Cytokine Concentrations Measured by Multiplex Assays in Canine Peripheral Blood Samples

Vector-borne pathogens in dogs in Egypt: Molecular and immunological insights

Canine vector-borne diseases (CVBD) constitute a significant global health challenge, impacting dogs and posing zoonotic risks to humans. These diseases are transmitted through blood-feeding vectors such as ticks, fleas, and mosquitoes. This study, conducted in Cairo and Giza, Egypt, aimed to assess the prevalence, diversity, and clinical impact of CVBD in both domestic and stray dogs. Using microscopic and molecular diagnostic techniques, several pathogens were identified, including two primary zoonotic blood pathogens, Anaplasma platys and Leishmania spp., as well as other blood pathogens with varying degrees of zoonotic potential, such as Ehrlichia canis (E. canis), Anaplasma phagocytophilum, Anaplasma marginale, Babesia canis vogeli (B. canis vogeli), Hepatozoon canis, and Trypanosoma evansi. Stray dogs exhibited a higher prevalence of infection than domestic dogs, frequently presenting with co-infections. Clinically, infected dogs displayed clinical signs including weight loss, pale mucous membranes, lethargy, and anorexia, with more severe manifestations observed in cases with co-infections, particularly involving B. canis vogeli and E. canis. The immune response in these dogs was marked by elevated levels of inflammatory cytokines, such as tumor necrosis factor-α, interferon-γ, and interleukin-1β, which were significantly higher in symptomatic dogs, indicating a robust immune defense against the pathogens. Furthermore, markers of oxidative stress, including glutathione, malondialdehyde, and nitric oxide, were elevated in infected dogs, suggesting increased cellular damage due to prolonged infection and inflammation. The findings underline the key significance of stray dogs in the transmission and maintenance of CVBD and emphasize the necessity for comprehensive diagnostic, preventive, and control strategies to mitigate the prevalence of these diseases in dog populations and their potential zoonotic impact on human health.

Nucleated red blood cells for characterization of systemic inflammatory response syndrome in dogs

BACKGROUND

Nucleated red blood cells (nRBCs) are increased by disease processes and hematopoietic stress.

OBJECTIVES

To evaluate the utility of nRBCs as a marker of disease severity and prognosis in dogs with systemic inflammatory response syndrome (SIRS).

ANIMALS

Sixty-two client-owned dogs met the criteria of SIRS without anemia.

METHODS

nRBC-positive (nRBCs: ≥5/500, n = 32) and nRBC-negative (nRBCs: <5/500, n = 30) dogs were classified, and clinicopathological data, Acute Patient Physiologic and Laboratory Evaluation (APPLEfast) scores, cytokines, 2- and 4-weeks survival were compared.

RESULTS

The median WBC (17.63, interquartile range [IQR]: 11.72-20.24 × 109/L), neutrophils (12.28, IQR: 7.17-16.88 × 109/L), band neutrophils (1288.5, IQR: 252.5-2575 cells/μL), serum IL-6 (731.80, IQR: 299.79-5522.05 pg/mL), and plasma C-reactive protein (4.10, IQR: 1.00-8.58 mg/L) were significantly higher in nRBC-positive dogs than negative dogs (11.27, IQR: 7.63-15.13 × 109/L; 7.57, IQR: 4.96-11.71 × 109/L; 62.5, IQR: 0-350.25 cells/μL; 232.30, IQR: 99.33-447.01 pg/mL; 0.40, IQR: 0.10-3.00 mg/L, respectively; P < .05). The median reticulocyte count (87.95, IQR: 52.45-130.55 × 103/μL) and serum IL-3 (40.94, IQR: 29.85-53.52 ng/L) were also significantly greater in nRBC-positive dogs than nRBC-negative dogs (46.00, IQR: 26.43-68.15 × 103/μL; 25.24, IQR: 21.65-37.40 ng/L, respectively; P < .01). The presence of circulating nRBCs, but not the reticulocyte count, at admission was predictive of death in dogs with SIRS at 2 weeks (P = .01, AUC: 0.729) and 4 weeks (P = .002, AUC: 0.731). The overall survival time was shorter in nRBC-positive dogs (95% CI, 47.35-113.90) than nRBC-negative dogs (95% CI, 90.92-135.55; P = .03).

CONCLUSIONS AND CLINICAL IMPORTANCE

Measuring peripheral nRBCs in dogs with SIRS is rapid and clinically applicable, reflecting disease severity and associated prognosis.

KC-like chemokine as a biomarker of sepsis in dogs with pyometra

BACKGROUND

Sepsis, defined as a dysregulated inflammatory response to infection inducing organ dysfunction, is a common cause of mortality in both humans and animals. Early detection and treatment is essential for survival, but accurate diagnosis is challenging due to the lack of specific biomarkers for sepsis. This study explored the potential of the keratinocyte-derived chemokine (KC)-like protein in dogs as a biomarker of sepsis in dogs with bacterial uterine infection (pyometra). The aim was to compare KC-like concentrations in dogs with pyometra with or without sepsis and to assess associations between KC-like and clinical variables, including days of hospitalization as an outcome.

