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Simões J, Tilley P. Decision Making in Severe Equine Asthma-Diagnosis and Monitoring. Animals (Basel) 2023; 13:3872. [PMID: 38136909 PMCID: PMC10740644 DOI: 10.3390/ani13243872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/22/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Decision making consists of gathering quality data in order to correctly assess a situation and determine the best course of action. This process is a fundamental part of medicine and is what enables practitioners to accurately diagnose diseases and select appropriate treatment protocols. Despite severe equine asthma (SEA) being a highly prevalent lower respiratory disease amongst equids, clinicians still struggle with the optimization of routine diagnostic procedures. The use of several ancillary diagnostic tests has been reported for disease identification and monitoring, but many are only suitable for research purposes or lack practicality for everyday use. The aim of this paper is to assist the equine veterinarian in the process of decision making associated with managing SEA-affected patients. This review will focus on disease diagnosis and monitoring, while also presenting a flow-chart which includes the basic data that the clinician must obtain in order to accurately identify severely asthmatic horses in their everyday routine practice. It is important to note that European and American board-certified specialists on equine internal medicine can provide assistance in the diagnosis and treatment plan of SEA-affected horses.
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Affiliation(s)
- Joana Simões
- Equine Health and Welfare Academic Division, Faculty of Veterinary Medicine, Lusófona University, Campo Grande 376, 1749-024 Lisbon, Portugal
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal;
- Associate Laboratory for Animal and Veterinary Sciences (AL4Animals), Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
| | - Paula Tilley
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal;
- Associate Laboratory for Animal and Veterinary Sciences (AL4Animals), Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
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White SD. Approach to the pruritic horse. J Am Vet Med Assoc 2023; 261:S66-S74. [PMID: 36638000 DOI: 10.2460/javma.22.10.0444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/05/2022] [Indexed: 01/14/2023]
Abstract
Pruritus in the horse may be due to several causes, the most common being a hypersensitivity response to salivary proteins in the Culicoides genera, which may coexist with atopic dermatitis, also known as an environmental allergy to pollens, molds, dust, storage mites, etc. Less common etiologies are food allergy and contact allergy, the latter often caused by owners applying various products to the skin. Other ectoparasites, such as Chorioptes mites, may also initiate pruritus. Secondary bacterial infections (usually Staphylococcus spp) may be pruritic in and of themselves. This article reviews the questions that need to be asked of owners to obtain a relevant history, always important for any organ system, but perhaps none more so than the skin. The various clinical findings such as alopecia and crusts and their location on the horse, diagnostic methods such as intradermal or serum testing for allergies, and subsequent hyposensitization are also discussed. Therapeutic options currently available for the potential underlying diseases, in particular for the hypersensitivity reactions to Culicoides spp or environmental allergens, are reviewed with the studies of hyposensitization over the last 40 years, as well as medications that may be effective. While the most common causes of pruritus in the horse are known, the current understanding of the pathophysiology still needs to be investigated, and consequently, the most effective treatments for those causes need to be improved. Newer research is discussed that may eventually add to the diagnostic and therapeutic options currently available for the pruritic horse.
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Affiliation(s)
- Stephen D. White
- School of Veterinary Medicine, University of California-Davis, Davis, CA
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Lo Feudo CM, Stucchi L, Alberti E, Conturba B, Zucca E, Ferrucci F. Intradermal Testing Results in Horses Affected by Mild-Moderate and Severe Equine Asthma. Animals (Basel) 2021; 11:ani11072086. [PMID: 34359214 PMCID: PMC8300230 DOI: 10.3390/ani11072086] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/09/2021] [Accepted: 07/11/2021] [Indexed: 01/21/2023] Open
Abstract
