Interleukin-6 as a prognostic marker in dogs in an intensive care unit

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.

Inhibiting IL-6 in medicine: a new twist to sustain inhibition of his cytokine tin the therapy of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a chronic, progressive disease characterized by an increase in blood pressure in the lungs' arteries. It can occur in a variety of species, including humans, dogs, cats, and horses. To date, PAH has a high mortality rate in both veterinary and human medicine, often due to complications such as heart failure. The complex pathological mechanisms of PAH involve multiple cellular signalling pathways at various levels. IL-6 is a powerful pleiotropic cytokine that regulates several phases of immune response, inflammation, and tissue remodelling. The hypothesis of this study was that the use of an IL-6 antagonist in PAH could interrupt or mitigate the cascade of events that leads to the progression of the disease and the worsening of clinical outcome, as well as tissue remodelling. In this study, we used two pharmacological protocols with an IL-6 receptor antagonist in a monocrotaline-induced PAH model in rats. Our results showed that the use of an IL-6 receptor antagonist had a significant protective effect, ameliorating both haemodynamic parameters, lung and cardiac function, tissue remodelling, and the inflammation associated with PAH. The results of this study suggest that the inhibition IL-6 could be a useful pharmacological strategy in PAH, in both human and veterinary medicine.

Effect of Cannabidiol (CBD) on Canine Inflammatory Response: An Ex Vivo Study on LPS Stimulated Whole Blood

The use of cannabidiol (CBD) for animal species is an area of growing interest, for example for its anti-inflammatory and immuno-modulating properties, even though all of its biological effects are still not fully understood, especially in veterinary medicine. Therefore, the aim of this study was to investigate the anti-inflammatory and immuno-modulating properties of CBD for the first time directly in canine inflammatory response. We used an ex vivo model of LPS-stimulated whole dog blood. We stimulated the whole blood from healthy dogs with LPS 100 ng/mL for 24 h in the presence or not of CBD 50 and 100 μg/mL. We observed a reduction in IL-6 and TNF-α production from the group treated with CBD, but non-altered IL-10 levels. Moreover, we also observed from the CBD-treated group a reduction in Nf-κB and COX-2 expression. In conclusion, we demonstrated for the first time the anti-inflammatory and immuno-modulating properties of CBD directly in dogs' immune cells, using a canine ex vivo inflammatory model. The results obtained from these studies encourage further studies to better understand the possible therapeutic role of CBD in veterinary medicine.

Adiponectin as a sepsis biomarker in dogs: Diagnostic and prognostic value

BACKGROUND

Adiponectin (ADPN) is an adipocytokine with insulin-sensitizing, vascular-protective, and anti-inflammatory properties for which concentration changes occur in response to inflammation. Little is known about the regulation of ADPN and the impact of this adipocytokine in septic dogs.

OBJECTIVE

We aimed to assess the diagnostic and prognostic value of ADPN vs other traditional acute-phase proteins (APPs), such as albumin (ALB), haptoglobin (HPT), fibrinogen (FBG), ferritin (FRT), and C-reactive protein (CRP) in dogs with naturally acquired sepsis.

METHODS

This prospective observational study included 20 dogs with sepsis, 27 with low-grade systemic inflammation (LGSI), and 18 clinically healthy dogs as controls. For method analyses, plasma samples were obtained from all dogs on admission and then every 24-48 hours until discharge or death in the septic group.

RESULTS

Septic dogs had lower ADPN (2.4 ± 0.46 vs 4.5 ± 0.41mg/L, P < .001) dand ALB (17 ± 1 vs 22 ± 0.8g/L, P = .002), and tended to have higher CRP (87 ± 4.8 vs 73 ± 4.1mg/L, P < .079) concentrations than dogs with LGSI on admission. Only ADPN and ALB were able to successfully discriminate animals with LGSI from those presenting with sepsis with areas under the curve (AUCs) for the receiver operating characteristic (ROC) curves of 0.811 and 0.789, respectively. In the septic group, ADPN concentration did not differ between survivors and non-survivors, either on admission or at discharge or death.

CONCLUSIONS

Although plasma ADPN can be used as a reliable negative APP in dogs with sepsis, further studies are warranted to confirm the usefulness of this biomarker in terms of disease progression and recovery.

