Severity of systemic inflammation is the main predictor of ACLF and bleeding in individuals with acutely decompensated cirrhosis.

BACKGROUND & AIMS: Hypercoagulability and hypofibrinolysis in acutely decompensated cirrhosis (AD) may be implicated in disease progression and haemostatic complications. We conducted a prospective study to: (1) characterise haemostatic alterations in AD; (2) evaluate whether such alterations can predict acute-on-chronic liver failure (ACLF) and bleeding/thrombosis. METHODS: Hospitalised individuals with AD were prospectively recruited and underwent an extensive haemostatic profiling including coagulation factors, thrombomodulin-modified thrombin generation assay with evaluation of endogenous thrombin potential (ETP; marker for plasmatic hypercoagulability), fibrinolytic factors, and plasmin-antiplasmin complex (fibrinolysis activation marker). Inflammation severity was assessed by C-reactive protein (CRP). In part 1 of the study, we compared haemostasis in AD vs. controls (stable decompensated and compensated cirrhosis). In part 2 of the study, we prospectively followed individuals with AD for 1 year and investigated predictors of ACLF and bleeding/thrombosis. RESULTS: A total of 169 individuals with AD were recruited (median model for end-stage liver disease score 20; CLIF-C AD 54). Compared with controls, AD was associated with more pronounced hypercoagulability (ETP: 871 vs. 750 vs. 605 nmol/L per min; p <0.0001), without differences in fibrinolysis activation. During follow-up, 55 individuals developed ACLF. CLIF-C AD, CRP, and Child-Pugh were independently associated with ACLF. A predictive model combining these variables (Padua model) accurately identified individuals at higher risk of ACLF (AUROC 0.857; 95% CI 0.798-0.915; sensitivity 74.5%, specificity 83.3%). Notably, CRP and progression to ACLF, but not baseline coagulopathy, were associated with bleeding (n = 11); CRP and antifibrinolytic factor PAI-1 >50 ng/ml were associated with thrombosis (n = 14). The prognostic value of the Padua model was validated in an independent, bicentric European cohort (N = 301). CONCLUSIONS: Inflammation severity, and not coagulopathy, is the most important predictor of ACLF and bleeding in AD. The Padua model can be used to identify individuals with AD at risk of ACLF. IMPACT AND IMPLICATIONS: A better understanding of haemostasis in individuals with acutely decompensated cirrhosis may help to identify those at higher risk of progression and complications. In this prospective study, we found no significant association between alterations of haemostasis and cirrhosis progression, indicating that the assessment of haemostatic alterations is not useful to identify those at risk. However, we found that C-reactive protein (a simple blood test that reflects severity of inflammation) and severity of chronic liver disease itself (as assessed by specific scores) were associated with cirrhosis progression and development of bleeding complications. Therefore, we developed a simple predictive model - based on C-reactive protein and liver disease scores - that, if validated by independent studies, could be used in clinical practice to assist physicians in identifying individuals with decompensated cirrhosis at higher risk of disease progression and death (i.e. in whom to consider an expedited evaluation for liver transplantation).

Global hemostatic profiling in patients with decompensated cirrhosis and bacterial infections.

