[Management of a high risk of thrombosis patient with drug-eluting stents undergoing a complete gastrectomy]. / Stratégie de prise en charge d'un patient porteur d'endoprothèses coronaires pharmacoactives à haut risque thrombotique pour une gastrectomie totale.

We report the case of a 70-year-old patient, with two drug-eluting stents (DES), scheduled for a complete gastrectomy for a gastric cancer. This case underlines management problems regarding a patient with a high risk of DES thrombosis in case of AAP withdrawal and a high risk of bleeding in case of AAP maintenance. At this time, no evidence-based recommendation is available for clinicians to manage these patients. Our strategy was therefore based on platelet function monitoring test, which is however neither available in clinical practice nor validated to predict haemorrhagic risk. Several biologic tests are under study; they could be useful to guide perioperative management of antiplatelet therapy in the clinical setting of surgical patients with DES.

Fibrinogen angers with a new deletion (gamma GVYYQ 346-350) causes hypofibrinogenemia with hepatic storage.

INTRODUCTION: This study reports a family with chronically abnormal blood liver function tests (LFT) and congenital hypofibrinogenemia. The proposita had cirrhosis initially related to alcohol abuse and chronic viral hepatitis C (HCV), but abnormal LFT persisted even when alcohol intake was stopped and despite HCV treatment was efficient based on serum RNA negative testing. RESULTS: Needle biopsy specimens of the proposita and her brother showed eosinophilic intra-cytoplasmic inclusions that reacted strongly with fibrinogen antisera on direct immunofluorescence. Electron microscopic examination showed that the rough endoplasmic reticulum was filled with inclusions that consisted of densely packed, curved tubular structures arranged in a fingerprint-like pattern. Coagulation studies revealed low functional and antigenic fibrinogen concentrations suggestive of hypofibrinogenemia. Amplification and DNA sequencing showed a heterozygous deletion of the a7690 to g7704 nucleotides of the gamma chain gene in the 3'end of exon 8 (g 7690_7704del14; Genbank access M10014); this deletion encompassed the splicing site at position 7703 and predicts in a new putative consensus splicing sequence (AATGgtatgtt). RNA was extracted from a liver specimen from the proposita's brother. The cDNA obtained by reverse transcription polymerase chain reaction confirmed the usage of a newly generated donor site at position 7688 of the genomic sequence resulting in an in-frame heterozygous 5 amino acid deletion (GVYYQ 346-350; p.G372_Q376del) and that this mutation is responsible for a new splicing site at position 7688 of the genomic sequence. CONCLUSION: we suggest that the molecular defect in fibrinogen Angers results in an impaired assembly and causes defective secretion and hepatic storage of fibrinogen.

[Predictive value of D-dimer assay in superficial thrombophlebitis of the lower limbs]. / Valeur des D-dimères lors des thromboses veineuses superficielles des membres inférieurs.

