Diagnosis Of Allergy Research Articles

IgE response to Aed al 13 and Aed al 14 recombinant allergens from Aedes albopictus saliva in humans

BackgroundMosquito bite is normally associated with mild allergic responses, but severe localized or systemic reactions are also possible. Reliable tools for the diagnosis of mosquito allergy are still unavailable. Here, we investigated the IgE response to 3 potential salivary allergens identified in the saliva of the tiger mosquito Aedes albopictus. MethodsSerum from 55 adult individuals (28 controls and 27 allergic people), were analysed using an in-house Enzyme Linked ImmunoSorbent Assay (ELISA) against the Salivary Gland Extract (SGE) and the recombinant proteins albD7l2 (Aed al 2), albAntigen5-3 (Aed al 13) and albLIPS-2 (Aed al 14). ResultsFifteen of the 27 (56%) individuals having hypersensitive reactions to mosquito bites had IgE serum levels recognizing SGE. Negative sera did not show detectable levels of IgE targeting the SGE from the most common sympatric mosquito Culex pipiens. Among the positive individuals, 2 subjects displayed IgE targeting Aed al 2 (13%), while IgE recognizing Aed al 13 and Aed al 14 were detected in ten (67%) and seven (47%) individuals, respectively. Two sera from non-hypersensitive subjects had detectable levels of IgE targeting Aed al 13, suggesting possible cross-reaction with the homologue salivary proteins of multiple mosquito species or, more generally, of hematophagous insects. ConclusionsOur results indicate that Aed al 13 and Aed al 14 hold the potential to be developed as tools for the diagnosis of allergy to Ae. albopictus bites. Such tools would facilitate epidemiological studies on tiger mosquito allergy in humans and might foster the development of further protein-based assays to investigate cross-species allergies.

Delabeling, safety, and impact of β-lactam allergy testing: Asystematic review.

To improve β-lactam delabeling outcomes, we need to understand current practice and the evidence base regarding its outcomes, safety, and impact. We sought to assess the existing published evidence reporting on the effectiveness of penicillin allergy testing and delabeling. We conducted a systematic review of studies reporting β-lactam delabeling practices and outcomes after testing, including β-lactam use and patient understanding of the delabeling result. Searches of the PubMed, Scopus, and Embase databases; clinical trial registries; and websites of professional organizations were conducted. Data were extracted from the included studies in duplicate, with a third extraction if discrepancies remained. We included 284 publications (covering 98,316 participants); 173 were prospective studies, with no randomized controlled trials. The overall study quality was low. In all, 95.6% of individuals who underwent provocation testing were delabeled. Factors associated with successful delabeling could not be determined because of significant heterogeneity between studies. Anaphylaxis due to testing occurred in 0.3% of participants (95 of 31,667). Subjects who did not undergo skin testing (6,980 patients in 31 studies) before challenge had higher rates of provocation test positivity (8.8% vs 4.1% [P< .0001]) and anaphylaxis (15.9% vs 2.7% [P< .0001]) than those subjects who underwent skin testing (51,607 patients in 177 studies). Six studies (2.1%) followed patients after testing to assess their adherence to prescribing recommendations. In all, 136 participants (20.6%) were actively avoiding β-lactams despite delabeling. The available data suggest that penicillin allergy testing is safe and effective in delabeling most individuals, but the evidence base is incomplete and more work is required to assess the role of skin testing and the impact that delabeling is having on prescribing habits.

Immunoglobulin E–Mediated Food Allergies

This second article on food allergies focuses on food allergic reactions involving specific immunoglobulin E (IgE) mechanism within the immune system. An IgE-mediated food allergy diagnosis requires both the sensitization (positive test) and the clinical signs and symptoms consistent with IgE-mediated food allergy response. Having the confirmed diagnosis and management plan is crucial because the signs and symptoms appear rapidly after every ingestion of a food with the potential to progress in severity to a life-threatening situation, anaphylaxis. A clear understanding of what constitutes a food allergy, specifically an IgE-mediated food allergy, will facilitate clear communication among healthcare professionals, patients and caregivers, and those in the public.

