Evaluation of Plasma C-Reactive Protein as a Biomarker in Dogs with Atopic -Dermatitis Receiving Allergen-Specific Immunotherapy: A Pilot Study.

INTRODUCTION: In this pilot study, we wished to determine if C-reactive protein (CRP) levels could be a useful severity or treatment biomarker for canine atopic dermatitis (AD). Nine atopic dogs received allergen immunotherapy for 1 year. Blood was collected before and at four re-evaluation visits. At each time point, the skin lesions were graded with the Canine Atopic Dermatitis Extent and Severity Index (CADESI) 4, and the plasma CRP levels were measured by Enzyme-linked Immunosorbent Assay (ELISA). We found a significant yet minimal correlation between the CRP levels and the CADESI4 scores. The CRP levels were not significantly different between dogs with AD of increasing severity. Finally, there was no correlation between the percentage change in CADESI4 and CRP values during immunotherapy. In conclusion, the lack of significant difference in CRP levels between dogs of increasing AD severity and lack of correlation between percentage changes in skin lesion and CRP values suggest that this protein would not be a clinically-useful biomarker in atopic dogs.

INTRODUCTION: Dans cette étude pilote, nous avons souhaité déterminer si les niveaux de protéine C-réactive (CRP) pourraient être un biomarqueur de gravité ou de traitement utile pour la dermatite atopique canine (DA). Neuf chiens atopiques ont reçu une immunothérapie allergénique spécifique pendant un an. Du sang a été prélevé avant et lors de quatre visites de réévaluation. À chacune de ces visites, les lésions cutanées ont été classées au moyen de l'indice d'étendue et de gravité de la dermatite atopique canine (CADESI) 4 et les taux plasmatiques de CRP ont été mesurés par dosage immuno-enzymatique (ELISA). Nous avons trouvé une corrélation significative mais minime entre les niveaux de CRP et les scores CADESI4. Les niveaux de CRP n'étaient pas significativement différents entre les chiens atteints de DA de gravité croissante. Enfin, il n'y avait pas de corrélation entre le pourcentage de changement des valeurs de ­CADESI4 et de CRP pendant l'immunothérapie. En conclusion, l'absence de différence significative des taux de CRP entre les chiens de gravité croissante de DA et le manque de corrélation entre les changements de ­pourcentage de lésion cutanée et les valeurs de CRP suggèrent que cette protéine ne serait pas un biomarqueur cliniquement utile chez les chiens atopiques.

Impact of the early-life skin microbiota on the development of canine atopic dermatitis in a high-risk breed birth cohort.

Canine atopic dermatitis (CAD) is a prevalent inflammatory skin disease of dogs worldwide. Certain breeds such as the West Highland White Terriers (WHWT) are predisposed to suffer from CAD. Microbial dysbiosis is known to play a significant role in the pathogenesis of the disease, which is similar to its human counterpart, atopic dermatitis (AD). To date, no large cohort-study has been conducted in a predisposed dog breed to study the impact of the early-life microbiota on the development of CAD, as well as the possible implication of factors such as hygiene and access to the outdoors. In this study skin samples of 143 WHWT, including 109 puppies up to three weeks old and 34 parent dogs, from 17 breeders, were subjected to 16S rRNA gene and ITS2 amplicon sequencing to disclose the bacterial and fungal oral and skin microbiota, respectively. The oral samples served as a control group to confirm differences between haired and mucosal surfaces. The cutaneous microbiota differed between sample sites and age of the dogs. The season of sampling, geographical origin as well as hygiene status of the household and the access to the outdoors shaped the skin microbiota of the puppies significantly. However, we found that the individual early-life microbiota did not predispose for the later development of CAD.

A Toxocara canis infection influences the immune response to house dust mite allergens in dogs.

