Treatment of venous thrombosis in antithrombin III deficient patients with concentrates of antithrombin III

Summary Two patients with familial antithrombin III deficiency developed deep venous thrombosis of the lower limb. The diagnosis of venous thrombosis was made by the indium labelled platelet technique which also allowed for the daily assessment of thrombus size. Each patient received treatment with Warfarin, subcutaneous heparin, and infusions of antithrombin III concentrates. The authors conclude that infusions of antithrombin III concentrates may be of value in limiting the extent of acute thrombosis in patients with a severe deficiency of this protein and may help prevent pulmonary embolism. The haemorrhagic risk of continuing modest doses of heparin with high dose ATIII therapy appears small. In addition to its value in the diagnosis of venous thrombosis the indium platelet technique may give an early indication of thrombus extension and may thus indicate the effectiveness of treatment.     

Anti-coagulant therapy--antithrombin III

Biological properties and the efficacy of AT III concentrate for the treatment of thromboembolic disorders were evaluated in the patients with AT III deficiency. Commercially available AT III concentrates showed heterogeneity on agarose gel isoelectric focusing, however, they inhibited thrombin in the same manner. At III concentrates were infused to 11 patients with congenital AT III deficiency (4 with thrombosis). Pharmacokinetic parameters of infused AT III were calculated as follows; half time 61.1 +/- 23.0 hr. (58.4 +/- 22.6 hr. in the cases with thrombosis), max increase rate 1.01 +/- 0.3%/U/kg and recovery rate 95.4 +/- 33.3%. Simulation curves adjusted to the multiple administration were correlated well with the actually determined values in the patients and steady state concentration of AT III was achieved by the administration of this concentrate in 12 or 24 hour intervals. Clinically, substitution with AT III concentrate was proved to be effective for the treatment of thromboembolism in these patients. 16 patients with disseminated intravascular coagulation were treated with heparin (6,000 U/day) followed by AT III concentrate (1,500 U/day) administration. Clinical symptoms and laboratory findings were improved in 11 patients. From these results substitution with AT III concentrate was suggested to be beneficial for the prevention or the treatment of thromboembolic disorders in the patients with AT III deficiency.     

Treatment of venous thrombosis in antithrombin III deficient patients with concentrates of antithrombin III

Summary Two patients with familial antithrombin III deficiency developed deep venous thrombosis of the lower limb. The diagnosis of venous thrombosis was made by the indium labelled platelet technique which also allowed for the daily assessment of thrombus size. Each patient received treatment with Warfarin, subcutaneous heparin, and infusions of antithrombin III concentrates. The authors conclude that infusions of antithrombin III concentrates may be of value in limiting the extent of acute thrombosis in patients with a severe deficiency of this protein and may help prevent pulmonary embolism. The haemorrhagic risk of continuing modest doses of heparin with high dose ATIII therapy appears small. In addition to its value in the diagnosis of venous thrombosis the indium platelet technique may give an early indication of thrombus extension and may thus indicate the effectiveness of treatment.     

Antithrombin III Glasgow: a variant with increased heparin affinity and reduced ability to inactivate thrombin, associated with familial thrombosis

A functional antithrombin III (AT III) deficiency has been identified in two generations of a family with a high incidence of thrombosis. The deficiency presented as approximately 50% reduction in heparin cofactor activity compared to its antigen concentration. No abnormality was detected by crossed immunoelectrophoresis in the presence or absence of heparin. Plasma from the propositus was precipitated with dextran sulphate, applied to heparin-Sepharose and the AT III stepwise eluted with NaCl. The AT III had a reduced ability to inactivate thrombin, when this was monitored by substrate hydrolysis or by SDS polyacrylamide gel electrophoresis. Its mobility was normal by the latter technique using 10-20% gradient gels under reducing and non-reducing conditions. AT III from the patient was reapplied to heparin-Sepharose and eluted with a NaCl gradient. An active pool eluted in the same NaCl concentration range used to purify normal AT III, while predominantly inactive AT III eluted at higher NaCl concentrations. It is concluded that this variant, designated AT III Glasgow, has increased affinity for heparin but reduced ability to inactivate thrombin.     

