Thrombin Generation Markers as Predictors of Cancer-Associated Venous Thromboembolism: A Systematic Review.

Venous thromboembolism (VTE) is a main contributor to morbidity and mortality in cancer patients. Biomarkers with the potential to predict cancer-associated VTE are continually sought. Of these, markers of thrombin generation present a likely option. The present systematic review examines the ability of three widely used biomarkers of thrombin generation: prothrombin fragment 1.2 (F1.2), thrombin-antithrombin complex (TAT), and ex vivo thrombin generation, to predict VTE in both solid and hematologic adult cancer patients. Relevant studies were identified in the PubMed and Embase databases, and the review conformed to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Each study was evaluated using the quality assessment tool from the National Heart, Lung, and Blood Institute. The review protocol was published on PROSPERO with identifier CRD42022362339. In total, 24 papers were included in the review: 11 reporting data on F1.2, 9 on TAT, and 12 on ex vivo thrombin generation. The quality ratings of the included studies varied from good (n = 13), fair (n = 8), to poor (n = 3) with a high heterogenicity. However, F1.2, TAT complex, and ex vivo thrombin generation were all found to be associated with the development of VTE. This association was most pronounced for F1.2. Furthermore, the determination of F1.2 was able to improve the precision of several established risk assessment scores. In conclusion, markers of thrombin generation were found to be elevated in cancer patients with VTE, and particularly, F1.2 was found to be a promising predictor of cancer-associated VTE.

Serum glial fibrillary acidic protein (GFAP) predicts outcome after intracerebral and subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Intracerebral and subarachnoid hemorrhage are critical conditions with a high mortality, and the outcome for the individual patient is notoriously difficult to predict. Biomarkers that reflect disease severity and predict outcome are therefore warranted. METHODS: Blood samples from 40 patients with intracerebral, 46 patients with subarachnoid hemorrhage, and 70 healthy individuals were collected. Levels of glial fibrillary acidic protein (GFAP) and neuroglobin were measured by ultra-sensitive single molecule array and enzyme-linked immunosorbent assay, respectively. Clinical information including mortality and functional outcome was recorded. RESULTS: Blood levels of GFAP and neuroglobin in intracerebral and subarachnoid hemorrhage patients were significantly elevated when compared to healthy individuals (all p < 0.0001). GFAP levels were significantly higher in patients dying or with poor functional outcome than in healthy individuals (all p ≤ 0.01). GFAP levels separated survivors from non-survivors with an area under receiver operating characteristics (AUROC) = 0.78 (confidence interval (CI) 0.59-0.98) for intracerebral hemorrhage and 0.82 (CI 0.69-0.94) for subarachnoid hemorrhage patients. The Akaike and Bayesian information criteria (AIC/BIC) for mortality/poor outcome prediction improved when combining GFAP levels with hematoma volume (p = 0.04/p < 0.01), National Institutes of Health Stroke Scale (NIHSS) (p = 0.09/p < 0.01), Hunt-Hess (p < 0.05/p = 0.21), or Fischer score (p < 0.05/p = 0.02). CONCLUSIONS: Elevated GFAP levels at admission to hospital predicted mortality and poor outcome in our cohort of intracerebral and subarachnoid hemorrhage patients. Neuroglobin levels did not provide additional information. Combining GFAP measurements with clinical disease severity scores increased outcome prediction precision. This may suggest that GFAP measurement could improve prognostication in patients with intracerebral or subarachnoid hemorrhage. REGISTRATION: This sub-trial was not registered.

Haemolysis in prehospital blood samples.

The increasing use of Point Of Care Testing (POCT) in the prehospital setting demands a high and consistent quality of blood samples. We have investigated the degree of haemolysis in 779 prehospital blood samples and found a significant increase in haemolysis compared to intrahospital samples. The degree of haemolysis was within acceptable limits for current analyses. However, haemolysis should be taken into account when implementing future analyses in the prehospital field.

Ex vivo effect of hemostatic therapy in subarachnoid and intracerebral hemorrhage.

