Outcome and complications associated with treatment of pemphigus foliaceus in dogs: 43 cases (1994-2000)

Re-evaluating the prevalence of anti-desmocollin-1 IgA autoantibodies in canine pemphigus foliaceus

Pemphigus foliaceus (PF) is an autoimmune skin disease of dogs characterized by intraepidermal pustules containing neutrophils and dissociated keratinocytes that develop in association with circulating and tissue-bound IgG autoantibodies. A subset of IgG autoantibodies in canine PF target desmocollin-1 (DSC1), a component of intercellular adhesion complexes within the epidermis. Passive transfer of IgG autoantibodies from canine PF sera to mice was previously shown to induce skin disease in the absence of infiltrating neutrophils. In attempts to identify a mechanism responsible for neutrophil recruitment, past studies evaluated the prevalence of IgA autoantibodies in canine PF sera where they were found in <20% of affected dogs. We re-evaluated the prevalence of anti-DSC1 IgA in canine PF due to concerns regarding the sensitivity of previously used methods. We hypothesized that anti-DSC1 IgA are present in most dogs with PF but have been under-detected due to competition with concurrent anti-DSC1 IgG for binding to their mutual antigenic target. Despite removing approximately 80% of IgG from patient sera using affinity chromatography, we did not detect an increase in anti-DSC1 IgA by performing indirect immunofluorescence on canine DSC1-transfected HEK293T cells. Taken together, our results do not support a role for pathogenic IgA in canine PF.

Efficacy of therapeutic plasma exchange in a case of severe, generalised canine pemphigus foliaceus

Successful treatment of pemphigus foliaceus (PF) often requires a multimodal therapeutic approach. The dog described herein underwent four therapeutic plasma exchange treatments for severe, refractory PF, resulting in a 50% reduction of lesional body surface area. This treatment option should be considered for the management of canine PF.

The use of oclacitinib compared to azathioprine in the management of canine pemphigus foliaceus: A retrospective analysis

BACKGROUND

Oclacitinib (Apoquel; Zoetis) has been reported to be beneficial for treating immune-mediated disorders.

HYPOTHESIS/OBJECTIVES

This retrospective study evaluates in which group of dogs [oclacitinib (OC) or azathioprine (AZ)] remission of pemphigus foliaceus (PF) was more effectively achieved with matched induction dosing of glucocorticoids; it further evaluates which group had a higher glucocorticoid-sparing effect.

ANIMALS

Review of 30 medical records of dogs diagnosed with PF presented to a private practice dermatological service.

MATERIALS AND METHODS

Retrospective analysis of dogs diagnosed with PF and treated with OC or AZ in combination with glucocorticoids.

RESULTS

There was no significant difference in the ability to induce remission between AZ and OC groups. In the AZ group, 13 of 15 dogs went into some type of remission (partial or complete), compared with 11 of 15 in the OC group. There was no significant difference between the two groups for the glucocorticoid-sparing effect. The AZ group had an average reduction of 77.9% from the induction glucocorticoid dose, and OC group had an average reduction of 64.4%. One of 15 patients in the AZ group and three of 15 patients in the OC group had a 100% reduction of the glucocorticoid dose.

CONCLUSIONS AND CLINICAL RELEVANCE

These results indicate that OC can be considered as a treatment option for canine PF.

Evidence-base for the beneficial effect of nutraceuticals in canine dermatological immune-mediated inflammatory diseases - A literature review

BACKGROUND

Immune-mediated inflammatory diseases (IMIDs) are associated with an abnormal immune response, resulting in a disturbed homeostasis and chronic inflammation. Most canine dermatological IMIDs (cDIMIDs), such as allergies, autoimmune and immune-mediated diseases, require long-term treatment with immunosuppressive drugs with potential adverse effects. In general, nutraceuticals are thought to be safe. As a result, there is a tendency for the more frequent use of nutraceuticals in veterinary medicine.

OBJECTIVES

The aim of this review was to present evidence-based proof for the use of various nutraceuticals in the treatment of cDIMIDs and, where possible, to provide conclusions to guide their use in veterinary dermatological practice.

METHODS

A comprehensive literature search on common cDIMIDs and nutraceuticals was performed. Only peer-reviewed articles published in English and related to the study topic were included. A total of 64 eligible publications were classified in five categories based on study design and substantively assessed on additional criteria such as standardisation of diets and number of included animals. For final appraisal, classification of major, minor or no evidence was used whereby efficacy was based on clinical outcome measurements.

CONCLUSIONS

Minor evidence for the beneficial use of several nutraceuticals, including essential fatty acids, niacinamide and probiotics, was found for treatment of specific cDIMIDs. These nutraceuticals may improve clinical signs or reduce the required dose of concurrent medication (e.g. drug-sparing effect) in some dogs. Some nutraceuticals also may be used for long-term maintenance therapy. Despite some promising findings, major evidence for the use of nutraceuticals in cDIMIDs is lacking, warranting further research.

