Respective Roles of Antithrombin III and Alpha 2 Macroglobulin in Thrombin Inactivation

1981 ◽  
Vol 45 (01) ◽  
pp. 051-054 ◽  
Author(s):  
A M Fischer ◽  
J Tapon-Bretaudiere ◽  
A Bros ◽  
F Josso

SummaryIn order to investigate the mechanism of thrombin inactivation in the presence of both antithrombin III (AT III) and α 2-macroglobulin (α 2 M), thrombin and the inhibitors have been purified from human material and thrombin inactivation studied using purified reagents either alone or added to defibrinated plasma. Comparison of clotting and amidolytic activities of residual thrombin allowed to measure the amount of thrombin bound to α 2 M. In a purified reagent system as well as in plasma, part of exogenous thrombin is bound to α 2 M. The amount of bound thrombin is related to α 2 M concentration. Conversely, previous plasma α 2 M depletion by immunoabsorption increases the consumption of heparin-cofactor activity by exogenous thrombin. Thus AT III and α 2 M compete for thrombin inactivation. This finding could be of practical interest in clinical situations associating high plasma α 2 M levels and a decrease of AT III concentration.

1986 ◽  
Vol 55 (02) ◽  
pp. 218-221 ◽  
Author(s):  
A M Fischer ◽  
P Cornu ◽  
C Sternberg ◽  
F Mériane ◽  
M D Dautzenberg ◽  
...  

SummaryA qualitative abnormality of antithrombin III (AT III) was found in the plasma of a 41-year old patient. The plasmatic AT III antigen concentration was 130% and the progressive anti-F IIa and anti-F Xa activities were normal (105% and 137%). The plasma heparin cofactor activity was less than 10%, when measured by F Ila or F Xa inhibition. Crossed immunoelectrophoresis of AT III in the presence of heparin revealed in the plasma an abnormal slow-moving peak. When tested by affinity chromatography on heparin Sepharose, this abnormal AT III did not bind to heparin. Among the investigated relatives, 5 subjects had normal AT III levels, whatever the test used, the nine others having reduced levels of antithrombin heparin cofactor activity (45-61%) but normal levels of immunoreactive AT III (97-122%). Consanguinity was found in the family history. We therefore considered our patient as homozygous for an AT III molecular abnormality affecting the binding site for heparin.


1979 ◽  
Author(s):  
F. Panicucci ◽  
A. Sacripanti ◽  
E. Pinori ◽  
M. Vispi ◽  
B. Conte ◽  
...  

Determinations of AT-III activity, heparin cofactor activity, antifactor Xa activity and AT-III protein were carried out in 200 healthy adults, evenly distributed within age and sex groups, in 60 patients with cerebral thrombosis and in 20 oral contraceptive users. There was a positive correlation between AT-III protein and its activitiesin normal subjects and in patients with cerebral thrombosis. In oral contraceptive users the positive correlation was between AT-III protein and its activities, antifactor Xa activity excepted. The mean AT-III protein and heparin cofactor activity values decreased in males with age and were significantly lower in the groups between 50 and 70 years. The mean AT-III protein and heparin cofactor activity values decreased slightly in women in fertile age and were lower in the 40 to 50 age-group. The mean AT-III protein and its activities values did not show any variation in the patients with cerebral thrombosis. The mean antifactor Xa activity value in the women, taking the pill for 3 months, decreased, whereas the other AT-III activities and AT-III protein were unchanged.


1975 ◽  
Author(s):  
O. R. Ødegård ◽  
U. Abildgaard

Heparin cofactor activity and antithrombin III (At-III) activity measured with amidolytic methods; antifactor Xa by a clotting method (Biggs et al., Brit. J. Haemat. 19, 287, 1970) and immunoassay of At-III (Fagerhol & Abildgaard, Scand. J. Haemat. 7, 10, 1970) in plasma and serum showed:1) There was a close correlation between the plasma values as measured by all these methods (r = 0.84–0.93).2) The difference between plasma and serum values (“consumption”) was lower in warfarin treated and in haemophiliacs than in the other groups.3) The difference between plasma and serum was greater when measured by the heparin cofactor activity method than by the other methods. The reason for this discrepancy will be discussed. The results in different patient groups will be reported.4) As the heparin cofactor activity assay can be completed within 10 minutes after blood sampling, and has a higher precision than clotting assay and immuno assay, it is preferable for clinical use.


