The influence of exogenous methyl jasmonate on the germination and,content and composition of flavonoids in extracts from seedlings of yellow and narrow-leafed lupine

The aim of this study was to determine the influence of exogenous methyl jasmonate (MJ) on the content and composition of flavonoids (isoflavones) in extracts from hypocotyls (with cotyledons) and radicles of yellow lupine (Lupinus luteus L.) var. Polo and in extracts from radicles of narrow-leafed lupine (Lupinus angustifolius) var. Graf. Lupine seeds were harvested when fully ripe. Two months after harvest, the effect of various MJ concentrations (10⁻⁶ M to 10^-3M) on seed viability, seed vigor and the content and composition of flavonoids in extracts from seedlings that emerged from germinated lupine seeds (72 h, 20 °C) was determined. At high concentrations (10^-4 M to 10^-3 M), MJ suppressed the germination rate and germination capacity of seeds and decreased the growth rate of seedlings of the analyzed varieties of yellow and narrow-leafed lupines in the first 5 days of growth. In seedlings, MJ significantly increased the content of isoflavones (including daidzin, genistin, daidzein, and genistein) in 3-day-old hypocotyls (with cotyledons) and radicles of yellow lupine. This correlation was also observed in the hypocotyls (with cotyledons) and radicles of 3-day-old narrow-leafed lupine seedlings treated with MJ. Narrow-leafed lupine seeds were more sensitive to exogenous MJ then yellow lupine seeds during germination.     

Cross-reactivity between aeroallergens and food allergens

In patients with respiratory allergy, cross-reactivity between aeroallergens and foods may induce food allergy, symptoms ranging from oral allergy syndrome to severe anaphylaxis. Clinical entities due to IgE sensitization to cross-reactive aeroallergen and food allergen components are described for many sources of plant origin (pollen-food syndromes and associations, such as birch-apple, cypress-peach and celery-mugwort-spice syndromes, and mugwort-peach, mugwort-chamomile, mugwort-mustard, ragweed-melon-banana, goosefoot-melon associations), fungal origin (Alternaria-spinach syndrome), and invertebrate, mammalian or avian origin (mite-shrimp, cat-pork, and bird-egg syndromes). Clinical cases of allergic reactions to ingestion of food products containing pollen grains of specific plants, in patients with respiratory allergy to Asteraceae pollen, especially mugwort and ragweed, are also mentioned, for honey, royal jelly and bee polen dietary supplements, along with allergic reactions to foods contaminated with mites or fungi in patients with respiratory allergy to these aeroallergens. Medical history and diagnosis approach may be guided by the knowledge about the diverse cross-reacting allergens involved, and by the understanding of these clinical entities which may vary significantly or may be overlapping. The association between primary IgE sensitization with respiratory symptoms to inhaled allergens and food allergy due to cross-reactive allergen components is important to assess in allergy practice. The use of molecular-based diagnosis improves the understanding of clinically relevant IgE sensitization to cross-reactive allergen components from aeroallergen sources and foods.     

Antioxidant activity and phenolic content in three lupin species

Total phenolic compounds, phenolic acids and flavonoid contents and antioxidant activities were measured in extracts from seeds of Lupinus albus, Lupinus luteus and Lupinus angustifolius cultivars. The total phenolic compound contents varied from 491.51 to 731.14 mg/100 g d.m. for cvs. Butan (L. albus) and Parys (L. luteus), respectively. Protocatechuic acid was the most abundant in seeds of yellow lupin (up to 73.60 mg/kg d.m.), whereas p-hydroxybenzoic acid in narrow-leaf lupin (about 43 mg/kg d.m.). The HPLC (high performance liquid chromatography) analysis revealed two dominant flavonoid compounds, which were identified by HPLC/MSⁿ to be apigenin-6,8-di-C-β-glucopyranoside and apigenin 7-O-β-apiofuranosyl-6,8-di-C-β-glucopyranoside. The highest content of the apigenin glycosides was recorded in yellow lupin while the lowest in white lupin. A positive correlation between the content of the analyzed compounds and the antioxidant activity measured by 2,2′-diphenyl-1-picrylhydrazyl (DPPH) method was established, but no such relation was found using the radical-trapping antioxidant parameter (TRAP) method. Modification of the peroxyl radical-trapping potential of lupin extracts by formation of phenoxyl radicals is suggested.     

