Hemostatic findings of pleural fluid in dogs and the association between pleural effusions and primary hyperfibrino(geno)lysis: A cohort study of 99 dogs

An Evaluation of Hemostatic Dysregulation in Canine Multicentric Lymphoma

Multiple hemostatic abnormalities are associated with paraneoplastic syndrome and some malignant tumors. Lymphoma is the most common hematopoietic neoplasm in dogs, sometimes associated with hemostatic changes. The objectives of this study were to evaluate the behavior of coagulation parameters in dogs with multicentric lymphoma compared with diseased dogs without lymphoma, to separately evaluate the effect of immunophenotype (B lymphoma versus T lymphoma) on the variables of interest as well as the effect of disease stage (stage II to IV versus stage V). Specifically, a cross-sectional study was performed with a matched comparison group considering 170 dogs with B or T lymphoma (group 1) and 170 dogs with no lymphoma or other neoplastic processes but other diseases (group 0). Eight coagulation parameters were evaluated: platelet count (Plt), activated partial thromboplastin time (aPTT), prothrombin time (PT), thrombin time (TT), fibrinogen, fibrin/products of fibrinogen degradation (FDPs), fibrin D-dimers, and antithrombin (AT). Dogs with lymphoma showed prolonged PT and TT, decreased fibrinogen, increased FDP, and decreased Plt compared with group 0. The effect of disease stage was evaluated separately for dogs with stage II to IV lymphoma and dogs with stage V lymphoma; patients with stage II-IV lymphoma showed no significant differences, while in dogs with stage V lymphoma, a prolongation of PT and TT, a decrease in fibrinogen, an increase in FDPs and a decrease in Plt were found compared with the group 0. Finally, the comparison between B lymphoma and T lymphoma showed no significant differences in coagulation parameters between the two groups. Logistic regression analysis demonstrated that low fibrinogen and platelet levels were the most significant predictors of lymphoma in a cohort of canine patients. These hemostatic abnormalities in lymphoma appeared to be associated with the stage of the disease rather than the lymphoma immunophenotype. These findings pave the way for the possible scenario of lymphoma-associated fibrinolysis and the so far undescribed pattern of hyperfibrinolysis associated with the most severe stage of lymphoma.

Fibrinolysis in Dogs with Intracavitary Effusion: A Review

Simple Summary

In blood vessels there is a balance between clot formation and its dissolution. Fibrinolysis normally allows the breakdown of blood clots during the healing of injured blood vessels. This process is mediated by the activation of a blood enzyme (plasmin) which breaks down a meshed protein (fibrin) which holds blood clots at the site of the vessel injury. In some diseases, the activation of plasmin becomes excessive, leading to bleeding tendencies (hyperfibrinolysis). Under normal conditions, abdominal and thoracic cavities are filled with a small amount of fluid deriving from the blood. The results of recent studies have shown that, in dogs, all types of pathologic intracavitary fluids have an increased fibrinolytic activity. This increased fibrinolytic activity is also present in their blood, in some cases reaching a hyperfibrinolytic state. Hyperfibrinolysis and bleeding tendencies have also been documented in cardiopathic dogs with ascites. The latter result is surprising considering that thrombotic events are commonly documented in humans and cats with some cardiac diseases.

Abstract

Physiologic fibrinolysis is a localized process in which stable fibrin strands are broken down by plasmin in response to thrombosis. Plasmin activation can also take place separately from the coagulation process, resulting in pathologic fibrinolysis. When plasmin activation exceeds the neutralizing capacity of plasmin inhibitors, severe bleeding can potentially take place. Although the processes which regulate coagulation and fibrinolysis in the blood are well known, it is less clear as to what extent the same processes take place in the body cavities and whether they influence systemic hemostasis. The results of the studies herein cited demonstrate that coagulation followed by fibrinogenolytic/fibrinolytic activity takes place in all kinds of canine ascitic and pleural fluids. Moreover, systemic clotting abnormalities suggesting primary fibrinolysis/primary hyperfibrinolysis (i.e., elevated plasma fibrin/fibrinogen degradation products [FDPs] and normal D-dimer concentrations with fibrinogen concentrations ≤ 100 mg/dL or above this cut-off, respectively) occur in dogs with intracavitary effusion. Enhanced fibrinolytic activity in dogs with intracavitary effusion can also be detected using rotational thromboelastometry (ROTEM), although the degree of agreement between ROTEM and FDPs, D-dimer and fibrinogen concentrations is poor. Finally, contrary to the thrombotic events commonly documented in some humans and cats with cardiac diseases, bleeding tendencies due to primary fibrinolysis/primary hyperfibrinolysis have been documented in dogs with cardiogenic ascites.

