THROMBOPHILIA:ITS CAUSES AND A ROUGH ESTIMATE OF ITS PREVALENCE

1987 ◽  
Author(s):  
E Briët ◽  
L Engesser ◽  
E J P Brommer ◽  
A W Broekmans ◽  
R M Bertina

Idiopathic venous thrombosis and embolism have gained widespread interest since the discovery that, deficiencies of antithrombin III, protein C, and protein S are associated with familial venous thrombophilia. The purpose of our study was to obtain an estimate of the prevalence of this syndrome and to establish the etiology in as many cases as possible.We collaborated with specialists from 37 Dutch hospitals, covering about 10% of the Dutch population. A history as well as blood samples were obtained from 113 unrelated cases with familial thrombophilia and from 90 isolated cases. Assuming that each proband in a family with thrombophilia has an average of four affected relatives, a rough estimate of the prevalence of familial thrombophilia in The Netherlands is 40 cases per 100.000. The prevalence of non-familial thrombophilia is probably lower.In 35 out of the 113 familial cases we established a diagnosis of hereditary antithrombin III deficiency (n=5), protein C deficiency (type I: n=9; type II: n=4), protein S deficiency (n=15) and dysfibrinogenemia (n=2). In 36 cases we found no abnormality at all and in the remaining 42 cases abnormalities were found in one or more of the following: heparin cofactor II, factor V, factor VII, factor VIII, von Willebrand factor, plasminogen, tissue plasminogen activator, plasminogen activator inhibitor, alpha 2 antiplasmin and histidine rich glycoprotein. In most of these cases, however, the hereditary nature of the abnormalities could not be demonstrated and the causal relationships remain to be established.In the 90 isolated cases, we diagnosed hereditary deficiencies of anti thrombin III, protein C and protein S each in one case and a lupus anticoagulant in two cases. In 54 cases no abnormality was found and in the remaining 31 cases various abnormalities were found in one or more of the proteins mentioned above.We conclude that the syndrome of thrombophilia is not rare but its true prevalence needs to be established by more rigorous means. An etiological diagnosis can be made with confidence in only one third of the familial cases and in less than 10 percent of the isolated cases.

1987 ◽  
Vol 57 (01) ◽  
pp. 020-024 ◽  
Author(s):  
A W Broekmans ◽  
J Conard ◽  
R G van Weyenberg ◽  
M H Horellou ◽  
C Kluft ◽  
...  

SummaryFive type I protein C deficient male patients received 5 mg stanozolol b.i.d. during 4 weeks. After four weeks of treatment plasma protein C activity increased from 0.42 to 0.74 U/ml and protein C antigen from 0.49 to 0.75 U/ml. This approximately 1.6 fold increase in plasma protein C was accompanied by an increase in factor II antigen (1.5 fold), factor V activity (1.6 fold), factor X antigen (1.1 fold), antithrombin III antigen (1.3 fold) and heparin cofactor II antigen (1.5 fold), while the concentration of factor VII, factor VIII, and factor IX activity, and of protein S antigen remained unchanged. Prothrombin fragment F1+2, measured in two patients, increased 1.3 fold. In addition to its effect on procoagulant and anticoagulant factors stanozolol had profibrinolytic effects, reflected in an increase in tPA activity and in the concentration of plasminogen. These data indicate that in type I protein C deficient patients stanozolol increases the concentrations of both procoagulant and anticoagulant factors and favours fibrinolysis. The efficacy of stanozolol in preventing thrombotic disease in type I protein C deficient patients, however, remains to be established. During the four weeks of stanozolol treatment no thrombotic manifestations were observed in the protein C deficient patients.