Penicillin allergy de-labelling by non-allergists: a comparison of testing protocols.

Optimizing penicillin allergy de-labelling (PADL) to ensure patients with an incorrect penicillin allergy record are de-labelled with minimal patient harm is important for antibiotic stewardship. The heterogeneity of inclusion and exclusion criteria in the published penicillin allergy testing protocols risks suboptimal delivery of PADL. We compared the similarities and the differences between non-allergist-delivered PADL testing protocols and make suggestions for harmonization. The observed variation in testing practice has two broad elements: (i) definitions and terminology; and (ii) differences in the acceptability of perceived risk. All direct drug provocation testing (DDPT) protocols included patients with benign delayed rash as eligible for testing, although the remoteness of the rash, and the terminology used to describe the rash, differed. Patients with features of potential IgE reactions were excluded from most DDPT protocols, but not all of them. There was differing advice on how to manage patients who had subsequently tolerated penicillin since the index reaction and differences in which patients were considered ineligible for DDPT due to acuity of illness, comorbidities and concomitant medications. Standardization of the terminology used in penicillin allergy testing protocols and consensus on inclusion and exclusion criteria are required for safe and efficient PADL delivery at scale by non-allergists.

The role of major and minor determinants in penicillin allergy testing: Time to revisit an old friend?

Skin testing is an important step in evaluation of penicillin allergic reactions. It includes testing to the following: amoxicillin, benzyl penicillin, and products generated invivo after penicillin administration, the major determinant hapten penicilloyl-polylysine (PPL) and the minor determinant mixture (MDM). Although PPL and MDM are available as a commercial kit, their supply and cost remain problematic. We aimed to evaluate the performance and utility of PPL and MDM in penicillin allergy testing. A retrospective audit over a 5-year period was undertaken for those with penicillin testing in a tertiary immunology unit. In all, 214 patients were identified. Of those patients, 151 (70.6%) were female and the average age was 58 years. Unspecified penicillin was the most common index drug (n=127 [59.3%]), followed by amoxicillin (n=3 [24.8%]) and amoxicillin-clavulanic acid (n= 21 [9.7%]). The result of skin testing was positive in 23 patients (10.7%); skin prick testing was positive in 10 patients (4.7%), and intradermal testing (IDT) was positive in 13 patients (6.1%), the majority of whom had identified amoxicillin or amoxicillin-clavulanic acid as the index drug (n= 22 [95.7%]). The result of testing to PPL and/or MDM was positive with IDT only (n=5 [23.8%]). PPL and MDM positivity coexisted with a positive reaction to amoxicillin IDT in 2 patients, 1 of whom passed an amoxicillin challenge. Additionally, 2 positive tests to PPL were present with a negative result for MDM; of these 2 positive results, 1 was positive to amoxicillin IDT. In only 1 case were the results of testing for MDM and PPL both positive, with negative results to all native β-lactams tested; the patient tolerated an amoxicillin challenge. Overall, the negative predictive value for both skin prick testing and IDT was 89.5%. Benzyl penicillin and amoxicillin alone may be sufficient for invivo testing in suspected individuals with penicillin allergy.

Shellfish allergy – diagnostic approach

Shellfish allergy is one of the most common food allergies, with an estimated prevalence of 3% in the general population. Crustaceans and mollusks are part of this food category, being capable of immunologic hypersensitivity reactions (IgE-mediated, as well as non-IgE-mediated), but also non-immunologic reactions, based on intoxication with certain neurotoxins from contaminated seafood, in which neurological but also gastrointestinal symptoms predominate. The clinical picture in IgE-mediated hypersensitivity reactions can vary in severity, from mild reactions such as oral allergy syndrome to severe reactions such as anaphylaxis. Among the delayed, non-IgE mediated reactions, we can identify food protein-induced enterocolitis syndrome, food protein-induced enteropathy and food protein-induced allergic proctocolitis, which mainly involve gastrointestinal symptoms. Over the past decades, the knowledge gained regarding the characteristics of different allergens has improved the diagnostic approach. Thus, for an accurate diagnosis of seafood-induced allergy, a thorough history, along with skin prick testing and specific IgE dosing are essential, and when these are insufficient, an oral challenge test can disentangle causality.