The effect of ammonia on canine polymorphonuclear cells

Hyperammonaemia is a common complication of liver disease in dogs. High concentrations of ammonia can be detrimental to dogs with liver disease for several reasons, notably by causing hepatic encephalopathy (HE) which describes the wide range of neurological abnormalities ranging from altered behaviour to seizures that are well recognised complications in dogs with hepatic disorders. In human patients with liver disease, hyperammonaemia has also been linked to the development of other systemic complications such as dysregulation of the innate immune system. In contrast, the effects of hyperammonaemia on the canine innate immune system is currently unknown. The aim of this study was to investigate the effects of ammonia on the oxidative burst activity of canine polymorphonuclear cells in vitro. Blood obtained from healthy dogs (n = 8) was incubated with escalating concentrations of ammonia ranging from 0 to 250 μM, and the percentage of cells experiencing an oxidative burst was evaluated using a commercial kit (Phagoburst™) and flow cytometry. The spontaneous oxidative burst was evaluated without stimulation and also following stimulation with E coli. The pH of the blood was also measured at the differing ammonia concentrations. There was an increase in the percentage of cells experiencing a spontaneous oxidative burst from ammonia concentrations of 125 μM (p = <0.05) and above (p = <0.01), with a 4.9 fold increase at 200 μM (p = < 0.001). In those cells stimulated with E coli, incubation with increasing ammonia concentrations did not result in a significant difference in oxidative burst from baseline (p = 0.953). There was no statistically significant difference between the pH of the blood at the various ammonia concentrations (p = 0.2) suggesting that the difference in spontaneous oxidative burst was due to the ammonia rather than simply a change in pH conditions. In summary, the spontaneous oxidative burst of neutrophils was significantly increased from baseline. This supports a potential role of ammonia in contributing to innate immune system dysfunction in dogs with liver disease, and may present a future therapeutic target.

Evaluation of potential serum biomarkers of hepatic fibrosis and necroinflammatory activity in dogs with liver disease

Background

Serum interleukin 6 (IL‐6), chemokine ligand 2 (CCL2), C‐reactive protein (CRP), and the ratio of aspartate transaminase to alanine transaminase (AST:ALT) have been correlated with fibrosis and necroinflammatory activity in humans with various hepatopathies.

Hypothesis/Objectives

To determine whether increases in serum IL‐6, CCL2, CRP, or AST:ALT were associated with moderate to severe fibrosis or necroinflammatory activity in dogs with various hepatopathies.

Animals

Forty‐four client‐owned dogs with clinical evidence of liver disease and 10 healthy purpose‐bred dogs, all undergoing liver biopsies by laparoscopy or laparotomy.

Methods

Measurement of serum IL‐6, CCL2, CRP, AST, and ALT before scheduled liver biopsy and evaluation of liver histopathology using the METAVIR scoring system used in human medicine, blinded to clinical presentation.

Results

Median serum IL‐6 was approximately twice as high in dogs with high fibrosis scores (15.5 pg/mL; range, 1.4 to 235 pg/mL) compared to dogs with low fibrosis scores (7.6 pg/mL; range, 1.4 to 148.1 pg/mL), with marginal significance (P = .05). Median serum CCL2 was significantly higher in dogs with active necroinflammation (444 pg/mL; range, 144 to 896 pg/mL) compared to dogs without detectable necroinflammation (326 pg/mL; range, 59 to 1692 pg/mL; P = .008), but with considerable overlap between groups. Neither serum CRP nor AST:ALT ratios were significantly different based on fibrosis or necroinflammatory scores.

Conclusions and Clinical Importance

Because of substantial variability among dogs, single measurements of IL‐6 and CCL2 have limited diagnostic utility for identifying fibrosis or necroinflammation, respectively, in dogs with various chronic liver diseases. The value of these biomarkers should be explored further in monitoring response to treatment in individual dogs with chronic hepatopathies.

Treatment with 24 h-delayed normo- and hyperbaric oxygenation in severe sepsis induced by cecal ligation and puncture in rats

Background

Septic shock remains a leading cause of death worldwide. Hyperbaric oxygen treatment (HBO₂) has been shown to alter the inflammatory response during sepsis and to reduce mortality. A therapeutic window of HBO₂ treatment has been demonstrated experimentally, but optimal timing remains uncertain. We investigated the effects of 24 h delayed normobaric oxygen (NBO₂) and HBO₂ treatment on the endogenous production of the inflammatory markers interleukin (IL)-6, tumor necrosis factor (TNF)-α and IL-10, and on mortality in rats with cecal ligation and puncture (CLP) induced sepsis.