Background & Aims: Bacterial infections in cirrhosis are associated with increased bleeding risk. To assess the factors responsible for bleeding tendency in patients with bacterial infections, we conducted a prospective study comparing all 3 aspects of hemostasis (platelets, coagulation, and fibrinolysis) in hospitalized patients with decompensated cirrhosis with vs. without bacterial infections. Methods: Primary hemostasis assessment included whole blood platelet aggregation and von Willebrand factor (VWF). Coagulation assessment included procoagulant factors (fibrinogen, factor II, V, VII, VIII, IX, X, XI, XII, XIII), natural anticoagulants (protein C, protein S, antithrombin) and thrombomodulin-modified thrombin generation test. Fibrinolysis assessment included fibrinolytic factors (plasminogen, t-PA, PAI-1, α2-AP, TAFIa/ai) and plasmin-antiplasmin complex (PAP). Results: Eighty patients with decompensated cirrhosis were included (40 with and 40 without bacterial infections). Severity of cirrhosis and platelet count were comparable between groups. At baseline, patients with cirrhosis and bacterial infections had significantly lower whole blood platelet aggregation, without significant differences in VWF. Regarding coagulation, bacterial infections were associated with reduced procoagulant factors VII and XII, and a significant reduction of all natural anticoagulants. However, thrombomodulin-modified thrombin generation was comparable between the study groups. Finally, although mixed potentially hypo-fibrinolytic (lower plasminogen) and hyper-fibrinolytic (higher t-PA) changes were present in bacterial infections, a comparable level of PAP was detected in both groups. Upon resolution of infection (n = 29/40), platelet aggregation further deteriorated whereas coagulation and fibrinolysis factors returned to levels observed in patients without bacterial infections. Conclusion: In hospitalized patients with decompensated cirrhosis, bacterial infections are associated with reduced whole blood platelet aggregation and a significant decrease of all natural anticoagulants, which may unbalance hemostasis and potentially increase the risk of both bleeding and thrombosis. Lay summary: Bacterial infections are a common issue in hospitalized patients with decompensated cirrhosis (i.e. patients hospitalized due to severe complications of advanced chronic liver disease). Patients with decompensated cirrhosis who acquire infections may be at increased risk of bleeding complications following invasive procedures (that is a procedure in which the body is penetrated or entered, for instance by a needle or a tube). As bleeding complications in decompensated cirrhosis are associated with a high risk of further decompensation and death, there is an urgent need to understand the factors responsible for such increased bleeding tendency. Herein, we investigated the alterations of hemostasis (that is the physiological process responsible for clot formation and stability) in patients with decompensated cirrhosis and bacterial infections. We found that development of bacterial infections in these patients is associated with alterations of hemostasis (particularly of platelets and clotting cascade) that may increase the risk of both bleeding and thrombotic complications.

Assessing Clinically Meaningful Hypercoagulability after COVID-19 Vaccination: A Longitudinal Study.

A large number of daily requests to exclude possible prothrombotic risk factors for coronavirus disease 2019 (COVID-19) vaccines were received. Our aim was to longitudinally evaluate coagulation profiles in a series of healthy subjects who received COVID-19 vaccination and assess hypercoagulability thereafter. Volunteers awaiting a first or second dose of either the ChAdOx1 or BNT162b2 vaccine were enrolled. Venous samples were obtained at baseline (before the vaccine) and longitudinally 3 ± 2 days (T1) and 10 ± 2 days after the vaccine (T2). Global coagulation monitoring was assessed via platelet count, whole blood thromboelastometry and impedance aggregometry, plasma thrombin generation, and anti-platelet factor 4 (PF4)/heparin immunoglobulin G antibodies. One hundred and twenty-two subjects were enrolled (61 [50%] ChAdOx1 and 61 BNT162b2). The ChAdOx1 cohort showed a slight but transient increase in thrombin generation (mainly endogenous thrombin potential [ETP] with thrombomodulin and ETP ratio) at T1, which promptly decreased at T2. In addition, the second dose of either vaccine was associated with increased thrombin peak, ETP with thrombomodulin, and ETP ratio. At baseline, 3.2% of the ChAdOx1 cohort and 1.6% BNT162b2 cohort were positive for PF4/heparin antibodies with a stable titer through T1 and T2. No relevant differences were detected in platelet count and aggregation, or thromboelastometry parameters. No thrombotic or hemorrhagic events occurred. We can confirm that no clinically meaningful hypercoagulability occurred after either vaccine, albeit keeping in mind that thrombin generation may increase in the first days after the second dose of either vaccine and after the first dose of the ChAdOx1 vaccine.

More Pronounced Hypercoagulable State and Hypofibrinolysis in Patients With Cirrhosis With Versus Without HCC.

In patients with cirrhosis, particularly those with hepatocellular carcinoma (HCC), hypercoagulability may be associated with purported increased risks of portal vein thrombosis and cirrhosis progression. In this study, we extensively investigated hemostatic alterations potentially responsible for the thrombotic tendency in HCC, and evaluated whether such alterations were predictive of hepatic decompensation. Patients with cirrhosis at all stages were prospectively recruited and underwent an extensive hemostatic assessment, including all procoagulant factors and inhibitors, thrombin generation with and without thrombomodulin (TG), profibrinolytic and antifibrinolytic factors, and plasmin-antiplasmin complex. In study part 1 (case control), we compared alterations of coagulation and fibrinolysis in patients with cirrhosis with versus without HCC. In study part 2 (prospective), the subgroup of patients with decompensated cirrhosis was followed for development of further decompensation, and predictors of outcome were assessed by multivariate analysis. One-hundred patients were recruited (50 each with and without HCC). Severity of cirrhosis was comparable between groups. Median HCC volume was 9 cm3 (range: 5-16). Compared with controls, patients with HCC demonstrated a significantly more prothrombotic hemostatic profile due to increased TG and reduced activation of fibrinolysis, independent of cirrhosis stage. During a median follow-up of 175 days, 20 patients with decompensated cirrhosis developed further episodes of decompensation that were predicted by low FVII and high plasminogen activator inhibitor-1 levels, independent of Model for End-Stage Liver Disease score. Conclusion: Patients with cirrhosis with HCC have profound hyper-coagulable changes that can account for their increased thrombotic tendency. In contrast, hypercoagulability in patients with decompensated cirrhosis is more likely a consequence of chronic liver disease rather than a driver for cirrhosis progression.

