Design and application of a 23-gene panel by next-generation sequencing for inherited coagulation bleeding disorders.

INTRODUCTION: Molecular testing of Inherited bleeding coagulation disorders (IBCDs) not only offers confirmation of diagnosis but also aids in genetic counselling, prenatal diagnosis and in certain cases genotype-phenotype correlations are important for predicting the clinical course of the disease and to allow tailor-made follow-up of individuals. Until recently, genotyping has been mainly performed by Sanger sequencing, a technique known to be time consuming and expensive. Currently, next-generation sequencing (NGS) offers a new potential approach that enables the simultaneous investigation of multiple genes at manageable cost. AIM: The aim of this study was to design and to analyse the applicability of a 23-gene NGS panel in the molecular diagnosis of patients with IBCDs. METHODS: A custom target enrichment library was designed to capture 31 genes known to be associated with IBCDs. Probes were generated for 296 targets to cover 86.3 kb regions (all exons and flanking regions) of these genes. Twenty patients with an IBCDs phenotype were studied using NGS technology. RESULTS: In all patients, our NGS approach detected causative mutations. Twenty-one pathogenic variants were found; while most of them were missense (18), three deletions were also identified. Six novel mutations affecting F8, FGA, F11, F10 and VWF genes, and 15 previously reported variants were detected. NGS and Sanger sequencing were 100% concordant. CONCLUSION: Our results demonstrate that this approach could be an accurate, reproducible and reliable tool in the rapid genetic diagnosis of IBCDs.

Bioavailability in rats of human recombinant tissue plasminogen activator after subcutaneous and intramuscular injection.

The bioavailability of human recombinant tissue plasminogen activator (rt-PA) in rats was measured after subcutaneous (s.c.) and intramuscular (i.m.) injection. Rt-PA was absorbed after both i.m. and s.c. injection, giving peak plasma concentrations within 30 min and 1 h, respectively, with detectable concentrations up to 6 h. These peak values of bioavailable t-PA were obtained in a functional fibrin plate assay of euglobulin precipitates and expressed as +88% and +243% (for s.c. and i.m. routes respectively) above basal rat fibrinolytic activity. Prior injection of rt-PA, s.c. or i.m., significantly reduced the weights of thrombi induced in the inferior vena cava after injection.

Time course of hemostatic abnormalities in sepsis and its relation to outcome.

OBJECTIVES: To investigate the time course and the relation to prognosis of coagulation and fibrinolytic abnormalities in patients with septic shock. PATIENTS AND METHODS: Forty-eight consecutive patients admitted to the medical ICU with the diagnosis of septic shock (diagnosed by defined criteria) were studied. Mortality was 25 of 48. Mean age was 57 +/- 7.3 years. Blood samples were obtained on days 1, 4, and 7 after hospital admission to measure tissue-type plasminogen activator antigen (t-PA), urokinase-type plasminogen activator (u-PA), plasminogen activator inhibitor antigen (PAI-1), plasminogen, alpha 2-antiplasmin, fibrinogen, antithrombin III, protein C, protein S, thrombin-antithrombin complexes (TAT), D-dimer, and von Willebrand factor-related antigen (vWF:Ag). RESULTS: All patients showed marked abnormalities in both the coagulation and fibrinolytic systems. There were signs of coagulation activation and elevation of both activators and inhibitors of fibrinolysis. Nonsurvivors showed lower levels of protein C and antithrombin III and higher concentration of TAT than survivors. While both t-PA and PAI-1 concentrations were high in survivors and nonsurvivors, only survivors showed a progressive normalization of both parameters during the study period. Low plasminogen levels and plasminogen/alpha 2-antiplasmin ratio were found in both groups, presenting a trend toward normalization only in survivors. The differences reported were not apparent at the time of hospital admission. CONCLUSIONS: Septic shock is characterized by coagulation activation and fibrinolysis activation and inhibition. Nonsurvivors present a particular hemostatic profile characterized by a more marked activation of coagulation and a more intense inhibition of fibrinolysis. None of the abnormalities studied was significantly different between survivors and nonsurvivors at the time of hospital admission. In the presence of fibrin formation, nonsurvivors present a maintained imbalance in the fibrinolytic response determined by higher PAI-1 plasma concentration, probably contributing to their poor outcome.

High plasma levels of plasminogen activator inhibitor 1 (PAI-1) in polycythemia vera and essential thrombocythemia are associated with thrombosis.

