Effects of thermal treatment on walnut detection and allergenicity.

BACKGROUND: Peanuts and tree nut allergies pose an increasing food safety problem. The aim of our study was to test the accuracy of different commercial enzyme-linked immunosorbent assay (ELISA) kits in the detection of the presence of walnuts in untreated and heat exposed food samples. The effects of thermal treatment of samples were evaluated by exposing walnuts to different heat treatments. All samples were first analysed by two different commercial ELISA assays. Then, we performed a skin prick test (SPT) on nine patients with proven nut allergy using small walnut pieces from raw and treated samples. RESULTS: The presence of nuts proteins in thermally processed foods was not accurately detected by ELISA kits. All patients had a positive SPT reaction with raw walnut, while thermal treatments affected walnut allergenicity. The ELISA test gives a negative result in the case of strong thermal treatment, but at the same time allergic subjects react positively to stimulation with the same sample. CONCLUSION: This study suggests that commercial ELISA kits may not be able to accurately determine the amount of proteins present in thermally processed foods due to changes in the solubility and immunoreactivity of the target proteins. Finally, the clinical results highlight that thermal treatment might induce a reduction in walnut allergenicity. © 2018 Society of Chemical Industry.

Birch allergy and oral allergy syndrome: The practical relevance of serum immunoglobulin E to Bet v 1.

BACKGROUND: Birch allergy (BA) may frequently be associated with fruit-vegetables oral allergy syndrome (OAS). Bet v 1 is the major birch allergen. Previously, it was reported that serum-specific immunoglobulin E (IgE) level could differentiate allergy from sensitization. Thus, this study aimed to investigate the practical role of Bet v 1 IgE. METHODS: A total of 245 subjects (128 women, 117 men; mean age, 41 years) with suspected allergic rhinitis and sensitization to Bet v 1 were evaluated. Serum IgE to Bet v 1 was assessed by using immuno-enzymatic. BA and OAS were diagnosed according to validated criteria. Symptom severity perception was measured by the visual analog scale. RESULTS: A total of 158 patients (64.5%) had BA. Patients with BA had higher serum Bet v 1 IgE levels than subjects who were sensitized (p < 0.0001). A cutoff value of 8.94 kUA/L predicted BA (area under the curve, 0.76; odds ratio, 6.18). Fifty-three patients with BA (33.5%) had OAS. Patients positive for OAS had higher Bet v 1 levels (p < 0.0001) and more-severe symptoms (p < 0.0001) than patients with BA and negative for OAS. A cutoff value of 17.4 kUA/L predicted OAS (area under the curve, 0.59; odds ratio, 3.19). CONCLUSIONS: The present study demonstrated that serum IgE levels to Bet v 1 could be a useful marker for differentiating between different birch pollen sensitization phenotypes.

The IgE repertoire in children and adolescents resolved at component level: a cross-sectional study.

BACKGROUND: It is well known that allergy evolves at clinical level from the birth to adulthood, and this has been clearly demonstrated also at a level of sensitization. However, little information is available on the evolution of the IgE repertoire directed to single allergenic components. In this cross-sectional, observational study, the evolution of the IgE repertoire was analysed at component level. METHODS: Serum samples from 901 allergic patients, stratified in 6 groups according to age, were analysed by ImmunoCAP ISAC, a microarray chip that allows to identify the presence of specific IgE towards 103 different allergen components. Total IgE were also evaluated. RESULTS: The behaviour of total IgE according to age strictly paralleled that of the sum of specific IgE directed to molecular components. As expected, food-related components (in particular those of milk and egg) were the most frequently recognized in the earliest ages, whereas specific IgE to plant allergens appeared invariably later. Nonetheless, IgE specific to mite components was the most represented in all age classes. Of note, specific IgE against cross-reacting allergens was virtually absent in the first years and tended to appear only after the age of 6. CONCLUSION: Despite this was not a study performed on a cohort of patients followed up from birth to adolescence, the molecular patterns of allergen recognition resulted modified according to age. These findings may support, at molecular level, the clinical features of the allergic march.

Hymenoptera venom allergy in outdoor workers: Occupational exposure, clinical features and effects of allergen immunotherapy.

