Stability and profiling of urinary microRNAs in healthy cats and cats with pyelonephritis or other urological conditions.

BACKGROUND: Specific biomarkers of pyelonephritis (PN) in cats are lacking. MicroRNAs (miRNAs) have diagnostic potential in human nephropathies. OBJECTIVES: To investigate the presence/stability of miRNAs in whole urine of cats and the discriminatory potential of selected urinary miRNAs for PN in cats. ANIMALS: Twelve healthy cats, 5 cats with PN, and 13 cats with chronic kidney disease (n = 5), subclinical bacteriuria (n = 3), and ureteral obstructions (n = 5) recruited from 2 companion animal hospitals. METHODS: Prospective case-control study. Expression profiles of 24 miRNAs were performed by quantitative PCR (qPCR). Effect of storage temperature (4°C [24 hours], -20°C, and -80°C) was determined for a subset of miRNAs in healthy cats. RESULTS: Urinary miR-4286, miR-30c, miR-204, miR4454, miR-21, miR-16, miR-191, and miR-30a were detected. For the majority of miRNAs tested, storage at 4°C and -20°C resulted in significantly lower miRNA yield compared to storage at -80°C (mean log2fold changes across miRNAs from -0.5 ± 0.4 SD to -1.20 ± 0.4 SD (4°C versus -80°C) and from -0.7 ± 0.2 SD to -1.20 ± 0.3 SD (-20°C versus -80°C)). Cats with PN had significantly upregulated miR-16 with a mean log2fold change of 1.0 ± 0.4 SD, compared with controls (-0.1 ± 0.2, P = .01) and other urological conditions (0.6 ± 0.3, P = .04). CONCLUSIONS: Upregulation of miR16 might be PN-specific, pathogen-specific (Escherichia coli), or both.

Subclinical bacteriuria in a mixed population of 179 middle-aged and elderly cats: a prospective cross-sectional study.

OBJECTIVES: Subclinical bacteriuria (SBU) is the presence of bacteria in urine with no clinical evidence of lower urinary tract disease. The aims of this study were to investigate if being overweight and/or obesity predispose cats to SBU, to investigate previously reported risk factors and to determine the prevalence of SBU in a prospectively sampled cohort of middle-aged and elderly cats. METHODS: Cats aged ⩾6 years presenting to the University Hospital for Companion Animals in Copenhagen from 2015-2019 for causes unrelated to the lower urinary tract were eligible for enrolment. Body condition scoring was performed on a 9-point scale. Overweight was defined as a body condition score (BCS) ⩾6 and obese as a BCS ⩾8. The correlation between SBU and the variables of sex, healthy/diseased, age, BCS and comorbidities (chronic kidney disease, diabetes mellitus, hyperthyroidism, hepatic disorders and gastrointestinal disease) were analysed by binominal logistic regression. RESULTS: In total, 179 cats ranging from 6-20 (median 10) years of age were included. SBU was identified in 11/179 cats (6.1%). Being overweight was not a significant risk factor (overweight/obese odds ratio [OR] 0.3, 95% confidence interval [CI] 0.06-1.6, relative risk [RR] 0.3 [95% CI 0.05-1.3] vs lean; P = 0.2) and neither was obesity compared with lean and overweight cats (P = 0.99). Female sex (OR 6.2 [95% CI 1.3-30], RR 4.7 [95% CI 1.5-12] vs male; P = 0.02) and the presence of hepatic disease (OR 7.5 [95% CI 1.4-39], RR 5.3 [95% CI 1.3-12]; P = 0.02) were significant risk factors. CONCLUSIONS AND RELEVANCE: The prevalence of SBU in cats is low, and being overweight/obese was not identified as a predisposing factor. The increased risk associated with hepatic disease has not been previously reported, and further studies are needed to confirm this finding.

Cardiac troponin I in cats with compromised renal function.

