Rosanna Marsella

University of Florida, Gainesville, Florida, United States

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Publications (95)145.27 Total impact

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    ABSTRACT: Background Tight junctions (TJ) are important for skin barrier function and could be relevant in modulating allergen penetration in atopic dermatitis (AD). Humans with AD have been described to have decreased expressions of some TJ proteins in the skin. Hypothesis/Objectives This study aimed to investigate TJ protein expression using an experimental AD model in dogs. Methods Skin biopsies from six atopic (nonlesional skin) and five normal beagle dogs were stained for TJ proteins [zonula occludens 1 (ZO-1), occludin, claudin-1] by immunohistochemistry. Staining intensity was evaluated both objectively using imaging software and subjectively. Six images/sections were randomized and blindly scored by six investigators for intensity, distribution, integrity and staining pattern. ResultsThe intensity of ZO-1 was significantly decreased in the atopic group objectively (P = 0.010) and subjectively (P = 0.002) relative to the normal group. Occludin was decreased significantly subjectively (P = 0.027) but not objectively. Claudin was not significantly different between groups by either quantification. Additionally, only ZO-1 demonstrated a significantly patchier staining pattern in the atopic group. There was no consistent staining pattern in this study. Conclusions and clinical importanceZO-1 and occludin, which have not been described to be associated with the development of AD in humans, could play a role in this atopic dog model. Further investigation on the expression and modulation of TJ proteins and their clinical relevance is needed. Resume ContexteLes jonctions serrees (Tight Junctions TJ) sont importantes pour la fonction barriere cutanee et pourraient egalement l'etre dans la regulation de la penetration antigenique de la dermatite atopique (AD). L'homme atopique a ete decrit comme ayant une expression augmentee de certaines proteines de TJ dans la peau. Hypotheses/ObjectifsCette etude porte sur l'expression des proteines TJ a l'aide d'un modele experimental d'AD chez le chien. MethodesDes biopsies cutanees de six chiens atopiques (peau non lesionnelle) et cinq chiens beagle sains ont ete colorees par immunohistochimie pour les proteines de TJ [zonula occludens 1 (ZO-1), occludine, claudine-1]. L'intensite de coloration a ete evaluee a la fois subjectivement et objectivement. Six images/sections ont ete reparties et notees en aveugle par six investigateurs pour l'intensite, la distribution, l'integrite et les patrons de coloration. ResultatsL'intensite de ZO-1 etait significativement diminuee dans le groupe atopique objectivement (P = 0.010) et subjectivement (P = 0.002) compare au groupe normal. L'occludine etait diminuee significativement subjectivement (P = 0.027) mais pas objectivement. La claudine ne presentait pas de difference significative entre les groupes quelque soit la quantification. En outre, seule ZO-1 montrait un patron de coloration en patch significatif dans le groupe atopique. Il n'y avait pas de patron de coloration significatif dans cette etude. Conclusions et importance cliniqueZO-1 et occludine, qui n'avaient pas ete decrit comme etant associe au developpement de l'AD humaine, pourraient jouer un role dans ce modele de chien atopique. D'autres etudes sont necessaires sur l'expression et la modulation des proteines de TJ et leur importance clinique. Resumen Introduccionlas uniones oclusivas intercelulares son importantes para la funcion de barrera de la piel y pueden ser relevantes en la modulacion de la proteccion de alergenos en casos de dermatitis atopica (AD). Los seres humanos con dermatitis atopica tienen una expresion disminuida de algunas proteinas en estas uniones. Hipotesis/Objetivoseste estudio esta enfocado a investigar la expresion algunas proteinas en los uniones oclusivas en un modelo experimental de dermatitis atopica en perros Metodosmuestras de piel de seis perros topicos (piel