|
|||||||||
|
|
|
|
|
|
|
|
|
|
|
By
From the Department of Medicine, the Division of Hematology-Oncology, St Luke's-Roosevelt Hospital Center; and Columbia University College of Physicians and Surgeons, New York, NY.
The procoagulant activity of platelets induced by collagen, thrombin, and collagen plus thrombin, measured as their capacity to promote the conversion of prothrombin to thrombin in the presence of factors Va and Xa, was studied in patients with
THE FORMATION of platelet-fibrin thrombi at sites of vascular injury is the principal mechanism involved in both the arrest of bleeding and the formation of clinically important occlusive intravascular thrombi. The mechanisms by which platelets adhere to subendothelium and interact with platelet agonists such as collagen, thrombin, and adenosine diphosphate (ADP) to promote the formation of platelet aggregates at sites of injury have been reviewed.1,2 Central to the process of platelet aggregation is the formation of intercellular bridges between soluble ligands, principally fibrinogen and von Willebrand factor (vWF ), and platelet membrane glycoprotein (GP) IIb-IIIa.1,3,4 The transformation of GPIIb-IIIa to its high-affinity ligand binding state is the final common pathway by which all agonists act to initiate platelet aggregation.1,4,5
Activated platelets also contribute to fibrin formation by providing a catalytic membrane surface for assembling enzyme complexes involved in the sequential reactions leading to thrombin formation.6-9 In the tenase reaction, factor X is converted to factor Xa by a complex of factor VIIIa and factor IXa. The prothrombinase reaction catalyzes the conversion of prothrombin to thrombin by a complex of factor Va and factor Xa. In addition, platelets may also participate in the activation of the contact system.9
There is now considerable evidence that the transformation of the platelet plasma membrane into a procoagulant surface is caused by a progressive change in the composition of its lipid bilayer. Under normal conditions, the activity of an aminophospholipid translocase maintains phosphatidylserine primarily in the inner leaflet of the platelet membrane, while phosphatidylcholine is concentrated in the outer leaflet.6,8,10-12 This asymmetry can be abolished by physiologic agonists such as collagen and thrombin, and their mixture,6,8,11-14 presumably due to their ability to elevate intracellular calcium ([Ca2+]i ).15,16 This phospholipid "flip-flop" results in the exposure of phosphatidylserine on the outer layer of the membrane, producing a procoagulant surface6,8,11,14 that, in the presence of the coagulation factors involved in tenase and prothrombinase reactions, can increase the rate of thrombin formation by more than 1 million-fold.11,17 The mechanism by which an increase in [Ca2+]i promotes this flip-flop remains to be determined. Although the aminophospholipid translocase is inhibited by an increase in [Ca2+]i ,8,18,19 the rapid loss of phospholipid asymmetry is more likely caused by a separate Ca2+-dependent scrambling mechanism that increases the rate of both inward and outward movement of all phospholipids.8,20-22 Activation of this mechanism, which in both platelets and red blood cells (RBCs) may involve a protein ("scramblase"), appears to be reversible and dependent on a critical [Ca2+]i level.21,23,24 An abnormality in the translocation of phosphatidylserine to the platelet surface,25 associated with impaired prothrombinase25,26 and tenase25 activity, has been described in a patient with an isolated platelet coagulant defect and a moderately severe bleeding disorder (Scott syndrome).27,28 Another patient who may have the same type of defect has also been described recently.29
The relationship between the mechanisms involved in the transformation of GPIIb-IIIa to its high-affinity ligand-binding state and those responsible for the development of the platelet coagulant activity (PCA) is presently unclear. Early studies on patients with thrombasthenia30-35 who are deficient in GPIIb-IIIa36 reported abnormalities in PCA, designated as platelet factor 3 (PF3). These studies used a method in which PCA was induced by incubating platelet-rich plasma with kaolin and assessing the capacity of the activated platelets to shorten the recalcification or Russell's viper venom time of platelet-poor plasma. Impaired activation of the contact system was also reported.35 More recent studies have yielded conflicting results. The activated whole-blood clotting time was found to be prolonged in patients undergoing coronary angioplasty who received a monoclonal antibody (MoAb) to GPIIb-IIIa.37 However, Bevers et al38 reported normal prothrombinase activity in four patients with several types of thrombasthenia. Other studies reported that the absence39 or blockade40 of GPIIb-IIIa actually promoted fibrin formation on subendothelium39 and collagen,40 and in the early, but not the later, stages of hemostasis as measured in bleeding time wounds.41 A role for GPIIb-IIIa in promoting vesiculation of the platelet membrane, which has been linked in some studies13 to the development of prothrombinase activity, has also been proposed,42 but contrary evidence has been reported in other studies.43
The role of platelet secretion and/or granule-bound substances in promoting PCA is also not clear. Early studies reported impaired PF3 availability (PF3a) in patients with secretion defects,31 some of whom had storage pool deficiency (SPD),44 a platelet disorder characterized by reduced contents of substances stored in dense granules ( To examine these questions further, we have performed studies on agonist-induced platelet prothrombinase activity in 5 patients with thrombasthenia and 20 patients with various types of SPD ( Reagents
Collection of Blood and Preparation of Platelet-Rich Plasma (PRP)