Simple Summary Equine asthma is a respiratory syndrome sharing several similarities with human asthma and represents the most common cause of chronic coughing in horses. Based on the severity and recurrence of the conditions, it is classified as mild-moderate or severe equine asthma. Although a precise pathogenetic mechanism has not yet been identified, it is generally agreed that environmental allergens behave as triggers of a hypersensitivity response (HR), culminating in asthmatic exacerbations. In human medicine, the skin prick test is considered the gold standard of allergy testing; similarly, in equine medicine, intradermal testing is used to identify hypersensitivities to specific allergens. The present study describes and compares the results of intradermal testing in horses affected by either mild-moderate or severe equine asthma to evaluate the responsiveness of asthmatic horses and to identify the most frequently involved allergens. Type-I HR was shown to play a major role in the pathogenesis of severe equine asthma, while type-IV HR seems to be involved mostly in milder forms. Insects represented the antigens inducing the most frequent and strongest reactions among asthmatic horses, followed by Dermatophagoides spp. and dog epithelium; these allergens should therefore be considered for avoidance strategies and the future development of desensitizing allergen-specific immunotherapy. Abstract Equine asthma is an inflammatory respiratory disorder, classified as mild-moderate (MEA) and severe (SEA). SEA is characterized by recurrent exacerbations, consisting of dyspnea, coughing and exercise intolerance; MEA causes poor performance, occasional cough and mucus hypersecretion. Although a precise pathogenesis is not completely understood, allergic mechanisms are considered an important pathophysiological feature of equine asthma. In equine medicine, intradermal testing (IDT) is effective in identifying hypersensitivity to specific allergens. However, to date, the studies about IDT in asthmatic horses obtained contradictory results. This study aims to evaluate IDT responses in MEA and SEA horses and to identify the most significant allergens. Thirty-eight asthmatic horses were enrolled and underwent IDT using 50 allergens; reactions were evaluated at 30 min, 4, 24 and 48 h and were assigned a score from 0 to 4. In SEA horses, the most frequent and strongest reactions were observed at 30 min and 4 h, suggesting the involvement of type I hypersensitivity; in MEA horses, also type IV hypersensitivity seemed to play a major role. Insects, Dermatophagoides spp. and dog epithelium induced in MEA and SEA horses the most significant hypersensitivity responses and could therefore be considered as the main allergenic antigens in our geographic area.
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Affiliation(s)
- Chiara Maria Lo Feudo
- Equine Sports Medicine Laboratory “Franco Tradati”, Department of Veterinary Medicine, Università Degli Studi di Milano, 26900 Lodi, Italy; (C.M.L.F.); (E.A.); (E.Z.)
| | - Luca Stucchi
- Veterinary Teaching Hospital, Università Degli Studi di Milano, 26900 Lodi, Italy; (L.S.); (B.C.)
| | - Elena Alberti
- Equine Sports Medicine Laboratory “Franco Tradati”, Department of Veterinary Medicine, Università Degli Studi di Milano, 26900 Lodi, Italy; (C.M.L.F.); (E.A.); (E.Z.)
| | - Bianca Conturba
- Veterinary Teaching Hospital, Università Degli Studi di Milano, 26900 Lodi, Italy; (L.S.); (B.C.)
| | - Enrica Zucca
- Equine Sports Medicine Laboratory “Franco Tradati”, Department of Veterinary Medicine, Università Degli Studi di Milano, 26900 Lodi, Italy; (C.M.L.F.); (E.A.); (E.Z.)
| | - Francesco Ferrucci
- Equine Sports Medicine Laboratory “Franco Tradati”, Department of Veterinary Medicine, Università Degli Studi di Milano, 26900 Lodi, Italy; (C.M.L.F.); (E.A.); (E.Z.)
- Correspondence: ; Tel.: +39-025-033-4146
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Atopic Dermatitis in Domestic Animals: What Our Current Understanding Is and How This Applies to Clinical Practice. Vet Sci 2021; 8:vetsci8070124. [PMID: 34357916 PMCID: PMC8310319 DOI: 10.3390/vetsci8070124] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/25/2021] [Accepted: 06/26/2021] [Indexed: 12/18/2022] Open
Abstract
Atopic dermatitis is a clinical syndrome that affects both people and animals. Dogs closely mimic the complexity of the human skin disease, and much progress has been made in recent years in terms of our understanding of the role of skin impairment and the identification of new treatments. Cats and horses also develop atopic syndromes which include both cutaneous and respiratory signs, yet studies in these species are lagging. It is now recognized that atopic dermatitis is not a single disease but a multifaceted clinical syndrome with different pathways in various subgroups of patients. Appreciating this complexity is clinically relevant as we develop more targeted treatments which may work well in some patients but not in others. Different phenotypes of atopic dermatitis have been described in dogs, and it is possible that phenotypes related to breed and age may exist in other animals similar to how they are described in people. The awareness of different mechanisms of disease leads to the desire to correlate different phenotypes with specific biomarkers and responses to treatment. In this review, the current understanding and updated information on atopic syndrome in animals are described, highlighting opportunities for further studies in the future.