Biology of recurrent venous thrombosis

Important recent advances in the field of the biology of recurrent venous thrombosis include greater understanding of congenital deficiency states involving antithrombin III (AT III) and protein C. Other disturbances demonstrated were related to fibrinolysis frequently, and rarely platelet function and coagulation factors. Possible existence of these anomalies requires investigation during biologic tests in cases of recurrent venous thrombosis, particularly in the presence of a family history or onset of the initial affection before 40 years of age. Confirmation of the importance of screening for such anomalies is supplied by results of a study of 11 families with antithrombin III deficiency and 9 families deficients in protein C, and a literature review of cases. However, currently available biologic tests provide data enabling only partial explanation of the mechanism underlying recurrent venous thrombosis accidents.     

Clinical use of intrapulmonary heparin

Of 16 patients treated with intrapulmonary heparin at doses between 10,000 and 20,000 U/week for 1592 patient days, or 4.3 years, only one rethrombosed. This patient has a congenital antithrombin III deficiency. However, the use of intrapulmonary heparin, even in this particular patient, has remarkably decreased her thrombotic events as manifested by studying her history of deep vein thrombosis and pulmonary embolism prior to starting intrapulmonary heparin. This represents a failure rate of 4.2% in the total of 1592 patient days of therapy, or a rethrombosis rate of 1.4% per year. This recurrence rate is far superior to that reported for warfarin-type therapy or for platelet suppressive therapy. From this limited experience, it appears that heparin is an extremely safe and highly effective mode of outpatient prophylaxis for deep vein thrombosis and thromboembolic disease. The ultimate aim of this study is to determine the possibility of calcium heparin being placed into a hand-held aerosol nebulizer that a patient can use at home on a weekly basis. This would provide a highly convenient, safe, and apparently very efficacious mode of therapy for the long-term outpatient prophylaxis of deep vein thrombosis and thromboembolic disease.     

Familial thrombosis due to antithrombin III deficiency in a Greek family.

A Greek family with hereditary antithrombin III (AT III) deficiency associated with venous thrombosis is reported. 5 members of the family were affected. In these patients, AT III and heparin cofactor activities were decreased. Immunoreactive AT III showed a positive correlation to both AT III and heparin cofactor activities. alpha2-Macroglobulin and alpha1-antitrypsin were normal. The pattern of inheritance of the defect is autosomal dominant.     

A comparison of antithrombin III procedures

Summary Antithrombin III (AT III) is the most potent physiologic inactivator of thrombin and other serine proteases in the blood clotting mechanism. Hereditary deficiency of this protein is associated with recurrent deep-vein thrombosis that begins in late adolescence. Untreated, this disease may lead to early death from recurrent and massive pulmonary emboli. Attempts to identify groups of patients who are the most likely to develop thromboembolic disease because of an acquired deficiency of AT III have been frustrated by the lack of standardization of the assays and the inability to compare results of the different AT III assays. The functional assays and immunoelectrophoretic determinations do not measure the same component. In order to compare the ability of current AT III procedures to determine levels of AT III in various disease states, we used immunoelectrophoretic, chromogenic, and clottable assays to measure the AT III of patients with congenital AT III deficiency and of patients with possible acquired AT III deficiency.     

Current concepts of warfarin therapy

Oral anticoagulants are used extensively, although their risks are not always fully recognized. The prophylaxis of venous thrombosis after hip surgery, the prevention of deep venous thrombosis and pulmonary emboli after an acute episode of these, the prevention of arterial emboli from the heart in patients at risk, and the prophylaxis of thrombosis in patients with congenital deficiency of antithrombin III, protein C, or protein S are some of the indications for oral anticoagulant use. Warfarin sodium is contraindicated in pregnancy, however. The recommended prothrombin time is 1 1/2 to two times control, lower than previously. The major risk of oral anticoagulant therapy, bleeding, is treated with vitamin K or plasma, depending on its severity. Warfarin necrosis and the "purple-toe" syndrome are seen more frequently than realized.     

