R-mandelonitrile-lyase, homolog to Pru d 10, is a major peach allergen in peach allergic Spanish population.

BACKGROUND AND OBJECTIVE: Peach allergy is a prevalent cause of food allergy. Despite the repertoire of allergens available for molecular diagnosis, there are still patients with undetectable IgE levels to peach allergens but presenting symptoms after its ingestion. The objective of this study was to investigate the allergenic profile in a patient population with symptoms produced by peach. METHODS: An exploratory retrospective study was performed with patients presenting symptoms after the ingestion of peach. Forty-two patients were included in the study. The allergenic profile of individual patients was investigated by immunoblot. A serum pool was prepared with the sera that recognized a 70 kDa band. This pool was used to detect this protein in peach peel and pulp and to identify the 70 kDa protein in 2D immunoblot. Spots recognized in the 2D immunoblot were sequenced by LC-MS/MS. Inhibition studies were performed between peach peel and almond. RESULTS: Twenty-two patients (52.4%) recognized the 70 kDa protein in immunoblot. This protein was recognized in peel and pulp. Two different spots were observed in 2D-PAGE, both were identified as (R)-mandelonitrile lyases (RML) with high amino acid similarity with Pru du 10. Peach RML were partially inhibited with an almond extract. No association was found between any reported symptom and sensitization to RML. RML-sensitized patients were older and reported pollen associated respiratory symptoms more frequently than negative patients. CONCLUSION: A new peach allergen, a RML, homologous of Pru du 10, recognized by 52% of the population has been identified.

Differences in molecular sensitization profiles between a Spanish and Latin American mite allergic patients.

BACKGROUND AND OBJECTIVE: To analyze the sensitization pattern to Dermatophagoides pteronyssinus and to associate the diagnostic findings and clinical severity in 218 allergic patients from two different continents. METHODS: Mite allergic patients were recruited by the Allergology departments from Latin America (n=88: Colombia, Costa Rica and Guatemala) and Spain (N=130). All patients had allergic rhinitis with or without asthma and positive skin prick test results to D. pteronyssinus. Specific IgE levels to D. pteronyssinus, D. farinae, Der p 1, Der p 2, and Der p 23 were quantified by ImmunoCAP system (ThermoFisher Scientific). Allergenic profile was also determined by western blot. Comparative Statistical analysis was performed by GraphPad software. RESULTS: Patients recognized most frequently Der p 2 (79%) followed by Der p 1 (73%), and Der p 23 (69%) allergens. The percentage of asthmatic patients increases with the number of sensitizations however none statistically significant differences were found. Interestingly, asthmatic patients presented the highest median levels of total IgE and specific IgE levels of D. pteronyssinus and molecular allergens, mainly Der p 2. Analysing the two different populations, Spanish patients were predominantly sensitized to Der p 2 (88.46%) and Der p 1 (83.84%), whereas Latin American population were more sensitized to Der p 23. CONCLUSION: Our data support the relevance of Der p 2 in mite allergy as the major allergen, with the high number of patients sensitized to it and its importance in the development of asthma. Sensitization to Der p 23 was more important in Latin America.

Sensitization to Vitis vinifera Pollen in a Wine Production Area: Identification of the Allergens Involved.

BACKGROUND: Vine cultivation is widely distributed in La Rioja, Spain (37% of all crops) and is associated with exposure of the general population to vine pollen. The aims of this study were to investigate the prevalence of sensitization to Vitis vinifera pollen in persons with respiratory allergy in the general population and to identify the allergens involved. MATERIALS AND METHODS: The study population comprised patients who came to the hospital between September 2019 and January 2020 with suspected respiratory allergy. All patients underwent skin prick testing with a panel of standardized aeroallergens, profilin, lipid transfer protein (LTP), and V vinifera pollen extract and prick-prick testing with fresh grapes. The in vitro study included specific IgE by ImmunoCap and ELISA, allergenic profile by immunoblot with individual sera from patients positive to V vinifera pollen extract, and 2D immunoblot with a pool of sera. The spots recognized by IgE were identified using mass spectrometry. RESULTS: A total of 151 patients were included. Of these, 124 were positive to some of the allergens tested. Thirty-four (27.4%) were positive to vine pollen in the skin prick tests. The serology study revealed positive results in 20 patients. Five vine pollen allergens were identified, and profilin was the most prevalent (30%). The other 4 allergens could be considered specific to this pollen. CONCLUSIONS: Sensitization to vine pollen was frequent in the general population in a vine growing area. The clinical relevance of this finding is unknown owing to sensitization to other pollens in the vine pollen-positive patients. Five new vine pollen allergens were identified.

