A New Dysfibrinogenemia: Fibrinogen Oslo IV

1983 ◽  
Vol 49 (02) ◽  
pp. 120-122 ◽  
Author(s):  
H Stormorken ◽  
F Brosstad ◽  
H Seim

SummaryA family with dysfibrinogenemia is described. The abnormal fibrinogen occurred in three successive generations indicating a dominant hereditary pattern. Thrombin and reptilase times were about twice the normal value. This was shown to be caused by a polymerization defect, fibrinopeptide release being normal. Platelet aggregation was undisturbed, indicating normal platelet-fibrinogen binding. The bleeding time was normal and there was no bleeding tendency. However, an obscure recurrent pulmonary ailment may, or may not, be related to the dysfibrinogenemia. The abnormal fibrinogen was tentatively termed Oslo IV.

1975 ◽  
Vol 33 (02) ◽  
pp. 278-285 ◽  
Author(s):  
Şeref Inceman ◽  
Yücel Tangün

SummaryA constitutional platelet function disorder in a twelve-year-old girl characterized by a lifelong bleeding tendency, prolonged bleeding time, normal platelet count, normal clot retraction, normal platelet factor 3 activity and impaired platelet aggregation was reported.Platelet aggregation, studied turbidimetrically, was absent in the presence of usual doses of ADP (1–4 μM), although a small wave of primary aggregation was obtained by very large ADP concentrations (25–50 μM). The platelets were also unresponsive to epinephrine, thrombin and diluted collagen suspensions. But an almost normal aggregation response occurred with strong collagen suspensions. The platelets responded to Ristocetin. Pelease of platelet ADP was found to be normal by collagen and thrombin, but impaired by kaolin. Platelet fibrinogen content was normal.The present case, investigated with recent methods, confirms the existence of a type of primary functional platelet disorder characterized solely by an aggregation defect, described in 1955 and 1962 under the name of “essential athrombia.”


1987 ◽  
Author(s):  
M P Gordge ◽  
R W Faint ◽  
P B Rylance ◽  
G H Neild

The bleeding tendency of uraemia may be related to reduction by anaemia of erythrocyte/platelet interaction, toxic inhibition of platelet aggregation and abnormal von Willebrand Factor (vWF) mediated platelet adhesion. Our aim in this study was to determine at what stage of renal failure bleeding time becomes prolonged and to investigate the mechanisms involved.We have measured bleeding time (Simplate II), plasma levels of fibrinogen and vWF, and ex-vivo platelet responsiveness in 31 patients with chronic renal failure (CRF) of various degrees of severity and compared them with values obtained in 22 healthy controls. No patient was dialysed, nephrotic or suffering from immunological renal disease. Patients were divided into mild (plasma creatinine <300 umol/1), n=10, moderate (300-600 umol/1), n=14, or severe (>600 umol/1), n=7, CRF.Bleeding time became significantly prolonged only in severe CRF (p<0.005). Haematocrit fell as renal failure advanced, and correlated with bleeding time (r=0.40, p<0.05). Platelet counts were normal. Platelet aggregation in response to ristocetin (mediated by vWF) and ADP increased progressively (p<0.005 in severe CRF), as did spontaneous aggregation (p<0.005 in severe CRF). This was associated with an increase in plasma vWF and fibrinogen (p<0.005 in severe CRF). Collagen induced aggregation was slightly, but not significantly increased. Thromboxane (TxB2) generation in clotting blood was the only measurement that showed a reduced platelet response (p<0.025 in severe CRF).In summary, a bleeding tendency develops late in the course of progressive CRF when plasma creatinine has risen to at least 600 umol/1. Platelet aggregation is enhanced rather than reduced and platelet interaction with vWF is not defective. Anaemia appears more important than abnormal platelet aggregation in mediating uraemic bleeding, although reduced serum TxB2 generation suggests a defect in platelet response to endogenous thrombin which may also contribute. Increased platelet aggregation and fibrinogen concentrations might promote glomerular thrombosis and contribute to the progression of CRF.


