Journal: Current allergy and asthma reports
Peanut seeds are currently widely used as source of human food ingredients in the United States of America and in European countries due to their high quality protein and oil content. This article describes the classification and molecular biology of peanut seed allergens with particular reference to their cross-reactivities. Currently, the IUIS allergen nomenclature subcommittee accepts 12 peanut allergens. Two allergens belong to the cupin and four to the prolamin superfamily, and six are distributed among profilins, Bet v 1-like proteins, oleosins, and defensins. Clinical observations frequently report an association of peanut allergy with allergies to legumes, tree nuts, seeds, fruits and pollen. Molecular cross-reactivity has been described between members of the Bet v 1-like proteins, the non-specific lipid transfer proteins, and the profilins. This review also addresses the less well-studied cross-reactivity between cupin and prolamin allergens of peanuts and of other plant food sources and the recently discovered cross-reactivity between peanut allergens of unrelated protein families.
Vaping is gaining popularity in the USA, particularly among teens and young adults. While e-cigs are commonly represented as safer alternatives to tobacco cigarettes, little is known regarding the health effects of their short- or long-term use, especially in individuals with pre-existing respiratory diseases such as asthma. Flavored e-cig liquids (e-liquids) and e-cig aerosols contain airway irritants and toxicants that have been implicated in the pathogenesis and worsening of lung diseases. In this review, we will summarize existing data on potential health effects of components present in e-cig aerosols, such as propylene glycol, vegetable glycerin, nicotine, and flavorings, and discuss their relevance in the context of asthma.
Although rodent allergy has long been recognized as an occupational disease, it has only been in the past decade that it has been recognized as a community-based disease that affects children. Most homes in the US have detectable mouse allergen, but the concentrations in inner-city homes are orders of magnitude higher than those found in suburban homes. Home mouse allergen exposure has been linked to sensitization to mouse, and children with asthma who are both sensitized and exposed to high mouse allergen concentrations at home are at greater risk for symptoms, exacerbations and reduced lung function. Rat allergen is found primarily in inner-city homes and has also been linked to asthma morbidity among sensitized children. The objective of this review is to summarize the scientific literature on rodents and their allergens, the effects of exposure to these allergens on allergic respiratory disease, and to make recommendations, based on this evidence base, for the evaluation and management of mouse allergy in the pediatric population.
Anaphylaxis is a severe allergic reaction that can be rapidly progressing and fatal. In instances where the triggering allergen is not known, establishing the etiology of anaphylaxis is pivotal to long-term risk management. Our recent work has identified a novel IgE antibody (Ab) response to a mammalian oligosaccharide epitope, galactose-alpha-1,3-galactose (alpha-gal), that has been associated with two distinct forms of anaphylaxis: (1) immediate onset anaphylaxis during first exposure to intravenous cetuximab, and (2) delayed onset anaphylaxis 3-6 h after ingestion of mammalian food products (e.g., beef and pork). The results of our studies strongly suggest that tick bites are a cause, if not the only significant cause, of IgE Ab responses to alpha-gal in the southern, eastern and central United States. Patients with IgE Ab to alpha-gal continue to emerge and, increasingly, these cases involve children. This IgE Ab response cross-reacts with cat and dog but does not appear to pose a risk for asthma; however, it may impair diagnostic testing in some situations.
Celiac disease (CD) is an autoimmune condition affecting the small intestine, triggered by the ingestion of gluten, the protein fraction of wheat, barley, and rye. There is a strong linkage between CD and HLA-DQ2 and HLA-DQ8 haplotypes. Multiple case reports and small series suggest concordance between CD and other autoimmune disorders. This paper provides a brief overview of the pathogenesis of CD and reviews the literature regarding associations between CD and other autoimmune diseases, including the potential effects of gluten-free diet therapy on the prevention or amelioration of associated diseases.
Clinical practice always necessitates proper diagnosis and correct treatment. For most clinical fields, determining the cause of the illness is irrelevant to the intervention. An oncologist, for example, has no need to explore the “cause” of the patient’s lymphoma. Allergists, by contrast, have tools and the need to examine the relevant allergen which is the putative “cause” of the patient’s allergic symptomatology. In the context of a legal claim, the “cause” of the symptoms or disorder is central, because it determines financial responsibility. However, in the case of an allergic disorder and identified allergen, a claim requires more. Whose allergen? Where did it come from? These are crucial questions that must be answered. This paper explores the approaches to causal assessment which are important for the clinical allergist as he/she navigates the interface between clinical practice and legal proceedings. Its purpose is to help the allergist understand that interface, and to be prepared to enter an unfamiliar legal arena.
