Number Of Tryptase-positive Mast Cells Research Articles

Mast cell infiltration is a favourable prognostic factor in diffuse large B‐cell lymphoma

Previous studies indicate that the inflammatory response in diffuse large B-cell lymphomas (DLBCL) is important for the clinical outcome. Mast cells are key regulators in this response; we investigated whether the number of tryptase-positive mast cells is correlated with clinical outcome. Patients with many mast cells had a significantly better event-free survival (EFS) compared to those with few mast cells (P < 0.03 in both germinal centre (GC) and non-GC DLBCL. This supports the idea that the infiltration of mast cells is a reflection of the host inflammatory response and is related to a favourable outcome.

Urticarial vasculitis appearing in the progression of systemic sclerosis

We report a case of urticarial vasculitis that appeared during the course of limited cutaneous systemic sclerosis. The urticarial lesions responded to systemic administration of prednisolone. After the appearance of urticarial vasculitis, the progression of scleroderma in distal sites of her elbow and knee joint became apparent. We consider this case to be consistent with limited cutaneous systemic sclerosis. The patient started treatment with prednisolone and her edema as well as scleroderma softened gradually. We analyzed, by immunohistochemistry, the number of tryptase-positive mast cells of this case in the lesions of urticarial vasculitis as well as systemic sclerosis. The number of tryptase-positive mast cells in the lesions of urticarial vasculitis as well as systemic sclerosis was significantly increased compared to normal skin (P < 0.05 and P < 0.005, respectively). We demonstrate that, in the present case, mast cells might be involved in both courses of urticarial vasculitis and systemic sclerosis as a common factor.

Mast Cells in the Diffuse Large B-Cell Lymphoma; Their Role for Fibrosis.

Mast cells (MCs) play an important role in tissue remodeling in inflammation. According to content of tryptase and chymase, MC is divided into two phenotypes; MCTC phenotype contains tryptase and chymase, while MCT phenotype contains only tryptase. Recent studies have revealed that interleukin-4 (IL-4) promotes the maturation of MCs and the development of MCTC phenotype from MCT phenotype. Although MCs infiltration into diffuse large B-cell lymphoma (DLBCL) has been reported, MC phenotypes infiltrating into lymphomas remain unknown. We examined MC phenotype infiltrating into lymph nodes in 50 DLBCL and 20 reactive lymph nodes, and evaluated their association with fibrosis. We also evaluated IL-4-expressing cells in DLBCL. Reviewing hematoxylin-eosin stain and Azan-Mallory stain, 50 cases with DLBCL were divided into 3 groups; no fibrosis type in 32, reticular type in 8, showing fine reticular fibrosis in focal areas, and bundle type in 10, showing thick collagenous bundle through the parenchyma. Using these formalin-fixed and paraffin-embedded specimens, immunohistochemistry for tryptase and chymase was performed. Furthermore, immunodouble staining methods were performed to detect the MC phenotypes and the cells that express IL-4 in DLBCL, using frozen sections. Tryptase-positive, and chymase-positive MCs were found in all groups of DLBCL and density of tryptase-positive MCs were higher than that of chymase-positive MCs. Densities of trytase-positive, and chymase-positive MCs in fibrotic areas were significantly higher than those in the areas without fibrosis (reticular type; 12.681 ± 11.307 / mm2 vs. 2.082 ± 2.260 / mm2, p = 0.018, bundle type; 22.407 ± 11.989 / mm2 vs. 1.319 ± 1.937 /mm2, p = 0.005, in tryptase-positive MCs, reticular type; 4.758 ± 5.468 / mm2 vs. 0.440 ± 1.164 / mm2, p = 0.028, bundle type; 4.114 ± 5.216 / mm2 vs. 0.220 ± 0.374 / mm2, p = 0.008; in chymase-positive MCs). Numbers of tryptase-positive MCs in reactive lymph nodes were not different from those in no fibrosis type of DLBCL. There were few chymase-positive MCs in reactive lymph nodes. Immunodouble staining revealed that MCs in DLBCL comprised MCT and MCTC phenotypes. Chymase-positive MCs and T-lymphocytes expressed IL-4. These findings suggest that T-lymphcytes play a role in the development of MCTC phenotype from MCT phenotype in DLBCL and that tryptase-positive MCs and chymase-positive MCs are associated with the development of fibrosis in DLBCL.