OBJECTIVES: Cardiac troponins are sensitive and specific markers of myocardial injury. However, their reliability in renal disease has been questioned owing to possible renal involvement in troponin elimination. The primary objective of the present study was to examine whether serum cardiac troponin I is elevated in cats with compromised renal function and no clinically relevant structural cardiac disease. A secondary objective was to examine whether cardiac troponin I is measurable in the urine of cats with normal and compromised renal function. METHODS: This prospective case-control study included 52 cats (19 with compromised renal function, 19 with primary cardiac disease and 14 healthy controls). For all cats, clinical examination, echocardiography, electrocardiography, blood pressure, complete blood count, biochemistry, serum thyroxine and urinalysis were performed. Cardiac troponin I was measured in the serum and urine of each cat. RESULTS: Median (range) serum cardiac troponin I concentrations were 0.052 ng/ml (0.015-0.78 ng/ml) for the renal group, 0.083 ng/ml (0.003-3.27 ng/ml) for the cardiac group and 0.012 ng/ml (0.003-0.14 ng/ml) for the control group. The renal and cardiac groups both had significantly higher serum cardiac troponin I concentrations than the control group, whereas no difference could be detected between the renal and cardiac groups. In the renal group 7/19 cats had measurable urine cardiac troponin I, whereas cardiac troponin I was measurable in the urine of one cat in the cardiac group and two healthy controls. There was no significant correlation between serum and urine cardiac troponin I. CONCLUSIONS AND RELEVANCE: Elevated serum cardiac troponin I in cats with compromised renal function may occur without evidence of clinically relevant structural cardiac disease. Moreover, detecting cardiac troponin I in urine is most likely in cats with compromised renal function.

In vitro heparinization of canine whole blood with low molecular weight heparin (dalteparin) significantly and dose-dependently prolongs heparinase-modified tissue factor-activated thromboelastography parameters and prothrombinase-induced clotting time.

BACKGROUND: Low-molecular-weight heparin (LMWH) is being used increasingly in veterinary medicine for both treatment and prophylaxis of thromboembolic disease, but no predictable patient-side method exists to monitor its effect. OBJECTIVES: The aim of this study was to evaluate thromboelastography (TEG) and prothombinase-induced clotting time (PiCT) assays for detecting hemostatic alterations following in vitro heparinization of canine whole blood with dalteparin (Fragmin). METHODS: Citrated whole-blood samples were collected from 7 clinically healthy dogs. Dalteparin was added at concentrations of 0, 0.156, 0.625, 1.25, and 2.5 U/mL of whole blood. TEG was performed using heparinase cups with tissue factor (TF, 1:50,000) and kaolin as activators. Reaction time (R), clotting time (K), angle (alpha), and maximum amplitude (MA) were recorded. PiCT and anti-FXa activity were measured in plasma. RESULTS: With TF, increasing concentrations of dalteparin significantly prolonged R and K and significantly decreased alpha and MA. K, alpha, and MA ratios were significantly different from baseline at all dalteparin concentrations and R was significantly different from baseline at concentrations of 0.625, 1.25, and 2.5 U/mL. With kaolin, only R was significantly different from baseline at dalteparin concentrations of 0.625 and 2.5 U/mL. PiCT detected dalteparin concentrations < or = 0.625 U/mL, with a good linear correlation (r(2)=.96, P<.0001). CONCLUSION: These results suggest that TF-activated TEG and PiCT assays should be further evaluated as promising new methods for evaluating the effect of LMWH, using doses in the recommended clinical range and prospective clinical studies.

Endogenous fibrinolytic potential in tissue-plasminogen activator-modified thromboelastography analysis is significantly decreased in dogs suffering from diseases predisposing to thrombosis.

BACKGROUND: In people, studies have shown that resistance to fibrinolysis could be a contributing factor to thrombosis. Tissue-plasminogen-activated (t-PA) thromboelastography (TEG) has been used to evaluate endogenous fibrinolytic potential. In dogs, TEG has been used for the diagnosis of various hemostatic disorders, but studies evaluating fibrinolysis are limited. Investigations into the potential of t-PA-modified TEG to monitor endogenous fibrinolytic potential are lacking in both healthy dogs and dogs with diseases predisposing to development of thrombosis. OBJECTIVES: The aim of this study was to compare 3 t-PA-modified TEG assays and compare the endogenous fibrinolytic potential in dogs suffering from diseases associated with thrombosis with a group of healthy dogs. METHODS: Three different TEG assays, such as native, tissue factor-activated, and kaolin-activated, were modified with t-PA and used to compare whole blood samples from 16 healthy control dogs and 20 diseased dogs. RESULTS: Thromboelastography lysis variables were significantly affected by addition of t-PA in all 3 assays. Lysis results in diseased dogs were comparable to those in healthy dogs prior to addition of t-PA. After addition of t-PA, lysis results were significantly decreased in the diseased group compared with healthy dogs. The lowest median lysis levels were found in dogs with systemic inflammation and protein-losing disorders. CONCLUSION: Addition of t-PA activates fibrinolysis in TEG of blood from both healthy dogs and dogs with diseases predisposing to thrombosis. The significantly decreased fibrinolysis in diseased dogs suggests that this may be a potential prothrombotic risk factor in dogs.

