Faktor-VII-Mangel und Varianten

Die kongenitalen und erworbenen Faktor-VII-Mangelzustände und Varianten sind jetzt gut bekannte klinische Einheiten. Der kongenitale Faktor-VII-Mangel ist eine autosomal inkomplett rezessiv vererbte Erkrankung. Er ist charakterisiert durch den Mangel an Faktor-VII-Aktivität und Faktor-VII-Antigen (echter Mangel) oder durch den Mangel an Aktivität und verschiedene Mengen von Antigen (Variante oder abnorme Formen). Außerdem zeigen einige Patienten mit normalem Faktor-VII-Antigen eine unterschiedliche Reaktivität mit verschiedenen Gewebethrombo-plastinen. Faktor VII Padua z.B. zeigt eine normale Reaktivität mit Ochsenhirn-Thromboplastin und eine niedrige Aktivität mit Kaninchenhirn-Thromboplastin. Die Klassifizierung des kongenitalen Faktor-VII-Defektes muß daher beide Fakten berücksichtigen, nämlich das Fehlen oder die Gegenwart von Antigen (VII_, VIIred und VII+) und die Reaktivität mit Gewebethromboplastin verschiedener Herkunft. Die Blutungsmanifestationen sind variabel und nicht spezifisch. In schweren Fällen sind Hämarthro-sen beschrieben worden. Bei manchen Patienten ist die Blutungsneigung mild. Gelegentlich sind auch thrombo-embolische Manifestationen beschrieben worden, was bedeutet, daß ein Mangel an Faktor VII kein Schutz gegen thrombotische Phänomene ist. Die Diagnose des Faktor-VII-Defekts basiert auf dem Nachweis einer verlängerten Prothrombinzeit gemeinsam mit einer normalen partiellen Throm-boplastinzeit und Stypven-Cephalin-Gerinnungszeit. Der Faktor-VII-Aktivitätstest kann unterschiedlich stark vermindert sein und Gewebethrombo-plastine verschiedener Herkunft sollten in diesem Test verwendet werden. Bei Fällen mit klassischem Mangel wird keine sichere Diskrepanz bei Verwendung verschiedener Thromboplastine beobachtet. Ein immunologischer Test ist notwendig, wenn eine Diskrepanz von mehr als 15% bei einem Faktor-VII-Aktivitätsspiegel von 40-60% der Norm erhalten wird und die Patienten vollständig asymptomatisch sind. Die Substitutionstherapie beruht auf der Verabreichung von Plasma, Prothrombinkomplex-Konzentraten und Faktor-VII-Kon-zentraten. Eine große Häufigkeit von Virushepatitis scheint die Verwendung der Faktor-VII-Konzentrate einzuschränken. Erworbene Faktor-VII-Defekte sind mit dem Mangel an anderen Faktoren des Prothrombinkom-plexes verbunden.

Budd-Chiari syndrome during nephrotic relapse in a patient with resistance to activated protein C clotting inhibitor

It has long been known that patients with nephrotic syndrome have a hypercoagulable state, which explains the association between nephrotic syndrome, renal vein thrombosis, and thromboembolism. However, the Budd-Chiari syndrome has never been reported in nephrotic patients. This is the first report of such an association that, most likely, depended on a primary resistance to activated protein C.

Demonstration that venous occlusion fails to release von Willebrand factor multimers

The acute simultaneous release of tissue plasminogen activator (t-PA) and von Willebrand factor (vWF) from endothelial cells in response to a variety of agonists including thrombin, DDAVP, histamine and adrenalin has been described. In the present study we investigated the effect of venous occlusion on the circulating levels of t-PA and vWF, as well as the molecular organization of vWF in 20 normal subjects. After occlusion a significant increase in plasma t-PA levels was observed even after the values were corrected for haemoconcentration. Venous occlusion also enhanced plasma vWF values, but the increase was abolished when the correction for haemoconcentration was introduced. Following venous occlusion, no circulating abnormally large vWF multimers were detected in the subjects studied. These forms are normally not present in the circulation and are released from endothelial cells through the regulated vWF pathway; their absence therefore seems to demonstrate that this pathway is not activated after venous occlusion. Since occlusion does not enhance vWF synthesis, the increase in vWF observed in the subjects investigated may be fully attributed to haemoconcentration.