Retinoic Acid Inhibits in vitro Development of Mast Cells But Has No Marked Effect on Mature Human Skin Tryptase- and Chymase-Positive Mast Cells

Stem cell factor plays a key role in the development of human mast cells via interaction with Kit receptor. We and other groups have previously shown that a number of cytokines can regulate the stem-cell-factor-dependent development of mast cells in vitro. In this study we investigated the effect of retinoic acid on human mast cells in vitro and in vivo. Retinoids are known to have strong modulatory effects on hematopoietic differentiation. We found that all-trans-retinoic acid, at concentrations as low as 1 nM, inhibits the stem-cell-factor-dependent differentiation of mast cells in vitro. This effect of retinoic acid was found to be on progenitor cells, whereas more mature mast cells were less affected. The use of specific agonists binding either to the RAR or the RXR nuclear receptors indicated involvement of both the RAR/RXR and RXR/RXR pathways in inhibiting mast cell differentiation. In contrast to the effects on mast cell progenitors, retinoic acid had no effect on the number of mature mast cells in skin organ cultures. Furthermore, topical treatment of normal skin with a retinoic-acid-containing cream caused an increase in the number of tryptase-positive mast cells, whereas the numbers of the major cutaneous mast cell type, tryptase- and chymase-positive mast cells, remained unaffected. Our results suggest that retinoic acid suppresses commitment of progenitor cells into the mast cell lineage and/or acts on early mast cell progenitors, whereas mature cutaneous mast cells are less susceptible to retinoic acid.

TH1/TH2 cytokines and inflammatory cells in skin biopsy specimens from patients with chronic idiopathic urticaria: Comparison with the allergen-induced late-phase cutaneous reaction

Background: Previous studies have demonstrated infiltration of eosinophils, neutrophils, monocytes, and T cells in the skin of patients with chronic idiopathic urticaria (CIU), suggesting a possible TH2-type cytokine pathology analogous to the allergen-induced skin late-phase reaction (LPR). Objective: We sought to compare skin biopsy specimens from patients with CIU and the allergen-induced skin LPR for mRNA+ cells for IL-4, IL-5, and IFN-γ and inflammatory cell infiltration. Methods: Skin biopsy specimens were obtained from 13 patients with CIU (6 had positive results for FcϵRI autoantibodies), 6 nonatopic control subjects, and 6 atopic subjects (before and after cutaneous allergen challenge). Cryostat sections were processed for immunohistochemistry and in situ hybridization by using the 35S-riboprobes. Results: There were significant increases in the numbers of intradermal CD3+ (P = .007), CD4+ (P = .004), CD8+ (P = .012), and CD25+ (P = .018) T cells, as well as eosinophils (P = .02), neutrophils (P = .01), basophils (P = .004), and macro-phages (P = .0014) in patients with CIU compared with numbers in nonatopic control subjects. There were lower numbers of tryptase-positive mast cells (P = .048). In the epidermis of patients with CIU, but not in that of normal subjects or in allergen-challenged biopsy specimens, there were increased numbers of CD3+ T cells (P = .039). The profile of inflammatory cell infiltration in the allergen-induced skin LPR was similar to that in patients with CIU. In patients with CIU there was a TH0 cytokine profile, with significant increases in IL-4 (P = .0029), IL-5 (P = .0025), and IFN-γ (P = .037) mRNA+ cells. As expected, in the skin LPR there was an increase in IL-4 (P = .0082) and IL-5 (P = .0051), but not IFN-γ, mRNA+ cells. There were no significant differences in either the numbers of inflammatory cells or the cytokine pattern between patients with and without autoantibody. Conclusion: The molecular immunopathology of CIU is that of an eosinophil and basophil cell-mediated hypersensitivity reaction. Thus it is similar to the allergic skin LPR but has a TH0 rather than a TH2 cytokine profile. (J Allergy Clin Immunol 2002;109:694-700.)

