Inflammation and the Immune System
Jeremy R. Jass in Understanding Pathology, 2020
An excessive response by the immune system to an antigenic stimulus that is damaging to the host is described as hypersensitivity. The antigen may be exogenous or derived from within the organism itself. The latter is described as autoimmunity and is discussed in Chapter 30. The Gell and Coombs classification of hypersensitivity reactions (Table 3) stems from the days of old immunology. Types I, III and IV hypersensitivity were described initially in 1902, 1905 and 1891 respectively (Bordley & Harvey, 1976). Only type IV hypersensitivity recognises the participation of the T lymphocyte. A single disease process may implicate two or more types of hypersensitivity. For example, types I, III and IV hypersensitivity are implicated in pulmonary aspergillosis (fungal infection) and types II and IV participate in antibody-dependent cellular cytotoxicity (ADCC). Type III hypersensitivity is responsible for most types of glomerulonephritis, yet this group of kidney disorders shows considerable variability in terms of morphology, natural history and prognosis. This is explained at least in part by the size and number of immune complexes bombarding the glomerulus. The classification of hypersensitivity given in Table 3 is therefore an oversimplification but still retains its popularity.
Formaldehyde
William J. Rea, Kalpana D. Patel in Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
We do not know the percentage of patients sensitive to formaldehyde nor do we understand all the mechanisms involved in the development of this sensitivity. We do know that beside the IgE and IgG mechanisms, a nonimmune reaction occurs. This involves cell membrane disturbance. The formaldehyde can make the membrane rest pores with K+ leaking out and Ca2+ and N+ entering the cells, Ca2+ combines with Kinase A and C which is then phosphorylated. This increases sensitivity up to 1000 times.135 This likely is the mechanism of the hypersensitivity. In testing over 1000 patients with symptoms, however, we found that those who react positively to challenge have usually improved after being shown how to reduce their environmental chemical overload through both cleaning up their environment and changing their lifestyle in order to reduce their exposures and hence their total body load. ATP supplementation appears to help the chemically sensitive's energy.
Physiology of the immune system
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2015
After reading this chapter, the reader should be able to Differentiate the innate and adaptive immune system.Describe the passive mechanisms by which the body resists infection.Explain how the body recognizes invading organisms.Describe the natural immune system.Describe the complement system and explain its function.Describe the adaptive immune system and the role of lymphocytes.Outline the role of immunoglobulins.Differentiate and explain the clinical significance of hypersensitivity reactions.
Biological effects of metal degradation in hip arthroplasties
Published in Critical Reviews in Toxicology, 2018
Donatella Granchi, Lucia Maria Savarino, Gabriela Ciapetti, Nicola Baldini
The hypersensitivity reactions are abnormal or pathologic immune responses to repeated exposure to an antigen in predisposed individuals. Type-IV hypersensitivity (delayed hypersensitivity) is undoubtedly the hypersensitivity reaction to metal device that has been more studied over the last five decades. Metal ions act as haptens since they bind to the protein carrier, thus modifying their structure and eliciting an immune response against a non-self-substance. Similarly, the adaptive immune response may be triggered by metal nanoparticles covered by a so-called “protein corona” (Lundqvist 2013). The layer is deposited following the interaction of particles with biological fluids or the clearing of wear debris by phagocytes. Depending on size, shape and surface charge of the particle, the proteinaceous layer may consist of an inner “hard” and outer “soft” layer (Corbo et al. 2016). As a consequence, the adsorbed proteins may undergo secondary and tertiary structure conformational changes that, ultimately, lead to “non-self” biological entities (Simoes et al. 2015; Corbo et al. 2016). Ni, Co, Cr, and V are the most sensitizing agents, while reactions to Ti or Al are very rare (Granchi et al. 2008). Novel metal–protein complexes may be active in periprosthetic tissue, in synovial fluid, or far from the implant when disseminated through the lymphatic and vascular systems (Coleman et al. 1973; Cadosch et al. 2009).
Allergy to acrylate in composite in an orthodontic patient: a case report
Published in Journal of Orthodontics, 2018
Sophy K. Barber, Harmeet K. Dhaliwal
Hypersensitivity reactions occur as a result of immune reaction to innocuous antigens. Type I reactions arise in genetically predisposed individuals following internalisation of an allergen, resulting in an immediate immunoglobulin E-mediated release of histamine and other immunological mediators. In dentistry, Type I reactions are most commonly associated with latex and nickel. Type IV reactions are mediated by T-cells and present as a delayed reaction, typically 48–72 hours after antigen exposure (Wiltshire and Noble 2007). Latex is the most common cause of Type IV hypersensitivity reactions but the number of reports of acrylate allergy in dental personnel is increasing (Syed et al. 2015). The most common presentation in dental professionals is contact dermatitis resulting from direct contact with various uncured monomers (Aalto-Korte et al. 2007). This can cause itching, burning, scaling and blistering confined to the areas of contact (Prasad Hunasehally et al. 2012).
Self-reported beta-lactam intolerance: not a class effect, dangerous to patients, and rarely allergy
Published in Expert Review of Anti-infective Therapy, 2019
Words matter. What something is called influences how people think about it. When allergies to beta-lactams are reported within the medical record, many providers fear the possibility of an anaphylactic reaction or a serious cutaneous adverse reaction (SCAR) occurring with any subsequent administration of that, or any other, beta-lactam. The word ‘allergy’ should not be used to describe most cases of suspected or reported penicillin, or any other beta-lactam, intolerance [28]. Unconfirmed or incompletely characterized adverse reactions should be labeled by default as adverse and not allergic in the electronic health record (EHR). Hypersensitivity is the term that should be reserved to describe immunologically mediated adverse drug reactions. Allergy is a very specific subgroup of hypersensitivity, mediated through mast cell activation, typically via antigen-specific IgE bound to the mast cells. It is possible to desensitize individuals with true allergy and safely give them the needed penicillin or other beta-lactams [6]. Tolerance implies the individual did not have a problem with the last exposure.
Related Knowledge Centers
- Autoimmunity
- Immunoglobulin E
- Immunoglobulin M
- Type I Hypersensitivity
- Type II Hypersensitivity
- Type III Hypersensitivity
- Immune System
- Allergy
- Immunoglobulin G
- Type II Hypersensitivity
- Type III Hypersensitivity
- Complement System