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Genetics of equine insect bite hypersensitivity and genetic diversity in horses
Shrestha, Merina - \ 2017
Wageningen University. Promotor(en): Henk Bovenhuis; D.J. de Koning, co-promotor(en): Bart Ducro; A.M. Johansson. - Wageningen : Wageningen University - ISBN 9789463430166
paarden - equus - insectenbeten - overgevoeligheid - diergenetica - genetische diversiteit - genetische variatie - allergische reacties - horses - insect bites - hypersensitivity - animal genetics - genetic diversity - genetic variation - allergic reactions
Genetic variation contributing to the phenotypic variation was utilized in this thesis to understand the genetic background of a complex trait IBH, and to understand genetic diversity and relationships between various horse populations.
IBH is the most common skin allergic disorder in horses, caused by bites of midges, predominantly Culicoides species. It affects various horse breeds worldwide. With no effective treatment, IBH degrades horse health and causes economic loss. In this thesis, we used genome-wide SNPs to identify regions contributing to genetic variance of IBH susceptibility. We also investigated influence of increased number of horses and dense SNPs on identification of genomic regions associated to IBH susceptibility. Multiple genomic regions with small effects were observed in Studies I-III. Interesting genomic regions in the Icelandic horse population across the studies I and II, was observed on chromosomes 1, 7, 10, 15 and 17. The percentage of the genetic variance explained by top ten windows increased from 3.07% (Study I) to 6.56% (Study II). Novel genomic regions were identified when number of Icelandic horses was increased in Study II. Using dense SNPs on the Exmoor pony population we identified novel genomic regions, on chr 8, associated to IBH susceptibility, though with borderline significance.
In Study IV, pre-conceived understanding about evolutionary history of horse populations matched obtained results from investigation of genetic relationships within Dutch warmblood populations (pairwise mean FST ≤ 0.070), and within pony-like populations (pairwise mean FST ≤ 0.078). Horse populations with similar genetic background might share similar genetic components for IBH susceptibility. The Friesian horse population had lowest diversity (mean inbreeding coefficients: fi: 30.4%, fiROH= 22.2%) in Study IV and was genetically distinct (FST ranged from 0.13 to 0.17). This might be a result of a history of several population bottlenecks and selection on a closed breeding scheme. Low diversity in immunity related genes, observed in the Friesian horse population, might have led to increased prevalence of IBH. Similarly, low susceptibility of IBH in a warmblood population, KWPN sport horse population might be due to high genetic diversity ( =-6.9%). High genetic diversity in KWPN sport horse population might be a result of an open breeding scheme and interbreeding with other warmblood populations.
Culicoides obsoletus allergens for diagnosis of insect bite hypersensitivity in horses
Meide, N.M.A. van der - \ 2013
Wageningen University. Promotor(en): Huub Savelkoul, co-promotor(en): Edwin Tijhaar. - S.l. : s.n. - ISBN 9789461736697 - 228
paarden - equus - culicoides obsoletus - insectenbeten - allergenen - overgevoeligheid - allergieën - cytokinen - diagnose - elisa - vectoren, ziekten - immunologie - horses - insect bites - allergens - hypersensitivity - allergies - cytokines - diagnosis - disease vectors - immunology
AInsect Bite Hypersensitivity (IBH) is the most common skin allergy in horses and involves a Type I (IgE mediated) hypersensitivity reaction against bites of insects, mainly of the Culicoides species. Welfare of affected horses is seriously reduced and no fully curative treatment is yet available. Furthermore, current diagnostic tests are unreliable because of their low sensitivity and specificity. Aim of our research was to increase the understanding of immunological aspects of IBH, with special attention to improving diagnosis by the characterization and production of recombinant allergens.