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Comparison of Four Different Allergy Tests in Equine Asthma Affected Horses and Allergen Inhalation Provocation Test. J Equine Vet Sci 2021; 102:103433. [PMID: 34119204 DOI: 10.1016/j.jevs.2021.103433] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 02/26/2021] [Accepted: 02/27/2021] [Indexed: 11/23/2022]
Abstract
Potential triggers for equine asthma are allergens from hay and straw dusts, mold spores and storage mites. The contribution of these environmental trigger factors to equine asthma is still largely uncertain. The aim of this study was to compare results of four allergy tests from healthy and asthma-affected horses, and to evaluate the clinical relevance of allergens tested positive via specific inhalation provocation test. Fifteen horses were classified using a clinical scoring system as asthmatic (n = 9) or control (n = 6). Four different allergy tests (functional in vitro test, intradermal test, Fc-epsilon receptor test, and ELISA for allergen-specific IgE) were compared. A histamine inhalation provocation test as positive control was performed in all horses and the interpleural pressure was measured. In addition, two individual allergens were chosen for the allergen inhalation provocation test based on the results of the allergy tests and inhaled in increasing concentrations, until signs of dyspnea occurred. None of the four allergy tests could differentiate reliably between controls and asthma-affected horses. There was no agreement among the results of the four allergy tests. The interpleural pressure results showed a large individual variability. A clear positive reaction on the allergen inhalation provocation test was only detected in two asthma-affected horses 6 hours after allergen inhalation with Aspergillus fumigatus and Cladosporium herbarum. In most cases a purely type I immediate reaction is unlikely to be involved in causing the clinical signs of equine asthma. Because of a delayed reaction after allergen provocation in two horses, the involvement of cell-mediated type III or IV hypersensitivity may be possible. As all allergy tests used in this study can only detect IgE-mediated hypersensitivity, these tests are probably not suitable for an etiological diagnosis of equine asthma.
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Lane MJ, Pucheu-Haston CM, Kearney MT, Woodward M. Determination of irritant threshold concentrations of multiple tree, grass, weed and mould allergens for intradermal testing of horses residing in the southern USA. Vet Dermatol 2017; 28:604-e147. [PMID: 28722254 DOI: 10.1111/vde.12472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND Appropriate allergen threshold concentrations (TCs) for intradermal testing (IDT) have not been established in horses for many pollen and mould allergens. OBJECTIVES To determine the TCs in non-allergic horses and describe the frequency of late phase reactions for 26 allergens, including trees, grasses, weeds and moulds in horses residing in the southern Unites States. ANIMALS Twenty four clinically normal horses in the southern United States. METHODS Threshold concentrations for different allergens were determined using IDT subjective measurements at 30 minutes. Delayed reactions were evaluated at 4 and 24 h. RESULTS Threshold concentrations (all PNU/mL) were established for eight tree allergens (black willow 1,000, box elder 1,000, live oak 1,000, pecan 2,000, white ash 4,000, red oak 4,000, red mulberry 2,000 and green ash 2,000); two grass allergens (Johnson grass 250 PNU/mL and Kentucky blue grass 500 PNU/mL); two weeds (carelessweed 1,000 PNU/mL, great ragweed 500 PNU/mL) and one mould (Curvularia 8,000 PNU/mL). The TC was not determined due to excessive reactivity at the lowest concentration tested (1,000 PNU/mL) for bahia and perennial rye grass. Eleven other allergens did not meet the criteria to establish a TC when evaluated at 30 min due to lack of positive reactions. Multiple allergens caused positive reactions in ≥10% of horses at 4 h. Reactions at 24 h were rare with the exception of one horse. CONCLUSIONS AND CLINICAL IMPORTANCE This study identified intradermal TC for multiple pollen and mould allergens in horses. These values may prove useful for optimizing allergen concentrations for IDT of allergic horses.