Food allergies are estimated to affect as many as 8 % of children with 2.5 % being allergic to peanut products. Based on the results of recent surveys, this prevalence has been increasing over the last few decades for unknown reasons. As children with food allergies reach school age, the issue is becoming more common in schools. For that reason, schools are now required to be prepared to take responsibility for the safety of food-allergic students. This review discusses the common problems surrounding management of food allergies in the school setting along with reasonable recommendations for addressing those problems. The most important component of food allergy management is for the student to get an accurate diagnosis and to then discuss development of an anaphylaxis action plan with their health-care provider. Each school should insist that a copy of such a plan be provided for each student with food allergy and that epinephrine is readily available should a student have an anaphylactic reaction. In addition to epinephrine, it is essential that school personnel be properly trained to recognize and treat allergic reactions should they occur. Known deficiencies in school preparedness have been documented in previous literature, and consequently, both state and the federal government have begun to implement policies to help with school preparedness.
Increasing evidence suggests that intake of long-chain polyunsaturated fatty acids (LCPUFA), especially omega-3 LCPUFA, improves respiratory health early in life. This review summarizes publications from 2009 through July 2012 that evaluated effects of fish, fish oil or LCPUFA intake during pregnancy, lactation, and early postnatal years on allergic and infectious respiratory illnesses. Studies during pregnancy found inconsistent effects in offspring: two showed no effects and three showed protective effects of omega-3 LCPUFA on respiratory illnesses or atopic dermatitis. Two studies found that infants fed breast milk with higher omega-3 LCPUFA had reduced allergic manifestations. Earlier introduction of fish improved respiratory health or reduced allergy in four studies. Three randomized controlled trials showed that providing LCPUFA during infancy or childhood reduced allergy and/or respiratory illness while one found no effect. Potential explanations for the variability among studies and possible mechanisms of action for LCPUFA in allergy and respiratory disease are discussed.
Rhinitis is a multifactorial disease characterized by symptoms of sneezing, rhinorrhea, postnasal drip, and nasal congestion. Non-allergic rhinitis is characterized by rhinitis symptoms without systemic sensitization of infectious etiology. Based on endotypes, we can categorize non-allergic rhinitis into an inflammatory endotype with usually eosinophilic inflammation encompassing at least NARES and LAR and part of the drug induced rhinitis (e.g., aspirin intolerance) and a neurogenic endotype encompassing idiopathic rhinitis, gustatory rhinitis, and rhinitis of the elderly. Patients with idiopathic rhinitis have a higher baseline TRPV1 expression in the nasal mucosa than healthy controls. Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is the active component of chili peppers, plants of the genus Capsicum. Capsaicin is unique among naturally occurring irritant compounds because the initial neuronal excitation evoked by it is followed by a long-lasting refractory period, during which the previously excited neurons are no longer responsive to a broad range of stimuli. Patients with idiopathic rhinitis benefit from intranasal treatment with capsaicin. Expression of TRPV1 is reduced in patients with idiopathic rhinitis after capsaicin treatment. Recently, in a Cochrane review, the effectiveness of capsaicin in the management of idiopathic rhinitis was evaluated and the authors concluded that given that many other options do not work well in non-allergic rhinitis, capsaicin is a reasonable option to try under physician supervision. Capsaicin has not been shown to be effective in allergic rhinitis nor in other forms of non-allergic rhinitis like the inflammatory endotypes or other neurogenic endotypes like rhinitis of the elderly or smoking induced rhinitis.
IgG4 is the least abundant IgG subclass in human serum, representing less than 5 % of all IgG. Increases in IgG4 occur following chronic exposure to antigen and are generally associated with states of immune tolerance. In line with this, IgG4 is regarded as an anti-inflammatory antibody with a limited ability to elicit effective immune responses. Furthermore, IgG4 attenuates allergic responses by inhibiting the activity of IgE. The mechanism by which IgG4 inhibits IgE-mediated hypersensitivity has been investigated using a variety of model systems leading to two proposed mechanisms. First by sequestering antigen, IgG4 can function as a blocking antibody, preventing cross-linking of receptor bound IgE. Second IgG4 has been proposed to co-stimulate the inhibitory IgG receptor FcγRIIb, which can negatively regulate FcεRI signaling and in turn inhibit effector cell activation. Recent advances in our understanding of the structural features of human IgG4 have shed light on the unique functional and immunologic properties of IgG4. The aim of this review is to evaluate our current understanding of IgG4 biology and reassess the mechanisms by which IgG4 functions to inhibit IgE-mediated allergic responses.