Absence of hypercoagulability after nCoV-19 vaccination: An observational pilot study.

BACKGROUND: It is still unknown whether COVID-19 vaccines induce a prothrombotic state or increase the hypercoagulable condition in subjects with a predisposition to thrombosis. OBJECTIVES: We evaluated the coagulation profile in a series of healthy subjects who received the first dose of the BNT162b2 or the ChAdOx1 vaccines and assessed whether hypercoagulability developed. PATIENTS/METHODS: Volunteers among the staff of the University of Padua or health care professionals in the Padua University Hospital who had received either the ChAdOx1 or BNT162b2 vaccine in the previous 10 ± 2 days were eligible. A cohort of unvaccinated volunteers among family members of the University staff acted as control group. Global coagulation monitoring was assessed by whole blood rotational thromboelastometry, whole blood impedance aggregometry and thrombin generation. Platelet count was also obtained. RESULTS: One hundred and ninety subjects were enrolled: 101 (53.2%) received the ChAdOx1 vaccine and 89 (46.8%) the BNT162b2 vaccine. Twenty-eight non-vaccinated subjects acted as controls. Thromboelastometry parameters were all comparable among groups. Thrombin receptor activating peptide (TRAP)-, ADP- and ASPI-induced platelet aggregation were similar among groups, as well as platelet count. Endogenous thrombin potential (ETP) was comparable among groups. The results were confirmed after controlling for age, gender and hormonal. Considering women taking combined oral contraceptives or thrombophilia carriers, no differences were detected in thromboelastometry or thrombin generation parameters between subjects who received ChAdOx1 vs. BNT162b2 vaccines. CONCLUSIONS: No significant activation of fibrinogen-driven coagulation, plasma thrombin generation or clinically meaningful platelet aggregation after ChAdOx1 or BNT162b2 vaccination was observed.

Acute Kidney Injury in Decompensated Cirrhosis Is Associated With Both Hypo-coagulable and Hyper-coagulable Features.

BACKGROUND AND AIMS: Recent evidence suggests that acute kidney injury (AKI) is the main predictor of postparacentesis bleeding in patients with cirrhosis. To assess the factors responsible for bleeding tendency in AKI, we performed a prospective study comparing all three aspects of hemostasis (platelets, coagulation, and fibrinolysis) in patients with decompensated cirrhosis with and without AKI. APPROACH AND RESULTS: Primary hemostasis assessment included platelet aggregation and secretion (platelet function markers) and von Willebrand factor. Secondary hemostasis assessment included pro-coagulant (factor VIII and factor XIII) and anti-coagulant (protein C, protein S, and antithrombin) factors and thrombin generation. Tertiary hemostasis assessment included fibrinolytic factors and plasmin-antiplasmin complex. Eighty patients with decompensated cirrhosis were recruited (40 each with and without AKI). Severity of cirrhosis and platelet count were comparable between groups. Median serum creatinine was 1.8 mg/dL and 0.8 mg/dL in patients with and without AKI, respectively. At baseline, patients with cirrhosis and AKI had lower platelet aggregation and secretion, indicative of impaired platelet function (increased bleeding tendency), without differences in von Willebrand factor. Regarding coagulation factors, factor VIII was higher, whereas protein C, protein S, and antithrombin were all lower, which, together with increased thrombin generation, indicate hypercoagulability. In contrast, factor XIII was lower in AKI (increased bleeding tendency). Finally, while both hypofibrinolytic and hyperfibrinolytic changes were present in AKI, a higher plasmin-antiplasmin complex indicated a hyperfibrinolytic state. After AKI resolution (n = 23 of 40), platelet function and coagulation improved to levels observed in patients with cirrhosis patients without AKI; however, fibrinolysis remained hyperactivated. CONCLUSIONS: In patients with decompensated cirrhosis, AKI is associated with both hypocoagulable and hypercoagulable features that can potentially increase the risk of both bleeding and thrombosis.

