Fish allergy is one of the most common food allergies. The currently recommended treatment commonly consists of avoiding all fish species. Recent literature suggests that these recommendations are ...overprotective for the majority of fish-allergic patients. This review summarizes recent findings and provides practical information regarding management of fish allergy in the individual patient. After precise history taking supported by additional specific IgE measurements and/or skin prick tests, fish-allergic patients can generally be categorized into the following clinical clusters: (A) poly-sensitized patients reacting to all fish species due to their sensitization to the panallergen β-parvalbumin, (B) mono-sensitized patients with selective reactions to individual fish species only, and (C) oligo-sensitized patients reacting to several specific fish. A number of allergens including parvalbumin, enolase, and aldolase can be involved. Depending on the specific cluster the patient belongs to, oral food challenges for one or more fish species can be performed with the aim to provide safe alternatives for consumption. This way, several alternative fish species can be identified for mono- and oligo-sensitized patients that can safely be consumed. Notably, even poly-sensitized patients generally tolerate fish species low in β-parvalbumin such as tuna and mackerel, particularly when processed. Taken together, allergological evaluation of patients with a documented fish allergy should be strongly considered, as it will allow the majority of patients to safely reintroduce one or more fish species.
Accelerating the induction of tolerance to cow's milk (CM) reduces the burden of cow's milk allergy (CMA). In this randomised controlled intervention study, we aimed to investigate the tolerance ...induction of a novel heated cow milk protein, the iAGE product, in 18 children with CMA (diagnosed by a paedriatric allergist). Children who tolerated the iAGE product were included. The treatment group (TG:
= 11; mean age 12.8 months, SD = 4.7) consumed the iAGE product daily with their own diet, and the control group (CG:
= 7; mean age 17.6 months, SD = 3.2) used an eHF without any milk consumption. In each group, 2 children had multiple food allergies. The follow-up procedures consisted of a double-blind placebo-controlled food challenge (DBPCFC) with CM t = 0, t = 1 (8 months), t = 2 (16 months), and t = 3 (24 months). At t = 1, eight (73%) of 11 children in the TG had a negative DBPCFC, versus four out of seven (57%) in the CG (BayesFactor = 0.61). At t = 3, nine of the 11 (82%) children in the TG and five of seven (71%) in the CG were tolerant (BayesFactor = 0.51). SIgE for CM reduced from a mean of 3.41 kU/L (SD = 5.63) in the TG to 1.24 kU/L (SD = 2.08) at the end of intervention, respectively a mean of 2.58 (SD = 3.32) in the CG to 0.63 kU/L (SD = 1.06). Product-related AEs were not reported. CM was successfully introduced in all children with negative DBPCFC. We found a standardised, well-defined heated CM protein powder that is safe for daily OIT treatment in a selected group of children with CMA. However, the benefits of inducing tolerance were not observed.
Exocytosis and endocytosis are pivotal in many biological processes, but remain difficult to quantify. Here we combine a new algorithm for estimating vesicle size with a detailed morphological ...analysis of tip-growing cells, in which exocytosis is highly localized and therefore more readily quantified. Cell preservation was rendered as life-like as possible by rapid freezing. This allowed us to produce the first estimates of exocytosis rates in the root hairs and pollen tubes of the model plant Arabidopsis. To quantify exocytosis and endocytosis rates during cell growth, we measured the diameter of vesicles located in the tips of Arabidopsis root hairs and pollen tubes and the widths of cell walls and the cell lumen in longitudinal thin transmission electron microscopic sections. In addition, we measured growth velocities of Arabidopsis root hairs and pollen tubes, using video microscopy. The number of exocytotic vesicles required for cell wall expansion, and the amount of excess membrane inserted into the plasma membrane to be internalized, were estimated from the values that were obtained. The amount of excess membrane that is inserted into the plasma membrane during cell growth was estimated as 86.7% in root hairs and 79% in pollen tubes. This membrane has to be recycled by endocytosis. From counting of the total number of vesicles that is present in thin EM sections through the pollen tube tip, we estimated the average number of vesicles that is present in the tip of pollen tubes. By calculating the total amount of membrane and cell wall material that is required for continued cell growth, assuming that all vesicles are exocytotic, we estimated that pollen tubes continue to grow for 33 s when delivery of vesicles to the tip is inhibited. We arrested vesicle delivery to the tip by application of cytochalasin D. After cytochalasin D application, pollen tubes continued to grow for 30-40 s, which is in the same range as the estimated value of 33 s and shows that in this time frame, the availability of exocytotic vesicles is not a limiting factor.
