Plasma IL-8 concentrations are increased in dogs with spirocercosis

Cancerogenic parasites in veterinary medicine: a narrative literature review

Parasite infection is one of the many environmental factors that can significantly contribute to carcinogenesis and is already known to be associated with a variety of malignancies in both human and veterinary medicine. However, the actual number of cancerogenic parasites and their relationship to tumor development is far from being fully understood, especially in veterinary medicine. Thus, the aim of this review is to investigate parasite-related cancers in domestic and wild animals and their burden in veterinary oncology. Spontaneous neoplasia with ascertained or putative parasite etiology in domestic and wild animals will be reviewed, and the multifarious mechanisms of protozoan and metazoan cancer induction will be discussed.

Spirocerca lupi Proteomics and Its Role in Cancer Development: An Overview of Spirocercosis-Induced Sarcomas and Revision of Helminth-Induced Carcinomas

Spirocerca lupi is a parasitic nematode of canids that induces a myriad of clinical manifestations in its host and, in 25% of infections, leads to the formation of sarcomas. The description of the protein composition of the excretory and secretory products (Sl-ESP) of S. lupi has shed light on its possible interactions with the host environment, including migration within the host and mechanisms of immunomodulation. Despite this, the process by which S. lupi induces cancer in the dog remains poorly understood, and some hypotheses have arisen regarding these possible mechanisms. In this review, we discuss the role of specific ESP from the carcinogenic helminths Clonorchis sinensis, Opisthorchis viverrini and Schistosoma haematobium in inducing chronic inflammation and cancer in their host’s tissues. The parasitic worms Taenia solium, Echinococcus granulosus, Heterakis gallinarum, Trichuris muris and Strongyloides stercoralis, which have less-characterized mechanisms of cancer induction, are also analyzed. Based on the pathological findings in spirocercosis and the mechanisms by which other parasitic helminths induce cancer, we propose that the sustained inflammatory response in the dog´s tissues produced in response to the release of Sl-ESP homologous to those of other carcinogenic worms may lead to the malignant process in infected dogs.

Comparative study of the use of miltefosine, miltefosine plus allopurinol, and allopurinol in dogs with visceral leishmaniasis

Visceral leishmaniasis (VL) is an infectious disease caused by the protozoan parasite Leishmania (Leishmania) infantum, an intracytoplasmic parasite that affects humans and other species of domestic and wild mammals. In Brazil, the treatment of canine visceral leishmaniasis (CVL) with miltefosine has been implemented since 2016, and the reports on the clinical and immunological conditions of treated dogs are scarce. Thus, this study aimed to assess and monitor the clinical, laboratory, and immunological condition of dogs with CVL before (D₀) and after (D₂₉) using three pharmacotherapeutic protocols: miltefosine monotherapy (Milteforan™, Virbac) (G1), miltefosine plus allopurinol (G2), and allopurinol monotherapy (G3). Forty-five dogs with CVL were assigned to one of three treatment groups. The dogs were evaluated for clinical signs, was well as haematological, biochemical, serological, and cytokine levels. Significant reduction in clinical scores was observed in all protocols, with no differences between groups. We did not observe a clinical cure in any of the dogs in the groups. Haematological and biochemical parameters showed slow recovery, with better results observed in G2. Anti-Leishmania antibody titre remained increased in all groups. The quantification of serum cytokines demonstrated a mixed Th1/Th2 profile in CVL. The IL-2 levels decreased in all groups after treatment. Evaluation of IFN-y and IL-10 did not show changes in the groups analysed, and it did not contribute to short term therapeutic monitoring. All therapeutic protocols promoted, to varying degrees, an improvement in the general condition (clinical signs, haematological, and biochemical levels) of the animals. Through clinical-pathological exams, we found that the combination of miltefosine plus allopurinol promoted better effects in the short-term, representing the best choice for the treatment of CVL, even when compared to the only therapeutic protocol allowed in Brazil, miltefosine monotherapy. Through the quantification of cytokines, IL-2 proved to be a potential therapeutic marker for the monitoring and follow-up of dogs with CVL.

