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Marsella R, White S, Fadok VA, Wilson D, Mueller R, Outerbridge C, Rosenkrantz W. Equine allergic skin diseases: Clinical consensus guidelines of the World Association for Veterinary Dermatology. Vet Dermatol 2023; 34:175-208. [PMID: 37154488 DOI: 10.1111/vde.13168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 02/03/2023] [Accepted: 02/26/2023] [Indexed: 05/10/2023]
Abstract
BACKGROUND Allergic skin diseases are common in horses worldwide. The most common causes are insect bites and environmental allergens. OBJECTIVES To review the current literature and provide consensus on pathogenesis, diagnosis, treatment and prevention. MATERIALS AND METHODS The authors reviewed the literature up to November 2022. Results were presented at North America Veterinary Dermatology Forum (2021) and European Veterinary Dermatology Congress (2021). The report was available to member organisations of the World Association for Veterinary Dermatology for feedback. CONCLUSIONS AND CLINICAL RELEVANCE Insect bite hypersensitivity (IBH) is the best characterised allergic skin disease. An immunoglobulin (Ig)E response against Culicoides salivary antigens is widely documented. Genetics and environmental factors play important roles. Tests with high sensitivity and specificity are lacking, and diagnosis of IBH is based on clinical signs, seasonality and response to insect control. Eosinophils, interleukin (IL)-5 and IL-31 are explored as therapeutic targets. Presently, the most effective treatment is insect avoidance. Existing evidence does not support allergen-specific immunotherapy (ASIT) using commercially available extracts of Culicoides. Hypersensitivity to environmental allergens (atopic dermatitis) is the next most common allergy. A role for IgE is supported by serological investigation, skin test studies and positive response to ASIT. Prospective, controlled, randomised studies are limited, and treatment relies largely on glucocorticoids, antihistamines and ASIT based on retrospective studies. Foods are known triggers for urticaria, yet their role in pruritic dermatitis is unknown. Recurrent urticaria is common in horses, yet our understanding is limited and focussed on IgE and T-helper 2 cell response. Prospective, controlled studies on treatments for urticaria are lacking. Glucocorticoids and antihistamines are primary reported treatments.
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Affiliation(s)
- R Marsella
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
| | - S White
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - V A Fadok
- Zoetis, US PET CARE, Bellaire, Texas, USA
| | - D Wilson
- School of Clinical Veterinary Sciences, University of Bristol, Bristol, UK
| | - R Mueller
- Medizinische Keleintierklinik, Zentrum für klinische Tiermedizin, LMU, Munich, Germany
| | - C Outerbridge
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
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2
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Vostry L, Vostra-Vydrova H, Citek J, Gorjanc G, Curik I. Association of inbreeding and regional equine leucocyte antigen homozygosity with the prevalence of insect bite hypersensitivity in Old Kladruber horse. Anim Genet 2021; 52:422-430. [PMID: 33970495 PMCID: PMC8360196 DOI: 10.1111/age.13075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2021] [Indexed: 12/19/2022]
Abstract
Inbreeding depression is the reduction of performance caused by mating of close relatives. In livestock populations, inbreeding depression has been traditionally estimated by regression of phenotypes on pedigree inbreeding coefficients. This estimation can be improved by utilising genomic inbreeding coefficients. Here we estimate inbreeding depression for insect bite hypersensitivity (IBH) prevalence, the most common allergic horse disease worldwide, in Old Kladruber horse. In a deep pedigree with 3214 horses (187 genotyped), we used a generalised linear mixed model with IBH phenotype from 558 horses examined between 1996 and 2009 (1368 records). In addition to the classical pedigree information, we used the single-step approach that enabled joint use of pedigree and genomic information to estimate inbreeding depression overall genome and equine leucocyte antigen (ELA) class II region. Significant inbreeding depression was observed in all models fitting overall inbreeding coefficients (odds ratio between 1.018 and 1.074, P < 0.05) with the exception of Kalinowski's new inbreeding (P = 0.0516). The increase of ELA class II inbreeding was significantly associated with increased prevalence of IBH (odds ratio 1.018; P = 0.027). However, when fitted jointly with the overall inbreeding coefficient, the effect of ELA class II inbreeding was not significant (odds ratio 1.016; P = 0.062). Overall, the higher ELA class II and/or overall inbreeding (pedigree or genomic) was associated with increased prevalence of IBH in Old Kladruber horses. The single-step approach provides an efficient use of all the available pedigree, genomic, and phenotype information for estimation of overall and regional inbreeding effects.
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Affiliation(s)
- L Vostry
- Czech University of Life Sciences, Kamycka 129, Prague, 16500, Czech Republic
| | - H Vostra-Vydrova
- Czech University of Life Sciences, Kamycka 129, Prague, 16500, Czech Republic.,Institute of Animal Science, Pratelstvi 815, Prague, 10400, Czech Republic
| | - J Citek
- South Bohemia University, Branisovska 31a, Ceske Budejovice, 370 05, Czech Republic.,Veterinary Research Institute, Hudcova 296/70, Brno, 621 00, Czech Republic
| | - G Gorjanc
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, Midlothian, EH259RG, UK
| | - I Curik
- Faculty of Agriculture, University of Zagreb, Svetošimunska cesta 25, Zagreb, 10000, Croatia
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3
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Lindgren G, Naboulsi R, Frey R, Solé M. Genetics of Skin Disease in Horses. Vet Clin North Am Equine Pract 2020; 36:323-339. [PMID: 32534850 DOI: 10.1016/j.cveq.2020.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Equine skin diseases are common, causing increased costs and reduced welfare of affected horses.Genetic testing, if available, can complement early detection, disease diagnosis, and clinical treatment and offers horse breeders the possibility to rule out carrier status. The mechanisms of complex disease can be investigated by using the latest state-of-the-art genomic technologies. Genome-based strategies may also serve as an efficient and cost-effective strategy for the management of the disease severity levels, with particular interest in complex traits such as insect bite hypersensitivity, chronic progressive lymphedema, and melanoma.