Prophylactic protocol for dental care in ligneous gingivitis due to severe plasminogen deficiency: Case report and review of literature.

INTRODUCTION: Severe plasminogen (PLG) deficiency causes ligneous conjunctivitis, a rare disease characterized by the growth of fibrin-rich pseudomembranes on mucosal surfaces; gums involvement leads to ligneous gingivitis (LG). Specific therapy for LG is not available yet. We report a prophylactic treatment with enoxaparin and fresh frozen plasma (FFP) for invasive dental procedures in a patient with LG, and a review of literature on LG treatment. METHODS: A 43-year-old female with LG was studied. In order to prevent LG recurrence after dental care, FFP before and the day after the procedure, and enoxaparin were administered in addition to proper minimally invasive dentistry techniques and implant surgery. RESULTS: Plasminogen deficiency was confirmed by reduced PLG antigen (25 µg/mL) and activity (20%) levels, and genetic analysis. PLG levels rose to 46% after FFP transfusion and returned to baseline after 48 hours. Minimally invasive dental procedures and implants were performed. Small gingival pseudomembranes developed soon thereafter in some cases but disappeared within a few weeks; no bleeding complications were observed. CONCLUSIONS: In our patient with LG, the adoption of combined haematological and dentistry protocols appeared to be safe and effective in preventing abnormal gingival pseudomembranes growth after dental interventions, maintaining a healthy periodontal condition.

PAI-1 and protein C as early markers of veno-occlusive disease in patients treated for Wilms tumor.

BACKGROUND: Hepatic veno-occlusive (VOD) disease has been described in hematopoietic stem cell transplantation (HSCT), solid tumors, and acute lymphoblastic leukemia. The incidence of VOD in Wilms tumor (WT) ranges from 1.2% to 8%. The diagnosis of VOD is clinical, and there are no validated laboratory biomarkers. PROCEDURE: We prospectively evaluated the specificity and sensitivity of plasminogen-activator inhibitor-1 (PAI-1) and protein C as diagnostic markers of VOD in WT patients. Fifty patients treated from 2008 to 2016 for WT were eligible. VOD was diagnosed according to modified Seattle criteria and retrospectively reclassified according to the recently published criteria for VOD in pediatric HSCT patients. RESULTS: VOD occurred in 6 of 50 patients (12%) after 20 to 97 days from starting chemotherapy. The average duration of VOD was 10 days (range, 4-13 days). PAI-1 levels were elevated in all VOD patients, while a decrease in protein C levels was observed in 33% of patients with VOD. PAI-1 antigen (Ag) values ≥ 26.4 ng/mL demonstrated high sensitivity and specificity for the clinical diagnosis of VOD with sensitivity 100%, specificity 93%; whereas protein C levels below 34.5% had sensitivity 67%, specificity 100%. Both PAI-1 and protein C had an high negative predictive value: PAI-1 Ag 100%; protein C 95%. CONCLUSIONS: PAI-1 Ag and protein C have good sensitivity and specificity for the diagnosis of VOD in WT patients. Their high negative predictive value can be used in the differential diagnosis of liver toxicity, especially in VOD episodes with absent or delayed hyperbilirubinemia.

Venoocclusive disease due to chemotherapy for pediatric acute lymphoblastic leukemia is associated with increased levels of plasminogen-activator inhibitor-1.

We describe three cases of sinusoidal obstruction syndrome/venoocclusive disease (SOS) in pediatric patients with acute lymphoblastic leukemia (ALL). All three episodes occurred during or just after the induction or reinduction phase of treatment based on prednisone/dexamethasone, vincristine, daunorubicin, and pegylated-l-asparaginase. SOS episodes were categorized as mild/moderate and resolved in 7, 10, and 16 days using supportive measures or defibrotide therapy. In all three episodes, the clinical diagnosis of SOS was associated with a significant increase in plasminogen-activator inhibitor-1 (PAI-1) that reduced with patient clinical improvement. PAI-1 warrants study as a diagnostic marker for SOS in ALL.