Whole body extracts (WBE) of three Culicoides species: C. obsoletus C. nubeculosus and C. sonorensis were evaluated for their applicability for diagnosis of IBH in horses in The Netherlands. They were tested for IgE binding by ELISA and Western blotting and for their capacity to degranulate basophils in a histamine release test. For all tests, best results were obtained with C. obsoletus. The ELISA was further evaluated using C. obsoletus extract on approximately 200 IBH affected and healthy horses, which demonstrated high test sensitivity and specificity. C. obsoletus-specific IgE serum levels were found to be the same in the IBH season and off season, suggesting that the test can be used to diagnose horses in winter when clincial symptoms are absent.
Since C. obsoletus was found to be the most important species for diagnosis of IBH in The Netherlands, mRNA of this Culicoides species was sequenced and assembled to create a transcriptome. Using the sequences from in literature described allergens from C. nubeculosus and C. sonorensis, similarity searches were performed on this transcriptome,. This resulted in the identification of seven allergens from C. obsoletus. These allergens were cloned and expressed as recombinant proteins in E. coli and named Cul o 1 – Cul o 7. The frequency of positive test results by ELISA within IBH affected horses ranged from 38 % to 67 %. The capability of the allergens to induce Type I hypersensitivity reaction in IBH affected horses was demonstrated by an intradermal test.
The applicability of the 7 C. obsoletus derived recombinant allergens was further evaluated and compared with C. obsoletus WBE in an IgE ELISA using a large number of horses.The highest test accuracy was obtained with WBE, followed by Cul o 2, 3 and 5. Two ELISA’s with a combination of recombinant allergens, combi-1 (Cul o 3, 5 and 7) and combi-2 (Cul o 1, 2, 5 and 7) were additionally performed and both resulted in high test accuracies close to that obtained with WBE. Both combi-1 and combi-2 resulted in a lower test sensitivity with samples collected in winter compared to samples collected in IBH season, but most IBH affected horses could still also be correctly diagnosed in winter.
The association between several factors and IgE levels against C. obsoletus whole body extract and the 7 recombinant allergens was quantified. Furthermore, the relation between IgE levels and severity of symptoms was examined. Severity of symptoms and IgE levels against several C. obsoletus allergens were found to be related. Factors that were found to be associated with IgE levels were: breed, age, month of scoring, interaction between IBH status and month of scoring, degree of itchiness and number of seasons horses were affected with IBH.
The general discussion discussed the prospects to use the produced recombinant allergens for immunotherapy treatment of IBH affected horses. The panel of all 7 recombinant allergens allows to determine for which exact components of C. obsoletus the IBH horses are allergic (“component resolved diagnosis”). This will enable a tailor made composition of (recombinant) allergens for use in immunotherapy.
Insect bite hypersensitivity in horses: genetic and epidemiological analysis
Schurink, A. - \ 2012
Wageningen University. Promotor(en): Johan van Arendonk, co-promotor(en): Bart Ducro; Klaas Frankena. - S.l. : s.n. - ISBN 9789461733566 - 168
dierveredeling - overgevoeligheid - paarden - genetische analyse - epidemiologie - insectenbeten - nederland - fries (paardenras) - shetland pony - animal breeding - hypersensitivity - horses - genetic analysis - epidemiology - insect bites - netherlands - frisian (horse breed)
Insect bite hypersensitivity (IBH) is the most common allergic skin disease in horses and is caused by bites of Culicoides spp. IBH reduces welfare of affected horses and at present no effective preventive measure or cure exists. Aim of our research was to increase knowledge of the genetic background of IBH in horse populations and to explore opportunities to reduce IBH prevalence through selection and breeding.
Data on Shetland pony and Friesian horse mares were gathered at obligatory inspections. IBH prevalence was 7.5% in Shetland pony mares and 18.2% in Friesian horse mares. Data were analyzed to identify risk factors. Combined effect of month and year of IBH scoring, region within the Netherlands and inspector were associated with IBH in both breeds. IBH prevalence significantly differed with coat colour and withers height category in Shetland pony mares. Moreover, prevalence was higher in Shetland pony mares with high body condition score (9.4%).
