Efficacy of subcutaneous allergen immunotherapy in atopic dogs: A retrospective study of 664 cases.

BACKGROUND: Canine atopic dermatitis (cAD) is an allergic skin disease affecting approximately 10% of dogs. allergen-specific immunotherapy (ASIT) is currently the only treatment option able to induce tolerance to the causative allergens. OBJECTIVE: To retrospectively establish the efficacy of ASIT in atopic dogs. ANIMALS: Client-owned (n  = 664) dogs with cAD presented between 2008 and 2018 to two dermatology referral clinics. MATERIALS AND METHODS: Clinical records of atopic dogs were reviewed to obtain information including the results of the intradermal skin test and/or allergen-specific immunoglobulin (Ig)E serological results, the allergens included in the ASIT, concurrent symptomatic medications, and ASIT efficacy after at least 9 months. RESULTS: Excellent (ASIT alone controlled clinical signs), good (≥50% reduction of clinical signs) and poor (<50% improvement) responses were seen in 31.5%, 28.5% and 40.1% of the dogs, respectively. No significant differences in efficacy were associated with breed, sex, age at initiation of ASIT, type of allergens in ASIT, and between clinics. Dogs re-examined regularly responded significantly better to ASIT than dogs that did not (>50% improvement in 69.3% and 55.4% of the dogs, respectively). Dogs treated with ASIT and concomitant systemic glucocorticoids showed a significantly poorer response (success rate of >50% improvement of 38.5%). CONCLUSIONS AND CLINICAL IMPORTANCE: In 59.9% of atopic dogs, subcutaneous ASIT can improve clinical signs by ≥50%. The beneficial effect of ASIT is higher if dogs are re-examined regularly and if systemic long-term corticosteroids are avoided, at least during the first 9 months of ASIT.

Contexte - La dermatite atopique canine (DAC) est une maladie cutanée allergique qui touche environ 10 % des chiens. L'immunothérapie allergénique (ASIT) est actuellement la seule option thérapeutique capable d'induire une tolérance aux allergènes responsables. Objectif - Établir rétrospectivement l'efficacité de l'ASIT chez les chiens atopiques. Animaux - Chiens de clients (n = 664) atteints de DAC présentés entre 2008 et 2018 à deux cliniques de référé en dermatologie. Méthodes - Les dossiers cliniques des chiens atopiques ont été examinés pour obtenir des informations, notamment les résultats du test cutané intradermique et / ou les résultats sérologiques de l'immunoglobuline (Ig) E spécifique d'allergène, les allergènes inclus dans l'ASIT, les médicaments symptomatiques concomitants et l'efficacité de l'ASIT après au moins neuf mois. Résultats - Des réponses excellentes (signes cliniques contrôlés par l'ASIT seul), bonnes (réduction ≥ 50 % des signes cliniques) et médiocres (amélioration < 50 %) ont été observées chez 31,5 %, 28,5 % et 40,1 % des chiens, respectivement. Aucune différence significative d'efficacité n'a été associée à la race, au sexe, à l'âge au début de l'ASIT, au type d'allergènes dans l'ASIT et entre les cliniques. Les chiens réexaminés régulièrement ont répondu significativement mieux à l'ASIT que les chiens qui ne l'ont pas fait (amélioration > 50 % chez 69,3 % et 55,4 % des chiens, respectivement). Les chiens traités avec l'ASIT et des glucocorticoïdes systémiques concomitants ont montré une réponse significativement plus faible (taux de réussite > 50 % d'amélioration de 38,5 %). Conclusions et importance clinique - Chez 59,9 % des chiens atopiques, l'ASIT sous-cutanée peut améliorer les signes cliniques de ≥ 50 %. L'effet bénéfique de l'ASIT est plus élevé si les chiens sont réexaminés régulièrement et si les corticostéroïdes systémiques à long terme sont évités, au moins pendant les neuf premiers mois de l'ASIT.