Antithrombin III kumamoto II; A single mutation at Arg393-his increased the affinity of antithrombin III for heparin

Abnormal antithrombin III (AT III) was found in a 30-year-old woman who suffered from recurrent thrombosis during pregnancy and the postpartum period. Among her family members, only her father had recurrent episodes of deep vein thrombosis of the lower extremities, from his youth. The antithrombin and antifactor Xa heparin cofactor activities of the proposita's plasma were 61% and 42% of normal, respectively. The progressive antithrombin and antifactor Xa activities were also decreased to 55% and 58% of normal, respectively. The immunoreactive level of AT III was within the normal range (23.1 mg/dl). Analysis of the proposita's plasma by crossed immunoelectrophoresis in the presence or absence of heparin and by affinity chromatography on heparin-Sepharose revealed that the proposita's AT III had apparently normal affinity for heparin. Nucleotide sequencing of 7 exons of the proposita's AT III gene amplified by polymerase chain reaction (PCR) disclosed that the second base of codon 393 comprised both G and A, indicating Arg393-His conversion. The base sequences of exons 1,2,3a, 3b, 4, and 5 were normal, excluding any other mutation. These findings indicated that the proposita's AT III was a variant of AT III at the thrombin binding site and that the proposita was a heterozygote for the abnormality. Heparin affinity of purified abnormal AT III from the proposita's plasma was demonstrated to be increased upon affinity chromatography using heparin-Sepharose, suggesting that the mutation (Arg393-His) per se could possibly increase the affinity of antithrombin III for heparin. For this variant AT III (Arg393-His), the name AT III Kumamoto II is proposed. ©1995 Wiley-Liss, Inc.     

Treatment of mechanical aortic valve thrombosis with heparin and eptifibatide

A 75-year old woman with a history of coronary disease status post 3-vessel coronary artery bypass grafting (CABG) 8 years ago and a repeat one-vessel CABG 2 years ago in the setting of aortic valve replacement with a #19 mm St. Jude bileaflet mechanical valve for severe aortic stenosis presented with two to three weeks of progressive dyspnea and increasing substernal chest discomfort. Echocardiography revealed a gradient to 31 mmHg across her aortic valve, increased from a baseline of 13 mmHg five months previously. Fluoroscopy revealed thrombosis of her mechanical aortic valve. She was not a candidate for surgery given her multiple comorbidities, and fibrinolysis was contraindicated given a recent subdural hematoma 1 year prior to presentation. She was treated with heparin and eptifibatide and subsequently demonstrated resolution of her aortic valve thrombosis. We report the first described successful use of eptifibatide in addition to unfractionated heparin for the management of subacute valve thrombosis in a patient at high risk for repeat surgery or fibrinolysis.     

Management of planned pregnancy in a patient with congenital antithrombin III deficiency

Long-term warfarin therapy was changed to subcutaneous heparin to cover a planned pregnancy in a patient with congenital antithrombin III (AT III) deficiency. Satisfactory anticoagulation was easily maintained in spite of low levels of biologically active AT III. Delivery and the puerperium were covered by a reduced dose of heparin and alternate day infusions of AT III concentrate. A mean dose of 0.77 U/kg of AT III concentrate produced a rise of 1% in AT III and the half-life was of the order of 24 h, with no evidence of increased consumption during labour and delivery. Pregnancy and labour were uncomplicated and resulted in delivery of a healthy female infant. The importance of early and adequate anticoagulation during pregnancy is emphasized.     

An abnormal antithrombin III (AT III) with low heparin affinity: AT III Clichy

We have identified an inherited qualitative deficiency of antithrombin III (AT III) in a family with apparently no increased incidence of venous thrombosis. Plasma antithrombin and anti-Xa activities were normal, but the interaction with heparin, heparan sulphate and low molecular weight heparin was uniformly decreased. An immunoblotting technique performed in plasma showed normal complex formation with thrombin. By using heparin-Sepharose affinity chromatography and crossed immunoelectrophoresis, the variant could be separated: at least two fractions of low affinity AT III were obtained. A minor one had no antiprotease activity; the other one was further purified to homogeneity and found to have normal specific activity in absence of heparin and a 50% decreased activity in presence of heparin. We propose to call this new variant AT III Clichy.     