Quantitative genetic analyses revealed substantial genetic variation for IBH in both breeds. Heritability on the observed scale and on the underlying scale was 0.08 and 0.24 respectively in Shetland pony mares, 0.07 and 0.16 respectively in Friesian horse mares. Therefore, IBH is a heritable phenotype in both breeds. Repeatability was 0.30 in Shetland pony mares and 0.89 in Friesian horse mares. Maternal effect (0.17) was estimated in Friesian horse mares only.
To identify genomic regions contributing to the genetic variance, Shetland pony mares and Icelandic horses were selected according to a matched case-control design. Odds ratios of allele substitution effects of the unfavourable allele were between 1.94 and 5.95. Also, 13 and 28% of genetic variance was explained by all SNPs in respectively Shetland pony mares and Icelandic horses. Significant associated genomic regions across breeds suggest interesting candidate regions on ECA3, 7, 11, 20 and 23 contributing to genetic variance. Results support that ELA class II region on ECA20 is involved in IBH etiology, although follow-up studies are needed to confirm this and to identify genes in the other regions.
The general discussion explored possibilities to reduce IBH prevalence through breeding and discussed implications of using clinical symptoms or diagnostic test results. Simulated selection was based on EBV, which included own performance, progeny performance or genomic data. Selection on IBH clinical symptoms should be based on testing at least 10 but preferably more progeny, accompanying strict selection in sires to achieve reasonable genetic gain. Expected genetic gain per year in genomic selection outperformed other strategies, although implementation of genomic selection requires a considerable investment in a reference population. A diagnostic test for IBH (yet unfeasible to perform on a large sample) has the potential to increase genetic gain
Allergieradar: één jaar in de lucht; Overzicht van de eerste resultaten
Vliet, A.J.H. van; Weger, L.A. - \ 2010
Wageningen/Leiden : Wageningen University, Leids Universitair Medisch Centrum
allergieën - overgevoeligheid - hooikoorts - gegevens verzamelen - informatiesystemen - voorlichting - allergies - hypersensitivity - pollen allergy - data collection - information systems - extension
Begin mei 2009 is de website www.allergieradar.nl van start gegaan. Allergieradar.nl is opgericht om patiënten een beeld te geven van de klachten die andere patiënten in Nederland ervaren. Naast deze informatievoorziening worden de symptoomgegevens die patiënten doorgeven gebruikt voor wetenschappelijk onderzoek, zoals het valideren van de hooikoortsverwachting of het ontwikkelen van een nieuwe hooikoortsverwachting voor bijvoorbeeld berkenpollen. In dit verslag wordt een overzicht gegeven van de eerste resultaten van Allergieradar.nl in het eerste jaar.
The impact of food allergy on household level
Voordouw, J. - \ 2010
Wageningen University. Promotor(en): Lynn Frewer; Gerrit Antonides, co-promotor(en): J.R. Cornelisse-Vermaat. - [S.l.] : S.n. - ISBN 9789085857150 - 158
voedselallergieën - overgevoeligheid - kosten - kosten van de gezondheidszorg - sociaal welzijn - etiketteren van voedingsmiddelen - welzijn - food allergies - hypersensitivity - costs - health care costs - social welfare - nutrition labeling - well-being
Adverse reactions to food can be caused by food hypersensitivity. Prominent examples include food allergy or food intolerance. Patients suffering from food hypersensitivity have inappropriate autoimmune system reactions to potentially harmless food components. Symptoms can vary from uncomfortable skin rashes to cardiovascular problems such as anaphylactic shock. To date, no general cure is available. As a consequence, the management of food allergy consists of allergen avoidance, which may cause negative consequences in terms of patient anxiety and their experience of quality of life. Furthermore, implementation of dietary restrictions can have a negative effect on the quality of life and economic functioning of not only the food allergic patient but also their family members.
An important issue in the assessment of the impact of food hypersensitivity and food allergy is the assessment of the economic costs that accrue to afflicted consumers. This information will contribute to the prioritising of healthcare resources, as well as developing effective policies to insure consumer protection. It is also important to evaluate whether wellbeing and welfare are affected. If this is indeed the case, a question arises as how to best manage dietary avoidance strategies. The aim of the research reported in this thesis is to provide information salient to the assessment of the impact of food hypersensitivity and allergy on households with respect to costs (time and money), welfare, well-being, and information search strategies.