Impaired release of tissue plasminogen activator (t-PA) following DDAVP infusion in von Willebrand's disease with low platelet von Willebrand factor content

Tissue plasminogen activator (t-PA) and von Willebrand factor (vWF) are both released by vascular endothelial cells after the infusion of DDAVP. Such release has not been observed in patients with severe von Willebrand's disease (vWD). In the present work we demonstrate that the degree of simultaneous DDAVP-induced release of t-PA and vWF, in patients with vWD, is strictly related to the platelet vWF content. Twelve patients with type I, and three patients with type III vWD were studied. The type I vWD group included three patients with reduced platelet vWF content (platelet-low) and nine patients with normal levels (platelet-normal). In all patients studied the plasma t-PA levels were within the normal range. No significant change in either t-PA or vWF was observed after DDAVP in the patients with undetectable levels of platelet vWF (type III vWD). A mild increase was found in those patients with type I platelet-low, while in type I platelet-normal vWD the response was similar to that observed in normal subjects. The release of the two molecules appeared, therefore, to be linked to platelet vWF content and the rates of increase in both t-PA and vWF were similar in each group of patients studied. Since platelets are regarded as a tissue compartment of vWF our findings seem to suggest that the presence of vWF and its release from endothelial cells is required for a normal concomitant release of t-PA. In contrast, post-DDAVP release of vWF seems to be independent from that of t-PA since it was normal in a patient with congenital deficiency of t-PA release.

Cardiovascular and hormonal responses to DDAVP before and after beta-blockade in patients with mild essential hypertension

The aim of this study was to assess the cardiovascular and hormonal responses to 1-desamino-8,D-arginine vasopressin (DDAVP) in hypertensive patients before and after non-selective beta-blockade. We infused DDAVP at 400 ng/kg body weight for 10 min in nine subjects with mild essential hypertension before and 14 days after administration of nadolol at 80 mg/day. Blood pressure and heart rate were recorded, and blood was drawn at 0, 30 and 60 min for measurement of plasma renin activity, aldosterone, cortisol, noradrenaline, adrenaline and dopamine. Before the administration of nadolol, DDAVP induced a significant decrease in blood pressure, and significant increases in the heart rate, plasma renin activity, cortisol and noradrenaline; there were no changes in adrenaline or dopamine. After the administration of nadolol, baseline noradrenaline was significantly increased, while cortisol, adrenaline and dopamine remained unchanged. A second infusion of DDAVP did not significantly alter blood pressure, [corrected] heart rate, noradrenaline, adrenaline or dopamine, but plasma renin activity, aldosterone and cortisol still showed a significant increase. The blunted hypotensive effect of DDAVP after the administration of nadolol may be aspecific, due to lower basal blood pressure levels, or may indicate a mechanism of action common to both drugs. A similar post-DDAVP increase before and after beta-blockade suggests that the drug has a direct effect on the renin-secretory apparatus. An indirect effect, mediated by changes in intrarenal haemodynamics or by other factors with renin-stimulating activity, e.g. tissue plasminogen activator, can also be hypothesized.

Effect of captopril on inactive renin and contact phase of coagulation system

It has been suggested that a Factor XII-plasma Prekallikrein dependent pathway might play an important role in the activation of inactive renin. Since Captopril has the potential to affect the kinin-kallikrein system, we have studied in a group of 16 patients with essential hypertension its acute effect both on the levels of active, inactive and total renin, and on the contact phase of the coagulation system. Our results show that a single dose of Captopril (25 mg) induces a rapid and persistent increase of active and total renin, while inactive renin tends to decrease. Together with blood pressure, plasma Prekallikrein(PK), Factor XII(FXII) and Factor XI(FXI) concomitantly decrease, although not significantly, and their values seem to return to basal levels soonafter. However, no correlation was found at any time between the levels of any of these coagulation factors, including PK, and those of inactive, active or the ratio inactive/total renin. In spite of that, it is still possible that an activation of PK, which is likely to occur under Captopril administration, may affect at least the conversion of vessel-bound prorenin rather than the circulating form.

An immunological study of prothrombin in liver cirrhosis

Prothrombin was assayed in 24 patients with liver cirrhosis both as activity and as antigen. Prothrombin was found to be decreased by all methods and a good correlation was found among the three methods used. The serum prothrombin assay by means of the electroimmunoassay showed levels comparable to those observed in plasma, as expected. In the bidimensional electrophoresis system, plasma prothrombin appeared decreased but showed a normal mobility. Serum prothrombin in the same system showed the presence of three normal albeit reduced peaks or precipitates.