New insights into sinusoidal obstruction syndrome.

BACKGROUND: Entry criteria included patients who developed sinusoidal obstruction syndrome (SOS) at a single centre from January 2000 to December 2011. Patients who underwent haemopoietic stem cell transplantation or actinomicyn-based chemotherapy for nephroblastoma were selected. The study group comprised five patients with SOS who were compared with a control group of seven patients without SOS. AIM: To study the relationships between endothelial extracellular vesicles (EV) and plasminogen-activator inhibitor type 1(PAI-1) to assess their modification in the early phase of SOS. METHODS: Consecutive blood samples were tested for cell-derived EV, PAI-1 and coagulation parameters. Any statistically significant correlation between all datasets was searched. RESULTS: Antithrombin level and platelet count were statistically significantly reduced in SOS patients, suggesting a consumption status. PAI-1:Ag and PAI-1:act showed an inverse relationship with platelet counts (coef. -0.034, SE = 0.016; P = 0.041 and -0.052, SE = 0.019; P = 0.011 respectively). During follow up, PAI-1:Ag was inversely related to EV CD144+ (coef. -0.261, SE = 0.094; P = 0.007) and antithrombin (coef -0.509, SE = 0.175; P = 0.005). PAI-1:act showed an inverse association with EV CD144+ (coef.-0.251, SE = 0.121; P = 0.043), EV CD31+/CD41+ (coef. -0.004, SE = 0.002; P = 0.026) and antithrombin (coef. -0.470, SE = 0.220; P = 0.038). EV generated by rupture of gap junctions (EV CD144+) were increased in SOS patients and also showed a change over time. CONCLUSION: This study demonstrates the existence of an ongoing procoagulant and hypofibrinolytic status in SOS, indicating a possible role for anticoagulant therapy. Moreover, these findings suggest a role for EV CD 144+, either alone or in combination with PAI-1, as a new biomarker for SOS.

A venous thromboembolism risk assessment model for patients with Cushing's syndrome.

Cushing's syndrome (CS) is associated with an incidence of venous thromboembolism (VTE) about ten times higher than in the normal population. The aim of our study was to develop a model for identifying CS patients at higher risk of VTE. We considered clinical, hormonal, and coagulation data from 176 active CS patients and used a forward stepwise logistic multivariate regression analysis to select the major independent risk factors for thrombosis. The risk of VTE was calculated as a 'CS-VTE score' from the sum of points of present risk factors. VTE developed in 20 patients (4 pulmonary embolism). The group of CS patients with VTE were older (p < 0.001) and had more cardiovascular events (p < 0.05), infections and reduced mobility (both p < 0.001), higher midnight plasma cortisol levels (p < 0.05), and shorter APTT (p < 0.01) than those without. We identified six major independent risk factors for VTE: age ≥69 years and reduced mobility were given two points each, whereas acute severe infections, previous cardiovascular events, midnight plasma cortisol level >3.15 times the normality and shortened APTT were given one point each. A CS-VTE score <2 anticipated no risk of VTE; a CS-VTE score of two mild risk (10 %); a CS-VTE score of three moderate risk (46 %); a CS-VTE score ≥4 high risk (85 %). Considering a score ≥3 as predictive of VTE, 94 % of the patients were correctly classified. A simple score helps stratify the VTE risk in CS patients and identify those who could benefit from thromboprophylaxis.

Activated prothrombin complex concentrate (FEIBA®) for the treatment and prevention of bleeding in patients with acquired haemophilia: A sequential study.

Despite anti-haemorrhagic therapy with proper doses of activated prothrombin complex concentrate (aPCC, Feiba®), patients with acquired haemophilia A (AHA) have a considerable risk of recurrent bleeding complications. Evidence in support of the benefit-to-risk ratio of prevention strategies with the use of lower doses of aPCC following the end of the initial treatment period is scarce and inconclusive. We report our experience in the management of 18 consecutive patients with AHA admitted to two Haemophilia centres in Italy. We managed the first 11 according to current guidelines (e.g., with conventional aPCC doses until bleeding resolution). Then, we decided to prolong the treatment beyond bleeding resolution with lower doses of the same concentrate (short-term prophylaxis) in the 7 additional patients. In these patients, the treatment was continued for as long as the titre of FVIII inhibitor was found to decrease by at least 50% when compared to the baseline one. We observed six relapses of bleeding in patients in whom aPCC was confined to the treatment of the qualifying bleeding episode, and none in patients to whom lower doses were administered until the pre-specified decrease in the titre of FVIII inhibitor was achieved. No patients experienced thrombotic complications during the study period. Prolonging the treatment with lower doses of aPCC beyond the initial phase in patients with AHA in whom the titre of FVIII inhibitor is still high is likely to safely prevent further bleeding complications.

