Staining For Mast Cell Tryptase Research Articles

C-kitpos cells in the human left atrial appendage

BackgroundSubpopulations of myocardial c-kitpos cells have the ability to stimulate regeneration in ischemic heart disease by paracrine effects. The left atrial appendage (LAA), which is easy accessible during cardiac surgery, may represent a perfect source for c-kitpos cell extraction for autologous cell therapies in the living human. So far, frequency and distribution of c-kitpos cells in LAA are unknown. MethodsLAAs of patients who underwent cardiac surgery due to coronary artery disease (coronary artery bypass graft, CABG), valvular heart disease or both and of two body donors were examined. Tissue was fixed in 4 % paraformaldehyde, embedded in paraffin, dissected in consecutive sections and stained for c-kitpos cells. In parallel, grade of fibrosis, amount of fat per section and cells positive for mast cell tryptase were examined. ResultsWe collected 27 LAAs (37.0 % female, mean left ventricular ejection fraction 50.4 %, 63.0 % persistent atrial fibrillation (AF)). Most of the patients underwent combined CABG and valve surgery (51.9 %). C-kitpos cells were detected in 3 different regions: A) Attached to the epicardial fat layer, B) close to vascular structures and C) between cardiomyocytes. C-kitpos cells ranged from 0.05 c-kitpos cells per mm2 to 67.5 c-kitpos cells per mm2. We found no association between number of c-kitpos cells and type of AF, amount of fibrosis or amount of fat. Up to 72 % of c-kitpos cells also showed a positive staining for mast cell tryptase. ConclusionC-kitpos cells are frequent in LAAs of cardiovascular patients with a rather homogenous distribution throughout the LAA. The LAA can therefore be considered as a source for extraction of a reasonable quantity of autologous cardiac progenitor cells in the living human patient.

Utility of major basic protein, eotaxin-3, and mast cell tryptase staining for prediction of response to topical steroid treatment in eosinophilic esophagitis: analysis of a randomized, double-blind, double dummy clinical trial.

Inflammatory factors in eosinophilic esophagitis (EoE), including major basic protein (MBP), eotaxin-3 (EOT3) and mast cell tryptase (TRP), may predict treatment response to topical corticosteroids (tCS). We aimed to determine whether baseline levels of these markers predict response to tCS for EoE. To do this, we analyzed data from a randomized trial comparing two topical steroids for treatment of newly diagnosed EoE (NCT02019758). A pretreatment esophageal biopsy was stained for MBP, EOT3, and TRP to quantify tissue biomarker levels (cells/mm2). Levels were compared between histologic responders (<15 eos/hpf) and nonresponders (the primary outcome), and endoscopic responders (EREFS<2) and nonresponders. Complete histologic response (<1 eos/hpf) was also assessed, and area under the receiver operator characteristic curve (AUC) was calculated. We also evaluated whether baseline staining predicted symptom relapse in the trial's off-treatment observation phase. Baseline samples were evaluable in 110/111 subjects who completed the randomized trial. MBP levels were higher in nonresponders (n = 36) than responders (704 vs. 373 cells/mm2; P = 0.007), but EOT3 and TRP levels were not statistically different. The combination of all three stains had an AUC of 0.66 to predict response. For complete histologic response, baseline TRP levels were higher in nonresponders (n = 69) than responders (370 vs. 268 mast cells/mm2; P = 0.01), with an AUC of 0.65. The AUC for endoscopic response was 0.68. Baseline staining did not predict symptom recurrence after remission. Pretreatment MBP, EOT3, and TRP levels were not strongly or consistently associated with histologic or endoscopic response to topical steroids. While elevated TRP levels may be associated with nonresponse compared with complete response, the magnitude and predictive utilities were modest. Novel methods for predicting steroid response are still required.

Clinical, Histologic, and Molecular Analysis of Differences Between Erythematotelangiectatic Rosacea and Telangiectatic Photoaging.

