Prevalence of serum immunoglobulin E against cross-reactive carbohydrate determinants in allergic and nonallergic horses, and its impact on polysensitisation in serum allergen tests.

BACKGROUND: The existence of antibodies against cross-reactive carbohydrate determinants (CCDs) has been studied extensively in humans, and more recently, in dogs and cats. These antibodies can reduce the specificity of in vitro serum allergen tests. OBJECTIVES: To investigate the prevalence of anti-CCD immunoglobulin (Ig)E in both allergic and nonallergic horses as well as evaluate its potential impact on serum allergen testing. ANIMALS: Twenty-one allergic and 21 nonallergic horses. METHODS AND MATERIALS: Sera were analysed for anti-CCD IgE utilising a commercial CHO enzyme-linked immunosorbent assay (ELISA). An allergen specific Fc-ε receptor ELISA then was performed to evaluate polysensitisation, both with and without the addition of a proprietary anti-CCD blocking solution. RESULTS: Antibodies against CCD were detected in 30 of 42 horses. There was no statistically significant difference (p = 0.18) between the allergic and healthy groups in regard to anti-CCD prevalence. Horses with anti-CCD IgE exhibited more polysensitisation on serum allergen tests than horses without anti-CCD IgE in all allergen groups except mites. Polysensitisation was statistically significant at the 95% confidence interval for grasses (p <0.03), weeds (p = 0.02) and stinging insects (p = 0.0005). This was found to be true across both study groups. Inhibition with an anti-CCD blocking solution resulted in a 43% average reduction in polysensitisation. CONCLUSION AND CLINICAL IMPORTANCE: The prevalence of anti-CCD IgE of horses in this study coincides with the prevalence detected in pollen-sensitised people. Horses with anti-CCD IgE exhibited more positive reactions on serum allergen tests. By minimising potential artifactual polysensitisation, inclusion of an anti-CCD blocker may facilitate identification of allergen-specific IgE.

Contexte - L'existence d'anticorps contre les déterminants glucidiques à réaction croisée (CCD) a été largement étudiée chez l'homme et, plus récemment, chez le chien et le chat. Ces anticorps peuvent réduire la spécificité des tests d'allergènes sériques in vitro. Objectifs - Étudier la prévalence de l'immunoglobuline anti-CCD (Ig)E chez les chevaux allergiques et non allergiques et évaluer son impact potentiel sur les tests d'allergènes sériques. Animaux - Vingt et un chevaux allergiques et 21 chevaux non allergiques. Matériels et méthodes - Les sera ont été analysés pour les IgE anti-CCD en utilisant un dosage immuno-enzymatique CHO commercial (ELISA). Un ELISA du récepteur Fc-ε spécifique à l'allergène a ensuite été réalisé pour évaluer la polysensibilisation, avec et sans l'ajout d'une solution exclusive de blocage anti-CCD. Résultats - Des anticorps anti-CCD ont été détectés chez 30 des 42 chevaux. Il n'y avait pas de différence statistiquement significative (P = 0,18) entre les groupes allergiques et sains en ce qui concerne la prévalence anti-CCD. Les chevaux avec des IgE anti-CCD ont montré plus de polysensibilisation aux tests d'allergènes sériques que les chevaux sans IgE anti-CCD dans tous les groupes d'allergènes à l'exception des acariens. La polysensibilisation était statistiquement significative à l'intervalle de confiance de 95 % pour les graminées (P < 0,03), les herbacées (P = 0,02) et les insectes piqueurs (P = 0,0005). Cela s'est avéré vrai dans les deux groupes d'étude. L'inhibition avec une solution de blocage anti-CCD a entraîné une réduction moyenne de 43 % de la polysensibilisation. Conclusion et importance clinique - La prévalence des IgE anti-CCD des chevaux dans cette étude coïncide avec la prévalence détectée chez les personnes sensibilisées au pollen. Les chevaux avec des IgE anti-CCD ont présenté des réactions plus positives aux tests d'allergènes sériques. En minimisant la polysensibilisation artificielle potentielle, l'inclusion d'un bloqueur anti-CCD peut faciliter l'identification des IgE spécifiques de l'allergène.