sin lesiones) y cinco perros normales de la piel se tineron para las proteinas de union de las uniones oclusivas (zonula occludens -1 (ZO-1), ocludina, claudina-1) mediante inmunohistoquimica. La intensidad de la tincion se evaluo objetivamente utilizando un programa de analisis de imagen y subjetivamente. Seis imagenes/secciones fueron distribuidas al azar y valoradas a ciegas por seis investigadores en referencia a distribucion, integridad, y patron de tincion. Resultadosla intensidad de ZO-1 estuvo significativamente disminuida en el grupo atopico tanto de forma objetiva (P= 0,010) como subjetiva (P= 0.002) en relacion al grupo normal. La ocludina estaba significativamente disminuida subjetivamente (P=0,027), pero no objetivamente. La claudina no fue significativamente diferente entre ambos grupos en ningun metodo cuantitativo. Ademas, solo ZO-1 demostro un patron de tincion mas granular en perros atopicos. No hubo un patron de tincion consistente en este estudio. Conclusion e importancia clinicaZO-1 y ocludina, que no han sido escritas como asociadas con el desarrollo de dermatitis atopica en humanos, podrian jugar un papel en este modelo de perros atopicos. Hace falta mayor investigacion de la expresion y modulacion de las proteinas de las zonas de union oclusivas y de su importancia clinica Zusammenfassung HintergrundTight Junctions (TJ) sind wichtig fur die Schutzfunktion der Haut und konnten bei der Regulierung der Penetration der Allergene bei atopischer Dermatitis (AD) wichtig sein. Bei Menschen mit AD wurde eine verminderte Exprimierung einiger TJ Proteine in der Haut beschrieben. Hypothese/ZieleDas Ziel dieser Studie war eine Untersuchung der Exprimierung der TJ Proteine mit einem experimentellen AD Modell bei Hunden. MethodenEs wurden Hautbiopsien von sechs atopischen (nicht veranderte Haut) und funf normalen Beagles mittels Immunhistochemie auf TJ Proteine gefarbt [Zonula occludens 1 (ZO-1), Occludin, Claudin-1]. Die Intensitat der Farbung wurde objektiv mittels bildgebender Software und subjektiv beurteilt. Sechs Bilder/Schnitte wurden zufallig und geblindet von sechs UntersucherInnen auf Intensitat, Verteilung, Integritat und Farbeverhalten bewertet. ErgebnisseDie Intensitat von ZO-1 war in der atopischen Gruppe im Vergleich zur normalen Gruppe objektiv (p=0,010) und subjektiv (p=0,002) vermindert. Occludin war subjektiv (p=0,027), aber nicht objektiv vermindert. Claudin war zwischen den Gruppen weder subjektiv noch objektiv signifikant unterschiedlich. Zusatzlich zeigte nur ZO-1 eine signifikant fleckigere Anfarbung als die atopische Gruppe. Es bestand keine konstante Anfarbung in dieser Studie. Schlussfolgerungen und klinische BedeutungZO-1 und Occludin, welche bisher nicht im Zusammenhang mit der Entstehung von AD beim Menschen beschrieben worden waren, konnten in diesem Modell des atopischen Hundes eine Rolle spielen. Es sind weitere Studien uber die Exprimierung und die Modulierung der TJ Proteine und ihre klinische Relevanz notig.
    No preview · Article · Dec 2015 · Veterinary Dermatology
  • Rosanna Marsella · Vassi Papastavros · Kim Ahrens · Domenico Santoro
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    ABSTRACT: Alterations in skin barrier function and filaggrin expression have been reported in atopic dermatitis (AD). Caspase-14, a protease important for filaggrin processing, is decreased in human AD. Atopic Beagle dogs with skin barrier alterations have been validated as model for AD. This study aimed to investigate caspase-14 in normal and atopic Beagle dogs. Skin biopsies from non-lesional and control skin were analyzed for caspase-14 by immunofluorescence. Six images/sections were blindly scored for intensity. Data were tested with unpaired Student's t test. A P value of <0.05 was considered significant. Caspase-14 was decreased in atopic compared to normal skin both quantitatively (P <0.001) and qualitatively (P = 0.006; agreement = 0.93; consistency = 0.94). In conclusion, caspase-14 is decreased in this model similarly to reports in humans, highlighting the relevance of filaggrin metabolic defects in AD.
