Peripheral Nerve Sheath Tumors in Patients With Neurofibromatosis Type 1: Morphological and Immunohistochemical Study.

BACKGROUND/AIM: The aim of the present investigation was to characterize the growth pattern and antigen profile of peripheral nerve sheath tumors (PNST) in a large series of tumors obtained from patients with Neurofibromatosis type 1 (NF1) focusing on morphological characteristics of diffuse plexiform neurofibroma (DPNF). MATERIALS AND METHODS: Tissue micro-array (TMA) analysis was applied to study 520 formalin-fixed, paraffin-embedded human PNST of 385 patients with confirmed NF1 diagnosis. PNST originated from all areas of the body and were classified as cutaneous neurofibroma (CNF, n=114), diffuse neurofibroma (DNF, n=109), DPNF (n=108), plexiform neurofibroma (PNF, n=110), and malignant peripheral nerve sheath tumor (MPNST, n=22). Histomorphology and antigen expression patterns of the tumors were determined [S100, epithelial membrane antigen (EMA), CD90, mast cell tryptase, and neurofilament]. RESULTS: Benign PNST showed significantly more S100-positive tumor cells than MPNST (p<0.001). EMA expression was most pronounced in perineurium of DPNF. The number of mast cells in CNF, DNF and DPNF was significantly higher compared to PNF and MPNST (p<0.001 for both comparisons, Mann-Whitney U-test). CONCLUSION: DPNF show some distinct cellular characteristics. A high number of EMA positive cells possibly indicates the dissemination of perineural cells to the surrounding tissue. Concerning mast cell density, DPNF resemble DNF and CNS rather than PNF. Close contact of tumor cells in DPNF, DNF and CNF with the immune system is a prerequisite for permanent immunological reactions in contrast to PNF in which tumor cells are partitioned from the immune system by the perineurium and blood-nerve barrier of blood vessels. It is assumed that these morphological distinctions may reflect in part the biological differences between the entities. While PNF is a known precancerous stage in NF1 patients, DPNF are not rated as such. Furthermore, the morphologic differences between benign nerve sheath tumors may be important for the efficacy of drugs to access tumor cells.

Mimics of Allergy and Angioedema: Scombroid, Mast Cell Activation Disorders, and Hereditary Alpha Tryptasemia.

Scombroid poisoning, systemic mastocytosis, and hereditary alpha tryptasemia all present with episodes that resemble allergic reactions. Knowledge regarding systemic mastocytosis and hereditary alpha tryptasemia is quickly evolving. Epidemiology, pathophysiology, and strategies to identify and diagnose are discussed. Evidence-based management in the emergency setting and beyond is also explored and summarized. Key differences are described between these events and allergic reactions.

Comparative study between conventional and new methods in defining the cause of death from anaphylactic shock.

ABSTRACT: Anaphylaxis is defined as a rapid systemic reaction that develops in individuals previously exposed to specific allergens. The new exposure causes systemic cellular degranulation, which in turn leads to cardiovascular and respiratory changes that are fatal if not treated immediately. One of the main problems of this scenario in the forensic field is the determination of a correct post-mortem diagnosis. Traditional methods, such as histopathological examination of the respiratory tract and the use of specific antibodies used in immunohistochemistry, are sensitive but not always specific and therefore do not guarantee a high degree of probability in the diagnosis of anaphylaxis. For this reason, a new and promising research frontier in this field of forensic pathology could be represented by the application of miRNAs as biomarkers, as has been done in other areas of medicine.

Does Sugammadex Suppress Allergic Inflammation Due to Rocuronium in Animal Model of Rat?

INTRODUCTION AND OBJECTIVES: There are a few reports in the literature about the successful use of sugammadex in the treatment of hypersensitivity reactions caused by rocuronium; however, the pathophysiological mechanism is still unknown. This study aims to investigate the changes caused by rocuronium in the lung and the effect of sugammadex on these changes with biochemical, light microscopic and immunohistochemical parameters on a rat model. MATERIALS AND METHODS: For the study, 28-male Sprague-Dawley rats were randomly divided, seven of each, into four groups. Group C (control) received only 0. 9 % NaCl without any drug. Group R received rocuronium alone 1mg/kg. Group S received sugammadex alone 96 mg/kg. Group RS received rocuronium 1mg/kg and sugammadex 96 mg/kg. After 24 h later, the animals were sacrificed and their tissues were removed. Biochemical (IgE/CRP), light microscopic and immunohistochemical findings were recorded. RESULTS: Immunoglobulin E and CRP levels, peribronchial, alveolar septal lymphocytic infiltration, thickening of the alveolar membranes and bleeding sites in Group R were significantly higher than all the other groups. In Group RS, while these parameters were significantly lower than that of Group R and Group S, it was significantly higher than that of Group C. Total mast cells and tryptase-positive mast cells counts were significantly higher in Group R than in all other groups. In Group RS, these parameters were statistically lower than that of Group R and Group S, but higher than that of Group C. CONCLUSIONS: This study shows that allergic inflammatory changes due to rocuronium in the lungs of rats are reduced with sugammadex. These results support cases of anaphylaxis due to rocuronium which improved with sugammadex.