Platelet Factor 3 Availability (PF3a) A previously described method was used to measure kaolin-induced PF-3a.27,31 In this test, 0.4 mL of PRP, adjusted with autologous platelet-poor plasma (PPP) to a platelet count of 300,000/µL, was incubated with 0.2 mL of 8% kaolin at 37°C for 6 minutes, after which time a 0.05-mL aliquot was transferred to a test tube containing 0.3 mL of normal substrate PPP that had been activated with 0.15 mL of 2% kaolin during the preceding 4 minutes. The clotting time was determined immediately by the addition of 0.4 mL of 0.025 mol/L calcium chloride (recalcification time). The average value in normal subjects (n = 30) was 43 seconds (±2 SD = 35 to 51).Platelet Factor V Coagulant Activity Platelet factor V coagulant activity was measured in Triton X-100 lysates of gel-filtered platelets (GFP) prepared by mixing 400 µL of GFP with 11.5 µL of 100 mmol/L Ca(NO3 )2 and 50 µL of 1.8% Triton X-100 (Sigma Chemical). Factor V activity in dilutions of these lysates was assessed with Thromboplastin.C Plus (Baxter Diagnostics, Inc) by a one-stage clotting assay using factor V-deficient human substrate plasma (Baxter). The average value in normal subjects (n = 15) was 68 U/1011 platelets (±2 SD = 31 to 105). The assay used measures the coagulant platelet factor V that is stored as a partially proteolyzed, active cofactor,47 as well as any factor V that is activated to Va by thrombin formed during the assay.Platelet vWF:Ag Platelet vWF:Ag in washed platelets was assayed by electroimmunoassay, as described previously.48 The average value in normal subjects (n = 31) was 43 U/1011 platelets (±2 SD = 20 to 66).Platelet  -TG was assayed in Triton X-100 lysates of GFP using an Asserchrom -TG ELISA kit (American Bioproducts Co, Parsippany, NJ). The average value in normal subjects (n = 7) was 4,499 ± 496 (SD) ng/108 platelets.
Platelet Prothrombinase Activity ACD PRP containing 1 µmol/L prostaglandin E1(PGE1 ) was gel-filtered into Ca-free Tyrode's elution buffer, pH 7.35, containing 5 mmol/L HEPES, 1 mmol/L Mg2+, 0.1% glucose, and 0.2% bovine albumin as described previously.49 Prothrombinase activity in GFP was assayed by a modification of the method of Weidmer et al.50 Because the activities generated in aggregated (stirred), as well as nonaggregated (unstirred) platelets were being measured, platelet activation and the prothrombinase assay were performed in the same cuvette to avoid a potentially irreproducible transfer of an aliquot of aggregated platelets. Duplicate samples consisting of 280 µL GFP, 7.5 µL 100 mmol/L Ca2+, 7.5 or 2.5 µL elution buffer, and 5 µL of agonist were activated with and without stirring in a Payton Dual Channel Aggregometer (Payton Associates, Buffalo, NY). The platelet (plt) concentrations of the GFP were adjusted for each agonist, as follows: unstimulated (saline): 1.4 × 108 plts/mL; collagen: 1.1 × 108 plts/mL; thrombin, collagen plus thrombin: 7 × 107 plts/mL. Unstirred samples were mixed briefly by hand every 2 minutes during the activation period (see below). Activation was for 10 minutes at 37°C using 10 µg/mL "Horm" collagen, 0.1 U/mL bovine thrombin, collagen plus thrombin, or saline. The extent of aggregation induced by thrombin in stirred normal GFP under these conditions was 53% ± 3% (n = 21), confirming the functional capacity of these platelets. After 9 minutes of activation, 50 µL each of 27 µmol/L prothrombin, 20 nmol/L factor Va, and 8 mmol/L Ca2+/6% albumin was added to each sample with brief mixing. The Ca2+/albumin was added to preserve the Ca2+ concentration at 2.5 mmol/L and raise the albumin concentration to 1%. In some studies factor Va was not added, and was therefore provided entirely by the activated platelets. At 10 minutes, the stir bar was removed from the stirred sample and 50 µL of 20 nmol/L factor Xa was added to each sample. After exactly 1 minute (for thrombin and collagen plus thrombin) or 3 minutes (for collagen), 50-µL aliquots were transferred into 450 µL of ice-cold stopping buffer consisting of 10 mmol/L TES, 10 mmol/L EDTA, 0.15 mol/L NaCl, and 1% bovine albumin, pH 7.5. A 3-minute assay time for the collagen-stimulated samples was used because in preliminary studies, the amounts of thrombin generated during the first minute of the prothrombinase assay were found to vary substantially.
Intracellular Ca2+ Mobilization Using Fura-2-Loaded Platelets Platelets were isolated from ACD PRP, loaded with fura-2/AM, and gel-filtered into Ca-free Tyrode's elution buffer as described previously.51 The increases in [Ca2+]i induced by collagen, thrombin, and collagen plus thrombin were measured at the same agonist concentrations, extracellular Ca2+ concentration (2.5 mmol/L), platelet concentrations, and activation times (10 minutes) as for the prothrombinase assay, in the presence and absence of stirring, according to the procedures described previously.51 The values of fura-2 fluorescence at 340 and 380 nm excitation were corrected for leakage of fura-2 using the changes in fluorescence at 340 nm produced by sequential additions of 100 µmol/L Mn2+ and 200 µmol/L DTPA-Ca2+ to estimate the amount of extracellular fura-2.52 It should be noted that, while most conditions in which [Ca2+]i changes were measured were identical to those in which prothrombinase activity was measured, the stirring speed and efficiency could not be made identical because of the mechanical differences in the instruments used.Patients Twenty-eight patients with functional platelet defects were studied, including 20 with storage pool deficiency (18 -SPD, 1  -SPD, 1 -SPD), 5 with Glanzmann's thrombasthenia, and 3 with an isolated defect in PF3a, including 2 previously unreported patients (MSn and MP). A patient with factor V deficiency, whose platelet defect is assumed to be a specific deficiency of -granule factor V, was also studied.
