Cathepsin W, T-cell receptor-associated transmembrane adapter 1, lymphotactin and killer cell lectin like receptor K1 are sensitive and specific RNA biomarkers of canine epitheliotropic lymphoma.

Cutaneous T-cell lymphoma (CTCL) is an uncommon type of lymphoma involving malignant skin-resident or skin-homing T cells. Canine epitheliotropic lymphoma (EL) is the most common form of CTCL in dogs, and it also spontaneously arises from T lymphocytes in the mucosa and skin. Clinically, it can be difficult to distinguish early-stage CTCLs apart from other forms of benign interface dermatitis (ID) in both dogs and people. Our objective was to identify novel biomarkers that can distinguish EL from other forms of ID, and perform comparative transcriptomics of human CTCL and canine EL. Here, we present a retrospective gene expression study that employed archival tissue from biorepositories. We analyzed a discovery cohort of 6 canines and a validation cohort of 8 canines with EL which occurred spontaneously in client-owned companion dogs. We performed comparative targeted transcriptomics studies using NanoString to assess 160 genes from lesional skin biopsies from the discovery cohort and 800 genes from the validation cohort to identify any significant differences that may reflect oncogenesis and immunopathogenesis. We further sought to determine if gene expression in EL and CTCL are conserved across humans and canines by comparing our data to previously published human datasets. Similar chemokine profiles were observed in dog EL and human CTCL, and analyses were performed to validate potential biomarkers and drivers of disease. In dogs, we found enrichment of T cell gene signatures, with upregulation of IFNG, TNF, PRF1, IL15, CD244, CXCL10, and CCL5 in EL in dogs compared to healthy controls. Importantly, CTSW, TRAT1 and KLRK1 distinguished EL from all other forms of interface dermatitis we studied, providing much-needed biomarkers for the veterinary field. XCL1/XCL2 were also highly specific of EL in our validation cohort. Future studies exploring the oncogenesis of spontaneous lymphomas in companion animals will expand our understanding of these disorders. Biomarkers may be useful for predicting disease prognosis and treatment responses. We plan to use our data to inform future development of targeted therapies, as well as for repurposing drugs for both veterinary and human medicine.

Using Gene Expression Analysis to Understand Complex Autoimmune Skin Disease Patients: A Series of Four Canine Cutaneous Lupus Erythematosus Cases.

Cutaneous Lupus Erythematosus (CLE) is an autoimmune skin disease that occurs in almost two-thirds of people with Systemic Lupus Erythematosus (SLE) and can exist as its own entity. Despite its negative impact on the quality of life of patients, lupus pathogenesis is not fully understood. In recent years, the role of gene expression analysis has become important in understanding cellular functions and disease causation within and across species. Interestingly, dogs also develop CLE, providing a spontaneous animal model of disease. Here, we present a targeted transcriptomic analysis of skin biopsies from a case series of four dogs with complex autoimmunity with suspected CLE. We identified 92 differentially expressed genes (DEGs), including type 1 interferon, B cell, and T cell-related genes, in the four cases compared to healthy skin margin controls. Additionally, we compared our results with existing CLE datasets from humans and mice and found that humans and canines share 49 DEGs, whereas humans and mice shared only 25 DEGs in our gene set. Immunohistochemistry of IFNG and CXCL10, two of the most highly upregulated inflammatory mediators, confirmed protein-level expression and revealed immune cells as the primary source of CXCL10 in dogs with SLE, whereas keratinocytes stained strongly for CXCL10 in dogs without SLE. We propose that gene expression analysis may aid the diagnosis of complex autoimmune skin diseases and that dogs may provide important insights into CLE and SLE pathogeneses, or more broadly, skin manifestations during systemic autoimmunity.

Gene Expression Analysis in Four Dogs With Canine Pemphigus Clinical Subtypes Reveals B Cell Signatures and Immune Activation Pathways Similar to Human Disease.

Pemphigus is a group of autoimmune-mediated mucocutaneous blistering diseases characterized by acantholysis. Pemphigus has also been recognized in dogs and shares similar clinical characteristics and variants with human pemphigus. While relationships between human and canine pemphigus have been reported, gene expression patterns across species have not been described in the literature. We sought to perform gene expression analysis of lesional skin tissue from four dogs with various forms of pemphigus to examine gene expression during spontaneous disease in dogs. We found increased T and B cell signatures in canine pemphigus lesions compared to controls, as well as significant upregulation of CCL3, CCL4, CXCL10, and CXCL8 (IL8), among other genes. Similar chemokine/cytokine expression patterns and immune infiltrates have been reported in humans, suggesting that these genes play a role in spontaneous disease. Direct comparison of our dataset to previously published human pemphigus datasets revealed five conserved differentially expressed genes: CD19, WIF1, CXCL10, CD86, and S100A12. Our data expands our understanding of pemphigus and facilitates identification of biomarkers for prediction of disease prognosis and treatment response, which may be useful for future veterinary and human clinical trials.

