Partial Characterization Of An Igm Ciroiating Anticqagu- Lant In A Patient With Systemic Scleroderma

1981 ◽  
Author(s):  
J Hauert ◽  
A von Felten
Keyword(s):  
Anticoagulant Activity ◽  
Time Factors ◽  
Human Platelets ◽  
Systemic Scleroderma ◽  
Fibrinogen Concentration ◽  
Spontaneous Bleeding ◽  
Coagulation Tests ◽  
Bleeding Manifestation ◽  
Tissue Thromboplastin ◽  
Partial Neutralization

All coagulation tests, utilizing phospholipids, were found to be prolonged in the plasma of a 71 year old wcman with systemic scleroderma. Hie patient had no spontaneous bleeding manifestations and underwent eye surgery for cataract without complications. Thrcmbin time and fibrinogen concentration were normal. Coagulation tests, performed with partial thromboplastin (APTT, factors VIII-XII), were more prolonged than those done with regular tissue thromboplastin (one-stage prothrombin time, factors II, V, VII, X). The addition of 1 part of the patient’s plasma (PP) to 99 parts of normal plasma (NP) resulted in a prolongation of the APTT from 34" to 49". No decrease of the anticoagulant activity (AA) was observed when freshly prepared intact platelets were incubated with the PP. However, incubation of PP with platelets, which had been 5 × frozen and thawed or incubated for 90 min in the presence of kaolin, partially neutralized AA.When the patient’s serum was fractionated on Bio-Gel A-5m, all the inhibitory activity was found in the IgM peak. The AA of the purified IgM fraction was quenched after incubation with an anti-IgM antiserum, but not with anti-IgA or anti-IgG. Incubation of the IgM fraction with stored washed human platelets also led to partial neutralization of the AA. The patient’s IgM adsorbed to lysophosphatidylserine, which had been coupled to octyl-Sepharose, but did not fix complement when incubated with phospholipid micelles consisting of phosphatidylserine-phosphatidylcholine (1:1) and cholesterol in excess.The absence of any bleeding manifestation in this patient; despite the presence of an extremely potent inhibitor against phospholipids, may be explained by the nonreactivity of the IgM inhibitor with fresh intact platelets.

Detection and Quantitative Evaluation of Lupus Circulating Anticoagulant Activity

1987 ◽  
Vol 57 (02) ◽  
pp. 144-147 ◽  
Author(s):  
Esther Rosner ◽  
Rachel Pauzner ◽  
Ayala Lusky ◽  
Michaela Modan ◽  
Amira Many
Keyword(s):  
Quantitative Evaluation ◽  
Anticoagulant Activity ◽  
Clotting Time ◽  
False Negatives ◽  
Coagulation Tests ◽  
Recurrent Abortions ◽  
Tissue Thromboplastin ◽  
Kaolin Clotting Time ◽  
Recalcification Time ◽  
Numerical Index

SummarySixty-six SLE patients were studied for the presence of lupus type circulating anticoagulant. Forty-nine percent of them showed activity of this anticoagulant. The sensitivity of various coagulation tests was compared. Recalcification time was found to be the most sensitive screening test and the kaolin clotting time mixture test, the best for determining the presence of the anticoagulant.Tissue thromboplastin inhibition test detected only half of the patients in whom the anticoagulant was found by recalcification time and kaolin clotting time mixture test.APTT, using 2 different reagents, resulted in 73% and 52% false negatives. A numerical index for determining the presence of the anticoagulant and its quantitative evaluation is suggested.The association between thromboembolic events, recurrent abortions and the different coagulation tests is shown.

Adenosine Diphosphate-Induced Aggregation of Human Platelets in Flow Through Tubes: III. Shear and Extrinsic Fibrinogen-Dependent Effects

1994 ◽  
Vol 71 (01) ◽  
pp. 078-090 ◽  
Author(s):  
H L Goldsmith ◽  
M M Frojmovic ◽  
Susan Braovac ◽  
Fiona McIntosh ◽  
T Wong
Keyword(s):  
Shear Rate ◽  
Single Cells ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
Size Analysis ◽  
Fibrinogen Concentration ◽  
Human Fibrinogen ◽  
Shear Rates ◽  
Rate Dependent ◽  
Induced Aggregation