OBJECTIVE: The negative predictive value of D-dimer (DD) assay in patients with venous thromboembolic disease is well established for deep vein thrombosis and pulmonary embolism. Little is known about the value of DD assay in patients with superficial thrombophlebitis (ST). The purpose of this study was to assess the value of DD assay in patients with ST of the lower limb. METHOD: The study group was composed of 100 consecutive patients, irrespective of age. Patients with clinical manifestations suggestive of ST of the lower limbs with positive duplex color Doppler evidence confirming the diagnosis and DD assay results (Vidas D-Dimer Exclusion) within 24 hours were included in the study. Patients with thrombosis in another site in addition to the superficial vein of the lower limb, those taking anticoagulants for more than 48 hours, and those with a condition known to potentially elevate DD levels were excluded. The volume of the thrombus was determined echographically and reported as mean diameter and length. RESULTS: Sixty-two women and 38 men were included. Mean age (+/- 5) was 58 years +/- 13.48 (range 18-90; median: 57). The ST involved the Great saphenous (n=74), the small saphenous (n=11) or another vein (n=15). Mean thrombus volume was 4453 mm(3) +/- 7101 (range 94-38484; median: 1751). Mean DD level was 829 ng/ml +/- 516.72 (range 100-2567; median: 715.5). DD assay was negative (<500 ng/ml) in 32 patients (32%) and positive in 68 (68%). For these three items, there was no significant difference between ST with and without varicose veins. DD assay was always positive (>or=500 ng/ml) in all patients aged over 70 years (n=22). In patients aged less than 70 years (n=78), DD assay was positive in 46 (59%) and negative in 32 (41%). DD level was positively correlated with thrombus volume in patients aged less than 70 years (P<0.0001). ROC analysis, sensitivity as a function of specificity by thrombus volume for the entire population, determined the usefulness of a negative DD assay. Considering the critical threshold at 5914 mm(3), sensitivity was 1.0 (95CI 0.89-1.0), with 0.29 specificity (95CI 0.19-0.42), 1.00 negative predictive value and 0.75 positive predictive value. However, the thrombus volume was less than this threshold value in three of the nine cases of ST with extension to the terminal portion of the saphenous. CONCLUSION: A positive DD assay was observed in 68% of patients with ST, with no significant difference with or without varicose veins. The test was positive in all patients aged over 70 years and in 59% of those aged under 70 years. There was a correlation between DD level and thrombus volume, yielding a threshold volume (5914 m(3)) above which all DD tests were positive. Nevertheless, this threshold volume was too great to include all ST extending to the terminal portion of the saphenous. Measurement of DD level is thus not contributive to the diagnosis of ST.

[Treatment by lepirudin and acenocoumarol of heparin induced thrombocytopenia after valvular surgery: a word of caution]. / Traitement par lépirudine et acénocoumarol d'une thrombopénie induite par l'héparine après chirurgie valvulaire: conseils de prudence.

The diagnosis and treatment of type II heparin-induced thrombocytopenia (HIT) after valvular surgery raise difficult issues due to the substitution of heparin by other anticoagulants. A 50-year-old man with hepatic cirrhosis and acute infective endocarditis underwent aortic valve replacement. On the 4th postoperative day platelet count decreased to 50 g/l. Platelet aggregation was demonstrated in vitro with unfractioned and low molecular weigh heparins and danaparoid sodium. As serum creatinine was 94 micromol/l, lepirudine (r-hirudin) was administered at recommended doses. However, six hours later hirudinaemia estimated by ecarin-clotting time was 3 mg/l and lepirudine dose had to be divided by 15 in order to reach therapeutic levels. Similarly, INR increased up to 6,7 on the 11th postoperative day after acenocoumarol 1 mg daily was administered. Despite the presence of oesophageal, gastric and duodenal lesions at risk of haemorrhage no bleeding was detected. The reasons for overdosage are discussed. The necessity of measurement or calculation of creatinine clearance before lepirudine prescription and frequent hirudinaemia during treatment is emphasized.

Two novel fibrinogen variants found in patients with pulmonary embolism and their families.

BACKGROUND: The occurrence of dysfibrinogen is quite rare in comparison with other hemostatic defects, specially in cases of venous thrombosis. OBJECTIVES: Fibrinogen is known to have multiple functions, which are not evaluated by simple coagulation testing. We have used gel electrophoresis to search for new mutations. PATIENTS AND METHODS: Specimens of purified fibrinogen from 217 consecutive patients with familial or recurrent or early thrombosis and from 490 control subjects were evaluated by electrophoresis. Plasma fibrinogen levels and coagulation-dependent tests (electromechanical and optical coagulometric determinations, immunological measurement, thrombin and Reptilase(R) times) were normal. RESULTS: Two novel familial variants were detected. For a 42-year-old patient, an in-frame 117 base pair insertion in the Aalpha-chain gene caused a 5-kDa mobility shift of the Aalpha chain. This corresponds to a 39 amino acid duplication in the connector domain (fibrinogen Champagne au Mont d'Or). This pattern was also found in the patient's mother and child. A second 31-year-old patient presented an extra band under non-reducing conditions, 30 kDa larger than HMW fibrinogen and reacting with antifibrinogen antibodies (fibrinogen Lozanne). A heterozygous 5909A-->G mutation was found on the Bbeta-chain gene leading to heterozygous Bbeta Tyr236--> stop codon. The predicted truncated Bbeta chain could participate in chain assembly. Two family members were also affected, one of whom had suffered early venous thrombosis. CONCLUSIONS: Electrophoretic testing of apparently normal fibrinogens can reveal new variants which may be clinically relevant.