Molecular Diagnosis in House Dust Mite-Allergic Patients Suggests That Der p 23 Is Clinically Relevant in Asthmatic Children.

BACKGROUND: Patterns of sensitization to house dust mites depend on geographic area and are important in clinical practice. However, the role of molecular diagnosis is not currently defined. We sought to characterize a pediatric population by focusing on sensitization to different mite species and major mite components in order to assess the clinical relevance of sensitization to allergenic components in our practice. METHODS: Consecutive children with respiratory allergy sensitized to house dust mites (determined by skin prick test [SPT]) were recruited. We determined specific IgE to nDer p 1, rDer p 2, and rDer p 23 using ImmunoCAP and sIgE using ImmunoCAP-ISAC microarray. Patients were followed up for 3 years. RESULTS: A total of 276 children were recruited. The frequency of sensitization was 86.6% for nDer p 1, 79.3% for rDer p 2, and 75.8% for rDer p 23. Lepidoglyphus species was the most common storage mite detected by SPT. Twenty-six patients (9.4%) were not sensitized to Der p 1 or Der p 2. It is noteworthy that IgE binding to Der p 23 was positive in 14 (53.8%). Asthmatic patients, especially those with a persistent moderate-severe phenotype, more frequently recognized the 3 major allergens. CONCLUSIONS: Most patients with mite allergy were sensitized to the major allergens Der p 1, Der p 2, and Der p 23. Of the allergens evaluated, 5% were sensitized to Der p 23 but not to Der p 1 or Der p 2. Sensitization to Der p 23 should be considered in the diagnosis and treatment of mite allergy, especially in patients with moderate-severe asthma, because it may worsen the clinical phenotype.

Standardization of allergen products: 3. Validation of candidate European Pharmacopoeia standard methods for quantification of major birch allergen Bet v 1.

BACKGROUND: The BSP090 project aims at establishing European Pharmacopoeia Reference Substances in combination with the corresponding ELISA methods for the quantification of major allergens in allergen products. Two sandwich ELISAs proved suitable for quantification of Bet v 1, the major birch pollen allergen, in preceding phases of BSP090. METHODS: Two Bet v 1-specific ELISA systems were compared with respect to accuracy and precision in a ring trial including 13 laboratories. Model samples containing recombinant rBet v 1.0101 as well as native birch pollen extracts were measured independently at least three times in each facility. The assessment was completed with a comparative quantification of Bet v 1 in 30 marketed birch allergen products in one laboratory, simulating the future use as reference method. RESULTS: In the collaborative study, both candidate ELISAs confirmed their suitability to quantify recombinant and native Bet v 1. ELISA-A showed higher precision and lower interlaboratory variability, yet ELISA-B exhibited slightly higher accuracy. Subsequent parallel measurement of Bet v 1 in a panel of 'real-life' birch allergen products indicated better repeatability of ELISA-B. Both systems detected substantial differences in Bet v 1 content between allergen products, but the effect was more pronounced using ELISA-B due to persistently higher values compared to ELISA-A. CONCLUSIONS: In the collaborative study, no deciding differences were observed between the two candidate ELISAs. Further comparison under conditions simulating the intended use combined with the criterion of long-term availability enabled the selection of one Bet v 1-specific ELISA for proposal as European Pharmacopoeia standard method.

Relevance of Allergenic Sensitization to Cynodon dactylon and Phragmites communis: Cross-reactivity With Pooideae Grasses.

BACKGROUND AND OBJECTIVES: The homologous group of sweet grasses belongs to the Pooideae subfamily, but grass pollen species from other subfamilies can also cause allergy, such as Cynodon dactylon (Chloridoideae) and Phragmites communis (Arundinoideae). C dactylon and P communis have not been included in the sweet grasses homologous group because of their low cross-reactivity with other grasses. The aims of this study were to investigate the profile of sensitization to C dactylon and P communis in patients sensitized to grasses and to analyze cross-reactivity between these 2 species and temperate grasses. METHODS: Patients were skin prick tested with a grass mixture (GM). Specific IgE to GM, C dactylon, P communis, Cyn d 1, and Phl p 1 was measured by ImmunoCAP. A pool of sera was used for the immunoblot assays. Cross-reactivity was studied by ELISA and immunoblot inhibition. RESULTS: Thirty patients had sIgE to GM. Twenty-four (80%) had positive results for C dactylon, 27 (90%) for P communis, 22 (73.3%) for nCyn d 1, and 92.9% for rPhl p 1. Bands were detected in the 3 extracts by immunoblot. Inhibition of GM was not observed with C dactylon or P communis by immunoblot or ELISA inhibition. When C dactylon or P communis were used in the solid phase, GM produced almost complete inhibition. CONCLUSIONS: Eighty percent of patients sensitized to grasses were also sensitized to C dactylon and 90% were sensitized to P communis. Sensitization to these species seems to be induced by allergens different to those in sweet grasses.

