) receptor antagonists. However, genetic loss of TRPV1, but not of TRPA1, diminished AYP-induced calcium influx in DRG neurons and the scratching behavior in mice. These findings provide evidence that PAR-4 activation by AYP causes pruriceptive itch in mice via a TRPV1/TRPA1-dependent mechanism.

Predomination of IL-17-producing tryptase-positive/chymase-positive mast cells in azoospermic chronic testicular inflammation.

Chronic testicular inflammation and infection have been regarded as important factors in the pathogenesis of azoospermia. As key effector cells in innate and adaptive immune system, mast cells (MCs) were observed in inflammation and autoimmune disease. Furthermore, increased expression of tryptase-positive MCs has been reported in testicular disorders associated with male infertility/subfertility. However, little is known about the potential relationship between MCs and chronic testicular inflammation in azoospermic patients. Moreover, the preferential expression of MCs' subtypes in testis of these patients is still far from being understood. Thus, this study aimed to investigate characteristics of testicular MCs as well as their subtypes in azoospermic men with chronic testicular inflammation (AZI, n=5) by immunohistochemical techniques. Our results showed significant increase of MCs in AZI, and more importantly, considerable numbers of tryptase-positive/chymase-positive MCs could also be demonstrated in AZI, when compared to control groups representing azoospermia without chronic testicular inflammation (AZW, n=5) and normal spermatogenesis (NT, n=5) respectively. Most interestingly, immunofluorescence staining revealed autoimmune-associated interleukin (IL)-17-producing MCs in AZI, whereas co-expression of MC markers with tumour necrosis factor (TNF)-α, IL-10 and IL-1β could not be detected. In conclusion, AZI is associated with significant increase of tryptase-positive/chymase-positive MCs expressing IL-17, and these MCs might contribute to the pathogenesis of AZI.

Density of Tryptase-Positive Mast Cells Correlated with the Presence of H. pylori in Gastric Neoplasia.

Gastric cancer continues to be a platoon leader of mortality causes. A significant number of recent studies show direct or indirect involvement of mast cells (MC), with a complex role both pro- and anti-tumor growth. To objectify the correlations between expression of MC and presence of Helicobacter pylori (HP) infection depending on neoplastic nature of the gastric damage. The study was carried out on archival samples of gastric wall from 30 patients with gastric cancer versus 30 age and sex-matched subjects with gastric surgery for non-neoplastic diseases. The inclusion criteria for the case group were histologically proven stage T3/T4 malignancies with regional lymph node metastases. For each case of the study group, distribution and number of MC tryptase positive (DMC-TP) were analyzed in five different areas from the same gastrectomy specimen: intratumor area, deep and side tumor invasion front, normal gastric tissue sample 5-10 cm or more distant from the tumor and furthest resection margin. Independently of HP infection, the study recorded a significantly lower value of DMC-TP in male patients. In regions with inflammatory lesions and preneoplastic changes and in control cases with non-gastric neoplasia, the DMC-TP level was higher than controls with HP-related inflammatory pathology, thus removing bacterial etiology from the forefront of MC mobilizing causes. The presence of H. pylori infection was not found to cause significant changes in terms of mobilizing mast cells in the gastric wall with advanced tumors, with minimal stage III TNM.

Abstract 1091: A new image processing approach for functional context-based analysis of tryptase positive mast cells in cutaneous T-cell lymphomas