Introducción- la dermatitis atópica canina (cAD) es una enfermedad alérgica de la piel que afecta aproximadamente al 10 % de los perros. La inmunoterapia con alérgenos (ASIT) es actualmente la única opción de tratamiento capaz de inducir tolerancia a los alérgenos causantes. Objetivo- establecer retrospectivamente la eficacia de ASIT en perros atópicos. Animales- perros de propietarios particulares (n=664) con cAD presentados entre 2008 y 2018 a dos clínicas de referencia de dermatología. Métodos- se revisaron las historias clínicas de los perros atópicos para obtener información, incluidos los resultados de la prueba cutánea intradérmica y/o los resultados serológicos de la inmunoglobulina (Ig)E específica para alérgenos, los alérgenos incluidos en el ASIT, los medicamentos sintomáticos concurrentes y la eficacia del ASIT después de al menos menos nueve meses. Resultados- se observaron respuestas excelentes (la ASIT sola controló los signos clínicos), buenas (≥50 % de reducción de los signos clínicos) y malas (<50 % de mejora) en el 31,5 %, 28,5 % y 40,1 % de los perros, respectivamente. No se asociaron diferencias significativas en la eficacia con la raza, el sexo, la edad al inicio de la ASIT, el tipo de alérgenos en la ASIT y entre las clínicas. Los perros reexaminados con regularidad respondieron significativamente mejor a la ASIT que los perros que no lo hicieron (>50 % de mejora en el 69,3 % y el 55,4 % de los perros, respectivamente). Los perros tratados con ASIT y glucocorticoides sistémicos concomitantes mostraron una respuesta significativamente peor (tasa de éxito de >50 % de mejora del 38,5 %). Conclusiones e importancia clínica - En el 59,9% de los perros atópicos, la ASIT subcutánea puede mejorar los signos clínicos en ≥50%. El efecto beneficioso de la ASIT es mayor si los perros se vuelven a examinar con regularidad y si se evitan los corticosteroides sistémicos a largo plazo, al menos durante los primeros nueve meses de la ASIT.

Contexto - A dermatite atópica canina (DAC) é uma doença alérgica que afeta aproximadamente 10% dos cães. A imunoterapia alérgeno-específica (ASIT) é atualmente a única opção terapêutica capaz de induzir tolerância aos alérgenos causadores. Objetivo - Estabelecer retrospectivamente a eficácia da ASIT em cães atópicos. Animais - Cães de proprietários (664) com DAC apresentados a duas clínicas de referência em dermatologia entre 2008 e 2018. Métodos - Os prontuários dos cães atópicos foram revisados para se obter informações incluindo os resultados dos testes intradérmicos e/ou sorológicos para anticorpos (IgE) alérgeno-específicos, os alérgenos incluídos na ASIT, medicações sintomáticas concomitantes, e a eficácia de ASIT após um mínimo de nove meses. Resultados - Resposta excelente (ASIT controlou os sinais clínicos sozinha), boa (redução ≥50% nos sinais clínicos) e pobre (<50% de melhora) foi observada em 31,5%, 28,5% e 40,1% dos cães, respectivamente. Não foram observadas diferenças significativas na eficácia em relação a raça, gênero, idade à iniciação da ASIT, tipo de alérgenos na ASIT e entre as clínicas. Os cães reavaliados periodicamente responderam significativamente melhor à ASIT que cães que não foram reavaliados com frequência (>50% de melhora em 69,3% e 55,4% dos cães, respectivamente). Cães tratados com ASIT e glicocorticoides sistêmicos concomitantemente demonstraram uma resposta significativamente mais pobre (a taxa de sucesso >50% ocorreu em 38,5%). Conclusões e importância clínica - Em 59,9% dos cães atópicos, ASIT subcutânea é capaz de melhorar os sinais clínicos em ≥50%. O efeito benéfico de ASIT foi maior se os cães fossem reavaliados regularmente e se corticoides sistêmicos a longo prazo fossem evitados, ao menos durante os primeiros meses de ASIT.

Discrepancies in the bilateral intradermal test and serum tests in atopic horses.