OBJECTIVES: To describe (i) the clinical characteristics of workers, exposed to hymenoptera stings, with an ascertained diagnosis of Hymenoptera Venom Allergy (HVA), (ii) the specific role of occupational exposure, (iii) the effect of Venom Immunotherapy (VIT) in reducing the severity of allergic episodes in workers exposed to repeated stings of hymenoptera, and (iv) the management of the occupational consequences caused by allergic reactions due to hymenoptera stings. METHODS: Between 2000 and 2013 an observational study, including patients referred to the regional reference hospital of Liguria, Italy, with an ascertained diagnosis of HVA and treated with VIT, was performed. A structured questionnaire was administered to all patients to investigate the occupational features of allergic reactions. These were graded according to standard systems in patients at the first episode, and after re-stings, during VIT. RESULTS: One-hundred and 8four out of the 202 patients referred had a complete data set. In 32 (17.4%) patients, the allergic reaction occurred during work activities performed outdoor. Of these, 31.2% previously stung by hymenoptera at work, and receiving VIT, were re-stung during occupational activity. The grades of reaction developed under VIT treatment resulted clinically less severe than of those occurred at the first sting (p-value = 0.031). CONCLUSION: Our findings confirmed the clinical relevance of HVA, and described its occupational features in outdoor workers with sensitization, stressing the importance of an early identification and proper management of the professional categories recognized at high risk of hymenoptera stings. The Occupational Physician should be supported by other specialists to recommend appropriate diagnostic procedures and the prescription of VIT, which resulted an effective treatment for the prevention of episodes of severe reactions in workers with a proven HVA.

Can serum white birch (Betula verrucosa) pollen antigen (Bet v 1) immunoglobulin E measurement distinguish between sensitization and allergy?

BACKGROUND: In clinical practice, it is fundamental to distinguish between sensitization and allergy, mainly with respect to polysensitized patients. The aim of this study was to evaluate whether serum immunoglobulin E (IgE) to white birch (Betula verrucosa) pollen antigen (Bet v 1) assessment might be able to differentiate simple sensitization from true allergy. METHODS: In total, 197 subjects (100 females; mean age 44.9 years) with serum Bet v 1 IgE positivity and history of nasal symptoms were evaluated. Subjects were subdivided in 2 groups: allergic and sensitized. RESULTS: Allergic patients were 58.4% of the total; they had higher serum Bet v 1 IgE levels than sensitized subjects (p < 0.001). A serum IgE to Bet v 1 value >8.94 kilo units of allergen per liter (kUA/L) was able to differentiate between sensitization and allergy (area under the receiver operating characteristic curve [AUC] = 0.76; diagnostic odds ratio, ie, degree of agreement between health status and dichotomized IgE levels [DOR] = 6.5). Gender and season when the blood was drawn influenced IgE levels. CONCLUSION: Serum Bet v 1 IgE measurement may be able to differentiate sensitization from allergy in subjects with sensitization to Betulaceae pollen allergens. Thus, Bet v 1 IgE measurement should be considered a useful step in the management of patients with allergic rhinitis due to Betulaceae pollen allergens.

A nationwide survey of hereditary angioedema due to C1 inhibitor deficiency in Italy.

INTRODUCTION: Hereditary angioedema due to C1-inhibitor deficiency (C1-INH-HAE type I) or dysfunction (C1-INH-HAE type II) is a rare disease characterized by recurrent episodes of edema with an estimated frequency of 1:50,000 in the global population without racial or gender differences. In this study we present the results of a nationwide survey of C1-INH-HAE patients referring to 17 Italian centers, the Italian network for C1-INH-HAE, ITACA. METHODS: Italian patients diagnosed with C1-INH-HAE from 1973 to 2013 were included in the study. Diagnosis of C1-INH-HAE was based on family and/or personal history of recurrent angioedema without urticaria and on antigenic and/or functional C1-INH deficiency. RESULTS: 983 patients (53% female) from 376 unrelated families were included in this survey. Since 1973, 63 (6%) patients diagnosed with C1-INH-HAE died and data from 3 patients were missing when analysis was performed. Accordingly, the minimum prevalence of HAE in Italy in 2013 is 920:59,394,000 inhabitants, equivalent to 1:64,935. Compared to the general population, patients are less represented in the early and late decades of life: men start reducing after the 5(th) decade and women after the 6(th). Median age of patients is 45 (IQ 28-57), median age at diagnosis is 26 years (IQ 13-41). C1-INH-HAE type 1 are 87%, with median age at diagnosis of 25 (13-40); type 2 are 13% with median age at diagnosis of 31 (IQ 16-49). Functional C1INH is ≤50% in 99% of patients. Antigen C1INH is ≤50% in 99% of type 1. C4 is ≤50% in 96% of patients. The chance of having C1-INH-HAE with C4 plasma levels >50% is < 0.05. CONCLUSION: This nationwide survey of C1-INH-HAE provides for Italy a prevalence of 1:64,935. C1-INH-HAE patients listed in our database have a shorter life expectancy than the general population. An increased awareness of the disease is needed to reduce this discrepancy. Measurement of C4 antigen can exclude diagnosis of C1-INH-HAE with an accuracy > 95%. This parameter should be therefore considered for initial screening in differential diagnosis of angioedema.