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Affiliation(s)
- Gabriella Lindgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Almas Allé 8, Uppsala 75007, Sweden; Livestock Genetics, Department of Biosystems, KU Leuven Leuven, KasteelparkArenberg 30, Leuven 3001, Belgium
| | - Rakan Naboulsi
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Almas Allé 8, Uppsala 75007, Sweden
| | - Rebecka Frey
- AniCura Norsholms Djursjukhus, Norsholm 61791, Sweden
| | - Marina Solé
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Almas Allé 8, Uppsala 75007, Sweden.
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4
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François L, Hoskens H, Velie BD, Stinckens A, Tinel S, Lamberigts C, Peeters L, Savelkoul HFJ, Tijhaar E, Lindgren G, Janssens S, Ducro BJ, Buys N, Schurink AA. Genomic Regions Associated with IgE Levels against Culicoides spp. Antigens in Three Horse Breeds. Genes (Basel) 2019; 10:genes10080597. [PMID: 31398914 PMCID: PMC6723964 DOI: 10.3390/genes10080597] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/25/2019] [Accepted: 08/06/2019] [Indexed: 11/16/2022] Open
Abstract
Insect bite hypersensitivity (IBH), which is a cutaneous allergic reaction to antigens from Culicoides spp., is the most prevalent skin disorder in horses. Misdiagnosis is possible, as IBH is usually diagnosed based on clinical signs. Our study is the first to employ IgE levels against several recombinant Culicoides spp. allergens as an objective, independent, and quantitative phenotype to improve the power to detect genetic variants that underlie IBH. Genotypes of 200 Shetland ponies, 127 Icelandic horses, and 223 Belgian Warmblood horses were analyzed while using a mixed model approach. No single-nucleotide polymorphism (SNP) passed the Bonferroni corrected significance threshold, but several regions were identified within and across breeds, which confirmed previously identified regions of interest and, in addition, identifying new regions of interest. Allergen-specific IgE levels are a continuous and objective phenotype that allow for more powerful analyses when compared to a case-control set-up, as more significant associations were obtained. However, the use of a higher density array seems necessary to fully employ the use of IgE levels as a phenotype. While these results still require validation in a large independent dataset, the use of allergen-specific IgE levels showed value as an objective and continuous phenotype that can deepen our understanding of the biology underlying IBH.
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Affiliation(s)
- Liesbeth François
- Livestock Genetics, Department of Biosystems, KU Leuven, B-3001 Leuven, Belgium
| | - Hanne Hoskens
- Department of Human Genetics, KU Leuven, B-3000 Leuven, Belgium
| | - Brandon D Velie
- School of Life & Environmental Sciences, B19-603 University of Sydney, Sydney, NSW 2006,Australia
| | - Anneleen Stinckens
- Livestock Genetics, Department of Biosystems, KU Leuven, B-3001 Leuven, Belgium
| | - Susanne Tinel
- Livestock Genetics, Department of Biosystems, KU Leuven, B-3001 Leuven, Belgium
| | - Chris Lamberigts
- Research Group Livestock Physiology, Department of Biosystems, KU Leuven, Leuven, B-3001 Leuven, Belgium
| | - Liesbet Peeters
- Biomedical Research Institute, Hasselt University, B-3590 Diepenbeek, Belgium
| | - Huub F J Savelkoul
- Cell Biology and Immunology Group, Wageningen University & Research, 6700 AH Wageningen, The Netherlands
| | - Edwin Tijhaar
- Cell Biology and Immunology Group, Wageningen University & Research, 6700 AH Wageningen, The Netherlands
| | - Gabriella Lindgren
- Livestock Genetics, Department of Biosystems, KU Leuven, B-3001 Leuven, Belgium
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
| | - Steven Janssens
- Livestock Genetics, Department of Biosystems, KU Leuven, B-3001 Leuven, Belgium
| | - Bart J Ducro
- Animal Breeding and Genomics, Wageningen University & Research, 6700 AH Wageningen, The Netherlands
| | - Nadine Buys
- Livestock Genetics, Department of Biosystems, KU Leuven, B-3001 Leuven, Belgium
| | - And Anouk Schurink
- Animal Breeding and Genomics, Wageningen University & Research, 6700 AH Wageningen, The Netherlands.
- Centre for Genetic Resources, The Netherlands (CGN), Wageningen University & Research, 6700 AH Wageningen, The Netherlands.