Introducción- la existencia de anticuerpos contra los determinantes de carbohidratos de reacción cruzada (CCD) se ha estudiado ampliamente en humanos y, más recientemente, en perros y gatos. Estos anticuerpos pueden reducir la especificidad de las pruebas de alérgenos séricos in vitro. Objetivos - Investigar la prevalencia de inmunoglobulina (Ig)E anti-CCD tanto en caballos alérgicos como no alérgicos, así como evaluar su impacto potencial en las pruebas de alérgenos séricos. Animales- veintiún caballos alérgicos y 21 no alérgicos. Métodos y materiales- los sueros se analizaron para detectar IgE anti-CCD utilizando un ensayo comercial inmunoabsorbente ligado a enzimas (ELISA) para CHO. A continuación, se realizó un ELISA del receptor Fc-ε específico del alérgeno para evaluar la polisensibilización, con y sin la adición de una solución de bloqueo anti-CCD patentada. Resultados- se detectaron anticuerpos contra CCD en 30 de 42 caballos. No hubo diferencia estadísticamente significativa (P = 0,18) entre los grupos alérgicos y sanos con respecto a la prevalencia de anti-CCD. Los caballos con IgE anti-CCD exhibieron más polisensibilización en las pruebas de alérgenos séricos que los caballos sin IgE anti-CCD en todos los grupos de alérgenos excepto los ácaros. La polisensibilización fue estadísticamente significativa en el intervalo de confianza del 95 % para pastos (P < 0,03), malas hierbas (P = 0,02) e insectos picadores (P = 0,0005). Se encontró que esto fue similar en ambos grupos de estudio. La inhibición con una solución de bloqueo anti-CCD resultó en una reducción promedio del 43 % en la polisensibilización. Conclusión e importancia clínica - La prevalencia de IgE anti-CCD de los caballos en este estudio coincide con la prevalencia detectada en personas sensibilizadas al polen. Los caballos con IgE anti-CCD exhibieron más reacciones positivas en las pruebas de alérgenos en suero. La inclusión de un bloqueador anti-CCD puede facilitar la identificación de IgE específica de alérgeno al minimizar la posible polisensibilización artificial.

Contexto - A existência de anticorpos contra determinantes de carboidratos de reação cruzada (CCDs) tem sido estudada extensivamente em humanos, e, mas recentemente, em cães e gatos. Estes anticorpos podem reduzir a especificidade de testes alérgicos sorológicos in vitro. Objetivos - Investigar a prevalência de imunoglobulina (Ig)E tanto em cavalos alérgicos quanto em cavalos não alérgicos e avaliar o seu potencial impacto no teste alérgico sorológico. Animais - Vinte e um cavalos alérgicos e 21 não alérgicos. Métodos e materiais - O soro foi testado para IgE anti-CCD utilizando um ensaio imunoenzimático CHO comercial (ELISA). Um ELISA alérgeno-específico para receptor Fc-ε foi realizado para avaliar polissensibilização, com e sem a adição de uma solução de bloqueio anti-CCD. Resultados - Anticorpos anti-CCD foram encontrados em 30 de 42 cavalos. Não houve diferença estatística significativa (P = 0,18) entre os grupos alérgico e saudável quanto à prevalência de anti-CCD. Cavalos com IgE anti-CCD exibiram mais polissensibilização no teste alérgico sorológico que cavalos sem IgE anti-CCD em todos os grupos alergênicos, exceto ácaros. Polissensibilização foi estatisticamente significativa em um intervalo de confiança de 95% para gramíneas (P < 0,03), herbáceas (P = 0,02) e insetos que picam (P = 0,0005). Isto foi verdadeiro para os dois grupos estudados. Inibição com uma solução bloqueadora de anti-CCD resultou em uma redução média de 43% na polissensibilização. Conclusão e importância clínica - A prevalência de IgE anti-CCD em cavalos nesse estudo coincide com a prevalência detectada em pessoas sensibilizadas a pólen. Equinos com IgE anti-CCD apresentaram mais reações positivas nos testes alérgicos sorológicos. Minimizando uma potencial polissensibilização a partir da utilização de um bloqueador de anti-CCD pode facilitar a identificação de IgE alérgeno-específica.