-SPD (Hermansky-Pudlak syndrome, HPS)45,46 were studied. All have longstanding bleeding problems of varying severity. Seven of these patients have been the subjects of previous reports45,54,55; four are new patients, two of whom are sisters with a longstanding history of colitis.
-granule constituents. Her platelets contain approximately 20% of the normal amount of -granule number and substances.45
-granules (gray platelet syndrome).57 Both vWF:Ag and fibrinogen are undetectable in her platelets. Platelet ATP, ADP, and serotonin values are normal. The platelet factor V value was 7 U/1011 platelets (10% normal).
Thrombasthenia Studies were performed on four previously described patients (MC, CG, LW, LM) whose platelet GPIIb-IIIa is markedly reduced41,58 and on one new patient (AE). The binding to their platelets of 7E3, an MoAb that reacts with both GPIIb-IIIa andv3 ,59 and 10E5, which reacts only with GPIIb-IIIa60 (kindly performed by Dr Barry S. Coller, Mt Sinai School of Medicine, New York, NY), was (% normal): LW 5.4, 2.6; MC 1.9, 11.4; CG 1.2, 3.4; AE 10.0, 9.0, and LM 5.8, 10.1. A GPIIb missense mutation (Leu 214 Pro) has recently been reported in patient LW.61 Patient AE is somewhat atypical in that his PRP aggregated to a small extent (5% to 13%) with 50 µmol/L ADP on five occasions whereas only a shape change was observed in the other four patients. This small amount of platelet aggregation was eliminated completely by addition to his PRP of MoAbs against GPIIb-IIIa (7E3 from Dr Coller and LJCP8 from Dr Zaverio M. Ruggeri, La Jolla, CA). The PF3a value on patient AE was 51 seconds whereas it was 58 to 65 seconds in the other patients.
Isolated Defects in Platelet Coagulant Activity Three patients with isolated PCA defects were studied, including the previously reported patient with Scott Syndrome28 and two more recently studied patients (MSn and MP).Scott Syndrome Patient MS is the originally reported patient who was found to have an isolated defect in PF3a.27 Subsequent studies showed that her activated platelets exhibited decreased numbers of newly exposed membrane binding sites for coagulation factors Va13,26 and VIIIa,62 reflecting a diminished surface exposure of phosphatidylserine,25 and resulting in reduced membrane catalytic activity for both the tenase25 and prothrombinase complexes.25,26 In addition, the capacity of her platelets to generate microparticles13 and support fibrin formation on subendothelium39 is reduced. The various platelet studies, as well as those demonstrating decreased procoagulant activity in her RBCs63 and lymphocytes,64 that have been performed on this patient have been summarized recently.28Patient MP MP is a 46-year-old woman who bled excessively after an appendectomy at age 16, a hemorrhoidectomy at age 22, cosmetic eye surgery at age 40, and after the birth of one of her two children. She does not bruise easily and did not bleed excessively at age 39 after extraction of a third molar tooth. There is no history of excessive bleeding in her parents, two children, or four siblings. Other medical conditions and diagnoses include fibromyalgia, herniated intervertebral disc, mitral valve prolapse, and a thyroid nodule, for which she has been taking Synthroid (Knoll Pharmaceuticals, Mount Olive, NJ). Normal values were obtained for the bleeding time, platelet count, activated partial thromboplastin time (APTT), prothrombin time, and plasma vWF:Ag (75%), factor VIII (132%), and factor V (80%). Platelet aggregation, adenine nucleotides, and serotonin were normal. Normal values were also obtained for platelet vWF:Ag (56 U/1011 platelets) and-thromboglobulin (4,303 ng/108 platelets); however, her average coagulant platelet factor V value (42 U/1011, 62% normal), measured on four occasions, was less than all but 1 of 15 normal subjects. Her PF3a value was 61 seconds when studied initially at age 41 (normal value < 51 seconds). The average of PF3a values obtained on eight separate occasions over a 4-year period was 57 seconds versus paired control values of 44 seconds. At age 46, she received 10 U of platelets before a total abdominal hysterectomy and bilateral salpingo-oophorectomy for intractable pelvic pain and menorrhagia associated with cystic hyperplasia and adenomyosis of the uterus. The surgery was uneventful and no postoperative transfusion was required.
Patient MSn MSn is a 60-year-old woman who has always bruised easily, has had epistaxis on many occasions, and bled excessively after a tonsillectomy at age 7, a rhinoplasty at age 19 (requiring rehospitalization and transfusions), a rectal polypectomy at age 31 (requiring blood transfusion), and a tooth extraction at age 53. Bleeding after superficial cuts is not prolonged, but rebleeding may occur several hours later. Her father and paternal grandmother were also said to have suffered from epistaxis. There is no history of excessive bleeding in her mother or her two brothers. She was initially studied in our laboratory at age 56, at which time she was taking Premarin (Wyeth-Ayerst Pharmaceuticals, Philadelphia, PA) and Provera (Pharmacia & Upjohn Co, Kalamazoo, MI), Lopressor (Ciba-Geigy, Summit, NJ) for hypertension, and Synthroid for an "underactive thyroid," diagnosed 13 years previously. Except for repeatedly abnormal PF3a values, all other tests (those described for patient MP) have been normal, including platelet vWF:Ag,-thromboglobulin, and coagulant factor V values (89%, 103%, and 92% of normal, respectively). When studied initially, her PF3a value was 69 seconds; repeat studies 3 months later confirmed these findings (PF3a = 71 seconds). In subsequent years, she received Tenormin (Zeneca Pharmaceuticals, Wilmington, DE) and Cardizem (Hoechst Marion Roussel, Kansas City, MO) on various occasions for treatment of hypertension, and she was begun on Prozac (Dista-Eli Lilly, Indianapolis, IN) at age 59. The average of PF3a values, obtained on seven separate occasions, was 61 seconds versus concurrent control values of 43 seconds. A breast biopsy at age 58 and a laparoscopic cholecystectomy at age 59, both performed with platelet coverage, were uncomplicated.