Isoflavones and antioxidant capacity of Peruvian and Brazilian lupin cultivars

Seed coats, cotyledons and hypocotyls from six Peruvian (Lupinus mutabilis Sweet) and two Brazilian (Lupinus albus and Lupinus angustifolius) lupin cultivars were assessed regarding their content of isoflavones and antioxidant capacity. Genistein and a genistein derivative were detected in seed coats and cotyledons from Peruvian cultivars. Total isoflavones ranged from 9.8 to 87, 16.1 to 30.8 and 1.3 to 6.1 mg/100 g of sample in fresh weight (expressed as genistein) in seed coat, cotyledon and hypocotyl fractions, respectively, from mutabilis species, whereas no isoflavones were detected in L. angustifolius and L. albus. A significant correlation (r = 0.99) was found between the total isoflavone levels and the antioxidant capacity measured by the 2,2-diphenyl-1-picrylhydrazyl radical-scavenging method in all fractions of Peruvian samples. No condensed tannins were detected in any of the lupin cultivars. The H-6 Andean cultivar is promising for its high isoflavone content and antioxidant capacity. Insights from this study indicate that lupin cultivars of the mutabilis species have similar isoflavone profiles and that isoflavones are more concentrated in the cotyledon seed fraction than in the seed coat or hypocotyl fractions.     

Exposure levels,determinants and IgE mediated sensitization to bovine allergens among Danish farmers and non-farmers

BackgroundBovine allergens can induce allergic airway diseases. High levels of allergens in dust from stables and homes of dairy farmers have been reported, but sparse knowledge about determinants for bovine allergen levels and associations between exposure level and sensitization is available.ObjectiveTo investigate levels and determinants of bovine allergen exposure among dairy, pig and mink farmers (bedroom and stable), and among former and never farmers (bedroom), and to assess the prevalence of bovine allergen sensitization in these groups.MethodsIn 2007–2008, 410 settled dust samples were collected in stables and in bedrooms using an electrostatic dust-fall collector over a 14 day period among 54 pig farmers, 27 dairy farmers, 3 mink farmers as well as 71 former and 48 never farmers in Denmark. For farmers sampling was carried out both during summer and winter. Bovine allergen levels (μg/m²) were measured using a sandwich ELISA. Determinants for bovine allergen exposure in stables and bedrooms were explored with mixed effect regression analyses. Skin prick test with bovine allergen was performed on 48 pig farmers, 20 dairy farmers, 54 former and 31 never farmers.ResultsBovine allergen levels varied by five orders of magnitude, as expected with substantially higher levels in stables than bedrooms, especially for dairy farmers. Bovine allergen levels in bedrooms were more than one order of magnitude higher for dairy farmers compared to pig farmers. Former and never farmers had low levels of bovine allergens in their bedroom. Bovine allergen levels during summer appeared to be somewhat higher than during winter.Increased bovine allergen levels in the bedroom were associated with being a farmer or living on a farm. Mechanical ventilation in the bedroom decreased bovine allergen level, significant for dairy farmers β = −1.4, p < 0.04. No other significant effects of either sampling or residence characteristics were seen. Allergen levels in dairy stables were associated to type of dairy stable, but not to other stable or sampling characteristics. Sensitization to bovine allergens was only found in one pig farmer.ConclusionThis study confirms high bovine allergen levels in dairy farms, but also suggests sensitization to bovine allergens among Danish farmers to be uncommon. Furthermore the importance of a carrier home effect on allergen load is emphasized. Whether the risk for bovine sensitization is related to the allergen level in the stable or the dwelling remains to be determined.     