Abstract Quantification data on mast cells is scarce in primary cutaneous T-cell lymphomas (CTCL), a heterogeneous group of non-Hodgkin lymphomas with initial presentation in the skin. The aim of the study was to develop a new whole-slide in-silico analysis method for immunohistochemistry stained skin sections. The design of the analysis method was focused on results about structural context of the cell location distribution and cell morphometry linked to mast cell activation states. Immunohistochemistry staining with a monoclonal anti-mast cell tryptase antibody was performed on paraffin embedded biopsies from patients with different CTCL subtypes and controls (normal skin, inflammatory skin diseases),while hematoxylin was used for counter staining. Slides were scanned with a TissueFAXS 200 Cytometer (TissueGnostics GmbH, Vienna). Whole-slide digital images were analyzed using StrataQuest 5.0 Advanced (TissueGnostics, Vienna). Hematoxylin+ cell nuclei and tryptase+ cells (TRYP+) objects were automatically detected using the available analysis modules with adaptive segmentation of color-deconvoluted images. Mast cells were first selected as brown-positive cells in a peri-nuclear compartment, then further stratified depending on the spatial distribution of brown-positive dots inside the cellular compartment. In an additional analysis layer, an algorithm pipeline for the identification of the epidermis / dermis area was assembled. Density-based CTCL areas were segmented in a third independent pipeline. Inside dermis, two additional CTCL-proximity masks were defined at 0-30μm away from CTCL (P1 mask), as well as in the 30-60μm interval (P2 mask). Typically, there were more mast cells inside CTCL areas than in P1, which in turn had less than the P2 mask. This distribution was especially noticed in Mycosis fungoides(MF) IIB, where CTCL had 2-3 times more mast cells than P1 mask had. However, this trend was not consistent in all types of lymphoma. Interestingly, MF IIA had a different distribution showing more mast cells in P1 than in CTCL areas. The new algorithms provided a rich data insight on functional context-based characteristics and propose new surrogate markers for further characterization of CTCL. The analysis time needed for statistically relevant large whole-slide tissue sections was drastically reduced when using the computer-aided approach when compared against full manual annotation and counting. Moreover, distance assessment and morphometry parameter quantification for each cell are only feasible in in-silico approaches. Note: This abstract was not presented at the meeting. Citation Format: Radu Rogojanu, Johanna Eder, Waltraud Jerey, Gabriele Klosner, Verene Paulitschke, Isabella Ellinger, Theresia Thalhammer, Dan Kolmer, Franz Trautinger. A new image processing approach for functional context-based analysis of tryptase positive mast cells in cutaneous T-cell lymphomas. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1091. doi:10.1158/1538-7445.AM2015-1091

High density of tryptase-positive mast cells in patients with multiple myeloma: correlation with parameters of disease activity.

Multiple myeloma (MM) is a plasma cell neoplasm characterized by bone marrow infiltration from malignant plasma cells. Mast cells play an important role in inflammation and angiogenesis in malignant diseases. The aim of the study was to evaluate the mast cell density in bone marrow of untreated MM patients with markers of disease activity such as serum interleukin-6 (IL-6), B2M, and C-reactive protein (CRP), the grade of bone marrow infiltration, and the levels of produced paraprotein. We studied 86 newly diagnosed MM patients (46 males, 40 females, mean age 59 ± 13.7 years). Thirty of them reached plateau phase after chemotherapy and 20 healthy volunteers. According to the criteria of International Staging System (ISS) staging system, 23 patients had stage I, 30 had stage II, and 33 had stage III. The serum concentrations of CRP, B2M, and IL-6, and the mast cell density (MCD) values were significantly higher in MM patients' group (1.6 ± 1.8, 4.3 ± 2.9, 7.1 ± 5.1, and 9 ± 4.8), in comparison with those found in control group (0.4 ± 0.1, 1.5 ± 0.6, 1.1 ± 0.5, and 1.9 ± 0.7; p < 0.001 in all the cases). Significant differences were found between the grade of infiltration in bone marrow, and the paraprotein values in patients' serum before and after chemotherapy. Furthermore, there was a significant correlation between the MCD values and the prognostic markers CRP (r = 0.452, p < 0.0001), IL-6 (r = 0.475, p < 0.0001), bone marrow infiltration (r = 0.333, p < 0.0002), and serum paraprotein levels(r = 0.221, p < 0.04). High MCD values strengthen the hypothesis that mast cells participate in the pathogenesis of disease progression and may be used as an indicator of the disease activity.

IL-17A Is Elevated in End-Stage Chronic Obstructive Pulmonary Disease and Contributes to Cigarette Smoke-induced Lymphoid Neogenesis.

