Showing papers by "Per Venge published in 2002"

Clinical performance of three cardiac troponin assays in patients with unstable coronary artery disease (a FRISC II substudy).

Abstract: Clinical performance of three cardiac troponin assays in patients with unstable coronary artery disease (a FRISC II substudy).

Multicenter Evaluation of an Automated Assay for Troponin I

Abstract: Background: Cardiac troponin I (cTnI) is a powerful tool to aid in the diagnosis of myocardial infarction and cardiac muscle damage. We describe an assay that overcomes problems of early assays that were often affected by cTnI degradation, assay interference, poor sensitivity, and imprecision. Methods: The analytical performance of the Access® AccuTnITM assay (Beckman Coulter) was evaluated at five institutions. Controls, zero calibrator, and diluted patient samples were used to determine precision, detection limit, functional sensitivity, and linearity. The 97.5 and 99 percentiles of a reference population were determined. Common interferents and heterophilic patient samples were tested. Equimolarity was determined by assaying samples with various ratios of free and complexed cTnI. Matched samples drawn into serum, EDTA, lithium heparin, and sodium heparin sample tubes were compared. Results: Total imprecision (CVs) was 4.0–8.8% between 0.40 and 31 μg/L cTnI. The detection limit was 60 μg/L and not affected by common assay interferents. An equimolar response was observed with free, complexed, phosphorylated, and dephosphorylated forms of cTnI. Results were 4% lower in serum and 14% lower in EDTA plasma than in lithium heparin plasma ( P <0.01), independent of cTnI concentration. Conclusion: AccuTnI is a sensitive and precise assay for the measurement of cTnI.

Human neutrophil lipocalin is a unique marker of neutrophil inflammation in ulcerative colitis and proctitis

Abstract: Background and aim: Accumulation and infiltration by neutrophil granulocytes is a prominent feature in the local inflammatory process in ulcerative colitis (UC). The present study was performed to evaluate human neutrophil lipocalin (HNL) as a specific neutrophil marker in the inflamed lesions of the colon and rectum in patients with colitis and proctitis. Methods: The activity of intestinal neutrophils with respect to release of granule proteins was studied in 18 patients with UC (10 with colitis and eight with isolated proctitis) and in 18 healthy controls using perfusion fluid and biopsies from the sigmoid colon and rectum. The released amounts of the neutrophil granule proteins HNL and myeloperoxidase (MPO) were determined by radioimmunoassays, and the location of HNL and MPO in biopsies from colonic mucosa was examined by immunohistochemistry. Results: Mucosal release of HNL and MPO was increased 10–55-fold in patients with colitis and proctitis compared with controls. Their bowel biopsies demonstrated that only neutrophils were stained with anti-HNL. We also found correlations between HNL and levels of granulocyte/macrophage-colony stimulating factor (GM-CSF) and interleukin 8 (IL-8) in perfusion fluids from the sigmoidal segments of patients with proctitis, between HNL and GM-CSF in rectal segments in patients with proctitis, and in sigmoidal segments in patients with colitis. Conclusion: We conclude that the increased release of HNL and MPO in colorectal perfusion fluids indicates neutrophil involvement in the local inflammatory process, and suggest that HNL may serve as a specific marker of intestinal neutrophil activation in UC. GM-CSF, and to some extent IL-8, may play a role in neutrophil accumulation and priming in this disease.

Analysis of fluid-phase mediators.

Abstract: Sputum cellular indices are valid, reliable and responsive to change 1–7. Increasingly, numerous inflammatory mediators are being measured in the fluid phase of sputum; these include cytokines, chemokines, granulocyte proteins, markers of vascular leakage, eicosanoids, proteases and others. Many of these mediators are included in table 1⇓, which gives details of methods used by investigators to process sputum and measure mediator levels. The table also provides the median/mean levels measured in studied subject groups to give an indication of the expected levels of these mediators in sputum. However, the reproducibility, precision and validity of many of these measurements in sputum have not been investigated and, therefore, their utility as a research and clinical tool remains uncertain and requires confirmation. The following issues are important in the analysis of mediators: 1) choice of methods for measuring fluid­phase mediators; 2) points to consider when planning an immunoassay; and 3) evaluation of the measurement of a soluble mediator in sputum, i.e. validation of the measurement method. The three main types of method used for the measurement of sputum fluid­phase mediators are bioassays, enzyme assays and immunoassays. ### Bioassays Bioassays rely on the retention of biological activity and the ability to exert a measurable effect, such as proliferation of cells, bone marrow colony formation or chemotaxis 3, 11, 58. Sputum processing with mucolytics such as dithiothreitol (DTT) or dithioerythritol, which are strong reducing agents, may decrease the biological activity of cytokines, many of which rely on disulphide bonds to provide a stable structure for bioactivity. Bioassays also have the disadvantage of being inconvenient, time­consuming and lacking in specificity 59. In addition, the presence of commonly occurring endogenous cytokine inhibitors, although allowing an estimate of net activity, may result in significant underestimation of total cytokine levels 58. ### Enzyme assays Many …

Cell specific markers for eosinophils and neutrophils in sputum and bronchoalveolar lavage fluid of patients with respiratory conditions and healthy subjects