1979 ◽  
Author(s):  
Z.M. Ruggeri ◽  
F.I. Pareti ◽  
P.M. Mannucci ◽  
T.S. Zimmerman

Initial reports of ristocetin-induced platelet aggregation (RIPA) demonstrated it to be decreased in some patients with vWd. We now report 20 patients (from five unrelated families) in whom RIP A was increased, apparently as the result of an increased ristocetin-induced binding of Factor VIIIrelated antigen (VIIIR:Ag) to platelets. All the patients had a life-long bleeding tendency, with prolonged bleeding time, and an abnormal two-dimensional crossed immunoelectrophoresis (2DCIE). Increased RIPA was demonstrated by measuring the minimum ristocetin concentration necessary to induce platelet aggregation. This was 0.42 mg/ml á 0.11 SD in the patients, and 0.91 á 0.097 SD in 17 normals (t = 13.83; P < 0.001). VIIIR:Ag binding to platelets occurred at ristocetin concentrations (0.4 mg/mI) which were ineffective in normals (who required >0.6 mg/mI). In contrast, the VIIIR:Ag of other patients with abnormal 2DCIE and markedly decreased RIP A did not bind to platelets at ristocetin concentrations as high as I mg/ml. It has been previously demonstrated that 30% to 60% of normal VIIIR:Ag binds to isolated human platelet membranes in the absence of ristocetin or any other agent, and that binding is restricted to the larger forms of VIIIR:Ag. However, VIIIR:Ag from the patients with increased RIPA, including two with normal ristocetin cofactor activity, showed decreased or undetectable binding as did all other patients with abnormal 2DCIE. This study suggests that ristocetin induced platelet Factor VIII interaction does not accurately reflect the “bleeding time factor” defect in vWd.


1994 ◽  
Vol 5 (1) ◽  
pp. 36-46
Author(s):  
M P Gawaz ◽  
G Dobos ◽  
M Späth ◽  
P Schollmeyer ◽  
H J Gurland ◽  
...  

Impaired platelet function and a bleeding tendency are well-recognized complications of chronic renal failure. Because the fibrinogen receptor GPIIb-IIIa plays a central role in platelet aggregation and adhesion to the subendothelium, it was reasoned that a defect in this receptor may underlie the impaired platelet function in uremia. To test this hypothesis, the function of this receptor in the platelets of 11 uremic patients was studied. Aggregation studies were performed with flow cytometric techniques with anti-GPIIb-IIIa conformation-specific monoclonal antibodies (mAb) (anti-LIBS1 and anti-PMI-1). Antifibrinogen and antithrombospondin mAb were used to characterize fibrinogen binding to GPIIb-IIIa and the release of alpha-granules, respectively. Platelets from patients with chronic renal failure showed significantly decreased binding of conformation-dependent anti-LIBS1 mAb after ADP, phorbol myristate acetate, or RGD-peptide stimulation compared with normal controls, suggesting a defect related to the ability of the fibrinogen receptor to undergo a conformational change. Moreover, antifibrinogen and antithrombospondin binding to activated platelets were reduced in uremic patients, implying impairment of both ligand-binding and alpha-granule release. Hemodialysis partially restored GPIIb-IIIa function, which may account for the observed effects of this therapy in restoring platelet aggregation. These findings indicate that platelets of patients with chronic renal failure reveal an aggregation defect at least partially due to an intrinsic GPIIb-IIIa dysfunction and the presence of a putative uremic toxin that inhibits fibrinogen binding to GPIIb-IIIa.


2006 ◽  
Vol 96 (08) ◽  
pp. 167-175 ◽  
Author(s):  
Yutaka Matsumoto ◽  
Hisao Takizawa ◽  
Kazuhiro Nakama ◽  
Xiaoqi Gong ◽  
Yoshihisa Yamada ◽  
...  