BACKGROUND: In equine atopic patients intradermal testing (IDT) and immunoglobulin (Ig)E serology are used frequently. There is little evidence regarding the reproducibility of the IDT and IgE serology in horses. OBJECTIVES: To compare the results of a simultaneously performed IDT on the left and right side of the neck in atopic horses, and to compare these results with allergen-specific IgE serology. ANIMALS: Ten equine patients from a university hospital population with chronic urticaria and/or pruritus. METHODS AND MATERIALS: The IDT was performed using 16 allergens and the results were evaluated after 30 min, 1, 4 and 24 h. Thirteen allergens also were analysed in duplicate with two monoclonal allergen-specific IgE enzyme-linked immunosorbent assays (ELISA). RESULTS: Good agreement (Kappa > 0.6) between left and right IDT was found only for Dermatophagoides farinae, Lepidoglyphus destructor, birch pollen mixture and perennial rye at 30 min, birch pollen mixture at 1 h, and Acarus siro and nettle and common mugwort mixture at 4 h. The bilateral comparison of the other allergens and even the same allergens at other time points showed little or no concordance between left and right IDT. The interlaboratory comparison between both ELISAs, and the comparison between the ELISAs and IDT, showed a good agreement for two of 13 allergens: D. farinae and Dermatophagoides pteronyssinus. CONCLUSIONS AND CLINICAL IMPORTANCE: Based on these preliminary data, IDT and IgE serological test results should be interpreted with great care and further studies are needed to indicate the clinical relevance of these findings.

Clindamycin resistance of skin derived Staphylococcus pseudintermedius is higher in dogs with a history of antimicrobial therapy.

BACKGROUND: In the Netherlands there is a lack of data regarding resistance of Staphylococcus pseudintermedius to the systemic antimicrobial drugs used for the treatment of superficial pyoderma. OBJECTIVES: To assess antimicrobial resistance, with emphasis on resistance to clindamycin and meticillin, in clinical isolates of S. pseudintermedius isolated from dogs with superficial pyoderma. Results were compared between dogs with and without a history of systemic antimicrobial therapy during the previous year. ANIMALS: A retrospective study of 237 referral cases presented to an academic teaching hospital between 2014 and 2019, with the clinical and microbiological diagnosis of superficial pyoderma. METHODS AND MATERIALS: All clinical isolates were identified primarily by MALDI-TOF mass spectrometry. Antimicrobial susceptibility was tested either by an agar diffusion method (2014-2016) or by broth microdilution. Antimicrobial history in the preceding year was obtained from medical records. RESULTS: Meticillin-resistant S. pseudintermedius (MRSP) was isolated from 8% of superficial pyoderma cases. Within the meticillin-susceptible S. pseudintermedius (MSSP) population, clindamycin resistance was significantly more common in isolates derived from dogs with histories of antimicrobial treatment (37.7%) compared to dogs with no histories of exposure (21.7%; P = 0.03). CONCLUSIONS: Given the high prevalence of clindamycin resistance in MSSP isolated from dogs with prior antimicrobial exposure, it is recommended that bacterial culture and susceptibility testing be pursued before prescribing systemic antimicrobials. Clindamycin should be regarded as the preferred treatment option if susceptibility is confirmed, due to its narrow spectrum and reduced selective pressure for MRSP.

Altered cutaneous expression of beta-defensins in dogs with atopic dermatitis.

Canine atopic dermatitis (AD) is a chronic allergic skin disorder with an immunopathogenesis comparable to that in humans with AD. The high frequency of recurrent infections with Staphylococcus pseudo intermedius and Malassezia pachydermatis may indicate a defective innate immune response in the skin of atopic dogs. Production of beta-defensins constitutes an important role in skin defense but information on canine beta-defensin localization and regulation is scarce. We conducted a gene-expression study of 16 canine beta-defensins (cBDs) in 11 tissues of healthy dogs, which revealed a variable expression of cBDs in different organ systems of the dog. In skin, three beta-defensins, cBD1, cBD103 and cBD107, were extensively expressed, while inconsistent expression of five other beta-defensins was detected. Using immunohistochemistry abundant expression of cBD103 peptide was detected in the epidermis, hair follicles and sebaceous glands, comparable to hBD3 expression in human skin. To examine the gene-expression of beta-defensins in atopic dogs, full thickness skin biopsy specimens (non-lesional and lesional) of 10 atopic dogs and 7 healthy dogs were examined with real-time PCR. A significant 12-fold increased expression of cBD1 was detected in lesional atopic skin compared to healthy skin, while non-lesional skin showed a 5-fold increase. Contrary to cBD1, expression of cBD103 was slightly (2-fold) downregulated in skin of atopic dogs. Gene-expression levels of S100A8, a marker for atopic dermatitis, were also highly upregulated in skin of atopic dogs, confirming the diagnostics of the skin biopsies. Taken together these results provide new evidence for a possible defect in the innate immune response of dogs with atopic dermatitis, and indicate the potential of the dog as a model for human AD.