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5
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Schurink A, da Silva VH, Velie BD, Dibbits BW, Crooijmans RPMA, Franҫois L, Janssens S, Stinckens A, Blott S, Buys N, Lindgren G, Ducro BJ. Copy number variations in Friesian horses and genetic risk factors for insect bite hypersensitivity. BMC Genet 2018; 19:49. [PMID: 30060732 PMCID: PMC6065148 DOI: 10.1186/s12863-018-0657-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 07/19/2018] [Indexed: 12/04/2022] Open
Abstract
Background Many common and relevant diseases affecting equine welfare have yet to be tested regarding structural variants such as copy number variations (CNVs). CNVs make up a substantial proportion of total genetic variability in populations of many species, resulting in more sequence differences between individuals than SNPs. Associations between CNVs and disease phenotypes have been established in several species, but equine CNV studies have been limited. Aim of this study was to identify CNVs and to perform a genome-wide association (GWA) study in Friesian horses to identify genomic loci associated with insect bite hypersensitivity (IBH), a common seasonal allergic dermatitis observed in many horse breeds worldwide. Results Genotypes were obtained using the Axiom® Equine Genotyping Array containing 670,796 SNPs. After quality control of genotypes, 15,041 CNVs and 5350 CNV regions (CNVRs) were identified in 222 Friesian horses. Coverage of the total genome by CNVRs was 11.2% with 49.2% of CNVRs containing genes. 58.0% of CNVRs were novel (i.e. so far only identified in Friesian horses). A SNP- and CNV-based GWA analysis was performed, where about half of the horses were affected by IBH. The SNP-based analysis showed a highly significant association between the MHC region on ECA20 and IBH in Friesian horses. Associations between the MHC region on ECA20 and IBH were also detected based on the CNV-based analysis. However, CNVs associated with IBH in Friesian horses were not often in close proximity to SNPs identified to be associated with IBH. Conclusions CNVs were identified in a large sample of the Friesian horse population, thereby contributing to our knowledge on CNVs in horses and facilitating our understanding of the equine genome and its phenotypic expression. A clear association was identified between the MHC region on ECA20 and IBH in Friesian horses based on both SNP- and CNV-based GWA studies. These results imply that MHC contributes to IBH sensitivity in Friesian horses. Although subsequent analyses are needed for verification, nucleotide differences, as well as more complex structural variations like CNVs, seem to contribute to IBH sensitivity. IBH should be considered as a common disease with a complex genomic architecture. Electronic supplementary material The online version of this article (10.1186/s12863-018-0657-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anouk Schurink
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700, AH, Wageningen, the Netherlands.
| | - Vinicius H da Silva
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700, AH, Wageningen, the Netherlands.,Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, P.O. Box 7023, 75007, Uppsala, Sweden.,Department of Animal Ecology, Netherlands Institute of Ecology, NIOO-KNAW, 6708, PB, Wageningen, the Netherlands
| | - Brandon D Velie
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, P.O. Box 7023, 75007, Uppsala, Sweden
| | - Bert W Dibbits
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700, AH, Wageningen, the Netherlands
| | - Richard P M A Crooijmans
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700, AH, Wageningen, the Netherlands
| | - Liesbeth Franҫois
- KU Leuven, Department of Biosystems, Livestock Genetics, P.O. Box 2456, 3001, Heverlee, Belgium
| | - Steven Janssens
- KU Leuven, Department of Biosystems, Livestock Genetics, P.O. Box 2456, 3001, Heverlee, Belgium
| | - Anneleen Stinckens
- KU Leuven, Department of Biosystems, Livestock Genetics, P.O. Box 2456, 3001, Heverlee, Belgium
| | - Sarah Blott
- Reproductive Biology, Faculty of Medicine and Health Sciences, The University of Nottingham, Leicestershire, LE12 5RD, UK
| | - Nadine Buys
- KU Leuven, Department of Biosystems, Livestock Genetics, P.O. Box 2456, 3001, Heverlee, Belgium
| | - Gabriella Lindgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, P.O. Box 7023, 75007, Uppsala, Sweden
| | - Bart J Ducro
- Animal Breeding and Genomics, Wageningen University & Research, P.O. Box 338, 6700, AH, Wageningen, the Netherlands
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6
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Navas González FJ, Jordana Vidal J, Camacho Vallejo ME, León Jurado JM, de la Haba Giraldo MR, Barba Capote C, Delgado Bermejo JV. Risk factor meta-analysis and Bayesian estimation of genetic parameters and breeding values for hypersensibility to cutaneous habronematidosis in donkeys. Vet Parasitol 2018; 252:9-16. [PMID: 29559159 DOI: 10.1016/j.vetpar.2018.01.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/13/2018] [Accepted: 01/21/2018] [Indexed: 11/19/2022]
Abstract
Cutaneous habronematidosis (CH) is a highly prevalent seasonally recurrent skin disease that affects donkeys as a result from the action of spirurid stomach worm larvae. Carrier flies mistakenly deposit these larvae on previous skin lesions or on the moisture of natural orifices, causing distress and inflicting relapsing wounds to the animals. First, we carried out a meta-analysis of the predisposing factors that could condition the development of CH in Andalusian donkeys. Second, basing on the empirical existence of an inter and intrafamilial variation previously addressed by owners, we isolated the genetic background behind the hypersensibility to this parasitological disease. To this aim, we designed a Bayesian linear model (BLM) to estimate the breeding values and genetic parameters for the hypersensibility to CH as a way to infer the potential selection suitability of this trait, seeking the improvement of donkey conservation programs. We studied the historical record of the cases of CH of 765 donkeys from 1984 to 2017. Fixed effects included birth year, birth season, sex, farm/owner, and husbandry system. Age was included as a linear and quadratic covariate. Although the effects of birth season and birth year were statistically non-significant (P > 0.05), their respective interactions with sex and farm/owner were statistically significant (P < 0.01), what translated into an increase of 40.5% in the specificity and of 0.6% of the sensibility of the model designed, when such interactions were included. Our BLM reported highly accurate genetic parameters as suggested by the low error of around 0.005, and the 95% credible interval for the heritability of ±0.0012. The CH hypersensibility heritability was 0.0346. The value of 0.1232 for additive genetic variance addresses a relatively low genetic variation in the Andalusian donkey breed. Our results suggest that farms managed under extensive husbandry conditions are the most protective ones against developing CH. Furthermore, these results provide evidence of the lack of repercussion of other factors such as age or sex. Potentially considering CH hypersensibility as a negative selection aimed goal in donkey breeding programs, may turn into a measure to improve animal welfare indirectly. However, the low heritability value makes it compulsory to control environmental factors to ensure the effectiveness of the breeding measures implemented to obtain individuals that may genetically be less prone to develop the condition.