Factor V Deficiency A patient with congenital factor V deficiency was kindly made available by Dr Leonard Stutman (St Vincent's Hospital, New York, NY). The plasma factor V value was 14% and the platelet coagulant factor V was 8 U/1011 (12% normal).Control Subjects Control subjects were normal hospital personnel. Except where specifically indicated, all patients and controls had refrained from taking drugs for at least 7 days before study. All studies were performed under a protocol approved by the Institutional Review Board of the St Luke's-Roosevelt Institute for Health Sciences.Statistics Where studies on patients and controls were obtained on more than one occasion, the values were averaged. Comparisons of patient and control groups were determined by Student's t-test for either nonpaired or paired samples.
Platelet Prothrombinase and Other Coagulant Activities Table 1 summarizes the results obtained for PF3a, platelet coagulant factor V, and thrombin or collagen plus thrombin-induced prothrombinase activity in stirred GFP.
Normal Subjects Prothrombinase activity was observed in platelets stimulated with collagen (Table 2) or thrombin alone, and in combination (Table 1, Fig 1). Collagen plus thrombin-induced prothrombinase activity in the absence of added factor Va was 72% of that in the presence of added factor Va, indicating that a substantial portion of total prothrombinase activity could be supported by platelet-derived factor Va. Prothrombinase activity was also measured in the absence of stirring, to minimize any effects of platelet aggregation on prothrombinase generation. For all agonists tested, the values obtained in unstirred GFP were less than those in stirred GFP (Fig 1A through C).
Isolated Defects in PCA Patients in this group were found initially to have reduced PF3a, and all had reduced prothrombinase activity with one or more agonists.Dense Granule Defects Results are shown in Table 1 for patients with both the HPS and non-HPS variants of-SPD. The PF3a values in the HPS patients were, on average, only moderately abnormal. Among non-HPS patients, only patient ES and her daughter NS were abnormal.
and -SPD; factor V deficiency) was a variable reduction in platelet coagulant factor V and an impaired collagen plus thrombin-induced prothrombinase activity in the absence of added factor Va (Table 1). The addition of factor Va completely corrected the latter defect in the factor V-deficient patient, as reported previously,65 whereas only partial correction was achieved in the patient with -SPD, and no correction was achieved in the patient with -SPD.
Thrombasthenia The average prothrombinase activities in stirred GFP in the five patients did not differ significantly from those in controls (Table 1 and Fig 1A through C). However, considerable variation in the individual values obtained with both thrombin and collagen plus thrombin was observed among these patients (data not shown). The values for patient AE were notably increased, and if this somewhat atypical patient (see Materials and Methods) was eliminated from the analysis, the mean collagen plus thrombin-induced activity would have been significantly decreased in both stirred samples (1,409 ± 118 v 1,899 ± 113, P < .05; patient AE = 2,452) and unstirred samples (718 ± 126 v 1,036 ± 90, P = .05; patient AE = 1,618).
Platelet [Ca2+]i Responses Normal subjects. In both stirred and unstirred GFP, thrombin and collagen plus thrombin produced a rapid initial increase in [Ca2+]i to generally similar values (Fig 2). This was followed by a gradual decrease in unstirred samples and in stirred samples stimulated with thrombin, whereas a secondary increase in [Ca2+]i that was maintained throughout the activation period occurred in stirred GFP stimulated with collagen plus thrombin (Fig 2A). In contrast, collagen alone induced a delayed and slower increase in [Ca2+]i , which reached peak values of 307 ± 35 nmol/L with stirring and 86 ± 7 nmol/L without stirring. Figure 1D through F shows the average [Ca2+]i values, calculated as described in Materials and Methods, for the entire period of activation.
Previous reports of a patient (Scott syndrome) with an isolated defect of PF3a whose platelets do not generate the prothrombinase and tenase activities associated with normal platelet procoagulant activity, and in whom surgically related bleeding has been controlled by platelet transfusion,27,28 have provided evidence that these platelet procoagulant properties are essential for normal hemostasis. A second patient with an isolated prothrombinase defect has also been reported recently.29 In the present study, we have identified two new patients (MP and MSn) with relatively severe bleeding disorders in whom the only defects were impaired platelet PF3a and prothrombinase activities. Both patients had bled excessively after many surgical procedures, but with platelet coverage patient MP underwent an uncomplicated total abdominal hysterectomy and bilateral salpingo-oophorectomy, and patient MSn underwent an uncomplicated cholecystectomy. The clinical and laboratory findings in these patients therefore provide additional evidence that the expression of platelet prothrombinase activity is required for normal hemostasis.