Structural examination of tryptase-, and VIP-positive mast cells in the common bile duct of patients with lithiasis

The morphology of tryptase-, and vasoactive intestinal polypeptide (VIP)-positive mast cells was examined immunohistochemically in 38 common bile ducts collected from patients with secondary chronic cholangitis and varying degrees of inflammatory activity. Mast cells numbers in chronic exacerbated and chronic sclerotic cholangitis were significantly higher as compared with those in controls (72.4 cells/mm2 and 25.2 cells/mm2 vs. 5.9 cells/mm2; p < 0.0001, Student's t test). The increased number of tryptase-positive mast cells in chronic exacerbated cholangitis correlated with the severeness of inflammatory infiltration. In cases of chronic exacerbated cholangitis, the increased number of mast cells was detected in conjunction with active fibroplasia. In chronic sclerotic cholangitis mast cells were lower in number as compared with exacerbated cholangitis and were observed in relation with inactive fibrosis. Numerous VIP-positive mast cells were found in all patients with cholangitis. Ultrastructural immunocytochemistry showed tryptase positivity to be localized over either electron-dense or particulate granules with a mean diameter of 0.261+/-0.073 microm or 0.171+/-0.053 microm, respectively. VIP positivity was formed as a finely or coarsely granular pattern over larger electron-dense granules of 0.475+/-0.14 microm in diameter. Tryptase-positive mast cells were located mainly in and around surface and glandular epithelium. The involvement of tryptase- and VIP-positive mast cells in inflammation, fibrosis and epithelial reactions in the common bile duct is discussed.

Neuronal hypertrophy in acute appendicitis.

The pathogenesis of appendicitis remains poorly understood. However, there is increasing evidence of involvement of the enteric nervous system in immune regulation and in inflammatory responses. This study was set up to characterize the status of the enteric nervous system in normal and in inflamed appendixes. S100- and 2',2'-cyclic nucleotide 3' phosphodiesterase-positive Schwann cells, synaptophysin, and neuron-specific, enolase-positive nerve fibers and tryptase-positive mast cells were evaluated with immunohistochemical staining in surgically resected appendixes from 20 children with histologically proven acute appendicitis (HA), 10 histologically normal appendixes (HN) from patients with a clinical diagnosis of appendicitis, and 10 normal appendixes from patients undergoing elective abdominal surgery. Immunostained sections were subjected to quantitative image analysis. The number and size of ganglia and the number of nerve fibers, Schwann cells, and mast cells in each tissue compartment was quantitatively or semiquantitatively measured. Increased numbers of fibers, Schwann cells, and enlarged ganglia, widely distributed in the muscularis externa and submucosa, were seen in all HA appendixes and in 4 of 10 HN appendixes. The number and size of ganglia in muscularis externa and in the submucosa of appendixes with HA were significantly greater compared with those in control appendixes (P <.001). A significantly increased number of individually stained nerve fibers and Schwann cells (P <.05) were present in the muscularis externa in HA appendixes compared with control appendixes. Significantly increased numbers of tryptase-positive mast cells (P <.05) were present in the submucosa, muscularis, and especially in the lamina propria in HA specimens, compared with that of control tissue. The significant increase in neural components and mast cells in acute appendicitis is unlikely to develop during a single acute inflammatory episode. This suggests an underlying chronic abnormality as a secondary reaction to repeated bouts of inflammation, obstruction, or both. These results challenge our current understanding of the pathophysiological processes that give rise to acute appendicitis.

Release of histamine and leukotriene C4 in immediate allergic wheal reaction as measured with the microdialysis technique.

Other mediators as well as histamine can contribute to the allergic wheal reaction. In this study, the microdialysis technique was used to monitor the release of histamine, leukotriene C4 (LTC4) and prostaglandin D2 (PGD2) in prick-test wheal reactions induced by cow dander allergen. Of 31 atopic subjects, 25 showed detectable histamine release that correlated significantly with the number of tryptase-positive mast cells and serum cow-specific IgE but not with the wheal size. Detectable LTC4 release was shown by 16 of 18 subjects, but PGD2 release was shown by only 7 of 17 subjects, and neither mediator was associated with tryptase-positive mast cells, IgE levels or wheal size. An inverse association between histamine release and LTC4 release in these 18 subjects was found rather than a direct correlation. With advancing age of the subject histamine release (n = 31) tended to decrease, although insignificantly, but LTC4 release (n = 18) and sensitivity to histamine prick increased significantly, which seemed to parallel the changes in the wheal size induced by cow allergen. In conclusion, the results showed that the release of histamine, LTC4 or PGD2 alone cannot explain the extent of the wheal reaction. In addition, the amount of histamine released was not related to the amount of LTC4 released, but rather an inverse association existed between these mediators.

Atopic dermatitis: from the genes to skin lesions.

Atopic dermatitis: from the genes to skin lesions.

Mast cells and their mediators in cutaneous wound healing--active participants or innocent bystanders?