BACKGROUND: The "hygiene hypothesis" suggests that a western way of life, including the extended use of anti-infective drugs, a high standard of hygiene and the resulting reduced exposure to microorganisms, could be one of the possible explanations for the increasing prevalence of allergic diseases in humans and animals. OBJECTIVES: we wished to evaluate if a nematode infection influenced IgE sensitization and allergic reactions to house dust mites in an experimental atopic dog model. METHODS: Twelve 10-week-old beagles were included: six of them were inoculated orally withToxocara canis (Tc) while six served as non-infected. Tc-specific IgE and IgG against Tc L3 E/S antigen (TcE/S antigen) were measured before and after Tc infection. All twelve dogs were sensitized epicutaneously to Dermatophagoides farinae (Df) house dust mites and then challenged twice epicutaneously with the mite. Total IgE and Df-specific IgE were measured before/after sensitization and after challenge. Local skin lesion scores were assessed before/after sensitization and after challenge while the duration of pruritus manifestations was measured by video after the second challenge. RESULTS: Toxocara canis -infected dogs exhibited higher levels of IgG and IgE levels against Tc, Df-specific IgE, total IgE but lower skin lesion scores and pruritus durations after challenge, compared to dogs not infested with this nematode. CONCLUSION & CLINICAL RELEVANCE: These observations suggest that a Tc infection increases the sensitization to Df in dogs. The possible protective effect against Df-induced clinical signs after allergen challenge should be confirmed in larger studies.

Age-Dependent Protective Effect of Selenium against UVA Irradiation in Primary Human Keratinocytes and the Associated DNA Repair Signature.

Few studies have focused on the protective role of selenium (Se) against skin aging and photoaging even though selenoproteins are essential for keratinocyte function and skin development. To the best of our knowledge, the impact of Se supplementation on skin cells from elderly and young donors has not been reported. Therefore, the main objective of our study was to evaluate the effects of Se supplementation on skin keratinocytes at baseline and after exposure to ultraviolet A (UVA) irradiation. Low doses of Se (30 nM) were very potently protective against UVA-induced cytotoxicity in young keratinocytes, whereas the protection efficiency of Se in old keratinocytes required higher concentrations (240 nM). Additionally, the DNA repair ability of the old keratinocytes drastically decreased compared with that of the young keratinocytes at baseline and after the UVA exposure. The Se supplementation significantly enhanced the DNA repair of 8-oxoguanine (8oxoG) only in the keratinocytes isolated from young donors. Therefore, aged keratinocytes have an increased vulnerability to oxidative DNA damage, and the Se needs in the elderly should be considered. Strengthening DNA repair activities with Se supplementation may represent a new strategy to combat aging and skin photoaging.

[Intralymphatic immunotherapy: An effective and safe alternative route for canine atopic dermatitis]. / Intralymphatische Immuntherapie: Eine sichere und effektive Methode zur Desensibilisierung der caninen atopischen Dermatitis.

INTRODUCTION: Allergen-specific immunotherapy (ASIT) is the only etiologic treatment of atopic dermatitis in dogs. In humans it has been shown that intralymphatic immunotherapy (ILIT) enhanced efficacy and patient compliance and reduced treatment time from 3 years to 8 weeks. As only safety data have been published yet, the aim of this study was to evaluate the clinical efficacy of ILIT in dogs. 20 atopic dogs underwent ILIT with alum-precipitated allergens administered every 4 weeks for 3 to 7 times in the popliteal lymph node. Pruritus (Hill score), CADESI (canine atopic dermatitis severety index), concurrent medications and adverse reactions were recorded initially and every 4 weeks for a total period of 24 weeks. The observed clinical response was good in 12/20 (60%) patients and improvement could be seen in some dogs already after 4 weeks. The median number of injections was 5.6. All dogs tolerated the procedure well and no adverse effects were recognized during or after ILIT. Therefore ILIT should be regarded as a safe alternative to subucaneous ASIT, enabling a faster clinical improvement with the same response rate.