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Affiliation(s)
- Martha J Lane
- Veterinary Clinical Sciences, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, LA, 70803, USA
| | - Cherie M Pucheu-Haston
- Veterinary Clinical Sciences, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, LA, 70803, USA
| | - Michael T Kearney
- Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, LA, 70803, USA
| | - Michelle Woodward
- Veterinary Clinical Sciences, Louisiana State University School of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, LA, 70803, USA
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Affiliation(s)
- S. D. White
- Department of Medicine and Epidemiology; School of Veterinary Medicine; University of California; Davis USA
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8
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Woodward MC, Andrews FM, Kearney MT, Del Piero F, Hammerberg B, Pucheu-Haston CM. Characterization of IgE-mediated cutaneous immediate and late-phase reactions in nonallergic horses. Am J Vet Res 2014; 75:633-41. [PMID: 24959729 DOI: 10.2460/ajvr.75.7.633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To characterize the response of skin of nonallergic horses following ID injection of polyclonal rabbit anti-canine IgE (anti-IgE) and rabbit IgG. ANIMALS 6 healthy horses. PROCEDURES Skin in the cervical area was injected ID with anti-IgE and IgG. Wheal measurements and skin biopsy specimens were obtained before and 20 minutes and 6, 24, and 48 hours after injection. Tissue sections were evaluated for inflammatory cells at 4 dermal depths. Immunohistochemical analysis for CD3, CD4, and CD8 was performed, and cell counts were evaluated. RESULTS Anti-IgE wheals were significantly larger than IgG wheals at 20 minutes and 6 and 24 hours after injection. There were significantly more degranulated mast cells after anti-IgE injection than after IgG injection. There were significantly more eosinophils at 6, 24, and 48 hours and neutrophils at 6 hours after anti-IgE injection, compared with cell numbers at those same times after IgG injection. There were significantly more eosinophils in the deeper dermis of anti-IgE samples, compared with results for IgG samples. No significant differences between treatments were detected for CD3(+), CD4(+), or CD8(+) cells. CONCLUSIONS AND CLINICAL RELEVANCE Injection of anti-IgE antibodies was associated with the development of gross and microscopic inflammation characterized by mast cell degranulation and accumulation of inflammatory cells, particularly eosinophils and neutrophils. This pattern appeared to be similar to that of horses with naturally developing allergic skin disease, although lymphocytes were not increased; thus, ID injection of anti-IgE in horses may be of use for evaluating allergic skin diseases of horses.
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Affiliation(s)
- Michelle C Woodward
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803
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Pirie RS. Recurrent airway obstruction: a review. Equine Vet J 2014; 46:276-88. [PMID: 24164473 DOI: 10.1111/evj.12204] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 10/05/2013] [Indexed: 12/01/2022]
Abstract
Recurrent airway obstruction is a widely recognised airway disorder, characterised by hypersensitivity-mediated neutrophilic airway inflammation and lower airway obstruction in a subpopulation of horses when exposed to suboptimal environments high in airborne organic dust. Over the past decade, numerous studies have further advanced our understanding of different aspects of the disease. These include clarification of the important inhaled airborne agents responsible for disease induction, improving our understanding of the underlying genetic basis of disease susceptibility and unveiling the fundamental immunological mechanisms leading to establishment of the classic disease phenotype. This review, as well as giving a clinical overview of recurrent airway obstruction, summarises much of the work in these areas that have culminated in a more thorough understanding of this debilitating disease.
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Affiliation(s)
- R S Pirie
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Roslin, Midlothian, UK
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In vitro bioassay to detect reaginic antibodies from the serum of horses affected with Recurrent Airway Obstruction. Vet Res Commun 2009; 34:91-9. [DOI: 10.1007/s11259-009-9334-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2009] [Indexed: 10/20/2022]
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Wagner B, Miller WH, Erb HN, Lunn DP, Antczak DF. Sensitization of skin mast cells with IgE antibodies to Culicoides allergens occurs frequently in clinically healthy horses. Vet Immunol Immunopathol 2009; 132:53-61. [PMID: 19836083 DOI: 10.1016/j.vetimm.2009.09.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IgE antibodies are mediators of mast cell degranulation during allergic diseases. The binding of IgE to its high-affinity IgE receptor on mast cell surfaces is called "sensitization" and precedes the development of clinical allergy. Previously, intradermal injection of anti-IgE or the anti-IgG(T) antibody CVS40 induced immediate skin reactions in horses. This suggested that both IgE and IgG(T) sensitize equine skin mast cells. Here, we investigated sensitization to allergen and with IgE or IgG(T) in clinically healthy horses of different age groups. In addition, immediate skin reactions to Culicoides were determined by intradermal testing in non-allergic horses. A total of 14% of the young horses 1-3 years old and 38% of the adult animals showed skin reaction to Culicoides allergen extract. Sensitization with IgE and IgG(T) was evaluated in skin mast cells and peripheral blood basophils to determine whether sensitization with IgG(T) preceded that with IgE in young horses. Anti-IgE stimulated immediate skin reactions in 18 of 21 young horses, but only 7 of them reacted to the anti-IgG(T) antibody CVS40. The equine IgG(T) fraction is composed of IgG3 and IgG5. We used several newly developed monoclonal antibodies to IgG3 and IgG5 for intradermal testing to improve our understanding about the mast cell reaction induced by the anti-IgG(T) antibody CVS40. None of these antibodies induced a skin reaction in young or adult horses. To determine sensitization with IgE in neonates and foals at 6 and 12 weeks of age an in vitro histamine release assay was performed using peripheral blood cells. The histamine concentration released by anti-IgE stimulation from foal basophils increased between birth and 12 weeks of age, while almost no histamine release was observed after anti-IgG(T) treatment of the cells. In summary, IgE was the major immunoglobulin involved in the sensitization of mast cells and basophils in horses at various ages. IgG(T) antibodies did not play a major role in the activation of mast cells or basophils in young horses and their role in the sensitization of adult horses remains unclear. Sensitization to Culicoides allergen in the absence of clinical disease was frequently found in horses of all age groups. Because many clinically healthy horses developed skin reactions to this allergen, sensitization results are useful to diagnose Culicoides-induced allergy only in horses with allergic conditions.