Pork-cat syndrome

Meat allergy used to be considered a rare hypersensitivity reaction, but case reports of mammalian and poultry meat allergies became more common about 20 years ago. Allergies to pets such as cats (Felis domesticus) and dogs (Canis familiaris) are the second most common indoor allergic reactions in Western countries, affecting both adults and children. An important step in fur allergy diagnosis has been the introduction of molecular allergen-based diagnosis, which offers new opportunities for improved allergen characterization. An example of these new characterizations is the meat reactions of patients suffering from pork-cat syndrome. Patients with this syndrome sensitized to albumin from animal epithelia report symptoms after eating pork because there is cross-reactivity to albumins from different species. The management of a patient with an allergic condition to fur-bearing animals includes a detailed history of exposure to relevant allergens, the effect of exposure on symptoms and subsequent recommendations for controlled exposure, and in the case of pig-cat syndrome, the patient can tolerate well-cooked red meat, but not the insufficiently prepared one.

Case Report: Allergic Rhinitis

Case #1 A 32-year-old female presents to her primary healthcare professional (HCP) with a long history of intermittent nasal congestion, sneezing, rhinorrhea, and itchy eyes. She recalls experiencing these symptoms in high school, but notes that her condition has worsened over the years. Her symptoms were previously present only in the summer; however, they now extend year-round. She reports that her symptoms affect her sleep when she has complete nasal blockage, that she is forced to blow her nose throughout the night, and that the constant wakening leaves her feeling fatigued. She notes that she has “tried everything” in terms of over-the-counter (OTC) medications and that she finds the side effects bothersome. She is requesting allergy testing and has heard that there is “a shot” available.

Severity predictors of different phenotypes of T2 asthma endotype

BACKGROUND: Epidemiological studies have showed that severe asthma is observed in 5–10% of patients. It is considered as a major social and economic burden for the healthcare system.&#x0D; AIM: to perform a comparative analysis of clinical features of allergic and non-allergic phenotypes of T2 asthma and determine the most important predictors of severity.&#x0D; MATERIALS AND METHODS: We studied 150 patients with asthma (ages 18–65). Of these, 61 were diagnosed with T2 endotype of asthma. Clinical examination and allergy testing were performed. The potential predictors of severe asthma included: asthma phenotype, gender, age (including elderly age), daytime/nocturnal symptoms per week, asthma exacerbations that required systemic corticosteroid therapy and hospitalisations, the volume of forced exhalation in the first second (FEV1; % of predicted value), body mass index (kg/m2), concomitant diseases, smoking status, sensitization to non-infectious allergens and blood eosinophil count.&#x0D; RESULTS: Group 1 included 34 patients with allergic phenotype of asthma, group 2 ― 27 patients with non-allergic phenotype of T2 endotype of asthma. Univariate analyses revealed that subjects with non-allergic asthma were likely to have severe asthma (OR=3.14 [95% CI: 1.09–9.58]. Increased daytime symptoms per week, nocturnal symptoms per week, exacerbations that require systemic corticosteroids and hospitalisation were associated with asthma severity (OR=1.05 [95% CI: 1.01–1.11], 1.21 [95% CI: 1.05–1.45], 3.46 [95% CI: 1.68–10.19], 4 [95% CI: 1.75–12.32] and 4 [95% CI: 1.75–12.32], respectively), regardless of the disease phenotype. Lower FEV1 was associated with severe asthma (OR=0.96 [95% CI: 0.93–0.99]. Multivariate analysis showed that age, increased frequency of nocturnal symptoms, and lower FEV1 were associated with severe asthma.&#x0D; CONCLUSION: The certain clinical differences of allergic and non-allergic asthma could be revealed when analyzing anamnestic data and clinical findings. Increased frequency of nocturnal symptoms, decreased FEV1 and age are the most significant predictors of severe T2 endotype of asthma.