Human plasma fibrinogen measurement derived from activated partial thromboplastin time clot formation.

Prothrombin time-derived measurement of fibrinogen (PTd) has already been described. Activated partial thromboplastin time-derived measurement of fibrinogen (aPTTd) has not yet been clearly defined. Using an MDA II coagulometer (Organon Teknika, Durham, North Carolina, USA), we have therefore compared fibrinogen levels determined with Clauss, PTd, and aPTTd assays and an enzyme immunoassay (EIA) in 172 samples. Of these, 47 were from pre-operative controls, 18 from patients with liver disease, 28 from patients with hyperfibrinogenaemia, 33 from patients treated with vitamin K antagonists, 22 from patients treated with unfractionated heparin and 24 from haemophilic patients. Within the normal range, interassay and intra-assay variations were comparable. For control samples, PTd, aPTTd and Clauss assays were well correlated, without any systematic error. EIA was also correlated but values were slightly higher (mean of difference = 0.24). Pathological samples showed an overestimation of fibrinogen when using PTd measurements in patients treated with vitamin K antagonists, as well as when using aPTTd measurements in patients presenting with factor VIII and factor IX deficiencies. These results indicate that, despite expected financial savings, aPTTd fibrinogen measurements should not be used without restriction. PTd and aPTTd fibrinogen determinations are provided without any additional cost. Their comparison with Clauss fibrinogen results may constitute a validation tool or have additional diagnostic utility (e.g. identifying polymerization abnormalities in case of dissimilar results).

A database for human fibrinogen variants.

Identifying and studying abnormal human fibrinogens is a source of much information, and helps in taking care of the affected patients. To permit exhaustive numbering and easy updates, an extensive register has been compiled and made available on the internet. Known molecular abnormalities are mentioned with the essential clinical features.

Cardiac surgery with cardiopulmonary bypass in patients with type II heparin-induced thrombocytopenia.

BACKGROUND: The use of cardiopulmonary bypass (CPB) in patients with a history of type II heparin-induced thrombocytopenia (HIT) may be associated with complications related to their anticoagulation management. METHODS: Between January 1997 and December 1999, among 4,850 adults patients who underwent cardiac surgery in our institution, 10 patients presented with preoperative type II HIT. In 4 patients, anticoagulation during CPB was achieved with danaparoid sodium. In 6 other patients, heparin sodium was used after pretreatment with epoprostenol sodium. RESULTS: No significant change in platelet count occurred in any patient. No intraoperative thrombotic complication was encountered. Total postoperative chest drainage ranged from 250 to 1,100 ml in patients pretreated with epoprostenol and 1,700 to 2,470 ml in patients who received danaparoid sodium during CPB (p < 0.05, Mann-Whitney U test). CONCLUSIONS: During CPB, inhibition of platelet aggregation by prostacyclin may be a safe anticoagulation approach in patients with type II HIT.

Spontaneous intracerebral hemorrhage revealing Addison's disease.