RESULTS

A mouse KC ELISA was validated and used to determine the concentrations of KC-like in serum from 34 dogs with pyometra and 18 healthy controls. Dogs with pyometra were classified as having sepsis based on two different criteria for systemic inflammatory response syndrome (SIRS), resulting in 74% and 30% sepsis-positive, respectively. The concentration of KC-like protein was higher in pyometra dogs with sepsis than in pyometra dogs without sepsis (p < 0.05) and in healthy controls (p < 0.0001) when using either of the two SIRS criteria. Moreover, KC-like was slightly increased in dogs with pyometra without sepsis compared with healthy controls when using the more stringent SIRS criteria (p < 0.05). Analyses of all dogs showed that KC-like concentrations correlated positively with hospitalization days, C-reactive protein (CRP) concentrations, white blood cells, and percentage of band neutrophils; however, KC-like correlated negatively with hemoglobin and did not correlate with circulating creatinine.

CONCLUSIONS

Our results suggest that circulating KC-like protein increases in dogs with sepsis in pyometra and that KC-like is associated with more severe clinical illness. These findings support a potential role of KC-like as a biomarker of sepsis; however, the true identity of KC-like in dogs has yet to be uncovered.

Bacterial microbiota and proinflammatory cytokines in the anal sacs of treated and untreated atopic dogs: Comparison with a healthy control group

The pathogenesis of anal sacculitis has not been extensively investigated, although atopic dogs seem to be predisposed to the disease. The aim of this study was therefore to characterize and compare the bacterial microbiota and pro-inflammatory cytokines in the anal sacs of dogs from three groups (healthy dogs, untreated atopic dogs and atopic dogs receiving antipruritic treatment or allergen-specific immunotherapy) in order to determine whether changes could be at the origin of anal sacculitis in atopic dogs. Bacterial populations of anal sac secretions from fifteen healthy dogs, fourteen untreated and six treated atopic dogs were characterized by sequencing the V4 region of the 16S rRNA gene using Illumina technology. Proinflammatory cytokines were analyzed with the Luminex multiplex test. Community membership and structure were significantly different between the anal sacs of healthy and untreated atopic dogs (P = 0.002 and P = 0.003, respectively) and between those of untreated and treated atopic dogs (P = 0.012 and P = 0.017, respectively). However, the community structure was similar in healthy and treated atopic dogs (P = 0.332). Among the proinflammatory cytokines assessed, there was no significant difference between groups, except for interleukin 8 which was higher in the anal sacs of untreated atopic dogs compared to treated atopic dogs (P = 0.02), and tumor necrosis factor-alpha which was lower in the anal sacs of healthy dogs compared to treated atopic dogs (P = 0.04). These results reveal a dysbiosis in the anal sacs of atopic dogs, which may partially explain the predisposition of atopic dogs to develop bacterial anal sacculitis. Treatments received by atopic dogs (oclacitinib, desloratadine and allergen-specific immunotherapy) shift the microbiota of the anal sacs towards that of healthy dogs. Further studies are required to identify significant cytokines contributing to anal sacculitis in atopic dogs.

Preliminary evaluation of the impact of periodontal treatment on markers of glycaemic control in dogs with diabetes mellitus: A prospective, clinical case series

BACKGROUND

Periodontal disease (PD) can adversely affect glycaemic control in humans. However, it is unknown if a similar association exists in dogs.

METHODS

Ten client-owned dogs with poorly regulated diabetes mellitus (DM) and PD were prospectively enrolled. A complete blood count, serum biochemistry, urinalysis and measurement of C-reactive protein, interleukin-6 (IL-6), tumour necrosis factor-α, haemoglobin A1c (HbA1c) and fructosamine concentrations were performed before periodontal treatment (PT) and monthly thereafter for 3 months. A periodontal disease severity score (PDSS) was determined during PT. The effects of time post-PT and PDSS on markers of inflammation and glycaemic control were determined by generalised estimating equation analysis.

RESULTS

HbA1c (mean; 95% confidence interval [CI]) decreased 3 months post-PT (32.1 mmol/mol; 21.1-43.1 mmol/mol vs. 44.3 mmol/mol; 36.4-52.0; p = 0.003). PDSS at enrolment was significantly (p = 0.031) positively associated with HbA1c concentration. Due to a significant (p < 0.001) interaction between PDSS and time post-PT in the analysis of fructosamine, dogs with low (1-3) PDSS and high (7-9) PDSS were analysed separately. Fructosamine (mean; 95% CI) significantly decreased 1 month post-PT (570 μmol/L; 457-684 μmol/L vs. 624 μmol/L; 499-748; p = 0.001) in the high PDSS group but not in the low PDSS group. Fructosamine concentration upon enrolment and PDSS were correlated (r = 0.73, p = 0.017). IL-6 concentration significantly decreased 3 months post-PT (9.9 pg/mL; 8.5-11.3 pg/mL vs. 11.2 pg/mL; 9.7-12.7; p = 0.002).

LIMITATIONS

Limitations of the study included the small number of dogs, the lack of a control group and the inability to assess PDSS during follow-ups.

CONCLUSIONS

These findings support a potential detrimental interaction between PD and DM. The apparent beneficial effect of PT on markers of glycaemic control was most conspicuous in dogs with more severe PD.