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Affiliation(s)
- Francisco Javier Navas González
- Department of Genetics, Faculty of Veterinary Sciences, University of Córdoba, 14071, Córdoba, Spain; The Worldwide Donkey Breeds Project, Faculty of Veterinary Sciences, University of Córdoba, 14071, Córdoba, Spain.
| | - Jordi Jordana Vidal
- Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | | | - Jose Manuel León Jurado
- Centro Agropecuario Provincial de Córdoba, Diputación Provincial de Córdoba, 14071, Córdoba, Spain
| | | | - Cecilio Barba Capote
- Department of Animal Production, Faculty of Veterinary Sciences, University of Córdoba, 14071, Córdoba, Spain
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7
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Lanz S, Brunner A, Graubner C, Marti E, Gerber V. Insect Bite Hypersensitivity in Horses is Associated with Airway Hyperreactivity. J Vet Intern Med 2017; 31:1877-1883. [PMID: 28921663 PMCID: PMC5697210 DOI: 10.1111/jvim.14817] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 05/31/2017] [Accepted: 08/01/2017] [Indexed: 11/29/2022] Open
Abstract
Background Genetic and epidemiologic evidence suggests that in horses, as in other species, different manifestations of hypersensitivity may occur together. Hypothesis Horses affected with insect bite hypersensitivity (IBH) show airway hyperreactivity (AH) to inhaled histamine, even in the absence of overt clinical signs of equine asthma (EA). Animals Twenty‐two healthy controls (group C), 24 horses suffering from IBH alone (group IBH), and 23 horses suffering from IBH and EA (group IBH/EA). Methods The clinical histories were assessed using 2 standardized questionnaires, the Horse Owner Assessed Respiratory Signs Index (HOARSI), and IBH scoring. Horses were classified as EA‐affected if their HOARSI was >1 and as IBH‐affected if IBH score was >0. Confounding disorders were excluded by clinical examination. The arterial partial pressure of oxygen (PaO2) was measured and flowmetric plethysmography used to assess airway reactivity to increasing doses of inhaled histamine. Results The median histamine provocation concentration (PC) when ∆flow values increased by 35% (PC35) was significantly higher in group C (5.94 [1.11–26.33] mg/mL) compared to group IBH (2.95 [0.23–10.13] mg/mL) and group IBH/EA (2.03 [0.43–10.94] mg/mL; P < 0.01). The PC50 and PC75 showed very similar differences between groups. Furthermore, PaO2 was significantly lower in group IBH (84 ± 8 mmHg) and group IBH/EA (78 ± 11 mmHg) compared to group C (89 ± 6 mmHg; P < 0.01). Conclusions and Clinical Importance IBH is associated with AH and decreased PaO2, even in the absence of overt respiratory clinical signs.
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Affiliation(s)
- S Lanz
- Swiss Institute of Equine Medicine, University of Bern and Agroscope, Berne, Switzerland
| | - A Brunner
- Swiss Institute of Equine Medicine, University of Bern and Agroscope, Berne, Switzerland
| | - C Graubner
- Swiss Institute of Equine Medicine, University of Bern and Agroscope, Berne, Switzerland
| | - E Marti
- Department of Clinical Research, University of Bern, Berne, Switzerland
| | - V Gerber
- Swiss Institute of Equine Medicine, University of Bern and Agroscope, Berne, Switzerland
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8
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Citek J, Vostry L, Vostra-Vydrova H, Brzakova M, Prantlova V. Genetic parameters of insect bite hypersensitivity in the Old Grey Kladruber horse. J Anim Sci 2017; 95:53-58. [PMID: 28177358 DOI: 10.2527/jas.2016.0745] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The objective of this study was to assess the genetic parameters of insect bite hypersensitivity (IBH) in the Old Grey Kladruber horse, an original Czech warmblood horse breed. Insect bite hypersensitivity is a recurrent allergic skin disease affecting horses worldwide. Its etiology is multifactorial. The defect is genetically controlled, and the starting impulse is a bite by midges of the spp. and less frequently spp. Knowledge about the associated genes is limited. Horses were kept by the National Stud in Kladruby (1,146 measurements) and by 10 private breeders (63 measurements). The horses were visually scored by the same inspector over a period of 13 yr from 1996 to 2009. A linear logistic model with a binary variable was used for subsequent statistical analysis. The fixed effects of the farm, year of evaluation, age of evaluation, and sex were significant, and the nonsignificant effect was the intensity of greying. The animals from the National Stud were more strongly affected by IBH than animals from private studs. The National Stud is located near the Labe River, at an altitude of 206 m; there are bottomland pastures in the vicinity, blind river arms, and numerous pools and marshes, and the climate is mild. These conditions are convenient for horse keeping but also for the propagation of . The stallions were less affected than the mares. The occurrence in years of age was influenced by selection; scoring began in the first year of age, and when the young animal was repeatedly positive, it was eliminated from breeding. The estimated h differed significantly from 0, and the direct h were 0.626 in the animal model with a maternal effect, 0.359 in the animal model without a maternal effect, and 0.363 in the animal model without correlation between direct and maternal effect. The maternal h was 0.305. The estimated repeatabilities were 0.636 with a maternal effect, 0.615 without a maternal effect, and 0.623 without correlation. The h of IBH was found to be medium to high, so there is a possibility to reduce the prevalence of IBH by selection.