    No preview · Article · Dec 2015 · The Veterinary Journal
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    ABSTRACT: Atopic dermatitis (AD) is an inflammatory skin disease characterized by infiltration of skin homing lymphocytes into the dermis. Most of these lymphocytes express the chemokine receptor CCR4 and the frequency of blood CCR4+ lymphocytes correlates with AD disease severity. Canine AD is a pruritic inflammatory condition that shows many features of the human disease including CCR4 overexpression. Therefore we tested a potent selective CCR4 antagonist in an allergen challenge model of canine AD, both clinically and histologically, to investigate whether this chemokine pathway plays a role in the inflammatory response. Using a four period randomized cross-over study design, 14 beagles were challenged with allergen and clinically monitored. Biopsies were taken before and after allergen challenge. A clear reduction of clinical scores was observed with oral prednisolone (p<0.0001), but not for the CCR4 inhibitor. A subset of the dogs (5/13) showed partial inhibition (30-49%) of the clinical signs with CCR4 inhibitor treatment and this was supported by the results of histopathology analysis of skin biopsies. This partial response is consistent with redundancy in chemokine pathways and highlights the need for therapies blocking multiple pathways. This study shows the utility of this canine model of AD for testing new therapeutic agents.
    Preview · Article · Nov 2015
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    Stephanie A. Regan · Rosanna Marsella · Ibrahim Ozmen
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    ABSTRACT: Psoriasis manifests as chronic dermatitis and arthritis (PsA) in people. Psoriasis with concurrent PsA is characterized by erythematous, silvery, scaly plaques, especially on the extremities, and concurrent arthritis with enthesitis, tenosynovitis, and dactylitis. To date, no such disease has spontaneously occurred in domestic animals. This case report aims to describe the clinical, radiographic, and histologic appearance of a psoriasis-like dermatitis and psoriatic-like arthritis in a dog. A 4-year-old female spayed pug mix presented for the evaluation of chronic history of hyperkeratotic footpads and deforming arthritis. After ruling out other differential diagnoses and based on the similarity of clinical, radiographic, and histologic findings to human psoriasis and PsA, a tentative diagnosis of psoriasis-like disease was made. Treatment was begun to control pain (tramadol, gabapentin, and carprofen) and psoriatic dermatitis (clobetasol propionate 0.05%, calcipotriene 0.005%, and urea 40% ointment twice daily). Dramatic positive response to treatment was achieved confirming the tentative diagnosis. This case may provide preliminary evidence for the existence of a psoriasis-like condition in dogs and may elucidate treatment options in otherwise refractory cases of chronic dermatitis and polyarthropathy in dogs.
    Full-text · Article · Sep 2015
  • Ha-Jung Kim · Kim Ahrens · Hee-Myung Park · Rosanna Marsella
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    ABSTRACT: Protease-activated receptor (PAR)-2 plays a crucial role in inflammation and the skin barrier. Protease-activated receptor-2 is activated by proteolytic enzymes of allergens and stimulates thymic stromal lymphopoietin (TSLP), promoting T-helper 2 cytokines. In humans with atopic dermatitis (AD), increased expression of PAR-2 and TSLP has been reported. To compare the pattern of staining of PAR-2 and TSLP between normal and atopic beagle dogs. The hypothesis tested was that increased expression is present in atopic dog skin compared with healthy control skin. Eight atopic and five normal dogs were challenged for 3 days with house dust mites. Skin biopsies were taken to measure the intensity, distribution, integrity and cell staining pattern on days 0, 3 and 10, both objectively and subjectively. Clinical signs were scored and compared between groups. Atopic dogs showed a significant increase in clinical scores on days 3 (peak of challenge) and 10 (resolution) and a significant condensed staining pattern for TSLP in the stratum basale at all times in comparison to normal dogs. They showed a significant patchy pattern for PAR-2 on days 0 and 3 and for TSLP at all times compared with normal dogs. The intensity itself was not significantly increased in atopic dogs compared with normal animals for both PAR-2 and TSLP. These preliminary findings do not confirm a difference in the amount of expression but rather in its pattern. Studies using PAR-2 or TSLP inhibitors could shed light on their clinical relevance. © 2015 ESVD and ACVD.