Shared inflammatory and skin-specific gene signatures reveal common drivers of discoid lupus erythematosus in canines, humans and mice.

Autoimmune skin diseases are complex and are thought to arise from a combination of genetics and environmental exposures, which trigger an ongoing immune response against self-antigens. Companion animals including cats and dogs are known to develop inflammatory skin conditions similar to humans and share the same environment, providing opportunities to study spontaneous disease that encompasses genetic and environmental factors with a One Health approach. A strength of comparative immunology approaches is that immune profiles may be assessed across different species to better identify shared or conserved pathways that might drive inflammation. Here, we performed a comparative study of skin from canine discoid lupus erythematosus (DLE) using NanoString nCounter technology. We compared these gene expression patterns to those of human DLE and a mouse model of cutaneous lupus. We found strong interferon signatures, with CXCL10, ISG15, and an S100 gene family member among the highest, most significant DEGs upregulated across species. Cell type analysis revealed marked T-cell and B-cell infiltration. Interestingly, canine DLE samples also recapitulated downregulated skin homeostatic genes observed in human DLE. We conclude that spontaneous DLE in dogs captures many features that are present in human disease and may serve as a more complete model for conducting further genomic and/or transcriptomic studies.

A Review of Immunotherapeutic Strategies in Canine Malignant Melanoma.

In dogs, melanomas are relatively common tumors and the most common form of oral malignancy. Biological behavior is highly variable, usually aggressive, and frequently metastatic, with reported survival times of three months for oral or mucosal melanomas in advanced disease stages. Classical clinical management remains challenging; thus, novel and more efficacious treatment strategies are needed. Evidence-based medicine supports the role of the immune system to treat neoplastic diseases. Besides, immunotherapy offers the possibility of a precise medicinal approach to treat cancer. In recent years, multiple immunotherapeutic strategies have been developed, and are now recognized as a pillar of treatment. In addition, dogs represent a good model for translational medicine purposes. This review will cover the most relevant immunotherapeutic strategies for the treatment of canine malignant melanoma, divided among five different categories, namely, monoclonal antibodies, nonspecific immunotherapy activated by bacteria, vaccines, gene therapy, and lymphokine-activated killer cell therapy.

Computed tomographic retrograde positive contrast cystography and computed tomographic excretory urography characterization of a urinary bladder diverticulum in a dog.

A one-year-old intact male German shepherd dog was referred with a 3-month history of dysuria and pollakiuria. Physical examination revealed a large firm mass in the caudal abdomen. Findings from survey radiography, negative contrast cystography, computed tomographic (CT) retrograde positive contrast cystography, and CT excretory urography were consistent with a large urinary bladder diverticulum. An exploratory laparotomy revealed a normal wall appearance in the ventral compartment (true bladder) and marked thinning of the wall in the dorsal compartment (diverticulum). Both ureters inserted into the ventral compartment. The dorsal compartment was excised and histopathology confirmed the diagnosis of urinary bladder diverticulum.

Selected serum oxidative stress biomarkers in dogs with non-food-induced and food-induced atopic dermatitis.

BACKGROUND: Oxidative stress (OS) has been shown to be involved in the pathogenesis of human and canine atopic dermatitis (AD) through several distinct mechanisms. Selected serum biomarkers of OS (sbOS) have been validated in normal dogs and studied in several canine diseases. To the best of the authors' knowledge, the sbOS evaluated in this study have not previously been described in canine AD. HYPOTHESIS/OBJECTIVES: The aims of the study were to evaluate a panel of sbOS in dogs with food-induced (FIAD) and non-food-induced (NFIAD) AD: cupric reducing antioxidant capacity (CUPRAC), ferrous oxidation-xylenol orange (FOX), ferric reducing ability of the plasma (FRAP), paraoxonase-1 (PON1), trolox equivalent antioxidant capacity (TEAC) and serum total thiol (THIOL). The aim was to compare these metabolites with those in healthy control dogs, and to correlate sbOS with validated pruritus and CADESI-04 severity scales in dogs with AD. ANIMALS: Forty six healthy, nine NFIAD and three FIAD client-owned dogs were included. METHODS: The study was designed as a cohort study. RESULTS: There were significant differences in atopic dogs when compared to healthy dogs for all of the sbOS analysed. CONCLUSIONS AND CLINICAL RELEVANCE: These findings suggest that OS could play a role in the pathogenesis of canine NFIAD and FIAD. In addition, the evaluation of sbOS could be useful for precision medicine to help to detect atopic dogs that might benefit from antioxidant-targeted therapies.

