Annemarie T. Kristensen

Thromboelastographic Evaluation of Hemostatic Function in Dogs with Disseminated Intravascular Coagulation

BACKGROUND There is considerable variation in the coagulation profile of dogs with disseminated intravascular coagulation (DIC), making it difficult to assess overall hemostatic function. OBJECTIVES To characterize the overall hemostatic state in dogs with DIC, by use of tissue factor-activated thromboelastography (TF-TEG), and to determine whether there is an association between hemostasis and outcome. ANIMALS 50 dogs with DIC. METHODS Dogs admitted to the intensive care units, with an underlying disease known to predispose to DIC, were prospectively assessed with TF-TEG. Citrated blood samples were collected daily during hospitalization and an extended coagulation panel and TF-TEG were performed. Diagnosis of DIC was based on expert opinion. RESULTS Hemostatic dysfunction was observed on the TF-TEG profile in 33/50 of the dogs, of which 22/50 were hypercoagulable and 11/50 were hypocoagulable based on the TF-TEG G value alone. There were significant differences in k, alpha, and MA values (P < .0001) among hypo-, normo-, and hypercoagulable dogs. There was a significant difference in case fatality rate between hypo- (64%) and hypercoagulable (32%) dogs (relative risk = 2.38; P= .04). Dogs that died had significantly lower antithrombin activity (P= .03) and higher d-dimer concentration (P= .03) than survivors. CONCLUSIONS The most common overall hemostatic abnormality in dogs diagnosed with DIC was hypercoagulability, and there was significant difference in survival between hyper- and hypocoagulable dogs. The results suggest TF-TEG is valuable in the assessment of hemostatic function in dogs diagnosed with DIC.

Evaluation of human recombinant tissue factor-activated thromboelastography in 49 dogs with neoplasia.

BACKGROUND Abnormal routine coagulation assay results have been reported to be common in veterinary patients with neoplasia, but the overall hemostatic functional state, including hypercoagulability, has not been described. HYPOTHESIS The overall hemostatic functional state, including hypercoagulability, can be assessed in dogs with neoplasia by tissue factor (TF)-activated thromboelastography (TEG). ANIMALS Thirty-six dogs with malignant neoplasia and 13 dogs with benign neoplasia presented to the Small Animal Veterinary Teaching Hospital, The University of Copenhagen, Frederiksberg, Denmark. METHODS Prospective study evaluating the overall hemostatic functional state in dogs with neoplasia by a newly validated TF-activated TEG assay and routine coagulation parameters activated partial thromboplastin time (aPTT), prothrombin time (PT), platelet count, and D-dimer concentration. RESULTS Hemostatic dysfunction was observed in 28/49 (57%) dogs with neoplasia. Twenty-four were dogs with malignant neoplasia, the majority of which 18/36 (50%) were hypercoagulable, whereas 6/36 (17%) were hypocoagulable. All hypocoagulable dogs had metastatic disease. The proportion of dogs with altered hemostasis was significantly different between dogs with malignant and benign neoplasia. CONCLUSIONS AND CLINICAL IMPORTANCE TF-activated TEG detected hypercoagulable and hypocoagulable states in this population of dogs with neoplasia. The most common hemostatic abnormality in dogs with malignant neoplasia was hypercoagulability. These findings suggest that this novel hemostatic function test may be of value as a cage side method for the assessment of overall hemostatic function in dogs with cancer, including the detection of both hyper- and hypocoagulable states as well as mixed disorders.

Positron Emission Tomography Based Elucidation of the Enhanced Permeability and Retention Effect in Dogs with Cancer Using Copper-64 Liposomes

Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years was considered to be a ubiquitous phenomenon. However, the understanding of differences in the EPR-effect between tumor types, heterogeneities within each patient group, and dependency on tumor development stage in humans is sparse. It is therefore important to enhance our understanding of the EPR-effect in large animals and humans with spontaneously developed cancer. In the present paper, we describe a novel loading method of copper-64 into PEGylated liposomes and use these liposomes to evaluate the EPR-effect in 11 canine cancer patients with spontaneous solid tumors by PET/CT imaging. We thereby provide the first high-resolution analysis of EPR-based tumor accumulation in large animals. We find that the EPR-effect is strong in some tumor types but cannot be considered a general feature of solid malignant tumors since we observed a high degree of accumulation heterogeneity between tumors. Six of seven included carcinomas displayed high uptake levels of liposomes, whereas one of four sarcomas displayed signs of liposome retention. We conclude that nanocarrier-radiotracers could be important in identifying cancer patients that will benefit from nanocarrier-based therapeutics in clinical practice.