Facial erythema and telangiectasia are commonly associated with the erythematotelangiectatic subtype of rosacea (ETR). It is important for clinicians to recognize that these findings can also be associated with a subtype of photoaging, which we term telangiectatic photoaging (TP). To demonstrate that ETR and TP are distinct dermatologic disorders. A case-control observational study comparing clinical, histologic, and gene expression features of 26 participants with ETR, 20 with TP, and 11 age- and sex-matched controls in the Program for Clinical Research in Dermatology at University of Michigan. Findings of clinical history and examination, light and electron microscopy, immunohistochemical analyses, and real-time quantitative reverse-transcriptase polymerase chain reaction gene expression. Transient erythema was greater in the ETR group (38% graded moderate to severe) than in the TP (0%; P < .001) and control groups (0%; P = .002). Nontransient erythema was also greater in the ETR group (50% graded moderate to severe) than in the TP (25%; P = .03) and control groups (0%; P < .001). Participants with ETR tended to have erythema and telangiectasia primarily on the central face (79%), whereas those with TP tended to have more lateral involvement (57%; P < .001). Those with ETR had significantly less clinical evidence of photodamage (0% graded 6-8 on a photonumeric scale) than those with TP (40% graded 6-8; P = .01). Histologically, there was less evidence of photodamage in ETR than in TP, which had wispy collagen and solar elastosis surrounding blood vessels. Immunohistologic analysis demonstrated greater geometric mean immunostained area by mast cell tryptase staining in ETR samples (0.018%) than in TP (0.004%; P = .01) or control samples (0.001%; P < .001) but no increase in mast cell number, indicative of greater mast cell degranulation. Gene expression of matrix metalloproteinase-3 was 4-fold greater in ETR samples than in TP samples (P = .004) and 5-fold higher than in control samples (P = .004). Gene expression of the neuropeptides calcitonin gene-related peptide (CGRP-α) and substance P was significantly increased in ETR compared with TP (9-fold [P < .001] and 5-fold [P = .002], respectively) and control samples (10-fold [P < .001] and 28-fold [P < .001], respectively). Telangiectatic photoaging is characterized by less transient and nontransient erythema, a more lateral distribution of erythema and telangiectasia, less neurogenic mast cell activation, and less MMP-mediated matrix remodeling than ETR. These data demonstrate that TP is a distinct clinical entity from ETR that can be distinguished on the basis of clinical, histologic, and gene expression findings.

Mast Cells and Histamine: Do They Influence Placental Vascular Network and Development in Preeclampsia?

The physiological course of pregnancy is closely related to adequate development of the placenta. Shallow invasion of trophoblast as well as decreased development of the placental vascular network are both common features of preeclampsia. To better understand the proangiogenic features of mast cells, in this study we aim to identify the potential relationship between the distribution of mast cells within the placenta and vascular network development. Material and Methods. Placentas from preeclampsia-complicated pregnancies (n = 11) and from physiological pregnancies (n = 11) were acquired after cesarean section. The concentration of histamine was measured, and immunohistochemical staining for mast cell tryptase was performed. Morphometric analysis was then performed. Results. We noticed significant differences between the examined groups. Notably, in the preeclampsia group compared to the control group, we observed a higher mean histamine concentration, higher mast cell density (MCD), lower mean mast cell (MMCA) and lower vascular/extravascular (V/EVT) index. In physiological pregnancies, a positive correlation was observed between the histamine concentration and V/VEVT index as well as MCD and the V/VEVT index. In contrast, a negative correlation was observed between MMCA and the V/EVT index in physiological pregnancies. Conclusions. Based on the data from our study, we suggest that a differential distribution of mast cells and corresponding changes in the concentration of histamine are involved in the defective placental vascularization seen in preeclamptic placentas.