End-stage chronic obstructive pulmonary disease (COPD) is associated with an accumulation of pulmonary lymphoid follicles. IL-17A is implicated in COPD and pulmonary lymphoid neogenesis in response to microbial stimuli. We hypothesized that IL-17A is increased in peripheral lung tissue during end-stage COPD and also directly contributes to cigarette smoke-induced lymphoid neogenesis. To characterize the tissue expression and functional role of IL-17A in end-stage COPD. Automated immune detection of IL-17A and IL-17F was performed in lung tissue specimens collected from patients with Global Initiative for Chronic Obstructive Lung Disease stage I-IV COPD, and smoking and never-smoking control subjects. In parallel, Il17a(-/-) mice and wild-type control animals were exposed to cigarette smoke for 24 weeks, and pulmonary lymphoid neogenesis was assessed. Tissue expression of IL-17A and IL-17F was increased in COPD and correlated with lung function decline. IL-17A was significantly elevated in severe to very severe COPD (Global Initiative for Chronic Obstructive Lung Disease III/IV) compared with both smokers and never-smokers without COPD. Although CD3(+) T cells expressed IL-17A in very severe COPD, most IL-17A(+) cells were identified as tryptase-positive mast cells. Attenuated lymphoid neogenesis and reduced expression of the B-cell attracting chemokine C-X-C motif ligand (CXCL) 12 was observed in cigarette smoke-exposed Il17a(-/-) mice. CXCL12 was also highly expressed in lymphoid follicles in COPD lungs, and the pulmonary expression was significantly elevated in end-stage COPD. IL-17A in the peripheral lung of patients with severe to very severe COPD may contribute to disease progression and development of lymphoid follicles via activation of CXCL12.

Increased Expression of Thymic Stromal Lymphopoietin and Its Receptor in Kimura's Disease

Objective: The objective of this study was to investigate the expression of thymic stromal lymphopoietin (TSLP) and TSLP receptor (TSLPR) in Kimura's disease (KD). Methods: Using parotid gland tissues from KD patients and control subjects, we quantified the expression levels of mRNA for TSLP, interleukin (IL)-25, IL-33, and their receptors by massively parallel sequencing. We also performed immunohistochemical analysis of TSLP and TSLPR, and counted cells immunoreactive for these proteins by the polymer immunocomplex and double immunofluorescence methods. Results: The levels of mRNA for TSLP, TSLPR, and IL-25R, but not IL-25, IL-33, or IL-33R, were significantly elevated in parotid gland tissues from the KD group as compared to the control group. Immunohistochemical analysis revealed that TSLP- and TSLPR-positive cells were significantly increased in number in parotid gland tissues from KD patients. Double immunofluorescence staining showed that TSLP and TSLPR were localized mainly in CD68-positive macrophages and tryptase-positive mast cells, respectively. Conclusions: Overexpression of TSLP and TSLPR might contribute to the pathogenesis of KD through interactions between macrophages and mast cells. Regulation of TSLP/TSLPR signaling may be a potential therapeutic approach for KD.

Mast cells infiltration and decreased E-cadherin expression in ketamine-induced cystitis

BackgroundKetamine is a controlled substance and often illegally used as a recreational drug primarily by young adults. Increasing ketamine abusers associated with lower urinary tract symptoms have been reported at hospitals in recent years. Here we used a murine model to explore the changes of bladder in order to elucidate its pathogenesis. MethodsICR mice were randomly distributed into control and ketamine groups and received daily intraperitoneal injection of saline and ketamine (30mg/kg), respectively. The bladders were excised and processed for histology at 4, 8 and 12 weeks. Tryptase and E-cadherin were investigated by immunohistochemistry in bladder tissues from ketamine-treated and control mice to assess the mast cell activation and junction protein expression. ResultsAfter ketamine treatment, the bladder changed to be hyperemic, inflamed, and with more fissures in mucosa. Compared with control group, the number of tryptase-positive mast cells significantly increased, which was 6.98±2.89 and 23.00±6.48cells per field (100×) at 8 and 12 weeks, respectively (P=0.016 and P=0.003, respectively). Additionally, the expression of E-cadherin in ketamine-treated mice bladder tissue was significantly lower than that in the control tissues, P<0.001. ConclusionsIncreased mast cells in bladder wall and downregulated expression of E-cadherin junction protein in epithelial cells were probably associated with interstitial inflammation and fissures in mucosa. It implied that ketamine induced an interstitial cystitis.