Mast cells are traditionally viewed as effector cells of immediate type hypersensitivity reactions. There is, however, a growing body of evidence that the cells might play an important role in the maintenance of tissue homeostasis and repair. We here present our own data and those from the literature elucidating the possible role of mast cells during wound healing. Studies on the fate of mast cells in scars of varying ages suggest that these cells degranulate during wounding, with a marked decrease of chymase-positive cells, although the total number of cells does not decrease, based on SCF-receptor staining. Mast cells contain a plethora of preformed mediators like heparin, histamine, tryptase, chymase, VEGF and TNF-alpha which, on release during the initial stages of wound healing, affect bleeding and subsequent coagulation and acute inflammation. Various additional vasoactive and chemotactic, rapidly generated mediators (C3a, C5a, LTB4, LTC4, PAF) will contribute to these processes, whereas mast cell-derived proinflammatory and growth promoting peptide mediators (VEGF, FGF-2, PDGF, TGF-beta, NGF, IL-4, IL-8) contribute to neoangiogenesis, fibrinogenesis or re-epithelization during the repair process. The increasing number of tryptase-positive mast cells in older scars suggest that these cells continue to be exposed to specific chemotactic, growth- and differentiation-promoting factors throughout the process of tissue remodelling. All these data indicate that mast cells contribute in a major way to wound healing. their role as potential initiators of or as contributors to this process, compared to other cell types, will however have to be further elucidated.

Mast cells are augmented in deep vein thrombosis and express a profibrinolytic phenotype

A number of recent data suggest that mast cells (MC) and their products are involved in the pathophysiology of thrombosis. In the current study, we have evaluated the number, distribution, and phenotype of MC in patients with deep vein thrombosis of the lower limb (DVT) ( n = 15). Contralateral nonthrombosed limb veins served as control (CO). MC were examined by Giemsa staining and by immunohistochemistry using antibodies against tryptase, chymase, tissue-type plasminogen activator (tPA), urokinase (uPA), urokinase receptor (uPAR), and plasminogen activator inhibitors (PAI-1, PAI-2). We found an increase in the number of tryptase-positive MC in DVT compared with CO (DVT: 9.1 ± 1.0 v CO: 4.7 ± 0.6 MC/mm 2, P < .05). Most of these MC appeared to accumulate in the adventitia of the thrombosed veins, in vicinity of the vasa vasorum. In both DVT and CO, MC reacted with monoclonal antibodies to c- kit, tryptase, and chymase. MC also stained positive for tPA and urokinase receptor, but did not express detectable PAI-1 or PAI-2. As compared with CO, a decreased proportion of MC in DVT was found to stain positive for chymase and tPA. Together, our results show that MC increase in number in DVT and express a profibrinolytic phenotype. We hypothesize that MC and MC-derived profibrinolytic molecules play a role in the pathophysiology of DVT.

Ivermectin influence on the mast cell activity in nodules of onchocerciasis patients.

Onchocercal nodules were stained immunohistochemically using antibodies specific for human mast cells and IgE to elucidate the localization and frequency of mast cells after a single oral dose of 150 microg/kg ivermectin. Tryptase-and chymase-positive mast cells occurred predominantly in mixed inflammatory infiltrates and perivascularly, and never adhered to adult worms or microfilariae. Up to three days after ivermectin, mast cells and IgE-positive cells were markedly increased in the capsular area of nodules containing female worms with embryos and microfilariae compared to untreated nodules. In the centre of these nodules, around the adult Onchocerca volvulus, we found many tryptase-positive cells. More mast cells were IgE-positive than in untreated nodules, equalling the number of tryptase-positive mast cells. There was a clear correlation between the appearance of mast cells and the attacks on damaged microfilariae by eosinophils and macrophages and in the vicinity of adult worms by neutrophils that occur soon after ivermectin treatment. Onchocercomata harbouring female worms with oocytes only revealed, after all treatment intervals, the same mast cell numbers as untreated nodules. In conclusion, during the first three days after administration, ivermectin produces increased numbers of mast cells in nodules harbouring females with embryos and microfilariae, probably as part of an allergic reaction to the attacked microfilariae. Four to 19 days after ivermectin the number of mast cells in the entire nodule is no longer elevated.

