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Immunological Approaches
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Deborah E. Dixon, Susan J. Steiner, Stanley E. Katz
The phenomenon occurs when antibody connects with antigen to form large polymericlike structures that become insoluble because of the modifications of the polar groups responsible for solubility. One of the most common uses of this phenomenon is the agar diffusion, double diffusion, or Ouchterlony reaction. Here, antibody and antigen diffuse through agar, and where they meet, in concentrations meeting the equivalence zone of the precipitin reaction, a band will form. The precipitin line will form closest to the lower concentration of either the antibody or antigen source and is dependent upon which reagent is in excess.
Paracoccidioidomycosis
Published in Rebecca A. Cox, Immunology of the Fungal Diseases, 2020
Beatriz Jimenez-Finkel, Angela Restrepo-Moreno
In paracoccidioidomycosis, as in other deep mycoses, antibodies of multiple specificities, are produced in response to the fungus. These antibodies are detected both in patients with the disease and in experimental animals, using a variety of assays, such as immunodiffusion,57indirect immunofluorescence,58 complement fixation,59 and, more recently, an erythro-immunoassay,60 enzyme-linked immunosorbent assay,61,62 and magnetic enzyme-linked immunosorbent assay.63,64 Precipitins, detected by the tube dilution method, are the first antibodies to appear during the course of the disease, but they disappear quickly.65. When precipitins are evaluated by agar-gel procedures, the relationship to duration of the illness is difficult to establish; however, the number and duration of visible bands in immunodiffusion tests have been correlated with clinical activity.66 Since different methods and antigens have been used in experimental studies, variable patterns of specific and nonspecific bands have been observed.66,67 However, each detection method appears to be consistent, sensitive, and specific.68 Using a yeast-culture filtrate, three precipitin bands have been characterized. Band 1 is the most commonly detected and is specific for the disease. This precipitinogen is identical to that designated as Band E by Yarzabal et al.67 Band 2 is also specific but is not present in all cases. In contrast, Band 3 cross-reacts with the M antigen of Histoplasma capsulatum.57
Immunoglobulins
Published in Constantin A. Bona, Francisco A. Bonilla, Textbook of Immunology, 2019
Constantin A. Bona, Francisco A. Bonilla
When complementary antibodies and antigens are mixed in solution, complexes form and precipitate. The amount of precipitate is related to antigen and antibody valence, reactant concentrations, and antibody affinity, which also may depend on the pH and ionic strength of the solution. Precipitation requires antibody and antigen valences greater than one; an Fab fragment cannot precipitate antigen. Similarly, a monovalent antigen cannot interact with more than one antibody. Since secreted IgM molecules are pentameric (10 combining sites) they are very good precipitators. Figure 4–17 shows a typical precipitin curve, one method of measuring the reaction of antibody and antigen.
Comparative toxicological characterization of venoms of Cerastes cerastes and Macrovipera mauritanica from Morocco and neutralization by monospecific antivenoms
Published in Toxin Reviews, 2020
Bouchra Makran, Laila Fahmi, Lotfi Boussada, Naoual Oukkache, Fatima Chgoury, Hakima Benomar, Noreddine Ghalim, Mustapha Lkhider
The production of antivenoms (anti-Cc and anti-Mm) as well as their immunoreactivity in front of two crude venoms and their purified fractions was initially controlled all along the immunization schedule according to the method described by Ouchterlony and Nilsson (1978). Immunodiffusion was carried out in gels 1% agarose–PBS with a concentration of 0.01% sodium azide. Central wells were loaded with 10 µL of undiluted antivenoms and the six peripheral wells with 2 µg/µL of crude venoms or their fraction purified. The glass slides were incubated at 25 °C for 24 at 48 h and precipitate bands were observed after staining with Coomassie Blue R250 and washing with methanol acetic acid. Developing of precipitin lines by serum indicated the presence of antivenom antibodies.
Endemic pulmonary fungal diseases in immunocompetent patients: an emphasis on thoracic imaging
Published in Expert Review of Respiratory Medicine, 2019
Ana Luiza Di Mango, Gláucia Zanetti, Diana Penha, Miriam Menna Barreto, Edson Marchiori
The diagnostic criteria for aspergilloma include respiratory symptoms, CT features (over a period of three month) and direct evidence of infection or immunological response to Aspergillus species. The majority of patients present with positive A. fumigatus IgG or precipitins. The diagnostic criteria for ABPA were reviewed in 2013. After a positive skin prick test, serologic workup for IgE, A. fumigatus specific IgG and total eosinophil count is made, also taking into account predisposing conditions such as asthma and cystic fibrosis. Positive diagnosis is given with positive skin test and IgE more than1000IU/ml [67,69].
Acute histoplasmosis in travelers: a retrospective study in an Italian referral center for tropical diseases
Published in Pathogens and Global Health, 2020
Silvia Staffolani, Niccolò Riccardi, Claudio Farina, Giuliana Lo Cascio, Maurizio Gulletta, Federico Gobbi, Paola Rodari, Tamara Ursini, Giulia Bertoli, Niccolò Ronzoni, Zeno Bisoffi, Andrea Angheben
The serological test used in the study was the detection of precipitins by immunodiffusion (ID) to the H and M antigen of Histoplasma capsulatum (ID Fungal Antibody system- IMMY Inc. Norman, OK USA) [31]. The definitive diagnosis was made by cultivation of the organism from respiratory samples for 4 weeks, Broncoalveolar Lavage (BAL) in Sabouraud dextrose agar at 24°C and brain heart infusion agar at 37°C to obtain the yeast phase. Isolation of the pathogen required 1–2 weeks and identification was done on the basis of evidence of specific warted macroconidia of Histoplasma capsulatum and conversion to the yeast phase.