A systematic review of the existing literature revealed that researchers had not yet developed and validated an instrument to measure the individual and household costs of food hypersensitivity and/ or allergy. This thesis describes the development of the “household costs of food allergy” questionnaire and the exploratory analyses applied to validate the instrument. Thereafter, the “household costs of food allergy” questionnaire was used on a large sample of clinician-diagnosed food hypersensitive patients to confirm these cost effects. This study was part of an epidemiological study to investigate the prevalence of food allergy and food intolerance in four European countries, data were collected in The Netherlands, Poland, Spain and the United Kingdom. The respondents in this study were either diagnosed with food allergy or food intolerance. For the purposes of this discussion, the term food hypersensitivity will be used to indicate both diseases. Contrary to expectation, households with food hypersensitive respondents had significantly lower direct and indirect costs across all countries compared to households without food hypersensitive members. In addition, no differences in welfare between food hypersensitive respondents and respondents asymptomatic to foods were found. However, adult food hypersensitive respondents and their spouses reported significantly less happiness than respondents, or their spouses, who were asymptomatic. Thus, the results presented in this thesis do not support the commonly held belief of clinical researcher and patient organisations that all food allergies incur high costs to the individual.
Given that an individual’s experience of quality of life is negatively impacted by food hypersensitivity, it is feasible that this might be improved by the implementation of more effective management strategies. As the primary viable management strategy involves avoidance of problematic foods, facilitating consumer choice in the retail environment may optimise risk management. The labelling preferences of food allergic consumers were investigated in two European countries, The Netherlands and Greece. At the time the research was conducted, food legislation had been developed to facilitate management of food allergens in order to protect food allergic consumers, rather than food intolerant consumers. For this reason, the research was confined to the study of the information needs of food allergic patients, and how this related to the current legislative situation. The research utilised ethnographic interviews with food allergic consumers during the course of shopping in a supermarket. The results suggest that current labelling practice is perceived to be inadequate for food allergic consumers if safe food choices are to be made. This is due to inappropriate use of fonts, colours with low contrasts and inconsistencies in the different languages, application of precautionary labelling, and lack of European and international harmonisation in labelling legislation. Based on these results, new information scenarios, such as uniform labelling, information booklet and ICT solutions, were developed and tested through an online survey. The results were used to develop prototype information delivery tools. An experiment was conducted to understand if the information delivery was in fact optimal, and to confirm if the additional attributes of the prototype tools were sufficient to facilitate allergen avoidance. The results suggested that the label should show the percentages of the allergens in the food product, as well as provide specific details about allergy management in the food chain, and use standardised symbols and standardised location of allergy information on the package. Additional visual and auditory warnings were also treated as being important for the ICT driven information delivery approaches, the results indicated that ICT methods are not appropriate replacements for effective food labelling on packaging, but may be used to supplement information provided by labels.
To conclude, this thesis provides insight in the financial impact of food hypersensitivity, as well as the welfare and well-being. The “household costs of food allergy” questionnaire can be used by regulators and policy makers to prioritise healthcare resources, as well as to test the effectiveness of policy interventions. Limitations in current risk management strategies based on consumer information were also identified. The results of the consumer preferences studies can be used by policy makers and food industry to optimise the information delivery to food allergic consumers and therewith improve their quality of life. The combination of economic research and consumer research is relevant to investigate the dynamic impact of food allergy on individuals and their families.