Mary Ann Scott died on November 12, 1996 at the age of 57. It was only her longstanding and selfless cooperation that made possible the many studies on the disorder that bears her name. This work is dedicated to her memory.
Submitted July 8, 1996;
accepted October 16, 1996.
The publication costs of this article were defrayed in part by page
charge payment. This article must therefore be hearly marked
``advertisment'' in accordance with 18 U.S.C. section 1734 solely to
indicate this fact. The authors thank Helen Dahan, Diane Sardini, and John Rogers for expert technical assistance, and Drs N. Peter Zauber and David J. Wolf for referral of patients MP and MSn, respectively.
1. Ware JA, Coller BS: Platelet morphology, biochemistry and function, in Beutler E, Lichtman MA, Coller BS, Kipps TJ (eds): Williams Hematology (ed 5). New York, NY, McGraw-Hill, 1995, p 1161
2.
Weiss HJ:
Flow-related platelet deposition on subendothelium.
Thromb Haemost
74:117,
1995[Medline]
[Order article via Infotrieve]
3.
Ruggeri ZM:
New insights into the mechanisms of platelet adhesion and aggregation.
Semin Hematol
31:229,
1994[Medline]
[Order article via Infotrieve]
4. Hawiger J: Adhesive interactions of blood cells and the vascular wall, in Colman RW, Hirsh J, Marder V, Salzman EW (eds): Hemostasis and Thrombosis: Basic Principles and Clinical Practice (ed 3). Philadelphia, PA, Lippincott, 1994, p 762
5.
Shattil SJ:
Function and regulation of the
6.
Shroit AJ,
Zwaal RFA:
Transbilayer movement of phospholipids in red cell and platelet membranes.
Biochim Biophys Acta
1071:313,
1991[Medline]
[Order article via Infotrieve]
7.
Mann KG,
Krishnaswamy S,
Lawson JH:
Surface-dependent hemostasis.
Semin Hematol
29:213,
1992[Medline]
[Order article via Infotrieve]
8.
Zwaal RFA,
Comfurius P,
Bevers EM:
Platelet procoagulant activity and microvesicle formation. Its putative role in hemostasis and thrombosis.
Biochim Biophys Acta
1180:1,
1992[Medline]
[Order article via Infotrieve]
9. Walsh PN: Platelet-coagulant protein interactions, in Colman RW, Hirsh J, Marder VJ, Salzman EW (eds): Hemostasis and Thrombosis, Basic Principles and Clinical Practice (ed 3). Philadelphia, PA, Lippincott, p 629
10.
Seigneuret M,
Devaux PF:
ATP-dependent asymmetric distribution of spin-labeled phospholipids in the erythrocyte membrane: Relation to shape changes.
Proc Natl Acad Sci USA
81:3751,
1984
11. Bevers EM, Rosing J, Zwaal RFA: Platelets and coagulation, in MacIntyre DE, Gordon JL (eds): Platelets in Biology and Pathology, vol III. New York, NY, Elsevier Science, 1987, p 127
12.
Schick PK,
Kurica KB,
Chacko GK:
Location of phosphatidylethanolamine and phosphatidylserine in the human platelet plasma membrane.
J Clin Invest
57:1221,
1976
13.
Sims PJ,
Wiedmer T,
Esmon CT,
Weiss HJ,
Shattil SJ:
Assembly of the platelet prothrombinase complex is linked to vesiculation of the platelet plasma membrane. Studies in Scott syndrome: An isolated defect in platelet procoagulant activity.
J Biol Chem
264:17049,
1989
14.
Zwaal RFA,
Bevers EM,
Comfurius P,
Rosing J,
Tilly RHJ,
Verhallen PFJ:
Loss of membrane phospholipid asymmetry during activation of blood platelets and sickled red cells: Mechanisms and physiological significance.
Mol Cell Biochem
91:23,
1989[Medline]
[Order article via Infotrieve]
15. Sage SO, Sargeant P, Heemskerk JWM, Mahaut-Smith MP: Calcium influx mechanisms and signal organization in human platelets, in Authi KS, Watson SP, Kakkar VV (eds): Mechanisms of Platelet Activation and Control. New York, NY, Plenum, 1993, p 69
16.
Rink TJ,
Sage SO:
Calcium signaling in human platelets.
Annu Rev Physiol
52:431,
1990[Medline]
[Order article via Infotrieve]
17. Mann KG, Tracy PB, Kirshnaswamy S, Jenny RJ, Odegaard BH, Nesheim ME: Platelets and coagulation, in Verstrate M, Vermylen, Lijnen HR, Arnout J (eds): Thrombosis and Haemostasis. Leuven, Belgium, Leuven University, 1987, p 505
18.
Bitbol M,
Fellmann P,
Zachowski A,
Devaux PF:
Phosphatidylserine exposed by platelet microvesiculation.
Biochim Biophys Acta
904:268,
1987[Medline]
[Order article via Infotrieve]
19.
Comfurius P,
Senden JMG,
Tilly RHJ,
Schroit AJ,
Bevers EM,
Zwaal RFA:
Loss of membrane phospholipid asymmetry in platelets and red cells may be associated with calcium-induced shedding of plasma membrane and inhibition of aminophospholipid translocase.
Biochim Biophys Acta
1026:153,
1990[Medline]
[Order article via Infotrieve]
20.
Bevers EM,
Comfurius P,
van Rijn JLML,
Hemker HC,
Zwaal RFA:
Generation of prothrombin converting activity and the exposure of phosphatidylserine at the outer surface of platelets.
