An open study on the efficacy of a recombinant Der f 2 (Dermatophagoides farinae) immunotherapy in atopic dogs in Hungary and Switzerland.

BACKGROUND: Previously published studies evaluating a recombinant Der f 2-based immunotherapy have demonstrated efficacy in the treatment of dogs experimentally and naturally sensitized to house dust mites (HDM). Der f 2 sensitization is thought to play a minor role in European atopic dogs sensitized to HDM. OBJECTIVE: The study evaluated the short-term efficacy of a recombinant Der f 2 product in the treatment of naturally sensitized atopic dogs in Switzerland and Hungary. ANIMALS: Fifteen atopic dogs with positive test reactions to Dermatophagoides farinae (Df). MATERIAL AND METHODS: Recombinant Der f 2 allergens were injected subcutaneously at increasing doses once weekly for 6 weeks. Canine Atopic Dermatitis Extent and Severity Index (CADESI-04), pruritus Visual Analog Scale (pVAS) and medication scores were assessed at days 0 and 42. Efficacy was recorded as excellent, good, fair or poor, depending on the number of scores decreasing by more than 50%. RESULTS: Mean CADESI, pVAS and medication scores at inclusion were 35, 6 and 15 (SD = 30, 2, 7), respectively. At Day 42 the scores decreased to 8, 3 and 5, respectively (Wilcoxon matched pairs signed rank tests P = 0.0002, 0.002 and 0.001). Four dogs were classified as excellent responders with a reduction of >50% in all three scores. Nine dogs were classified as good (five) or fair (four) responders and scores deteriorated in two dogs. CONCLUSION: These data suggest that recombinant Der f2 allergens may be as effective and show benefit faster than traditional allergen immunotherapy in European dogs sensitized to Df.

A pilot study of total and allergen-specific IgE serum levels during anestrous, estrous and pregnancy in healthy female dogs.

BACKGROUND: Allergen-specific IgE serology is used for the determination of sensitization status in dogs with atopic dermatitis; the influence of the female reproductive cycle on the results of such methods has not been studied in dogs. OBJECTIVES: To compare the total and allergen-specific IgE of healthy bitches during anestrous, estrous and pregnancy. ANIMALS: Eight privately owned, healthy bitches. METHODS: Total and allergen-specific IgE levels were determined in eight bitches at three different time-points of their reproductive cycle: anestrous, estrous and pregnancy. RESULTS: Total IgE was significantly decreased (median: 74%) in female dogs during pregnancy when compared to anestrous. In 14 of 216 (6%), allergen-specific IgE test results were variably positive and negative at different stages of the reproductive cycle. This variation, however, was not related to changes in total serum IgE levels. CONCLUSIONS: Total IgE serum levels are reduced during pregnancy in female dogs. However, results of one allergen-specific IgE test did not appear to be markedly altered by the reproductive cycle in healthy bitches.

The effects of cryopreservation on the expression of canine regulatory T-cell markers.

BACKGROUND: Regulatory T (Treg) cells have been described as key regulators in various immunological processes and are of growing interest in veterinary allergy. Cryopreservation of immune cells is performed routinely in human basic science research and in clinical studies. As such, it allows batch testing of collected samples at a single time point, resulting in a significant reduction in sample variability. Data which describe the effects of cryopreservation on Treg cell frequency and functionality in the canine species are important to inform future research. HYPOTHESIS/OBJECTIVES: The purpose of this study was to establish a robust freeze/thaw procedure and flow cytometric staining protocol for canine Treg cells, and to compare the frequencies of different canine Treg cell phenotypes before and after cryopreservation. ANIMALS: Nine privately owned dogs. METHODS: Peripheral blood mononuclear cells were isolated and Treg cells stained and analysed by flow cytometry, before and after three months of cryopreservation. The recovery percentages and the corresponding correlations (fresh versus cryopreserved) for CD4+ CD25+ , CD4+ FOXP3+ and CD4+ CD25+ FOXP3+ cell populations were calculated. RESULTS: A high recovery rate of 97.2 (r = 0.94, P < 0.0001), 93.9 (r = 0.77, P < 0.01) and 101.7% (r = 0.99, P < 0.0001) for CD4+ CD25+ , CD4+ FOXP3+ and CD4+ CD25+ FOXP3+ cell populations, respectively, was observed. CONCLUSIONS: This study demonstrates an optimized protocol for freezing, thawing and quantifying canine Treg cells. These results indicate that cryopreservation does not substantially affect the expression of surface and intracellular markers of canine Treg cells; however, additional studies will be necessary to assess whether functionality of the cells is also maintained.

Prevalence and features of canine atopic dermatitis in Hungary.

Medical records of 600 dogs diagnosed with atopic dermatitis were reviewed and evaluated with reference to history, geographical distribution, breed predilection, clinical signs and positive reactions to allergens as determined by intradermal skin testing (IDT) manufactured by Artuvetrin Laboratories. In 66.6% of dogs, the age of onset of atopic dermatitis was between 4 months and 3 years. Dogs living in the garden suburb of Budapest were more sensitive to house dust mites, fleas and moulds, and dogs from the western part of Hungary were more sensitive to weeds than to other allergens (p < 0.01). Positive reactions were most common to Dermatophagoides farinae followed by human dander. The breed distribution found in the present study was consistent with that reported in the literature, except for the breeds Hungarian Vizsla, Pumi, French bulldog, Doberman Pinscher and Bobtail which were over-represented among atopic dogs compared to the breed distribution of the general dog population of a large city in Hungary. Breeds with verified adverse reaction to food were Cocker spaniels, French bulldogs, Bullmastiffs, Bull terriers, St. Bernards, Tervurens, West Highland White terriers and American Staffordshire terriers (p < 0.05). The clinical signs of atopic dermatitis and their occurrence are in accordance with the data described in the literature.

Recent developments in canine atopic dermatitis: a review.

Atopic dermatitis (AD) is a genetically predisposed inflammatory and pruritic allergic skin disease with characteristic clinical features. New results on the pathogenesis and therapeutic aspects are discussed in this review. IgE-mediated hypersensitivity may be involved in the largest subset of atopic patients, yet there is another subset for which such involvement cannot be documented. Alterations in epidermal barrier function, priming of cutaneous antigen-presenting cells with IgE, intrinsic keratinocyte defects, and development of autoimmunity are also factors that contribute to the primary disease. Polymorphisms in regions of the genome that are of key importance to the inflammatory response contribute to the patient's clinical picture. Secondary infections, especially with Staphylococcus and yeast organisms, strongly modify or augment the inflammatory response, which changes over time. After the treatment of secondary infections and skin inflammation the avoidance of causal allergens would prevent relapse. Another causative therapy is the variously effective allergen-specific immunotherapy. The newest treatments for canine AD (cyclosporin A and tacrolimus) are highly effective at suppressing the allergic response and comparable to treatment with glucocorticoids. Canine AD presents a substantial diagnostic and therapeutic challenge over a patient's lifetime, and no single treatment is universally effective.