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Affiliation(s)
- Bettina Wagner
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
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In vitro allergy tests compared to intradermal testing in horses with recurrent airway obstruction. Vet Immunol Immunopathol 2008; 127:85-93. [PMID: 19027178 DOI: 10.1016/j.vetimm.2008.09.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 09/19/2008] [Accepted: 09/24/2008] [Indexed: 11/23/2022]
Abstract
Recurrent airway obstruction (RAO) is a common condition in stabled horses characterised by small airway inflammation, airway neutrophilia and obstruction following exposure of susceptible horses to mouldy hay and straw and is thus regarded as a hypersensitivity reaction to mould spores. However, the role of IgE-mediated reactions in RAO remains unclear. The aim of the study was to investigate with a serological IgE ELISA test (Allercept), an in vitro sulfidoleukotriene (sLT) release assay (CAST) and with intradermal testing (IDT) whether serum IgE and IgE-mediated reactions against various mould, mite and pollen extracts are associated with RAO. IDT reactions were evaluated at different times in order to detect IgE-mediated immediate type reactions (type I hypersensitivity reactions, 0.5-1 h), immune complex-mediated late type reactions (type III reactions, 4-10 h) and cell-mediated delayed type reactions (type IV hypersensitivity reactions 24-48 h). In the serological test, overall the control horses displayed more positive reactions than the RAO-affected horses but the difference was not significant. Comparison of the measured IgE levels showed that the RAO-affected horses had slightly higher IgE levels against Aspergillus fumigatus than controls (35 and 16 AU, respectively, p<0.05), but all values were below the cut off (150 AU) of the test. In the sLT release assay, seven positive reactions were observed in the RAO-affected horses and four in the controls but this difference was not significant. A significantly higher proportion of late type IDT reactions was observed in RAO-affected horses compared to controls (25 of 238 possible reactions versus 12 of 238 possible reactions, respectively, p<0.05). Interestingly, four RAO-affected but none of the control horses reacted with the recombinant mould allergen A. fumigatus 8 (rAsp f 8, p<0.05), but only late phase and delayed type reactions were observed. In all three tests the majority of the positive reactions was observed with the mite extracts (64%, 74% and 88% of all positive reactions, respectively) but none of the tests showed a significant difference between RAO-affected and control animals. Our findings do not support that IgE-mediated reactions are important in the pathogenesis of RAO. Further studies are needed to investigate whether sensitisation to mite allergens is of clinical relevance in the horse and to understand the role of immune reactions against rAsp f 8.
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Marinkovic D, Aleksic-Kovacevic S, Plamenac P. Cellular basis of chronic obstructive pulmonary disease in horses. ACTA ACUST UNITED AC 2007; 257:213-47. [PMID: 17280899 DOI: 10.1016/s0074-7696(07)57006-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Chronic obstructive pulmonary disease (COPD) is an inflammatory obstructive disease of the airways characterized with hypersensitivity of the airway tissues to various allergens, most commonly the fungi contained in the poor-quality hay and straw bedding-Saccharopolyspora rectivirgula, Aspergillus fumigatus, and Thermoactinomyces vulgaris. It is manifested clinically in middle-aged horses with recurrent episodes of dyspnea, chronic cough, and their reduced athletic and working capacity. Pulmonary emphysema and lack of pulmonary collapse are the most common gross lesion. Pathohistological findings in horses with COPD are chronic bronchitis/bronchiolitis, with characteristic changes in lumen, mucosa, submucosa, and smooth muscle layer and alveolar emphysema, both distensive and destructive form. Increased immunoreactivity in lungs and tracheobronchial lymph nodes is also noted. Most common lesions seen on cytology imprint smears from tracheal bifurcation is thick, viscous, PAS-positive mucus that forms Curschmann's spirals. Dominant cell population consists of desquamated airway epithelial cells, as well as eosinophils, neutrophils, mast cells, erythrocytes, and alveolar macrophages. Primary pulmonary pathogens as well as potential contaminants and secondary infection agents were isolated bacteriologically from lung samples. All of the aforementioned findings correlate pointing to the fact that chronic bronchitis/bronchiolitis represents a basic substrate of COPD, which have combined inflammatory and immunological etiology, and emphysema is secondary to airway obstruction.