To be or not to be for a diet? Decision-making algorithm for dietary management of children with atopic dermatitis

The widespread, and not always justified, long-term prescription of a hypoallergenic diet for atopic dermatitis without allergy testing and verification of the diagnosis of food allergy has led to the pendulum swinging in the opposite direction: in recent years, the effectiveness and necessity of an elimination diet in therapy atopic dermatitis is frequently questioned. At the same time, it is generally accepted that in proven food allergy, the targeted elimination diet remains a necessary method in complex therapy.&#x0D; A study was conducted, including a retrospective analysis of 430 case histories and an examination of 130 children with severe atopic dermatitis as part of the prospective part of the study. The analysis of the nutritional status, chemical composition of the diet, body composition, quality of life, eating behavior, as well as compliance of the patients parents was carried out which made it possible to analyze the complex interaction of these indicators with various factors as well as with each other. Risk factors for impaired nutritional status and eating behavior in children with severe atopic dermatitis were early onset of the disease, and long-term adherence to recommendations for limiting or excluding various foods from the diet, especially dairy and/or 4 or more food groups. It was revealed that it is an unbalanced diet, and not elimination itself, is the main factor that reduces the nutritional status of a child. Additional risk factors for impaired nutritional status are the traits of childrens eating behavior caused by the disease itself and adherence to dietary measures, making it difficult to form a complete diet if a diet is necessary and to expand it. As a result, an algorithm was formed, aimed at optimizing the nutritional support of children suffering from atopic dermatitis and food allergy.

Clinical management of plant food allergy in patients sensitized to lipid transfer proteins is heterogeneous: identifying the gaps.

Patients sensitized to lipid transfer protein (LTP) present a wide clinical variability. The lack of practical diagnostic and therapeutic guidelines complicate their management. The aim of the study was to describe the clinical approach of Spanish allergists to this pathology using a survey designed by PICO method and subsequent Delphi approach validation. Designed survey was answered by 224 allergists (75% women; 57.1% with >20 years of professional experience). Homogeneity regarding clinical practice on the main points of LTP allergy diagnosis was observed, except for patients with suspected NSAID hypersensitivity (44.6% frequently include LTP skin testing). Oral food challenges were not frequently performed (63.6% occasionally to never), and they were generally (75.5%) used to confirm tolerance. It was common to recommend fruit skins avoidance (77.2%) and maintaining consumption of foods to which patients are sensitised but tolerant (99.1%). There was heterogeneity on other dietary indications, modifications due to co-factors, or traces avoidance. Peach sublingual immunotherapy (SLIT) was considered very/quite effective by 55.9% of allergists. The majority (79.5%) consider SLIT indicated in <25% of LTP allergic patients, based on severity (95.2%), frequency of reactions (99.4%), allergy to multiple food families (97.4%), and the quality of life/nutrition impairment (91.5%). There was different practice on SLIT prescription based on co-factor involvement. These data suggest that there is a need to increase evidence to reduce the clinical practice heterogeneity in the management of LTP allergy.

Unique allergen-specific human IgE monoclonal antibodies derived from patients with allergic disease.

Allergic reactions are mediated by human IgE antibodies that bind to and cross-link allergen molecules. The sites on allergens that are recognized by IgE antibodies have been difficult to investigate because of the paucity of IgE antibodies in a human serum. Here, we report the production of unique human IgE monoclonal antibodies to major inhaled allergens and food allergens that can be produced at scale in perpetuity. The IgE antibodies were derived from peripheral blood mononuclear cells of symptomatic allergic patients, mostly children aged 3-18 years, using hybridoma fusion technology. Total IgE and allergen-specific IgE was measured by ImmunoCAP. Their specificity was confirmed through ELISA and immunoblotting. Allergenic potency measurements were determined by ImmunoCAP inhibition. Biological activity was determined in vitro by comparing β-hexosaminidase release from a humanized rat basophilic cell line. Human IgE monoclonal antibodies (n = 33) were derived from 17 allergic patients with symptoms of allergic rhinitis, asthma, atopic dermatitis, food allergy, eosinophilic esophagitis, or red meat allergy. The antibodies were specific for five inhaled allergens, nine food allergens, and alpha-gal and had high levels of IgE (53,450-1,702,500 kU/L) with ratios of specific IgE to total IgE ranging from <0.01 to 1.39. Sigmoidal allergen binding curves were obtained through ELISA, with low limits of detection (<1 kU/L). Allergen specificity was confirmed through immunoblotting. Pairs of IgE monoclonal antibodies to Ara h 6 were identified that cross-linked after allergen stimulation and induced release of significant levels of β-hexosaminidase (35%-80%) from a humanized rat basophilic cell line. Human IgE monoclonal antibodies are unique antibody molecules with potential applications in allergy diagnosis, allergen standardization, and identification of allergenic epitopes for the development of allergy therapeutics. The IgE antibody probes will enable the unequivocal localization and validation of allergenic epitopes.