Pollen-related food allergy: cloning and immunological analysis of isoforms and mutants of Mal d 1, the major apple allergen, and Bet v 1, the major birch pollen allergen

Summary Background: Mal d 1, the major apple allergen, cross-reacts with IgE specific for the major birch pollen allergen, Bet v 1, and is responsible for birch pollen related food allergy to apple. Isoforms of Bet v 1 showing minor sequence variations display different binding capacitiy for specific IgE antibodies from allergic patients. Moreover, strain-dependent variation of allergenicity has been reported for apples. Objective: To investigate the occurence of strain-dependent isoforms of Mal d 1 which may differ in their allergenic potential, to obtain data on structures essential for binding of Mal d 1 to the antibody, and to gain insights into the structures responsible for its IgE cross-reactivity to Bet v 1. Methods: The cDNA of Mal d 1 from various apple strains was amplified by a PCR strategy based on conserved regions of known Mal d 1-sequences, and sequenced. Two major isoforms of Mal d 1were expressed as recombinant proteins and purified, as were different variants of the major birch pollen allergen, Bet v 1. Together with already existing recombinant birch pollen and apple allergens, these were subjected to allergenicity testing by IgE-immunoblotting, enzyme allergo sorbent test and dose related mediator release. “Hot-spots” for IgE-reactivity were identified by site-directed mutagenesis. Results: Twelve Mal d 1-clones were sequenced from 7 apple varieties and compared to 3 known Mal d 1 sequences. The clones were clustered into two groups, each showing a high degree of sequence identity to one of the known sequences and specific differences to the third sequence. No strain-specific sequences were identified. In contrast, apple strains with reported differences in allergenicity showed different expression levels of the major allergen. Immunologic testing of recombinant allergens revealed high IgE binding capacity of 2 major isoforms, named GD26 and GS29, with a slightly higher IgE binding capacity of DG26. Moreover, the allergenicity was similar to another rMal d 1 reported in the literature, representing the isoform divergent from our clones. Mutational analysis of our Mal d 1 allergens identified serine in position 111 as essential for IgE binding. Allergenicity was almost depleted by changing this residue into a proline. Moreover, the corresponding serine residue, present in position 112 of Bet v 1, was in a similar manner crucial for the allergenicity of the birch pollen allergen. Conclusion: We conclude that divergent allergenicity of apple strains mainly depends on differnet expression levels of the major allergen. Introduction of a proline residue in position 111 of Mal d 1 and in position 112 of Bet v 1 led to a drastic reduction of allergenicity of both the pollen and the food allergen, obviously also removing the cross-reactive epitope. Mutants with reduced IgE-reactivity but maintained T-cell reactivity may represent new candidates for a safer specific immunotherapy with reduced side-effects. Received: 7 June 1999, Accepted: 30 July 1999     

Phenotypes and Endotypes of Peach Allergy: What Is New?

Peach allergy is emerging as a common type of fresh-fruit allergy in Europe, especially in the Mediterranean area. The clinical manifestations of peach allergy tend to have a peculiar geographical distribution and can range from mild oral symptoms to anaphylaxis, depending on the allergic sensitization profile. The peach allergen Pru p 7, also known as peamaclein, has recently been identified as a marker of peach allergy severity and as being responsible for peculiar clinical features in areas with high exposure to cypress pollen. This review addresses the latest findings on molecular allergens for the diagnosis of peach allergy, the clinical phenotypes and endotypes of peach allergy in adults and children, and management strategies, including immunotherapy, for peach allergy.     

Analysis of cross-reactivity between group 1 allergens from mites

Mite allergen exposure can lead to sensitization in genetically predisposed individuals, and the development of asthma in previously sensitized individuals. The major allergens of mites belong to Dermatophagoides spp. and Blomia tropicalis (Bt). Various allergens of Bt have been cloned and sequenced. Some of them show homology sequence with purified allergens from Dermatophagoides pteronissynus (Dp). Recently, the allergen group 1 from Bt, Blo t 1, was cloned and sequenced at our laboratory. Recombinant Blo t 1 showed 35 % of identity and 50% of similarity with group 1 allergens as Der p 1 (from Dp), Der f 1 (from D. farinae) and Eur m 1 (from Euroglyphus maynei) at amino acid level. This would suggest that cross-reactivity between allergens of different mite species could exist. Here, we analyzed the crossreactivity between group 1 allergens from mites using recombinant proteins and monoclonal antibodies against them. ELISA inhibition assay showed that crossreactivity between homologous allergens from Dermatophagoides spp. is high, but it is low to moderate between mites from different species. IgE-reactivity analysis using serum samples from allergic individuals revealed a strong reactivity of rBlo t 1 for serum samples from subjects with highly positive reaction to Bt extract in skin test, but lack of reactivity of this protein with serum samples from individuals with highly positive reaction to house dust mite extract in the skin test. These results suggest that it is important to include Bt allergens in routine skin test in order to improve the diagnostic accuracy and precision of allergies.     