Eur J Biochem
122:429,
1982[Medline]
[Order article via Infotrieve]
21.
Williamson P,
Bevers EM,
Smeets EF,
Comfurius P,
Schlegel RA,
Zwaal RFA:
Continuous analysis of the mechanism of activated transbilayer lipid movement in platelets.
Biochemistry
34:10448,
1995[Medline]
[Order article via Infotrieve]
22.
Williamson P,
Kulick A,
Zachowski A,
Schlegel RA,
Devaux PF:
Ca2+ induces transbilayer redistribution of all major phospholipids in human erythrocytes.
Biochemistry
31:6355,
1992[Medline]
[Order article via Infotrieve]
23.
Comfurius P,
Williamson P,
Smeets EF,
Schlegel RA,
Bevers EM,
Zwall RFA:
Reconstitution of phospholipid scramblase activity from human blood platelets.
Biochemistry
35:7631,
1996[Medline]
[Order article via Infotrieve]
24.
Basse F,
Stout JG,
Sims PJ,
Wiedmer T:
Isolation of an erythrocyte membrane protein that mediates Ca2+-dependent transbilayer movement of phospholipid.
J Biol Chem
271:17205,
1996
25.
Rosing J,
Bevers EM,
Comfurius P,
Hemker HC,
von Dieijen G,
Weiss HJ,
Zwaal RFA:
Impaired factor X and prothrombin activation associated with decreased phospholipid exposure in platelets from a patient with a bleeding disorder.
Blood
65:1557,
1985
26.
Miletich JP,
Kane WH,
Hofmann SL,
Stanford N,
Majerus PW:
Deficiency of factor Xa -factor Va binding sites on the platelets of a patient with a bleeding disorder.
Blood
54:1015,
1979
27.
Weiss HJ,
Vicic WJ,
Lages BA,
Rogers J:
Isolated deficiency of platelet procoagulant activity.
Am J Med
67:206,
1979[Medline]
[Order article via Infotrieve]
28.
Weiss HJ:
Scott syndrome: A disorder of platelet coagulant activity (PCA).
Semin Hematol
31:312,
1994[Medline]
[Order article via Infotrieve]
29.
Toti F,
Satta N,
Fressinaud E,
Meyer D,
Freyssinet J-M:
Scott syndrome, characterized by impaired transmembrane migration of procoagulant phosphatidylserine and hemorrhagic complication, is an inherited disorder.
Blood
87:1409,
1996
30.
Hardisty RM,
Dormandy KM,
Hutton RA:
Thrombasthenia: Studies on three cases.
Br J Haematol
10:371,
1964[Medline]
[Order article via Infotrieve]
31.
Weiss HJ:
Platelet aggregation, adhesion and ADP release in thrombopathia (platelet factor 3 deficiency)
32.
Weiss HJ,
Kochwa S:
Studies of platelet function and proteins in three patients with Glanzmann's thrombasthenia.
J Lab Clin Med
71:153,
1968[Medline]
[Order article via Infotrieve]
33.
Caen JP,
Castaldi PA,
Leclerc JC:
Congenital bleeding disorders with long bleeding time and normal platelet count. I. Glanzmann's thrombasthenia.
Am J Med
41:4,
1966
34.
Zucker MB,
Pert JH,
Hilgartner MW:
Platelet function in a patient with thrombasthenia.
Blood
28:524,
1966
35.
Walsh PN:
Platelet coagulant activities in thrombasthenia.
Br J Haematol
23:533,
1972
36. Coller BS: Hereditary qualitative platelet disorders, in Beutler E, Lichtman MA, Coller BS, Kipps TJ (eds): Williams Hematology (ed 5). New York, NY, McGraw-Hill, 1995, p 1364
37.
Moliterno DJ,
Califf RM,
Aguirre FV,
Anderson K,
Sigmon KN,
Weisman HF,
Topol EJ,
for the EPIC Study Investigators:
Activated clotting time is increased during coronary interventions with platelet glycoprotein IIb/IIIa integrin blockade: Results from the EPIC trial.
Am J Cardiol
5:554,
1995
38.
Bevers EM,
Comfurius P,
Nieuwenhuis HK,
Levy-Toledano S,
Enouf J,
Belluci S,
Caen JP,
Zwaal RFA:
Platelet prothrombin converting activity in hereditary disorders of platelet function.
Br J Haematol
63:336,
1986
39.
Weiss HJ,
Turitto VT,
Baumgartner HR:
The role of shear rate and platelets in promoting fibrin formation on rabbit subendothelium: Studies utilizing patients with quantitative and qualitative platelet defects.
J Clin Invest
78:1072,
1986
40.
Kirchhofer D,
Tschopp TB,
Steiner B,
Baumgartner HR:
Role of collagen-adherent platelets in mediating fibrin formation in flowing whole blood.
Blood
86:3815,
1995
41.
Weiss HJ,
Lages B:
Studies of thromboxane B2 , platelet factor 4, and fibrinopeptide A in bleeding time blood of patients deficient in von Willebrand factor, platelet glycoproteins Ib, IIb-IIIa, and storage granules.
Blood
82:481,
1993
42.
Gemmell CH,
Sefton MV,
Yeo EL:
Platelet derived microparticle formation involves glycoprotein IIb/IIIa. Inhibition by RGDS and Glanzmann's thrombasthenia defect.
J Biol Chem
268:14586,
1993
43.
Dachary-Prigent J,
Freyssinet J-M,
Pasquet J-M,
Carron J-C,
Nurden AT:
Annexin V as a probe of aminophospholipid exposure and platelet membrane vesiculation: A flow cytometry study showing a role for free sulfhydryl groups.