The lack of correlation between mast cells and microvessel density with pathologic feature of renal cell carcinoma

The growth of solid tumors requires angiogenesis. Evidence indicates that mast cells (MCs) play an important role in tumor angiogenesis but results are not definitive. The aim of this study is to investigate the possible effects of angiogenesis and the presence of MCs on the prognosis of renal cell carcinoma (RCC). The study involved 40 patients with RCC (24 men and 16 women who were treated with radical nephrectomy between 1995 and 2006, at our institution. The routine mast cell tryptase staining method was used to assess the MCs in both normal tissue and tumoral tissue. The immunohistochemical staining for CD34 antigen was used for determination of microvessel density. The relation between MC count and tumor status such as tumor stage, size, grade, and other clinicopathologic parameters in RCC were evaluated in this study. We found no relationship between the number of MCs and patient age, sex, tumor stage, grade, size. No association was noted between angiogenesis and either patient sex or age, tumor size, stage, and grade. No statistically significant correlation was found between the number of MCs and microvessel density in RCC (P-value = 0.45) but the max value of MCs and MVD were in clear cell carcinoma. The MC count was not associated with tumor status such as tumor stage, size, grade, and other clinicopathologic parameters, however, MCs may be related to tumor angiogenesis and acceleration of tumor growth in RCC and therefore need further evaluation in RCC.

Allergic fungal sinusitis: An immunohistologic analysis

Background: Allergic fungal sinusitis is a noninvasive form of fungal sinusitis that has recently been delineated as a distinct clinicopathologic entity. It is increasingly recognized as a cause of chronic sinusitis, with the primary causative agents being members of the Dematiaceae fungus family. Although its immunopathogenesis has not been elucidated, the eosinophil is a prominent inflammatory cell on histologic examination. Objective: We sought to characterize the involvement of eosinophils in sinus tissue and accompanying mucin from patients with allergic fungal sinusitis. As a comparison, neutrophil and mast cell involvement was also evaluated in the same group of patients. Methods: Tissue specimens from 8 patients with allergic fungal sinusitis, along with 8 nasal polyp specimens from patients without allergic fungal sinusitis, were stained by using indirect immunofluorescence for eosinophil granule major basic protein (MBP). Neutrophil elastase and mast cell tryptase staining was also performed on the same allergic fungal sinusitis and nasal polyp tissues. Results: MBP was diffusely localized within the mucin, showing intense staining at the periphery and variable staining of degenerated cell clusters throughout. Extracellular MBP in the mucin was strikingly greater than intact eosinophil staining. Diffuse extracellular neutrophil elastase was also present in the mucin. Mucinous areas showed no tryptase localization. Adjacent nonmucinous areas of respiratory mucosa showed predominantly cellular staining with eosinophil MBP, neutrophil elastase, and mast cell tryptase. MBP staining of nasal polyps showed a predominantly cellular pattern with focal areas of extracellular deposition. Conclusions: Given the known toxicities of eosinophil granule MBP and neutrophil elastase, their extracellular presence supports the contribution of these proteins in the pathogenesis of allergic fungal sinusitis and further indicates that eosinophil and neutrophil activation occurs in the disease. (J Allergy Clin Immunol 2000;106:1096-101.)

Blunted hypoxic pulmonary vasoconstrictive response in the rodent Ochotona curzoniae (pika) at high altitude.

To investigate the possible mechanisms of adaptation to chronic hypoxia in the pulmonary circulation, we made direct measurements of pulmonary arterial pressure (Ppa) in 10 awake pika rodents that were transported to Xining, People's Republic of China (altitude 2,260 m) after being captured at 4,300 m and in 10 Wistar rats in a decompression chamber (simulated altitudes of 4,300 and 5,000 m) in Xining. Ppa was obtained at 1 h of exposure to each simulated altitude. The histology and immunohistochemistry of the lung tissues were also studied. Ppa in the pikas after the 4,300- and 5,000-m altitude exposures did not significantly increase, whereas in the rats Ppa rose significantly. Mean changes in Ppa from 2,260 to 4,300 and 5,000 m were 1.48 +/- 0.49 and 4.80 +/- 0.67 mmHg in the pikas and 10.38 +/- 3.36 and 19.10 +/- 2.28 mmHg in the rats. The ratio of right ventricular to left ventricular plus septal weight in the pikas and rats was 0.22 and 0.45, respectively. The pikas maintained levels of Hb, hematocrit, and 2,3-diphosphoglycerate lower than those of the rats. The percent wall thickness of the small pulmonary arteries in the pikas and rats was 9.22 and 27.21%, respectively, and it was well correlated with the degree of Ppa in both groups. Mast cells were observed in the lungs of the rats (7.1 +/- 0.33 cells/mm2) but not in the pikas. There was highly positive staining for mast cell tryptase and transforming growth factor-beta around pulmonary vessels in the rats, whereas no demonstrable reaction was observed in the pikas. We conclude that the pika has adapted to high altitude by losing hypoxic pulmonary vasoconstriction and thin-walled pulmonary arterioles.