We attempted to determine if a hypercoagulability state exists in patients with polycythemia vera (PV) and essential thrombocythemia (ET). We studied the hematocrit level, platelet count, use of any antiaggregant drugs, thrombotic or bleeding accidents and plasma levels of antithrombin III, protein C, total protein S, free protein S, vWF:Ag (Von Willebrand's factor related antigen), thrombin-antithrombin complexes, D-dimer, fibrinolytic activity, tissue plasminogen activator, plasminogen and PAI-1 in 33 patients (19 with ET and 14 with PV). PAI-1 plasma concentration was significantly higher in, both ET and PV patients than in the control group, and were higher in those patients with previous thrombotic episodes than in asymptomatic patients or with previous bleeding episodes. Increasing age was associated to more thrombotic episodes while younger patients presented with more hemorrhagic complications. A linear correlation between platelet count and PAI-1 levels in PV patients (r = 0.44, p < 0.05) and ET patients (r = 0.30, p < 0.05) was found. Fibrinolytic activity in patients with ET was significantly decreased when compared to the control group. A hypofibrinolytic state could be an additional factor which could be used as a predictive index of the thrombotic or bleeding tendency in each patient.

High F1.2 fragment of prothrombin, thrombin-antithrombin III complex (TAT) and soluble fibrin plasma levels demonstrate hypercoagulability induced during loco-regional thrombolytic therapy with rt-PA.

In order to investigate the coagulation and fibrinolysis state in arterial peripheral thrombosis and thrombolysis, we studied 33 consecutive patients (mean age = 65, range: 28-88), 25 males and 8 females diagnosed of acute or subacute lower limb arterial thrombosis, treated with an intrathrombus infusion of rt-PA (0.1 mg/Kg/h) for three hours. Plasma levels of antithrombin III (AT-III), protein C (PC), plasminogen (Pg) and alpha 2-antiplasmin (AP), total and free protein S (PS), thrombin-antithrombin III complex (TAT), F1.2 fragment of prothrombin (F1.2), fibrinogen (Fg), soluble fibrin monomers (FM), tissue-plasminogen activator (t-PA), plasminogen activator inhibitor 1 (PAI-1), total fibrinogen/fibrin degradation products (TDP) and D dimer (DD) were determined prior to the therapeutic regime, at the end of the treatment, and 24 hours later. Levels of AT-III and protein C were somewhat low during the complete study. There was an increase in t-PA, TDP and D Dimer and a decrease of fibrinogen, alpha 2-antiplasmin and plasminogen at 3 hours. An elevation of TAT, fibrin monomers and F1.2 levels was found at three hours. A positive correlation between TAT and F1.2 was observed (r = 0.57, p < 0.05). There was also a positive correlation between soluble fibrin and TAT (r = 0.59, p < 0.05) and with F1.2 (r = 0.56. p < 0.05). These latter facts reflect an hypercoagulable situation induced during loco-regional thrombolytic therapy.

Degree of hypercoagulability and hyperfibrinolysis is related to organ failure and prognosis after burn trauma.

Severely burned patients often present a hypercoagulability situation. However, its magnitude, time course, and relationship with organ failure and outcome remains to be established. Forty-three patients were studied on the first and seventh day after burn for hypercoagulability and fibrinolysis parameters. A hypercoagulability and hyperfibrinolysis state was found the first day after burn demonstrated by high levels of activated factor VII (VIIa, p<0.01), thrombin-antithrombin III complex (TAT, p<0.01), tissue plasminogen activator (t-PA, p<0.001) and D dimer (DD, p<0.01) and low levels of antithrombin III (ATIII, p<0.01), protein C (PC, p<0.01), plasminogen (PG, p<0.001) and alpha2 antiplasmin (AP, p<0.001). A paradoxical coexisting hypofibrinolysis was found as suggested by a low global fibrinolytic activity in the euglobulin plasma fraction fibrin plate assay (FA, p<0.01) and high levels of tissue plasminogen activator inhibitor type 1 (PAI-1, p<0.01). On day 7, a less marked hypercoagulability situation was found, with low ATIII (p<0.01) and PC (p<0.01), persisting the hypofibrinolytic situation observed on the first day. Non-survivors (NS) showed higher levels of VIIa (p<0.01), TAT (p<0.05) and t-PA (p<0.05), and lower levels of ATIII (p<0.05), PC (p<0.05) and AP (p<0.001) than survivors (S) on the first day. Also, there was a positive correlation of Marshall organ failure score with ATIII, (r2=0.49, p<0.001), PC, (r2=0.14, p<0.045) and PG levels, (r2=0.41, p<0.0003). Severely burned patients show a state of transient disseminated intravascular coagulation, related to the development of organ failure and outcome.