Diagnosis and treatment of platelet hyperactivity in relation to thrombosis in dogs and cats.

OBJECTIVE: To review the mechanisms of platelet activation and options for diagnosing and treating platelet hyperactivity in relation to thrombosis in dogs and cats. DATA SOURCES: Prospective, retrospective, and review articles, as well as textbook chapters in both human and veterinary medicine. Articles were primarily, but not exclusively, retrieved via Medline. HUMAN DATA SYNTHESIS: In people, platelets are known to play a key role in the development of arterial thrombosis in numerous disease states and antiplatelet drugs are the cornerstone in the treatment of acute events and for prevention in patients at risk. For many years, aspirin was used as the sole antiplatelet drug in people, but the introduction of adenosine diphosphate receptor antagonists and integrin α(IIb) ß(3) inhibitors has significantly improved outcome in selective groups of patients. VETERINARY DATA SYNTHESIS: The understanding of platelet activation in disease states has increased dramatically over the past decade. Simultaneously, a host of new methods for evaluating platelet function have been developed, which enable primarily researchers, but also clinicians to monitor the activity of platelets. Many of these methods have been validated for research purposes, but few have found their way to the clinics. Not a single correctly randomized clinical trial has been carried out with any antiplatelet drug for any indication in dogs or cats, and consequently, treatment is empiric and largely based on expert opinion or data from experimental studies. CONCLUSIONS: The pathogenesis of thromboembolic disease is complex and multifactorial and the role of hyperactive platelets in this etiology remains to be clarified in most of the diseases associated with thrombosis in dogs and cats. Until efficacy data from well-designed studies are available, antithrombotic therapy should consist of close monitoring, good supportive care, and judicious empirical use of antiplatelet agents.

Thrombin-activatable fibrinolysis inhibitor activity in healthy and diseased dogs.

BACKGROUND: In people, increased thrombin-activatable fibrinolysis inhibitor (TAFI) antigen has been associated with increased risk of thrombosis, and decreased TAFI may contribute to bleeding diathesis. TAFI activity in dogs has been described in experimental models, but not in dogs with spontaneous disease. OBJECTIVE: The aim of this study was to compare TAFI activity in healthy dogs with TAFI activity in dogs with spontaneous disease. METHODS: Plasma samples from 20 clinically healthy Beagles and from 35 dogs with various diseases were analyzed using a commercial chromogenic assay that measured TAFI activity relative to activity in standardized pooled human plasma. RESULTS: Median TAFI activity for the 20 Beagles was 46.1% (range 32.2-70.8%) compared with 62.6% (29.1-250%) for the 35 diseased dogs, and 14/35 (40%) had TAFI activities >the upper limit for controls. The highest individual activities (>225%) were in 3 dogs with malignant neoplasms and 1 dog with thrombocytopenia. For data grouped by diagnosis, median TAFI activity was 61.7% for benign neoplasia (n=5), 64.9% for malignant neoplasia (n=8), 75.5% for Angiostrongylus vasorum infection (n=4), 68.8% for bacterial sepsis (n=7), and 58.7% for miscellaneous diseases (n=11). Compared with TAFI activity in control dogs, median TAFI activity was significantly increased only in the group of dogs with bacterial sepsis. CONCLUSION: Bacterial sepsis was associated with significantly increased TAFI activity, and individual dogs with increased TAFI activities were found in all disease groups. The role of TAFI in the pathogenesis of hemostatic disorders in dogs and its value as a prognostic indicator deserve further investigation.