We report a case of spontaneous intracerebral hemorrhage occurring in a young woman and revealing Addison's disease. This autoimmune primary adrenocortical insufficiency was associated with premature ovarian failure. Exhaustive research for nonhypertensive causes of intracerebral hemorrhage was negative. Initial coagulation studies disclosed severe hypofibrinogenemia and prolonged prothrombin time related to vitamin K-dependent coagulation factor deficit. Clotting abnormalities cleared at 4 months under treatment with hydrocortisone. Glucocorticoids are potent regulators of fibrinogen biosynthesis, increasing fibrinogen secretion. We conclude that primary adrenocortical insufficiency induced this hemorrhagic diathesis leading to spontaneous intracerebral hemorrhage. This latter has never been reported in Addison's disease. Primary adrenocortical insufficiency should be considered as a rare potential cause of nonhypertensive intracerebral hemorrhage.

[Diagnosis of venous thrombosis and/or pulmonary embolism by determination of d-dimers using ELISA. Review based on a study of 80 consecutive patients hospitalized in an emergency unit]. / Le diagnostic de la thrombose veineuse et/ou de l'embolie pulmonaire par le dosage des D-Dimères ELISA. Mise au point à partir d'une étude portant sur 80 patients consécutifs hospitalisés dans un service d'urgence médicale.

The sensitivity and specificity of an ELISA method (Fibrinostika Fbdp Organon Teknika) for assay of D-dimers in the diagnosis of deep vein thrombosis and/or pulmonary embolism was studied in 80 consecutive patients seen at an emergency unit. Fifty-six of the patients presented clinical signs of deep vein thrombosis. Diagnosis was confirmed in 26 of the 56 patients with a D-dimer level above 370 ng/ml (sensitivity 92.3%) and 370 ng/ml for 13 of 30 patients with a negative venous ultrasound Doppler examination (specificity 43.3%). The positive predictive value was 58.5% and the negative predictive value was 87%. There was a significant difference in the level of D-dimers between distal and proximal deep vein thrombosis. In 40 cases with suspected pulmonary embolis, either alone or with suspected deep vein thrombosis, diagnosis was made in only 4 of 9 with a highly or intermediately probable ventilation/perfusion scan. D-dimer level was always above 3,000 ng/ml. Coupling the ELISA dimer test with noninvasive explorations improves negative predictive value but can also avoid invasive explorations (venography, pulmonary angiography) in certain patients. A D-dimer test as sensitive as the ELISA test and as rapid as the latex test remains to be described.

Increased plasma free gamma carboxyglutamic acid levels during deep vein thrombosis and intravascular disseminated coagulation.

Gammacarboxyglutamic acid (gla) is a non essential amino acid synthesized in presence of vitamin K, predominantly found in coagulation and bone proteins. In 14 cases of deep vein thrombosis and in 11 cases of disseminated intravascular coagulation, compared to 19 normal subjects and 9 patients hospitalized for leg pain, free plasma gla levels were found significantly elevated (respectively 372 +/- 244 and 559 +/- 361 versus 146 +/- 34 and 120 +/- 40 pmol/mL). In six paired plasma and serum, gla levels were similar. These results suggest an involvement of blood coagulation in gla generation with need of a catabolism of the activated factors. A significant decrease was noticed during vitamin K antagonist therapy and liver disease, both instances in which the synthesis of gla containing coagulation factors is affected. During hepatocellular carcinoma with elevated desgamma carboxyprothrombin, gla was found normal, denying an global impairement of the vitamin K metabolism.

Role of platelet membrane glycoproteins Ib/IX and IIb/IIIa, and of platelet alpha-granule proteins in platelet aggregation induced by human osteosarcoma cells.