Early graft thrombosis due to antithrombin III deficiency following CABG

The serine protease inhibitor antithrombin III (AT-III), an ??2-globulin synthesized in the liver and endothelial cells, is the principal in vivo inhibitor of blood coagulation inactivating mainly thrombin. AT-III deficiency presents a rare hereditary or acquired disorder that most often comes to light when a patient suffers recurrent venous thrombosis and pulmonary embolism. Triggers for the onset of the thrombosis include various mechanisms such as pregnancy, delivery, surgery, trauma, and contraceptive pill use. Decreased response to heparin may be the first sign of AT-III deficiency. Since heparin is a conditio sine qua non for cardiopulmonary bypass, rapid consumption of AT-III promoted by heparin may lead to systemic thrombosis. The effect of heparin on graft patency after CABG in patients with AT-III deficiency, particularly with respect to early graft thrombosis, has not been fully investigated. The early detection and timely treatment of this disorder may impact perioperative morbidity. We present a case of simultaneous thrombosis of three venous grafts after elective coronary artery bypass surgery in a patient with AT-III deficiency.     

Prophylaxis of thrombosis in a pregnant woman with congenital antithrombin III deficiency: changes in hemostatic molecular markers before the onset of thrombosis]

A pregnant woman with congenital antithrombin III (AT III) deficiency was given AT III concentrate and warfarin at the first and after 36th week of gestation periods and at the other gestation period, respectively. The patient developed thrombosis in the left leg, but fibrinopeptide A (FPA) and thrombin-AT III complex (TAT) had already shown high values one week before, suggesting the possibility of their being forecast markers of thrombosis. The administration of AT III concentrate caused an improvement in thrombosis. Therefore, in case of high FPA and TAT values as determined one or two times a week, the administration of AT III concentrate was thought necessary. In case of warfarin, however, non-administration during the 6th-9th weeks of gestation for the purpose of avoiding teratogenicity and frequent blood coagulation tests taking heed of overdosage for the purpose of avoiding fetal central nervous system abnormalities were suggested necessary. Delivery was uneventful, both mother and child being doing very well; umbilical blood AT III activity was 18%. It is generally difficult for us to form the diagnosis as AT III deficiency only from AT III activity at neonatal stage, but in the present study, we analyzed the restriction fragment length polymorphism of the AT III gene using umbilical blood, and succeeded in diagnosing the neonatal child as AT III deficiency.     

Isolation and characterization of an acquired antithrombin antibody

A 68-year-old man, following mitral valve replacement, presented with a low-grade chronic consumptive coagulopathy. Laboratory analysis showed mild fibrinolysis, minimal effect of coumadin therapy, and a prolonged thrombin time (greater than 150 seconds using bovine IIa). When purified human IIa was used the thrombin time normalized to within 17 seconds of controls, suggesting a possible inhibitor of bovine IIa. An anti-IIa antibody was isolated by protein A-Sepharose (Sigma, St Louis, MO) chromatography followed by affinity chromatography using a bovine IIa-Sepharose column. The effects of this purified anti-IIa antibody on both bovine and human IIa procoagulant and anticoagulant functions were studied. The isolated immunoglobulin G (IgG) was observed to inhibit bovine IIa in all assays tested. This IgG was also able to slightly prolong fibrinogen clotting by human IIa. Using an enzyme-linked immunosorbent assay it was observed that the IgG bound to bovine IIa, bovine II, human IIa, but not to human II. Further, binding was detectable at approximately 50-fold lower concentrations to bovine IIa (1 nmol/L IgG concentration) than to human IIa (50 nmol/L IgG concentration). The effect of the antibody on the reaction between IIa and AT III/heparin was investigated. Human IIa was found to be protected from AT III/heparin neutralization in the presence of this antibody. These results suggest that this patient developed an antibody that strongly binds to and inhibits the bovine IIa in all assays tested. However, the antibody only significantly affects human IIa neutralization by AT III/heparin, and has little effect on the human IIa procoagulant activity. These data suggest that the decreased effect of AT III/heparin on this patient's IIa may have been a contributing factor in his coagulopathy. The exact cause of this antibody development is unclear, but the role of bovine topical thrombin used during cardiac valve replacement surgery is suspect.     