Chromogenic substrate (S-2238) prothrombin assay in prothrombin deficiencies and abnormalities. Lack of identity with clotting assays in congenital dysprothrombinemias

Prothrombin was assayed using chromogenic substrate of S-2238 for patients who were being treated with coumarin, for patients who had liver disease, and for patients who had congenital hypoprothrombinemias and dysprothrombinemias. In coumarin therapy and in patients with liver disease the levels found correlated well with the one-stage clotting methods. The same was true for heterozygous and homozygous "true" prothrombin deficiency. In the case of congenital dysprothrombinemias the levels observed with the chromogenic substrate were higher than the clotting counterparts, particularly so in the case of prothrombin Padua. In the latter case the levels observed were always about 100% of normal, as compared with the levels of about 50% of normal found with clotting methods. These data indicate that chromogenic substrates are not always equivalent to "clotting" substrates, namely, that amidolytic activity is not always equivalent to clotting activity. Therefore the two methods cannot be used interchangeably, lest some defects escape detection.

Clotting changes in two patients with longitudinal sinus thrombosis

Two patients with angiographically proven longitudinal sinus thrombosis were studied from a coagulation point of view. In the first case, marked primary thrombocytosis was found. This patient was treated with aspirin, dipyridamole and radioactive phosphorus. In the second case, fibrinogen and whole blood plasma viscosity were elevated. This patient developed deep vein thrombosis of the left leg a few weeks after the cerebral episode and was treated with coumarin drugs. The importance of a coagulation study in every patient with cerebral vein thrombosis is emphasized.

Increased whole blood viscosity on cooling in a patient with cold hemoagglutinin disease

The whole blood and plasma viscosities have been evaluated in a patient with cold hemoagglutinin disease at different temperatures and at different shear rates. At 37 and 42 degrees C, whole blood viscosity values, regardless of the shear rate applied, resulted to be correspondent to the hematocrit value (31%). The values observed were similar to those noted in a patient with chronic bleeding anemia and an approximately equivalent hematocrit (33%). The same was true for plasma viscosity. At 32 degrees C, whole blood viscosity, regardless of the shear rate, resulted to be higher than expected. The values observed were similar to those noted in a normal subject with a clearly higher hematocrit value (44%) and definitely higher than those noted in the chronic anemia patient. On the contrary, plasma viscosity remained unchanged. These studies indicate that in cold hemoagglutinin disease, red cell aggregation and piling are capable of increasing blood viscosity.

An immunological investigation of factor VIII associated antigen in combined factor V and factor VIII deficiency

The behavior of factor VIII associated antigen of three patients with combined factor V and factor VIII deficiency has been evaluated in several immunological systems. Factor VIII associated antigen resulted to be normal or higher than normal in all three patients in the radial immunodiffusion and in the electroimmunoassay systems. In the bidimensional electrophoresis system only one factor VIII precipitate was evident and such factor VIII precipitate showed the same electrophoretic mobility as normal factor VIII antigen. These findings firmly establish the fact that the factor VIII defect in congenital combined factor V and factor VIII deficiency is of the hemophilia type.

Decrease of normotest/thrombotest discrepancy in non-contacted coumarin plasma after glass or ellagic acid activation

Activation of coumarin plasmas in glass tubes for 60 min resulted in a clear shortening of Thrombotest clotting times. Normotest clotting times were shortened too but to a much lesser extent. As a consequence the Normotest (NT)/Thrombotest (TT) discrepancy which was quite large at 0 time, became progressively smaller. This phenomenon was observed both in undiluted and 6:10 diluted plasma. After ellagic acid activation a similar phenomenon was noted even though a less pronounced shortening of Thrombotest was noted. These data suggest that Thrombotest is very sensitive to contact phase and to factor VII activation and not to any coumarin-induced inhibitors.

Combined deficiency of factor V and factor VIII. A report of another case

A patient with combined factor V and factor VIII deficiency is presented. The bleeding manifestations were: easy bruising, post-traumatic bleeding, bleeding after tooth extractions. The main laboratory feature was a prolonged partial thromboplastin time which was corrected by the addition of adsorbed normal plasma but not by the addition of normal serum, hemophilia A plasma of another patient with combined factor V and factor VIII deficiency. The thromboplastin generation test was clearly abnormal and was corrected by the addition of adsorbed normal plasma but not by addition of normal serum. Prothrombin consumption was also defective. Prothrombin time was slightly prolonged too, Thrombin time, platelet and vascular tests were within normal limits and there was no hyperfibrinolysis. Factor VIII was 8% of normal, whereas factor V was 14% of normal. Factor VIII associated antigen was normal. All other clotting factors were within normal limits. The parents of the propositus were consanguineous (first cousins) but had normal factor V and factor VIII activity and normal factor VIII antigen. The same was true for other family members. The hereditary transmission of the condition appears autosomal recessive.