Precision medicine allergy immunoassay methods for assessing immunoglobulin E sensitization to aeroallergen molecules

Molecular-based allergy diagnosis for the in vitro assessment of a patient immunoglobulin E (IgE) sensitization profile at the molecular level uses allergen molecules (also referred to as allergen components), which may be well-defined, highly purified, natural allergen components or recombinant allergens. Modern immunoassay methods used for the detection of specific IgE against aeroallergen components are either singleplex (such as the fluorescence enzyme immunoassay with capsulated cellulose polymer solid-phase coupled allergens, the enzyme-enhanced chemiluminescence immunoassay and the reversed enzyme allergosorbent test, with liquid-phase allergens), multiparameter (such as the line blot immunoassay for defined partial allergen diagnostics with allergen components coating membrane strips) or multiplex (such as the microarray-based immunoassay on immuno solid-phase allergen chip, and the two new multiplex nanotechnology-based immunoassays: the patient-friendly allergen nano-bead array, and the macroarray nanotechnology-based immunoassay used as a molecular allergy explorer). The precision medicine diagnostic work-up may be organized as an integrated “U-shape” approach, with a “top-down” approach (from symptoms to molecules) and a “bottom-up” approach (from molecules to clinical implications), as needed in selected patients. The comprehensive and accurate IgE sensitization molecular profiling, with identification of the relevant allergens, is indicated within the framework of a detailed patient’s clinical history to distinguish genuine IgE sensitization from sensitization due to cross-reactivity (especially in polysensitized patients), to assess unclear symptoms and unsatisfactory response to treatment, to reveal unexpected sensitizations, and to improve assessment of severity and risk aspects in some patients. Practical approaches, such as anamnesis molecular thinking, laboratory molecular thinking and postmolecular anamnesis, are sometimes applied. The component-resolved diagnosis of the specific IgE repertoire has a key impact on optimal decisions making for prophylactic and specific immunotherapeutic strategies tailored for the individual patient.     

A C-GL Ycosyl-Flavonol from The Seeds of Four Lupin Us Species

A search for flavonoid components in the seeds of four species of lupin, Lupinus albus, Lupinus angustifolius, Lupinus luteus and Lupinus mutabilis, revealed the presence in all of them of a single dominant compound, believed to be an apigenin di-C-glycoside. At levels varying from 0.16 mg (L. albus) to 0.37 mg (L. luteus) per 100 g of seed, this component seems unlikely to interfere significantly with protein utilisation or to confer anti-nutritional properties on lupinseed.     

Matrix effects of lupine (Lupinus luteus L.) and rapeseed (Brassica napus L.) products on in vitro non-haem iron availability from pork meat

Limited iron bioavailability is regarded as one of the most confounding factors responsible for low iron absorption and utilisation. In the gastrointestinal lumen of humans and monogastric animals, iron absorption is highly affected by dietary components that decrease or enhance iron availability. This study aims at investigating the matrix effects of lupine and rapeseed products on in vitro non-haem iron availability when included in meat-based diets. In vitro iron availability is measured as Fe(II) dialysability obtained by a method combining in vitro protein digestion and dialysis (IVPD dialysis). Aliquots were collected following digestion with pepsin or pepsin/pancreatin and investigated for their effects on Fe(II) dialysability. Thus, the IVPD imitates the conditions in the duodenum and the proximal jejunum. The method confirms that the major effects on in vitro non-haem iron availability are achieved during duodenal conditions. The results showed a significant enhancing effect of pepsin-digested pork meat on Fe(II) dialysability and a pronounced effect of the plant components on Fe(II) dialysability from meat proteins. Lupine enhances Fe(II) dialysability after pepsin/pancreatin digestion in contrast to rapeseed. Moreover, lupine may constitute a valuable vegetable food component in enhancing iron availability and solubility more distally in the intestine than observed for other enhancers of iron absorption.     