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9
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Velie BD, Shrestha M, Franҫois L, Schurink A, Tesfayonas YG, Stinckens A, Blott S, Ducro BJ, Mikko S, Thomas R, Swinburne JE, Sundqvist M, Eriksson S, Buys N, Lindgren G. Using an Inbred Horse Breed in a High Density Genome-Wide Scan for Genetic Risk Factors of Insect Bite Hypersensitivity (IBH). PLoS One 2016; 11:e0152966. [PMID: 27070818 PMCID: PMC4829256 DOI: 10.1371/journal.pone.0152966] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 03/22/2016] [Indexed: 11/19/2022] Open
Abstract
While susceptibility to hypersensitive reactions is a common problem amongst humans and animals alike, the population structure of certain animal species and breeds provides a more advantageous route to better understanding the biology underpinning these conditions. The current study uses Exmoor ponies, a highly inbred breed of horse known to frequently suffer from insect bite hypersensitivity, to identify genomic regions associated with a type I and type IV hypersensitive reaction. A total of 110 cases and 170 controls were genotyped on the 670K Axiom Equine Genotyping Array. Quality control resulted in 452,457 SNPs and 268 individuals being tested for association. Genome-wide association analyses were performed using the GenABEL package in R and resulted in the identification of two regions of interest on Chromosome 8. The first region contained the most significant SNP identified, which was located in an intron of the DCC netrin 1 receptor gene. The second region identified contained multiple top SNPs and encompassed the PIGN, KIAA1468, TNFRSF11A, ZCCHC2, and PHLPP1 genes. Although additional studies will be needed to validate the importance of these regions in horses and the relevance of these regions in other species, the knowledge gained from the current study has the potential to be a step forward in unraveling the complex nature of hypersensitive reactions.
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Affiliation(s)
- Brandon D. Velie
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
- * E-mail:
| | - Merina Shrestha
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Liesbeth Franҫois
- Research Group Livestock Genetics, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Anouk Schurink
- Animal Breeding and Genomics Centre, Wageningen University, Wageningen, the Netherlands
| | - Yohannes G. Tesfayonas
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anneleen Stinckens
- Research Group Livestock Genetics, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Sarah Blott
- School of Veterinary Medicine & Science, University of Nottingham, Leicestershire, United Kingdom
| | - Bart J. Ducro
- Animal Breeding and Genomics Centre, Wageningen University, Wageningen, the Netherlands
| | - Sofia Mikko
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Ruth Thomas
- Exmoor Pony Society, Cullompton, United Kingdom
| | - June E. Swinburne
- Animal DNA Diagnostics Ltd, Cambridgeshire, United Kingdom
- Animal Health Trust, Newmarket, United Kingdom
| | | | - Susanne Eriksson
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Nadine Buys
- Research Group Livestock Genetics, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Gabriella Lindgren
- Department of Animal Breeding & Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
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10
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Peeters LM, Janssens S, Brebels M, Buys N. Genetic parameters and estimated breeding values of insect bite hypersensitivity in Belgian Warmblood horses. Vet J 2015; 206:420-2. [PMID: 26586216 DOI: 10.1016/j.tvjl.2015.08.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 07/29/2015] [Accepted: 08/09/2015] [Indexed: 10/23/2022]
Abstract
Genetic factors involved in susceptibility to insect bite hypersensitivity (IBH) in Belgian Warmblood horses (BWP) were investigated. Data relating to 3409 horses were collected using a questionnaire, administered to owners during sport competitions, BWP breeding days, breeder visits and after phone calls. Horses were classified as IBH-affected or unaffected, based on two 'disease classifiers': a lifetime record, based on owner information (life_status) and another based on whether or not the horse was showing clinical signs at the time of questioning (clin_status). IBH prevalence was 10% based on life_status, and 6.2% based on clin_status. The heritabilities estimated using threshold animal models varied from 0.65 to 0.78 on the underlying scale (0.18-0.26 on the observed scale). These research findings indicate that susceptibility to IBH is a heritable trait in BWP.
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Affiliation(s)
- Liesbet M Peeters
- Department of Biosystems, Katholieke Universiteit Leuven, BE-3001 Heverlee, Belgium.
| | - Steven Janssens
- Department of Biosystems, Katholieke Universiteit Leuven, BE-3001 Heverlee, Belgium
| | - Machteld Brebels
- Department of Biosystems, Katholieke Universiteit Leuven, BE-3001 Heverlee, Belgium
| | - Nadine Buys
- Department of Biosystems, Katholieke Universiteit Leuven, BE-3001 Heverlee, Belgium
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Shrestha M, Eriksson S, Schurink A, Andersson LS, Sundquist M, Frey R, Broström H, Bergström T, Ducro B, Lindgren G. Genome-Wide Association Study of Insect Bite Hypersensitivity in Swedish-Born Icelandic Horses. J Hered 2015; 106:366-74. [PMID: 26026046 DOI: 10.1093/jhered/esv033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 05/08/2015] [Indexed: 12/18/2022] Open
Abstract
Insect bite hypersensitivity (IBH) is the most common allergic skin disease in horses and is caused by biting midges, mainly of the genus Culicoides. The disease predominantly comprises a type I hypersensitivity reaction, causing severe itching and discomfort that reduce the welfare and commercial value of the horse. It is a multifactorial disorder influenced by both genetic and environmental factors, with heritability ranging from 0.16 to 0.27 in various horse breeds. The worldwide prevalence in different horse breeds ranges from 3% to 60%; it is more than 50% in Icelandic horses exported to the European continent and approximately 8% in Swedish-born Icelandic horses. To minimize the influence of environmental effects, we analyzed Swedish-born Icelandic horses to identify genomic regions that regulate susceptibility to IBH. We performed a genome-wide association (GWA) study on 104 affected and 105 unaffected Icelandic horses genotyped using Illumina® EquineSNP50 Genotyping BeadChip. Quality control and population stratification analyses were performed with the GenABEL package in R (λ = 0.81). The association analysis was performed using the Bayesian variable selection method, Bayes C, implemented in GenSel software. The highest percentage of genetic variance was explained by the windows on X chromosomes (0.51% and 0.36% by 73 and 74 mb), 17 (0.34% by 77 mb), and 18 (0.34% by 26 mb). Overlapping regions with previous GWA studies were observed on chromosomes 7, 9, and 17. The windows identified in our study on chromosomes 7, 10, and 17 harbored immune system genes and are priorities for further investigation.