EAACI guidelines on the diagnosis of IgE-mediated food allergy.

This European Academy of Allergy and Clinical Immunology guideline provides recommendations for diagnosing IgE-mediated food allergy and was developed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Food allergy diagnosis starts with an allergy-focused clinical history followed by tests to determine IgE sensitization, such as serum allergen-specific IgE (sIgE) and skin prick test (SPT), and the basophil activation test (BAT), if available. Evidence for IgE sensitization should be sought for any suspected foods. The diagnosis of allergy to some foods, such as peanut and cashew nut, is well supported by SPT and serum sIgE, whereas there are less data and the performance of these tests is poorer for other foods, such as wheat and soya. The measurement of sIgE to allergen components such as Ara h 2 from peanut, Cor a 14 from hazelnut and Ana o 3 from cashew can be useful to further support the diagnosis, especially in pollen-sensitized individuals. BAT to peanut and sesame can be used additionally. The reference standard for food allergy diagnosis is the oral food challenge (OFC). OFC should be performed in equivocal cases. For practical reasons, open challenges are suitable in most cases. Reassessment of food allergic children with allergy tests and/or OFCs periodically over time will enable reintroduction of food into the diet in the case of spontaneous acquisition of oral tolerance.

Dermal tissue penetration of in-plane silicon microneedles evaluated in skin-simulating hydrogel, rat skin and porcine skin

Recently, microneedle-based sensors have been introduced as novel strategy for in situ monitoring of biomarkers in the skin. Here, in-plane silicon microneedles with different dimensions and shapes are fabricated and their ability to penetrate skin is evaluated. Arrays with flat, triangular, hypodermic, lancet and pencil-shaped microneedles, with lengths of 500–1000 μm, widths of 200–400 μm and thickness of 180–500 μm are considered. Fracture force is higher than 20 N for all microneedle arrays (MNA) confirming a high mechanical stability of the microneedles. Penetration force in skin-simulating hydrogels, excised rat abdominal skin and porcine ear skin is at least five times lower than the fracture force for all MNA designs. The lowest force for skin penetration is required for triangular microneedles with a low width and thickness. Skin tissue staining and histological analysis of rat abdominal skin and porcine ear skin confirm successful penetration of the epidermis for all MNA designs. However, the penetration depth is between 100 and 300 μm, which is considerably lower than the microneedle length. Tissue damage estimated by visual analysis of the penetration hole is smallest for triangular microneedles. Penetration ability and tissue damage are compared to the skin prick test (SPT) needle applied in allergy testing.

Clinical factors influencing olfactory performance in patients with persistent COVID-19 smell loss longer than 1 year.