    No preview · Article · May 2015 · Veterinary Dermatology
  • Rosanna Marsella
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    ABSTRACT: Atopic dermatitis (AD) and food allergies are increasingly common in westernized countries. Peanut allergy affects more than 3 million Americans. Yet, treatments are still limited and testing is potentially very risky. Safe testing is needed before implementation in the clinics. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    No preview · Article · May 2015 · Experimental Dermatology
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    ABSTRACT: The development of atopic dermatitis (AD) and other cutaneous hypersensitivities involves the activation and differentiation of allergen-specific lymphocytes. Although hypersensitivity is often considered to be a 'T-helper 2-polarized' lymphocyte response, recent evidence suggests that clinical disease is associated with the development of multiple lymphocyte phenotypes. The purpose of this paper is to review recent advances in the understanding of the roles of lymphocytes, cytokines and noncytokine factors in the pathogenesis of canine AD. Citation databases, abstracts and proceedings from international meetings published between 2001 and 2013 were reviewed in this update. Where necessary, older articles were included for background information. The development of canine AD is associated with changes in both cutaneous and circulating lymphocyte populations. These lymphocyte responses are characterized by the production of a complex variety of cytokines, including not only T-helper 2 but also T-helper 1, T-helper 17 and regulatory T-cell responses. In addition, microarray gene expression analysis has enabled the identification of a number of noncytokine factors that appear to be associated with atopic inflammation. These include the calcium-binding protein S100A8, serum amyloid A and a number of protease inhibitors, as well as genes involved in epidermal barrier formation, innate immunity receptors, cell cycle proteins and apoptosis. The development of AD in dogs is characterized by the development of a delicate balance between a variety of T-cell phenotypes and inflammatory mediators, including cytokines, chemokines and noncytokine factors. © 2015 ESVD and ACVD.
    No preview · Article · Apr 2015 · Veterinary Dermatology

  • No preview · Article · Apr 2015 · Veterinary Dermatology
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    ABSTRACT: Multiple levels of evidence support the role of genetics and the environment in the pathogenesis of canine atopic dermatitis (AD). This review summarizes the current evidence in genetics and the effect of environmental factors on the development and perpetuation of canine AD. Citation databases, abstracts and proceedings from international meetings published between 2001 and 2013 were reviewed in this update. Where necessary, older articles were included for background information. Canine AD is a heritable disease, in which interaction with environmental factors influences disease risk and phenotype. A study of British guide dogs indicated that nearly 50% of the risk of developing AD was determined by an individual's genotype. Genomic studies performed so far in canine AD have uncovered numerous gene candidates likely to be involved in pathogenesis through their role in immunity, skin barrier formation, apoptosis and inflammation. In addition to genetics, there is evidence to suggest that exposure to certain environmental factors influences the prevalence and course of canine AD. For example, living in rural areas or feeding noncommercial diets was negatively associated with the development of AD in dogs, while exposure to high levels of smoke was associated with increased prevalence of allergic skin disease. It is becoming clear that canine AD is genotypically complex and influenced by a variety of environmental factors. Well-designed studies with sufficient statistical power will be critical to identify the complex genetic and environmental factors involved in disease development and progression. Recognition of such factors may help to identify new targets for therapy and enable better disease prevention and management. © 2015 ESVD and ACVD.
    No preview · Article · Feb 2015 · Veterinary Dermatology
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    ABSTRACT: Many studies focusing on clinical and histological signs of canine atopic dermatitis (AD) have been published since its early descriptions decades ago. Findings of these studies contributed to our current knowledge about the disease pathogenesis and allowed establishment of diagnostic criteria used by clinicians and researchers. This review serves as an update on the clinical and histological features of canine AD published by the American College of Veterinary Dermatology Task Force on Canine Atopic Dermatitis in 2001 and summarizes the recent discoveries in these fields. The overall findings of studies focusing on clinical features mirrored those published by the Task Force in 2001. The novelty was the larger number of animals included in these studies, which allowed establishment of a new set of diagnostic criteria that exceeded the sensitivity and specificity of the previous criteria. The same study uncovered some clinical differences between dogs with food-induced and nonfood-induced AD; however, the authors concluded that these two entities cannot be distinguished based on clinical signs only. Another study demonstrated some major breed-specific phenotypes. Several publications addressed the histological features of canine AD skin lesions in experimental models of AD, but none of those addressed naturally occurring lesions. Nevertheless, the histopathological description of the skin reactions was generally similar to that published by the Task Force in 2001. Considerable work has been done in recent years to provide a better definition of the clinical appearance and histopathology of canine AD. New sets of diagnostic criteria have been developed, and additional breed-associated differences in phenotypes have been demonstrated. © 2015 ESVD and ACVD.
