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Parasite Versus Host: Pathology and Disease
Published in Eric S. Loker, Bruce V. Hofkin, Parasitology, 2023
Eric S. Loker, Bruce V. Hofkin
Granulomas are a common outcome in many parasitic infections. They result from a delayed-type hypersensitivity response (DTH). Such a response relies on components of both innate and adaptive immunity. A DTH response begins when antigen-presenting cells release cytokines that both attract and activate Th-1 cells. If these Th-1 cells recognize their specific antigen on the surface of an antigen-presenting cell, they respond by releasing inflammatory cytokines, including interferon γ (IFN-γ) and tissue necrosis factor-α (TNF-α). These cytokines cause increased macrophage activation, leading to a positive feedback cycle that ultimately causes destruction of local tissue and the formation of the granuloma. The granulomas that form in response to Mycobacterium tuberculosis infection, called tubercles, are perhaps the textbook example of this type of pathology. An impressive roster of eukaryotic pathogens, ranging from protozoa like Toxoplasma gondii to helminths such as cestodes and schistosomes also provoke granuloma formation. In the case of schistosomes, it is the response to egg antigens rather than to the adults that triggers granuloma formation. For an example of parasite induced-granuloma formation of interest to veterinarians and horse owners, see Box 5.1.
AI and the Bioscience and Clinical Considerations for Immunology
Published in Louis J. Catania, AI for Immunology, 2021
After a susceptible person is exposed to an allergen, the body starts producing a large quantity of IgE antibodies. This results in the reoccurrence of the allergic response, sometimes with increasing intensity with each re-exposure to the allergen. Included among its cytokines, are histamine and heparin (mentioned above), which along with other inflammatory symptoms, produces itching. With the allergic and hypersensitivity response, symptoms can also include, sneezing, and congestion (from histamine release and degranulation of mast cells – in Figure 2.3). In their most severe form, allergy or hypersensitivity can produce a life-threatening condition call anaphylaxis and anaphylactic shock.13
Complications of Fillers and Their Management
Published in Neil S. Sadick, Illustrated Manual of Injectable Fillers, 2020
Approximately 3% of the population is at risk of developing an allergic reaction due to bovine collagen implants. Delayed hypersensitivity response or severe anaphylactic shock due to the collagen product are feared and serious side effects (42). Rare hypersensitive reactions include the formation of foreign body granulomas at the injection site (43,44), as well as cyst or abscess formation and necrosis (40,45). Therefore, a skin test is required 4 weeks before injection with bovine collagen (46,47). As most of the treatment-associated allergic reactions occur shortly after the first treatment, some authors recommend a second allergy test 2–3 weeks after negative first test to reduce the risk for hypersensitivity side effects (48,49). Human-derived collagen products do not include the risk of hypersensitive reactions (15).
Gold nanoparticles for preparation of antibodies and vaccines against infectious diseases
Published in Expert Review of Vaccines, 2020
A new strategy for preparing antibodies to tuberculin was described [129] that used the adjuvant properties of GNPs. Tuberculin is a mixture of the surface antigens of various types of mycobacteria (Mycobacterium tuberculosis, M. bovis, and M. avium). When injected intradermally, it causes a specific delayed-type hypersensitivity response in infected or vaccinated patients. Polyclonal antituberculin antibodies were raised by injecting 7.5 μg of tuberculin conjugated to 15-nm GNPs into rabbits four times intramuscularly. The obtained antibodies had a high titer, whereas in the control animals, which were given nonconjugated tuberculin, no antibodies were found in the blood serum. The antituberculin antibodies were used to detect mycobacteria by ELISA and by light and electron microscopy.
Two unusual cases of lacrimal sac inflammatory polyps with allergic mucin sine fungi
Published in Orbit, 2020
Imran Haq, Hardeep Singh Mudhar, Zanna Currie, Showkat Mirza, Sachin Salvi
Allergic fungal sinusitis (AFS) is a condition that typically presents with a history of nasal polyps, asthma, and allergies. Histology reveals layered mucin with entrapped effete and viable eosinophils in different stages of degranulation, termed allergic mucin. In many cases, although not all, fungal hyphae are present. The immunologic mechanism is thought to be a combined type I and type III immune hypersensitivity response.1,2There are also rare reports describing allergic mucin in the absence of fungi.3 There have been three previous cases of AFS affecting the lacrimal sac, two of which demonstrated fungi.4–6 Here, we present our experience of two cases of lacrimal sac involvement by allergic mucin with unique clinical and histopathological features.
Cross-reactivity between halogenated platinum salts in an immediate-type respiratory hypersensitivity model
Published in Inhalation Toxicology, 2018
David M. Lehmann, Wanda C. Williams
Asthma is a condition associated with narrowing of the airways leading to bouts of chest tightness, wheezing, coughing and shortness of breath. Occupational asthma is the most common occupational lung disease, accounting for up to 15% of asthma cases in the United States (ALA, 2008; Balmes et al., 2003; Blanc & Toren, 1999). Asthmatic reactions can be triggered by exposure to high concentrations of irritants (e.g. hydrochloric acid, sulfur dioxide, ammonia, smoke) or through the development of a type I hypersensitivity response (e.g. isocyanates, metals). Unlike irritant-induced asthmatic reactions which occur immediately after first exposure, type I hypersensitivity reactions occur after repeated work-related exposure to an allergy-inducing substance resulting in activation of an adaptive immune system response. Continued exposure to occupational asthmagens can intensify symptoms and lead to the development of lifelong asthma. Occupational asthma has the potential to not only adversely impact worker productivity, but to also decrease the quality of life for affected individuals. Consequently, identification and characterization of occupational asthmagens is paramount.