Use of extracorporeal therapy in a dog with heatstroke

OBJECTIVE

To describe the use of extracorporeal therapy (ECT) in the management of a dog with complications stemming from heatstroke.

CASE REVIEW

A 3-year-old intact male Rhodesian Ridgeback was presented for heat-related illness following strenuous exercise. Despite intensive supportive care, the dog developed progressive and refractory hyperkalemia, hypoglycemia, neurologic dysfunction, acute kidney injury (AKI), and pulmonary dysfunction. Four ECT sessions were performed in this dog, consisting of 4 intermittent hemodialysis (HD) sessions, the first 2 of which concurrently utilized hemoperfusion with a cytokine adsorption filter. Interleukin-6 (IL-6), IL-8, IL-10, and monocyte chemoattractant protein-1 were detected in samples collected during the first ECT session. Despite an initial decrease in their concentration, the concentrations of these cytokines ultimately rose over the course of the ECT session. Rapid and sustained glycemic and electrolyte control were achieved after the first ECT session, although AKI and muscle injury persisted. The dog survived to discharge and was nonazotemic 3 months following initial management.

NEW OR UNIQUE INFORMATION PROVIDED

Heatstroke is a common, potentially catastrophic, occurrence in dogs. To the authors' knowledge, this represents the first clinical use of ECT consisting of HD and cytokine adsorption in the management of severe heat-related illness in a dog. The use of ECT for the management of complications from severe heatstroke in dogs warrants further investigation.

Distinct trans-placental effects of maternal immune activation by TLR3 and TLR7 agonists: implications for schizophrenia risk

Exposure to infection in utero predisposes towards psychiatric diseases such as autism, depression and schizophrenia in later life. The mechanisms involved are typically studied by administering mimetics of double-stranded (ds) virus or bacterial infection to pregnant rats or mice. The effect of single-stranded (ss) virus mimetics has been largely ignored, despite evidence linking prenatal ss virus exposure with psychiatric disease. Understanding the effects of gestational ss virus exposure has become even more important with recent events. In this study, in pregnant mice, we compare directly the effects, on the maternal blood, placenta and the embryonic brain, of maternal administration of ds-virus mimetic poly I:C (to activate Toll-like receptor 3, TLR3) and ss-virus mimetic resiquimod (to activate TLR7/8). We find that, 4 h after the administration, both poly I:C and resiquimod elevated the levels of IL-6, TNFα, and chemokines including CCL2 and CCL5, in maternal plasma. Both agents also increased placental mRNA levels of IL-6 and IL-10, but only resiquimod increased placental TNFα mRNA. In foetal brain, poly I:C produced no detectable immune-response-related increases, whereas pronounced increases in cytokine (e.g. Il-6, Tnfα) and chemokine (e.g. Ccl2, Ccl5) expression were observed with maternal resiquimod administration. The data show substantial differences between the effect of maternal exposure to a TLR7/8 activator as compared to a TLR3 activator. There are significant implications for future modelling of diseases where maternal ss virus exposure contributes to environmental disease risk in offspring.

Altered plasma cytokines in dogs with atopic dermatitis

BACKGROUND

Canine (Canis lupus familiaris) atopic dermatitis (AD) shares similar clinical signs to human AD. The abnormal immune response of AD is orchestrated by T lymphocytes, and may include variable involvement of cytokines, regulatory T (Treg) cells, eosinophils, mast cells and other immune components. Helper T (Th)2 cytokines often predominate initially, followed by Th1 cytokines in more chronic phases.

HYPOTHESIS/OBJECTIVES

Pro-inflammatory and Treg cytokines have been shown to play a role in human AD, yet their importance is not clear in canine AD. Hence, this study aimed to measure the concentrations of cytokines/chemokines not traditionally associated with Th1/Th2 response.

ANIMALS

Canine AD patients (n = 27), compared to control dogs (n = 11).

METHODS AND MATERIALS

A total of 19 plasma cytokines were assayed using canine specific multiplex immuno-assays.

RESULTS

The plasma concentrations of CXC Motif Chemokine Ligand 8 (CXCL8), interleukin (IL)-7 and IL-15 cytokines were elevated in canine AD patients, compared to control dogs. In addition, stem-cell factor (SCF) concentrations were reduced in the plasma of canine AD patients compared to control dogs. Distinct cytokine profiles were found in dogs belonging to the Staffordshire breeds, a group with increased risk of AD. In particular, granulocyte-macrophage colony-stimulating factor (GM-CSF) had significantly elevated concentrations.

CONCLUSIONS AND CLINICAL RELEVANCE

Some of the plasma cytokine alterations in canine AD described here, particularly of IL-7, have not been reported previously. Monitoring these distinctive cytokine alterations could be useful for diagnosis and monitoring of canine AD in dogs.

Diving into Inflammation: A Pilot Study Exploring the Dynamics of the Immune-Microbiota Axis in Ileal Tissue Layers of Patients with Crohn's Disease

BACKGROUND AND AIMS

The pathogenesis of Crohn's disease [CD] is still unclear. Disorders in the mucosal immunoregulation and its crosstalk with the microbiota may represent an important component in tissue injury. We aimed to characterize the molecular immune response distribution within the ileal layers and to evaluate the correlated microbiota in pathological/healthy settings comparing first surgery/relapse clinical conditions.