Tomato nsLTP as an "In Vivo" Diagnostic Tool: Sensitization in a Mediterranean Population.

BACKGROUND: Tomato allergies have been extensively studied but component-resolved in vivo diagnosis with purified allergens has yet to be performed. OBJECTIVES: To evaluate the prevalence of sensitization to Sola l 3 in a Mediterranean population, and to compare the resulting sensitization profile with that of individuals sensitized to tomato, peach, and/or purified lipid transfer protein (LTP). METHODS: Sola l 3 was purified, characterized, and used to prepare skin prick tests (SPTs). Two groups of patients were selected. Group 1 consisted of patients with at least 1 positive SPT to tomato, peach, or LTP mixture (marker extracts) who were subsequently tested with Sola l 3 (n = 280). Group 2 (prevalence study) consisted of patients who underwent simultaneous SPT with the 3 marker extracts and Sola l 3 (n = 658). Patients from either group who were positive to any of the 4 extracts were studied in detail (study group, n = 1 23). ELISA and immunoblot assays were performed in individuals with a positive SPT to Sola l 3 to detect the presence of specific IgE antibodies to this allergen. RESULTS: Prevalence of sensitization to Sola l 3 was 3.2% overall and 54.7% in tomato-positive patients. Most tomato-sensitized patients were asymptomatic. Symptoms were more common in Sola l 3-positive individuals. Sensitization to peach and the LTP mixture did not discriminate between Sola l 3-positive and Sola l 3-negative patients. CONCLUSIONS: This study confirms that LTP, not only from peach but also from other fruit and vegetables, including tomato, is an important allergen in the Mediterranean area. Sensitization to Sola l 3 is associated with more symptoms in tomato-sensitized patients.

Allergological characterisation of the storage mite Acarus gracilis (Acari: Acaridae).

BACKGROUND: Storage mites of the genus Acarus can be responsible for allergic sensitisation in domestic environments. Acarus gracilis is a frequent species in some geographical regions of the Iberian Peninsula. Since the allergenicity of this mite has not been described before, the objectives of this study were to characterise it immunologically, and to compare it with the closely related and more extensively studied species Acarus siro. METHODS: Extracts from A. gracilis and A. siro cultures were characterised by Lowry, 1D and 2D-SDS and IEF. Zymogram, and determination of different enzymatic activities were performed. Skin prick solution of A. gracilis was tested in consecutive patients attending the Hospital of Mérida (Extremadura, Spain). Serum samples from eight individuals with positive skin prick test were collected. IgE determination, immunoblot and immunoblot-inhibition studies were performed. RESULTS: Extracts of both species showed a very similar protein and allergenic profile. Allergens at 14 and 17 kDa were clearly recognised in both extracts by serum samples. Immunoblot-inhibition studies demonstrated that both extracts were totally inhibited by the opposite one. Enzymatic activity was similar in both cases with the most important differences being in kallikrein, serine protease and collagenase activities. CONCLUSION: The storage mite A. gracilis has a similar protein and allergen profile to A. siro and can induce allergic sensitisation. Due to the higher prevalence of this species respect to A. siro in some regions, more studies are needed to determine the clinical significance of sensitisation to this storage mite species.

Allergy to goat and sheep cheese with tolerance to cow's milk and its derivatives.

OBJECTIVE: We present two adult and three paediatric patients who had allergic reactions after cheese ingestion and subsequently tolerated cow's milk derivatives. The objective of this study was to determine possible cross-reactivity between different types of cheese. METHODS: Skin tests were performed to cow's milk fractions, and prick-prick tests for goat, sheep and cow cheese. Specific IgE to the fractions of cow's milk and cow, sheep and goat cheese was analysed. The protein profile of cow, sheep and goat cheese extracts was determined by SDS-PAGE and the allergenic profile by immunoblot. Cross-reactivity was investigated by immunoblot inhibition. RESULTS: Skin tests were positive for casein in the patients. The prick-prick tests were positive for the three cheeses in patients 1 and 4, for goat and sheep cheese in patients 2 and 3, and for sheep cheese in patient 5. The specific IgE test was positive in patients 1, 3 and 4 for goat and sheep cheese, and negative in patients 2 and 5. Serum 3 and 4 clearly recognised goat and sheep cheese extracts. Goat casein was almost completely inhibited with sheep casein and partially inhibited with goat and sheep serum proteins, while there was no inhibition with cow cheese. Sheep casein was totally inhibited with sheep serum proteins. Sheep casein was inhibited with goat and cow caseins, suggesting cross-reactivity among the three types of cheese. CONCLUSIONS: We showed sensitisation to goat and sheep cheese in two patients, and only to sheep cheese in another two of the studied patients.