INTRODUCTION: L'immunothérapie spécifique de l'allergène est le seul traitement étiologique de la dermite atopique du chien. On a pu montrer que, chez l'homme, l'immunothérapie intralymphatique (ITIL) augmente la fiabilité du traitement et permet de réduire sa durée de 3 ans à 8 semaines. Comme jusqu'à ce jour seules des données relatives à la tolérance avaient été publiées, la présente étude a pour but d'examiner l'efficacité clinique de l'ITIL chez les chiens. Vingt chiens atopiques ont été désensibilisés au moyen d'allergènes précipités à l'aluminium par ITIL dans les ganglions poplités toutes les 4 semaines. Le prurit (Hill score), le CADESI (canine atopic dermatitis severity index), les médicaments appliqués et les effets secondaires observés ont été enregistrés au début du traitement puis toutes les 4 semaines durant au total 24 semaines. 12/20 (60%) des patients ont bien répondu au traitement. L'amélioration clinique a pu être partiellement constatée après 4 semaines déjà. En moyenne, 5.6 injections ont été nécessaires. Tous les chiens ont bien toléré l'ITIL et il n'a pas été observé d'effet secondaire pendant ou après le traitement. L'immunothérapie intralymphatique semble donc une alternative sure à l'immunothérapie spécifique de l'antigène sous-cutanée et permet d'obtenir un effet plus rapide avec le même taux de réponse.

[Clinical symptomps, diagnosis and therapy of feline allergic dermatitis]. / Klinische Merkmale, Diagnose und Therapie des felinen Atopie Syndroms.

Allergies are often suspected in cats and they are mainly hypersensitivity reactions against insect bites, food- or environmental allergens. Cats, with non flea induced atopic dermatitis, normally present with one oft he following reaction patterns: miliary dermatitis, eosinophilic dermatitis, selfinduced alopecia or head and neck excoriations. None of these reaction patterns is nevertheless pathognomonic for allergic dermatitis, therefore the diagnosis is based on the one hand on the exclusion of similar diseases on the other hand on the successful response on a certain therapy. Recently a study on the clinical presentation of cats with non flea induced atopic dermatitis was published. In this study certain criteria for diagnosing atopy in cats were proposed. For therapy of allergic cats cyclosporin, glucocorticoids, antihistamines, hypoallergenic diets and allergen specific immunotherapy are used. This article should provide a recent overview on the clinical symptoms, diagnosis and therapy of feline allergic dermatitis.

EcPV2 DNA in equine papillomas and in situ and invasive squamous cell carcinomas supports papillomavirus etiology.

Equine penile papillomas, in situ carcinomas, and invasive carcinomas are hypothesized to belong to a continuum of papillomavirus-induced diseases. The former ones clinically present as small grey papules, while the latter 2 lesions are more hyperplasic or alternatively ulcerated. To test the hypothesis that these lesions are papillomavirus-induced, samples of 24 horses with characteristic clinical and histologic findings of penile papillomas or in situ or invasive squamous cell carcinomas were collected. As controls, 11 horses with various lesions--namely, Balanoposthitis (6 cases), melanoma (3 cases), follicular cyst (1 case), and amyloidosis (1 case)--were included. DNA was extracted and polymerase chain reaction applied to amplify papillomavirus DNA. The respective primers were designed to amplify DNA of the recently discovered equine papillomavirus EcPV2. All tested papilloma and squamous cell carcinoma samples were found to contain DNA of either of 2 previously published EcPV2 variants. Among the other samples 6 of 11 were found to contain EcPV2 DNA. To further support the findings and to determine where the papillomavirus DNA was located within the lesions, an in situ hybridization for the detection of EcPV2 DNA was established. The samples tested by this technique were found to clearly contain papillomavirus nucleic acid concentrated in the nucleus of the koilocytes. The findings of this study support previous data and the hypothesis that papillomaviruses induce the described penile lesions in horses.

Factors affecting allergen-specific IgE serum levels in cats.