Coronary microvascular dysfunction due to essential thrombocythemia and policythemia vera: the missing piece in the puzzle of their increased cardiovascular risk?

Myeloproliferative neoplasms are most commonly associated with venous thrombosis. Up to 60% of patients experience a thrombotic event in their lifetimes, including stroke or myocardial infarction. It is unclear whether pathogenetic factors linking essential thrombocythemia (ET) and polycythemia vera (PV) to thrombotic complications do play a role in the risk of coronary artery disease (CAD). We aimed to assess coronary flow reserve (CFR) as a marker of coronary microvascular function in asymptomatic patients with ET and PV. Fifty-two patients with ET (M/F 13/39, age 61 ± 7 years) and 22 patients with PV (M/F 13/9, age 60.4 ± 13 years) without clinical evidence of heart disease, and 50 controls matched for age and gender were studied. None had CAD. All control subjects were asymptomatic with no history of heart disease. CFR in the left anterior descending coronary artery was detected by transthoracic Doppler echocardiography, at rest, and during adenosine infusion. In patients with ET and PV, CFR was lower than in controls (2.9 ± 0.94 and 2.2 ± 0.7 vs. 3.8 ± 0.7, P < 0.004 and P < 0.0001 respectively). The prevalence of CFR ≤ 2.5 was higher in patients with ET (20 cases, 38.5%) and PV (15 cases, 68.2%) compared with controls (4.1%) (P < 0.0001). Severe CFR (CFR < 2) impairment was found in eight patients with ET (15.4%), in nine patients with PV (40.9%), and in none of control subjects. The mutation of JAK2 gene was associated with abnormal CFR. Asymptomatic patients with ET and PV have coronary microvascular dysfunction in the absence of clinical conditions suggesting CAD.

Coagulation activation in children with sickle cell disease is associated with cerebral small vessel vasculopathy.

BACKGROUND: Thrombotic complications in Sickle Cell Disease (SCD) arise since infancy, but the role of the coagulation system in children has been poorly explored. To determine its role in the development of clinical complications in childhood we measured coagulation and endothelial parameters in children with SCD at steady state. METHODS: Markers of thrombin generation, fibrin dissolution and endothelial activation were evaluated in 38 children with SS-Sß°, 6 with SC disease and 50 age and blood group matched controls. Coagulation variables were correlated with markers of hemolysis and inflammation, with the presence of cerebral and lung vasculopathy and with the frequency of clinical complications. RESULTS: SS-Sß° patients presented higher levels of factor VIII, von Willebrand factor antigen (VWF:Ag) and collagen binding activity, tissue plasminogen activator antigen (t-PA:Ag), D-dimer, p-selectin, prothrombin fragment1+2 (F1+2) and lower ADAMTS-13:activity/VWF:Ag (p<0.05) compared to controls and SC patients. In SS-Sß° patients coagulation variables correlated positively with markers of inflammation, hemolysis, and negatively with HbF (p<0.05). Patients with cerebral silent infarcts showed significant decrease in t-PA:Ag and ADAMTS-13 Antigen and a tendency toward higher D-dimer, F1+2, TAT compared to patients without them. D-dimer was associated with a six fold increased risk of cerebral silent infarcts. No correlation was found between coagulation activation and large vessel vasculopathy or other clinical events except for decreased t-PA:Ag in patients with tricuspid Rigurgitant Velocity >2.5m/sec. CONCLUSIONS: SS-Sß° disease is associated with extensive activation of the coagulation system at steady state since young age. ADAMTS-13 and t-PA:Ag are involved in the development of cerebral silent infarcts.

Circulating microparticles of glial origin and tissue factor bearing in high-grade glioma: a potential prothrombotic role.