Effect of lactic acid fermentation of lupine wholemeal on acrylamide content and quality characteristics of wheat-lupine bread

Abstract

The effect of supplementing wheat flour at a level of 15% with lupine (Lupinus angustifolius L.) wholemeal fermented by different lactic acid bacteria on acrylamide content in bread crumb as well as on bread texture and sensory characteristics was analysed. The use of fermented lupine resulted in a lower specific volume and crumb porosity of bread on an average by 14.1% and 10.5%, respectively, while untreated lupine lowered the latter parameters at a higher level (30.8% and 20.7%, respectively). The addition of lupine resulted in a higher by 43.3% acrylamide content compared to wheat bread (19.4?µg/kg dry weight (d.w.)). Results showed that acrylamide was significantly reduced using proteolytic Lactobacillus sakei and Pediococcus pentosaceus 10 strains for lupine fermentation. Although the bread supplemented with lupine spontaneous sourdough had the lowest level of acrylamide (15.6?µg/kg?d.w.), it had the malodorous flavour and was unacceptable to the consumers. The lactofermentation could increase the potential use of lupine as a food ingredient while reducing acrylamide formation and enriching bread with high quality proteins.     

Homemade Food Allergen Extracts for Use in Skin Prick Tests in the Diagnosis of IgE-Mediated Food Allergy: A Good Alternative in the Absence of Commercially Available Extracts?

Introduction: The skin prick test (SPT) is the first step in the diagnosis of an immunoglobulin E (IgE)-mediated food allergy. The availability of commercial food allergen extracts is very limited, resulting in a need for alternative extraction methods of food allergens. The objective of this study was to compare the SPT results of homemade food allergen extracts with commercially available extracts. Methods: Adult patients with a suspected food allergy were included. Food allergen-specific symptoms were scored using a questionnaire. SPTs were performed with homemade and commercially available extracts (ALK-Abelló, Kopenhagen, Denmark) from almond, apple, hazelnut, peach, peanut, and walnut. Serum-specific IgE was measured with ISAC or ImmunoCAP™. Intra-class correlation coefficients (ICC) between the SPT results of both extract methods were calculated. The proportion of agreement with food allergen-specific symptoms was analyzed. Results: Fifty-four patients (mean age 36; range 19–69 years; female/male: 42/12) were included. The intra-class correlation coefficient (ICC) between the SPT results of both extract methods were strong for hazelnut 0.79 (n = 44) and walnut 0.78 (n = 31), moderate for apple 0.74 (n = 21) and peanut 0.66 (n = 28), and weak for almond 0.36 (n = 27) and peach 0.17 (n = 23). The proportion of agreement between SPT results and food allergen-specific symptoms was comparable for homemade and commercially available extracts, except for peach; 0.77 versus 0.36, respectively. Conclusion: In the diagnostic procedures to identify an IgE-mediated food allergy, homemade extracts from hazelnut and walnut appear to be a good alternative in the absence of commercially available food allergen extracts.     

House Dust Mite Exposure through Human Milk and Dust: What Matters for Child Allergy Risk?

Allergies are major noncommunicable diseases associated with significant morbidity, reduced quality of life, and high healthcare costs. Despite decades of research, it is still unknown if early-life exposure to indoor allergens plays a role in the development of IgE-mediated allergy and asthma. The objective of this study is to contribute to the identification of early-life risk factors for developing allergy. We addressed whether two different sources of house dust mite Der p 1 allergen exposure during early life, i.e., human milk and dust, have different relationships with IgE levels and asthma outcomes in children. We performed longitudinal analyses in 249 mother–child pairs using data from the PIAMA birth cohort. Asthma symptoms and serum total and specific IgE levels in children were available for the first 16 years of life. Der p 1 levels were measured in human milk and dust samples from infant mattresses. We observed that infant exposure to Der p 1 through human milk was associated with an increased risk of having high levels of serum IgE (top tertile > 150 kU/mL) in childhood as compared to infants exposed to human milk with undetectable Der p 1 [adjusted OR (95% CI) 1.83 (1.05–3.20) p = 0.0294]. The Der p 1 content in infant mattress dust was not associated with increased IgE levels in childhood. The risk of asthma and Der p 1 sensitization was neither associated with Der p 1 in human milk nor with Der p 1 in dust. In conclusion, high levels of IgE in childhood were associated with Der p 1 exposure through human milk but not exposure from mattress dust. This observation suggests that human milk is a source of Der p 1 exposure that is relevant to allergy development and fosters the need for research on the determinants of Der p 1 levels in human milk.     