METHODS

We enrolled 12 CD patients. A comprehensive analysis of an ileal mucosa, submucosa and serosa broad-spectrum cytokine panel was performed through a multiplex approach. In addition, ileal microbiota composition was assessed through next generation sequencing.

RESULTS

We observed a distinct profile [of IL1-α, IL-1β, IL-4, IL-8, ICAM-1, E-Selectin, P-Selectin, IP-10, IL 6 and IL 18] across the CD vs healthy ileal layers; and a different distribution of IFN- γ, P-Selectin, IL-27 and IL-21 in first surgery vs relapse patients. In addition, the phylum Tenericutes, the family Ruminococcaceae, and the genera Mesoplasma and Mycoplasma were significantly enriched in the pathological setting. Significant microbiota differences were observed between relapse and first surgery patients regarding the class Bacteroidia, and the genera Prevotella, Flavobacterium, Tepidimonas and Escherichia/Shigella. Finally, the abundance of the genus Mycoplasma was positively correlated with IL-18.

CONCLUSIONS

We describe a dissimilarity of cytokine distribution and microbiota composition within CD and adjacent healthy ileal tissue layers and between first operation and surgical relapse. Our results give potential insight into the dynamics of the gut microbiota-immune axis in CD patients, leading to detection of new biomarkers.

Automated blood sampling in canine telemetry model: Enhanced assessment of immune liabilities

INTRODUCTION

This manuscript presents a successful integration of multi-timepoint biomarker blood sampling (e.g., cytokines) in a conscious dog cardiovascular study using automated blood sampling via vascular access ports in telemetry instrumented dogs. In addition to determining plasma exposure of the test compound, the assessment of biomarkers of interest allows for more comprehensive preclinical evaluation on a traditional conscious dog cardiovascular (CV) telemetry study especially for immunology and immune-oncology molecules. This model system provides a rapid and efficient means to quickly gain understanding of potential effects on key cardiovascular parameters in large species that are commonly used for preclinical safety evaluations while collecting multiple blood samples for drug and cytokine analysis.

METHODS

Male beagle dogs were chronically implanted with telemetry devices (PhysioTel™ model D70-PCTP) and vascular access ports (SPMID-GRIDAC-5NC). BASi Culex-L automated blood sampling (ABS) (Bioanalytical Systems, Inc) system was used to collect blood samples at multiple time points for cytokine analysis. Four beagles received low-dose lipopolysaccharide solution (LPS) (0.1 and 0.5 μg/mL). The following cytokines were measured by Milliplex® map Canine Cytokine Magnetic Bead Panel: Interleukin (IL) 2, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, TNF-α, MCP-1, KC-like, GM-CSF, IFN gamma, and IP10.

RESULTS

Low dose LPS administration induced a pronounced dose-dependent, transient release of key inflammatory cytokines (IL-2, IL-6, IL-10, TNF-α, MCP-1, and KC-like). Cytokine responses were similar to other canine and human endotoxin models. LPS administration led to an increase in body temperature, heart rate, and mean arterial pressure, as well as a decrease in QTcV interval.

CONCLUSION

Successful incorporation of cytokine analysis in telemetry instrumented dogs with vascular access ports allows for translational PK/PD modeling of both efficacy and safety of compounds in the immunology as well as the immune-oncology therapeutic areas designed to modulate the immune system. Remote collection of blood samples simultaneously with CV endpoints is a significant enhancement for assessment of biomarkers that are sensitive to animal handling and excitement associated with room disturbances which are obligatory with manual blood collection. Furthermore, implementing this approach has also refined our animal welfare procedure by reducing the handling during a study and thereby reducing stress (positive refinement 3R impact).

Survey of cytokines on ocular surfaces of atopic dogs by multiplex analysis using two sampling methods - a pilot study

BACKGROUND

Conjunctivitis in atopic dogs has already been described yet is rarely observed, and likely underdiagnosed in practice.

OBJECTIVES

To assay various cytokines in tears and conjunctivae from atopic and normal dogs, and to compare canine atopic dermatitis-associated conjunctivitis with controls.

ANIMALS

Ten atopic and ten normal client-owned dogs.

METHODS AND MATERIALS

Ocular surfaces were sampled bilaterally in a prospective study, using two different methods. Tear samples were obtained with a sterile swab previously moistened with saline solution (method A). Conjunctival impressions were obtained with a conjunctival impression device (method B). For each sample, the concentrations of a panel of 13 cytokines were measured by multiplex analyses. CADESI-4, pruritus (PS) and conjunctival (CS) scores were determined.

RESULTS

Among the measured cytokines, only granulocyte-macrophage colony-stimulating factor (GM-CSF), keratinocyte-derived chemokine (KC)-like and interleukin (IL)-8 were above the limit of quantification in most samples. Absolute amounts of each cytokine were always higher in samples obtained with method A than with method B. GM-CSF amounts were lower in atopic dogs (method A, P=0.02; method B, P=0.0005). KC levels were higher in atopic dogs, yet the differences were not significant. IL-8 amounts were higher in atopic dogs (method A, P=0.0003; method B, P=0.006).

