Feature Papers 2023

Pollen food allergy syndrome (PFAS) is an allergic reaction to specific foods in persons previously sensitised to pollen. The diagnosis of PFAS is made after taking a patient’s medical history and, in some cases, conducting skin tests and oral food tests with raw fruit or vegetables. The aim of the present study was to evaluate the role of Pru p 7 in patients suspected of having PFAS, who show clinical symptoms, positivity for Cup a 1 and negativity for Pru p 1 and Pru p 3. A total of 51 patients (mean age ± standard deviation, 33 ± 15 years; 20 men and 31 women), referred to the respiratory diseases and allergology units of Siena University Hospital, were enrolled retrospectively. All of them underwent allergy consultation and IgE evaluation for Cup a 1, Pru p 1 and Pru p 3 by immuno solid-phase allergen chip (ISAC). Pru p 7 assay was performed by the ImmunoCAP Phadia method in patients who tested positive for Cup a 1 and simultaneously negative for Pru p 1 and Pru p 3 by ISAC. The serum of 51 patients was tested for sensitisation to Pru p 7 by the ImmunoCAP Phadia method, and nine patients (17.65%) were found positive. An area under the receiver operating characteristic (AUROC) curve of 99.51% made it possible to distinguish PFAS and non-PFAS patients on the basis of Pru p 7 values. The best cut-off value was 0.16 kUA/l, which gave a 85.7% sensitivity and 97.73% specificity. This study helps define the role of Pru p 7 in PFAS patients sensitised to cypress pollen and testing negative to Pru p 1 and Pru p 3. A fast, easy and non-invasive diagnostic method is proposed to detect IgE specific for Pru p 7. Inclusion of Pru p 7 in the ISAC assay panel would facilitate the diagnosis of PFAS. Full article

Adrenaline auto injectors (AAI) are the mainstay of treatment in anaphylaxis. However, many caregivers of children with food allergies are unable to administer an AAI when assessed. One proposed factor for this finding is the lack of training and familiarity of the different AAI devices. The aim of this study is to explore the usage of different brands of adrenaline auto-injectors among caregivers of children with food allergies in Ireland. A cross-sectional study method was employed using an online questionnaire. An amount of 121 (75.58%) caregivers reported that their child carried an Epipen^®, 25 (15.82%) carried Jext^®, and 12 (7.59%) carried Anapen^®. An amount of 48.73% (n = 77) of caregivers had switched brands of AAI at least once before, with lack of availability of their usual device at their pharmacy being the most common reason for this. Factors associated with change were a household income >100,000 € (70% vs. 44.9% of those with less income; p = 0.04) and parents ≥40 years old (59.6% vs. 32.8% of patients whose parents younger; p < 0.01). When asked what they preferred about a particular AAI brand, caregivers appreciated a simple design with minimal steps involved in administration, clear colour coding, online resources, formal training from a healthcare professional, and first-hand experience in using the AAI. These findings show, for the first time, that switching brands is a common occurrence among caregivers of children with food allergies. These findings support the EAACI recommendation to train parents regularly in all available brands of AAI and to retrain parents when switching to different devices. Full article

The treatment of allergic conditions presents a challenge for both seasonal allergic rhinitis and perennial rhinitis sufferers. The increasing prevalence of both of these types of allergic responses requires the use of a range of treatments which can provide relief. The treatment of allergic rhinitis has been considered under the ARIA (Allergic Rhinitis and its Impact on Asthma) guidelines. Current treatment options include medication and avoidance for those with reduced responses, but more expensive treatments include immunotherapy and the use of monoclonal antibodies (mAb). All treatments target specific parts of the inflammatory response which includes mast cells, eosinophils and basophils. Phototherapy can be a useful addition to these treatments, and combinations of UV-B (5%), UV-A (25%) and visible light (70%) in phototherapy treatments have been shown to reduce the severity of symptoms. Phototherapy consisting of visible wavelengths and infrared light (660 nm 940 nm) was shown to be particularly effective in treating perennial rhinitis. The use of a range of wavelengths in the control of allergic responses is described in this paper. Phototherapy can form part of an effective treatment regime for allergic rhinitis sufferers which can exploit synergies in the control of the condition elicited through several pathways. Full article

Allergens are substances that cause abnormal immune responses and can originate from various sources. IgE-mediated allergies are one of the most common and severe types of allergies, affecting more than 20% of the population in Western countries. Allergens can be subdivided into a limited number of families based on their structure, but this does not necessarily indicate the origin or the route of administration of the allergen, nor is the molecular basis of allergenicity clearly understood. This review examines how understanding the allergenicity of proteins involves their structural characterization and elucidates the study of conformational diversity by nuclear magnetic resonance spectroscopy. This article also discusses allergen cross-reactivity and the mechanisms by which IgE antibodies recognize and bind to allergens based on their conformational and linear epitopes. In addition, we outline how the pH, the proteolytic susceptibility and the endosomal degradation affect the outcome of allergic reactions, and how this is correlated with conformational changes and secondary structure rearrangement events. We want to emphasize the importance of considering structural diversity and dynamics, proteolytic susceptibility and pH-dependent factors to fully comprehend allergenicity. Full article