Profilin sensitisation in a Mediterranean population.

BACKGROUND: Sensitisation to pan-allergens has become an interesting tool for the study of the allergenic profile of different populations. Profilins are one of the most common pan-allergens to be studied because they are responsible for a large number of sensitisations and are clearly related to cross-reactivity and co-sensitisation. OBJECTIVES: The objective of this study was to investigate the profile of sensitisation to profilins and to correlate it with sensitisation to foods and pollens. METHODS: Six hundred and fifty-four consecutive patients were skin-prick tested with a battery of common allergens including pollens, epithelia, mites and moulds and profilin and divided into three groups depending on their sensitisation profile (non-atopic, atopic with pollinosis and atopic without pollinosis). Patients with symptoms were challenged and diagnosed with the offending food extracts. Profilin sensitisation was identified and analysed in detail. RESULTS: According to the classification of the population, the prevalence of profilin sensitisation was estimated at 2.9% in patients suffering respiratory allergy, 4.2% in atopic patients, and 5.9% in pollen-sensitised individuals. Positive association was observed between pollen (except Cupressus and olive) and profilin but not with moulds, mites or epithelia. With respect to foods, positive association was only observed between profilin and melon sensitisation. Lastly, in terms of symptoms, positive association was only observed between profilin sensitisation and OAS. CONCLUSION: Profilin sensitisation seems to be a marker of pollen-related poly-sensitisation in our area. Pan-allergen diagnosis seems to be an essential tool for developing and improving selection of the correct treatment for allergic patients.

Occupational allergy to aquarium fish food: red midge larva, freshwater shrimp, and earthworm. A clinical and immunological study.

BACKGROUND: Chironomids seem to be the main cause of occupational allergy to aquarium fish food. OBJECTIVE: The aim of this study was to investigate the pattern of occupational sensitization to 3 different arthropod species used as components of aquarium fish food. METHODS: The study sample comprised 8 workers from a fish food packing department. The control group comprised 40 atopic patients (20 of whom were allergic to mites). We performed prick tests with extracts of red midge larva (Chironomus thummi), freshwater shrimp (Gammarus species), earthworm (Tubifex species), and other arthropod species and a battery of common inhalant allergens. We measured peak expiratory flow rate (PEFR) and specific immunoglobulin (Ig) E and performed a methacholine challenge test, nasal challenge test, and immunoblotting. Cross-reactivity analyses were completed using immunoblotting and CAP inhibition. RESULTS: Prick test results were positive to red midge larvae in 7 patients (87.5%), Gammarus in 5 (62.5%), Tubifex in 3 (37.5%), and mites in 6 (75%). In the mite-allergic controls, 30% had positive prick test results to red midge larvae. PEFR decreased > or = 20% during the packing process in all patients, and in 1 patient it indicated a dual asthmatic response. Methacholine challenge test results were positive in all participants. Nasal challenge tests were performed in 4 patients, and the results were positive. Specific IgE to red midge larvae was detected in 62.5%, Gammarus in 50%, and Tubifex in 16%. Bands of approximately 14-15 kDa and 31 kDa were observed in Gammarus and red midge larvae extracts. Cross-reactivity assays demonstrated that Gammarus totally inhibited red midge larvae, while Tubifex did so partially. Dermatophagoides pteronyssinus showed very low inhibitory capacity. CONCLUSIONS: Aquarium fish food arthropods are potent allergens with an elevated prevalence of sensitization and variable degree of crossreactivity. This is the first report of occupational allergy to Tubifex. More data are necessary to identify and characterize the responsible allergens.

Knee cartilage defects in a sample of older adults: natural history, clinical significance and factors influencing change over 2.9 years.