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Affiliation(s)
- Darko Marinkovic
- Department of Pathology, Faculty of Veterinary Medicine, University of Belgrade, Belgrade, Serbia
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Künzle F, Gerber V, Van Der Haegen A, Wampfler B, Straub R, Marti E. IgE-bearing cells in bronchoalveolar lavage fluid and allergen-specific IgE levels in sera from RAO-affected horses. ACTA ACUST UNITED AC 2007; 54:40-7. [PMID: 17359454 DOI: 10.1111/j.1439-0442.2007.00870.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recurrent airway obstruction (RAO) is a common condition in stabled horses characterized by small airway inflammation, airway neutrophilia and obstruction following exposure of susceptible horses to mouldy hay and straw and is thus regarded as a hypersensitivity reaction to mould spores. However, the role of immunoglobulin E antibodies (IgE) in the pathogenesis of RAO is unclear. We hypothesized that the number of cells with receptor-bound IgE in bronchoalveolar lavage fluid (BALF) and IgE levels in serum would be higher in RAO-affected than in healthy horses living in the same environment. Therefore, IgE-positive (+) cells were identified by immunocytochemistry on cytospins from BALF and counted. IgE levels against the mould extracts Aspergillus fumigatus (Asp. f.) and Alternaria alternata (Alt. a.) and the recombinant mould allergen Aspergillus fumigatus 8 (rAsp f 8) were measured by enzyme-linked immunosorbent assay (ELISA) in the sera of seven RAO-affected and 22 clinically healthy mature horses housed in the same conventional stable environment. After correcting for the number of neutrophils, there were no significant differences in IgE+ cells on cytospins from BALF between both groups of horses (5% versus 7%, P > 0.1). Serum IgE levels against the mould extracts were significantly higher in RAO-affected than in clinically healthy horses [median = 119 versus 66 relative ELISA units (REU), P < 0.05]. Furthermore, significantly more RAO-affected than healthy horses had detectable serum IgE against the recombinant allergen rAsp f 8 (4/7 and 3/22, respectively, P < 0.05). Age had no significant effect on BALF cell ratios or on specific serum IgE levels. These results show that high IgE levels against mould antigens are associated with RAO under controlled environmental conditions but ranges of mould-specific serum IgE levels overlapped too much between diseased and clinically healthy animals to be of any diagnostic value. Further studies are needed to assess whether IgE-mediated reactions contribute to the pathogenesis of RAO.
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Affiliation(s)
- F Künzle
- Equine Clinic, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, Länggass-Strasse 124, 3001 Bern, Switzerland
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16
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White SD. Advances in Equine Atopic Dermatitis, Serologic and Intradermal Allergy Testing. ACTA ACUST UNITED AC 2005. [DOI: 10.1053/j.ctep.2005.10.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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Wong DM, Buechner-Maxwell VA, Manning TO, Ward DL. Comparison of results for intradermal testing between clinically normal horses and horses affected with recurrent airway obstruction. Am J Vet Res 2005; 66:1348-55. [PMID: 16173477 DOI: 10.2460/ajvr.2005.66.1348] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate differences in response to ID injection of histamine, phytohemagglutinin (PHA), and Aspergillus organisms between clinically normal horses and horses with recurrent airway obstruction (RAO). ANIMALS 5 healthy adult horses and 5 adult horses with RAO. PROCEDURE Intradermal testing (IDT) was performed on the neck with 2 positive control substances (histamine and PHA) and a mixture comprising 5 Aspergillus species. Four concentrations of each test substance plus a negative control substance were used. Equal volumes (0.1 mL) of each test substance were prepared to yield 15 syringes ([4 concentrations of each test substance plus 1 negative control substance] times 3 test substances) for each side of each horse (ie, 30 syringes/horse). Intradermal injections were administered; diameter of wheals was recorded 0.5, 4, and 24 hours after injection. RESULTS Hypersensitive responses to ID injection of histamine were detected 0.5 hours after injection, and a delay in wheal formation after ID injection of Aspergillus mixture 24 hours after injection was detected in RAO-affected horses but was not observed in clinically normal horses. No differences were detected between the 2 groups after ID injection of PHA. CONCLUSIONS AND CLINICAL RELEVANCE RAO-affected horses are hypersensitive to histamine, suggesting that RAO is associated with a heightened vascular response to histamine. Higher concentrations of Aspergillus mixture may be needed to detect horses that are sensitive to this group of antigens. Wheal reactions to Aspergillus may be a delayed response, suggesting that IDT results should be evaluated 0.5, 4, and 24 hours after ID injection.