Increased Numbers of Tryptase-Positive Mast Cells in the Healthy and Sun-Protected Skin of Tobacco Smokers

Background: Tobacco smoking may cause skin aging through mast cell proteinases. Objective: To compare the numbers of mast cells showing tryptase and chymase in the healthy-looking skin of smokers and non-smokers. Methods: The study subjects consisted of 80 males, 42 of whom were smokers and 38 non-smokers. A skin biopsy from the medial arm was processed for immunohistochemical staining of tryptase and chymase, as well as chymase inhibitors alpha-1-proteinase inhibitor (alpha-1-PI) and alpha-1-antichymotrypsin (alpha-1-AC). Results: The number of tryptase⁺ mast cells was significantly higher in the smoker group (84 ± 32 cells/mm²) than in the non-smoker group (70 ± 32 cells/mm²) (p = 0.044). Likewise, the number of chymase⁺ mast cells was higher in the smoker group (89 ± 20 vs. 80 ± 22 cells/mm²), though statistical significance was not reached (p = 0.07). No significant difference was observed in alpha-1-PI⁺ and alpha-1-AC⁺ cells. Conclusion: Especially tryptase, but probably also chymase, may have an influence on the skin of smokers, such as wrinkling and aging.

Renal interstitial mast cell counts differ across classes of proliferative lupus nephritis.

Systemic lupus erythematosus frequently involves the kidneys leading to significant morbidity and mortality. It is classified according to glomerular involvement pattern but tubulointerstitial lesions are also important for progression and prognosis, as seen in other kidney glomerular diseases. One of the cell types which participate in this process are mast cells. The aim of the study was to analyze the counts of tryptase-positive and chymase-positive mast cells in lupus nephritis classes II, III and IV. Material consisted of 42 renal biopsies from patients with lupus nephritis; 11 class II, 9 class III and 22 class IV. Chymase- and tryptase-containing cells were stained by immunohistochemistry and counted microscopically. Mean count of chymase-positive mast cells was 9.8/10 high power fields (hpf) for the whole group, 4.66 for class II, 11.89 for class III, and 11.51 for class IV. The mean count of tryptase-positive cells was 18.6/10 hpf for the whole group, 7.65 for class II, 25.57 for class III, and 21.23 for class IV. The differences between lupus nephritis classes were significant both for chymase- and tryptase-positive cells. Tryptase- but not chymase-positive cell counts showed a correlation with the creatinine level (R = 0.35). These results suggest that mast cells are involved to a different degree in the pathogenesis of lupus nephritis depending on the class of the disease.

Altered immunohistochemical expression of mast cell tryptase and chymase in the pathogenesis of oral submucous fibrosis and malignant transformation of the overlying epithelium.

Mast cells (MCs) expressing serine proteases; tryptase and chymase, are associated with fibrosis in various diseases. However, little is known about their involvement in oral submucous fibrosis (OSF). Our goal was to evaluate the role of MC tryptase and chymase in the pathogenesis of OSF and its malignant transformation. Immunohistochemical expression of MC tryptase and chymase was evaluated in 20 cases of OSF, 10 cases of oral squamous cell carcinoma (OSCC) and 10 cases of healthy controls. Subepithelial zone of Stage 1 and 2 while deep zone of Stage 3 and 4 OSF demonstrated increased tryptase positive MCs. OSCC revealed a proportionate increase in tryptase and chymase positive MCs irrespective of areas of distribution. An altered balance in the subepithelial and deep distribution of tryptase and chymase positive MCs play an important role in the pathogenesis of OSF and its malignant transformation.