Tumor Cell Microenvironment and Microvessel Density Analysis in MALT Type Lymphoma.

BACKGROUND/AIM: MALT type lymphoma belongs to marginal zone lymphoma (MZL). MALT lymphomas' inflammatory microenvironment contributes to the pathogenesis of this cancer. In this study, we analyzed and quantified the tumor inflammatory microenvironment in MALT lymphoma samples and in healthy controls, and the microvessel content by immunohistochemistry and morphometric estimation. PATIENTS AND METHODS: Biopsy specimens from MALT type lymphoma patients and from non-metastatic axillary lymph nodes (CTRL) were analyzed by immunochemistry in order to quantify CD3, CD4, CD8, CD68, CD163, tryptase, CD34, and Ki67 positive cells. RESULTS: A substantial increase in the number of cells that were positive for the above markers and microvascular density (MVD) were observed in the MALT group. We also found a positive correlation between microvessels and CD8+ cells and between CD8+ cells and M2 type macrophages, while tryptase+ mast cells correlated with CD4+ cells. The mitotic proliferation index Ki67 was higher in MALT samples. CONCLUSION: The interactions between inflammatory cells in the tumor microenvironment and their correlation with angiogenesis is a useful tool in the development of new immunotherapy strategies.

Measurement of Tryptase and CC16/Albumin in Nasal Lavage Fluid as a Screening Tool of Allergic Rhinitis.

BACKGROUND: There is no trial to make a diagnostic tool of allergic rhinitis (AR) utilizing biomarkers from nasal fluid. Base on previous studies, we selected following five biomarkers in nasal fluids that represent the characteristics of allergic reactions: tryptase, eosinophil cationic protein (ECP), interleukin 5 (IL-5), Clara cell protein 16 (CC16) and CC16-to-albumin ratio. OBJECTIVE: This study aimed to identify biomarkers in nasal discharge that may be used in biosensors to diagnose AR as an additional diagnostic tool. METHODS: Patients showed rhinorrhea and tested positive on allergic skin and specific immunoglobulin E (IgE) tests were included in the AR group. The non-AR group included individuals no dominant nasal symptoms and tested negative on allergy tests. Nasal lavage fluid samples were collected from all participants. Biomarkers in the samples were quantified using enzyme-linked immunosorbent assay. RESULTS: Forty-five patients with AR and 28 non-AR subjects were enrolled in this study. Comparing the concentrations of biomarkers, the concentrations of tryptase and IL-5 were significantly higher in the AR group than in the NAR group. And CC16 level and CC16-to-albumin ratio were significantly lower in the AR group. In the combination of tryptase or CC16-to-albumin ratio, the sensitivity was 90.7% and the specificity was 64.3% (p = 0.013). CONCLUSION: The combination of "tryptase or CC16-to-albumin" could be used as a screening tool for AR. Although this diagnostic method could not replace conventional diagnostic tools, we could consider the method we proposed as an additional screening tool for patients who could not undergo allergy tests.

Identification of Murine Basophils by Flow Cytometry and Histology.

Here, we describe how murine basophils can be detected in vivo by flow cytometry and immunofluorescence staining. Basophils constitute a homogeneous population of CD4-CD19-CD49b+IgE+ cells in flow cytometric analysis. When IgE levels are low, one can also use anti-FcεRI or anti-CD200R3 antibodies instead of anti-IgE. For immunofluorescence staining, we use an anti-Mcpt8 antibody since Mcpt8 is a specific marker for murine basophils. We describe how to prepare the tissue to cut cryo-sections and how to perform the staining using a tyramide-based amplification kit.

[Tryptase: A practical guide for the physician]. / Dosage de la tryptase : un guide d'utilisation pour le clinicien.