Coeliakie, gluten en de ontwikkeling van granen met verlaagde toxiciteit
Gilissen, L.J.W.J. ; Meer, I.M. van der; Smulders, M.J.M. - \ 2009
Patient Care 12 (2009). - ISSN 0770-4224 - p. 19 - 23.
coeliakie - gluten - tarwegluten - graansoorten - toxiciteit - overgevoeligheid - eiwitten - voeding en gezondheid - voedselintolerantie - coeliac syndrome - wheat gluten - cereals - toxicity - hypersensitivity - proteins - nutrition and health - food intolerance
Coeliakie is een voedingsgerelateerd probleem, veroorzaakt door een overgevoeligheidsreactie op gluten. De diagnose is moeilijk te stellen wegens de grote verscheidenheid aan symptomen. Een levenslang glutenvrij dieet is tot op heden de enige remedie. Gluten is echter een product dat in toenemende mate in een breed scala aan voedingsmiddelen gebruikt wordt, waardoor het steeds moeilijker wordt om gluten te vermijden. Granen met een verlaagde coeliakietoxiciteit kunnen uitkomst bieden.
|Chemical and Biological Properties of Food Allergens
Jedrychowski, L. ; Wichers, H.J. - \ 2009
Boca Raton : CRC Press (Chemical and functional properties of food components ) - ISBN 9781420058550 - 447
voedselallergieën - allergenen - voedsel - overgevoeligheid - food allergies - allergens - food - hypersensitivity
This book provides epidemiological data on food allergens and information on the incidence of food allergies. It discusses the link between hypersensitivity and immune system health and covers methods used for assays on allergenic components, animal models for allergen analysis, and clinical methods for diagnosis. Furthermore, it highlights future trends in applying recombinant food allergens.
|Identification of factors associated with the development of insect bite hypersensitivity in horses in the Netherlands
Boom, R. van den; Ducro, B.J. ; Sloet van Oldruitenborgh-Oosterbaan, M.M. - \ 2008
Tijdschrift voor Diergeneeskunde 133 (2008)13. - ISSN 0040-7453 - p. 554 - 563.
paardenziekten - zomereczeem - insectenbeten - allergieën voor geleedpotigen - overgevoeligheid - paarden - horse diseases - sweet itch - insect bites - arthropod allergies - hypersensitivity - horses - dermatitis sweet itch - british-columbia - culicoides hypersensitivity - dermal hypersensitivity - icelandic horses - genetic-basis - ceratopogonidae - diptera - israel - diseases
An Internet-based questionnaire among horse owners was carried out to identify factors affecting the incidence of insect bite hypersensitivity (IBHI) among horses in the Netherlands. Information was obtained for 794 horses of various breeds, but the breed distribution was not representative for the Dutch horse population. Of the horses for which information was available, 56% suffered from IBH and 44% did not. The most common clinical symptoms were pruritus, scaling, and hair loss, occurring mainly at the base of the tail and along the mane. Breed, age, region (and local habitat), stabling, type of bedding in the stable, use of the horse, deworming frequency, and season were associated with significant differences in IBH incidence. Knowledge of the factors influencing the incidence of IBH may make it possible to reduce the number of animals affected and help alleviate symptoms in affected horses.
Allergie voor dieren : inventarisatie over het voorkomen van allergische reacties bij de mens als gevolg blootstelling aan dierlijke allergenen
Terreehorst, I. ; Willemse, T. ; Heederik, D.J.J. ; Zee, J.S. van der; Groot, H. de; Savelkoul, H.F.J. ; Kerkhoffs, M. ; Wolf, I.D. de - \ 2007
Den Haag : Raad voor Dierenaangelegenheden - 76
dierhouderij - gezelschapsdieren - insecten - allergieën - allergenen - overgevoeligheid - literatuuroverzichten - hobbydieren - mens-dier relaties - animal husbandry - pets - insects - allergies - allergens - hypersensitivity - literature reviews - hobby animals - human-animal relationships
Op grond van een literatuuronderzoek is een top-10 van allergieën voor dieren in Nederland opgesteld
|Hygiënehypothese: een aantrekkelijk concept, maar moeilijk te bewijzen!