1987 ◽  
Author(s):  
P M Mannuccl ◽  
A Tripodl

The prevalence of inherited thrombotic syndromes in the general population (1 in 2,500/5,000) appears to be higher than that of inherited bleeding disorders. We have reviewed the problems of their diagnosis and propose a simple screening procedure. The most important candidates far. screening are patients with unexplained venous thromboembolism at ages ofless than 40 years, particularly when thrombotic episodes are recurrent.Screening must start from collectionof the clinical and family history of the propositus and from the exclusion of common acquired forms of thrombophilia. A negative family historydoes not exclude inherited thrombophilia, because the defects have oftena low penetrance and fresh mutationsmay have occurred in the propositi. The test chosen for laboratoryscreening of inherited thrombotic syndromes must be limited in number, easy todo and, more importantly, their results should be clinically relevent Which defects should be screened and what type of methodology should be used? The table is intended to answerthese questions by proposing a two-step screening procedure.The tests included in the .first step of the screening are aimed at evaluating Laboratory screening of inherited thrombotic syndromes the most frequent and well established causes of inherited thrombophilia, —-antithrombin III, protein C. protein S.plasminogen and fibrinogen.FIRST STEP Antithrombin III (heparin cofactorI chromogenic assay)Protein C (Francis' clotting assay)Protein S(electroimmunoassay of total proteinSantigen)Plasminogen (chromogenic assay)Fibrinogen (clotting assay)SECONSTEP(Tran's functional assay) Plasminogen activator (fibrin plate assay before and after venous stasisor DDAVP)Plasminogen activator inhibitor(chromogenic assay)The tests offirst choice that we propose (see table) are in general functional assaysdetecting both type I and type IIdeficiencies and are simple enough tobecarried out even in non specialized laboratories.For protein S, however,this goal has not been achieved yet and only type I protein S deficiencycan be currently identified with immunoassays measuring total protein S antigen. Since a number of laboratories may still not have the facilities to perform protein C functional assays, they are advised to set up at least an immunoassay, since type I deficiencies are much more frequent than type II deficiencies. The tests included in the second step of the screening are aimed at detectingthe less common or less well established causes of thrombophilia, and should be carried out when the clinical history suggests the existence of inherited thrombophilia and yet the first step has failed to reveal any laboratory abnormality. Defective plasminogen activation can be evaluated by measuring plasminogen activator activity with the simple fibrin plate assay carried out before and after stimuli such as venous occlusion and/or DDAVP infusion. The parallel measurement of plasminogen activator inhibitor allows to distinguish cases of detective plasminogen activation due to high inhibitor levels. The measurement of heparin cofactor II should also be included in this battery of second-step screening tests.Using this screening procedure in95 propositi with juvenile venous thromboembolism, we have identified 7 kindreds with antithrombin III deficiency (5 type I and 2 type II) (7.5%),7 kindreds with protein C deficiency (1 type II) (7.5%), 5 kindredswith protein S deficiency (5%), 1 withhypoplasminogenemia (1%) and 1 with dysfibrinogenemia Milano II (1). Theremaining undiagnosed cases might bedue to as yet unidentified deficiencies or abnormalities of other antithrombotic mechanisms such as,for instance, endothelial thrombomodulin or the fibrinolysis enhancing property of the protein C-protein S system.


1988 ◽  
Vol 59 (01) ◽  
pp. 018-022 ◽  
Author(s):  
C L Gladson ◽  
I Scharrer ◽  
V Hach ◽  
K H Beck ◽  
J H Griffin

SummaryThe frequency of heterozygous protein C and protein S deficiency, detected by measuring total plasma antigen, in a group (n = 141) of young unrelated patients (<45 years old) with venous thrombotic disease was studied and compared to that of antithrombin III, fibrinogen, and plasminogen deficiencies. Among 91 patients not receiving oral anticoagulants, six had low protein S antigen levels and one had a low protein C antigen level. Among 50 patients receiving oral anticoagulant therapy, abnormally low ratios of protein S or C to other vitamin K-dependent factors were presented by one patient for protein S and five for protein C. Thus, heterozygous Type I protein S deficiency appeared in seven of 141 patients (5%) and heterozygous Type I protein C deficiency in six of 141 patients (4%). Eleven of thirteen deficient patients had recurrent venous thrombosis. In this group of 141 patients, 1% had an identifiable fibrinogen abnormality, 2% a plasminogen abnormality, and 3% an antithrombin III deficiency. Thus, among the known plasma protein deficiencies associated with venous thrombosis, protein S and protein C. deficiencies (9%) emerge as the leading identifiable associated abnormalities.


1996 ◽  
Vol 76 (04) ◽  
pp. 505-509 ◽  
Author(s):  
F Bernardi ◽  
C Legnani ◽  
F Micheletti ◽  
B Lunghi ◽  
P Ferraresi ◽  
...  

Summary305 patients with juvenile thromboembolic episodes were screened for the presence of heparin cofactor II deficiency. The heterozygous deletion of two bases was found in the exon 5 of the heparin cofactor II gene in two unrelated patients, very likely due to a founder effect. This molecular lesion, causing a frameshift and elongated translation, affects the core of the molecule and should cause the complete unfolding of the protein, which is in accordance with the observed type I deficiency. The corresponding region of antithrombin III gene is affected by a cluster of frameshift mutations suggesting that heparin cofactor II and antithrombin III could share similar mutational patterns.The heparin cofactor II gene alteration was associated with, in one patient, the factor V Leiden mutation and, in the other, type I protein C deficiency. The tracing of the single defects in several family members indicated that the mutations became clinically manifest only when present in the doubly heterozygous condition. This study provides two examples, based on molecular findings, of the interplay of risk factors which is potentially useful to define a role for heparin cofactor II deficiency in inherited thrombophilia.