Venous thromboembolism (VTE) may complicate the clinical course of glioblastoma multiforme (GBM). Circulating microparticles (MPs) have been associated with cancer-related VTE. Sixty-one consecutive patients with GBM undergoing gross-total (41) or subtotal (20) surgical resection followed by radio-chemotherapy were prospectively evaluated. MPs numbers according to cellular origin and the procoagulant activity of annexin V positive (AV+) MPs (MP-activity) were measured before surgery and then 1 week and 1, 4, and 7 months after surgery. Glial (GFAP+) and endothelial (CD62E+) derived MPs, AV+ and tissue factor-bearing (TF+) MPs were measured using flow cytometry. Baseline levels of GFAP+/TF-, TF+/GFAP-, and GFAP+/TF+ MPs were significantly higher in GBM patients than in healthy controls, and significantly increased at each time point after surgery; at 7 months, a further significant increase over the level found a week after surgery was only seen in the subtotally resected patients. The number AV+/CD62E- MPs increased in GBM patients and correlated with MP activity. TF+/GFAP- MPs numbers were significantly higher in 11 GBM patients who developed VTE than in those who did not (p 0.04). TF+/GFAP- MPs levels above the 90th percentile (calculated in GBM patients without VTE) were associated with a higher risk of VTE (RR 4.17, 95% CI 1.57-11.03). In conclusion, the numbers of glial-derived and/or TF-bearing MPs were high in GBM patients both before and even more after the neoplasm was treated, especially in patients with subtotal resection likely according to disease progression. A contribution of TF+/GFAP- MPs to the risk of VTE is suggested.

Risk factors, antithrombotic treatment and outcome in retinal vein occlusion: an age-related prospective cohort study.

OBJECTIVES: Antithrombotic treatment for retinal vein occlusion (RVO) is controversial, although RVO has been surmised as a predictor of a subsequent vascular event. We aimed to evaluate risk factors, the effects of antithrombotic therapy and the occurrence of subsequent vascular events in patients with a first episode of RVO, according to age of RVO onset. METHODS: In this prospective cohort study, patients with central (CRVO) and branch RVO (BRVO) confirmed by fluorescein angiography were studied; they were divided according to age. Cardiovascular risk factors and thrombophilia were evaluated. Anticoagulants or aspirin were given for at least 3 months. Patients were followed every 6-12 months and vascular events were recorded. RESULTS: One hundred CRVO and 32 BRVO patients were enrolled. Five of 60 (8.3%) patients <50 yr and 4/72 (5.5%) over 50 yr had a hereditary thrombophilic defect. One or more cardiovascular risk factors were found in 35 (58%) patients of the younger group, and in 66 (91%) of the older group (P < 0.001). Antithrombotic treatment led to both a satisfactory recanalization of occluded veins and visual acuity improvement especially in younger patients. Vascular events occurred in 19 (14%) cases after 4 ± 3.3 yr from RVO, more frequently in older than in younger patients (22% vs. 5%, P = 0.005). CONCLUSIONS: Distribution of cardiovascular, but not of thrombophilic risk factors seems to be influenced by age in RVO patients. Patients with a first RVO, especially those >50 yr, are likely at risk of a subsequent vascular event.

Contribution of fibrinolytic tests to the differential diagnosis of veno-occlusive disease complicating pediatric hematopoietic stem cell transplantation.

BACKGROUND: Veno-occlusive disease (VOD) is a major complication following hematopoietic stem cell transplantation (HSCT). Its diagnosis is based on clinical criteria, which have a limited sensitivity. Increased plasminogen activator inhibitor-1 (PAI-1) levels have been suggested as a marker of VOD. We aimed to prospectively evaluate how the fibrinolytic parameters behaved to discriminate VOD from other liver disorders occurring after HSCT in a pediatric population. PROCEDURES: A total of 195 HSCT were performed on 161 children and VOD complicated 11 cases (6.8%). Alanine aminotransferase, total bilirubin, PAI-1 antigen (PAI-1:Ag) and activity, t-PA antigen, D-dimer, prothrombin time, activated partial thromboplastin time, antithrombin, fibrinogen, and platelet counts were measured in 105 HSCT before and then weekly for 1 month after HSCT. RESULTS: An early, significant increase in the fibrinolytic parameters was seen in patients who developed VOD, even before VOD was diagnosed clinically, by comparison with patients without complications or those with non-VOD liver disorders. The combined increase in bilirubin, D-dimer, and PAI-1:Ag levels beyond the normal range distinguished VOD cases from other liver complications with a high sensitivity and specificity. CONCLUSIONS: Our study demonstrates that fibrinolytic tests can help diagnose VOD after HSCT in the pediatric population.