Tryptase is the most abundant endopeptidase released by mast cells degranulation, involved in many pro and anti-inflammatory processes. Normal serum tryptase range is 0-11.4 µg/L. Tryptase is a useful diagnostic tool for anaphylaxis, systemic mastocytosis (SM) and mast cell activation syndrome (MCAS), where specific threshold values must be used. SM diagnosis criteria include evidence of dense mast cell infiltrate either in the bone marrow or the affected organ (such as skin), presence of KIT D816V mutation and elevated serum tryptase level (>20 µg/L). In SM, tryptase level is correlated with the burden of mast cells in bone marrow. MCAS should be considered in case of severe and recurrent typical clinical signs of systemic mast cell activation involving at least two organs, associated with an increase in serum tryptase level of 20% + 2 µg/L from the individual's baseline. Anaphylaxis is the most severe among hypersensitivity reactions. A clonal mast cell disorder is a central question in anaphylaxis and appropriate explorations should be conducted in these patients. Triggers for anaphylactic reactions vary significantly in the general population and in patients with MS or MCAS. Finally, physicians must be aware of the many pathological and physiological situations that affect tryptase levels.

[Performance criteria for the verification of IgE and tryptase assay methods: recommendations from the AllergoBioNet network]. / Critères de performance pour la vérification des méthodes de dosages des IgE et de la tryptase : recommandations du réseau AllergoBioNet.

Accreditation of an in vitro diagnostic assay according to the NF/EN/ISO 15189 standard requires to analyze its technical performance before implementation for routine use, and annually when reviewing effectiveness of quality controls. Performance is evaluated through repeatability, intermediate fidelity, accuracy and uncertainty of measurement. The coefficients of variation (CV) of the intra-assay and inter-assay precision tests must be compared with those of "peers" (results from laboratories employing the same method) and also with those obtained with "all methods", i.e., results from all laboratories performing the same assay, irrespective of the method. To our best knowledge, there is currently no French or international recommendation on what the acceptable limits of performance for specific IgE and tryptase assays should be. Therefore, the AllergoBioNet network of hospital allergy laboratories set out to characterize the performance of their current methods as a basis for the development of recommendations. The results provided by 24 centers were analyzed and led to consensus recommendations for specific IgE, total IgE and tryptase assays.

Liquid Chromatography Tandem Mass Spectrometry Based Label-Free Quantification Method for Assessment of Allergen-Induced Anaphylactoid Reactions.

Mast cells are essential in mediating inflammatory processes. When activated, mast cells can rapidly release characteristic granules and various mediators into the interstitium. Tryptase (TPS) and ß-hexosaminidase (HEXB) are typical protease mediators stored in granules and released upon activation. They have been recognized as important biomarkers of anaphylaxis, and the released level is associated with the severity of allergic reactions. In this study, a sensitive, accurate, and selective liquid chromatography tandem mass spectrometry (LC-MS/MS) method for simultaneously quantifying the two biomarkers was developed and validated in LAD2 cell culture supernatant, and P14R was used as internal standard. Good linearity was observed in the range of 50-2500 ng/mL for TPS and 10-2000 ng/mL for HEXB both with R2 > 0.99. The matrix effect and recovery were both within acceptable limits. We quantified TPS and HEXB released from Laboratory of Allergic Disease 2 (LAD2) mast cells treated with several potential allergens, and the results demonstrate that the method can be used to investigate TPS and HEXB levels in LAD2 mast cell model during allergy research. We anticipate our approach to be a robust and sensitive assessment method for more biomarkers with similar kinetics characteristics and to be a major tool of allergic drug assessment or antiallergic drug development in research.

High Extratumoral Mast Cell Counts Are Associated with a Higher Risk of Adverse Prostate Cancer Outcomes.

BACKGROUND: Given our previous findings that low intratumoral and high extratumoral mast cell numbers are associated with higher risk of biochemical recurrence after radical prostatectomy, we now assessed this relationship with race and the development of metastases. METHODS: We stained for mast cell tryptase via IHC and fluorescent immunolabeling in 885 men across multiple tissue microarray sets designed to assess biomarkers in association with race and prostate cancer outcomes (median follow-up, 7.0 years). RESULTS: Intratumoral and extratumoral mast cell counts were significantly lower in tissues from African-American compared with European-American men, but not within strata of cancer grade. There was no association between mast cell counts and ERG positivity, PTEN loss, or TP53 missense mutation. Higher minimum extratumoral mast cells were associated with an increased risk of biochemical recurrence [comparing highest with lowest tertiles: HR, 1.61; 95% confidence interval (CI), 1.12-2.29; P trend = 0.01]; this pattern was similar among European-American and African-American men and by grade of disease. There was no significant association between minimum intratumoral mast cell count and biochemical recurrence, overall or within strata of race and grade. Finally, high minimum number of extratumoral mast cells was associated with prostate cancer metastases (comparing highest with lowest tertiles: HR, 2.12; 95% CI, 1.24-3.63; P trend = 0.01). CONCLUSIONS: High extratumoral mast cell numbers are associated with biochemical recurrence and the development of metastases after radical prostatectomy. IMPACT: Higher numbers of benign tissue mast cells are associated with a higher risk of adverse outcomes after radical prostatectomy, including metastatic prostate cancer.