1985 ◽  
Vol 231 (1) ◽  
pp. 59-63 ◽  
Author(s):  
A M Jorgensen ◽  
C L Borders ◽  
W W Fish

A dilution/quench technique was used to monitor the time course of chemical modification on the heparin-cofactor (a) and progressive thrombin-inhibitory (b) activities of human antithrombin III. Treatment of antithrombin III (AT III) with 2,4,6-trinitrobenzenesulphonate at pH 8.3 and 25 degrees C leads to the loss of (a) at 60-fold more rapid rate than the loss of (b). This is consistent with previous reports [Rosenberg & Damus (1973) J. Biol. Chem. 248, 6490-6505; Pecon & Blackburn (1984) J. Biol. Chem. 259, 935-938] that lysine residues are involved in the binding of heparin to AT III, but not in thrombin binding. Treatment of AT III with phenylglyoxal at pH 8.3 and 25 degrees C again leads to a more rapid loss of (a) than of (b), with the loss of the former proceeding at a 4-fold faster rate. The presence of heparin during modification with phenylglyoxal significantly decreases the rate of loss of (a). Full loss of (a) correlates with the modification of seven arginine residues per inhibitor molecule, whereas loss of (b) does not commence until approximately four arginine residues are modified and is complete upon the modification of approximately eleven arginine residues per inhibitor molecule. This suggests that (the) arginine residue(s) in AT III are involved in the binding of heparin in addition to the known role of Arg-393 at the thrombin-recognition site [Rosenberg & Damus (1973) J. Biol. Chem. 248, 6490-6505; Jörnvall, Fish & Björk (1979) FEBS Lett. 106, 358-362].


1988 ◽  
Vol 59 (01) ◽  
pp. 013-017 ◽  
Author(s):  
E Grau ◽  
J Fontcuberta ◽  
J Félez ◽  
I de Diego ◽  
R Soto ◽  
...  

SummaryA quantitative and qualitative deficiency of antithrombin III (AT III) was found in four members of a Spanish family with thrombotic tendency. In all affected members, levels of AT III antigen and activity (heparin cofactor activity) were reduced to 50% of the normal range. When crossed immunoelectrophoresis (CIE) was performed in the presence of heparin, an abnormal slow-moving peak was found. Crossed immunoelectrofocusing (CIEF) from normal and affected individuals showed that normal AT III migrated between pH 4.9–5.3 while the AT III under study was asymetrically distributed between two pH ranges: 4.9–5.3 and 4.6–4.8. Affinity adsorption of affected members’ plasma to heparin-sepharose beads revealed one population of AT III in the supernatant corresponding to the abnormal AT III, devoid of heparin cofactor activity and showing a peak between pH range: 4.6–4.8 in CIEF.Our data supports the view that a quantitative-qualitative deficiency was present in the heterozygous state in all the affected family members. Both normal and abnormal ATIII were present in plasma of the affected individuals. This abnormal ATIII was characterized by a lack of affinity for heparin. This familial ATIII deficiency was named ATIII Barcelona.


1979 ◽  
Author(s):  
F. Panicucci ◽  
A. Sacrioanti ◽  
E. Pinori ◽  
M. Vispi ◽  
B. Conte ◽  
...  

Determinations of AT-III activity, heparin cofactor activity, antifactor Xa activity and AT-III protein were carried out in 200 healthy adults, evenly distributed within age and sex groups, in 60 patients with cerebral thrombosis and in 20 oral contraceptive users. There was a positive correlation between AT-III protein and its activities in normal subjects and in patients with cerebral thrombosis. in oral contraceptive users the positive correlation was between AT-III protein and its activities, antifactor Xa activity excepted. The mean AT-III protein and heparin cofactor activity values decreased in males with age and were significantly lower in the groups between 50 and 70 years. The mean AT-III protein and heparin cofactor activity values decreased slightly in women in fertile age and were lower in the 40 to 50 age-group. The mean AT-III protein and its activities values did not show any variation in the patients with cerebral thrombosis. The mean antifactor Xa activity value in the women, taking the pill for 3 months, decreased, whereas the other AT-III activities and AT-III protein were unchanged.