Blood
81:2554,
1993
44. Holmsen H, Weiss HJ: Further evidence for a deficient storage pool of adenine nucleotides in platelets from some patients with thrombocytopathia
45.
Weiss HJ,
Witte LD,
Kaplan KL,
Lages BA,
Chernoff A,
Nossel HL,
Goodman De WS Baumgartner HR:
Heterogeneity in storage pool deficiency: Studies on granule-bound substances in 18 patients including variants deficient in
46. Weiss HJ: Inherited abnormalities of platelet granules and signal transduction, in Colman RW, Hirsh J, Marder VJ, Salzman EW (eds): Hemostasis and Thrombosis: Basic Principles and Clinical Practice (ed 3). Philadelphia, PA, Lippincott, 1993, p 673
47.
Monkovic DD,
Tracy PB:
Functional characterization of human platelet-released factor V and its activation by factor Xa and thrombin.
J Biol Chem
265:17732,
1990
48.
Weiss HJ,
Pietu G,
Meyer D,
Rabinowitz R,
Girma JP,
Rogers J:
Heterogeneous abnormalities in the multimeric structure, antigenic properties, and plasma/platelet content of FVIII/vWf in classical (Type I) and three sub-types of variant (Type II) von Willebrand's disease.
J Lab Clin Med
101:411,
1983[Medline]
[Order article via Infotrieve]
49.
Lages B,
Scrutton MC,
Holmsen H:
Studies on gel-filtered human platelets: Isolation and characterization in a medium containing no added Ca2+, Mg2+, or K+.
J Lab Clin Med
85:811,
1975[Medline]
[Order article via Infotrieve]
50.
Wiedmer T,
Esmon CT,
Sims PJ:
Complement proteins C5b-9 stimulate procoagulant activity through platelet prothrombinase.
Blood
68:875,
1986
51.
Lages B,
Weiss HJ:
Evidence for a role of glycoprotein IIb-IIIa, distinct from its ability to support aggregation, in platelet activation by ionophores in the presence of extracellular divalent cations.
Blood
83:2549,
1994
52.
Rink TJ,
Pozzan T:
Using quin2 in cell suspensions.
Cell Calcium
6:133,
1985[Medline]
[Order article via Infotrieve]
53. Salvadori MG, Baron ML: Numerical methods in engineering. Englewood Cliffs, NJ, Prentice-Hall, 1964
54.
Weiss HJ,
Lages B,
Vicic W,
Tsung LY,
White JG:
Heterogeneous abnormalities of platelet dense granule ultrastructure in 20 patients with congenital storage pool deficiency.
Br J Haematol
83:282,
1993[Medline]
[Order article via Infotrieve]
55.
Lages BA,
Holmsen H,
Weiss HJ,
Dangelmaier C:
Thrombin and ionophore A23187-induced dense granule secretion in storage pool deficient platelets: Evidence for impaired nucleotide storage as the primary dense granule defect.
Blood
61:154,
1983
56.
Lages B,
Shattil SJ,
Bainton DF,
Weiss HJ:
Decreased content and surface expression of alpha-granule membrane protein GMP-140 in one of two types of platelet alpha-delta storage pool deficiency.
J Clin Invest
87:919,
1991
57.
Lages B,
Sussman II,
Levine SP,
Coletti D,
Weiss HJ:
Platelet alpha granule deficiency associated with decreased P-selectin and selective impairment of thrombin-induced activation in a new patient with gray platelet syndrome (
58.
Weiss HJ,
Turitto VT,
Baumgartner HR:
Platelet adhesion and thrombus formation of subendothelium in platelets deficient in glycoprotein IIb-IIIa, Ib, and storage granules.
Blood
67:322,
1986
59.
Coller BS:
A new murine monoclonal antibody reports an activation-dependent change in the conformation and/or microenvironment of the platelet GPII/IIIa complex.
J Clin Invest
76:101,
1985
60.
Coller BS,
Peerschke EI,
Scudder LE,
Sullivan CA:
A murine monoclonal antibody that completely blocks the binding of fibrinogen to platelets produces a thrombasthenic-like state in normal platelets and binds to glycoproteins IIb and/or IIIa.
J Clin Invest
72:325,
1983
61. Chen F, Coller BS, Weiss HJ, Xu LZ, French DL: Glanzmann thrombasthenia due to a glycoprotein IIb missense mutation. Leu214 Pro. Thromb Haemost 73:1191, 1995 (abstr)
62.
Ahmad SS,
Rawala-Sheikh R,
Ashby B,
Walsh PN:
Platelet receptor-mediated factor X activation by factor IXa: High-affinity factor IXa receptors induced by factor VIII are deficient on platelets in Scott syndrome.
J Clin Invest
84:824,
1989
63.
Bevers EM,
Wiedmer T,
Comfurius P,
Shattil SJ,
Weiss HJ,
Zwaal RFA,
Sims PJ:
Defective Ca2+ induced microvesiculation and deficient expression of procoagulant activity in erythrocytes from a patient with a bleeding disorder: A study of the red blood cells of Scott syndrome.
Blood
79:380,
1992
64.
Kohima H,
Newton-Nash D,
Weiss HJ,
Sims PJ,
Zhao J,
Wiedmer T:
Production and characterization of transformed B-lymphocytes expressing the membrane defect of Scott syndrome.
J Clin Invest
94:2237,
1994
65.