Method

Fifty-five male Sprague-Dawley rats underwent CLP and were randomized to the following groups: 1) HBO₂ 2.5 bar absolute pressure (p_abs); 2) NBO₂ 1.0 bar p_abs; 3) Control (no-treatment), and they were individually monitored for 72 h with intermittent blood sampling.

Results

IL-6, TNF-α, and IL-10 were increased 24 h after the procedure, and IL-6 was significantly higher in non-survivors than in survivors. The level of IL-10 was significantly higher at hour 48 in the HBO₂ group compared to control (p = 0.01), but this was not the case at other time points. No other significant differences in cytokine levels were found for any group comparisons. Delayed NBO₂ and HBO₂ treatment failed to change the mortality in the animals.

Conclusion

High levels of IL-6 in non-surviving animals with sepsis suggest that IL-6 is a potential biomarker. We found a significantly higher concentration of IL-10 in the HBO₂ group at hour 48 vs. control animals. However, 24 h–delayed treatment with HBO₂ did not change the levels of pro-inflammatory cytokines and survival, suggesting that earlier intervention may be required to obtain an anti-inflammatory effect.

Evaluation of cardiopulmonary and inflammatory markers in dogs with heartworm infection during treatment with the 2014 American Heartworm Society recommended treatment protocol

Background

Heartworm disease in dogs is a life-threatening parasitic disease. Although adulticide treatment with melarsomine has been proven to be the most effective, complications associated with adulticide treatment are major concerns for clinicians.

Methods

This study evaluated the change in levels of D-dimer, interleukin-6, C-reactive protein and cardiac troponin I in 12 dogs with different severities of heartworm infection treated by the American Heartworm Society (AHS) recommended protocol during the treatment period. The serum levels of several markers were measured on the day of diagnosis (T-60), before the initiation of melarsomine therapy (T0), 1 day after the first injection (T1), 1 week after the first injection (T7), 1 month after the first injection (T30), 1 day after the second injection (T31), 1 day after the third injection (T32), 1 week after the third injection (T39), 1 month after the third injection (T62), 2 months after the third injection (T92), 3 months after the third injection (T122), and 6 months after the third injection (T182).

Results

The serum levels of these markers were significantly different at the test time point after melarsomine treatment and also differed significantly according to the stage of heartworm disease in the dogs.

Conclusion

This study found that monitoring of inflammatory and hemostatic markers in dogs with heartworm disease being treated with melarsomine might be beneficial in predicting the clinical outcomes and complications associated with melarsomine treatment.

Serum alpha1 -proteinase inhibitor concentrations in dogs with systemic inflammatory response syndrome or sepsis

OBJECTIVE

To determine whether the concentration of serum canine alpha₁ -proteinase inhibitor (cα₁ -PI) has diagnostic or prognostic utility in dogs with sepsis or noninfectious systemic inflammatory response syndrome (SIRS).

DESIGN

Prospective, observational study from May to December 2010.

SETTING

University teaching hospital ICU.

ANIMALS

Sixty-nine client-owned dogs: 19 dogs with SIRS or sepsis and 50 healthy control dogs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Serum and plasma samples were collected from dogs with SIRS or sepsis on the day of hospital admission and once on the following 2 days, and on a single day in healthy controls. Patients were assessed using the 10-parameter Acute Patient Physiologic and Laboratory Evaluation (APPLE_full ) and 5-parameter (APPLE_fast ) score. Serum cα₁ -PI concentrations were measured, compared among groups of dogs, and evaluated for a correlation with the concentration of serum C-reactive protein, plasma interleukin-6, tumor necrosis factor-α, the APPLE scores, and survival to discharge. Serum cα₁ -PI concentrations were significantly lower in dogs with SIRS/sepsis (P < 0.001) than in healthy controls. While day 1 serum cα₁ -PI concentrations did not differ between dogs with SIRS and those with sepsis (P = 0.592), septic dogs had significantly lower serum cα₁ -PI concentrations on days 2 (P = 0.017) and 3 (P = 0.036) than dogs with SIRS. Serum cα₁ -PI concentrations did not differ between survivors and nonsurvivors (P = 1.000), but were inversely correlated with the APPLE_full score (ρ = -0.48; P = 0.040) and plasma interleukin-6 concentrations (ρ = -0.50; P = 0.037).