Development of an effective sample transfer device for biomarker detection in nasal secretions.

Nasal secretions (NS) reflect inflammatory activity of the nasal mucosa and thus can be utilized for disease diagnosis and determining treatment effects in Allergic rhinitis (AR). However, non-standardized collection of samples can affect the measured concentration of inflammatory biomarker in NS. In this study, we aimed to develop and evaluate new devices capable of standardizing the collection, storage, and preprocessing methods of NS samples. First, we chose the best swab as polyester (PE) and selected a stimulation method, twirling for 10 s at 1 Hz, to efficiently release AR biomarkers from a PE swab. Storage of sample solutions at -20 °C was optimal for the stability of biomarkers for the detection of AR. The new swab sample transfer device showed excellent concentration recovery efficiency (90-100%) for tryptase (Trp) and eosinophil cationic protein (ECP) without crosstalk between the two biomarkers. Finally, we compared the concentration of Trp in human NS samples of AR patients (n = 6) pre-processed by the new device with that by centrifuge as a standard method. As a result, the concentrations of Trp in NS were very similar in both groups. Therefore, this device can be utilized as an effective sample transfer and pre-processing device for point-of-care testing of AR.

Riesgo anafiláctico por mastocitosis sistémica: manejo perioperatorio en cirugía cardíaca / Anaphylactic risk due to systemic mastocytosis: perioperative management in cardiac surgery

La mastocitosis es una enfermedad caracterizada por una proliferación anormal de los mastocitos. La degranulación de los mastocitos puede desencadenarse por factores químicos, físicos y psíquicos, y en casos graves puede cursar con alteraciones cardiovasculares y shock. Concentraciones de triptasa superiores a 20mcg/l se podrían correlacionar con mayor riesgo de degranulación mastocitaria. Presentamos el caso de un varón de 71 años sometido a cirugía de sustitución valvular aórtica y derivación aortocoronaria con mastocitosis sistémica indolente, con antecedentes de crisis histaminérgicas y con valores basales previos a la cirugía de tripatasa de 58,1mcg/l

Mastocytosis is a disease characterised by an abnormal proliferation of mast cells. The degranulation of mast cells can be triggered by chemical, physical, and psychological factors, and in severe cases may be accompanied by cardiovascular alterations and shock. Tryptase concentrations greater than 20ug/L may be associated with an increased risk of mastocyte degranulation. The case is presented on a 71 year-old man that underwent an aortic valve replacement and aortic-coronary bypass surgery. He had an indolent systemic mastocytosis and a history of histaminergic crises, with a baseline value of tryptase prior to surgery of 58.1ug/L

Menos es más / Not many is the good, but in the good, the many

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An ultrasensitive electrochemical detection of tryptase using 3D macroporous reduced graphene oxide nanocomposites by one-pot electrochemical synthesis.

In this study, we introduce an ultrasensitive and stable sensing platform based on gold nanoparticle decorated 3D reduced graphene oxide - carbon nanotube nanocomposites (GNP/CNT/rGO) for detection of tryptase (Tryp), which is a potential biomarker within nasal secretions for allergic rhinitis (AR). The GNP/CNT/rGO on the glassy carbon electrode (GCE) was fabricated through single-step one-pot electrochemical co-reduction and deposition. The GNP/CNT/rGO exhibited excellent electrocatalytic activity as the working electrode compared with bare GCE, GNP/rGO and CNT/rGO on GCEs. The enhanced performance of GNP/CNT/rGO may be attributed to 3D macroporous structures, which may provide increased surface area, faster charge transfer and lower mass transport resistance, as well as high electrocatalytic activity and good biocompatibility due to GNP. A GNP/CNT/rGO-based sandwich-type electrochemical immunosensor was fabricated for detection of Tryp, which requires high sensitivity and specificity. The GNP/CNT/rGO-based immunosensor exhibited a detection range from 100 pg/mL to 100 ng/mL, a detection limit of 50 pg/mL and a sensitivity of 1.64 µA/(ng/mL). This immunosensor possessed high selectivity, excellent reproducibility (RSD 2.1%) and high stability over approximately 1 month. Therefore, we expect that the GNP/CNT/rGO and the modified immunosensor will be useful tools for detecting Tryp in nasal secretions for clinical diagnosis of AR.