SummaryThe effect of shear rate and fibrinogen concentration on adenosine diphosphate-induced aggregation of suspensions of washed human platelets in Poiseuille flow at 23°C was studied using a previously described double infusion technique and resistive particle counter size analysis (1). Using suspensions of multiple-centrifuged and -washed cells in Tyrodes-albumin [3 × 105 μl−1; (17)] with [fibrinogen] from 0 to 1.2μM, the, rate and extent of aggregation with 0.7 μM ADP in Tyrodes-albumin were measured over a range of mean transit times from 0.2 to 43 s, and at mean tube shear rates, Ḡ, = 41.9, 335 and 1,335 s−1. As measured by the decrease in singlet concentration, aggregation at 1.2 μM fibrinogen increased with increasing Ḡ up to 1,335 s1, in contrast to that previously reported in citratcd plasma, in which aggregation reached a maximum at Ḡ = 335 s−1. Without added fibrinogen, there was no aggregation at Ḡ = 41.9 s1; at Ḡ = 335 s1, there was significant aggregation but with an initial lag time, aggregation increasing further at Ḡ = 1,335 s−1. Without added fibrinogen, aggregation was abolished at all Ḡ upon incubation with the hexapeptide GRGDSP, but was almost unaffected by addition of an F(ab’)2 fragment of an antibody to human fibrinogen. Aggregation in the absence of added fibrinogen was also observed at 37°C. The activation of the multiple-washed platelets was tested using flow cytometry with the fluorescently labelled monoclonal antibodies FITC-PAC1 and FITC-9F9. It was shown that 57% of single cells in unactivated PRT expressed maximal GPIIb-IIIa fibrinogen receptors (MoAb PAC1) and 54% expressed pre-bound fibrinogen (MoAb 9F9), with further increases on ADP activation. However, incubation with GRGDSP and the F(ab’)2 fragment did not inhibit the prebound fibrinogen. Moreover, relatively unactivated cells (8% expressing receptor, 14% prebound fibrinogen), prepared from acidified cPRP by single centrifugation with 50 nM of the stable prostacyclin derivative, ZK 36 374, and resuspension in Tyrodes-albumin at 5 × 104 μl−1, aggregated with 2 and 5 μM ADP at Ḡ = 335 and 1,335 s−1 in the absence of added fibrinogen. We therefore postulate that a protein such as von Willebrand factor, secreted during platelet isolation or in flow at sufficiently high shear rates, may yield the observed shear-rate dependent aggregation without fibrinogen.

Relative Sensitivity of Different Tests in the Detection of Low Titer Lupus Anticoagulants

1988 ◽  
Vol 60 (02) ◽  
pp. 217-219 ◽  
Author(s):  
B Lesperance ◽  
M David ◽  
J Rauch ◽  
C Infante-Rivard ◽  
G E Rivard
Keyword(s):  
Relative Sensitivity ◽  
Fetal Outcome ◽  
Anticardiolipin Antibodies ◽  
Lupus Anticoagulants ◽  
Normal Plasma ◽  
Coagulation Tests ◽  
High Dilutions ◽  
Tissue Thromboplastin ◽  
High Concentrations ◽  
Kaolin Clotting Time

SummaryLupus anticoagulants (LA) and anticardiolipin antibodies have been strongly associated with recurrent abortion and fetal death. Because steroids have been reported to improve the fetal outcome of LA associated pregnancies, presumably by decreasing the levels of LA, it becomes desirable to have a simple and reliable test to monitor the levels of the putative antibody. To this effect, we assessed the capacity of the following coagulation tests to detect the presence of LA in serial dilutions of patient plasma with pooled normal plasma: kaolin clotting time (KCT), tissue thromboplastin inhibition test (TTIT), dilute Russell Viper venom time (DRVVT) and activated partial thromboplastin time with standard and high concentrations of phospholipids (SC and HCAPTT). All samples were also evaluated for the presence of anticardiolipin antibodies with an ELISA. The KCT was able to detect LA at a much greater dilution in normal plasma than any of the other clotting assays. The ELISA was comparable to KCT in its ability to detect high dilutions of LA.

dRVVT Is more Sensitive than KCT or TTI for Detecting Lupus Anticoagulant Activity of Anti-β2-glycoprotein I Autoantibodies

1999 ◽  
Vol 81 (02) ◽  
pp. 256-258 ◽  
Author(s):  
A. Biasiolo ◽  
P. Rampazzo ◽  
T. Brocco ◽  
V. Pengo
Keyword(s):  
Lupus Anticoagulant ◽  
Anticoagulant Activity ◽  
Test System ◽  
Clotting Time ◽  
Lupus Anticoagulants ◽  
Glycoprotein I ◽  
Tissue Thromboplastin ◽  
The Mean ◽  
Kaolin Clotting Time ◽  
Antibody Preparations