CONCLUSIONS AND CLINICAL RELEVANCE

Regardless of the method, these preliminary results suggest an overexpression of IL-8 in conjunctivae and tears of atopic dogs despite subtle conjunctival symptoms. As IL-8 is commonly found in many inflammatory conditions, further studies are needed to determine its specificity in atopic conjunctivitis.

Kinetics of Plasma Cytokines, Angiopoietin-2, and C-Reactive Protein in Dogs With Gastric Dilatation Volvulus

Background: The degree of systemic inflammation, reperfusion injury and endothelial activation are potentially important determinants of clinical outcomes in dogs with gastric dilatation volvulus (GDV).

Objective: To evaluate plasma concentrations and kinetics of inflammatory markers in dogs with GDV over a time frame of 48 h, and to compare to healthy dogs.

Design and Setting: Prospective, observational cohort study in client-owned dogs with GDV.

Materials and Methods: Fifteen dogs with GDV and 9 healthy control dogs were enrolled. Plasma concentrations of interleukin (IL)-6, IL-7, IL-8, IL-10, IL-15, IL-18, interferon gamma (IFN-γ), keratinocyte chemotactic-like, monocyte chemotactic protein (MCP)-1, Angiopoietin (Ang)-2, and C-reactive protein (CRP) were measured at admission (prior any therapeutic intervention, (T0), immediately after surgery (T1), 24 ± 4 h (T24), and 48 ± 4 h (T48) post-surgery. Cytokines were measured using multiplex magnetic bead assay. Plasma Ang-2 was measured with a commercial human ELISA test kit validated for dogs.

Results: Dogs with GDV had significantly higher plasma concentrations of IFN-γ and IL-10 compared to healthy control dogs at all time points. Concentrations of IL-6 were significantly higher at T1 and T24, concentrations of MCP-1 at T24, and concentrations of CRP at T24 and T48. A significant increase between T0 and T1 was found for IL-6, IL-10, and CRP, between T1 and T24 for IL-8, IFN-γ, MCP-1, and CRP, and between T24 and T48 for IL-15, Ang-2, and CRP. A significant decrease between T0 and T1 was found for IL-7, IL-8, IL-15, IL-18, and Ang-2; between T1 and T24 for IL-6 and KC-like; and between T24 and T48 for IL-6.

Conclusion: In GDV dogs, a mild pro-inflammatory reaction was present at admission, which peaked immediately after and up to 24 h post-surgery, mainly represented by IL-6, IFN-γ, MCP-1, and CRP, and which decreased at T48. In addition, the anti-inflammatory IL-10 was increased in GDV dogs at all time points.

Serum cytokine profiles in healthy nonhuman primates are blunted by sedation and demonstrate sexual dimorphism as detected by a validated multiplex immunoassay

Cytokine profiling is a valuable tool for monitoring immune responses associated with disease and treatment. This study assessed the impact of sex and sedation on serum cytokines in healthy nonhuman primates (NHPs). Twenty-three cytokines were measured from serum using a bead-based multiplex assay. Assay validation for precision, sensitivity, recovery, linearity, and stability was performed. Samples from male and female cynomolgus and rhesus macaques either cooperating or sedated were compared. All cytokines except TNFα demonstrated acceptable sensitivity and precision, with variable recovery and linearity. IFNγ, IL-2, IL-5, IL-6, IL-8, IL-12/23 (p40), IL-13, IL-15, MCP-1, TGFα, VEGF met acceptance criteria; G-CSF, IL-4, IL-10, MIP1α, sCD40L were marginal. Higher cytokine levels were observed in females and cytokine levels were blunted in sedated NHPs when compared to awake cooperating NHPs. Significant differences observed in cytokines related to sex, species, or imposed by handling highlight the importance of model design on translational relevance for clinical settings.

A preliminary evaluation of the circulating leptin/adiponectin ratio in dogs with pituitary-dependent hyperadrenocorticism and concurrent diabetes mellitus

Leptin and adiponectin are thought to modulate insulin sensitivity and pancreatic β-cell function, but there is limited information regarding the adipokine status of hyperglycemic dogs with hyperadrenocorticism. This study aimed to determine whether alterations in the leptin/adiponectin ratio, insulin sensitivity, and/or pancreatic β-cell function are associated with diabetes mellitus (DM) in dogs with pituitary-dependent hyperadrenocorticism (PDH). A total of 48 client-owned dogs were included in this prospective observational study: 20 dogs with PDH (10 normoglycemic and 10 with DM), 15 dogs with DM, and 13 healthy dogs. The serum concentrations of leptin, adiponectin, resistin, interleukin (IL)-1β, IL-6, IL-10, IL-18, and tumor necrosis factor (TNF)-α were measured, and homeostatic model assessment indices (HOMAs) were calculated and compared among the groups. Serum leptin was significantly higher in PDH dogs with and without DM than in healthy and DM dogs, and it was lower in DM dogs than in PDH dogs without DM. Serum adiponectin was significantly lower in PDH dogs with DM than in healthy and PDH dogs, and it was significantly lower in DM dogs than in healthy dogs. Serum IL-10 was significantly higher in PDH dogs with DM than in healthy and PDH dogs without DM. The leptin/adiponectin ratio was significantly higher in PDH dogs with DM than in normoglycemic PDH dogs. Serum IL-6 concentrations were significantly higher in DM dogs than in healthy dogs. Serum IL-1β concentration was significantly higher in DM dogs than in healthy dogs and PDH dogs with DM and without DM. Serum TNF-α and IL-18 concentrations were not different among groups. The HOMA_{β-cell function} was significantly lower in PDH dogs with DM than in normoglycemic PDH dogs, while HOMA_{insulin sensitivity} was significantly lower in PDH dogs with DM than in healthy dogs. These results suggest that adipokine dysregulation, a reduction in insulin sensitivity, and a further impairment in pancreatic β-cell function might predispose PDH dogs to DM. Further longitudinal study will be necessary to confirm this result.