    No preview · Article · Feb 2015 · Veterinary Dermatology
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    ABSTRACT: Epidermal tight junctions (TJ) have been well-described in human medicine and are involved in many skin diseases such as atopic dermatitis (AD). In dogs, there are no data regarding the implication of TJ in skin diseases including canine AD. The aim of this study was to compare the expression and the distribution of ZO-1, occludin and claudin-1 in the epidermis of healthy and atopic dogs. Skin biopsies from 6 high IgE-producing beagles sensitized to house dust mite (atopic group) were used. Skin specimens from nine healthy dogs without skin issues were sampled (healthy group). Immunoperoxydase staining was used to study the staining pattern of zonula occludens-1 (ZO-1), occludin and claudin-1 in the epidermis of healthy and atopic dogs. Positive controls were healthy human skin samples. Labeling patterns were assessed by 2 examiners blinded to the identities of the specimens. Comparisons between groups were performed using an exact Wilcoxon-Mann-Whitney test. The mean total expression score of claudin-1 was lower in atopic dogs as compared to healthy subjects. Occludin and ZO-1 expression remained unchanged within each group. These results suggest a defect in claudin-1 expression in the nonlesional epidermis of atopic dogs.
    No preview · Article · Feb 2015 · Canadian journal of veterinary research = Revue canadienne de recherche vétérinaire
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    Domenico Santoro · Kim Ahrens · Rosanna Marsella · Mariangela Segre
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    ABSTRACT: Increased secretion of antimicrobial peptides and cytokines is present in atopic skin. The purpose of this study was to compare the production of β-defensin (cBD)3-like, cathelicidin (cCath) and cytokines in atopic and healthy canine keratinocytes. Seven atopic house dust mites (HDM) sensitive and five healthy age-matched beagles were used. Keratinocytes were stimulated for 24 hours and the supernatant collected. A significantly higher production of cBD3-like was present at baseline in atopic compared with healthy keratinocytes, but cBD3-like did not increase after stimulation. IL-17 and lipopolysaccharide increased cBD3-like in healthy compared with atopic keratinocytes. cCath increased in both groups after stimulation. Atopic keratinocytes exposed to HDM produced more IL-8 and keratinocyte-derived chemokine-like than healthy keratinocytes. Exposure to HDM induced an increased IL-8 in atopic keratinocytes and a decreased IFN-γ in healthy keratinocytes. These results may suggest an over-sensitization of atopic keratinocytes and a possible impairment of the cutaneous defense against micro-organisms. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Full-text · Article · Feb 2015 · Experimental Dermatology
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    ABSTRACT: Canine atopic dermatitis (AD) is a common, genetically predisposed, inflammatory and pruritic skin disease. The pathogenesis of canine AD is incompletely understood. The aim of this review is to provide an in-depth update on the involvement of skin barrier and host-microbiome interaction in the pathogenesis of canine AD. Online citation databases and abstracts from international meetings were searched for publications related to skin barrier and host-microbiome interaction (e.g. bacteria, yeast, antimicrobial peptides). A total of 126 publications were identified. This review article focuses on epidermal barrier dysfunction and the interaction between cutaneous microbes (bacteria and yeasts) and the host (antimicrobial peptides). Epidemiological updates on the presence of pathogenic organisms and canine AD are also provided. Major advances have been made in the investigation of skin barrier dysfunction in canine AD, although many questions still remain. Skin barrier dysfunction and host-microbiome interactions are emerging as primary alterations in canine AD. Based on this review, it is clear that future studies focused on the development of drugs able to restore the skin barrier and increase the natural defences against pathogenic organisms are needed. © 2015 ESVD and ACVD.