Trunk-dominant and classic facial pemphigus foliaceus in dogs - comparison of anti-desmocollin-1 and anti-desmoglein-1 autoantibodies and clinical presentations

BACKGROUND

Canine trunk-dominant pemphigus foliaceus (PF) is mentioned rarely in the literature.

HYPOTHESIS/OBJECTIVES

The goal of this study was to provide clinical description of trunk-dominant PF and to demonstrate the prevalence of serum antikeratinocyte, anti-desmocollin-1 (DSC1) and anti-desmoglein-1 (DSG1) antibodies, and determine their diagnostic value in this particular PF phenotype.

MATERIALS AND METHODS

Clinically relevant information was collected from 31, 25 and 34 dogs with trunk-dominant and facial PF and superficial pyoderma (SP), respectively. Sera from these dogs were tested for antikeratinocyte, anti-DSC1 and anti-DSG1 antibodies using indirect immunofluorescence on canine tissues and DSC1- and DSG1-transfected cells. Sera from healthy dogs and dogs with clinically irrelevant diseases served as controls.

RESULTS

Footpad involvement and grouped/polycyclic lesion organisation were identified as features of both PF phenotypes, and not of SP. Antikeratinocyte immunoglobulin (Ig)G was not specific for canine PF. By contrast, antigen-specific IgG was detected only in PF sera; anti-DSC1 IgG in 100% and 58% of dogs with facial and trunk-dominant PF, respectively, and anti-DSG1 IgG in 7% of dogs with trunk-dominant PF only.

CONCLUSIONS

Trunk-dominant PF shares DSC1 as a major autoantigen with facial PF. The ability to detect anti-DSC1 IgG is lower in trunk-dominant PF, yet despite the lower sensitivity, the positive predictive value and accuracy of this particular anti-DSC1 IgG test are high. A negative test result, however, cannot exclude the diagnosis, and characteristic clinical features such as footpad involvement and/or grouped/polycyclic lesions must be considered when distinguishing trunk-dominant PF from its most relevant differential diagnosis: SP.

Clinical presentation, treatment and outcome in dogs with pemphigus foliaceus with and without vasculopathic lesions: an evaluation of 41 cases

BACKGROUND

Concurrent vasculopathic lesions in dogs with pemphigus foliaceus (PF) have been observed anecdotally yet not reported in the literature. Any association with prognosis is unclear.

HYPOTHESIS/OBJECTIVES

To compare clinical features and outcome of PF in dogs with and without vasculopathic lesions.

ANIMALS

Archived, formalin-fixed, paraffin-embedded biopsy samples of 41 dogs with PF.

METHODS AND MATERIALS

Archived, formalin-fixed, paraffin-embedded biopsy samples with a histological diagnosis of PF were selected and re-evaluated independently. Dogs were assigned to groups following histological evaluation: Group 1 (no vasculopathic lesions) and Group 2 (vasculopathic lesions present). Group 2 was subdivided into Group 2a (vasculopathic lesions without vasculitis - i.e. vasculopathy) and Group 2b (overt vasculitis). Medical records from identified cases were reviewed retrospectively for data on clinical presentation, treatment and outcome.

RESULTS

Time to remission was longer in Group 2b (93.8 days) compared to Group 1 (41.8 days) (P = 0.047). Dogs in groups 2a and 2b were more likely to have systemic signs of illness at presentation (P = 0.028 and P = 0.032, respectively) compared to Group 1. Dogs in Group 2b were more likely to have adverse effects associated with treatment than dogs in Group 1 (P = 0.004). There were no significant differences in lesion type, distribution, rates of remission, recurrence or corticosteroid dosage between groups.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with PF and concurrent vasculitis took longer to achieve remission and were more likely to have systemic signs of illness or adverse effects associated with treatment than dogs with PF without concurrent vasculopathic lesions.