Thrombus age and tissue plasminogen activator mediated thrombolysis in rats.

Thrombolytic efficacy is directly related to thrombus age. We used recombinant tissue plasminogen activator (rt-PA), Streptokinase (SK) and Urokinase (UK) on a seven days old inferior vena cava thrombus model. "In vitro" clot lysis assays with fibrinogen-I125 were also evaluated with the same agents at 1, 3 and 7 days. Fibrinogen, D-D dimer and t-PA were measured. Experiments with 40 controls and 27 rt-PA treated animals showed a significant decrease in thrombus weight (8.5 +/- 1.1 mg) vs. (4.2 +/- 0.6 mg) (p less than 0.01). Fibrinogen concentration in rt-PA group decreased significantly (1032 +/- 123 mg/dl) vs. (202 +/- 32 mg/dl) (p less than 0.001). "In vitro" rt-PA showed a marked lytic effect in a wide range (100-4 IU/ml). Fibrin selective agents as rt-PA may be more effective than non selective ones in the treatment of fully developed thrombus.

Fibrinolytic parameters and lipoprotein (a) levels in plasma of patients with coronary artery disease.

Fibrinolysis and lipid disturbances have been considered as independent risk factors for coronary artery disease. Besides this, lipoprotein(a), which is characterized by its homology with plasminogen may interfere with the fibrinolytic function. To evaluate the eventual correlation between fibrinolytic parameters, lipoprotein (a) and other risk factors, 46 patients with coronary artery disease (34 with chronic angina pectoris and 12 with myocardial infarction) were studied. Increased basal values of t-PA antigen (8.2 and 6.6 vs. 4.2 ng/ml) but decreased response after stimulus (2.2 and 1.8 vs. 3.8 ng/ml) and increased levels of lipoprotein(a) (24.7 and 35.9 vs. 10.5 mg/dl) were the most relevant differences between coronary artery disease patients and controls. No correlation between lipoprotein(a) and fibrinolytic parameters was found. Therefore plasma concentration of the main plasma fibrinolytic parameters and lipoprotein(a) seem to be unrelated though the relevance of this interaction at a local level needs to be studied.

Diabetes mellitus as a hypercoagulable state: its relationship with fibrin fragments and vascular damage.

Haemostatic variables were assessed in 43 patients, 28 insulin-dependent and 15 non insulin-dependent. Maximum aggregation by low concentrations of adenosine diphosphate (ADP) or arachidonic acid and elevated plasma concentrations of TxB2, Factor VIII, vWF:Ag, RCoF and fibronectin (Fnct) indicated a hypercoagulable state. The manifestation of vasculopathy was associated with elevated concentrations of RCoF, Fnct, Hbalc, cholesterol and triglycerides, while impaired fibrinolysis was demonstrated by decreased t-PA levels and the absence of crosslinked fibrin degradation products (XL-FDP).

Changes in fibrinolysis in the intensive care patient.

Critically ill patients have been described as having blood coagulation abnormalities that predispose to bleeding and thrombosis. We have studied plasminogen activators, alpha 2-antiplasmin, X-oligomers fibrin fragments, fibronectin, antithrombin III, fibrinogen, platelets, kaolin-cephalin clotting time and prothrombin time on admission to the intensive care unit and sequentially after 24 and 48 hours in 39 adult patients: ARDS (n = 6), trauma (n = 12), sepsis (n = 8) and a miscellanea (n = 13). A decrease in plasminogen activators associated with an increase in X-oligomers, the earliest form of cross linked fibrin degradation products, indicate that fibrin deposition and the consumption of components of fibrinolysis is a widespread condition in the ICU patients. Low fibronectin levels were related to prognosis. These findings suggest that critically ill patients must be evaluated in respect to fibrinolysis and supported when necessary with prophylactic treatment.

Hypofibrinolysis associated with vasculopathy in non insulin dependent diabetes mellitus.