CONCLUSIONS

These results suggest a role of cα₁ -PI as a negative acute phase protein in dogs. The concentration of serum cα₁ -PI at the time of hospital admission does not have utility to identify dogs with sepsis from those with noninfectious SIRS, but may be a useful surrogate marker for early stratification of illness severity.

Evaluation of cardiopulmonary and inflammatory markers in dogs with heartworm infection treated using the slow kill method

This study evaluated the changes in the levels of cardiac, hemostatic, and inflammatory biomarkers in 12 dogs with different severities of heartworm infection treated using the slow kill protocol, consisting of 6-10μg/kg of ivermectin and 10mg/kg of doxycycline combination. The serum levels of cardiac troponin-I, D-dimer, C-reactive protein, and interleukin-6 were measured on the day of diagnosis (D0), after termination of doxycycline administration (D30), after termination of the slow kill treatment (D180), and 10 months after the initiation of therapy (D300). Heartworm antigenemia was cleared in 4/4 class I dogs, 3/4 class II dogs, and 1/4 class III dogs at the end of the therapy (D180), and in 4/4 class I, 4/4 class II, and 1/4 class III dogs at the end of the study (D300). The serum levels of the markers in class I dogs on the day of diagnosis (D0) were within the reference range, while the levels in class II and III dogs were above the reference range. Further, the serum levels of the markers in all dogs decreased significantly at the end of the study (D300), although some markers in class III dogs remained at pathological levels. This study revealed that the slow kill method should be used only as an alternative therapeutic protocol for dogs with low worm burden (class I and II). As the slow kill method alone may not effectively reduce all pathological changes in dogs with heavy worm burden and severe clinical signs (class III), adjuvant therapies including steroids and anti-thromboembolics should be used to minimize the risk of complications.

Serum interleukin-6 as a prognostic marker in neonatal calf diarrhea

Neonatal calf diarrhea is still one of the most important diseases in calf rearing, and severe diarrhea has a marked effect on animal welfare. Furthermore, significant economic losses can result from this disease due to high mortality rates, high medical costs, and low weight gain. To avoid a fatal outcome of the disease, it is crucial that vulnerable calves are identified as early as possible. Interleukin-6 is described as an early and reliable prognostic marker in several diseases. In this study, 20 scouring calves were tested by ELISA for their IL-6 serum concentrations. Samples were collected twice, at the beginning of diarrhea and 7 to 10 d later. Regarding the clinical outcome after 7 to 10 d, calves were classified as recovered or nonrecovered. A receiver operating characteristic analysis was conducted to determine the prognostic value of IL-6 for the progress of clinical symptoms. At the beginning of diarrhea, the IL-6 concentration was significantly higher in nonrecovering calves compared with those that recover 7 to 10 d after the onset of diarrhea. Interleukin-6 proved to be a useful additional parameter in the clinical examination. High initial IL-6 values can support the decision for closer monitoring and an adapted therapeutic strategy for the respective calves. This may help to prevent unnecessary animal suffering and reduce economic losses.

Presence of Systemic Inflammatory Response Syndrome Predicts a Poor Clinical Outcome in Dogs with a Primary Hepatitis

Primary hepatopathies are a common cause of morbidity and mortality in dogs. The underlying aetiology of most cases of canine hepatitis is unknown. Consequently, treatments are typically palliative and it is difficult to provide accurate prognostic information to owners. In human hepatology there is accumulating data which indicates that the presence of systemic inflammatory response syndrome (SIRS) is a common and debilitating event in patients with liver diseases. For example, the presence of SIRS has been linked to the development of complications such as hepatic encephalopathy (HE) and is associated with a poor clinical outcome in humans with liver diseases. In contrast, the relationship between SIRS and clinical outcome in dogs with a primary hepatitis is unknown. Seventy dogs with histologically confirmed primary hepatitis were enrolled into the study. Additional clinical and clinicopathological information including respiratory rate, heart rate, temperature, white blood cell count, sodium, potassium, sex, presence of ascites, HE score, alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin and red blood cell concentration were available in all cases. The median survival of dogs with a SIRS score of 0 or 1 (SIRS low) was 231 days compared to a median survival of 7 days for dogs with a SIRS score of 2, 3 or 4 (SIRS high) (p<0.001). A Cox proportional hazard model, which included all other co-variables, revealed that a SIRS high score was an independent predictor of a poor clinical outcome. The effect of modulating inflammation on treatment outcomes in dogs with a primary hepatitis is deserving of further study.