Combination therapy with azathioprine, cyclosporine and ketoconazole in a dog with concurrent pemphigus foliaceus and hyperadrenocorticism - Case report

A 10-year-old, spayed female Shih Tzu dog presented with a history of progressive erythema and multiple crusts developing 85 days previously. The dog had been diagnosed with hyperadrenocorticism (HAC) 55 days prior to presentation and was treated with oral trilostane (2.86 mg/kg, once daily) that was discontinued due to a poor response. In addition to generalised alopecia, erythematous plaques and crusts were noted on the trunk, head and footpads. Lesional impression smears revealed numerous acantholytic cells and non-degenerated neutrophils. Histopathological findings demonstrated subcorneal pustules with acantholytic cells and intact neutrophils. On the basis of these findings, we diagnosed pemphigus foliaceus (PF) with concurrent HAC. We wished to avoid glucocorticoids and, therefore, prescribed oral, once-daily azathioprine (2 mg/kg), modified cyclosporine (7 mg/kg) and ketoconazole (5 mg/kg). By day 71 post-treatment, the erythematous crusts had almost disappeared and the alopecia had improved considerably. However, by the subsequent follow-up examination on day 99, the clinical signs had reappeared due to the tapering of cyclosporine. To the best of our knowledge, this is the first case report describing concurrent PF and HAC in a dog. Combination therapy with azathioprine, modified cyclosporine and ketoconazole was effective, and should be considered for dogs diagnosed with concurrent autoimmune diseases and HAC.

Efficacy of a Bruton's Tyrosine Kinase Inhibitor (PRN-473) in the treatment of canine pemphigus foliaceus

BACKGROUND

Bruton's tyrosine kinase (BTK) is important in B-cell signalling. Efficacy has been reported for BTK inhibitors (BTKi) in human autoimmune diseases. Canine pemphigus foliaceus (cPF) is the most common canine autoimmune skin disease.

OBJECTIVES

To determine the safety and efficacy of a BTKi in cPF treatment.

ANIMALS

Nine privately owned dogs.

METHODS AND MATERIALS

Nine dogs diagnosed with PF were administered BTKi PRN473. Initial dosages were ≈15 mg/kg once daily, increased to twice daily if inadequate response was seen. Treatment continued for a maximum of 20 weeks, attempting decrease to every other day. Dogs were monitored with complete blood counts, serum biochemistry panels, urinalyses and evaluated with a modified version of a validated human Pemphigus Disease Activity Index (cPDAI). Anti-desmocollin-1 (DSC-1) and desmoglein-1 (DSG-1) immunoglobulin G (IgG) titres were performed before and after the treatment period. Drug bound to target was measured in peripheral blood mononuclear cells.

RESULTS

All nine dogs showed reduction in lesions and cPDAI score during the first two weeks of treatment. At the end of the study, four responses were considered "good", two "fair", two "poor" and one dog withdrawn due to recurrence of a previously excised mast cell tumour. Four dogs continued to improve by Week 4; three sustained near complete remission by study's end. The anti-DSC-1 IgG titre decreased in three dogs, increased in two, was undetected in three and was not performed in the withdrawn dog. No dogs had detectable IgG to DSG1. Possible adverse effects occurred in three dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Bruton's tyrosine kinase inhibitor monotherapy may have beneficial effects in some cases of cPF.

Polysulfated Glycosaminoglycan as a Novel, Adjunctive Therapy for Pemphigus Foliaceus in Three Dogs

Three dogs who were presented with cutaneous lesions and had histopathologic findings consistent with pemphigus foliaceus were treated with injectable polysulfated glycosaminoglycan as an adjunctive to systemic immune-modulatory therapy. These patients were not adequately controlled with oral glucocorticoids in conjunction with cyclosporine, azathioprine, and/or mycophenolate. Polysulfated glycosaminoglycan contributed to induction of remission and reduced glucocorticoid doses in all dogs.

Feline pemphigus foliaceus: original case series and a comprehensive literature review

BACKGROUND

Since the first description of feline pemphigus foliaceus (PF) more than 30 years ago, numerous case reports have been published, while larger case series have remained rare. This large body of information, if extrapolated, could address clinical discrepancies and expand our knowledge about the treatment of feline PF. This manuscript reviews cases of feline PF published between 1950 and 2016 and adds additional 35 original cases to provide further insight into the clinical aspect and treatment outcome of this disease.

RESULTS

Feline PF, while being a primary acantholytic pustular dermatosis, presents most often with crusts and erosions that predominantly affect the face and feet. More than half of cats with active disease exhibits non-dermatological signs such as lethargy, fever and/or anorexia. The prognosis of feline PF is good as the majority of cats rapidly achieve disease control even with the most basic treatment such as glucocorticoid monotherapy. Most PF-affected cats, however, require long-term treatment and, like other autoimmune diseases, feline PF has a tendency to relapse spontaneously or with treatment changes.

CONCLUSIONS

Therefore, despite the overall good prognosis cats with PF can be given, owners should be informed and prepared for these circumstances, which may reduce the risk of euthanasia in the case of disease relapse, and improve treatment compliance.

CTLA4 overexpressing adipose tissue-derived mesenchymal stem cell therapy in a dog with steroid-refractory pemphigus foliaceus

Background

Canine pemphigus foliaceus is an autoimmune antibody-mediated skin disease characterized by acantholysis. The objective of this case report is to present the successful management of steroid refractory pemphigus foliaceus with cytotoxic T-lymphocyte antigen 4 (CTLA4)-overexpressing adipose tissue mesenchymal stem cells (ATMSCs).

