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PubMedDate not supplied

A combined deficiency of factor VIII and contact activation defect in a family of cats.

The coagulation parameters of a litter of kittens born to an obligate carrier of haemophilia A (classical haemophilia, factor VIII deficiency) are described. Three of four kittens were found to have an intrinsic coagulation defect, but only one was haemophilic. Factor XII deficiency was confirmed in one female, the other female and the dam being carriers of the defect. A confirmed haemophilic male from a previous litter was also found to be a factor XII deficient carrier.

Animals↗
PubMed1988

A frequent factor XII gene mutation in Hageman trait.

An additional TaqI restriction site was mapped in intron 2 of the factor XII gene. The site was found only in subjects with total or partial factor XII deficiency and thus represents the true gene lesion or a very tightly linked restriction fragment length polymorphism. The altered gene identified by this marker is present in four (three heterozygotes and one homozygote) of five unrelated Hageman trait subjects from different Italian regions. In the homozygous state the altered gene gives rise to a very marked reduction of factor XII activity. No deletion was found in the deficient factor XII genes.

Blotting, Southern↗
PubMed1991

An analysis of the activators of single-chain urokinase-type plasminogen activator (scu-PA) in the dextran sulphate euglobulin fraction of normal plasma and of plasmas deficient in factor XII and prekallikrein.

An analysis was made of the various possible activators of single-chain urokinase-type plasminogen activator (scu-PA) in the dextran sulphate euglobulin fraction (DEF) of human plasma. scu-PA activators were detected in an assay system in which the substrate scu-PA, in physiological concentration (50 pM), was immuno-immobilized. After activation of the immobilized scu-PA for a certain period of time the activity of the generated amount of immuno-immobilized two-chain u-PA was determined with plasminogen and the chromogenic substrate S-2251. The scu-PA activator activity (scuPA-AA) in the DEF of plasmas deficient in factor XII or prekallikrein was about half of that in the DEF of normal plasma. Separation of scuPA-AA in the DEF by gel chromatography showed to major peaks, one eluting with an apparent Mr of 500,000 and the other around Mr 100,000. The former peak, which coincided with the activity peak of the kallikrein-kininogen complex, was absent in the DEF of plasma depleted of prekallikrein and therefore was identified as kallikrein. The latter peak was still present in the depleted plasma and most likely represents plasmin, because its scuPA-AA coincided with the activity peak of plasmin and could be fully inhibited by antibodies raised against human plasminogen. It is concluded that plasmin and the contact-activation factor kallikrein each contribute for about 50% to the scuPA-AA in the DEF. Compared on a molar basis, however, plasmin was found to be almost 1,000 times more effective than kallikrein, and we conclude, therefore, that in vivo plasmin is the primary activator of scu-PA and the role of the contact system is of secondary importance.

Chemical Fractionation↗
PubMed2005

Subdural hematoma in a patient with Hageman trait--case report.

A 61-year-old man with severe factor XII deficiency presented with a subdural hematoma appearing as mixed but mainly high density by computed tomography in the left frontotemporoparietal region. No cranial injury was reported in the medical history of the patient. Clotting system study showed less than 1% functional activity of factor XII, whereas the levels of the other clotting factors were within the normal ranges. Partially clotted and hemolyzed subdural hematoma was removed through a craniotomy. The postoperative course was uneventful. The patient later died of severe circulatory-respiratory failure. We believe that the subdural hematoma may have developed as a result of a minor head trauma sustained in the past. We suggest that impairment of fibrinolytic activation related to severe factor XII deficiency might have contributed to the delay of dissolution of the subdural hematoma which, under ordinary circumstances, would have formed chronic subdural hematoma.

Factor XII Deficiency↗
PubMed1986

Prekallikrein deficiency in a family of miniature horses.

Two sibling miniature horses, a male and a female, had a normal 1-stage prothrombin time and a prolonged activated-partial thromboplastin time (APTT). The addition of as little as 5% of a normal equine plasma pool to the plasma samples of both horses shortened their prolonged APTT to within normal limits. Coagulation factor analysis revealed deficiencies in factor XII (12 and 13 U/dl, control population 77 to 128 U/dl), when determined with a feline factor XII-deficient plasma substrate, but normal concentrations (119 and 96 U/dl) when a human factor XII-deficient plasma substrate was used. Deficiencies of another factor, prekallikrein, were detected with a human prekallikrein-deficient plasma substrate (16 and 6 U/dl, control population 70 to 173 U/dl). Other intrinsic coagulation factors were present in normal concentrations. The APTT was measured with plasma from the 2 horses after various incubation periods (1 to 15 minutes) with a contact activator before the addition of Ca ions. With incubation times of greater than or equal to 10 minutes, the APTT of both horses were essentially the same as that of the normal equine plasma pool. Several family members of the 2 prekallikrein-deficient miniature horses appeared to be heterozygous carriers of the prekallikrein deficiency.