Factors affecting persistence of COVID-19-related olfactory dysfunction (OD) remain partially unknown. We aim to evaluate the clinical factors which could influence olfactory performance in patients with persistent COVID-19-related smell loss. A retrospective analysis of 100 patients with persistent COVID-19-related OD was performed between October 2020 and December 2022 at a single-center long-COVID smell clinic. All subjects underwent smell assessment using Sniffin' Sticks (S'S) extended test, nasal endoscopy, nasal airflow evaluation (peak nasal inspiratory flow [PNIF]), allergy test (skin prick test [SPT]) for common aeroallergens, MRI of the head and patient-reported outcome measures (PROMs-VAS, SF-36, Short QOD-NS, SNOT-22). Based on S'S score, subjects were divided into normosmics (TDI ≥ 30.75) and dysosmics (TDI < 30.75). The median age was 42 years and the median length of patient-reported OD was 1.4 years. 20 patients (20.0%) were normosmic at the time of S'S assessment. Dysosmic patients were found to have significantly lower scores at the SF-36 health domains for energy/fatigue (p = .0004) and emotional wellbeing (p = .04) when compared to normosmics. A moderate correlation (r = .45-.59) between S'S scores and some PROMs was also demonstrated. At the multivariate analysis higher PNIF scores positively influenced odor threshold (p = .001) while positivity to SPT negatively influenced odor identification (p = .04). Impairment of nasal airflow and sensitivity to aeroallergens can negatively affect olfactory performance in COVID-19-related OD. Long-COVID smell loss deeply affects QoL although recovery of olfaction can bring it back to a normal range. IV.

The results of a survey of Russian doctors in order to identify the compliance of the management of children with chronic urticaria with clinical recommendations

Introduction. Primary observation of children with (CU) in Russia is performed by pediatricians, dermatologists, and algologists. It is unclear how clinical guidelines are used in a heterogeneous group of specialists.Materials and methods. Online survey of pediatricians, allergists, and dermatologists (n = 304) in the Russian Federation using a questionnaire, from 5 blocks of questions related to etiology, diagnosis, and therapy. 316 physicians with a median experience of 10 [5; 20] years were included in the questionnaire.Results. 83.3 % of respondents observed no more than 2 children with CU per month. Self-education to expand knowledge (video lectures, special literature) was indicated by 72.6 % of participants. The clinical guidelines used by physicians were documents of pediatric and allergy associations of Russia (77.3 and 55.9 %, respectively), international guides were used by 27 % of respondents.The most frequent deviations from the recommended algorithm were the prescription of biochemical blood tests (64.9 %), ultrasound examination of organs (56.9 %), consultations of specialists without indications: gastroenterologist (48.2 %), infectious disease specialist (31.8 %), rheumatologist (27.1 %). The autologous serum test in children is not used by 87.2 % of physicians for various reasons.During allergy testing, respondents recommend: the concentration of total IgE in serum (63.9 %), the number of eosinophils in the blood (61.2 %). The importance of determining specific IgE was indicated by no more than one third of the respondents. Skin tests during remission period were supported by 59.1 % of all physicians, who considered allergologic examination to be necessary. Diet: 18.6 % of respondents do not recommend a special diet for children; 27.7 % exclude from the diet foods to which sensitization is detected, the rest recommend an nonspecific elimination diet.Antihistamines of 2nd generation (AG II) are the most used in clinical practice (86.5 %). Physicians named cetirizine (25.7 %) and levocetirizine (19.7 %) as the drugs of choice up to 12 years of age. The need to double the dose of AG II in the absence of response to the standard dose was supported by 59.5 % of physicians. The other physicians preferred a change of AG II molecule in the standard dose. Experience with the use of omalizumab was reported by 20 % of specialists, with 76.3 % understanding the significance and willingness to use biologic therapy. If omalizumab is ineffective, 44.1 % of physicians consider glucocorticosteroids to be the drug of choice; 38.8 % — cyclosporine A. About one third of physicians use alternative therapies not considered in the clinical guidelines.Conclusion. A significant number of physicians do not use recommendations based on evidence-based studies in real practice. AG II are the basis of CU therapy in children in all age groups.

Molecular characterization of Clostridium perfringens isolates from a tertiary children’s hospital in Guangzhou, China, establishing an association between bacterial colonization and food allergies in infants