Pain burden, sensory profile and inflammatory cytokines of dogs with naturally-occurring neuropathic pain treated with gabapentin alone or with meloxicam

Canine neuropathic pain (NeuP) has been poorly investigated. This study aimed to evaluate the pain burden, sensory profile and inflammatory cytokines in dogs with naturally-occurring NeuP. Twenty-nine client-owned dogs with NeuP were included in a prospective, partially masked, randomized crossover clinical trial, and treated with gabapentin/placebo/gabapentin-meloxicam or gabapentin-meloxicam/placebo/gabapentin (each treatment block of 7 days; total 21 days). Pain scores, mechanical (MNT) and electrical (ENT) nociceptive thresholds and descending noxious inhibitory controls (DNIC) were assessed at baseline, days 7, 14, and 21. DNIC was evaluated using ΔMNT (after-before conditioning stimulus). Positive or negative ΔMNT corresponded to inhibitory or facilitatory pain profiles, respectively. Pain scores were recorded using the Client Specific Outcome Measures (CSOM), Canine Brief Pain Inventory (CBPI), and short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Data from baseline were compared to those of sixteen healthy controls. ΔMNT, but not MNT and ENT, was significantly larger in controls (2.3 ± 0.9 N) than in NeuP (-0.2 ± 0.7 N). The percentage of dogs with facilitatory sensory profile was similar at baseline and after placebo (61.5–63%), and between controls and after gabapentin (33.3–34.6%). The CBPI scores were significantly different between gabapentin (CBPI _pain and CBPI _{overall impression}) and/or gabapentin-meloxicam (CBPI _pain and _interference) when compared with baseline, but not placebo. The CBPI scores were not significantly different between placebo and baseline. The concentration of cytokines was not different between groups or treatments. Dogs with NeuP have deficient inhibitory pain mechanisms. Pain burden was reduced after gabapentin and/or gabapentin-meloxicam when compared with baseline using CBPI and CMPS-SF scores. However, these scores were not superior than placebo, nor placebo was superior to baseline evaluations. A caregiver placebo effect may have biased the results.

Evaluation of cytokine concentrations in a trehalose-stabilised lyophilised canine platelet product: a preliminary study

Background

Platelet transfusion is indicated for haemorrhage due to severe thrombocytopenia and for trauma associated coagulopathy. Febrile non-haemolytic transfusion reactions are a common complication of platelet transfusions in people and may be due to accumulated inflammatory cytokines. The present study aimed to determine the cytokine profile of a novel canine lyophilised platelet product following reconstitution, to assess the lyophilised platelets’ activation response to physiological platelet agonists and to compare the cytokine profiles of basal and stimulated canine lyophilised platelets.

Methods

Cell counts and biochemical analyses were conducted following reconstitution. Cytokine concentrations were measured with a canine-specific multiplex immunocapture assay and with an electrochemiluminescent ELISA. Aliquots of reconstituted product from three separate vials were activated for 10 minutes under non-stirred conditions using adenosine diphosphate, thrombin or convulxin and their cytokine concentrations compared with unactivated samples. Flow cytometry and light-transmission aggregometry were used to evaluate the product’s ability to express a procoagulant surface, degranulate and aggregate. Fresh platelet-rich plasma was used as a positive control.

Results

The product had a mean±SD particle count of 1.23±0.2×10⁹/ml, contained platelets that expressed surface phosphatidylserine before agonist stimulation and was capable of aggregation in response to thrombin stimulation suggesting that the product may have haemostatic potential following in vivo administration. Cytokine concentrations measured by the immunocapture assay were generally low, while twofold to threefold increases relative to published intervals were noted for several cytokines using the ELISA. Concentrations of chemokine (C-X-C) motif ligand 8 and tumour necrosis factor-α were significantly increased as measured by the ELISA, but not by the immunocapture assay, while concentrations of KC-like were significantly increased as measured by the immunocapture assay. Stimulation with platelet agonists did not affect measured cytokine concentrations.

Conclusion

Further study of the effects of administration of this lyophilised platelet product is warranted.