Pruritic skin diseases are common in cats and demand rigorous diagnostic workup for finding an underlying etiology. Measurement of a serum allergen-specific IgE in a pruritic cat is often used to make or confirm the diagnosis of a skin hypersensitivity disease, although current evidence suggests that elevated allergen-specific IgE do not always correlate with a clinical disease and vice versa. The aim of the study was to to assess the possible influence of age, deworming status, lifestyle, flea treatment, and gender on allergen-specific IgE levels and to evaluate the reliability of IgE testing in predicting the final diagnosis of a pruritic cat. For this purpose sera of 179 cats with pruritus of different causes and 20 healthy cats were evaluated for allergen-specific IgE against environmental, food and flea allergens using the Fc-epsilon receptor based enzyme-linked immunosorbent assay (ELISA) test. The results of the study showed positive correlation between age, outdoor life style, absence of deworming, absence of flea control measures and levels of allergen-specific IgE. Gender and living area (urban versus rural) did not seem to affect the formation of allergen-specific IgE. According to these findings, evaluating allergen-specific IgE levels, is not a reliable test to diagnose hypersensitivity to food or environmental allergens in cats. On the contrary, this test can be successfully used for diagnosing feline flea bite hypersensitivity.

Role of the environment in the development of canine atopic dermatitis in Labrador and golden retrievers.

Canine and human atopic dermatitis are multifaceted diseases whose clinical development may be influenced by several factors, such as genetic background, environment, secondary infections, food and psychological effects. The role of the environment has been extensively examined in humans but remains unclear in dogs. The aim of this study was to examine environmental factors in two genetically close breeds, Labrador and golden retrievers. Using standard criteria, atopic dogs in Switzerland and Germany were selected and compared with healthy individuals. Information on environmental factors was collected using a 46-question survey encompassing date and place of birth, way of life at the breeder's and owner's home, food and treatments. Univariate and multivariate logistic regression were used to assess the association between potential risk factors and disease status. The following parameters were associated with an increased risk of disease development: living in a shed during puppyhood, adoption at the age of 8-12 weeks and washing the dog regularly. In contrast, the following factors were associated with a lower risk: living in a rural environment, living in a household with other animals and walking in a forest. These associations do not prove causality but support the primary hypothesis that certain environmental factors may influence the development of canine atopic dermatitis. Further studies are warranted to confirm these results and conclusions.

[Skin lesions and their distribution in the cat: lessons to be drawn]. / Les lésions cutanées et leur distribution chez le chat: leçons à tirer.

The specialty of dermatology has the invaluable advantage to provide direct visual access to the organ of interest, which therefore is characterised by a complex and complete semiology. This allows the clinician to efficiently limit the differential diagnosis. However, whereas in most species the focus lies in the assessment of the primary lesion resulting directly from the underlying pathologic process, in cats the assessment of the lesions' localisation and distribution is more important. The goal of this article is to illustrate the importance of considering the lesions' distribution and resulting reactive pattern at least as much as the nature of the lesion itself.

[Hyperprogesteronism due to bilateral adrenal carcinomas in a cat with diabetes mellitus]. / Hyperprogesteronismus infolge bilateraler Nebennierenrindenkarzinome bei einer Katze mit Diabetes mellitus.

An 8 year old male castrated Russian Blue cat with polyuria, polydipsia, polyphagia, abdominal enlargement, unkempt and easily epilated hair coat and abdominal alopecia is described. As a first step diabetes mellitus was diagnosed. Further work-up by ultrasonography revealed severe bilateral enlargement of the adrenal glands. Hypercortisolism was suspected and therefore ACTH stimulation test and dexamethasone suppression test were performed. In all samples cortisol concentrations were below the detection limit of the assay used. Various precursor hormones were measured and high progesterone concentrations were found. Histologically, the adrenal masses were characterised as bilateral adrenal carcinomas of the adrenal cortex. The case report demonstrates that adrenal gland tumors are also capable to secrete sex hormones instead of cortisol. Clinical signs of hyperprogesteronism are identical to those of hypercortisolism.

Sequence and classification of FdPV2, a papillomavirus isolated from feline Bowenoid in situ carcinomas.