1987 ◽  
Author(s):  
Ph de Moerloose ◽  
G Reber ◽  
Ph Minazio ◽  
C A Bouvier

A 43-year old man presented a pulmonary embolism. Despite a negative family history for thromboembolic disorders, the unusual circumstances of apparition and the relatively young age of the patient prompted us to study carefully the coagulation parameters. Routine coagulation tests, as well as plasminogen, alpha-2-anti-plasmin, protein C and protein S were all within normal range. Biological and immunological assays of AT III were performed on 12 members of the family and showed a low AT III activity in the propositus and other members of this family (mean 50%), but normal immunologic levels. Crossed immunoelectrophoresis in absence of heparin showed a normal pattern, but in presence of heparin showed an abnormal peak as compared with controls. Kinetics experiments showed a normal inhibition of Xa and 11a in absence of heparin, but abnormal in presence of heparin. An affinity chromatography on heparin Sepharose revealed two populations of AT III, one of which was devoid of heparin cofactor activity.The toponym AT III Geneva is proposed for this new familial abnormal AT III with defective heparin cofactor activity. This family confirms the low incidence of thromboembolic events reported in this type of AT III variant.


1988 ◽  
Vol 60 (02) ◽  
pp. 137-140 ◽  
Author(s):  
E Grau ◽  
A Oliver ◽  
J Félez ◽  
P Barceló ◽  
C Fernandez ◽  
...  

SummaryHeparin cofactor II (HC II) levels were measured by electroimmunoassay in plasmas and urines from 68 patients with nephrotic syndrome. In addition, antithrombin III (AT III) and protein C (PC) activities and antigens were measured also in the same group of patients. Seven of these patients had histories of thrombosis. Plasma HC II levels (mean ± SD 105 ± 43) were not different from levels in healthy subjects (94 ± 17). Only 5 patients had low plasma levels of HC II. None of the patients with thrombosis had low HC II levels. Even though measurable amounts of HC II were found in 25 urines from 50 patients. There was a relationship in the urinary excretion between HC II and AT III and their urinary clearances were quite similar. However, no correlation was found between plasma HC II and AT III levels, and levels of AT III activity and antigen were significantly lower than in healthy subjects. Three patients with hystories of thrombosis had low AT III levels. Most patients (including those with thrombosis histories) had high plasma PC levels and increased urinary loss.It is suggested that HC II does not play an important role in the pathogenesis of thrombosis in nephrotic syndrome.


1986 ◽  
Vol 56 (01) ◽  
pp. 018-022 ◽  
Author(s):  
C Boyer ◽  
M Wolf ◽  
J Vedrenne ◽  
D Meyer ◽  
M J Larrieu

SummaryA qualitative defect of antithrombin III (AT III) was demonstrated in four members of a large Tunisian family by the discrepancy between a normal amount of antigen and decreased or absent heparin cofactor activity. The propositus, a 3-year-old girl, died from massive intracardiac thrombosis despite oral anticoagulant therapy. Heparin cofactor activity measured in the presence of thrombin or F. Xa was undetectable in her plasma. Anti-F. Xa activity was also absent when using low molecular weight heparin or a synthetic pentasaccharide, representing the binding site to AT III. The lack of affinity of the propositus AT III for heparin was demonstrated by two-dimensional immunoelectrophoresis and chromatography on heparin-Sepha-rose. The parents, first cousins, and the sister of the propositus also demonstrated a qualitative abnormality of AT III, with levels of heparin cofactor activity close to 50% of the normal range. Our data support the view that the abnormal protein was present at the heterozygous state in the parents and sister and at the homozygous state in the propositus. None of the affected family members had thrombotic episodes, except for the propositus. The name of AT III Fontainebleau is proposed for this variant.


1985 ◽  
Vol 53 (03) ◽  
pp. 314-319 ◽  
Author(s):  
D J Howarth ◽  
Diana Samson ◽  
Yvonne Stirling ◽  
M J Seghatchian

SummaryFurther studies have been carried out in a previously reported family with congenital antithrombin III (AT III) deficiency due to an abnormal variant of AT III (AT III Northwick Park). The variant has been identified in five members of the family, three of whom had a history of venous thrombosis. Inheritance followed an autosomal dominant pattern. The affected family members have reduced levels of antithrombin heparin cofactor (41–67%) and progressive antithrombin activity (44–62%) but normal levels of immunoreactive AT III (91–162%). Two dimensional immunoelectrophoresis (2 DIE) of AT III in the absence of heparin revealed an abnormal fast-moving peak in addition to the normal peak but 2 DIE in the presence of heparin appeared normal. Further studies confirmed that the abnormal AT III binds completely to heparin but has no heparin cofactor or progressive antithrombin activity. These results would be consistent with a mutation affecting the binding site for thrombin.


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