Acquired antithrombin III deficiency in patients with glomerular proteinuria

Antithrombin III (AT II/III) was determined immunologically and by means of a heparin cofactor assay in plasma samples and 24-hour urine of 15 patients with various degrees of proteinuria, being predominantly of glomerular origin. In urine the AT II/III concentrations were significantly correlated to the concentrations of albumin, plasminogen and IgG. One third of the patients had AT II/III plasma levels below the normal range. The plasma levels showed a significant inverse correlation to the AT II/III and albumin clearance rates. Similarily, the plasminogen concentrations in plasma were decreased in two thirds of the patients, being inversely correlated to the renal plasminogen clearance values. It is proposed that AT II/III deficiency in the nephrotic syndrome is an important pathogenetic factor in venous thrombosis.     

Clinical and biochemical characterization of antithrombin III Franconville, a variant with Pro 41 Leu mutation

We describe a familial study of AT III, a type III antithrombin III variant which was identified in the propositus by gene analysis as Pro 41 Leu heterozygous mutation. None of the four members of the family who presented with defective heparin cofactor (hep-cofactor) activity, and therefore probably carried the mutation, had experienced deep venous thrombosis. The abnormal AT III was purified from the propositus' plasma, taking advantage of the difference in NaCl concentrations required to elute variant and normal AT III from heparin-Sepharose. The antithrombin and anti-Xa activities of the purified variant AT III were comparable to those observed for normal AT III, but hep-cofactor activity was strikingly reduced. The enhancement by heparin of thrombin and F Xa inhibition by normal and variant AT III was compared in the absence of NaCl and in the presence of normal NaCl concentrations. The difference between the degrees of inhibition by normal and variant AT III was maximal at physiological ionic strength (i.e. at a concentration of 0.15 M). The quantification of heparin AT III interaction with both normal and variant purified proteins in a double reciprocal plot yielded similar dissociation constants but a 9-fold decrease in the maximal pseudo-first order constant. This suggests that Pro 41 is more involved in the molecular changes induced by heparin than in the primary binding of the activator.     

Choice of anticoagulant in a congenital antithrombin III (AT III)-deficient patient with chronic renal failure undergoing regular haemodialysis

Summary We describe a 43-year-old male patient with congenital antithrombin III deficiency requiring haemodialysis due to extension of venous thrombus from recurrent deep vein thrombosis. During dialysis with adequate heparinization, the patient often revealed clot formation in the extracorporeal circuit resulting in unexpected discontinuation of dialysis. When either a combination of antithrombin III concentrate plus heparin or the newly developed synthetic antithrombin preparation, MD805, was infused during dialysis, he could be uneventfully dialysed with either of the two regimens. The functional antithrombin III activity with MD805 increased to the same level as that obtained with antithrombin III concentrate, and it was possible to achieve an antithrombotic effect, as measured from the APTT and thrombin-antithrombin III complex with MD805 during and after dialysis. We thus found that MD805 could be used as an anticoagulant drug when an AT III-deficient patient required anticoagulation in the extracorporeal circulation.     

Hereditary and acquired antithrombin deficiency.

Antithrombin (AT) is the most important inhibitor of activated coagulation enzymes. Deficiency of this protein can be a congenital defect. Different types have been described with a diminution of the entire molecule as well as diminution of activity only with normal concentration and normal activity and concentration but with a decreased sensitivity to heparin. There exist also different types of acquired deficiency due to a diminished production, an increased loss or an increased consumption of the inhibitor. Because AT deficiency is the cause of an increased thrombotic tendency in many cases the therapeutic and prophylactic possibilities are described. Since highly purified concentrates became available, substitution was attempted in cases of AT deficiency. It was found to be of greatest importance in cases of disseminated intravascular coagulation (DIC) which is a frequent consequence of septic or traumatic shock. In such cases an adequate AT-substitution can even be lifesaving as could be shown in different trials.