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Affiliation(s)
- David M Wong
- Department of Large Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic and State University, Blacksburg, VA 24061-0442, USA
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Wong DM, Buechner-Maxwell VA, Manning TO, Ward DL. Evaluation of the precision of intradermal injection of control substances for intradermal testing in clinically normal horses. Am J Vet Res 2005; 66:1341-7. [PMID: 16173476 DOI: 10.2460/ajvr.2005.66.1341] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the precision of intradermal testing (IDT) in horses. ANIMALS 12 healthy adult horses. PROCEDURE IDT was performed on the neck of each horse by use of 2 positive control substances (histamine and phytohemagglutinin [PHA]) and a negative control substance. An equal volume (0.1 mL) for each injection was prepared to yield a total of 20 syringes ([4 concentrations of each positive control substance plus 1 negative control substance] times 2 positive control substances times 2 duplicative tests) for each side of the neck. Both sides of the neck were used for IDT; therefore, 40 syringes were prepared for each horse. Hair was clipped on both sides of the neck, and ID injections were performed. Diameter of the skin wheals was recorded 0.5, 4, and 24 hours after ID injection. RESULTS Intra- and interhorse skin reactions to ID injection of histamine and PHA resulted in wheals of uniform size at 0.5 and 4 hours, respectively. Significant intra- and interhorse variation was detected in wheals caused by PHA at 24 hours. CONCLUSIONS AND CLINICAL RELEVANCE ID injection of histamine and PHA caused repeatable and precise results at 0.5 and 4 hours, respectively. Concentrations of 0.005 mg of histamine/mL and 0.1 mg of PHA/mL are recommended for use as positive control substances for IDT in horses. This information suggests that consistent wheal size is evident for ID injection of control substances, and variation in wheals in response to ID injection of test antigens results from a horse's immune response to specific antigens.
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Affiliation(s)
- David M Wong
- Department of Large Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic and State University, Blacksburg, VA 24061-0442, USA
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Rüfenacht S, Marti E, von Tscharner C, Doherr MG, Forster U, Welle M, Roosje PJ. Immunoglobulin E-bearing cells and mast cells in skin biopsies of horses with urticaria. Vet Dermatol 2005; 16:94-101. [PMID: 15842539 DOI: 10.1111/j.1365-3164.2005.00440.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The pathogenesis of equine urticaria is not well understood. In man, urticaria has been associated with immunological and nonimmunological mechanisms leading to the release of various mediators by mast cells. Skin biopsies of 32 horses with a history of urticaria were stained with toluidine blue, a double-labelling method for chymase and tryptase, and immunohistochemistry for immunoglobulin (Ig)E. These horses were compared with horses with pemphigus foliaceus, insect bite hypersensitivity and control horses with healthy skin. Neither formalin fixation time nor biopsy site influenced the staining methods. No chymase-positive cells were found. In all groups of horses, cells staining with toluidine blue and for tryptase and IgE were found in the epidermis and hair follicle papilla and significantly more positively staining cells were observed in the subepidermal dermis compared with the deep dermis. Horses with urticaria had significantly more IgE-bearing cells in the subepidermal dermis than control horses. However, horses with urticaria had significantly fewer toluidine-blue-stained mast cells in both subepidermal and deep dermis compared with the insect bite hypersensitivity and pemphigus foliaceus groups. This study suggests that IgE-mediated reactions play a role in the pathogenesis of urticaria.
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Affiliation(s)
- Silvia Rüfenacht
- Dermatology Unit, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Switzerland.
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O Morris D, Lindborg S. Determination of 'irritant' threshold concentrations for intradermal testing with allergenic insect extracts in normal horses. Vet Dermatol 2003; 14:31-36. [PMID: 12603683 DOI: 10.1046/j.1365-3164.2003.00322.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Sixteen healthy horses with no history of skin or respiratory disease were used for an intradermal testing (IDT) threshold study, in order to determine the concentrations of 13 commercial allergenic insect extracts most appropriate for IDT. Five dilutions of each extract were used, which included the manufacturer's recommended concentrations for equine IDT, plus one dilution higher and three lower than these standard concentrations. Allergens tested included caddisfly (Trichoptera spp.), mayfly (Ephemeroptera spp.), horsefly (Tabanus spp.), deerfly (Chrysops spp.), fire ant (Solenopsis invicta), black ant (Camponotus pennsylvanicus), cockroach mix (Periplaneta americana and Blattella germanica), mosquito (Aedes aegypti), house fly (Musca domestica), moth (Heterocera spp.), flea (Ctenocephalides canis/C. felis), Culicoides variipennis and Culicoides nubeculosis. Two separate methods were used to calculate the allergen concentration for each insect extract where the normal horses, as a group, ceased to show false-positive ('irritant') reactions. 'Irritant' threshold concentrations were determined for 9/13 of these allergens, whereas the other 4 were undetermined due to either insufficient reactivity (flea, C. variipennis) or excessive reactivity (black ant, moth) to the concentrations tested. Recommended concentrations for future use in equine patients with suspected insect hypersensitivity include: 125 pnu mL(-1) (mayfly); 250 pnu mL(-1) (caddisfly, horsefly, deerfly, fire ant, house fly); 500 pnu mL(-1) (cockroach); 1000 pnu mL(-1) (mosquito); and 1:10 000 w/v (C. nubeculosis).