BackgroundCow’s milk protein allergy (CMPA) is one of the most common types of food allergy in infants. Faecal pathogen cultures showed that the positive rate of Clostridium perfringens was more than 30%, which was significantly higher than that for other bacteria. Therefore, it is speculated that Clostridium perfringens colonization may be one of the pathogenetic factors for CMPA in infants. We conducted a real-world evidence study. Infants aged 0–6 months with diarrhoea and mucoid and/or bloody stools were recruited from a large tertiary hospital in China. Faecal pathogen cultures for the detection of Clostridium perfringens were confirmed by flight mass spectrometry, and potential toxin genes were identified using PCR. After 12 months of follow-up, the diagnoses of CMPA and food allergy were recorded. The correlation was assessed by Pearson correlation analysis.ResultsIn this study, 358 infants aged 0–6 months with gastrointestinal symptoms and faecal pathogen cultures were recruited. A total of 270 (44.07% girls; mean age, 2.78 ± 2.84 months) infants were followed up for 12 months. Overall, the rate of positivity for Clostridium perfringens in faecal pathogen cultures was 35.75% (128/358) in infants aged ≤ 6 months. The earliest Clostridium perfringens colonization was detected within 2 days after birth. The majority of Clostridium perfringens isolates were classified as type C in 85 stool samples. In the Clostridium perfringens-positive group, 48.21% (54/112) of infants were clinically diagnosed with food allergies after 12 months, including 37.5% (42/112) with CMPA, which was significantly higher than that of the negative group, with 7.59% (12/158) exhibiting food allergies and 5.06% (8/158) presenting CMPA (P < 0.0001). Faecal Clostridium perfringens positivity was significantly correlated with CMPA, food allergy, faecal occult blood, faecal white blood cells, antibiotic use, increased peripheral blood platelet counts, and decreased haemoglobin levels (P < 0.0001).ConclusionsThis study demonstrates that intestinal colonization by Clostridium perfringens is common in infants. The majority of Clostridium perfringens isolates are classified as type C. Colonization of the intestine by Clostridium perfringens is associated with the development of CMPA and food allergy in infants.

SAT334 Hypoxic Reduction Of Adrenal Steroidogenesis- The Cause Of Idiopathic Allergic Reactions

Abstract Disclosure: S. Kalinchenko: None. L. Vorslov: None. D. Gusakova: None. O. Samburskaya: None. Hypoxic reduction of adrenal steroidogenesis - The Cause of Idiopathic Allergic Reactions Background: This thesis discusses the occurrence of idiopathic allergic reactions, with an established absence of allergy to any trigger by allergo-tests, with the sole presence of a history of decompensated chronic stress, which led to a stress-induced decrease in adrenal steroidogenesis called “adrenal fatigue” with decreased production of the main anti-inflammatory, anti-allergic and stress hormone, cortisol. Materials and methods: The study included 10 patients aged 20 to 55 years, 8 women and 2 men, diagnosed with idiopathic allergic reactions (urticaria, toxidermia, erythema multiforme exudative, Quincke's edema). All patients were examined for steroid hormone levels using a steroid profile in saliva by mass spectrometry and performing allergy tests (to identify a possible allergen). Findings: From the anamnesis, all 10 patients had long-term chronic stress, which was already in the stage of decompensation, and according to the Beck depression scale, 8 patients showed mild (11-17 points) and medium (18-23 points) severity of depression in 2 patients. In the steroid profile of saliva in all 10 patients, a decrease below 07\ры the reference level of cortisol (700-2200 pg/ml) and cortisone (27400-39200 pg/ml) was found. After relief of acute symptoms by corticosteroids, all patients were prescribed infusion therapy with ascorbic acid at a dosage of 1,000 mg three times a week for three weeks to stimulate the adrenal glands. As a result, repeated analysis of the steroid profile of saliva showed an increase in the level of cortisol and cortisone within the reference values.Allergotests are negative for all known allergens. Interpretation: As is known, allergens play a primary role in the development of diseases such as urticaria, toxidermia, erythema multiforme, Quincke's edema. However, there are increasingly cases when it is not possible to establish the trigger that caused the development of an allergic reaction, and conducting allergy tests does not reveal the presence of allergen triggers in patients. However, these patients are united by a decrease in adrenal steroidogenesis against the background of decompensated chronic stress called “adrenal fatigue”, which manifests itself in a decrease in the level of cortisol and cortisone in the steroid profile of saliva below the reference values, which are the main anti-inflammatory, antiallergic hormones and hormones that are synthesized in response to stress, and with chronic stress, the reserves of these hormones are depleted, which provokes the development of inflammatory and allergic reactions in response to ordinary stimuli. Conclusion: Stimulation of the adrenal glands with reduced steroidogenesis is an opportunity to reduce the risk of inflammatory and allergic reactions in patients with decompensated chronic stress. Presentation: Saturday, June 17, 2023

Back to basics: likelihood ratios for olive and grass pollen specific IgE in seasonal allergic rhinitis.