Savelkoul, H.F.J. - \ 2007
Voeding Nu 9 (2007)3. - ISSN 1389-7608 - p. 17 - 20.
allergieën - overgevoeligheid - weerstand - auto-immuunziekten - diagnose - tolerantie - ziekteprevalentie - onderzoek - allergies - hypersensitivity - resistance - autoimmune diseases - diagnosis - tolerance - disease prevalence - research
De hygiënhypothese stelt dat de afwezigheid van infecties op de jonge kinderleeftijd gepaard gaat met een zich niet goed ontwikkelend immunoregulatienetwerk. Als gevolg hiervan zou allergische sensibilisatie toenemen en daarmee de kans op allergieën. Deze hypothese is een breed aanvaarde verklaring voor de alom geobserveerde toename van allergie in de Westerse en verwesterde samenlevingen gedurende de laatste 40 jaar. De bewijzen voor deze hypothese zijn echter zeer moeilijk te verkrijgen
Functional analysis of tomato genes expressed during the Cf-4/Avr4-induced hypersensitive response
Gabriëls, S. - \ 2006
Wageningen University. Promotor(en): Pierre de Wit, co-promotor(en): Matthieu Joosten. - [S.l.] : S.n. - ISBN 9085044057 - 144
solanum lycopersicum - tomaten - passalora fulva - genexpressie - verdedigingsmechanismen - overgevoeligheid - ziekteresistentie - virulentie - tomatoes - gene expression - defence mechanisms - hypersensitivity - disease resistance - virulence
Kruisreacties bij voedselallergie
Jeurink, P.V. ; Savelkoul, H.F.J. - \ 2004
Voeding Nu 6 (2004)6. - ISSN 1389-7608 - p. 23 - 26.
voedselallergieën - allergieën - stoornissen samenhangend met voedsel - voedselintolerantie - allergenen - eiwitten - overgevoeligheid - diagnostische technieken - wetenschappelijk onderzoek - food allergies - allergies - food-related disorders - food intolerance - allergens - proteins - hypersensitivity - diagnostic techniques - scientific research
Het hooikoortsseizoen is inmiddels in volle gang. Mensen met hooikoorts hebben vaak ook een voedselallergie. Hun lichaam herkent per abuis de eiwitten, die in voedingsmiddelen voorkomen, zoals stuifmeeleiwitten. Deze kruisreactie is gebaseerd op vergelijkbare structuren van eiwitten of eiwitdomeinen in het uitlokkende allergeen en het allergeen dat een allergische reactie veroorzaakt. Door nieuwe concepten, zoals regulatoire T-cellen, is het mogelijk de achtergronden van de ontwikkeling van allergische klachten en hun onderlinge relaties beter te begrijpen en wellicht nieuwe therapieën te ontwikkelen
|Geïntegreerde benadering van allergieproblematiek noodzakelijk
Wichers, H.J. - \ 2004
Voedingsmiddelentechnologie 37 (2004)7. - ISSN 0042-7934 - p. 28 - 29.
allergieën - overgevoeligheid - preventie - probleemanalyse - voedselindustrie - levensstijl - voedingsgedrag - sociale situatie - wetenschappelijk onderzoek - allergies - hypersensitivity - prevention - problem analysis - food industry - lifestyle - feeding behaviour - social situation - scientific research
Wat moet in de komende jaren de strategie zijn om allergie zo veel mogelijk te voorkomen of beheersbaar te maken en de symptomen te reduceren? Die vraag stond centraal tijdens een internationale conferentie over preventie van allergie georganiseerd door het Allergie Consortium Wageningen. Conclusie was dat de onderzoekers en productontwikkelaars over de grenzen van hun disciplines heen zullen moeten kijken om tot een geïntegreerde benadering van de allergieproblematiek te komen
The molecular basis of co-evolution between Cladosporium fulvum and tomato
Wit, P.J.G.M. de; Brandwagt, B.F. ; Burg, H.A. van den; Cai, X. ; Hoorn, R.A.L. van der; Jong, C.F. de; Klooster, J. van 't; Kock, M.J.D. de; Kruijt, M. ; Lindhout, W.H. ; Luderer, R. ; Takken, F.L.W. ; Westerink, N. ; Vervoort, J.J.M. ; Joosten, M.H.A.J. - \ 2002
Antonie van Leeuwenhoek: : Nederlandsch tijdschrift voor hygiëne, microbiologie en serologie 81 (2002)1-4. - ISSN 0003-6072 - p. 409 - 412.