The pathogenesis of diabetic vasculopathy has been related to modifications in hemostasis and fibrinolysis. 50 non insulin dependent diabetes mellitus patients have been studied. Euglobulin clot lysis time, fibrin plate, tissue plasminogen activator (t-PA) antigen, plasminogen activator inhibitor (PAI) activity, Protein C and S, cholesterol, triglycerides and Hb A1c were determined in blood samples. Diabetic patients showed decreased fibrinolytic activity, as measured by ECLT, with clearly increased PAI levels. Fibrinolytic response to venous occlusion was lower than normal. Vascular complications were associated both with an even higher PAI activity and with a decreased fibrinolytic response to venous occlusion. Elevated PAI activity and decreased fibrinolytic response to stimulus may contribute to vascular disease in diabetes.

Oral anticoagulant treatment: risk factors involved in 500 intracranial hemorrhages.

Intracranial bleeding is the most severe complication caused by anticoagulant or antiplatelet treatment. The increasing use of this therapy, especially in older people, makes the balance between clinical benefit and bleeding risk an important consideration. A retrospective study of all consecutive 500 intracranial hemorrhages in the West Valladolid area, approximately 220,000 people, during the period 1998 to 2004, was performed. In relation to mortality, predisposing conditions were included, such as age, antithrombotic treatment, arterial hypertension, cancer, blood diseases, vascular malformations, and traumatisms. The incidence of intracranial hemorrhage was 310 per 100,000 per year with a mortality of 30%. Higher mortality was found in antiplatelet-treated patients (44.9%) than in anticoagulated patients (31.1%). This may be related to a different mean age of 78 vs. 71 years. Arterial hypertension was the most frequent risk factor (45.1% in nontreated patients, 60% anticoagulated, and 75.5% antiplatelet). The relative risk of intracranial bleeding in anticoagulated patients was 11.2 (p < 0.001) with an incidence of 0.03% and a median of 14 months since treatment began. The median INR was 3.3. In 40% of the patients the previous five controls were in range. Strict consideration of indications criteria joined to a better control of risk factors may avoid intracranial bleeding episodes.

[Purification of fibronectin using gelatin derivatives]. / Purificación de fibronectina mediante derivados de gelatina.

This work compares two distinct methods, column and batch, for the purification of fibronectin, from different plasma fractions, using gelatin and one of its derivates (Hemoce, Behring). The yields of both techniques at quantitative as well as qualitative levels (levels of immunologically active fibronectin), are evaluated. The data indicate that better conservation of immunological immunological characteristics is obtained with the use of gelatin derivatives (Hemoce). The plasma fraction does not have significant influence on the process yields.

[Current status of thrombolysis. The need for coadjuvant antithrombotic therapy]. / Estado actual de la trombolisis. Necesidad de la terapéutica antitrombótica coadyuvante.

Thrombolytic therapy yields a 80% repermeabilitation in the acute myocardium infarct if applied soon. In other thrombotic sites such as deep venous thrombosis, pulmonary thromboembolism and peripheral arterial thrombosis, with no large cooperative randomized clinical trials, its usefulness is clear, tough selectively. The high rethrombosis frequency is the major drawback of this therapy. The concomitant use of an anti-thrombotic and/or anti-aggregant agent, even tough the possible higher risks of hemorrhages, seems a key element to improve the results obtained with thrombolysis.

[Familial thrombophilia due to resistance to activated protein C]. / Trombofilia familar debida a resistencia a la proteína C activada.

Resistance to activated protein C (RAPC) has been described recently as a cause of trombophilia; this may justify up to 50% of thromboembolic disease without predisposing cause in patients under 45 years. A 29 years-old male with a previous deep venous thrombosis (DVT) in the lower left limb three years earlier, developed a DVT in the right lower limb after a trauma of the knee that required immobilization, was associated to pulmonary thromboembolism diagnosed by gammagraphic methods. The phlebographic study showed femoro-iliaco-caval venous thrombosis. The proband's father and a younger brother had a previous history of thrombotic episodes. The following tests, were performed in the proband and relatives: prothrombin time, aPTT, thrombin time, fibrinogen, (Von Clauss), antithrombin III (chromogenic), protein C and protein S (coagulometry and ELISA), plasminogen (chromogenic) and lupus anticoagulant (ITT, dRVVT, aCL). RAPC was evaluated in two different samples. The proband study was performed under oral anticoagulation treatment (OAT). Control groups were: 21 blood donors and 12 OAT patients. The results showed a decreased response to APC in the proband (ratio 1.5) and relatives: father (1.4), brothers (1.5 and 1.5), while the mother was within the normal range (> or = 2). In normal controls and OAT patients the ratio was over 2. No other abnormalities were detected in the assays performed. It is concluded that RAPC is the cause of this familial trombophilia. RAPC should be included in the evaluation study of trombophilia.