The use of primary murine fibroblasts to ascertain if Spirocerca lupi secretory/excretory protein products are mitogenic ex vivo

Background

Spirocerca lupi is a nematode that parasitizes vertebrates in particular canids, by forming nodules in the thoracic cavity specifically in the oesophagus. In 25% of Spirocerca infections of the domestic dog, nodules progress from inflammatory to pre-neoplastic to sarcomatous neoplasia. With the mechanism of neoplastic transformation being incompletely understood, this study investigates if S. lupi parasite proteinaceous secretory/excretory products (ESPs) play a role in the neoplastic transformation.

Methods

To facilitate collection of ESPs, we maintained naturally harvested adult parasites in the laboratory under artificial conditions. Media in which the parasites were grown was subsequently evaluated for the presence of proteinaceous compounds using a mass spectroscopy library as well as for their ability to be mitogenic in primary murine fibroblastic cells.

Results

Chromatrography of the ethyl acetate extracted incubation media showed the presence of 9 protein compounds, of which three were identified as non-specific proteins isolated from Nematostella vectensis, Caenorhabditis brenneri and Sus scrofa, with the rest being unknown. Acetone, methanol, hexane and ethylacetate extracted culture media were unable to induce a mitogenic change in primary murine fibroblasts in comparison to the controls.

Conclusion

While no mitogenic effect was evident, further studies are required to understand the role of worm excretory/secretory products on clastogenesis under chronic exposure. In addition, while not of primary importance for this study, the observed duration of parasite survival indicates that ex vivo studies on S. lupi are possible. For the latter we believe that the worm culture method can be further optimized if longer survival times are required.

Cytokine Concentrations Measured by Multiplex Assays in Canine Peripheral Blood Samples

Cytokines are known to play important roles in a wide range of pathologic conditions spanning all organ systems in every species studied. As our knowledge of the physiology of individual cytokines expands and our ability to measure multiple cytokines in smaller biological samples increases, we gain more insight into the significance and function of each cytokine and the importance of cytokine networks. Previous studies that reported measurements of cytokine concentrations from serum or plasma in dogs with infectious, autoimmune, metabolic, endocrine, and neoplastic diseases yield an appreciation for the complexity of cytokine control and potential applications for cytokine measurements in the diagnosis, prognosis, and therapy of a variety of disease conditions. In this review, we highlight the benefits of multiplex cytokine analysis, summarize clinical and experimental reports that have used this technology in dogs, and discuss the strengths and limitations of data analysis for the interpretation of results in these studies. We describe how differences in technical acuity, data reporting tactics, statistical analysis, study population selection criteria, and cross-sectional experimental design methods may affect interpretation of results from this technology. We also suggest methods for analysis in future studies, such as reporting median fluorescence intensity values, analyzing the proportion of patients above population medians, and performing longitudinal studies.

Excessive Pro-Inflammatory Serum Cytokine Concentrations in Virulent Canine Babesiosis

Babesia rossi infection causes a severe inflammatory response in the dog, which is the result of the balance between pro- and anti-inflammatory cytokine secretion. The aim of this study was to determine whether changes in cytokine concentrations were present in dogs with babesiosis and whether it was associated with disease outcome. Ninety-seven dogs naturally infected with B. rossi were studied and fifteen healthy dogs were included as controls. Diagnosis of babesiosis was confirmed by polymerase chain reaction and reverse line blot. Blood samples were collected from the jugular vein at admission, prior to any treatment. Cytokine concentrations were assessed using a canine-specific multiplex assay on an automated analyser. Serum concentrations of interleukin (IL)-2, IL-6, IL-8, IL-10, IL-18, granulocyte-macrophage colony stimulating factor (GM-CSF) and monocyte chemotactic protein-1 (MCP-1) were measured. Twelve of the Babesia-infected dogs died (12%) and 85 survived (88%). Babesia-infected dogs were also divided into those that presented within 48 hours from displaying clinical signs, and those that presented more than 48 hours after displaying clinical signs. Cytokine concentrations were compared between the different groups using the Mann-Whitney U test. IL-10 and MCP-1 concentrations were significantly elevated for the Babesia-infected dogs compared to the healthy controls. In contrast, the IL-8 concentration was significantly decreased in the Babesia-infected dogs compared to the controls. Concentrations of IL-6 and MCP-1 were significantly increased in the non-survivors compared to the survivors. Concentrations for IL-2, IL-6, IL-18 and GM-CSF were significantly higher in those cases that presented during the more acute stage of the disease. These findings suggest that a mixed cytokine response is present in dogs with babesiosis caused by B. rossi, and that an excessive pro-inflammatory response may result in a poor outcome.