Mast cell distribution, activation, and phenotype in atherosclerotic lesions of human carotid arteries.

Immunohistochemical staining for mast cell tryptase and chymase was used to examine the distribution, activation, and tryptase/chymase phenotype of mast cells (MCs) in 250 samples of atherosclerotic lesions (type I to VI) of human carotid arteries. Dual immunolocalization and histochemical techniques were used to identify the associations of MCs with macrophages, smooth muscle cells, and extracellular matrix components. Whereas normal carotid arteries contained very few MCs within the intima, atherosclerotic lesions showed increased MC numbers with variable focal accumulations. MCs were identifiable from the earliest stages of atherosclerosis, and especially at the shoulder regions of the fully formed atheroma. They were observed in close association with macrophages (HAM56 positive) and extracellular lipid, as well as at sites of foam cell formation. MCs and diffuse tryptase staining were also evident within sites of new calcification and around small calcified deposits. Extensive MC activation/degranulation, as judged by diffuse extracellular tryptase staining, was a common feature of the advanced atherosclerotic plaques complicated by fissure, haemorrhage, and thrombus formation. Moreover, such sites of extracellular MC tryptase were often associated with localized oedema and disruption of the stromal matrix. MCs which contained both tryptase and chymase (the MCTC phenotype) represented approximately 80-95 per cent of all MCs. These studies are the first to demonstrate significant numbers and focal accumulations of MCs in all developmental stages of atherosclerotic carotid arteries. Since MCs contain or express a variety of potent mediators, their release could profoundly influence the development and pathological complications of atherosclerotic plaques.

Eosinophilic vasculitis in connective tissue disease

Background: Neutrophilic and lymphocytic vascular inflammation is common in vasculitis associated with connective tissue disease (CTD). We recently identified eight patients with CTD and eosinophilic vasculitis. Objective: The purpose of this study was to characterize a variant form of vasculitis in CTD with eosinophilic infiltration. Methods: Of 98 CTD patients with cutaneous necrotizing vasculitis, eight were found with predominantly eosinophilic vascular infiltration. Nine CTD patients with cutaneous neutrophilic vasculitis were identified for comparison. Clinical and laboratory findings were reviewed and compared. Indirect immunofluorescence for eosinophil granule major basic protein (MBP), neutrophil elastase, and mast cell tryptase was performed on lesional tissue. MBP levels and eosinophil survival enhancing activity were assayed in sera from three patients. Results: The patients with eosinophilic vasculitis had depressed serum complement levels and peripheral blood eosinophilia; MBP levels were elevated in serum and eosinophil survival was prolonged. Immunofluorescence of tissue showed marked angiocentric eosinophil MBP staining with peripheral neutrophil elastase staining; mast cell tryptase staining was notably absent. The patients with neutrophilic vasculitis were variably hypocomplementemic and did not have peripheral blood eosinophilia. Immunofluorescence showed marked angiocentric neutrophil elastase staining with scattered eosinophil MBP staining; mast cell tryptase staining showed normal mast cell numbers. Conclusion: Patients with eosinophilic vasculitis, CTD, and hypocomplementemia show vessel wall destruction in association with vessel wall deposition of cytotoxic eosinophil granule MBP, which suggests that eosinophils mediate vascular damage in this disease process. In addition, perivascular mast cells appear diminished, therby suggesting that mast cell degranulation occurs.