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Affiliation(s)
- Merina Shrestha
- From the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Shrestha, Eriksson, Bergström, and Lindgren); Animal Breeding and Genomic Centre, Wageningen University, 6700 AH Wageningen, The Netherlands (Shrestha, Schurink, and Ducro); Capilet Genetics AB, SE-725 93 Västerås, Sweden (Andersson); Östra Greda Research Group, SE-387 91 Borgholm, Sweden (Sundquist); Norsholms Animal Hospital, SE-602 37 Norrköping, Sweden (Frey); and Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Broström)
| | - Susanne Eriksson
- From the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Shrestha, Eriksson, Bergström, and Lindgren); Animal Breeding and Genomic Centre, Wageningen University, 6700 AH Wageningen, The Netherlands (Shrestha, Schurink, and Ducro); Capilet Genetics AB, SE-725 93 Västerås, Sweden (Andersson); Östra Greda Research Group, SE-387 91 Borgholm, Sweden (Sundquist); Norsholms Animal Hospital, SE-602 37 Norrköping, Sweden (Frey); and Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Broström)
| | - Anouk Schurink
- From the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Shrestha, Eriksson, Bergström, and Lindgren); Animal Breeding and Genomic Centre, Wageningen University, 6700 AH Wageningen, The Netherlands (Shrestha, Schurink, and Ducro); Capilet Genetics AB, SE-725 93 Västerås, Sweden (Andersson); Östra Greda Research Group, SE-387 91 Borgholm, Sweden (Sundquist); Norsholms Animal Hospital, SE-602 37 Norrköping, Sweden (Frey); and Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Broström)
| | - Lisa S Andersson
- From the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Shrestha, Eriksson, Bergström, and Lindgren); Animal Breeding and Genomic Centre, Wageningen University, 6700 AH Wageningen, The Netherlands (Shrestha, Schurink, and Ducro); Capilet Genetics AB, SE-725 93 Västerås, Sweden (Andersson); Östra Greda Research Group, SE-387 91 Borgholm, Sweden (Sundquist); Norsholms Animal Hospital, SE-602 37 Norrköping, Sweden (Frey); and Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Broström)
| | - Marie Sundquist
- From the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Shrestha, Eriksson, Bergström, and Lindgren); Animal Breeding and Genomic Centre, Wageningen University, 6700 AH Wageningen, The Netherlands (Shrestha, Schurink, and Ducro); Capilet Genetics AB, SE-725 93 Västerås, Sweden (Andersson); Östra Greda Research Group, SE-387 91 Borgholm, Sweden (Sundquist); Norsholms Animal Hospital, SE-602 37 Norrköping, Sweden (Frey); and Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Broström)
| | - Rebecka Frey
- From the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Shrestha, Eriksson, Bergström, and Lindgren); Animal Breeding and Genomic Centre, Wageningen University, 6700 AH Wageningen, The Netherlands (Shrestha, Schurink, and Ducro); Capilet Genetics AB, SE-725 93 Västerås, Sweden (Andersson); Östra Greda Research Group, SE-387 91 Borgholm, Sweden (Sundquist); Norsholms Animal Hospital, SE-602 37 Norrköping, Sweden (Frey); and Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Broström)
| | - Hans Broström
- From the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Shrestha, Eriksson, Bergström, and Lindgren); Animal Breeding and Genomic Centre, Wageningen University, 6700 AH Wageningen, The Netherlands (Shrestha, Schurink, and Ducro); Capilet Genetics AB, SE-725 93 Västerås, Sweden (Andersson); Östra Greda Research Group, SE-387 91 Borgholm, Sweden (Sundquist); Norsholms Animal Hospital, SE-602 37 Norrköping, Sweden (Frey); and Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Broström)
| | - Tomas Bergström
- From the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Shrestha, Eriksson, Bergström, and Lindgren); Animal Breeding and Genomic Centre, Wageningen University, 6700 AH Wageningen, The Netherlands (Shrestha, Schurink, and Ducro); Capilet Genetics AB, SE-725 93 Västerås, Sweden (Andersson); Östra Greda Research Group, SE-387 91 Borgholm, Sweden (Sundquist); Norsholms Animal Hospital, SE-602 37 Norrköping, Sweden (Frey); and Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Broström)
| | - Bart Ducro
- From the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Shrestha, Eriksson, Bergström, and Lindgren); Animal Breeding and Genomic Centre, Wageningen University, 6700 AH Wageningen, The Netherlands (Shrestha, Schurink, and Ducro); Capilet Genetics AB, SE-725 93 Västerås, Sweden (Andersson); Östra Greda Research Group, SE-387 91 Borgholm, Sweden (Sundquist); Norsholms Animal Hospital, SE-602 37 Norrköping, Sweden (Frey); and Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Broström)
| | - Gabriella Lindgren
- From the Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Shrestha, Eriksson, Bergström, and Lindgren); Animal Breeding and Genomic Centre, Wageningen University, 6700 AH Wageningen, The Netherlands (Shrestha, Schurink, and Ducro); Capilet Genetics AB, SE-725 93 Västerås, Sweden (Andersson); Östra Greda Research Group, SE-387 91 Borgholm, Sweden (Sundquist); Norsholms Animal Hospital, SE-602 37 Norrköping, Sweden (Frey); and Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden (Broström).