Subcutaneous extraskeletal osteosarcoma in a metatarsal footpad in a cat.

BACKGROUND: Extraskeletal osteosarcomas (ESOSAs) are rare neoplasms in humans and animals. In cats, ESOSA has been reported to arise from orbital, ocular, intestinal, mammary and subcutaneous locations. Subcutaneous ESOSA occurs most commonly at sites used for vaccination including interscapular, dorsal lumbar or thigh areas. Previous reports of feline cases have not documented the use of advanced diagnostic imaging to exclude a primary bone tumour. OBJECTIVE: To describe the clinicopathological and advanced imaging findings of a subcutaneous ESOSA occurring in a metatarsal footpad of a cat and to report the one year follow-up status. ANIMAL: A 9-year-old neutered male domestic short hair cat. METHODS: Physical, abdominal ultrasonographic and computed tomographic examinations, and excisional biopsy for histopathological and immunohistochemical evaluation. RESULTS: The cat presented with mild focal erythematous swelling of the left metatarsal pad. ESOSA was diagnosed through advanced diagnostic imaging and histopathological examinations. Histopathological findings were consistent with osteosarcoma. No primary bone disease was observed on computed tomography. The owners declined limb amputation. One year after diagnosis, the cat was alive without disease progression. CONCLUSIONS AND CLINICAL IMPORTANCE: Extraskeletal osteosarcoma should be considered in the differential diagnosis of soft tissue swelling in footpads in cats. Advanced diagnostic imaging is recommended to exclude primary bone tumours.

Accumulation and tissue distribution of heavy metals and essential elements in loggerhead turtles (Caretta caretta) from Spanish Mediterranean coastline of Murcia.

Sea turtles are of increasing interest as potential bioindicators of the heavy metal pollution in marine ecosystems. In the present work, concentrations of heavy metals and essential elements (As, Cd, Hg, Pb, Se, Zn) in different organs and tissues (liver, kidney, muscle, bone, blood, central nervous system and skin) of loggerhead sea turtles (Caretta caretta) were determined from stranded animals found along the Spanish Mediterranean coastlines of Murcia. Relatively high average levels of As (skin: 52.13 microg g(-1) dry weight; muscle: 40.95 microg g(-1) dry weight), and especially high individual levels of Zn in muscle tissue (1002.4 microg g(-1) dry weight) were detected. Furthermore, a significant degree of organotrophism of Cd was observed in kidney tissue. The concentrations detected, the distribution among the tissues and the differences observed between juvenile and adult specimens are generally compatible with chronic exposure to the elements studied, whilst levels produced by acute exposure were ruled out.

Pharmacokinetics of danofloxacin after single dose intravenous, intramuscular and subcutaneous administration to loggerhead turtles Caretta caretta.

The single-dose disposition kinetics of the antibiotic danofloxacin were determined in clinically normal loggerhead turtles (n = 6) after intravenous (IV), subcutaneous (SC) and intramuscular (IM) administration of 6 mg kg(-1) bodyweight. Danofloxacin concentrations were determined by high performance liquid chromatography with fluorescence detection. The concentration-time data were analyzed by non-compartmental kinetic methods. Steady-state volume of distribution, and total body clearance of danofloxacin after IV administration were estimated to be 1.02 +/- 0.17 1 kg(-1) and 0.11 +/- 0.01 1 h(-1) kg(-1), respectively. Following IM and SC administration, danofloxacin achieved maximum plasma concentrations of 10.25 +/- 4.59 and 10.35 +/- 4.45 mg l(-1) at 1.20 +/- 0.52 and 1.46 +/- 0.48 h, respectively. The absolute bioavailabilities after SC and IM routes were 98.72 +/- 11.73 and 104.81 +/- 14.97%, respectively. Danofloxacin shows a favourable pharmacokinetic profile in loggerhead turtles reflected by parameters such as a long half-life and a high bioavailability following a single dose of 6 mg kg(-1) by IM and SC routes; thus, it is likely that this treatment will be effective in loggerhead turtles with bacterial infections.