cladosporium - plantenziekteverwekkers - solanum - genetisch bepaalde resistentie - overgevoeligheid - plant pathogens - genetic resistance - hypersensitivity
Cladosporium fulvum is a semi-biotrophic pathogen, which causes leaf mold of tomato (Lycopersicon spp.). In our laboratory this pathosystem serves as a model to study gene-for-gene interactions between plants and pathogenic fungi (Joosten & De Wit 1999). Many avirulence (Avr) genes and matching resistance (Cf) genes have been cloned and we are now beginning to understand how their products can induce an array of plant defense responses, including the classic hypersensitive response (HR). Here, we will discuss the latest results of our molecular studies on this interaction. These include the isolation of: (i) two new Avr genes, Avr2 and Avr4E, (ii) the determination of the specificity determinants within the Cf-4 and Cf-9 genes by artificial domain swaps and introduction of point mutations, (iii) the analysis of polymorphism occurring in AVR9-responsive Cf genes occurring in natural populations of L. pimpinellifolium, and finally (iv) the description of an efficient method to identify early HR-related genes.
|Assessment of allergenic potential of foods from genetically modified plants
Gilissen, L.J.W.J. ; Nap, J.P.H. - \ 1997
Wageningen : CPRO-DLO - 40
genetische modificatie - recombinant dna - plantkunde - planten - allergieën - allergenen - overgevoeligheid - rapporten - genetic engineering - botany - plants - allergies - allergens - hypersensitivity - reports
Laboratory animal allergy : allergen exposure assessment and epidemiological study of risk factors
Hollander, A. - \ 1997
Agricultural University. Promotor(en): B. Brunekreef; P. Malmberg; D.J.J. Heederik. - S.l. : Hollander - ISBN 9789054857013 - 152
allergieën - overgevoeligheid - laboratoriumdieren - laboratoriummethoden - allergies - hypersensitivity - laboratory animals - laboratory methods
<p>The main objective of the study presented in this thesis was to estimate the prevalence rate of laboratory animal allergy and to determine its association with risk factors, like allergen exposure level, atopy, gender and other host factors. A cross-sectional survey was undertaken among 540 workers at 8 laboratory animal facilities. All participants completed a questionnaire and underwent skin prick testing with common and occupational allergens. Total and specific IgE measures were obtained. Prevalence rates of allergic symptoms (chest tightness (asthma), eye/nose and/or skin) due to working with rats or mice were 19% and 10%, respectively. The most common symptoms were eye/nose symptoms, 17% and 9% and asthmatic symptoms were found in 6% and 3% of the workers, respectively. The prevalence rate of sensitisation to rat or mouse allergens was 18% and I I%. Symptoms and sensitisation were strongly correlated. However, not all symptoms seemed to be IgE mediated. Rat and mouse allergy, defined as allergic symptoms accompanied by sensitisation, was highly associated with elevated total IgE (≥100 kU/1) and positive skin prick response to common allergens. The relationship between rat and mouse allergy and positive skin prick response to common allergens, could be completely explained by a specific response to cat or dog fur allergens.<p>Stationary and personal air sampling was performed to identify determinants of exposure and estimate the animal allergen exposure. Animal caretakers experienced the highest exposure to aeroallergens. However, large variation within each job title was present. This may result from the wide range of tasks performed, of which handling contaminated bedding or conscious rats or mice showed the highest exposure. A relationship between allergen exposure and rat allergy became visible after excluding workers with four or more years of exposure to laboratory animals. This relationship was clearly visible for the atopic workers (having an pet allergy and/or elevated total serum IgE). The effect of exposure on rat allergy varied between atopic and non-atopic workers. Atopy should therefore be considered as an effect modifier of exposure. A higher prevalence rate of rat allergy was also found for men and smokers. However, these associations were not statistically significant.