Evaluation of hemostatic abnormalities in canine spirocercosis and its association with systemic inflammation

BACKGROUND

Canine spirocercosis is caused by the nematode Spirocerca lupi and is characterized by esophageal fibro-inflammatory nodules that may undergo neoplastic transformation. No sensitive and specific laboratory assays other than histopathology have been reported to differentiate non-neoplastic from neoplastic disease.

HYPOTHESIS/OBJECTIVES

Dogs with spirocercosis will have evidence of hypercoagulability based on thromboelastography (TEG)-derived maximal amplitude (MA); increased MA will be correlated with increased acute phase protein (APP) concentrations (C-reactive protein [CRP] and fibrinogen); increased MA and APPs will be exacerbated with neoplastic spirocercosis.

ANIMALS

Thirty-nine client-owned dogs with naturally occurring spirocercosis and 15 sex-matched healthy controls.

METHODS

A prospective comparative study evaluating TEG, activated partial thromboplastin time, prothrombin time, antithrombin (AT) activity, platelet count and D-dimer concentration, and APPs of dogs with non-neoplastic (n = 24) and neoplastic (n = 15) spirocercosis compared to control dogs.

RESULTS

Median MA was significantly increased in the non-neoplastic group (P < .01) and neoplastic group (P < .01) compared to the controls. Both APPs were significantly increased in the neoplastic group compared to the non-neoplastic and control groups. MA was strongly correlated with fibrinogen (r = 0.85, P < .001) and CRP (r = 0.73, P < .001). An MA >76 mm provided 96% specificity and 73% sensitivity for differentiation of disease state.

CONCLUSIONS AND CLINICAL IMPORTANCE

Canine spirocercosis is associated with increased TEG variables, MA and α, and decreased AT activity, which may indicate a hypercoagulable state seemingly more severe with neoplastic transformation. MA was correlated with APP in dogs with spirocercosis and can be used as an adjunctive test to support the suspicion of neoplastic transformation.

Spirocerca lupi-associated vertebral changes: a radiologic-pathologic study

Spirocerca lupi causes a caudal esophageal mass in dogs which may be accompanied by aortic changes and caudal thoracic spondylitis. Previous literature hypothesized that the spondylitis was caused by either aberrant larval migration or was secondary to the inflammation caused by the aortic migration. The current study aimed to evaluate these hypotheses. Ten dogs of various breeds and ages with radiographic evidence of spondylitis, which were necropsied, had the affected vertebrae removed and prepared for light and transmission electron microscopy examination. Transverse and sagittal sections of the ventral vertebrae were taken from 27 spondylitis and 8 spondylosis deformans lesions as well as from 8 normal vertebrae. Early spondylitis changes were characterized by periosteal woven new bone covered by hyperplastic periosteum with some involvement of the ventral longitudinal ligament. More mature lesions were characterized by nodules of denser trabecular bone and cartilage, also covered by hyperplastic periosteum and involved the ventral longitudinal ligament. It was difficult to distinguish the spondylitis and spondylosis deformans new bone. Inflammation was seen in five spondylitis cases (edema, lymphocytes, plasma cells, eosinophils and fibrin fibers). Spirocerca eggs were seen in one histologic section. This study shows that inflammation is mild and inconsistent in spirocercosis-induced spondylitis and that aberrant migration of the larvae or adults did not appear to be a predominant cause. Inflammatory mediators or osteoproliferative growth factors, which may be related to the primary esophageal lesion or to the worm itself, could be involved. This requires further investigation.