Frequency of isolated cutaneous involvement in adult mastocytosis: a cohort study.

BACKGROUND: Mastocytosis is characterized by the accumulation/proliferation of abnormal mast cells. The frequency of isolated cutaneous involvement in adults with mastocytosis has not been fully determined. The main objective of our study was to assess the frequency of isolated cutaneous mastocytosis (CM) in adults with mastocytosis skin lesions. The second objective was to compare the clinical, histological, biological and imaging features in patients with isolated CM and patients with systemic mastocytosis (SM). METHODS: We included all patients with histology-proven mastocytosis skin lesions between January 2009 and December 2017. The mastocytosis diagnosis was made according to the international diagnostic criteria. All data were collected from a dedicated specific case report. RESULTS: Among 160 patients with mastocytosis skin lesions, 25 patients had isolated CM (15.6%), 105 had SM and 30 (18.7%) patients had undetermined mastocytosis. Skin KIT mutation (OR: 51.9, 95% CI: 3.9-678, P = 0.001) and high bone marrow tryptase (OR: 97.4, 95% CI: 10.3-915, P = 0.001) were strong predictors of SM. The prevalence of osteoporosis was higher in the SM population than in the isolated CM population. Moreover, a decrease in bone mineral density over a short period of follow-up (1-2 years) was associated with SM. There were no differences between the two groups regarding the frequency of mast cell activation symptoms, the presentation of skin lesions, the number of mast cells in the dermis and the level of serum tryptase. We propose considering the KIT mutation status and bone marrow tryptase levels to aid the diagnosis of isolated CM in adult mastocytosis patients. CONCLUSION: Only a small minority of adults with mastocytosis skin lesions has isolated cutaneous involvement. In 18.7% of mastocytosis cases, even complete workup does not allow for a precise classification of patients.

Searching for tryptase in the RBL-2H3 mast cell model: Preparation for comparative mast cell toxicology studies with zebrafish.

Mast cells comprise a physiologically and toxicologically important cell type that is ubiquitous among species and tissues. Mast cells undergo degranulation, in which characteristic intracellular granules fuse with the plasma membrane and release many bioactive substances, such as enzymes ß-hexosaminidase and tryptase. Activity of mast cells in the toxicology model organism, zebrafish, has been monitored via tryptase release and cleavage of substrate N-α-benzoyl-dl-Arg-p-nitroanilide (BAPNA). An extensively used in vitro mast cell model for studying toxicant mechanisms is the RBL-2H3 cell line. However, instead of tryptase, granule contents such as ß-hexosaminidase have usually been employed as RBL-2H3 degranulation markers. To align RBL-2H3 cell toxicological studies to in vivo mast cell studies using zebrafish, we aimed to develop an RBL-2H3 tryptase assay. Unexpectedly, we discovered that tryptase release from RBL-2H3 cells is not detectable, using BAPNA substrate, despite optimized assay that can detect as little as 1 ng tryptase. Additional studies performed with another substrate, tosyl-Gly-Pro-Lys-pNA, and with an enzyme-linked immunosorbent assay, revealed a lack of tryptase protein released from stimulated RBL-2H3 cells. Furthermore, none of the eight rat tryptase genes (Tpsb2, Tpsab1, Tpsg1, Prss34, Gzmk, Gzma, Prss29, Prss41) is expressed in RBL-2H3 cells, even though all are found in RBL-2H3 genomic DNA and even though ß-hexosaminidase mRNA is constitutively expressed. Therefore, mast cell researchers should utilize ß-hexosaminidase or another reliable marker for RBL-2H3 degranulation studies, not tryptase. Comparative toxicity testing in RBL-2H3 cells in vitro and in zebrafish mast cells in vivo will require use of a degranulation reporter different from tryptase.

Basal Tryptase Levels Can Predict Clinical Severity in Hymenoptera Venom Anaphylaxis and Ischemic Cardiovascular Disorders

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Síndrome coronario agudo y anafilaxia / Acute coronary syndrome and anafilaxia

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