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Sample SH, Fox KM, Wunn D, Roth E, Friedrichs KR. Hematologic and biochemical reference intervals for adult Friesian horses from North America. Vet Clin Pathol 2015; 44:194-9. [DOI: 10.1111/vcp.12248] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Saundra H. Sample
- Department of Pathobiological Sciences; School of Veterinary Medicine; University of Wisconsin-Madison; Madison WI USA
| | | | - Denise Wunn
- IDEXX Laboratories Inc.; North Grafton MA USA
| | | | - Kristen R. Friedrichs
- Department of Pathobiological Sciences; School of Veterinary Medicine; University of Wisconsin-Madison; Madison WI USA
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13
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Wilson AD. Immune responses to ectoparasites of horses, with a focus on insect bite hypersensitivity. Parasite Immunol 2015; 36:560-72. [PMID: 25180696 DOI: 10.1111/pim.12142] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 08/18/2014] [Indexed: 12/24/2022]
Abstract
Horses are affected by a wide variety of arthropod ectoparasites, ranging from lice which spend their entire life on the host, through ticks which feed over a period of days, to numerous biting insects that only transiently visit the host to feed. The presence of ectoparasites elicits a number of host responses including innate inflammatory responses, adaptive immune reactions and altered behaviour; all of which can reduce the severity of the parasite burden. All of these different responses are linked through immune mechanisms mediated by mast cells and IgE antibodies which have an important role in host resistance to ectoparasites, yet immune responses also cause severe pathological reactions. One of the best described examples of such pathological sequelae is insect bite hypersensitivity (IBH) of horses; an IgE-mediated type 1 hypersensitivity to the salivary proteins of Culicoides spp. associated with T-helper-2 production of IL4 and IL13. Importantly, all horses exposed to Culicoides have an expanded population of Culicoides antigen-specific T cells with this pattern of cytokine production, but in those which remain healthy, the inflammatory reaction is tempered by the presence of FoxP3+ CD4+ regulatory T cells that express IL10 and TGF-beta, which suppresses the IL4 production by Culicoides antigen-activated T cells.
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Affiliation(s)
- A D Wilson
- School of Clinical Veterinary Science, University of Bristol, Bristol, UK
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Peeters LM, Schroyen M, Coussé A, De Keyser K, Buys N. Expression of Interleukin-4 Receptor and CCL5 Chemokine is not Related to Insect Bite Hypersensitivity in Horses. J Equine Vet Sci 2013. [DOI: 10.1016/j.jevs.2012.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Raskova V, Citek J. Incidence of Insect Bite Hypersensitivity in a Small Population of Warmblood Horse Breed in the Czech Republic. J Equine Vet Sci 2013. [DOI: 10.1016/j.jevs.2012.07.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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16
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Schurink A, Podesta SC, Ducro BJ, van Arendonk JA, Frankena K. Risk factors for insect bite hypersensitivity in Friesian horses and Shetland ponies in The Netherlands. Vet J 2013; 195:382-4. [DOI: 10.1016/j.tvjl.2012.06.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 06/12/2012] [Accepted: 06/26/2012] [Indexed: 10/28/2022]
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17
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Major histocompatibility complex and other allergy-related candidate genes associated with insect bite hypersensitivity in Icelandic horses. Mol Biol Rep 2012; 40:3333-40. [DOI: 10.1007/s11033-012-2408-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 12/18/2012] [Indexed: 11/25/2022]
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18
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Schurink A, Wolc A, Ducro BJ, Frankena K, Garrick DJ, Dekkers JCM, van Arendonk JAM. Genome-wide association study of insect bite hypersensitivity in two horse populations in the Netherlands. Genet Sel Evol 2012; 44:31. [PMID: 23110538 PMCID: PMC3524047 DOI: 10.1186/1297-9686-44-31] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 10/19/2012] [Indexed: 01/09/2023] Open
Abstract
Background Insect bite hypersensitivity is a common allergic disease in horse populations worldwide. Insect bite hypersensitivity is affected by both environmental and genetic factors. However, little is known about genes contributing to the genetic variance associated with insect bite hypersensitivity. Therefore, the aim of our study was to identify and quantify genomic associations with insect bite hypersensitivity in Shetland pony mares and Icelandic horses in the Netherlands. Methods Data on 200 Shetland pony mares and 146 Icelandic horses were collected according to a matched case–control design. Cases and controls were matched on various factors (e.g. region, sire) to minimize effects of population stratification. Breed-specific genome-wide association studies were performed using 70 k single nucleotide polymorphisms genotypes. Bayesian variable selection method Bayes-C with a threshold model implemented in GenSel software was applied. A 1 Mb non-overlapping window approach that accumulated contributions of adjacent single nucleotide polymorphisms was used to identify associated genomic regions. Results The percentage of variance explained by all single nucleotide polymorphisms was 13% in Shetland pony mares and 28% in Icelandic horses. The 20 non-overlapping windows explaining the largest percentages of genetic variance were found on nine chromosomes in Shetland pony mares and on 14 chromosomes in Icelandic horses. Overlap in identified associated genomic regions between breeds would suggest interesting candidate regions to follow-up on. Such regions common to both breeds (within 15 Mb) were found on chromosomes 3, 7, 11, 20 and 23. Positional candidate genes within 2 Mb from the associated windows were identified on chromosome 20 in both breeds. Candidate genes are within the equine lymphocyte antigen class II region, which evokes an immune response by recognizing many foreign molecules. Conclusions The genome-wide association study identified several genomic regions associated with insect bite hypersensitivity in Shetland pony mares and Icelandic horses. On chromosome 20, associated genomic regions in both breeds were within 2 Mb from the equine lymphocyte antigen class II region. Increased knowledge on insect bite hypersensitivity associated genes will contribute to our understanding of its biology, enabling more efficient selection, therapy and prevention to decrease insect bite hypersensitivity prevalence.