Reduced risk of arterial thromboembolism in cats with pleural effusion due to congestive heart failure

OBJECTIVES

The aim of the study was to determine whether cardiogenic pleural effusion in cats is associated with a lower risk of arterial thromboembolism (ATE) compared with cats with cardiac disease without evidence of pleural effusion.

METHODS

A cross-sectional study was conducted on owned cats with natural occurring cardiac diseases. Cats included were classified in three groups: those with cardiac disease but no evidence of congestive heart failure (CHF); those with evidence of cardiogenic pulmonary oedema; and those with evidence of cardiogenic pleural effusion. Prevalence of ATE was calculated and the variables analysed for an association with this outcome were the presence and type of CHF, sex and neuter status, age, breed, type of cardiac diseases and left atrial (LA) dimension. A multivariable logistic regression model was used to fit the association between ATE and these variables.

RESULTS

A total of 366 cats with cardiac disease met the inclusion criteria: 179 were included in the group with cardiac disease but no evidence of CHF, 66 in the group with evidence of cardiogenic pulmonary oedema and 121 in the group with evidence of cardiogenic pleural effusion. Prevalence of ATE (58/366 [15.8%]) was significantly different among groups (with no evidence of CHF, 28/179 [15.6%]; with evidence of cardiogenic pulmonary oedema, 22/66 [33.3%]; with evidence of cardiogenic pleural effusion, 8/121 [6.6%]; P <0.001). Cats with ATE had a significantly higher LA to aortic root ratio (2.30 ± 0.46) than those without ATE (2.04 ± 0.46; P <0.001). Multivariable logistic regression analysis indicated that the group with evidence of cardiogenic pleural effusion was associated with a lower risk of developing ATE compared with groups with cardiac disease but no evidence of CHF and with evidence of cardiogenic pulmonary oedema (P = 0.005 and P <0.001, respectively).

CONCLUSIONS AND RELEVANCE

Presence of cardiogenic pleural effusion is associated with a lower risk of developing ATE, while LA enlargement is a risk factor for ATE.

Low-soluble TREM-like transcript-1 levels early after severe burn reflect increased coagulation disorders and predict 30-day mortality

BACKGROUND

Patients with severe burns often show systemic coagulation changes in the early stage and even develop extensive coagulopathy. Previous studies have confirmed that soluble TREM-like transcript-1 (sTLT-1) mediates a novel mechanism of haemostasis and thrombosis in inflammatory vascular injury. At present, the role of sTLT-1 in patients with severe burns is not well known.

OBJECTIVE

To investigate the early association between sTLT-1 levels and markers of burn severity, coagulation disorders, endothelial permeability, shock and prognosis in patients with severe burns.

METHODS

A prospective, observational study was conducted with 60 severe burn patients (divided into a death group and a survival group according to 30-day prognosis) admitted to our hospital. Twenty-eight healthy volunteers were recruited as the control group. Blood components at 48 h after burn were analysed for sTLT-1 and biomarkers reflecting platelet activation, shock, endothelial glycocalyx damage, capillary leakage, haemostasis, fibrinolytic activity, natural anticoagulation and blood cells. We compared the three groups, analysed the correlation between sTLT-1 and biomarkers, and investigated the predictive value of sTLT-1 for 30-day prognosis.

RESULT

Compared with the surviving patients, the patients who died had a lower degree of platelet activation [lower sTLT-1, platelet factor 4 (PF-4) and platelet counts] and a higher degree of burn [higher abbreviated burn severity index score (ABSI score)], shock (higher lactate), endothelial glycocalyx damage [higher syndecan-1 and soluble thrombomodulin (sTM)] and capillary leakage [higher resuscitation fluid (0-48 h), lower albumin] as well as decreased haemostasis [higher activated partial prothrombin time (APTT), lower fibrinogen and thrombin-antithrombin III complex (TAT)], increased fibrinolytic activity [higher D-dimer and tissue-type plasminogen activator (tPA)] and decreased natural anticoagulation [lower protein C (PC) and protein S (PS)]. Higher D-dimer (P = 0.013) and lower PF-4 (P = 0.001) were significantly independently associated with lower sTLT-1. Low circulating sTLT-1 (a unit is 50 pg/mL) (odds ratio [OR] 2.08 [95% CI 1.11-3.92], P = 0.022) was an independent predictor of increased 30-day mortality.