Occupational asthma caused by samba (Triplochiton scleroxylon) wood dust in a professional maker of wooden models of airplanes: A case study

Objectives

Wood dust is a known occupational allergen that may induce, in exposed workers, respiratory diseases including asthma and allergic rhinitis. Samba (obeche, Triplochiton scleroxylon) is a tropical tree, which grows in West Africa, therefore, Polish workers are rarely exposed to it. This paper describes a case of occupational asthma caused by samba wood dust.

Material and Methods

The patient with suspicion of occupational asthma due to wood dust was examined at the Department of Occupational Diseases and Clinical Toxicology in the Nofer Institute of Occupational Medicine. Clinical evaluation included: analysis of occupational history, skin prick tests (SPT) to common and occupational allergens, determination of serum specific IgE to occupational allergens, serial spirometry measurements, metacholine challenge test and specific inhalation challenge test with samba dust

Results

SPT and specific serum IgE assessment revealed sensitization to common and occupational allergens including samba. Spirometry measurements showed mild obstruction. Metacholine challenge test revealed a high level of bronchial hyperactivity. Specific inhalation challenge test was positive and cellular changes in nasal lavage and induced sputum confirmed allergic reaction to samba.

Conclusions

IgE mediated allergy to samba wood dust was confirmed. This case report presents the first documented occupational asthma and rhinitis due to samba wood dust in wooden airplanes model maker in Poland.     

血清过敏原特异性IgE检测中存在问题及对策

目的了解儿童总IgE和过敏原特异性IgE的分布情况及变化规律,为儿童过敏性疾病防治提供依据。方法对2017年8月—2018年2月在湖州市妇幼保健院就诊的338名儿童进行总IgE、过敏原特异性IgE检测,采用胶体金法检测总IgE抗体,用免疫印迹法检测过敏原特异性IgE抗体。结果在检测的338名儿童中,总IgE阳性率为56.51%(191/338),过敏原特异性IgE抗体阳性儿童占36.69%(124/338), 其中61.29%为单一物质过敏,38.71%为2种或以上物质过敏;不同性别之间总IgE、过敏原特异性IgE差异均无统计学意义(P＞0.05)。吸入性过敏原特异性IgE阳性率为18.64%(63/338),以户尘螨为主;食物性过敏原特异性IgE阳性率为40.24%(136/338),以鸡蛋白和牛奶为主。随着年龄增长总IgE、吸入性过敏原逐渐增高,而食物性过敏原逐步减少,差异均有统计学意义(P＜0.05)。结论户尘螨、鸡蛋白和牛奶是婴幼儿最主要的过敏原,早期预防的重点应放在食物性过敏原,而随着年龄增长需警惕吸入性过敏原引起的超敏反应。血清总IgE和过敏原特异性IgE的检测有利于了解过敏状态,能更好地为儿童过敏性疾病的预防、诊断和治疗提供帮助。     

Seafood Allergy,Toxicity, and Intolerance: A Review

Seafood allergies have been increasing their presence in the last 2 decades. Allergic reactions to seafood can range from mild urticarial and oral allergy syndrome to life-threatening anaphylactic reactions. Ingestion of seafood infested with Anisakis larvae can cause a disease known as anisakiasis with symptoms similar to true seafood allergy. Furthermore, some adverse reactions to seafood including histamine fish poisoning (HFP), and intolerance to histamine can trigger clinical symptoms, which, although nonallergic in origin, are similar to true immunoglobulin E (IgE)-mediated allergic reactions. Because seafood allergy usually remains a lifelong food allergy, this review focuses on the current knowledge on fish and shellfish allergens and emphasizes the importance of differentiating seafood allergy from other allergy-like reactions (anisakiasis, HFP, and intolerance to histamine).

Key teaching points:

? Fish and shellfish are potent allergens that can provoke serious IgE antibody-mediated adverse reactions in sensitive individuals.

? Sensitization to seafood allergens can be achieved by ingestion, inhalation, or skin contact.