ALEX multiplex array is a relatively new multiplex allergy test which analyses more than 120 allergen extracts and 170 molecular components. ISAC is the most used and studied multiplex array to date, ...offering 112 molecular components. In ten atopic children with multiple food allergies good agreement was observed between ALEX and ISAC sIgE results for nearly all shared food components. Presence of larger number of allergens in ALEX could help clinicians to improve personalized dietary advice. However more positive sensitizations with unknown clinical relevance were found by ALEX, potentially increasing clinical complexity. Pediatric allergists should be aware of this, especially in young atopic children with (severe) eczema who have not introduced all sorts of food yet.
Abstract
Background
Specific IgE (sIgE) against the peanut component Arachis hypogaea (Ara h) 2 has been shown to be the most important allergen to discriminate between peanut allergy and peanut ...tolerance. Several studies determined sIgE cut off values for Ara h 2, determined by singleplex measurements. However, cut off values for Ara h 2 from multiplex arrays are less well defined. The aim of this study was to evaluate the correlation between Ara h 2 sIgE determined by singleplex versus multiplex measurements and to assess the diagnostic value of the different peanut components included in Immuno Solid-phase Allergen Chip (ISAC) multiplex analysis in children with a suspected peanut allergy.
Methods
In this retrospective study we analyzed Ara h 2 sIgE values with singleplex Fluorescence Enzyme Immunoassay (FEIA, ImmunoCap) and multiplex microarray (ISAC) measurements in 117 children with a suspected peanut allergy. Also, other peanut components measured by ISAC were analyzed. Double blinded placebo controlled oral food challenges were used as golden standard.
Results
Among all studied peanut components FEIA Ara h 2 sIgE showed the highest area under the curve (AUC, 0.922), followed by ISAC Ara h 6 and Ara h 2 sIgE with AUCs of respectively 0.906 and 0.902. Best cut off values to diagnose peanut allergy were 4.40 kU/l for FEIA Ara h 2 sIgE and, 7.43 ISU and 8.13 ISU for respectively Ara h 2 and Ara h 6 sIgE in ISAC microarray. Ara h 2 sIgE determined in FEIA and ISAC showed a good correlation (r = 0.88; p < 0.01).
Conclusion
Ara h 6 and Ara h 2 sIgE in multiplex ISAC are both good predictors of clinical peanut allergy in Dutch children, and their performance is comparable to the use of Ara h 2 in singleplex FEIA. The simultaneous measurement of different peanut components using ISAC is an advantage and clinically useful to detect peanut allergic children that are Ara h 2 negative but sensitized to other peanut proteins such as Ara h 6.
Food Allergy and Asthma: Is There a Link? Emons, Joyce A. M.; Gerth van Wijk, Roy
Current treatment options in allergy,
2018/12, Letnik:
5, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Purpose of review
To describe and understand the links and interactions between food allergy and asthma
Recent findings
Food allergy and asthma are characterized by an increasing prevalence. ...Moreover, food allergy and asthma often coexist. Both conditions are associated with each other in different ways. It has been shown that food allergy is a risk factor of developing asthma. Atopic dermatitis appears to be the common denominator in this interaction. Loss-of-function variants of the filaggrin mutation result in an impaired epidermal barrier function and have been shown to be a risk factor for the development of atopic dermatitis, allergies, and asthma. Early introduction of food allergens and optimal treatment of the skin barrier are preventive interventions for the development of food allergy and asthma. Asthma is also a risk factor for the development of severe or even fatal anaphylaxis in patients with food allergy. Isolated asthma is not a feature of a food allergic reaction; however, respiratory symptoms may be part of anaphylactic reactions. In addition, during an allergic reaction to food, non-specific bronchial hyperreactivity may increase. Cross-reactive allergens may be responsible for asthma-associated food allergy. This is particularly true for severe asthma upon ingestion of snail in patients allergic to house-dust mites. Finally, airborne allergens from occupational sources such as wheat, fish, and seafood may induce asthmatic reactions. This phenomenon is sometimes seen in non-occupational settings.
Summary
Food allergy and asthma are interconnected with each other beyond the presence of simple comorbidity. Food allergy precedes and predisposes to asthma, and mutual interactions range from respiratory symptoms and bronchial hyperreactivity during food-induced anaphylaxis to severe asthma due to cross-reactive food allergens and to occupational asthma upon exposure to airborne allergens. Moreover, coexisting asthma in food allergies may result in severe and sometimes fatal anaphylactic reactions.
Tip‐growing cells have a particular lifestyle that is characterized by the following features: (1) the cells grow in one direction, forming a cylindrical tube; (2) tip‐growing cells are able to ...penetrate their growth environment, thus having to withstand considerable external forces; (3) the growth velocity of tip‐growing cells is among the fastest in biological systems. Tip‐growing cells therefore appear to be a system well suited to investigating growth processes. The cytoskeleton plays an important role in cell growth in general, which is why tip‐growing cells provide an excellent model system for studying this aspect. The cytoskeletal system comprises structural elements, such as actin filaments and microtubules, as well as proteins that link these elements, control their configuration or are responsible for transport processes using the structural elements as tracks. Common aspects as well as differences in configuration and function of the cytoskeleton in various types of tip‐growing cells reveal the general principles that govern the relationship between the cytoskeleton and cell growth.