Mast cells impair host defense during murine Streptococcus pneumoniae pneumonia.

Streptococcus pneumoniae is the most common causative pathogen in community-acquired pneumonia. Mast cells (MCs) are located mainly at the host-environment interface where they function as sentinels. Our goal was to study the role of MCs during pneumonia caused by S. pneumoniae. Lung tissue of patients who had died from pneumococcal pneumonia or a nonpulmonary cause was stained for MCs and tryptase. Wild-type (WT) and MC-deficient (Kit(W-sh/W-sh)) mice were observed or sacrificed after induction of pneumonia by intranasal inoculation of S. pneumoniae. In separate experiments, WT mice were treated with doxantrazole or cromoglycate, which are MC stabilizing agents. The constitutive presence of tryptase-positive MCs was reduced in affected lungs from pneumonia patients. Kit(W-sh/W-sh) mice showed a prolonged survival during the first few days after median lethal dose (LD)100 and LD50 infection, while overall mortality did not differ from that in WT mice. Relative to WT mice, Kit(W-sh/W-sh) mice showed reduced bacterial counts with less bacterial dissemination to distant organs and less inflammation. Neither doxantrazole nor cromoglycate influenced antibacterial defense or inflammatory responses after airway infection with S. pneumoniae. MCs exhibit an unfavorable role in host defense during pneumococcal pneumonia by a mechanism independent of degranulation.

Antagonistic Effects Of Ozone (O3) Exposure and Glucocorticoid Treatment On Airway Hyperresponsiveness (AHR) and Surfactant Protein D (SP-D) Production In Mice

S U N D A Y 559 Bronchial Mast Cell Markers and Clinical Asthma Severity In Steroid Refractory Asthmatics Dr. Mandeep Hundal, MD, Dr. Katherine N. Cahill, MD, Robert Pedicini, Allison Crosby-Thompson, Stefanie Dutile, Usha Govindarajulu, PhD, Dr. Kartik Shenoy, MD, Dr. Mark Dransfield, Dr. Emily DiMango, Dr. Serpil C. Erzurum, MD, Dr. Mario Castro, MD, MPH, Dr. Nizar N. Jarjour, MD, Dr. Howard Katz, PhD, Dr. Joshua A. Boyce, MD, FAAAAI, Dr. Elliot Israel, MD, FAAAAI; Brigham and Women’s Hospital, Boston, MA, Brigham and Women’s Hospital, Division of Rheumatology, Immunology and Allergy, Boston, MA, Temple University School of Medicine, University of Alabama School of Medicine, AL, Columbia University, New York, NY, Department of Pathobiology, Cleveland Clinic, Washington University School of Medicine, St. Louis, MO, University of Wisconsin School of Medicine and Public Health, Madison, WI. RATIONALE: Mast cells are thought to play a significant role in asthma and are resistant to corticosteroid effects. Bronchial mast cells express chymase, tryptase and the c-kit receptor. We investigated the relationship between these mast cell markers and clinical asthma severity measurements in patients with steroid refractory asthma. METHODS: We recruited adult asthmatics with severe asthma symptoms (ACQ>1.5) on continuous treatment with high-dose inhaled corticosteroids (ICS) and at least one additional controller therapy. All subjects had confirmed airway hyperresponsiveness with methacholine challenge (PC20< 10 mg/ml). Endobronchial biopsies were obtained from these subjects (n527) andmast cells were immunostained for tryptase and chymase. Bronchoalveolar lavage (BAL) fluid (n528) was processed and c-kit mRNAwas measured in the BAL cell pellet using qPCR. RESULTS: Intramucosal chymase positive mast cell numbers show a positive correlation with log PC20 (r50.45, p50.02); suggesting decreasing methacholine hyperresponsiveness with increasing chymase positive mast cells. Intramucosal tryptase positive mast cell counts did not show any significant association with log PC20. FEV1/FVC ratio had a negative correlation with c-kit mRNA in the BAL cell pellet (r5-0.37, p50.05). CONCLUSIONS: Increased c-kit mRNA in BAL is related to worsening airway obstruction suggestingmast cell activity contributes to poor asthma control in steroid unresponsive asthmatics. It has been previously reported that chymase positive mast cells in severe asthma correlate with better lung function. The negative correlation between chymase positive mast cells and airway hyperresponsiveness in our study supports a unique pathobiological role for this mast cell phenotype in severe asthmatics.