? Shellfish major allergen, tropomyosin, shares significant homology to arthropods (dust mites and cockroaches).

? Accidental exposures to seafood products cross-contaminated with fish or shellfish allergens (hidden allergens) during processing may present a health risk for sensitive individuals.

? Allergens of fish parasite A. simplex present common hidden allergens in seafood, particularly in raw and undercooked home-made fish dishes.

? Symptoms caused by HFP, histamine intolerance, and anisakiasis are similar to true seafood allergy.     

Spreading of occupational allergens: laboratory animal allergens on hair-covering caps and in mattress dust of laboratory animal workers

Background

Family members of laboratory animal workers are at risk of developing allergy to laboratory animals. Little is known about the spreading of laboratory animal allergens outside the animal facilities.

Objective

To assess the presence of laboratory animal allergens in dust collected from mattresses of laboratory animal workers and unexposed controls.

Methods

Mouse and rat urinary proteins were measured in samples of mattress dust collected by laboratory animal workers and unexposed controls. In addition, rat and mouse allergens were determined in extracts of hair‐covering caps, used during laboratory animal work, to estimate spreading of allergen through dust captured on hair. Allergen concentrations on hair caps were compared with exposure measured by personal airborne dust sampling.

Results

Levels of rat urinary allergens (RUA) and mouse urinary allergens (MUA) and mouse urinary protein (MUP) 8, a specific pheromone‐binding mouse allergen, were significantly higher in mattress samples of laboratory animal workers than in those of controls. Hair‐covering caps used in animal facilities harboured large amounts of RUA and MUA, which correlated significantly with exposure measured by the personal sampling technique in the animal facility.

Conclusions

Occupational laboratory animal allergens are detectable in mattress dust of laboratory animal workers. Transfer of allergens via uncovered hair of animal workers is likely contributing to this phenomenon. This study stresses the importance of using hair caps to prevent spreading of occupational allergens.Occupational allergy against laboratory animals is a common problem among laboratory animal workers. The prevalence of laboratory animal allergy is reported to be 10–25%.¹ Allergens of laboratory animals are potent sensitisers and small amounts can elicit symptoms in sensitised individuals. Moreover, there are also indications that reduction of exposure may lead to a decreased incidence of laboratory animal allergy.^2,3,4 Methods for controlling exposure to laboratory animal allergens include the choice of bedding materials and adjustment of cage‐changing processes, and the use of personal protective equipment.⁵ Despite the fact that the risk of developing laboratory animal allergy is high and personal protective equipment is widely available, respiratory protection is not routinely used. Laboratory coats and protective gloves are widely used, but the use of hair‐covering caps and facemasks is mostly restricted to already sensitised individuals to prevent symptoms.Although direct contact with animals probably accounts for most of the airway exposure, a possibly underestimated route of exposure may be subsequent exposure to allergens transferred from the animal facility through hair, clothing and documents.⁵ It was shown for cat allergen that transfer can lead to exposure of individuals without direct contact with animals.^6,7 Moreover, children of laboratory animal workers were shown to have an increased risk of developing laboratory animal allergy,⁸ suggesting that subsequent exposure also influences allergen loads in houses of laboratory animal workers and may sensitise family members.It has been suggested that allergens captured in human hair can play an important role in exposure to laboratory animal allergens outside the animal facility. So far, evidence supporting the relevance of this route of exposure is scarce, but animal workers are generally advised to wash their hair after work to prevent contamination of the home environment with occupational aeroallergens.⁵ The use of hair‐covering caps is another method to prevent allergen transfer through human hair. Despite this advice, regular use of hair caps or washing hair after finishing work was a standard procedure in <20% of the laboratory animal facilities we studied in The Netherlands. By contrast, special clothing was used in all facilities.We measured the levels of laboratory animal allergens in the mattress dust of laboratory animal workers and compared it with allergen concentrations in mattresses of controls who are not occupationally exposed. The allergen load on hair‐covering caps used by laboratory animal workers was measured to assess whether carry‐over through the hair of workers may be a relevant route of allergen transfer. In addition, the allergen load on hair‐covering caps was compared with the level of airborne exposure as determined by the personal airborne‐dust sampling technique.