A Pilot Study on the Safety of a Novel Antioxidant Nanoparticle Delivery System and Its Indirect Effects on Cytokine Levels in Four Dogs

Acute spinal cord injury consists of a primary, traumatic event followed by a cascade of secondary events resulting in ongoing cell damage and death. There is great interest in prevention of these secondary effects to reduce permanent long-term neurologic deficits. One such target includes reactive oxygen species released following injury, which can be enzymatically converted into less harmful molecules by superoxide dismutase and catalase. Canine intervertebral disc herniation has been suggested as a naturally occurring model for acute spinal cord injury and its secondary effects in people. The aims of this study were to test the safety of a novel antioxidant delivery system in four healthy dogs and to indirectly test effect of delivery via cytokine measurement. All dogs experienced adverse events to some degree, with two experiencing adverse events considered to be severe. The clinical signs, including combinations of bradycardia, hypotension, hypersalivation, pale gums, and involuntary urination, were consistent with complement activation-related pseudoallergy (CARPA). CARPA is a well-known phenomenon that has been reported to occur with nanoparticle-based drug delivery, among other documented causes. Two dogs also had mild to moderate changes in their blood cell count and chemistry, including elevated alanine transferase, and thrombocytopenia, which both returned to normal by day 7 post-administration. Cytokine levels trended downwards over the first 3 days, but many were elevated at measurement on day 7. Intradermal testing suggested catalase as a potential cause for reactions. No long-term clinical signs were observed, and necropsy results revealed no concerning pathology. Additional evaluation of this product, including further characterization of reactions to catalase containing components, dose-escalation, and desensitization should be performed before evaluation in clinically affected dogs.

Role of cytokines in the clinical manifestation of exophthalmia in newborn calves with tropical theileriosis

The present study aimed to evaluate the pathology of the exophthalmia and the host-immune response in naturally Theileria annulata-infected calves. The newborn calves detected positive for theileriosis were grouped into calves with theileriosis and absence of exophthalmia (n = 30), and calves with theileriosis and the presence of exophthalmia (n = 13). Sixteen healthy calves, free from any haemoprotozoal infection, were kept as healthy controls. A significantly (P ≤ .001) higher circulating levels of tumour necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were estimated in diseased calves with and without exophthalmia as compared to healthy controls. Contrarily, significantly (P ≤ .01) lower interferon-γ (IFN-γ) level was estimated in diseased calves. The diseased calves with exophthalmia revealed significantly higher levels of TNF-α (P ≤ .001) and IL-10 (P ≤ .006) as compared to the diseased calves without exophthalmia. The diseased calves were not found to have an elevated intraocular pressure; rather they had significantly (P ≤ .001) lower intraocular pressure compared to the healthy controls. An elevated systemic TNF-α level might be attributed to the exophthalmia in calves with tropical theileriosis. The elevated circulatory IL-10 and reduced IFN-γ levels could be one of the strategies of Theileria annulata to escape the host immunity.

Cytokine and Chemokine Profiling in Cats With Sepsis and Septic Shock

Background: Sepsis is a life-threatening condition associated with an exacerbated production of both pro- and anti-inflammatory cytokines that can promote a hyperactive response to infection or induce immunoparalysis. Data regarding the immune response to sepsis in cats are scarce. Establishing the profiles of cytokines and chemokines in feline sepsis to characterize the nature of the immune responses to sepsis might enable individualized treatments to be developed and targeted.

Objective: To evaluate the cytokine and chemokine network in cats with sepsis and septic shock, and to investigate the associations of these analytes with disease severity and outcome.

Methods: Blood samples prospectively collected at presentation of cats with sepsis and septic shock to two veterinary teaching hospitals were analyzed. Forty healthy cats were included as controls. A 19-plex feline cytokine/chemokine magnetic bead assay system was used to measure analytes in citrated plasma samples. Cytokine concentrations were compared between groups using the Kruskal-Wallis test with Dunn's post-hoc correction for multiple comparisons. Cytokine concentrations were compared between survivors and non-survivors with the Mann-Whitney U test. Odds ratios were calculated using logistic regression. A multivariable logistic regression model for prediction of septic shock was constructed.

Results: The study enrolled 35 septic cats. Many cytokines were undetectable in both sick and healthy control cats and were excluded from subsequent analyses. Comparisons of cytokine concentrations among healthy controls, cats with sepsis (n = 12) and cats with septic shock (n = 23) revealed that sick cats (sepsis or septic shock) had significantly higher plasma concentrations of IL-6, IL-8, KC-like, and RANTES compared to healthy controls. The combination of MCP-1, Flt-3L, and IL-12 was predictive of septic shock. None of the cytokines analyzed was predictive of outcome in this study population.

Conclusion: Plasma concentrations of IL-6, IL-8, KC-like, and RANTES are increased in cats with sepsis and may play important roles in pathogenesis. Multivariable modeling suggested that analysis of cytokines might aid differentiation of septic shock from sepsis. None of the cytokines analyzed was predictive of outcome. Measurement of these cytokines might enable future studies to better diagnose and characterize feline sepsis and septic shock.