Animals↗
PubMed1980

Hemophilia A in a phenotypic female with normal male karyotype associated with a low factor XII level.

Hemophilia A was detected in a 40-year-old black Gabonese female prior to thoracic surgery for empyema. The diagnosis of mild hemophilia A was supported by the findings of low factor VIII coagulant activity (VIII:C 4%), normal levels of factors VIII related antigen (VIIIR:Ag) and VIII von Willebrand (VIIIR:WF), without detectable circulating anticoagulant. Neither the patient nor her immediate relatives had past histories of abnormal bleeding. The physical features were phenotypically female with developed breasts, pubic hair and normal external genitalia: however, she had primary amenorrhea, a blind vagina with no uterus and her karyotype was 46,XY. These findings are consistent with the diagnosis of testicular feminization thereby explaining the apparent contradiction between the phenotype and the known six-linked inheritance of hemophilia A. In addition to factor VIII deficiency a low level of factor XII (20%) was detected although it cannot be concluded whether the patient is truly factor XII deficient or whether she represents a low variant of the normal distribution.

Adult↗
PubMed1978

Deficiency of factor XII-dependent plasminogen proactivator in prekallikrein-deficient plasma.

Normal human plasma contains a factor XII (Hageman factor)-dependent plasminogen proactivator in its gamma globulin fraction. On the basis of both fibrin plate and clot lysis assays, this plasminogen proactivator activity was shown to be absent from the gamma globulin fraction of prekallikrein (Fletcher factor)-deficient plasma of two unrelated patients. This observation suggests that factor XII-dependent plasminogen proactivator is identical to plasma prekallikrein.

Blood Coagulation Disorders↗
PubMed1997

Respective evaluation of the prevalence of haemostasis abnormalities in unexplained primary early recurrent miscarriages. The Nimes Obstetricians and Haematologists (NOHA) Study.

The prevalence of haemostasis abnormalities was evaluated in 500 consecutive women with unexplained primary recurrent miscarriages. Two matched reference groups with no antecedent of miscarriage were studied: 100 healthy mothers and 50 childless women. In the prospective part of the study, we found 9.4% of the patients (95% C.I.: 6.8-12%) with an isolated factor XII deficiency, 7.4% of the patients (5.0-9.8%) with primary antiphopholipid antibodies, 47% of the patients (42.6-51.4%) with an insufficient response to the venous occlusion test and an isolated hypofibrinolysis was found in 42.6% (38.2-47%) of the patients (reference groups: respectively 0/150, 3/150, 2/150, p < 10(-3)). Willebrand disease, fibrinogen, deficiency, antithrombin, protein C or protein S deficiencies were not more frequent in recurrent aborters than in members of the reference groups. In the retrospective part of the study, cases of plasma resistance to activated protein C were not abnormally frequent. Patients had higher Willebrand factor antigen (vWF), tissue-type plasminogen activator antigen (t-PA), plasminogen activator inhibitor activity (PAI) and D-dimers (D-Di) than the reference women. Values of vWF, t-PA, PAI and D-Di were altogether correlated but were not related to C-reactive protein concentrations. Among patients, those with an antiphospholipid syndrome and those with an insufficient response to the venous occlusion test had higher vWF, t-PA, PAI and D-Di values than the patients with none of the haemostasis-related abnormalities. Thus, factor XII deficiency and hypofibrinolysis (mainly high PAI) are the most frequent haemostasis-related abnormalities found in unexplained primary recurrent aborters. In patients with antiphospholipid antibodies or hypofibrinolysis, there is a non-inflammatory ongoing chronic elevation of markers of endothelial stimulation associated with coagulation activation. This should allow to define subgroups of patients for future therapeutic trials.

Abortion, Habitual↗
PubMed1994

Varicella and thrombotic complications associated with transient protein C and protein S deficiencies in children.

We report six cases of protein S deficiency secondary to varicella. Five cases were complicated by thrombotic and vascular events, namely purpura fulminans and necrotic vasculitis, deep vein thrombosis and stroke. Two cases were associated with protein C deficiency and one case revealed a heterozygous factor XII deficiency. The underlying mechanism of this acquired protein S deficiency is unclear but could be related to a direct effect of zoster virus.

Chickenpox↗
PubMed1988

[Disorders in the contact phase system of blood coagulation as a cause of increased partial thromboplastin time].

Deficiency conditions in the contact phase system of the blood coagulation belong to the rare hereditary defects. Clinically, there is as a rule no inclination to haemorrhage but an increased risk of thrombosis. Therefore, the diagnosis is frequently made on the basis of incidental findings within the framework of routine examinations. Indicating sign is a greatly prolonged partial thromboplastin time (PTT) without clinical signs of haemorrhage. 3 patients with factor XII deficiency are presented and the diagnostic method in prolonged PTT is explained.