Mast Cells in Irritable Bowel Syndrome and Ulcerative Colitis: Function Not Numbers Is What Makes All the Difference

Data obtained from animal and human studies support the existence of mast cells (MC) in the gastrointestinal (GI) tract, where they are considered important for the control of luminal parasites and possibly other microorganisms. MC are also implicated in food allergies, GI inflammation, and functional GI diseases, including irritable bowel syndrome (IBS) [1]. MC density may be increased in inflammatory bowel disease (IBD) and IBS, although such studies have yielded variable and sometimes contradictory results, likely due to methodological problems such as sampling issues, poorly characterized MC identification methodology, and lack of adequate documentation of disease correlates. There is no question that MC numbers are likely to be easier to identify and count in lesional areas as they may be present in IBD. MC density in the terminal ileum had previously been reported to be significantly increased in patients with IBS, even though MC abundance only correlated weakly with IBS symptoms, and, in some cases, a decreased density of colonic c-kit-positive in IgEor IgG-stained MC, was reported [2], even though IgEor IgG-staining is not an index of MC activation. In the paper by Choi et al. [3] published in this issue of Digestive Diseases and Sciences, the authors analyzed intestinal MC density in: (a) diverse patient cohorts, including diarrhea predominant-IBS (D-IBS), ulcerative colitis (UC) in remission, mild UC, and in healthy controls; (b) random colonic biopsies; (c) different colonic segments; and (d) mucosal MC and lamina propria/intra-epithelial T lymphocytes. The results are important because MC number was significantly increased in 97.6 % of D-IBS patients, intra-epithelial lymphocytes (IEL) were increased in 92.8 %, and lamina propria lymphocytes (LPL) were increased in 81.9 %. Moreover, even though the numbers of immune cells were even higher in some post-infectious (PI)-IBS patients, the remaining D-IBS patients had a significantly higher number of these cells compared with controls. Immunochemically identified were tryptase-positive MC and CD3-positive T cells (and not for all lymphocytes, as the authors stated). All publications to date, including the one by Choi et al. [3], did not report MC activation, which, according to some, is more important than actual numbers [4]. For instance, tryptase staining underestimates the number of degranulated MC, since released secretory granule tryptase does not stain. One way to identify degranulated MC is to stain for c-kit (CD117), the surface MC receptor for stem cell factor. Nevertheless, since mediator secretion can also occur without degranulation [5], MC activation can best be identified either by ultrastructural appearance T. C. Theoharides (&) Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA e-mail: theoharis.theoharides@tufts.edu

Desmoid tumor-associated pain is dependent on mast cell expression of cyclooxygenase-2

BackgroundThis study aimed to investigate the expression profile of cyclooxygenase-2 (COX-2) in desmoid tumor specimens and to evaluate the correlation of intratumoral COX-2 expression with pain status.MethodsSixteen patients with histologically proven desmoid tumors who attended our institution between 2003 and 2010 were enrolled in this study. COX-2 protein expression in desmoid tumors was determined by immunohistochemistry. COX-2 - positive cells had similar morphology to that of mast cells, and therefore, immunohistochemical staining for tryptase was performed in co-localized sections. The number of COX-2 -positive cells in 10 consecutive fields was counted at 400× magnification. Patients were stratified into 2 groups according to the number of COX-2- positive cells, the COX-2 -positive group (≧10 COX-2 -positive cells) and the COX-2 -negative group (<10 COX-2 -positive cells). The prevalence of painful tumors was compared between the 2 groups.ResultsCOX-2 was expressed in 9 patients (56%). COX-2 proteins were expressed not in tumor cells but in tryptase-positive mast cells in the stroma of desmoid tumors. 6 of 9 patients in COX-2 -positive group had painful tumors. This difference was statistically significant according to the chi-squared test (p = 0 .036), suggesting a positive correlation between COX-2 expression and tumor-associated pain.ConclusionsOur results indicated that COX-2 secretion from mast cells modulates desmoid tumor-associated pain. In addition, mast cells may at least in part contribute to the pathogenesis of desmoid tumors.Virtual slideThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1490389349103056.