CONCLUSION

Low sTLT-1 levels at 48 h after burn in patients with severe burns is associated with increased coagulation disorders. Low circulating sTLT-1 levels were an independent predictor of increased 30-day mortality.

Enhanced fibrinolysis detection in a natural occurring canine model with intracavitary effusions: Comparison and degree of agreement between thromboelastometry and FDPs, D-dimer and fibrinogen concentrations

Dogs with intracavitary effusion have coagulative abnormalities indicative of primary fibrinolysis/hyperfibrinolysis. The aim of this case control study was to investigate by rotational thromboelastometry (ROTEM) and standard coagulation tests (fibrin-fibrinogen degradation products, D-dimer and fibrinogen) fibrinolysis in dogs with intracavitary effusions. Thirty-two dogs with intracavitary effusion and 32 control sick dogs without effusion were studied. Frequency of fibrinolysis grade of severity (i.e., hypofibrinolysis/basal fibrinolysis vs increased fibrinolysis vs hyperfibrinolysis) by ROTEM and standard coagulation tests were compared between groups. Pattern of fibrinolysis by ROTEM (i.e., late vs intermediate vs fulminant) and type of fibrinolysis by standard coagulation tests (i.e., hypofibrinolysis/basal fibrinolysis vs primary fibrinolysis vs secondary fibrinolysis vs primary hyperfibrinolysis vs secondary hyperfibrinolysis) were also compared between groups. Dogs with intracavitary effusion had a lesser degree of hypofibrinolysis and basal fibrinolysis and a higher degree of increased fibrinolysis and hyperfibrinolysis compared to controls, both by ROTEM and by standard coagulation tests (P = 0.042 and P = 0.017, respectively). Nevertheless, there was a poor agreement between the two classification schemes (34.4%, K = 0.06, 95% CI = -0.14 ‒ +0.26). Dogs with intracavitary effusion showed, by ROTEM, a lesser degree of hypofibrinolysis and basal fibrinolysis and a higher degree of late, intermediate, and fulminant fibrinolysis compared to controls (P = 0.044). Finally, dogs with intracavitary effusion had, by standard coagulation tests, a higher frequency of primary fibrinolysis and primary hyperfibrinolysis and a lower frequency of secondary fibrinolysis compared to controls. Dogs with intracavitary effusion showed an increased frequency and a different and more severe pattern of fibrinolysis compared to controls.

A review of hyperfibrinolysis in cats and dogs

The fibrinolytic system is activated concurrently with coagulation; it regulates haemostasis and prevents thrombosis by restricting clot formation to the area of vascular injury and dismantling the clot as healing occurs. Dysregulation of the fibrinolytic system, which results in hyperfibrinolysis, may manifest as clinically important haemorrhage. Hyperfibrinolysis occurs in cats and dogs secondary to a variety of congenital and acquired disorders. Acquired disorders associated with hyperfibrinolysis, such as trauma, cavitary effusions, liver disease and Angiostrongylus vasorum infection, are commonly encountered in primary care practice. In addition, delayed haemorrhage reported in greyhounds following trauma and routine surgical procedures has been attributed to a hyperfibrinolytic disorder, although this has yet to be characterised. The diagnosis of hyperfibrinolysis is challenging and, until recently, has relied on techniques that are not readily available outside referral hospitals. With the recent development of point-of-care viscoelastic techniques, assessment of fibrinolysis is now possible in referral practice. This will provide the opportunity to target haemorrhage due to hyperfibrinolysis with antifibrinolytic drugs and thereby reduce associated morbidity and mortality. The fibrinolytic system and the conditions associated with increased fibrinolytic activity in cats and dogs are the focus of this review article. In addition, laboratory and point-of-care techniques for assessing hyperfibrinolysis and antifibrinolytic treatment for patients with haemorrhage are reviewed.