Psoriasis patients have highly increased numbers of tryptase-positive mast cells in the duodenal stroma

We have shown that the number of tryptase-positive mast cells in the duodenal mucosa in psoriasis is increased and that a subgroup of psoriasis patients showed elevated levels of antibodies to gliadin (some of whom also had increased lymphocytes in the duodenal epithelium). Duodenal biopsy specimens from 37 patients with psoriasis (eight mild, 13 moderate and 16 severe) and 22 patients with irritable bowel syndrome (IBS) were examined regarding the presence of tryptase + mast cells. Intraepithelial infiltration by lymphocytes was evaluated and scored from 0 to 3. Patients with psoriasis had 131 +/- 58 mast cells/mm2 (mean +/- SD) and those with IBS 28 +/- 18. Only in four of the 37 psoriasis patients was the number within the range of that in the IBS group. There were no signs of stromal inflammation except in one psoriasis patient. No relationship was found between degree of severity of psoriasis and number of mast cells. In 25 of the 37 specimens from psoriasis patients there was no increase in intraepithelial lymphocytes, whereas seven showed a slight increase (score 1-2) and five a moderate increase (score > or = 2-3). The number of tryptase + mast cells was similar in patients with or without increased intraepithelial lymphocytes. The number of mast cells showed no relation to the presence or absence of antibodies to gliadin. We hypothesize that there are at least two types of abnormalities in the duodenal mucosa in psoriasis, one type that is present in most psoriasis patients and characterized by an increase in mast cells and eosinophils, and another that is present in a subgroup of patients with antibodies to gliadin and an increased number of duodenal intraepithelial lymphocytes. The mechanisms underlying the increase in the number of mast cells and its relevance are not yet known.

Psoriasis patients have highly increased numbers of tryptase-positive mast cells in the duodenal stroma

Psoriasis patients have highly increased numbers of tryptase-positive mast cells in the duodenal stroma

Quantitative enzyme-histochemical analysis of tryptase- and chymase-containing mast cells in psoriatic skin

Tryptase-containing mast cells have recently been found to be increased in the upper dermis of psoriatic lesions. In the present study, the distribution of chymase- and tryptase-containing mast cells was morphometrically analysed at different dermal levels of lesional and non-lesional psoriatic skin (12 patients) as well as normal human skin. Mast cell tryptase was identified enzyme-histochemically, using Z-Gly-Pro-Arg-MNA as the substrate. For demonstrating mast cell chymase, a simple and specific enzyme-histochemical staining method was developed, using Suc-Val-Pro-Phe-MNA as the substrate. All mast cells positive for chymase were also positive for tryptase and Giemsa stain. Although the number of tryptase-positive mast cells was slightly increased throughout the dermis of lesional psoriatic skin, this increase was most pronounced in the upper dermis immediately beneath, and in close contact with, the epidermis. In contrast, the number of chymase-positive mast cells was clearly decreased in the upper dermis of psoriatic lesions, but not in the deeper dermis, as compared with non-lesional psoriatic skin. In addition, all chymase-positive mast cells observed in the upper dermis were very weakly stained when compared with those in the deeper dermis. No differences were found between non-lesional psoriatic skin and normal skin in which the number of mast cells containing chymase was 72-73% of the number containing tryptase. The present results suggest that T mast cells particularly, containing tryptase but no chymase, proliferate in psoriatic lesions, and that the increase in tryptase activity and the decrease in chymase activity in the upper dermis may lead to an imbalance in the biochemical regulatory systems.

Enzyme- and immunohistochemical localization of mast cell tryptase in psoriatic skin

The localization of mast cell tryptase in involved and noninvolved skin sections from 12 psoriatic patients was investigated using both enzyme- and immunohistochemical staining techniques. Each involved skin section contained an increased number of tryptase-positive mast cells in the superficial dermis as compared with corresponding noninvolved skin sections. The substrate-hydrolyzing and inhibition properties for tryptase activity in involved and non-involved psoriatic skin sections were identical with each other as well as with those previously described in normal human skin or mastocytoma skin sections. In four patients, epidermal enzyme activity was observed, but only in the involved skin. None of the uninvolved sections showed tryptase activity in the epidermis. This activity was not inhibited by alpha 1-antitrypsin, and after removing the enzyme-histochemical stain with Tween 20, positive results obtained with tryptase-specific antibody were found in the same locations. In addition, tryptase-positive cells were detected in close contact to lesional epidermis, but without epidermal staining in four patients. In the epidermis, the positive staining was granular, and active tryptase was detected as far as the stratum corneum. This study is the first description of the presence of active mast cell tryptase in psoriatic epidermis, where this enzyme may have a role in increased cell division.