The influence of platelets, plasma and red blood cells on functional haemostatic assays.

Functional whole blood haemostatic assays are used increasingly to guide transfusion therapy and monitor medical treatment and are also applied for in-vitro evaluations of the haemostatic potential of stored platelets. We investigated how the cellular and plasmatic elements, both isolated and combined, influenced the two methodologically different assays, thrombelastography (TEG) and impedance aggregometry (Multiplate). Platelet-rich plasma (200 × 109/l) or pure plasma (0 platelets), with and without added red blood cells (RBCs), hematocrit 0, 0.15 or 0.29, were produced in vitro from platelet concentrates, fresh frozen plasma and stored RBC. Pure platelets were investigated by removing plasma components from platelet concentrates by diafiltration against the platelet storage solution Intersol. Plasma was readded by diafiltration against plasma in Intersol. Haemostatic function was evaluated by TEG and Multiplate. In the TEG, increasing amounts of RBC reduced clot strength and clot kinetics (α-angle), most markedly in plasma/RBC without platelets. In contrast, RBC in a platelet concentrate matrix enhanced Multiplate aggregation in response to weak agonists (ADP and arachidonic acid). Furthermore, removing plasma from platelet concentrates eliminated the TEG response and diminished the Multiplate aggregation response, but readding plasma to the pure platelet concentrates restored the response. Each of the elements in whole blood, plasma, platelets and RBC, affected the Multiplate and TEG results differently. The results emphasize that the concentrations of all cellular and plasmatic components in whole blood should be taken into account when interpreting results obtained by TEG and multiplate.

Data from the Danish Veterinary Cancer Registry on the occurrence and distribution of neoplasms in dogs in Denmark

From May 15, 2005 to April 15, 2008, 1878 cases of neoplasms in dogs were reported to the web-based Danish Veterinary Cancer Registry. The proportions of malignant (38 per cent) and benign (45 per cent) tumours were similar. The most common malignant neoplasms were adenocarcinomas (21 per cent), mast cell tumours (19 per cent) and lymphomas (17 per cent). The benign neoplasms most commonly encountered were lipomas (24 per cent), adenomas (22 per cent) and histiocytomas (14 per cent). Skin (43 per cent) and the female reproductive system including mammary tissue (28 per cent) were the most common locations of neoplasia. There was a distinct breed predisposition for tumour development, with a high standard morbidity ratio (indicating a higher risk of cancer) for boxers and Bernese mountain dogs. A standard morbidity ratio below 1 was observed in German shepherd dogs and Danish/Swedish farm dogs, suggesting a lower risk of cancer in these breeds.

IL-1β, IL-6, KC and MCP-1 are elevated in synovial fluid from haemophilic mice with experimentally induced haemarthrosis

Summary.  The hallmark of haemophilia is the joint morbidity resulting from haemarthrosis that accounts for the majority of the bleeds. The exact mechanisms underlying changes are not fully elucidated. Cytokines are speculated to be involved in the progression and in vitro studies have confirmed the presence of elevated levels of cytokines in synovial tissue and cartilage from patients with haemophilic synovitis. In this study, the presence of selected cytokines in synovial fluid from haemophilia A mice with experimentally induced haemarthroses treated with rFVIII, rFVIIa and an rFVIIa analogue were investigated. Ten cytokines previously shown to be involved in arthritic syndromes were evaluated. Interleukin (IL)‐1β, IL‐2, IL‐4, IL‐6, IL‐10, IL‐17, Tumor Necrosis Factor‐alpha (TNF‐ α), keratinocyte‐derived chemokine (KC), Regulated upon Activation, Normal T cell Expressed and Secreted (RANTES) and monocyte chemotactic protein‐1 (MCP‐1) were included. In this article, we demonstrate, for the first time, that bleeding in knee joints of haemophilia A mice resulted in correlated increased levels of the pro‐inflammatory cytokines: IL‐1β, IL‐6, KC and the MCP‐1 in synovial fluid. These results suggest an important role of MCP‐1 in the recruitment of monocytes and furthermore that the inflamed synovium releases IL‐1β, IL‐6 and KC, which in turn might contribute to further progression of the inflammatory process.