Miletich JP,
Majerus DW,
Majerus PW:
Patients with congenital factor V deficiency have decreased factor Xa binding sites on their platelets.
J Clin Invest
62:824,
1978
66.
Lages B,
Dangelmaier CA,
Holmsen H,
Weiss HJ:
Specific correction of impaired acid hydrolase secretion in storage pool deficient platelets by adenosine diphosphate.
J Clin Invest
81:1865,
1988
67.
Bevers EM,
Wiedmer T,
Comfurius P,
Zhao J,
Smeets EF,
Schlegel RA,
Shroit AJ,
Weiss HJ,
Williamson P,
Zwaal RFA,
Sims PJ:
The complex of phosphatidylinositol 4,5-biphosphate and calcium ions is not responsible for Ca2+-induced loss of phospholipid asymmetry in the human erythrocyte. A study in Scott syndrome, a disorder of calcium-induced phospholipid scrambling.
Blood
86:1983,
1995
68.
Srivastava PC,
Powling MJ,
Nokes TJC,
Patrick AD,
Dawes J,
Hardisty RM:
Grey platelet syndrome: Studies on platelet alpha-granules, lysosomes and defective response to thrombin.
Br J Haematol
65:441,
1987[Medline]
[Order article via Infotrieve]
69.
Tracy PB,
Giles AR,
Mann KG:
Factor V (Quebec): A bleeding diathesis associated with a qualitative platelet factor V deficiency.
J Clin Invest
74:1221,
1984
70.
Hayward CPM,
Rivard GE,
Kane WH,
Drouin J,
Zheng S,
Moore JC,
Kelton JG:
An autosomal dominant, qualitative platelet disorder associated with multimerin deficiency, abnormalities in platelet factor V, thrombospondin, von Willebrand factor, and fibrinogen and an epinephrine aggregation defect.
Blood
87:4967,
1996
71.
Hayward CPM,
Furmaniak-Kazmierczak E,
Cieutat A-M,
Moore JC,
Bainton DF,
Nesheim ME,
Kelton JG,
Cote G:
Factor V is complexed with multimerin in resting platelet lysates and colocalizes with multimerin in platelet
72.
Janeway CM,
Rivard GE,
Tracy PB,
Mann KG:
Factor V Quebec revisited.
Blood
87:3571,
1996
73.
Reverter JC,
Kessels H,
Beguin S,
Kumar R,
Hemker HC,
Coller BS:
Inhibition of platelet-mediated, tissue factor-induced thrombin generation by the mouse/human chimeric 7E3 antibody.
J Clin Invest
98:863,
1996[Medline]
[Order article via Infotrieve]
74.
Sage SO,
Reast R,
Rink TJ:
ADP evokes biphasic Ca2+ influx in fura-2-loaded human platelets: Evidence for Ca2+ entry regulated by the intracellular Ca2+ store.
Biochem J
265:675,
1990[Medline]
[Order article via Infotrieve]
75.
Brass LF,
Shattil SJ:
Identification and function of the high affinity binding sites for Ca2+ on the surface of platelets.
J Clin Invest
73:626,
1984
76.
Brass LF:
Ca2+ transport across the platelet plasma membrane. A role for membrane glycoproteins IIB and IIIA.
J Biol Chem
260:2231,
1985
77.
Rybak MEM,
Renzulli LA:
Effect of calcium channel blockers on platelet GPIIb-IIIa as a calcium channel in liposomes: Comparison with effects on the intact platelet.
Thromb Haemost
67:131,
1992[Medline]
[Order article via Infotrieve]
78.
Yamaguchi A,
Tanour K,
Yamazaki H:
Secondary signals mediated by GPIIb/IIIa in thrombin-activated platelets.
Biochim Biophys Acta
1054:8,
1990[Medline]
[Order article via Infotrieve]
79.
Williams JA,
Ashby B,
Daniel JL:
Ligands to the platelet fibrinogen receptor glycoprotein GPIIb/IIIa do not affect agonist-induced second messengers Ca2+ or cyclic AMP.
Biochem J
270:149,
1990[Medline]
[Order article via Infotrieve]
80.
Powling MJ,
Hardisty RM:
Glycoprotein GPIIb/IIIa complex and Ca2+ influx into stimulated platelets.
Blood
66:731,
1985
81.
Sinigaglia F,
Bisio A,
Torti M,
Balduini CL,
Bertolino G,
Balduini C:
Effect of GPIIb/IIIa complex ligands on calcium ion movement and cytoskeleton organization in activated platelets.
Biochem Biophys Res Commun
154:258,
1988[Medline]
[Order article via Infotrieve]
82.
Cadroy Y,
Hanson SR,
Andrew BK,
Marzec UM,
Evatt BL,
Kunicki TJ,
Montgomery RR,
Harker LA:
Relative antithrombotic effects of monoclonal antibodies targeting different platelet glycoprotein-adhesive molecule interactions in nonhuman primates.
Blood
83:3218,
1994
83.
Coller BS,
Anderson K,
Weisman HF:
New antiplatelet agents: Platelet GPIIb/IIIa antagonists.
Thromb Haemost
74:302,
1995[Medline]
[Order article via Infotrieve]
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
 |
 |
|||||||
 |
 |
 |
 |
 |
 |
 |
 |
||
| Copyright © 1997 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||
A Comparison With Scott Syndrome
Abstract
Introduction
Abstract
A comparison with Glanzmann's thrombasthenia and von Willebrand's disease.
Am J Med
43:570,
1967