Abstract: Background: Highly specific protein markers for eosinophils and neutrophils could be a valuable diagnostic aid in various respiratory disorders. The cell specificity of monoclonal antibodies against eosinophil peroxidase (EPO), eosinophil cationic protein (ECP), human neutrophil lipocalin (HNL), and myeloperoxidase (MPO) was investigated using immunocytochemical techniques. Methods: Induced sputum and bronchoalveolar lavage fluid samples from 14 patients with respiratory conditions and four healthy individuals were studied. Antigens were detected at their intracellular sites in cells with well preserved structures using optimal techniques for fixation, permeabilisation, and immunolabelling. Results: Anti-EPO antibodies reacted only with eosinophils, and anti-HNL antibodies only with neutrophils. Anti-ECP antibodies reacted with both eosinophils and neutrophils and anti-MPO antibodies with neutrophils and monocytes. Cells not stained by monoclonal anti-EPO and anti-HNL antibodies included lymphocytes, monocytes, macrophages, squamous epithelial cells, and ciliated epithelial cells. Conclusions: EPO, a unique component of eosinophils, and HNL, a unique component of neutrophils, are useful markers for the identification of eosinophils and neutrophils, respectively, in sputum and bronchoalveolar lavage fluid.

Expression of the C5a receptor (CD88) on granulocytes and monocytes in patients with severe sepsis

Abstract: Introduction Treatment of patients with severe sepsis with agents antagonising the effects of C5a has been proposed based on beneficial effects in animal experiments and in vitro studies demonstrating upregulation of the C5a receptor (CD88) on granulocytes by endotoxin.

Polymorphism of the eosinophil cationic protein-gene is related to the expression of allergic symptoms.

Abstract: Summary Background We have found a polymorphism in the ECP (eosinophil cationic protein)-gene at position 434 according to GenBank accession number NM 002935. This polymorphism would cause the change of the amino acid arginine (base at position 434 is G) at position 97 to threonine (base at position 434 is C). Objective To investigate the prevalence of the ECP-polymorphism and to screen for disease associations. Methods DNA of 209 medical students and 76 asthmatic subjects was analysed. The 434 genotype in the ECP-gene was detected by cleavage of the amplified DNA sequence with the restriction enzyme PstI and analysis of the cleaved product by agarose gel electrophoresis. Results The prevalences of the polymorphism in the student population were 53%, 39% and 8% for the 434GG, the 434GC and the 434CC genotype, respectively, with allele frequencies of 72% (434G) and 28% (434C). Subjects reporting allergy had a higher prevalence of the 434G allele than non-allergic subjects (P = 0.0056). Of the students who were Phadiatop-positive and had allergic symptoms, 79% had the 434GG genotype, whereas the 434GC and 434CC genotypes were present in 82% of those who did not express allergic symptoms (P < 0.001). Among the 76 patients with asthma, patients with allergic asthma had a significantly higher proportion of 434GG compared with patients with non-allergic asthma (P = 0.04). None of the 18 subjects of the two groups with the 434CC genotype had allergy. Conclusion The 434(G > C) polymorphism in the ECP-gene is related to the development of allergic symptoms, suggesting a central role for the ECP molecule in the process.

Eosinophil cationic protein is stored in, but not produced by, peripheral blood neutrophils

Abstract: Summary Background Eosinophil cationic protein (ECP) is an eosinophil-derived protein, which has been shown to be present in circulating neutrophils. Objective To establish whether ECP is produced or internalized by peripheral blood neutrophils. Methods This was done using microscopy, flow cytometry, fractionation of cells and RT-PCR techniques. Results No ECP mRNA was detected after extensive cell purification to eliminate all traces of contaminating eosinophils. Examination of immunostained neutrophils by light, confocal, electron microscopy together with cell fraction experiments, established that ECP is present intracellularly and is mostly associated to cell granules. Uptake studies by flow cytometry and by using both cold and radiolabelled ECP showed that it is internalized by neutrophils and stored in some proportion in their primary granules. Upon stimulation with serum-treated Sephadex particles, the internalized ECP was partially released from cells. Conclusion ECP is not produced but can be internalized by circulating neutrophils, which take it from the environment and partially store it in their primary granules.

The impact of atopy on neutrophil activity in middle ear effusion from children and adults with chronic otitis media

Abstract: OBJECTIVE: To identify the relationship of neutrophil activity to allergy as reflected by the level of myeloperoxidase (MPO) in ears of atopic patients with chronic otitis media with effusion (OME) by objective testing. DESIGN: Evidence of neutrophils was measured in the effusion of atopic patients with chronic OME. Atopy was determined by intradermal and/or in vitro testing of allergic reaction to 10 inhalants, 2 molds, and 5 foods. SUBJECTS: Effusion MPO was measured prospectively in 138 ears from 106 consecutive patients with chronic OME. RESULTS: A total of 86 (81%) of 106 patients with OME tested atopic by in vitro or in vivo testing. Excluding 36 ears with purulence, the mean MPO level was 3132 microg/L in 84 atopic vs 142 microg/L in 18 nonatopic ears (P<.001). A total of 78 (90%) of 87 patients with OME were atopic. CONCLUSIONS: The surprising finding of marked elevation of effusion MPO in atopic patients but very low levels in nonatopic patients (P < .001) suggests that atopy may contribute to elevated levels of neutrophil activity in OME. An atopic patient may respond differently from a nonatopic one to the microbial or viral products of acute inflammation owing to the presence of primed inflammatory cells. This study provides confirmation on a cellular level that neutrophils are an integral part of the inflammatory process in OME to a disproportionate degree among atopic patients.