[Thrombolytic agents: efficacy in relation to evolution time and dose]. / Agentes trombolíticos: efectividad en relación con el tiempo de evolución y dosis.

"In vitro" efficacy of urokinase (UK), streptokinase (SK) and tissue-type plasminogen activator (t-PA) was studied. Lytic action was measured by dry clot weight, 125I counts released from previously incorporated 125I-fibrinogen and fibrin fragment quantification at 1, 3 and 7 days using different doses. t-PA doses between 100 and 0.8 IU/ml were efficient. t-PA (40 IU/ml), SK (200 IU/ml) and UK (200 IU/ml) showed an equivalent activity in 1, 3 and 7 day-old clots. Fibrin fragment (D-D dimer) production was highest when t-PA and UK were used. "In vitro" lytic capacity up to 7 days after clot formation has been proved with the different fibrinolytic agents.

High plasma urokinase-type plasminogen activator levels are present in patients with acute nonlymphoblastic leukemia.

An exaggerated hemorrhagic syndrome is a characteristic in acute non-lymphoblastic leukemia (ANLL) and it determines the patient's outcome. Disseminated intravascular coagulation as a result of a procoagulant factor release and primary hyperfibrinolysis due to plasminogen activators also released by leukemic cells have been implicated in the development of this syndrome. The aim of this work was to evaluate urokinase-type plasminogen activator (u-PA) and related parameters of the fibrinolytic system in 14 ANLL patients. Our results showed an increased u-PA concentration in ANLL patients compared to controls [2.63 (1.61-4.62) vs. 0.95 (0.77-1.48) ng/ml, p < 0.01]. u-PA levels correlated positively with tissue-type plasminogen activator. The relevance of the enhancement of u-PA in this clinical setting was supported by the fact that it was the only analytical parameter positively correlated with patient mortality (p < 0.05). Though u-PA levels do not seem to be the determining factor in the development of the hemorrhagic syndrome of ANLL patients, a contributory role of this plasminogen activator is suggested from our results.

Efficacy of D-dimer and total fibrin degradation products evaluation in suspected pulmonary embolism.

Three different assays for fibrin/fibrinogen degradation products (FDP) were evaluated in patients with suspected pulmonary embolism (PE) as rapid screening tests with the aim of evaluating whether they could be used either as a substitute of ventilation/perfusion lung scanning or to supplement scintigraphy in patients in whom the scan was inconclusive (low or intermediate probability). D-Dimer by enzyme-linked immunosorbent assay (ELISA) and latex and total FDP by ELISA were measured prospectively in 85 consecutive patients with suspected PE. With a cutoff of 500 ng/ml, D-dimer by ELISA presented a 96% sensitivity and a 42% specificity, with positive and negative predictive values of 49 and 96%, respectively. D-Dimer by latex, also with a cutoff of 500 ng/ml showed a 93% sensitivity and 29% specificity, with positive and negative predictive values of 43 and 89%. For total FDP, with a cutoff of 900 ng/ml, the sensitivity and specificity were 96 and 26% respectively, with positive and negative predictive values of 42 and 93%. A normal assay may have reduced the necessity of a ventilation/perfusion only in 28% patients with D-dimer ELISA, 21% with D-dimer latex and 17% with total FDP ELISA and with a possible error of 4, 11 and 7%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hemostasis profiles in thrombotic disease]. / Perfiles de hemostasia en la enfermedad trombótica.

It is well known that in thrombotic disease the alteration of biological factors such as antithrombin III, protein C, and protein S deficiency, and congenital disfibrinogenimias and displasminogenemias are determining factors being the acquired alterations not so well known. With this in mind was studied 85 patients with arterial thrombosis and 196 with venous thrombosis, who were again divided into three groups: unique or of repetition, less or more than 35 years and with or without immediate apparent cause. The general clinical-biological profile in patients with thrombosis in whom a congenital deficit is not detected, can help establish prognosis and treatment in these patients. In our patients, together with the importance of factors such as obesity, hyperlipemia, and tabaquism, an increase in fibrinogen (Fg), antigenic Factor VII (vWF:Ag), total protein S is observed as well as a decrease in total fibrinolytic activity related to an increase in the inhibitor of the plasminogen tissue activator (PTA).