OBJECTIVE: To describe the natural history of knee cartilage defects, and their relationship to cartilage volume loss and risk of knee replacement in a longitudinal study of older adults. DESIGN: 395 randomly selected older adults (mean age 62.7 years) had magnetic resonance imaging of their right knee at baseline and approximately 2.9 years later to determine cartilage defect grade (0-4), cartilage volume, medial and lateral tibial bone size, and presence of bone marrow lesions (BMLs). Height, weight, body mass index (BMI) and radiographic osteoarthritis were measured by standard protocols. RESULTS: At baseline higher grade cartilage defects (grade ≥2) were significantly associated with age, BMI, lateral tibial bone size, BMLs, and radiographic osteoarthritis. Over 2.9 years, the average defect score increased statistically significantly in all compartments; however, the majority of defects remained stable and regression of defects was rare. Baseline factors associated with increase in defect score over 2.9 years were radiographic osteoarthritis, tibial bone size, BMI and being female. In multivariate analysis, baseline cartilage defect grade predicted cartilage volume loss at the medial tibia, lateral tibia and patella over 2.9 years (ß = -1.78% to -1.27% per annum per 1 grade increase, P < 0.05 for all comparisons), and risk of knee replacement over 5 years (odds ratio (OR) = 1.73 per 1 grade increase, P = 0.001). CONCLUSION: Knee cartilage defects in older adults are common but less likely to regress than in younger life. They independently predict cartilage volume loss and risk of knee replacement, suggesting they are potential targets for intervention.

Immunogenicity of Phleum pratense depigmented allergoid vaccines: experimental study in rabbits.

BACKGROUND: Immunogenicity studies are based on accurate preclinical and clinical assessment of pharmaceutical products. The immunogenicity of modified allergen vaccines has not been fully elucidated, and the mechanisms involved are not well understood. Animal and human models have recently shown that depigmented allergoids induce specific immunoglobulin (Ig) G against individual allergens, thus supporting the clinical efficacy of these vaccines. OBJECTIVE: The aim of this study was to investigate the production of specific IgG against individual antigens and their isoforms in rabbits injected with depigmented allergoid extracts of Phleum pratense pollen. METHODS: Two New Zealand rabbits were immunized with depigmented-polymerized extracts adsorbed onto aluminum hydroxide (Depigoid) of P pratense. Rabbits were injected 3 times (35 microg Phl p 5). Specific IgG titers against native, depigmented, and depigmented-polymerized extracts and individual allergens (rPhl p 1 and rPhl p 5a) were analyzed by direct enzyme-linked immunosorbent assay. The capacity of these synthesized antibodies to recognize individual native and depigmented allergens and different isoforms was evaluated by immunoblot and 2-D analysis. RESULTS: All rabbits produced high titers of specific IgG against the 3 extracts. Rabbits injected with depigmented allergoids produced similar specific antibody titers against native, depigmented, and depigmented-polymerized extracts. Serum samples recognized individual allergens and their isoforms in the nonmodified extracts. CONCLUSION: Vaccines containing depigmented allergoid extracts of P pratense induce immunogenicity in vivo. The antibodies produced after injection of these extracts clearly recognized allergens and different isoforms in their native configuration.

Goji berries (Lycium barbarum): risk of allergic reactions in individuals with food allergy.

BACKGROUND: New foods are frequently introduced in Western diets for their healthy properties; however, they may produce adverse effects. OBJECTIVE: After attending a patient who experienced an allergic reaction to Goji berries, we evaluated the allergenic potential of this food in plant food-allergic individuals, a group that is considered to be at high risk of experiencing a reaction. METHODS: We recruited 30 additional plant food-allergic individuals in Spain during 3 months in 2010. Four patients reported symptoms on intake, 6 tolerated the berries, and 20 had never tried Goji berries. Patients underwent skin prick tests with Goji berries, as well as with peach peel and plant food panallergens as markers of cross-reactivity between unrelated foods. We carried out in vitro tests in symptomatic patients. RESULTS: Skin tests to Goji berries were positive in 24 patients (77%): 5 symptomatic patients and 19 asymptomatic patients. Positivity to Goji berries was associated with positivity to peach peel and to the panallergen nonspecific lipid transfer protein (LTP). Nearly half of the patients reported symptoms (45%), but 89% of the skin test-positive patients had never eaten Goji berries. We detected specific immunoglobulin E to Goji berries in all cases, and several individuals recognized 2 protein bands in the immunoblot. Addition of LTP to sera mostly inhibited immunoglobulin E binding to an LTP-like band, suggesting a role for this panallergen in sensitization to Goji berries. CONCLUSIONS: Our results demonstrate the allergenic potential of Goji berries in high-risk individuals, which is probably due to cross-reactivity with LTP from other foods. The risks of Goji berries should be taken into consideration in individuals with food allergy, especially those who are allergic to LTP.