ABHD5 frameshift deletion in Golden Retrievers with ichthyosis.

Ichthyoses are hereditary skin disorders characterized by the formation of scales and defects in the outermost layer of the epidermis. In dogs, at least six different breed-specific ichthyoses including a relatively common PNPLA1-related autosomal recessive ichthyosis in Golden Retrievers are known. In this study, we investigated 14 Golden Retrievers with scales that were not homozygous for the mutant PNPLA1 allele suggesting a genetically distinct new form of ichthyosis. Histopathological examinations showed lamellar, orthokeratotic hyperkeratosis, and mildly hyperplastic epidermis that led to the diagnosis of a nonepidermolytic ichthyosis. Combined linkage and homozygosity mapping in 14 cases and 30 nonaffected family members delimited a critical interval of ∼12.7 Mb on chromosome 23. Whole-genome sequencing of an affected dog revealed a single protein-changing variant within this region that was not present in 795 control genomes. The identified variant is a 14 bp deletion in the ABHD5 gene (c.1006_1019del), leading to a frameshift and altering the last 14 codons p.(Asp336Serfs*6). The genotypes at this variant showed perfect cosegregation with the ichthyosis phenotype in a large family comprising 14 cases and 72 controls. ABHD5 encodes an acyltransferase required for lipid metabolism. In humans, variants in ABHD5 cause Chanarin-Dorfman syndrome, a neutral lipid storage disease with ichthyosis. Our data in dogs together with the knowledge on the effects of ABHD5 variants in humans strongly suggest ABHD5:c.1006_1019del as candidate causative genetic variant for a new canine form of ichthyosis, which we propose to designate as Golden Retriever ichthyosis type 2 (ICH2).

Leishmania mexicana in a central Texas cat: clinical presentation, molecular identification, sandfly vector collection and novel management.

CASE SUMMARY: This case report documents the clinical appearance, diagnosis and novel treatment of a central Texas cat with cutaneous leishmaniosis. The cat presented with a linear erosion on the right pinnal margin, an ulcerated exophytic nodule on the right hock and a swelling in the right nostril. Cytological and histopathological findings were consistent with leishmaniosis. PCR confirmed the presence of Leishmania mexicana, a species endemic to Texas. An epidemiological investigation was conducted by trapping sandflies from the cat's environment. Sandflies collected were identified as Lutzomyia species, known vectors of Leishmania species. Given the lack of validated medical therapies for L mexicana in cats, treatments typically prescribed for canine leishmaniosis were administered. Allopurinol achieved clinical success but was discontinued due to suspected drug-related neutropenia. Topical imiquimod also improved lesional skin but was not sustainable due to application difficulty. Oral administration of artemisinin resulted in significant clinical improvement of cutaneous lesions without reported adverse events. Nearly 8 months after the initiation of artemisinin therapy, the cat remained systemically healthy with stable lesions. RELEVANCE AND NOVEL INFORMATION: This case report demonstrates endemic feline leishmaniosis in central Texas and provides the clinician with alternative therapeutic options for medical management.

Novel presentation of eosinophilic granuloma complex in a cat.

CASE SUMMARY: A 9-year-old neutered male domestic shorthair cat was presented for multiple deep lesions on all four limbs and a nodule on the right pinna. The limb lesions ranged from nodules with necrotic surfaces to full-thickness ulcerations with exposure of muscles and tendons. The cat lived indoors only in a single-pet household and had no prior history of trauma. The owner reported that the lesions appeared abruptly and that the cat was not apparently painful or pruritic. Histopathology of the limb lesions and pinnal nodule confirmed severe lesions of the eosinophilic granuloma complex. Resolution of lesions was achieved with a combination of antibiotics, prednisolone, topical therapies, diet change and ciclosporin. RELEVANCE AND NOVEL INFORMATION: This case report demonstrates a severe, aggressive presentation of eosinophilic granuloma complex. It will expose practitioners to atypical clinical signs of this commonly diagnosed disease.