SummaryAnti-β2-glycoprotein I (β2-GPI) antibodies behave as classical Lupus Anticoagulants (LA), as they inhibit phospholipid-dependent coagulation reactions and their activity disappears in the presence of excess exogenous phospholipids (PLs). We have recently shown that a certain amount of PLs in the dilute Russell Viper Venom Time (dRVVT) test system is required to express LA activity of anti β2-GPI antibodies. We have now extended this observation to two other tests, i.e., Kaolin Clotting Time (KCT) in which PLs are not added, and Tissue Thromboplastin Inhibition test (TTI) in which PLs are extremely diluted. In fact, affinity-purified antibody preparations from 5 patients with antiphospholipid syndrome did not express or only weakly expressed anticoagulant activity in both tests; the mean ratios of coagulation times obtained with purified antibodies and that of control buffer were 1.11 and 1.0 for KCT and TTI, respectively. On the contrary, the mean ratios in dRVVT were 1.31 and 1.49 at a PLs dilution of 1:8 and 1:64, respectively. Therefore, the presence of LA activity due to autoantibodies to β2-GPI is characterized by a positive dRVVT and negative or only weakly positive KCT and TTI.

Combined blockade of thrombin anion binding exosite-1 and PAR4 produces synergistic antiplatelet effect in human platelets

2011 ◽  
Vol 105 (01) ◽  
pp. 88-95 ◽  
Author(s):  
Wei-Ya Wang ◽  
Chien-Kei Wei ◽  
Che-Ming Teng ◽  
Chin-Chung Wu
Keyword(s):  
Platelet Aggregation ◽  
Active Site ◽  
Antithrombotic Therapy ◽  
Specific Binding ◽  
Anticoagulant Activity ◽  
Human Platelets ◽  
Anion Binding ◽  
Inhibitory Effects ◽  
Clotting Time ◽  
Potential Strategy

SummaryThrombin exosite-1 mediates the specific binding of thrombin with fibrinogen and protease-activated receptor (PAR) 1. Exosite-1 inhibitors have been shown to effectively decrease the clotting activity of thrombin, while their antiplatelet effects are relatively weak. In the present study, the inhibitory effects of two exosite-1 inhibitors, hirugen and HD1, but not the exosite-2 inhibitor HD22, on thrombin-induced platelet aggregation and P-selectin expression were dramatically enhanced by a PAR4 antagonist, YD-3. In contrast, the PAR1 antagonist SCH-79797 did not affect the antiplatelet effects of exosite-1 inhibitors. The exosite-1 inhibitors and YD-3 prevented the Ca2+ spike and the prolonged Ca2+ response in thrombin-stimulated platelets, respectively; and combination of these two classes of agents led to abolishment of Ca2+ signal. Unlike exosite-1 inhibitors, the antiplatelet effects of the active site inhibitor PPACK and the bivalent inhibitor bivalirudin were not significantly enhanced by YD-3. In addition, the platelet-stimulating activity of γ-thrombin, an autolytic product of α-thrombin which lacks exosite-1, was inhibited by YD-3. These results suggest that the synergistic antiplatelet effects of exosite-1 inhibitor and PAR4 antagonist are resulted from combined blockade of PAR1 and PAR4 in platelets. In fibrinogen or plasma clotting assay, YD-3 neither prolonged the clotting time on its own nor enhanced the anticoagulant activity of exosite-1 inhibitors. Therefore, the combined blockade of exosite-1 and PAR4 may offer a potential strategy for improving the balance of benefits and risks of antithrombotic therapy.

LUPUS ANTICOAGULANT (LA) COEXISTENT WITH TRANSIENT PROTHROMBIN (FII) INHIBITOR: FTI DEFICIENCY DUE TO CLEARANCE OF THE B/MUNOCOMPLEX

1987 ◽  
Author(s):  
R Redaelli ◽  
F Baudo ◽  
B Busnach ◽  
T M Caimi ◽  
L Perrino ◽  
...  
Keyword(s):  
Survival Time ◽  
Replacement Therapy ◽  
Lupus Anticoagulant ◽  
Normal Tissue ◽  
Past History ◽  
Laboratory Data ◽  
Coagulation Factors ◽  
Precipitin Line ◽  
Coagulation Tests ◽  
Tissue Thromboplastin