Specific IgE (sIgE) is merely a sensitization marker that cannot be used for allergy diagnosis if there are no associated clinical symptoms. As of 2023, there is still no evidence regarding the quantity of sIgE necessary to confirm or exclude clinical disease. Therefore, this study aimed to calculate cut-offs for sIgE, allowing us to effectively diagnose olive or grass pollen allergy and select allergenic immunotherapy (AIT) candidate patients in a region under high olive and grass allergenic pressure. An observational retrospective study consisting of the review of electronic medical records from 1,172 patients diagnosed with seasonal rhino-conjunctivitis and suspected allergy to olive or grass pollen. Symptoms correlated with sIgE to Poaceae and Oleaceae whole extracts and sIgE to genuine allergenic components were evaluated. Optimal cut-off values were calculated using receiver operating characteristic curves. Relevant clinical symptoms and AIT indications were taken into consideration when determining the clinical allergy diagnosis. sIgE to Lolium showed the best area under the curve (AUC) for both diagnosis (0.957) and an indication of AIT (0.872). The optimal cut-off values for grass diagnosis and AIT indication were 1.79 kUA/L and 8.83 kUA/L, respectively. A value of 5.62 kUA/L was associated with a positive likelihood ratio (LR) of 10.08 set for grass allergy. Olea sIgE showed the best AUC for the diagnosis (0.950). The optimal cut-off for diagnosis was 2.41 kUA/L. A value of 6.49 kUA/L was associated with a positive LR of 9.98 to confirm olive pollen allergy. In regard to immunotherapy, Ole e 1 sIgE showed the best AUC (0.860). The optimal cut-off was 14.05 kUA/L. Ole e 1 sIgE value of 4.8 kUA/L was associated with a 0.09 negative LR to exclude olive AIT indication. The sIgE cut-offs found in this population under high olive and grass allergenic pressure reduce the gap between sensitization and clinical allergy, providing a new tool for the diagnosis of seasonal allergic rhinitis/asthma and helping to discriminate patients who will benefit from AIT.

History and Utility of Specific IgE Cutoff levels: What is the Relevance for Allergy Diagnosis?

Allergy is defined clinically, by symptoms on allergen exposure. A patient is considered sensitized when allergen-specific IgE (sIgE) antibody can be detected in serum or plasma or a skin test result is positive, even if no clinical reaction has been experienced. Sensitization should be regarded as a requisite and risk factor for allergy but is not synonymous with an allergy diagnosis. To provide a correct allergy diagnosis, test results regarding allergen-sIgE must always be considered in view of the patient's case history and clinical observations. Correct assessment of a patient's sensitization to specific allergens relies on the use of accurate and quantitative methods for detection of sIgE antibodies. The evolution of sIgE immunoassays toward higher analytical performance and the use of different cutoff levels in the interpretation of test results sometimes cause confusion. Earlier versions of sIgE assays offered a limit of quantitation of 0.35 kilounits of sIgE per liter (kUA/L), which also became an established cutoff level for a positive test result in the clinical use of the assays. Current sIgE assays are capable of reliably measuring sIgE levels as low as 0.1 kUA/L and can thereby demonstrate sensitization in cases in which previous assays could not. When the outcome of sIgE test results is evaluated, it is critically important to distinguish between the analytical data as such and their clinical interpretation. Even though sIgE may be present in the absence of symptoms of allergy, available information suggests that sIgE concentrations between 0.1 kUA/L and 0.35 kUA/L may be clinically relevant in some individuals, not least among children, although this should be further evaluated for various allergies. Moreover, it is becoming widely adopted that nondichotomous interpretation of sIgE levels may offer a diagnostic benefit compared with using a predefined cutoff level.