SummaryRecent progress in the understanding of thrombus formation has suggested an important role of glycoprotein (GP)VI. In contrast to its pivotal role in collagen-induced platelet activation, it has been suggested that its blockade does not induce massive bleeding tendency. To demonstrate the dissociation between inhibitory effect on platelet aggregation and bleeding by GPVI blockade, we examined the effects of Fab fragment of OM2, an anti-human GPVI monoclonal antibody on ex vivo collagen-induced platelet aggregation and skin bleeding time after intravenous injection in cynomolgus monkeys. In a dose-escalation study, OM2 potently (>80%) inhibited collagen-induced platelet aggregation at the cumulative dose of 0. 2 mg/kg with a slight prolongation of bleeding time (1. 3 times baseline value). Furthermore, at 18. 8 mg/kg, the highest dose tested, prolongation of bleeding time was still mild (1. 9 times). In contrast, abciximab, Fab fragment of anti-GPIIb/IIIa antibody prolonged bleeding time by 5. 0 times at 0. 35 mg/kg, the lowest effective dose on platelet aggregation. Ina pharmacodynamic study,a bolus injection of OM2 at 0. 4 mg/kg produced potent inhibition of collagen-induced aggregation up to six hours after injection, showing longer half-life than that of abciximab. The injection of OM2 Fab did not induce thrombocytopenia and GPVI depletion in monkeys. These results suggest that blockade of GPVI by antibody can exerta potent inhibitory effect on collagen-induced platelet aggregation with a milder prolongation of bleeding time than blockade of GPIIb/IIIa. This study indicates that OM2 has the potential to be developed as a new class of therapeutic tool.


Blood ◽  
1972 ◽  
Vol 39 (4) ◽  
pp. 490-499 ◽  
Author(s):  
Harold M. Maurer ◽  
James A. Wolff ◽  
Sue Buckingham ◽  
Arthur R. Spielvogel

Abstract Functional, biochemical, and morphologic platelet abnormalities are reported in four children with the syndrome of albinism, mild bleeding tendency, prolonged bleeding time, and normal platelet count. In these children, primary platelet aggregation with adenosine diphosphate occurred normally, but secondary aggregation was impaired. Collagen and norepinephrine produced almost no platelet aggregation. Platelet content of serotonin (5-HT) was markedly reduced, and uptake and retention of 5-HT by the platelets in vivo and in vitro was poor. In one child who was given a tryptophan load, urinary tryptophan metabolites were normal, suggesting that there was no evidence of a block in the 5-HT synthetic pathway in the gastrointestinal tract. Electron microscopy revealed an absence of densely osmophilic granules in 5-HT poor platelets. Platelets from other albinos with no history of bleeding contained normal amounts of 5-HT and densely osmophilic granules.


2000 ◽  
Vol 83 (02) ◽  
pp. 309-315 ◽  
Author(s):  
Axel Herr ◽  
Johann Motsch ◽  
Alexandra Holzmann ◽  
Jörg Weimann ◽  
Friedemann Taut ◽  
...  

SummaryThe platelet inhibitory effect of 0-40 ppm inhaled nitric oxide (NO) was investigated in healthy men and women. In both groups, ADPand collagen-induced platelet aggregation was significantly inhibited 20 (T20) and 40 min (T40) after the beginning of inhalation of 5, 10, and 40 ppm. Moreover, in both men and women, the in vitro bleeding time was significantly prolonged at T20 and T40 during inhalation of 40 ppm. Inhalation of NO also inhibited P-selectin expression at 5, 10, and 40 ppm and fibrinogen binding to the GPIIb/IIIa-receptor at 40 ppm. In conclusion, in healthy volunteers, the platelet inhibitory effect of inhaled NO was not dose-related, since it was significant at 5 and 10 ppm but did not increase during the administration of higher NO concentrations. In addition, gender-related differences were only observed in ADP-induced platelet aggregation at 10 ppm and in bleeding time prolongation at 40 ppm.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3894-3894
Author(s):  
Rabih C. Fahed ◽  
Thomas K. Schulz2