2001 ◽  
Vol 85 (01) ◽  
pp. 82-87 ◽  
Author(s):  
Bruce Scott ◽  
Peter Callas ◽  
Sandra Hasstedt ◽  
Mark Leppert ◽  
Julia Valliere ◽  
...  

SummaryThe incomplete penetrance of thrombosis in familial protein C deficiency suggests disease occurs when this deficit is combined with additional abnormalities in the hemostatic system. The pattern of inherited thrombophilia in the Vermont II kindred, which is affected by a clinically dominant type I protein C deficiency, provides strong evidence for a second unidentified gene that segregates independently of protein C deficiency and increases susceptibility to thrombosis. To test the second gene hypothesis, thirty-four candidate genes for proteins involved in hemostasis or inflammation were tested as the unknown defect, using highly polymorphic short tandem repeat (STR) markers in an informative subset (n = 31) of the kindred. The genes considered are; α-fibrinogen, β-fibrinogen, γ-fibrinogen, prothrombin, tissue factor, factor V, protein S, complement component 4 binding protein, factor XI, factor XII, factor XIIIa, factor Xlllb, histidine rich glycoprotein, high molecular weight kininogen, kallikrein, von Willebrands factor, platelet factor 4, thrombospondin, antithrombin III, α-1-antitrypsin, thrombomodulin, plasminogen, tissue plasminogen activator, urokinase plasminogen activator, plasminogen activator inhibitor-1, plasminogen activator inhibitor-2, protein C inhibitor, α-2-plasmin inhibitor, kallistatin, lipoprotein a, interleukin 6, interleukin 1, cystathionine-β-synthase, and methylenetetrahydrofolate reductase. Mutations in many of these genes have been previously established as independent risk factors for thrombosis. However, linkage analysis provided no evidence to implicate any of the candidate genes as the second inherited factor that promotes thrombophilia in this kindred.


1999 ◽  
Vol 81 (04) ◽  
pp. 527-531 ◽  
Author(s):  
U. Kjellberg ◽  
N.-E. Andersson ◽  
S. Rosén ◽  
L. Tengborn ◽  
M. Hellgren

SummaryForty-eight healthy pregnant women were studied prospectively and longitudinally. Blood sampling was performed at 10-15, 23-25, 32-34 and 38-40 weeks of gestation, within one week and at eight weeks postpartum. Classic and modified activated protein C ratio decreased as pregnancy progressed. In the third trimester 92% of the ratios measured with the classic test were above the lower reference level whereas all modified test ratios were normal. Slight activation of blood coagulation was shown with increased levels of prothrombin fragment 1+2, soluble fibrin and D-dimer. Fibrinogen, factor VIII and plasminogen activator inhibitor type 1 and type 2 increased. Protein S and tissue plasminogen activator activity decreased. Protein C remained unchanged. No correlation was found between the decrease in classic APC ratio and changes in factor VIII, fibrinogen, protein S, prothrombin fragment 1+2 or soluble fibrin, nor between the increase in soluble fibrin and changes in prothrombin fragment 1+2, fibrinogen and D-dimer.


1988 ◽  
Vol 60 (02) ◽  
pp. 328-333 ◽  
Author(s):  
N J de Fouw ◽  
Y F de Jong ◽  
F Haverkate ◽  
R M Bertina

summaryThe effect of purified human activated protein G (APC) on fibrinolysis was studied using a clot iysis system consisting of purified glu-plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor (released from endothelial cells or blood platelets), fibrinogen, 125T-fibrinogen and thrombin. All proteins were of human origin.In this system APC could increase fibrinolysis in a dose dependent way, without affecting fibrin formation or fibrin crosslinking. However, this profibrinolytic effect of APC could only be observed when plasminogen activator inhibitor (PAI-l) was present. The effect of APC was completely quenched by pretreatment of APC with anti-protein C IgG or di-isopropylfluorophosphate. Addition of the cofactors of APC:protein S, Ca2+-ions and phospholipid-alone or in combination did not enhance the profibrinolytic effect of APC. These observations indicate that human APC can accelerate in vitro clot lysis by the inactivation of PAI-1 activity. However, the neutralization of PAI-1 by APC is independent of the presence or absence of protein S, phospholipid and Ca2+-ions.


