Myocarditis
Andreas P. Kalogeropoulos, Hal A. Skopicki, Javed Butler in Heart Failure, 2023
The Dallas histopathologic criteria were the first criteria used for the diagnostic and prognostic evaluation of myocarditis and included a qualitative assessment of the intensity of inflammation and (non-ischemic) necrosis.47 In the absence of necrosis, myocarditis is considered borderline. The main drawback of the Dallas criteria was the low sensitivity and high inter-observer variability. The use of quantitative immunohistochemical criteria has overcome these limitations, with inflammation defined as ≥14 leucocytes/mm2.2,9 Immunochemistry can further distinguish between B cells (CD20+) and T cells (CD3+), as well as various T cell subpopulations.5 In cases of dilated cardiomyopathy, ongoing inflammation is observed in 30% of EMBs.48
The Evolution of MAbs from Research Reagents to Mainstream Commercial Therapeutics
Maurizio Zanetti, J. Donald Capra in The Antibodies, 1999
Although the specificity of an antibody for its antigen is rather high, the same is not always true of the distribution of antigen expression. Antigens thought to be specific for a given cell type are often expressed on other tissues, sometimes unexpectedly. Therefore, before embarking on clinical trials it is necessary to establish that the reactivity of an antibody follows the predicted distribution. Typically, a panel of approximately 25–30 normal human tissues are evaluated by immuno-histochemistry. The value of immunochemistry in studying the expression of a given antigen is that it allows evaluation of microanalytical detail and heterogeneity. The limitations to this approach are (1) false negatives due to a low level expression or very restricted distribution of an antigen, or (2) false positives, due to binding of the antibody to similar epitopes, or epitopes shared by other antigens. This is usually addressed by using the highest concentration of antibody that does not show nonspecific binding. In addition, positive and negative cells or cell lines are used to set the upper and lower limits of antigen expression. Labeling can be by biotin or other similar moieties that allow easy detection by standard immunohistological techniques. Tissue cross-reactivity studies should generally be conducted in adherence to the FDA GLP regulations (Title 21 CFR Part 58, 1987; Federal Register, 1997).
The Inducible System: History of Development of Immunology as a Component of Host-Parasite Interactions
Julius P. Kreier in Infection, Resistance, and Immunity, 2022
The development of immunochemistry contributed to the development of the understanding of immunology in other ways than through the elucidation of the nature of antibody. It also put immunology on a firm experimental basis through the development of methods for the precise quantitative analysis of antigens and antibodies. Experimentation at the Rockefeller institute in the 1930s led to the development of quantitative precipitation methods for measuring antigen and antibody, and to the discovery that carbohydrates, as well as proteins, are antigenic. At the same time, scientists at the Rockefeller Institute discovered how antigen and antibody react to form insoluble lattice-like complexes (Figure 5.12).
Influence of Biochemical Cues in Human Corneal Stromal Cell Phenotype
Published in Current Eye Research, 2019
Julia Fernández-Pérez, Mark Ahearne
Expression of these markers was further analyzed with immunochemistry. While expression of ALDH3A1 was down-regulated at the mRNA level, staining showed positive cells in some conditions. Cells with a dendritic morphology showed more intense staining, especially when treated with ITS, IGF-1, IBMX, RA and in the serum-free control. Very low staining was seen in cultures treated with PDGF-BB, FBS, TGF-β1 and TGF-β3 (Figure 4a). Immunostaining of keratocan showed faint cytosolic staining in all conditions. When cells were treated with IGF-1, IBMX, ITS and RA, bright perinuclear staining was observed (Figure 4b). However, keratocan is a keratin sulphated proteoglycan that is deposited as ECM, hence was probably washed away during cell feedings. Expression of α-SMA correlated with expression of its gene ACTA2. Bright α-SMA stress fibers can be observed in cells treated with TGF-β1 and TGF-β3. Very sparse α-SMA+ cells were seen in treatments with AA and ITS (Figure 4c).
A profile of the binx health io® molecular point-of-care test for chlamydia and gonorrhea in women and men
Published in Expert Review of Molecular Diagnostics, 2021
Barbara Van Der Pol, Charlotte A. Gaydos
Epidemiologic, or syndromic, management of treatable STI is the only available standard of care in many settings across the globe. Due to common symptoms shared by several pathogens, over-treatment is frequent in the attempt to cure any pathogen that might be present [4]. For example, women with discharge are most commonly treated for chlamydia, gonorrhea, and trichomonas since any of these infections can cause cervical or vaginal discharge. This approach may be associated with increasing potential for antimicrobial-resistant gonococcal strains [5]. Furthermore, by definition, this management strategy fails to treat any asymptomatic infections since people without symptoms are not evaluated. Estimates of the frequency of asymptomatic infection range from 30% to 55% and 20% to 40% in women and men [6,7], respectively. Therefore, syndromic management is estimated to treat fewer than 30% of cases worldwide [4]. For many decades, the WHO has been calling for improved diagnostic solutions, which has resulted in the development of several point-of-care (POC) tests for chlamydia. However, these tests are, for the most part, antigen detection assays that rely on lateral flow immunochemistry (LFI) and have varied but generally unacceptably poor performance [4,8,9].
Managing hemolyzed samples in clinical laboratories
Published in Critical Reviews in Clinical Laboratory Sciences, 2020
Ana-Maria Simundic, Geoffrey Baird, Janne Cadamuro, Seán J. Costelloe, Giuseppe Lippi
Hemolysis interference in immunochemistry assays depends largely on the specific immunochemical method that is utilized. Homogeneous methods such as enzyme-multiplied immunoassay technique (EMIT), turbidimetry or particle-enhanced turbidimetric immunoassay (PETIA) all rely on measurements of light transmission, and would be expected to suffer from the presence of a significant concentration of cell-free hemoglobin that absorbs light at the wavelength used in the assay. Heterogenous methods such as chemiluminescent assays, however, where so-called “sandwiches” of antibodies and analytes are formed on the surface of solid supports, can be relatively free of the spectrophotometric interference of hemolysis, if they include a washing step that removes contaminating cell-free hemoglobin or other intracellular constituents prior to assay readout. Chemiluminescence as a detection strategy is in general resistant to spectrophotometric interference of hemolysis, because of low or absent intracellular concentrations of chemiluminescent constituents. Immunoassays suffer from hemolysis interference caused by chemical mechanism of interference. Namely, intracellular proteases in RBCs specifically degrade proteins (antigens or antibodies) involved in immunoassays. One important example of an analyte suffering from that type of interference mechanism is insulin [55]. No assay strategy can correct for this source of interference, as protein (antibodies and antigens) molecules in a hemolyzed sample are chemically modified (i.e. degraded) and undetectable with standard immunoassay reagents.