Thromboelastography results on citrated whole blood from clinically healthy cats depend on modes of activation.

BackgroundDuring the last decade, thromboelastography (TEG) has gained increasing acceptance as a diagnostic test in veterinary medicine for evaluation of haemostasis in dogs, however the use of TEG in cats has to date only been described in one previous study and a few abstracts. The objective of the present study was to evaluate and compare three different TEG assays in healthy cats, in order to establish which assay may be best suited for TEG analyses in cats.Methods90 TEG analyses were performed on citrated whole blood samples from 15 clinically healthy cats using assays without activator (native) or with human recombinant tissue factor (TF) or kaolin as activators. Results for reaction time (R), clotting time (K), angle (α), maximum amplitude (MA) and clot lysis (LY30; LY60) were recorded.ResultsCoefficients of variation (CVs) were highest in the native assay and comparable in TF and kaolin activated assays. Significant differences were observed between native and kaolin assays for all measured parameters, between kaolin and TF for all measured parameters except LY60 and between native and TF assays for R and K.ConclusionThe results indicate that TEG is a reproducible method for evaluation of haemostasis in clinically healthy cats. However, the three assays cannot be used interchangeably and the kaolin- and TF activated assays have the lowest analytical variation indicating that using an activator may be superior for performing TEG in cats.

Investigation of the thrombin‐generating capacity, evaluated by thrombogram, and clot formation evaluated by thrombelastography of platelets stored in the blood bank for up to 7 days

Background and Objectives  Transfusion based on the Thrombelastograph (TEG®) results reduces transfusion requirements in cardiac surgery and in liver transplantation. Taking the pivotal role of thrombin generation in the coagulation process into consideration, the clinical utility of the TEG may, in part, depend on its reflection of the dynamics of thrombin generation.

Thromboelastography in Veterinary Medicine

Thromboelastography (TEG) has been used in experimental animal studies since the early 1960s and in a routine clinical setting for the past decade. From the data currently available, it is clear that both the scope and limitations of TEG in animals resemble those observed in humans. TEG has been used to diagnose hypercoagulability in animals with disseminated intravascular coagulation, various types of cancer, and critical illness. Its ability to detect and monitor animals with various types of coagulopathies has been well established, both clinically and in experimental studies. TEG is often used in animals to monitor the effect of different pro- and anticoagulant drugs and often performs better at this task than conventional coagulation assays. TEG is already well established in veterinary medicine, and with the rapid dissemination of the technique currently taking place, we can expect to see a wide variety of interesting animal data published in the near future.

Evaluation of a nine-point body condition scoring system in physically inactive pet cats.

OBJECTIVE To compare results of body condition scoring by use of a 9-point scale with body composition determined by dual-energy x-ray absorptiometry (DEXA) in indoor-confined neutered domestic shorthair (DSH) pet cats. Animals-72 indoor-confined, adult neutered DSH pet cats (38 females and 34 males). PROCEDURES All cats underwent a physical examination including assessment of body weight (BW), body condition score (BCS; 1 = emaciated, 5 = ideal, and 9 = grossly obese), and girth. Urinalysis, CBC, and serum biochemical analysis were also performed. After the cats were confirmed healthy, they were anesthetized for body composition measurement via DEXA. Lean body mass, fat mass, and percentage body fat (%BF) were then evaluated. RESULTS The correlation between %BF and BCS (r = 0.87) was superior to the correlations between %BFand BW (r = 0.74) and between %BF and girth (r = 0.78). Values for %BF differed significantly between all pairs of BCSs except BCSs 8 and 9. Within a BCS, the %BF was similar for male and female cats. The mean %BF for cats with a BCS of 5 was 32, which exceeded the upper reference limit of %BF generally considered ideal (30). CONCLUSIONS AND CLINICAL RELEVANCE The 9-point BCS scale appears useful for assessing %BF in DSH pet cats. Nevertheless, study findings could indicate a need for redefining the ideal BCS for inactive neutered cats to include a BCS of 4.