Blood Coagulation Tests↗
PubMed1990

Determination of the minimal concentrations of contact activation factors in deficient substrate plasmas required to assess accurately factor XII, factor XI, factor IX, and high molecular weight kininogen.

Using combined deficient plasmas prepared by passage of a deficient plasma over an anti-factor XI-monoclonal antibody column, we have determined the threshold concentrations of each coagulation factor of contact phase in factor-deficient substrate plasmas required to determine accurately the functional activities of factor XII, factor XI, factor IX and high molecular weight kininogen (HMWK). In order to reliably quantitate factor XI and factor IX activity levels, at least 20% factor XII and 20% factor XI, respectively, were required in the deficient substrate plasmas. In the assessment of factor XII activity, approximately 40% factor XI was required in the factor XII-deficient substrate plasma. On the other hand, only 11-12% factor XI or HMWK was required in the deficient substrate plasmas in the assessment of these two clotting factors. Our data emphasize that deficiencies of other clotting factors may reduce the apparent activity of the clotting factor in question if their concentration is rate-limiting in the clotting assay.

Blood Coagulation Disorders↗
PubMed1978

[Factor XII (HAGEMAN FACTOR)].

The discovery of factor XII (Hageman factor), the attempts of characterizing it, the knowledge of its presence of absence in the various vertebrate classes are represented in a survey and recent opinions of molecular biology about its structure and composition are discussed. The effect of the activating substances for transferring the Hageman factor into its active form are represented with the role of the pre-kallikrein (Fletcher factor) and of the highly molecular kininogen (Fitzgerald factor) being referred to. Furthermore, the following systems influenced by factor XII are dealt with: 1. The endogenous and exogenous activating system of blood clotting and possible reasons for lower bleedings with factor XII deficiency. 2. Role of the Hageman factor in activating fibrinolysis. 3. Influence on the liberation of kinin. 4. Correlations towards the complement system. 5. Possible inhibitory effect of platelet aggregation. Finally the close connection of all these systems is referred to and the necessity of considering these complicated events in a complex way is stressed.

Blood Coagulation↗
PubMed2001

Phosphatidylethanolamine participates in the stimulation of the contact system of coagulation by very-low-density lipoproteins.

We have analyzed the influence of plasma lipoproteins on the activation of the contact pathway of blood coagulation in platelet-rich plasma (PRP). The formation of thrombin in PRP incubated in vitro was abolished by the factor XIIa antagonist corn trypsin inhibitor and by severe factor XII deficiency, indicating mediation by the contact system. Addition of VLDL to the PRP shortened the lag period and increased the generation of thrombin. There was no effect of HDL and LDL. In whole blood, VLDL accelerated the rate of fibrin formation, the procoagulant effect being prevented by factor XII deficiency and by corn trypsin inhibitor. The thrombin formation in the PRP was strongly increased by microemulsions of the VLDL lipids while it was reduced by the aqueous phase of the particles. Separation of the VLDL lipids indicated the phospholipid component as the major activating principle. Vesicles supplemented with all VLDL phospholipids but lacking specifically the fraction containing phosphatidylethanolamine (PE) prolonged the lag time. The PE containing fraction alone as well as vesicles enriched with egg PE shortened the lag period. In summary, VLDL stimulates the contact pathway of blood coagulation, ethanolamine phospholipids being the most active components of the particles.

Adult↗
PubMed2006

Blood plasma contact activation on silicon, titanium and aluminium.

In the present work, blood plasma protein deposition to spontaneously air oxidized silicon, titanium and aluminium was re-investigated in vitro. Immunological- and null ellipsometry methods were used to detect and quantitate adsorbed proteins, RIA methods to study the retention of preadsorbed 125I-HSA upon exposure to buffer or blood plasma, and kallikrein-specific colorimetric substrate S-2302 to follow the surface generation of kallikrein. The results show that the contact activation of coagulation and complement systems are connected on Si and Ti, but not on Al, via coagulation factor XII. Preadsorbed 125I-HSA was most readily displaced on silicon, followed by titanium and aluminium. The surfaces displayed different antibody binding patterns after short and long-time exposures to plasma. Titanium and silicon bound anti-HMWK after 1 min in plasma, but aluminium did not. When the plasma incubation time was prolonged up to 2h the anti-HMWK binding disappeared totally on titanium and decreased on silicon. During the same time period, anti-C3c binding increased to the three types of surfaces. Also, the anti-C3c binding onto Si and Ti, but not Al, disappeared after incubation in Factor XII deficient plasma or when a specific coagulation factor XII (Factor XII) inhibitor, corn trypsin inhibitor (CTI) was added to normal plasma. The surface contacted plasmas cleaved the kallikrein-specific reagent S-2302 both after single surface contact, and after reincubation of surfaces in fresh plasma. The results show that C3b and Factor XIIa and their degradation products were retained at the surfaces.

Adsorption↗