    No preview · Article · Feb 2015 · Veterinary Dermatology
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    ABSTRACT: Canine atopic dermatitis (AD) is considered to be an immunoglobulin E (IgE)-mediated hypersensitivity response to environmental allergens. The role of other antibody isotypes and nonenvironmental allergens in disease pathogenesis remains unclear. The objective of this review is to provide an update on advances in the understanding of the relevance of specific antibody isotypes, autoallergens and nonenvironmental allergens in the pathogenesis of canine AD. Citation databases, abstracts and proceedings from international meetings published between 2001 and 2013 were reviewed. Where necessary, older articles were included for background information. Neither total nor allergen-specific IgE necessarily correlates with clinical disease in canine AD. Some dogs exhibit clinical signs that are indistinguishable from AD but have no demonstrable allergen-specific IgE (atopic-like dermatitis). Allergen-specific immunoglobulin G may be demonstrated in canine AD, but there is no evidence that this isotype plays a role in disease development. Although humans with AD may develop serum IgE against autoallergens, this finding has not been substantiated in the dog. In contrast, adverse food reactions are frequently co-associated with AD in the dog. Ingestion of food and environmental allergens may trigger exacerbations of AD. Determination of the role of IgE in the pathogenesis of canine AD still requires clarification. Clinical trials and research studies must distinguish atopic dogs with allergen-specific IgE or skin test reactivity from those without. There is no convincing evidence demonstrating a pathogenic role for either allergen-specific immunoglobulin G or autoallergens in canine AD, but food items may be triggers for disease flares in certain individuals. © 2015 ESVD and ACVD.
    No preview · Article · Feb 2015 · Veterinary Dermatology
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    ABSTRACT: The pathogenesis of canine atopic dermatitis (AD) involves dysfunction of the adaptive immune system. Recent evidence suggests that nonantigen-specific inflammatory elements may play a role in the development and perpetuation of canine AD. The objective of this review is to provide an update on recent advances in the understanding of the role of innate immune cells, keratinocytes, lipid metabolism and nutrition in the pathogenesis of AD in dogs. Citation databases, abstracts and proceedings from international meetings published between 2001 and 2013 are reviewed in this update. Where necessary, older articles are included for background information. Members of the innate immune system (including dendritic cells, Langerhans cells and mast cells) and keratinocytes interact with each other and with environmental antigens during both induction and effector phases of atopic inflammation. The responses of these cells and associated noncellular factors (such as complement and protease-activated receptors) to environmental stimuli influence the entire future course of the immune response to a given agent. Abnormalities in lipid metabolism may also influence the pathogenesis of canine AD via the production of inflammatory mediators and by alteration of epidermal barrier function and antigen presentation. However, a lack of fully controlled studies precludes definitive interpretation of these data. Evidence indicates that the cells and noncellular components of the innate immune system and the epidermis may play critical roles during both the sensitization and the effector phases of canine AD. Derangements in lipid metabolism may be involved in the pathogenesis of AD in dogs, but additional controlled studies are required in this area. © 2015 ESVD and ACVD.
    No preview · Article · Feb 2015 · Veterinary Dermatology
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    Ibrahim Ozmen · Rosanna Marsella
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    ABSTRACT: Atopic Dermatitis (AD) is a prevalent disease that affects both humans and animals. Dogs share similar environments with the owners and spontaneously develop a disease that is clinically and immunologically identical to AD in humans. In past decades AD has become more and more common in both dogs and humans, possibly due to the increased exposure to indoor allergens and decreased exposure to parasites and beneficial bacteria. The allergic component plays an important role in both species. Allergen specific immunotherapy (ASIT) has been used with great success in veterinary medicine for decades for the treatment of AD and traditionally has been accomplished with subcutaneous injections. In human medicine, ASIT has been traditionally used for respiratory manifestations of atopic disease and only recently considered for the therapy of AD. Interestingly, dogs primarily express cutaneous manifestations of atopic disease and only rarely progress from cutaneous into respiratory disease, a process referred in human medicine as “atopic march”. Recently, sublingual immunotherapy has been replacing subcutaneous immunotherapy both in human and veterinary medicine due to its ease and safety, leading to increased compliance. The purpose of this mini review is to focus on the use of sublingual immunotherapy for AD highlighting similarities and differences between humans and dogs.