Bowenoid in situ squamous cell carcinoma (BISC) is a rare feline skin disorder, which has been described as often associated with papillomavirus infection. It is clinically characterized by solitary or multiple hyperkeratotic plaques affecting older cats. Papillomavirus (PV) sequences amplified from feline viral plaques, and BISC lesions seldom correspond to FdPV1. The goal of the present study was to investigate three cases of BISC and to carry out initial genomic analysis of the associated viral DNA. Samples of skin biopsies taken from three BISC cats were histologically characterized. DNA was extracted and rolling-circle amplification was performed on the skin samples. Restriction enzyme analysis of the amplified DNA revealed the presence of a putative unknown PV. The whole genome was subsequently sequenced and cloned. Alignments with previously described feline PV sequences were carried out and phylogenetic trees were generated. The circular 7,899 base pair sequence of Felis domesticus PV type 2 (FdPV2) contains a typical noncoding region and characteristic open reading frames (ORF) for six putative viral proteins. Phylogenetic analysis based on the nucleotide alignment of L1 genes or the amino acid alignment of E1 proteins of FdPV2 and 52 other PV types indicates that FdPV2 might represent a new genus.

Clinical, histologic, and immunohistochemical analyses of feline squamous cell carcinoma in situ.

Actinic keratosis (AK) and Bowenoid in situ carcinoma (BISC) are two distinct forms of in situ squamous cell carcinoma in felines. They usually occur on different locations and present with specific clinical and histologic features. However, in some cases, these diseases cannot be distinguished either clinically or histopathologically. The aim of the present study was to determine the accuracy of diagnosis based on clinical or histologic criteria alone, and whether immunohistochemistry for papillomavirus or p53 can improve the accuracy of diagnosis. A series of in situ squamous cell carcinoma cases (n = 45) were selected according to their location and initial histologic classification and subsequently classified as AK (n = 22) or BISC (n = 23) according to the clinical criteria and were reevaluated histologically by 2 dermatopathologists. All BISC cases and most of the AK cases (n = 15) were confirmed histologically. In 7 cases clinically classified as AK, this diagnosis was not unanimously confirmed histologically because of the presence of overlapping features. P53 immunoreactivity was observed in 11/14 (79%) confirmed AK cases and in 4/22 (18%) BISC cases, while papillomavirus antigen was not detected in any confirmed AK case but was detected in 11/23 (48%) BISC cases. It was concluded that BISC can usually be reliably diagnosed histologically. The histologic diagnosis of lesions clinically suggestive of AK might sometimes be difficult. Results of immunohistochemistry for p53 and papillomavirus antigen were supportive for a role of sun exposure and papillomavirus in the pathogenesis of AK and BISC, respectively.

Detection of antibodies against epidermodysplasia verruciformis-associated canine papillomavirus 3 in sera of dogs from Europe and Africa by enzyme-linked immunosorbent assay.

The role of papillomaviruses (PVs) in the development of canine cancers is controversial. However, recently a novel canine PV (CPV3) was detected in a dog affected with a condition reminiscent of epidermodysplasia verruciformis (EV). The aim of the present study was to investigate the seroprevalence of CPV3 by using generic enzyme-linked immunosorbent assays (ELISAs) for the detection of antibodies against either canine oral PV (COPV) or CPV3. Therefore, the capsid proteins of both PV types were expressed as glutathione S-transferase fusion protein antigens and adsorbed to glutathione-casein-coated ELISA plates. After showing that PV type-specific antibodies could be detected in the sera from dogs with confirmed COPV or CPV3 infection, CPV3- and COPV-seropositive samples were detected in two sets of canine sera collected in Switzerland and South Africa, respectively. We found specific antibodies against COPV and CPV3 among the tested sera and also a large number that were positive for both antigens. The seroprevalences of PV antibodies of 21.9% (COPV) and 26.9% (CPV3) among the tested dogs from South Africa were higher than those among the dogs from Switzerland at 10.5% (COPV) and 1.3% (CPV3). Our data suggest a need for further CPV-related seroepidemiological surveys in different countries, especially in the context of clinical manifestations and possible breed predispositions. For this purpose, the newly developed ELISAs can be a useful tool.

A prospective study on canine atopic dermatitis and food-induced allergic dermatitis in Switzerland.