23 y.o. man with acute nephritis and bleeding (epistaxis, ecchymosis) at presen-taticn. Family and personal past history negative for bleeding. Laboratory data consistent with SLE. Coagulation tests: FT Ratio (R) 1.8, aPTT R 2.4, FII:C <1%, FIIR:Ag 996, other coagulation factors normal. Tissue thromboplastin inhibition test (TTIT) R 2.8, congenital FII deficiency (696) R 1.6.1. FII survival time (Fll-ccncentrate infusion - 60 U/kg) t1/2: 9 hours.2. FII neutralizing activity (FTI:C normal plasma (NP) + buffer 5996; NP + patient plasna {PtP) 5096): absent.3. Irmunoccrplex formaticn4. FII inhibitor characterization (purified FII coupled to CNBr-activatedSepharose →PtP incubation with Fll-Sepharose→specific antiFII irrrrunoglobulins (Ig)* elution at acid pH→identification by double iimunodifftision): precipitin line with anti IgA, anti IgG2, anti k, anti 1.5. LA characterization (after FII inhibitor disappearance): TTTT on mixtures NP + PtP or N Ig in equal volumes.Diagnosis: SIE, LA (IgG); polyclonal (IgA, IgG2, k, 1) not neutralizing FII inhibitor; hypoprothrxmbinemia due to clearance of the irrrrunocorrplex.FII inhibitor was transient. Bleeding was rapidly controlled by replacement therapy. LA persits after FII inhibitor disappearance.

A Novel Congenital Bleeding Disorder Related to High Plasma Heparin-Like Anticoagulant Activity.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4074-4074
Author(s):  
Zhaoyue Wang ◽  
Haiyen Yang ◽  
Xia Bai ◽  
Wei Zhang ◽  
Changgeng Ruan
Keyword(s):  
Ex Vivo ◽  
Anticoagulant Activity ◽  
Coagulation Factors ◽  
High Plasma ◽  
Bleeding Disorder ◽  
Normal Plasma ◽  
Normal Ranges ◽  
Coagulation Tests ◽  
Plasma Heparin

Abstract Heparin or heparin-like compounds present in human plasma in minute amounts. It has been reported that a very few patients with such diseases as plasma cell neoplasms, acute monoblastic leukemia and acquired immune deficincy syndrome have an increased plasma heparin-like anticoagulant activity. Recently, we found a 10-year-old girl who was physically and developmentally normal, but had recurrent episodes of prolonged bleeding and hematoma starting in her early childhood, which could be stopped by transfusion of fresh frozen plasma or prothrombin complex concentrate. The coagulation tests of her plasma were regularly repeated since she was 2 years old, and always revealed a markedly prolonged APTT (61.8–104 seconds, normal 28–40 seconds) and TT (36–50.1 seconds, normal 14–21 seconds), and a slightly prolonged PT (15.9–25 seconds, normal 11–14.5 seconds). Fibrinogen, prothrombin and other coagulation factors as well as anticoagulant and fibrinolytic systems were all normal. The results of immunologic measurements were either negative or within normal ranges. Treatment of the patient’s plasma in vitro with either protamine or heparinase could completely normalize the coagulation abnormalities, but not with normal plasma. The anticoagulant activity of her plasma corresponded to 0.2 heparin U/mL when measured by a TT assay using normal plasma as substrate and standardized with porcine heparin. Her plasma heparin concentration was 0.22 heparin U/mL when measured using a colometric assay. In ex vivo study, the abnormal coagulation tests could effectively be corrected when the patient was intravenously administed with protamine. Considering these characteristic laboratory features of the patient, we suppose it would probably represent a novel congenital bleeding disorder related to high plasma heparin-like anticoagulant activity which, to our knowledge, had not been described before.

scholarly journals Comparison of anticoagulant and procoagulant activities of stimulated platelets and platelet-derived microparticles

Blood ◽  
1991 ◽  
Vol 77 (12) ◽  
pp. 2641-2648 ◽  
Author(s):  
G Tans ◽  
J Rosing ◽  
MC Thomassen ◽  
MJ Heeb ◽  
RF Zwaal ◽  
...  
Keyword(s):  
Anticoagulant Activity ◽  
Activated Protein C ◽  
Protein S ◽  
Adenosine Diphosphate ◽  
Order Rate Constant ◽  
Human Platelets ◽  
Ionophore A23187 ◽  
Similar Distribution ◽  
Reaction Conditions ◽  
Factor Va