    Full-text · Article · Oct 2014
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    Marsella R · Johnson C · Ahrens K
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    ABSTRACT: Atopic dermatitis (AD) is a common skin disease that affects humans and animals. Skin impairment has been described in human and canine AD. Equine AD is recognized in practice but little is known about its pathogenesis. As remarkable similarities exist across species in terms of cutaneous manifestations of AD, it was speculated that skin abnormalities may also exist in atopic horses. This case report describes the ultrastructure of the stratum corneum of two normal and two atopic horses. Biopsies were taken from sites predisposed to AD and examined using electron microscopy. Stratum corneum in normal samples was compacted with organized lipid lamellae while in atopic samples disorganized lipid lamellae, retained lamellar bodies and amorphous lipids were found. These changes are very similar to what reported in AD in other species. It is currently unknown whether these abnormalities in atopic horses are primary or secondary and their importance in allergen penetration.
    Full-text · Article · Oct 2014 · Research in Veterinary Science
  • D. Feld · R. Marsella · K. Ahrens
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    ABSTRACT: Skin barrier dysfunction has been reported to play an important role in both human and canine atopic dermatitis (AD). Inflammation can worsen skin barrier, thus it is reasonable to believe that therapy aimed at reducing inflammation should have a beneficial effect on skin barrier function. The present study aimed to investigate the effect of glucocorticoids and cyclosporine on skin barrier function in dogs with naturally occurring AD. Twenty-seven dogs with AD were randomly allocated to either prednisolone (0.5mg/ kg daily for the first week, then every other day for 3 weeks) or cyclosporine (5mg/kg once daily for 4 weeks). Skin barrier was assessed by measuring transepidermal water loss (TEWL) on pinnae, axillae, and groin on days 0 and 28. Clinical signs were scored on days 0 and 28. For clinical signs, analysis of variance showed a significant effect of time (P=0.03; end<beginning), but no effect of group or group x time interaction. For TEWL, no significant effects of time nor group were found. The only significance for TEWL was found for region (P<.0001, axilla>inguinal>pinna). The reason for lack of significant improvement of TEWL despite improvement of clinical signs is unclear at this time. Larger studies are needed to conclusively address the role played by inflammation on skin barrier dysfunction in dogs.
    No preview · Article · Jan 2014 · Journal of Applied Research in Veterinary Medicine, The
  • Rosanna Marsella
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    ABSTRACT: Allergies are common in horses. It is important to identify and correct as many factors as possible to control pruritus and make the patient comfortable. Culicoides hypersensitivity is a common component in allergic horses. The main treatment continues to be rigorous fly control and avoidance of insect bites. Environmental allergies are best addressed by early identification of the offending allergens and formulation of allergen-specific immunotherapy to decrease the need for rescue medications. Food allergy is best managed with food avoidance. Urticaria is one of the manifestations of allergic disease wherein detection of the triggering cause is essential for management.
    No preview · Article · Dec 2013 · The Veterinary clinics of North America. Equine practice
  • Rosanna Marsella
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    ABSTRACT: The literature on immune abnormalities in atopic dermatitis (AD) is quite extensive. A recent study in dogs with canine AD (CAD) reported that thymic stromal lymphopoietin (TSLP) expression in keratinocytes is increased after allergen stimulation with Dermatophagoides farinae. This study also found a significantly higher expression of TSLP in atopic skin compared to healthy control skin, suggesting that this cytokine may have a role also in CAD. In terms of dendritic cells, important similarities exist between atopic dogs and humans. Dendritic cells contribute to inflammatory processes through the activation of antigen-specific T cells. Dogs with CAD undergoing allergen-specific immunotherapy significantly increased the number of T regulatory cells (Tregs) over a course of 12 months, confirming a protective effect of these cells against allergies. Keratinocytes play an active role in the response to allergens and microbes, both by providing a physical and chemical barrier as well as interacting with immune system.
    No preview · Chapter · Oct 2013