Case presentation

A 10-year-old, 12.3-kg, castrated male Shih Tzu presented with severe pruritus and anorexia. The diagnosis of pemphigus foliaceus was made based on its history, physical examination, and histopathology results of a skin biopsy. Treatment with prednisolone and combination therapy of other immunosuppressive drugs had failed; therefore, immunosuppressive gene, CTLA4 overexpressing ATMSCs (CTLA4-ATMSCs) and/or naive ATMSCs administration was performed with the consent of the owner. ATMSCs were administered 21 times over a period of 20 months with intervals of 2 to 8 week. Prednisolone was gradually tapered concurrently and no relapse of the clinical signs was observed. After the termination of CTLA4-ATMSCs and/or naive ATMSCs treatment, the skin lesions had improved and could be managed with a low dose of prednisolone for 12 months.

Conclusion

CTLA4-ATMSCs or naive ATMSCs transplantation may be beneficial as adjunctive therapy to initiate and maintain the remission of skin lesions caused by pemphigus foliaceus in veterinary medicine.

Oral cyclosporine treatment in dogs: a review of the literature

Cyclosporine is an immunomodulatory drug used to treat an increasing spectrum of diseases in dogs. Cyclosporine is a calcineurin inhibitor, ultimately exerting its inhibitory effects on T-lymphocytes by decreasing production of cytokines, such as interleukin-2. Although, in the United States, oral cyclosporine is approved in dogs only for treatment of atopic dermatitis, there are many other indications for its use. Cyclosporine is available in 2 oral formulations: the original oil-based formulation and the more commonly used ultramicronized emulsion that facilitates oral absorption. Ultramicronized cyclosporine is available as an approved animal product, and human proprietary and generic preparations are also available. Bioavailability of the different formulations in dogs is likely to vary among the preparations. Cyclosporine is associated with a large number of drug interactions that can also influence blood cyclosporine concentrations. Therapeutic drug monitoring (TDM) can be used to assist in attaining consistent plasma cyclosporine concentrations despite the effects of varying bioavailability and drug interactions. TDM can facilitate therapeutic success by guiding dose adjustments on an individualized basis, and is recommended in cases that do not respond to initial oral dosing, or during treatment of severe, life-threatening diseases for which a trial-and-error approach to dose adjustment is too risky. Pharmacodynamic assays that evaluate individual patient immune responses to cyclosporine can be used to augment information provided by TDM.

Pênfigo foliáceo canino: estudo retrospectivo de 43 casos clínicos e terapia (2000-2005)

No período de agosto de 2000 a julho de 2005 foram atendidos 43 casos de Pênfigo Foliáceo (PF) canino no Serviço de Dermatologia do Hospital Veterinária, Universidade de São Paulo. Com este estudo retrospectivo visou-se atualizar dados referentes à caracterização sexual, definição racial e raça, idade, tipo e topografia lesional, quadro sintomático e resposta aos tratamentos isolados com prednisona e com a associação desta à azatioprina, além de demonstrar o aumento na ocorrência do PF relativamente à série histórica pretérita (1986-2000) do mesmo Serviço.

A review of autoimmune skin diseases in domestic animals: I - superficial pemphigus

In humans, the pemphigus denomination encompasses a group of autoimmune blistering skin diseases with intraepidermal separation resulting from cell-cell detachment by acantholysis. Entities are classified based on the level of blistering in the epidermis, and both superficial (pemphigus foliaceus, IgA pemphigus) and deep (pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus) variants are recognized. In domestic animals, subsets of pemphigus have been recognized since the mid-1970s, and the disease classification resembles that used for human patients. This article reviews up-to-date knowledge on the epidemiology, clinical signs, histopathology, immunopathology and treatment outcome of superficial pemphigus in domestic animals. Detailed information on canine, feline, equine and caprine pemphigus foliaceus, canine and feline pemphigus erythematosus and canine panepidermal pustular pemphigus is provided.

Pemphigus Foliaceus in 91 Dogs

A retrospective study of 91 dogs with pemphigus foliaceus was performed. Clinical signs of the disease included crusts (n=79), pustules (n=36), and alopecia (n=33). Lesions were most common on the trunk (n=53), inner pinnae (n=46), face (n=37), and foot pads (n=32). Cytological evaluation revealed acantholytic keratinocytes in 37 of 48 dogs. Results of combination treatment with prednisolone and azathioprine were comparable to results with prednisolone therapy alone. More than half of the dogs achieved remission with appropriate therapy, and another 25% significantly improved.