Quantification of immuno-regulatory cytokine and toll-like receptors gene expression in dogs with generalized demodicosis

The proliferation of Demodex mites is mainly controlled by host immunity; however, the precised mechanism of host-mite interplay and host immune response in the cutaneous microenvironment of dogs with generalized demodicosis (GD) are not yet established. In the present study, we envisaged the alterations in the expression of toll-like receptors (TLRs) and immuno-regulatory cytokine gene in the skin lesions and peripheral blood mononuclear cells (PBMCs) of dogs with GD. The expression of TLR2, TLR6, IFN-γ, TGF-β and IL-10 genes in the skin lesions and PBMCs of 15 dogs with GD was quantified by qRT-PCR. Compared to healthy dogs, significantly elevated expression of TLR2 (P = 0.048), TGF-β (P = 0.04) and IL-10 (P = 0.012) were found in the PBMCs of dogs with GD. Conversely, there was significantly reduced expression of TLR6 gene (P = 0.021) in the PBMCs of these dogs. The infested dogs also revealed significantly elevated expression of TLR2 gene (P = 0.034) in the skin lesions, while, the expression of the TLR6 gene was found to be significantly (P = 0.004) reduced. Interestingly, significant alterations in TGF-β (P = 0.105) and IL-10 (P = 0.162) genes expression were not observed in the skin lesions of diseased dogs. Our findings suggest that Demodex mites contribute to a different systemic and cutaneous immune response in dogs for their proliferation, and consequently the development of GD. Therefore, Demodex mites might be inducing the immunosuppression through activating the systemic over-expression of immunosuppressive cytokines; however, in the cutaneous lesions, the expression of immunosuppressive cytokines remained unaltered. Both systemic and local over-expression of TLR2 and reduced expression of TLR6 genes might be responsible for the inflammatory signs of canine demodicosis and helping to the mite to escape the host immunity.

Neutrophil Myeloperoxidase Index in Dogs With Babesiosis Caused by Babesia rossi

Babesiosis caused by the virulent tick-borne hemoprotozoan, Babesia rossi, results in a marked systemic inflammatory host response in dogs. Neutrophils form part of the innate immune response and contains myeloperoxidase (MPO) as the predominant component of the neutrophil lysosomal protein in azurophilic granules. The neutrophil myeloperoxidase index (MPXI), determined on the ADVIA hematology analyzer, is a quantitative estimate of intracellular MPO content. Objectives of this study were to: (a) compare MPXI in dogs with babesiosis with healthy control dogs; (b) compare MPXI in dogs that died from babesiosis with dogs that survived and controls; and (c) correlate the MPXI with the previously determined segmented and band neutrophil count and cytokine concentrations in dogs with babesiosis. Data for 140 dogs naturally infected with B. rossi and 20 healthy control dogs were retrospectively evaluated. Neutrophil counts and MPXI were determined on an ADVIA 2120 analyzer. Cytokine concentrations [interleukin (IL)-2, IL-6, IL-8, IL-10, IL-18, granulocyte-macrophage colony stimulating factor (GM-CSF), and monocyte chemo-attractant protein-1 (MCP-1)] were determined using a canine-specific multiplex immunoassay. The mortality rate of the Babesia-infected dogs was 11% (15/140). MPXI was significantly higher in Babesia-infected dogs (P = 0.033), and in Babesia-infected non-survivors (P = 0.011), compared with healthy control dogs. In Babesia-infected dogs a significant positive correlation was found between MPXI and IL-10 (r = 0.211, P = 0.039) and a significant negative correlation was found between MPXI and IL-8 (r = -0.350, P < 0.001). In Babesia-infected non-survivors, significant positive correlations were found between MPXI and IL-2 (r = 0.616, P = 0.033), IL-6 (r = 0.615, P = 0.033), IL-18 (r = 0.613, P = 0.034), GM-CSF (r = 0.630, P = 0.028), and MCP-1 (r = 0.713, P = 0.009). In Babesia-infected survivors, a significant negative correlation was found between MPXI and IL-8 (r = -0.363, P = 0.001). MPXI was correlated with pro-inflammatory cytokines in Babesia-infected dogs that died. The potential of MPXI as a novel marker of inflammation and prognosis in dogs infected with B. rossi, thus warrants further investigation.

Pre- and post-therapy circulating immuno-stimulatory and immuno-suppressive cytokines in dogs with juvenile-onset generalized demodecosis

Overproliferation of Demodex mites in dogs with compromised immunity attributed to the development of canine demodecosis. Whether clinical signs of canine demodecosis are triggered by genetically-mediated specific immunodeficiency in dogs or the Demodex mites induce lesions in hair follicles and result in compromised immunity is yet to be fully explored. To unravel the concealments of immunosuppression in canine demodecosis the present study was aimed to estimate the levels of circulating cytokines, pre- and post-therapy in nine dogs with juvenile-onset generalized demodecosis. At day 60 post-therapy of recommended amitraz rinse, significant (p ≤ 0.02) reduction in circulating IL-10 level was observed compared to its level before the start of the therapy (day 0). However, significant alterations in circulating levels of TNF-α and IFN-γ were not observed in these dogs at day 60 post-therapy as compared to their day 0 levels. A strong positive correlation between circulating level of IL-10 and mites population was observed both on day 0 (r² = 0.656; p ≤ 0.005) and day 60 post-therapy (r² = 0.575; p ≤ 0.018). Therefore, our findings suggest that Demodex mites induce immunosuppression in dogs during clinical disease and mites burden seems to be responsible for the development of generalized demodecosis.