BACKGROUND: Rebleeding and hematoma growth are serious complications in subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH). As treatment options are sparse, a mechanistic approach may reveal new therapeutic targets. AIM: Firstly, to evaluate hemostasis using a sensitive low tissue factor thromboelastometry (ROTEM®) assay in patients with SAH or ICH and compare them with healthy controls. Secondly, to investigate the ex vivo effect of hemostatic or antifibrinolytic medications in blood from patients with SAH or ICH. METHODS: Blood was drawn on admission to hospital in patients with SAH (n = 39) or ICH (n = 35). We included 41 sex and age matched healthy controls for comparison. A low tissue factor (diluted 1:100,000) ROTEM® assay was run in patients and healthy controls. In parallel, coagulation factor XIII, fibrinogen concentrate, prothrombin complex concentrate, and recombinant soluble thrombomodulin were added in concentrations equivalent to doses used in clinical practice. RESULTS: Patients with SAH or ICH demonstrated a hypercoagulable profile indicated by significantly shorter clotting time, faster maximum velocity, shorter time to maximum velocity, and higher maximum clot firmness than healthy controls (all p-values <.0001). Ex vivo addition of coagulation factor XIII, fibrinogen concentrate, prothrombin complex concentrate, and recombinant soluble thrombomodulin, respectively, did not improve the hemostatic potential in patients with SAH or ICH. CONCLUSION: Patients with SAH or ICH demonstrated a hypercoagulable state in the systemic circulation as evaluated by a sensitive low tissue factor assay. Ex vivo addition of hemostatic medication did not further improve coagulation.

Plasma neurofilament light chain is associated with mortality after spontaneous intracerebral hemorrhage.

Background Neurofilament light chain (NfL) is a neuron-specific biomarker with prognostic ability in several types of central nervous system injuries. This study investigates if plasma NfL (pNfL) is elevated early after spontaneous intracerebral hemorrhage (ICH) and whether such elevation reflects disease severity and day-30 outcome. Methods pNfL was quantified by single molecule array analysis in 103 reference subjects (RS) and in samples from 37 patients with ICH obtained on admission to hospital and at 24-h follow-up. The primary outcome was day-30 mortality. Clinical status on admission was evaluated by standardized scoring systems. Results Median pNfL among RS was 9.6 (interquartile range [IQR] 6.2) pg/mL. Upon admission, ICH patients had pNfL of 19.8 (IQR 30.7) pg/mL increasing to 35.9 (IQR 44.5) pg/mL at 24 h (all, p < 0.001). On admission, pNfL was higher among ICH non-survivors than survivors (119.2 [IQR 152.6] pg/mL vs. 15.7 [IQR 19.6] pg/mL, p < 0.01) and this difference was observed also on 24 h follow-up (195.1 [IQR 73.9] pg/mL vs. 31.3 [IQR 27.8] pg/mL, p < 0.01). The area under the receiver operating characteristic curve (ROC AUC) for discrimination of day-30 mortality was significant on admission (AUC = 0.83, 95% confidence interval [CI]: 0.56-1.0) and increased on 24-h follow-up (AUC = 0.93, 95% CI: 0.84-1.0). The odds ratio (OR) for death, by each quartile increase in pNfL was significant both on admission (OR = 4.52, 95% CI: 1.32-15.48) and after 24-h follow-up (OR = 9.52, 95% CI: 1.26-71.74). Conclusions PNfL is associated with day-30 mortality after spontaneous ICH when early after the ictus.

Plasma Neurofilament Light Chain Is Associated with Poor Functional Outcome and Mortality Rate After Spontaneous Subarachnoid Hemorrhage.