Activation of human platelets considerably enhanced their ability to accelerate factor Va inactivation by activated protein C (APC). The anticoagulant activity of platelet suspensions was markedly dependent on the kind of agonist used to activate platelets. APC-catalyzed factor Va inactivation in free solution was characterized by an apparent second-order rate constant of 2 x 10(5) (mol/L)-1 (seconds)-1. Nonstimulated platelets (2.4 x 10(8)/mL) and platelets stimulated with adenosine diphosphate or adrenalin accelerated factor Va inactivation fourfold. Rates of factor Va inactivation were increased 11-fold by thrombin-stimulated platelets, 29-fold after platelet stimulation with the Ca(2+)-ionophore A23187. At low platelet concentrations (3 x 10(7)/mL) only background levels of anticoagulant activity were observed in platelet suspensions that were nonstimulated or stimulated with thrombin or collagen. However, when such reaction mixtures were stirred during the activation procedure, platelet anticoagulant activity was increased more than 10-fold. Independent of platelet stimulation and stirring conditions, exogenously added purified plasma protein S increased platelet-dependent factor Va inactivation approximately twofold. Addition of a neutralizing antiprotein S antibody had little effect on the anticoagulant activity of platelets. This indicates that, under the reaction conditions tested, platelet- released protein S did not contribute to factor Va inactivation. Approximately 25% of the anticoagulant activity of stimulated platelet suspensions appeared to be associated with microparticles that were released on platelet activation. Such microparticles may provide an important source of anticoagulant activity. A similar distribution of procoagulant, ie, prothrombinase, activity between platelets and microparticles was observed for the same platelet suspensions. Because platelet stimulation and stirring also had the same overall effects on the ability of platelets and platelet microparticles to promote prothrombin activation and factor Va inactivation, it appears likely that the generation of potential platelet anticoagulant and procoagulant activities is coupled to the same platelet stimulation reactions.

scholarly journals Correlation between fibrinogen binding to human platelets and platelet aggregability

Blood ◽  
1980 ◽  
Vol 55 (5) ◽  
pp. 841-847 ◽  
Author(s):  
EI Peerschke ◽  
MB Zucker ◽  
RA Grant ◽  
JJ Egan ◽  
MM Johnson
Keyword(s):  
Adenosine Diphosphate ◽  
Human Platelets ◽  
Fibrinogen Concentration ◽  
Platelet Aggregability ◽  
Single Receptor ◽  
Fibrinogen Binding ◽  
Fibrinogen Molecule ◽  
Bernard Soulier Syndrome

Fibrinogen is essential for aggregating platelets with adenosine diphosphate (ADP) and was recently shown to bind to platelets stimulated with ADP. The present work confirms the specific and saturable nature of the platelet-fibrinogen interaction. Binding of 125iodine-labeled fibrinogen to human gel-filtered platelts was maximal at 1 min, and the receptors were saturated when the fibrinogen concentration in the suspending medium approached 0.8 mg/ml. Assuming that one fibrinogen molecule interacts with a single receptor, experiments with 9 normal donors revealed the presence of 12,896 +/- 2456 receptors per platelet. Much of the bound material dissociated from platelets after incubation with apyrase or EDTA. Binding was markedly inhibited at pH 6.5, in the presence of EDTA, and with platelets from 3 thrombasthenic patients but not with those from a patient with the Bernard-Soulier syndrome. Fibrinogen binding was also virtually absent with platelets that had been incubated with EDTA for 8 min at 37 degrees C and pH 7.8. These platelets could not aggregate when mixed with ADP and adequate CaCl2 and fibrinogen, although they could still change their shape. Thus, ADP-induced binding of fibrinogen correlates with platelet aggregability.

scholarly journals Some normal value of coagulation tests, proteins concentration tests, iron concentration and copper concentration tests of local house cats in Baghdad city

2012 ◽  
Vol 36 (0A) ◽  
pp. 86-91
Author(s):  
Saleem Amin Hasso
Keyword(s):  
Prothrombin Time ◽  
Protein Concentration ◽  
Copper Concentration ◽  
Iron Concentration ◽  
Fibrinogen Concentration ◽  
Clotting Time ◽  
Total Protein Concentration ◽  
Blood Samples ◽  
Male And Female ◽  
Coagulation Tests

Forty seven blood samples were collected from local house cats 25 male , 22 female , ranging in age from 1-15 year for both sexes for measuring the following parameters coagulation tests (total Platelets count, Clotting time, Prothrombin Time & Fibrinogen concentration ) and proteins concentration tests (Total protein concentration, Albumin , Globulin concentration ) and iron and copper concentration tests .the results as were follow (228.5 –1,537) X 109\L , (2-5)min , (6 - 15) sec , (0.5 -4) g\L , ( 61 - 83 ) g\L , (23.1 -38.2) g\L , (25.9-54.2) g\L , (5.21 – 45.56) μmol/L , (2.29 - 36.52) μmol/L) .the result showed significant differences at level (P<0.05) between the male and female of local house cats in total Platelets count and Prothrombin Time . Other studied parameters showed no significant differences at level (P<0.05) between the male and female in local house cats.

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