We have previously shown that the platelet-aggregating activity of human MG-63 and HOS osteosarcoma cells depends at least in part upon tumor cell surface-associated thrombospondin, and suggested that platelet-osteosarcoma cell interactions could occur through interactions with specific platelet membrane receptors. In this study, the platelet-aggregating activity of MG-63 and HOS cells was studied by using a variety of platelet disorders. Both osteosarcoma cell lines induced a biphasic platelet aggregation response when added to normal platelet-rich plasma, while the second phase of aggregation was absent when added to gray platelets (deficiency in alpha-granule proteins) and to aspirin-treated platelets. Platelets from two unrelated patients with type I Glanzmann's thrombasthenia (deficiency in glycoprotein (GP) GPIIb/IIIa) did not aggregate at all with osteosarcoma cells. Using giant platelets from three patients with Bernard-Soulier syndrome (deficiency in GPIb/IX), the aggregation response induced by MG-63 and HOS cells was monophasic and reversible when compared to normal-sized platelets and to giant platelets from a patient with May-Hegglin anomaly (no membrane GP defect). Because GPIb serves as a receptor for von Willebrand factor during hemostasis, aggregation experiments were also conducted with the platelet-rich plasma of two patients with a low plasma von Willebrand factor concentration (type I von Willebrand's disease) before and after the infusion of deamino-D-arginine vasopressin. MG-63 and HOS cells induced biphasic platelet aggregation both before and after deamino-D-arginine vasopressin treatment, while the ristocetin-dependent binding of von Willebrand factor to platelets only occurred after deamino-D-arginine vasopressin treatment. Preincubation of normal platelet-rich plasma with monoclonal antibody SZ-2 directed against the von Willebrand binding domain of GPIb did not inhibit the platelet-aggregation activity of osteosarcoma cells, whereas anti-GPIb antibody SZ-2 did inhibit ristocetin-induced platelet agglutination. In addition, anti-GPIX antibodies did not affect platelet-osteosarcoma cell interactions. In conclusion, our data demonstrate that the first phase of the platelet-aggregating activity of human osteosarcoma cells is initiated by the interaction of these tumor cells with platelet membrane GPIIb/IIIa, whereas the second phase, even if plasma von Willebrand factor is deficient, involves platelet membrane GPIb and the participation of platelet alpha-granule proteins in membrane-mediated events, making aggregation irreversible.

Plasma erythropoietin in essential thrombocythaemia.

Plasma erythropoietin levels were frequently decreased in patients with essential thrombocythaemia (14/31 cases), as in polycythaemia vera. These two diseases or some forms of them might be two facets of a single disease process.

Substitution of cysteine for phenylalanine 751 in mature von Willebrand factor is a novel candidate mutation in a family with type IIA von Willebrand disease.

Type IIA is a variant form of von Willebrand disease (vWD) characterized by the absence of von Willebrand factor (vWF) high molecular weight multimers in plasma. Most of the candidate missense mutations potentially responsible for type IIA vWD have been found clustered within a short segment of vWF, lying between Gly742 and Glu875 of the mature subunit. The present work reports a single heterozygous T-->G transversion in eight patients from a large type IIA vWD family, resulting in the substitution Phe751-->Cys. The absence of this mutation in 100 normal vWF genes as well as the lack, in these patients, of any other abnormality within the whole exon 28 encoding amino acids 463-921 of mature vWF, provide a strong support that this non-conservative mutation may be at the origin of the disease in this family. The presence of an additional cysteine at position 751 may induce a conformational change of the vWF subunit affecting either its 'in vivo' sensitivity to proteolytic cleavage or, more likely, its intracellular transport as suggested by the abnormal multimeric pattern of platelet vWF observed in these patients.

Des-gamma-carboxyprothrombin detection by immunoblotting after polyacrylamide gel affinoelectrophoresis in human plasmas.

In the absence of vitamin K or in the presence of the vitamin K antagonists, abnormal nonfunctional forms of prothrombin circulate in the blood. A reliable and reproducible technique, derived from traditional crossed affinoimmunoelectrophoresis in presence of calcium lactate, was developed and optimized. The technique is based on nondenaturing polyacrylamide gel affinoelectrophoresis, with calcium lactate, of plasma samples, followed by immunoblotting with rabbit anti-human prothrombin serum and detection with an anti-rabbit immunoglobulin peroxidase conjugate. Depending on the plasmas, one or two bands were visualized and quantified by densitometry of the immunoblots. The technique was able to detect abnormal des-gamma-carboxylated prothrombins at concentration of 0.1 microgram/mL.