Summary
Cellulose is the most abundant biopolymer on earth, and has qualities that make it suitable for biofuel. There are new tools for the visualisation of the cellulose synthase complexes in ...living cells, but those do not show their product, the cellulose microfibrils (CMFs). In this study we report the characteristics of cell wall textures, i.e. the architectures of the CMFs in the wall, of root hairs of Arabidopsis thaliana, Medicago truncatula and Vicia sativa and compare the different techniques we used to study them. Root hairs of these species have a random primary cell wall deposited at the root hair tip, which covers the outside of the growing and fully grown hair. The secondary wall starts between 10 (Arabidopsis) and 40 (Vicia) μm from the hair tip and the CMFs make a small angle, Z as well as S direction, with the long axis of the root hair. CMFs are 3–4 nm wide in thin sections, indicating that single cellulose synthase complexes make them. Thin sections after extraction of cell wall matrix, leaving only the CMFs, reveal the type of wall texture and the orientation and width of CMFs, but CMF density within a lamella cannot be quantified, and CMF length is always underestimated by this technique. Field emission scanning electron microscopy and surface preparations for transmission electron microscopy reveal the type of wall texture and the orientation of individual CMFs. Only when the orientation of CMFs in subsequent deposited lamellae is different, their density per lamella can be determined. It is impossible to measure CMF length with any of the EM techniques.
Allergic rhinitis is a common respiratory disease in children and sensitization to inhalant allergens plays a significant role in its development. However, limited knowledge exists regarding ...sensitization profiles of inhalant allergen components in atopic children, particularly in the very young individuals. Understanding these profiles could provide insights into the early development of allergic rhinitis. The objective of this cross-sectional retrospective study was to evaluate the IgE-sensitization profiles to multiple inhalant allergen components and their clinical relevance in Dutch atopic children, with specific focus on children under the age of 4 years.
A total of 243 atopic children were included in the study and sensitization profiles were analyzed using multiplex microarray analysis (ISAC). Clinical information was obtained from records of a pediatric allergy outpatient clinic between 2011 and 2020. Specific IgE responses to inhalation allergen components from five allergen sources (grass pollen, tree pollen, house dust mite, cat and dog), were examined. The study encompassed children of different age groups and compared those with and without symptoms.
The results demonstrated that sensitization to inhalant allergen components was present in 92% of the cohort. Sensitization was already evident at a young age (87%), including infancy, with a rapid increase in prevalence after 1 year of age. House dust mite emerged as the most predominant sensitizing allergen in early childhood, followed by tree pollen in later years. Sensitization patterns were similar between symptomatic and asymptomatic children, although symptomatic children exhibited higher frequencies and values. The sensitization profiles in very young children were comparable to those of children across all age groups.
These findings highlight the presence of sensitization to inhalant allergen components and the early onset of allergic rhinitis before the age of 4, including infancy, in Dutch atopic children. Notable allergen molecules in Dutch atopic children under the age of 4 years include Bet v 1, Fel d 1, Der f 1, Der p 1, Der p 10 and Phl p 4, with house dust mite sensitization being the most common among Dutch infants. Moreover, the prevalence of sensitization to inhalant allergens in this Dutch cohort surpassed that of general European populations, emphasizing the importance of early assessment and management of allergic rhinitis in young atopic children.
The introduction of baked milk products in cow's milk (CM) allergic children has previously been shown to accelerate induction tolerance in a selected group of children. However, there is no ...standardized baked milk product on the market. Recently, a new standardized, heated and glycated cow's milk protein (HP) product was developed. The aim of this study was to measure safety and tolerability of a new, well characterized heated CM protein (HP) product in cow's milk allergic (CMA) children between the age of 3 and 36 months. The children were recruited from seven clinics throughout The Netherlands. The HP product was introduced in six incremental doses under clinical supervision. Symptoms were registered after introduction of the HP product. Several questionnaires were filled out by parents of the children. Skin prick tests were performed with CM and HP product, sIgE to CM and α-lactalbumin (Bos d4), β-lactoglobulin (Bos d5), serum albumin (Bos d 6), lactoferrin (Bos d7) and casein (Bos d8). Whereas 72% percent (18 out of 25) of the children tolerated the HP product, seven children experienced adverse events. Risk factors for intolerance to the HP product were higher skin prick test (SPT) histamine equivalent index (HEP) results with CM and the HP product, higher specific IgE levels against Bos d4 and Bos d8 levels and Bos d5 levels. In conclusion, the HP product was tolerated by 72% of the CM allergic children. Outcomes of SPT with CM and the HP product, as well as values of sIgE against caseins, α-lactalbumin, and β-lactoglobulin may predict the tolerability of the HP product. Larger studies are needed to confirm these conclusions.
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