Combined congenital deficiency of factor V and factor VIII. Report of a further case with some considerations on the hetereditary transmission of this disorder

A patient with combined factor V and factor VIII deficiency is presented. The bleeding manifestations were mild. The main laboratory feature was a prolonged partial thromboplastin time which was corrected by the addition of adsorbed normal plasma but not by the addition of normal serum, hemophilia A plasma or plasma of another patient with combined factor V and factor VIII deficiency. TGT was also clearly abnormal and was corrected by the addition of adsorbed normal plasma but not by the addition of normal serum. Prothrombin consumption was mildly defective. The prothrombin time was slightly prolonged. Facotr VIII was 12% and factor V 55% of normal. Factor-VIII-associated antigen was normal. The father and a sister of the propositus revealed mild factor V deficiency but normal factor VIII activity and antigen. The parents were not consanguineous. A tentative classification of combined deficiency of factors V and VIII in two groups is proposed. The hereditary transmission of the two types of deficiencies is discussed.

Viper venoms and coumarin-induced prothrombin. A comparison of several one-stage methods employing three different venoms as thromboplastins

Three venoms obtained from three vipers, namely Echis carinatus, Notechis scutatus scutatus and Oxyuranus scutellatus, have been used as thromboplastin in a one-stage assay of coumarin-induced prothrombin. Regardless of the venom used, prothrombin resulted to be low in coumarin-treated patients. The mean values obtained were 27.2, 33.6, and 24.2%, respectively. These values were comparable to those obtained by means of the classical one-stage method (24.8%). A good correlation was observed among the different methods. However, the levels observed using the Notechis scutatus scutatus venom method were slightly higher as compared to those obtained by means of the other viper venoms and by means of the classical one-stage method. The three viper venoms used seem unable to activate coumarin-induced prothrombin. The levels obtained were in fact, in each instance, definitely lower than those observed immunologically. Methods which employ these viper venoms may be used in the evaluation of prothrombin in coumarin-treated patients.

Factor X Friuli coagulation disorder. Report of a newly recognized patient and some considerations on the frequency of the disease in the Friuli area

A newly recognized patient with the factor X Friuli coagulation disorder is presented. The propositus is a 10-year-old boy who presented excessive bleeding after a tooth extraction. This is the 11th patient with this peculiar coagulation disorder discovered in Friuli and the 12th so far described. His parents are consanguineous and heterozygotes together with other family members. The main laboratory features, typical of the disease were prolonged prothrombin time, a prolonged partial thromboplastin time, and a normal Stypven-cephalin clotting time. The incidence of the homozygotes in the Friuli area appear to be 0.000005 (11 cases in a population of 2,000,000). The probable frequency of the abnormal f gene is 0.0033, whereas that of the normal gene F is 0.9967. The theoretical frequency of the heterozygote, Ff condition is 0.007, namely 7 heterozygotes every 1,000 persons. However, only about 70 ascertained heterozygotes have been discovered so far.

The K-test (trypsin clotting time) in coumarin treated patients and in congenital deficiencies and abnormalities of the prothrombin complex

The behavior of K-test (Trypsin clotting time) has been studied in 38 patients on long-term coumarin therapy and in 19 patients with congenital coagulation disorders of the prothrombin complex. All coumarin treated patients showed a clear prolongation of the test. The results obtained were compared with the standard prothrombin time, the Hepato-Quick-test (P-P test) and the Factor II + X test values, observed in the same patients. A good correlation was observed in each instance. The highest correlation was observed between K-test and the Factor II + X test (r=+0,78;t=7,80;p less than 0.001). All congenital coagulation disorders of the prothrombin complex yielded a prolonged K-test value but for Factor VII deficiency. In three patients with this latter condition a perfectly normal value was obtained. The K-test together with the prothrombin time may be useful in the differential diagnosis of factor VII deficiency from factor X deficiency and from the factor X Friuli abnormality.