The initial clinical status after subarachnoid hemorrhage (SAH) is an important outcome predictor, but the mechanisms behind the early brain injury (EBI) remains incompletely understood. Elevated neurofilament levels in the cerebrospinal fluid at protracted stages after SAH are associated with poor outcome, but the potential association between plasma neurofilament (pNfL) levels during EBI, disease severity on admission, and poor outcome remains unaddressed. Plasma NfL (pNfL) was measured by single molecule array in 44 SAH patients on admission and 24 h after ictus, as well as in 44 controls. Disease severity on admission was assessed by validated scoring systems, and day 30 modified Rankin Scale (mRS) score was registered. Admission levels of pNfL correlated with clinical disease severity scores (rho = 0.43, p < 0.01 and rho = 0.48, p < 0.001) as well as day 30 mRS score (rho = 0.53, p < 0.001). Each quartile increase in pNfL was independently associated with poor functional status (mRS > 4) [odds ratio = 1.98, 95% confidence interval (CI): 1.01-3.88, p = 0.05]. Non-survivors had higher pNfL than survivors; on admission [17.6 pg/mL (IQR 11.4) vs. 8.4 pg/mL (IQR: 8.9), p < 0.01] and 24 h after ictus [29.9 pg/mL (IQR 90.4) vs 7.8 pg/mL (IQR 26.9), p = 0.01]. Each quartile increase in pNfL was independently associated with reduced survival rate [log-rank = 0.02, hazard ratio = 2.29 (95% CI): 1.15-4.57), p = 0.02]. PNfL levels are associated with disease severity during the EBI phase of SAH. Higher pNfL levels during EBI are associated with poor functional outcome on day 30 after ictus and increased mortality rate.

No hyperfibrinolysis following subarachnoid or intracerebral haemorrhage: a prospective cohort study.

: Changes in fibrinolysis following subarachnoid haemorrhage (SAH) and intracerebral haemorrhage (ICH) are sparsely investigated. To investigate fibrinolysis in the acute phase in SAH and ICH patients compared with healthy individuals, fibrinolysis after 24 h in ICH patients and the in-vivo effect of tranexamic acid (TXA) on fibrinolysis in SAH patients. Further, ex-vivo studies were performed by addition of several haemostatic agents to blood samples obtained at admission. Blood was sampled from 46 SAH and 41 ICH patients upon admission. In ICH patients, a second blood sample was obtained 24 h after symptom onset, and in SAH patients after TXA treatment. A sex-matched healthy control group was used for comparison. Fibrinolysis and clot stability were assessed by a dynamic fibrin clot lysis assay, and measurements of plasminogen activator inhibitor I, tissue plasminogen activator and coagulation factor XIII were performed. On admission, no difference in lysis time was found in SAH or ICH patients compared with healthy controls (all P values >0.15). For SAH and ICH patients, median plasminogen activator inhibitor I, tissue plasminogen activator and factor XIII levels were within the reference intervals. In ICH patients, lysis time remained within 24 h after symptom onset (P = 0.63). In SAH patients, the clot lysis curve showed a complete block of fibrinolysis after TXA administration. Ex-vivo addition of solulin and prothrombin complex concentrate reduced fibrinolysis (P < 0.001). SAH and ICH patients showed no hyperfibrinolysis on admission. Fibrinolysis remained normal in ICH patients, and TXA treatment obliterated fibrinolysis in SAH patients.

Thromboelastometry Shows Early Hypercoagulation in Patients with Spontaneous Subarachnoid Hemorrhage.

BACKGROUND: The ability to achieve hemostasis after spontaneous subarachnoid hemorrhage (SAH) plays a pivotal role in outcome. Changes in coagulation in the early hours after SAH have been only sparsely investigated. OBJECTIVE: To investigate changes in coagulation after SAH and illuminate underlying mechanisms. METHODS: We enrolled 46 patients with spontaneous aneurysmal SAH. Blood samples were collected at admission and 24 hours after symptom onset. Thromboelastometry (ROTEM) was performed using the standard assays EXTEM, INTEM, and FIBTEM. Platelet maximum clot elasticity was calculated based on ROTEM results. Thrombin generation, levels of thrombin-antithrombin complex, fibrinogen, and coagulation factor XIII were measured. All data were compared with a gender-matched healthy control group. RESULTS: At admission (median, 3 hours 39 minutes from symptom onset), maximum clot firmness (EXTEM, P < 0.0001; INTEM, P = 0.08; FIBTEM, P < 0.0001) and platelet maximum clot elasticity (P < 0.0001) were higher in patients with SAH than in healthy controls. Thrombin generation showed higher, although nonsignificant, endogenous thrombin potential in patients with SAH than in healthy controls (P = 0.06), and thrombin-antithrombin complex levels were above the reference interval. Median fibrinogen and coagulation factor XIII levels were both within the reference parameters and remained increased 24 hours after symptom onset, whereas endogenous thrombin potential (P = 0.01) and thrombin-antithrombin complex levels decreased (P < 0.0001). CONCLUSIONS: Patients with SAH were in a hypercoagulable state at admission and remained so 24 hours after SAH. Increased clot firmness could be caused by increased platelet function, because platelet maximum clot elasticity was increased despite normal fibrinogen and coagulation factor XIII levels.