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Affiliation(s)
- Anouk Schurink
- Animal Breeding and Genomics Centre, Wageningen University, P,O, Box 338, Wageningen, 6700 AH, the Netherlands
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Reid JM. Predicting evolutionary responses to selection on polyandry in the wild: additive genetic covariances with female extra-pair reproduction. Proc Biol Sci 2012; 279:4652-60. [PMID: 22993252 PMCID: PMC3479734 DOI: 10.1098/rspb.2012.1835] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The evolutionary forces that underlie polyandry, including extra-pair reproduction (EPR) by socially monogamous females, remain unclear. Selection on EPR and resulting evolution have rarely been explicitly estimated or predicted in wild populations, and evolutionary predictions are vulnerable to bias due to environmental covariances and correlated selection through unmeasured traits. However, evolutionary responses to (correlated) selection on any trait can be directly predicted as additive genetic covariances (covA) with appropriate components of relative fitness. I used comprehensive life-history, paternity and pedigree data from song sparrows (Melospiza melodia) to estimate covA between a female's liability to produce extra-pair offspring and two specific fitness components: relative annual reproductive success (ARS) and survival to recruitment. All three traits showed non-zero additive genetic variance. Estimates of covA were positive, predicting evolution towards increased EPR, but 95% credible intervals overlapped zero. There was therefore no conclusive prediction of evolutionary change in EPR due to (correlated) selection through female ARS or recruitment. Negative environmental covariance between EPR and ARS would have impeded evolutionary prediction from phenotypic selection differentials. These analyses demonstrate an explicit quantitative genetic approach to predicting evolutionary responses to components of (correlated) selection on EPR that should be unbiased by environmental covariances and unmeasured traits.
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Affiliation(s)
- Jane M Reid
- Institute of Biological and Environmental Sciences, School of Biological Sciences, Zoology Building, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK.
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Schurink A, Ducro BJ, Bastiaansen JWM, Frankena K, van Arendonk JAM. Genome-wide association study of insect bite hypersensitivity in Dutch Shetland pony mares. Anim Genet 2012; 44:44-52. [DOI: 10.1111/j.1365-2052.2012.02368.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2012] [Indexed: 11/30/2022]
Affiliation(s)
- A. Schurink
- Animal Breeding and Genomics Centre; Wageningen University; P.O. Box 338; 6700 AH; Wageningen; the Netherlands
| | - B. J. Ducro
- Animal Breeding and Genomics Centre; Wageningen University; P.O. Box 338; 6700 AH; Wageningen; the Netherlands
| | - J. W. M. Bastiaansen
- Animal Breeding and Genomics Centre; Wageningen University; P.O. Box 338; 6700 AH; Wageningen; the Netherlands
| | - K. Frankena
- Quantitative Veterinary Epidemiology Group; Wageningen University; P.O. Box 338; 6700 AH; Wageningen; the Netherlands
| | - J. A. M. van Arendonk
- Animal Breeding and Genomics Centre; Wageningen University; P.O. Box 338; 6700 AH; Wageningen; the Netherlands
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Schaffartzik A, Hamza E, Janda J, Crameri R, Marti E, Rhyner C. Equine insect bite hypersensitivity: what do we know? Vet Immunol Immunopathol 2012; 147:113-26. [PMID: 22575371 DOI: 10.1016/j.vetimm.2012.03.017] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 02/26/2012] [Accepted: 03/27/2012] [Indexed: 11/29/2022]
Abstract
Insect bite hypersensitivity (IBH) is an allergic dermatitis of the horse caused by bites of insects of the genus Culicoides and is currently the best characterized allergic disease of horses. This article reviews knowledge of the immunopathogenesis of IBH, with a particular focus on the causative allergens. Whereas so far hardly any research has been done on the role of antigen presenting cells in the pathogenesis of IBH, recent studies suggest that IBH is characterized by an imbalance between a T helper 2 (Th2) and regulatory T cell (T(reg)) immune response, as shown both locally in the skin and with stimulated peripheral blood mononuclear cells. Various studies have shown IBH to be associated with IgE-mediated reactions against salivary antigens from Culicoides spp. However, until recently, the causative allergens had not been characterized at the molecular level. A major advance has now been made, as 11 Culicoides salivary gland proteins have been identified as relevant allergens for IBH. Currently, there is no satisfactory treatment of IBH. Characterization of the main allergens for IBH and understanding what mechanisms induce a healthy or allergic immune response towards these allergens may help to develop new treatment strategies, such as immunotherapy.
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Affiliation(s)
- A Schaffartzik
- Swiss Institute of Allergy and Asthma Research-SIAF, University of Zürich, Obere Strasse 22, CH-7270 Davos, Switzerland
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