Author(s):  
A.A. Abrishamizadeh

Ischemic stroke (IS) is a common cause of morbidity and mortality with significant socioeconomic impact especially when it affects young patients. Compared to the older adults, the incidence, risk factors, and etiology are distinctly different in younger IS. Hypercoagulable states are relatively more commonly detected in younger IS patients.Thrombophilic states are disorders of hemostatic mechanisms that result in a predisposition to thrombosis .Thrombophilia is an established cause of venous thrombosis. Therefore, it is tempting to assume that these disorders might have a similar relationship with arterial thrombosis. Despite this fact that 1-4 % of ischemic strokes are attributed to Thrombophillia, this   alone rarely causes arterial occlusions .Even in individuals with a positive thrombophilia screen and arterial thrombosis, the former might not be the primary etiological factor.Thrombophilic   disorders can be broadly divided into inherited or acquired conditions. Inherited thrombophilic states include deficiencies of natural anticoagulants such as protein C, protein S, and antithrombin III (AT III) deficiency, polymorphisms causing resistance to activated protein C(Factor V Leiden mutation), and disturbance in the clotting balance (prothrombin gene 20210G/A variant). Of all the inherited  thrombophilic disorders, Factor V Leiden mutation is perhaps the commonest cause. On the contrary, acquired thrombophilic disorders are more common and include conditions such as the antiphospholipid syndrome, associated with lupus anticoagulant and anticardiolipin antibodies.The more useful and practical approach of ordering various diagnostic tests for the uncommon thrombophilic states tests should be determined by a detailed clinical history, physical examination, imaging studies and evaluating whether an underlying hypercoagulable state appears more likely.The laboratory thrombophilia   screening should be comprehensive and avoid missing the coexisting defect and It is important that a diagnostic search protocol includes tests for both inherited and acquired thrombophilic disorders.Since the therapeutic approach (anticoagulation and thrombolytic therapy) determines the clinical outcomes, early diagnosis of the thrombophilic  disorders plays an important role. Furthermore, the timing of test performance of some of the  thrombophilic  defects (like protein C, protein S, antithrombin III and fibrinogen levels) is often critical since these proteins can behave as acute phase reactants and erroneously elevated levels of these factors may be observed in patients with acute thrombotic events. On the other hand, the plasma levels of vitamin K-dependent proteins (protein C, protein S and APC resistance) may not be reliable in patients taking vitamin K antagonists. Therefore, it is suggested that plasma-based assays for these disorders should be repeated3 to 6 months after the initial thrombotic episode to avoid false-positive results and avoid unnecessary prolonged   anticoagulation therapy. The assays for these disorders are recommended after discontinuation of oral anticoagulant treatment or heparin for at least 2 weeks.    


Author(s):  
J Malm ◽  
M Laurell ◽  
I M Nilsson ◽  
B Dahlbäck

Consecutive patients with a history of thrombo-embolic disease (n = 241, 109 males, 132 females, mean age 46 y), referred to the Coagulation Laboratory during an 18 month period, were analysed for defects in their coagulation and fibrinolytic systems. The diagnosis of thrombosis had been verified with phlebography and that of pulmonary embolus with scintigraphy or angiography. Retinal venous thrombosis was found in 15 of the patients. In 15 cases the thrombotic episodes occurred postoperatively, in 15 during pregnancy, in 12 during the postpartum period and in 20 during use of oral contraceptives. In the remaining cases no clinical riskfactors were identified.The concentration of protein C zymogen was measured with an immunoradiometric assay. Functional protein C was determined with a clotting inhibition assay. Protein C deficiency was found in 8 cases. Two of these had a functional protein C deficiency with normal zymogen levels. The concentration of total, as well as free (not in complex with C4b-binding protein), protein S was determined with a radioimmunoassay. Two cases of protein S deficiency were detected. Three patients with antithrombin III deficiency and two with plasminogen deficiency were found.The fibrinolytic activity after venous occlusion was analysed in 216 patients. Decreased levels were found in 32 %. The concentration of tissue plasminogen activator inhibitor (PAI) was measured in 110 patients and found to be increased in 65 % of the cases. In 99 patients both the fibrinolytic activity and the PAI concentration were measured. A combination of decreased fibrinolytic activity and increased levels of PAI was found in 44 cases. The concentration of tissue plasminogen activator antigen was decreased in 22 % of 105 cases analysed.Thus, in this material of patients with thrombo-embolic disease, abnormalities were found in 47 %. Defects in the fibrinolytic system were the most common findings. Protein C or protein S deficiency was diagnosed in less than 5 % of the cases.


Sign in / Sign up

Export Citation Format

Share Document