Coagulation Profile after Spontaneous Intracerebral Hemorrhage: A Cohort Study.

BACKGROUND: Intracerebral hemorrhage (ICH) causes death or disability and the incidence increases with age. Knowledge of acute hemostatic function in patients with ICH without anticoagulant and antiplatelet therapy is sparse. Increased knowledge of the coagulation profile in the acute phase of ICH could improve acute treatment and recovery. We investigated coagulation at admission and changes in coagulation during the first 24hours after symptom onset. METHODS: Enrolled were 41 ICH patients without anticoagulant or antiplatelet therapy admitted to Aarhus University Hospital, Denmark. Blood samples were collected at admission, 6, and 24hours after symptom onset. Thromboelastometry (ROTEM), thrombin generation, and thrombin-antithrombin (TAT) complex were analyzed. Clinical outcome was evaluated using the National Institute of Health Stroke Scale, the Modified Rankin Score, and mortality. RESULTS: At admission, compared with healthy individuals, ICH patients had increased maximum clot firmness (EXTEM P < .0001; INTEM P < .0001; FIBTEM P < .0001), increased platelet maximum clot elasticity (P < .0001) in ROTEM, higher peak thrombin (P < .0001) and endogenous thrombin potential (P = .01) in thrombin generation, and elevated TAT complex levels. During 24hours after significantly, while thrombin generation showed decreased peak thrombin (P < .0001) and endogenous thrombin potential (P < .0001). Coagulation test results did not differ between patients when stratified according to clinical outcome. CONCLUSIONS: ICH patients without anticoagulant or antiplatelet therapy demonstrated activated coagulation at admission and within 24hours after symptom onset.

Polarization of membrane associated proteins in the choroid plexus epithelium from normal and slc4a10 knockout mice.

The choroid plexus epithelium (CPE) has served as a model-epithelium for cell polarization and transport studies and plays a crucial role for cerebrospinal fluid (CSF) production. The normal luminal membrane expression of Na(+),K(+)-ATPase, aquaporin-1 and Na(+)/H(+) exchanger 1 in the choroid plexus is severely affected by deletion of the slc4a10 gene that encodes the bicarbonate transporting protein Ncbe/NBCn2. The causes for these deviations from normal epithelial polarization and redistribution following specific gene knockout are unknown, but may be significant for basic epithelial cell biology. Therefore, a more comprehensive analysis of cell polarization in the choroid plexus is warranted. We find that the cytoskeleton in the choroid plexus contains αI-, αII-, ßI-, and ßII-spectrin isoforms along with the anchoring protein ankyrin-3, most of which are mainly localized in the luminal membrane domain. Furthermore, we find α-adducin localized near the plasma membranes globally, but with only faint expression in the luminal membrane domain. In slc4a10 knockout mice, the abundance of ß1 Na(+),K(+)-ATPase subunits in the luminal membrane is markedly reduced. Anion exchanger 2 abundance is increased in slc4a10 knockout and its anchor protein, α-adducin is almost exclusively found near the basolateral domain. The αI- and ßI-spectrin abundances are also decreased in the slc4a10 knockout, where the basolateral domain expression of αI-spectrin is exchanged for a strictly luminal domain localization. E-cadherin expression is unchanged in the slc4a10 knockout, while small decreases in abundance are observed for its probable adaptor proteins, the catenins. Interestingly, the abundance of the tight junction protein claudin-2 is significantly reduced in the slc4a10 knockouts, which may critically affect paracellular transport in this epithelium. The observations allow the generation of new hypotheses on basic cell biological paradigms that can be tested experimentally in future studies.