Nutrition as treatment
Geoffrey P. Webb in Nutrition, 2019
Skin prick tests are now widely used to identify causes of food allergy; small amounts of potential allergens are injected into the skin and the extent of any inflammatory skin reaction is then used to assess sensitivity. A positive skin test does not automatically mean that a person will have an allergic reaction to that substance when it is given by mouth although a negative response means that the substance is an unlikely cause of allergic symptoms. Skin prick tests are useful in confirming a suspected allergy and in deciding which foods might need to be considered in challenge tests. The radioallergosorbent test (RAST) is a more expensive alternative to skin prick tests; it assesses the amount of specific IgE present in a patient’s blood. The patient’s serum is reacted with an allergen which is adsorbed onto a solid paper matrix and the specific IgE in the serum will compete with added radioactive IgE for binding to this antigen. The more specific IgE there is in the patient’s blood the less radioactivity will remain on the paper.
Anisakis, Allergy and the Globalization of Food
Andreas L. Lopata in Food Allergy, 2017
Allergic anisakiasis, like the other forms of anisakiasis, is underreported in both healthcare statistics and the scientific literature. All forms of anisakiasis can result in subsequent sensitization to the Anisakis nematode (Audicana et al. 2008). Traditionally for the last thirty years, radioallergosorbent test using a blood sample (now referred to as allergen-specific IgE) has been primarily used to confirm allergic sensitisation to anisakid allergens post-anisakiasis (Desowitz et al. 1985). However, most patients who experience gastroenteritis and/or allergic symptoms after consuming fish will recover from their infection, never see a doctor specifically about this illness and consequently self-diagnose themselves as having food poisoning. If there is a later repeat of the symptoms upon re-ingestion of fish, the majority of patients will self-diagnose themselves with a fish allergy (Mourad et al. 2015).
In vitro Laboratory Tests for the Diagnosis of Allergy
Pudupakkam K Vedanthan, Harold S Nelson, Shripad N Agashe, PA Mahesh, Rohit Katial in Textbook of Allergy for the Clinician, 2021
Shortly after the discovery of IgE, the radioallergosorbent test (RAST) was introduced for the detection of allergen specific IgE in patient’s serum (Wide et al. 1967). As originally described this non-competitive, solid phase assay consisted of incubating a patient’s serum with an allergen that is conjugated to a cellulose paper disk that has been activated with cyanogen bromide (Ceska and Lundkvist 1972). If allergen-specific IgE is present, it binds to the paper disk and unbound antibodies are washed away after the incubation period. IgE bound to the allergen is then detected by the addition of a radiolabeled (typically 125I) antihuman IgE directed toward the Fc region. The amount of bound radiolabeled antihuman IgE is measured in a gamma counter and the radioactivity measured is proportional to the amount of allergen specific IgE present in the initial serum sample.
Allergy and Dry Eye Disease
Published in Ocular Immunology and Inflammation, 2021
Andrea Leonardi, Rocco Luigi Modugno, Elena Salami
In vitro assays such as radioallergosorbent test (RAST), capture or reverse enzyme-linked immunosorbent test (ELISA), or allergen microarrays are used in daily practice since they allow to search for a large number of allergen-specific IgE and results, presented in a semi-quantitative fashion, are more easily interpreted by non-allergy experts. However, in vitro assays are limited by the fact that only nanograms of specific IgE are present in the serum and allergen-specific serum IgG compete with IgE for allergen binding. Therefore, false-negative results are common.60,61 The skin prick test (SPT) is still considered the gold-standard for allergen-specific IgE detection. SPT false negatives are uncommon; so that negative results make the presence of IgE-mediated allergic reactivity unlikely. Similarly, positive results must always be interpreted in conjunction with the clinical findings. Differently from in vitro assays, SPT also allows for the measurement of IgE biological activity.62–64
Association of upper and lower airway eosinophilic inflammation with response to omalizumab in patients with severe asthma
Published in Journal of Asthma, 2020
Makoto Kurokawa, Toshiyuki Koya, Hiroyuki Takeuchi, Masachika Hayashi, Takuro Sakagami, Kojiro Ishioka, Yasuhiro Gon, Takashi Hasegawa, Toshiaki Kikuchi
The study participants included 16 patients (12 women and 4 men) diagnosed with severe asthma and perennial allergies, as determined by the radioallergosorbent test (RAST). These patients were treated with omalizumab in combination with high dose ICS and a long-acting β-agonist at the Niigata University Medical and Dental Hospital from September 2011 to August 2015. The criteria for severe asthma have been reported previously [3]. Omalizumab doses were calculated, based on the total serum IgE levels and the patients’ body weight, based on the manufacturer’s instructions. This study was conducted in accordance with the Ethical Principles for Medical Research Involving Human Subjects, the Declaration of Helsinki, and with the approval of the Ethics Committee of Niigata University (approval no. 956). All participants provided written informed consent before enrollment.
Analysis of allergic reaction in IgG4-related disease
Published in Modern Rheumatology, 2019
Motohisa Yamamoto, Ken-ichi Takano, Ryuta Kamekura, Satsuki Aochi, Chisako Suzuki, Shingo Ichimiya, Hiroki Takahashi
At the first visit, we interviewed the subjects regarding their allergic symptoms, determined the peripheral eosinophil counts, measured the levels of serum IgG, IgG4, and IgE, and performed screening for IgEs against specific allergens. We used the following enzyme-linked immunosorbent assay (ELISA) kits: Human IgG ELISA Kit (ab100547, Abcam, Cambridge, UK) and IgG4 Human ELISA Kit (BMS2095, Thermo Fisher Scientific K.K., Yokohama, Japan). The levels of serum IgE were measured using the radioimmunosorbent test. For the screening, IgEs against specific allergens were measured using the radioallergosorbent test. The following allergens were evaluated by fluorescence Enzyme Immunoassay: birch pollen, cedar pollen, moth scales, Dermatophagoides pteronyssinus, Poaceae pollens, weed pollens, food allergens, grain allergens, animal epithelia, and mold allergens. We measured specific IgEs using CAP system (Phadia 1000TM, Thermo Fischer Scientific Inc., Uppsala, Sweden). We analyzed for correlations between the laboratory data, including the peripheral eosinophil counts and the levels of serum IgG4 and IgE. We also compared the clinical features between the patients with IgEs against specific allergens (the positive group) and the patients without IgEs against specific allergens (the negative group).
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