Comparison of Mast Cells and Inflammatory Cells within Periapical Lesions and Comparison of Degranulated Mast Cells Between Fibrous and Inflamed Area in Radicular Cysts: An Immunohistochemical Study.

The role of mast cells as the key effector of allergic inflammation, anaphylactic inflammatory reactions and in the pathogenesis of chronic inflammation, is well-known. The present study is adopted to compare mast cells and inflammatory cells within periapical granuloma and cysts and localize the mast cells and quantify their number in the periapical cysts so as to propose a role of mast cells in the pathogenesis of this lesion. Biopsy specimens of 30 periapical lesions were stained with hematoxylin-eosin, and immunohistochemical Mast Cell Tryptase from Bio SB (IHC detection system kit) antibody. The tryptase positive mast cells and mononuclear inflammatory cells were counted in 10 consecutive high power fields (100X) using the binocular microscope from Motic attached to a computer with Motic Advanced Images 3.2 software. Comparative microscopic analysis indicated that periapical cyst shows more percentage of mast cells and less percentage of inflammatory cell than periapical granuloma (comparison of mean and standard deviation of total number of mast cells and inflammatory cells, mast cells 3.15±1.39 in the granuloma group and 4.43±1.91in the cyst group, inflammatory cells, 67.11±1.2 in the granuloma group and 52.66±0.8 in the cyst group). Numerous degranulated mast cells were observed in the fibrous wall than the inflammatory infiltrate of the periapical cysts. The mean and standard deviation of degranulated mast cells between the inflammatory and fibrous zone within the cyst group, being 0.95±1.10 and1.68±1.34 respectively. The values varied significantly between the two zones. The number of inflammatory cells in the cyst group is less than periapical granuloma and total number of mast cells in the cyst group is more as compared to periapical granuloma. The degranulated cells were quantified and they were higher in the fibrous area of the cysts than the inflammatory zone. This study could support the fact that the various mediators released on degranulation play a role in the connective tissue remodeling, chronicity and expansion of the periapical lesion.

Increased levels of lysosomal cysteinyl cathepsins in human varicose veins: A histology study

Varicose veins are a major chronic venous disease characterised by extensive remodelling of the extracellular matrix architecture in the vascular wall. Although matrix metalloproteinases have been implicated in these pathologic events, little is known about the functional relevance of other protease family members. Here, we studied the distribution of lysosomal cysteine proteases, cathepsins B, L, K, and S, and their endogenous inhibitor, cystatin C, in long saphenous vein specimens from nine normal donors and 18 patients with varicose veins (VVs). Immunohistochemical analysis demonstrated increased levels of cathepsins L, K, B, and S and reduced levels of cystatin C in VVs. This imbalance between cysteinyl cathepsins and cystatin C may favour VV remodelling. To investigate the inflammatory mechanism of their expression, we examined a detailed inflammatory cell profile in VVs, including macrophages, T lymphocytes, and mast cells. Increased numbers of CD3-positive T cells and tryptase-positive mast cells were found in VVs, and enhanced levels of cysteinyl cathepsins were detected from lesion CD3-positive T cells, chymase-positive mast cells, endothelial cells, and smooth-muscle cells. Elevated cathepsins, and their co-localisation to infiltrated inflammatory cells and to vascular cells, suggest that these proteases participate in extracellular matrix degradation in response to inflammation during VV pathogenesis.