Abstract Propofol is one of the most commonly used anesthetic drugs, with rapid induction, maintenance and recovery times. Its relative safety has resulted in it becoming a popular choice for general anesthesia. A 56 y o woman with no prior history of bleeding underwent laparoscopic cholecystectomy. Postoperatively she experienced bleeding to the degree that open laparotomy was required to achieve hemostasis.Two years later, she underwent open sigmoid resection under propofol anesthesia for refractory diverticulitis. Severe postoperative bleeding ensued, necessitating IV fluid resuscitation and transfusion of packed red blood cells.Template bleeding time was repeatedly greater than 20 minutes on the first postoperative day. Platelet count, coagulation studies, von Willebrand disease assays, fibrinogen level and fibrinolytic system assays were found to be normal. Platelet aggregation in response to arachidonic acid was decreased at 9% (reference 60 - 120 %). The patient received platelet transfusions; hemostasis was achieved and the template bleeding time returned to normal on the second postoperative day and remained normal on repeat testing several weeks later. A few reports have shown an increased bleeding with propofol, which is thought to be related to inhibition of thromboxane A2 synthesis and increased synthesis of leucocyte nitric oxide. Some studies show increased bleeding even without any change in the template bleeding time. In summary, we report a case of a propofol-induced life threatening bleeding dyscrasia associated with a prolonged template bleeding time and platelet aggregation studies consistent with decreased response to arachidonic acid. This rarely reported complication should always be in the differential diagnosis of postoperative bleeding given the widespread usage of propofol anesthesia in major surgeries.


Blood ◽  
2007 ◽  
Vol 110 (9) ◽  
pp. 3183-3191 ◽  
Author(s):  
Catherine Léon ◽  
Anita Eckly ◽  
Béatrice Hechler ◽  
Boris Aleil ◽  
Monique Freund ◽  
...  

Abstract Mutations in the MYH9 gene encoding the nonmuscle myosin heavy chain IIA result in bleeding disorders characterized by a macrothrombocytopenia. To understand the role of myosin in normal platelet functions and in pathology, we generated mice with disruption of MYH9 in megakaryocytes. MYH9Δ mice displayed macrothrombocytopenia with a strong increase in bleeding time and absence of clot retraction. However, platelet aggregation and secretion in response to any agonist were near normal despite absence of initial platelet contraction. By contrast, integrin outside-in signaling was impaired, as observed by a decrease in integrin β3 phosphorylation and PtdIns(3,4)P2 accumulation following stimulation. Upon adhesion on a fibrinogen-coated surface, MYH9Δ platelets were still able to extend lamellipodia but without stress fiber–like formation. As a consequence, thrombus growth and organization, investigated under flow by perfusing whole blood over collagen, were strongly impaired. Thrombus stability was also decreased in vivo in a model of FeCl3-induced injury of carotid arteries. Overall, these results demonstrate that while myosin seems dispensable for aggregation and secretion in suspension, it plays a key role in platelet contractile phenomena and outside-in signaling. These roles of myosin in platelet functions, in addition to thrombocytopenia, account for the strong hemostatic defects observed in MYH9Δ mice.


1979 ◽  
Author(s):  
H. F. Woods ◽  
J. Turney ◽  
M. J. Weston

Impaired platelet aggregation to ADP and collagen is recognised in uraemia and the loss of normal platelet function contributes to the prolonged capillary bleeding time observed in uraemia. in von Willebrand’s disease prolongation of capillary bleeding time is associated with impaired platelet aggregation to ristocetin because of a relative or absolute deficiency of the Factor VIII-Ristocetin Cofactor. We have studied platelet aggregation to ristocetin and Factor VIII coagulant activity (CA) and related antigen (RA) in 14 uraemic and 28 dialysed patients. Ristocetin aggregation (delta-0.D/min) was significantly less in uraemia (50 ± 21: m ± S.D) and in dialysis patients (38 ± 18) than in controls (78 ± 20). Factor VIII CA and RA were significantly higher in uraemic and dialysed patients than in controls.In crossover studies plasma from uraemic patients either enhanced or did not change ristocetin aggregation of normal platelets but plasma from dialysed patients impaired ristocetin aggregation of normal platelets. Plasma from dialysed patients was not contaminated by heparin. Thus in uraemia impaired platelet aggregation to ristocetin is unlikely to be due to a Factor VIII deficiency and may be due to a membrane defect as in Bernard-Soulier disease. in dialysed patients’ plasma there appears to be an additional circulating inhibitor of platelet-ristocetin interaction.


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