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Affiliation(s)
| | - Susan Lindborg
- Department of Clinical Studies - New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Lebis C, Bourdeau P, Marzin-Keller F. Intradermal skin tests in equine dermatology: a study of 83 horses. Equine Vet J 2002; 34:666-71. [PMID: 12455836 DOI: 10.2746/042516402776250469] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Allergic diseases are often diagnosed clinically in the horse without performing diagnostic tests. The purpose of this work was to contribute to the validation of intradermal skin tests in the horse. Eighty-three horses, 14 showing skin or respiratory signs of supposed allergic origin, were subjected to an intradermal skin test using 6 different allergens, positive and negative controls. The tests were read for all animals after 20 min, and for 29 horses after 1 and 4 h. Additionally, 19 horses were tested a few months apart. The comparison after 20 min of the cutaneous reactions to allergens and to positive and negative controls allowed us to propose a threshold of positivity; skin reactions with a diameter above or equal to 15 mm, or with at least a 13 mm diameter and a skin thickness similar to the positive control. There was a marked difference between the healthy group and the allergic group for Culex pipiens and Dermatophagoides farinae, although positive reactions were not rare in the healthy group. Tabanus sp. gave positive reactions in both healthy and allergic animals. There was no significant variation in the reactions observed after 20 min and after 60 min. After 4 h, the progression of the reactions was highly variable and negative controls showed a certain number of positive reactions, which negated their reliability at the point in time, and made it difficult to interpret the other allergens. Finally, the repeatability of intradermal skin tests reactions after 20 min was poor, and probably related to the influence of seasonality for some of the allergens. Further studies are required, notably with others allergens, to interpret intradermal skin tests' responses in clinical practice.
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Affiliation(s)
- C Lebis
- Clinique Vétérinaire, Pont-L'Abbé, France
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Lorch G, Hillier A, Kwochka KW, Saville WJ, Kohn CW, LeRoy BE. Comparison of immediate intradermal test reactivity with serum IgE quantitation by use of a radioallergosorbent test and two ELISA in horses with and without atopy. J Am Vet Med Assoc 2001; 218:1314-22. [PMID: 11330620 DOI: 10.2460/javma.2001.218.1314] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare a radioallergosorbent test and 2 ELISA with intradermal testing for the determination of environmental allergen hypersensitivity in horses with and without atopic diseases. DESIGN Prospective clinical study. ANIMALS 10 horses with recurrent urticaria, 7 with atopic dermatitis, 16 with chronic obstructive pulmonary disease, and 22 without atopy. PROCEDURE History, physical examination, hemogram, serum biochemical analyses, bronchoalveolar lavage, and an intradermal test (used as the criterion standard) with a regional panel of 73 allergens were performed in all horses. Serum was analyzed by use of the 3 in vitro assays of allergen-specific IgE. RESULTS An ELISA based on the alpha chain of the high-affinity IgE receptor, the Fcepsilon receptor immunoglobin epsilon chain (FcepsilonRIalpha) for IgE, had the overall highest kappa statistic (0.238), positive predictive value (49%), and negative predictive value (78%). Overall agreement between the FcepsilonRIalpha-based ELISA and the intradermal test was fair. The highest kappa statistic was obtained by the FcepsilonRIalpha-based ELISA in horses with atopic dermatitis (0.330). Kappa statistics for the radioallergosorbent test and a polyclonal antibody-based ELISA agreed slightly with that of the intradermal test at best. CONCLUSIONS AND CLINICAL RELEVANCE None of the 3 serum allergy tests reliably detected allergen hypersensitivity, compared with the intradermal test. The FcepsilonRIalpha-based ELISA performed significantly better overall than the other 2 tests. Low sensitivity of all 3 assays indicates the need for continued study to elucidate a more sensitive test for the determination of potentially pathogenic allergens in horses.
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Affiliation(s)
- G Lorch
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210-1092, USA
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