Canine atopic dermatitis sensu stricto and food-induced allergic dermatitis are common canine skin conditions, which are often considered clinically undistinguishable. Several attempts have been made to describe populations of atopic dogs and determine breed predisposition but the results were often biased by the use of hospital populations as control group. The present study aims to describe a population of Swiss atopic and food-allergic dogs and to compare it with a data set representing more than 85% of all Swiss dogs. The study, which was carried out during 1 year in several practices and teaching hospital in Switzerland, describes a group of 259 allergic dogs, determines breed predisposition for atopic dermatitis and food-induced allergic dermatitis, compares the clinical signs and features of both conditions, and outlines the clinical picture of five frequently affected breeds.

Detection of a novel papillomavirus in pigmented plaques of four pugs.

Pugs are predisposed to the development of deeply pigmented, slightly elevated hyperkeratotic noncancerous plaques. Polymerase chain reaction amplification of a papillomavirus (PV)-like DNA fragment from such lesions suggested that PV may be responsible for them, although the predicted virus has not yet been identified. The goal of the present study was to make use of pigmented plaques from four pugs to identify and sequence the predicted virus. Taking advantage of the circular nature of PV DNA, the entire viral genome was amplified by rolling circle amplification and restriction enzyme analysis disclosed the same pattern in all four cases. Sequencing of one of the amplificates revealed a novel canine PV, termed CPV4, related to the recently described CPV3 but clearly distinct from canine oral PV and CPV2. Thus, a novel canine PV and a method for its future diagnosis are described.

Two cases of FeLV-associated dermatoses.

Two cases of feline leukaemia virus (FeLV)-associated dermatosis are described. The first cat was affected by an ulcerative dermatitis identified as a giant-cell dermatosis. The second case was a cutaneous lymphoma. In both cases, FeLV antigens and FeLV genome were demonstrated in the affected skin immunologically and with polymerase chain reaction, respectively. The first case suggests that, like other retroviruses, at least some strains of FeLV can induce syncytium formation. As FeLV antigens and genome were demonstrated in a serologically negative cat, the second case suggests that focal skin FeLV replication may occur. FeLV-associated dermatoses are rare skin conditions that may be under-diagnosed.

Detection of novel papillomaviruses in canine mucosal, cutaneous and in situ squamous cell carcinomas.

Papillomavirus (PV) DNA is frequently uncovered in samples of human skin squamous cell carcinomas (SCC). However, the role of these viruses in the development of such cancers in canine species remains controversial. While approximately 100 human PVs are known, only one single canine oral PV (COPV) has been identified and studied extensively. Therefore, we applied a narrow-range polymerase chain reaction (PCR) suitable for the detection of classical canine and feline PVs, as well as a broad-range PCR, which has been used for the detection of various novel PVs in humans, in order to analyse 42 paraffin-embedded samples, representing three different forms of canine SCCs. Ten samples of skin tissues with various non-neoplastic conditions served as controls. While none of the negative controls reacted positively, PV DNA was discovered in 21% of the tested SCC samples. Interestingly, the classical COPV was amplified from only one sample, while the other positive cases were associated with a variety of thus far unknown PVs. This study suggests that a fraction of canine SCC is infected with PVs and that a genetic variety of canine PVs exists. Therefore, these results will facilitate the future study of the role of PVs in the development of canine skin cancers.

[Incidence, immunity and treatment of feline dermatophytosis]. / Vorkommen, Immunität und Behandlung der felinen Dermatophytose.

Feline dermatophytosis is a superficial skin infection characterized by the invasion of cornified tissues such as hair and nails. This infection is nearly always caused by Microsporum canis. Infected animals release infective spores in the environment which will then contaminate other animals or humans. Infected animals usually develop immunity so the infection will spontaneously disappear after a few weeks to months. Long haired and immunocom-promised cats do not have the same ability to acquire resistance and spontaneous recovery does usually not occur. The treatment of such an infection will require topical and systemic treatment of all contaminated and in-contact cats. The use of desinfectants such as bleach or enilconazole has been proven effective to destroy the spores in the environment. In addition, the efficacy of topical and systemic treatments with azole derivates or allylamines has also been demonstrated in several studies. On the contrary, dermatophyte vaccination has never been proven effective in well controlled studies. Regular follow-up and fungal cultures are mandatory to ensure succesfull treatment.