RESUMO
OBJECTIVE: Activation of platelets by subendothelial collagen results in an increase of cytosolic Ca(2+) concentration ([Ca(2+)]i) and is followed by platelet activation and thrombus formation that may lead to vascular occlusion. The present study determined the role of phosphoinositide-dependent protein kinase 1 (PDK1) in collagen-dependent platelet Ca(2+) signaling and ischemic stroke in vivo. APPROACH AND RESULTS: Platelet activation with collagen receptor glycoprotein VI agonists collagen-related peptide or convulxin resulted in a significant increase in PDK1 activity independent of second-wave signaling. PDK1 deficiency was associated with reduced platelet phospholipase Cγ2-dependent inositol-1,4,5-trisphosphate production and intracellular [Ca(2+)]i in response to stimulation with collagen-related peptide or convulxin. The defective increase of [Ca(2+)]i resulted in a substantial defect in activation-dependent platelet secretion and aggregation on collagen-related peptide stimulation. Furthermore, Rac1 activation and spreading, adhesion to collagen, and thrombus formation under high arterial shear rates were significantly diminished in PDK1-deficient platelets. Mice with PDK1-deficient platelets were protected against arterial thrombotic occlusion after FeCl3-induced mesenteric arterioles injury and ischemic stroke in vivo. These mice had significantly reduced brain infarct volumes, with a significantly increased survival of 7 days after transient middle cerebral artery occlusion without increase of intracerebral hemorrhage. Tail bleeding time was prolonged in pdk1(-/-) mice, reflecting an important role of PDK1 in primary hemostasis. CONCLUSIONS: PDK1 is required for Ca(2+)-dependent platelet activation on stimulation of collagen receptor glycoprotein VI, arterial thrombotic occlusion, and ischemic stroke in vivo.
Assuntos
Proteínas Quinases Dependentes de 3-Fosfoinositídeo/metabolismo , Plaquetas/enzimologia , Sinalização do Cálcio , Colágeno/metabolismo , Infarto da Artéria Cerebral Média/enzimologia , Ativação Plaquetária , Trombose/enzimologia , Proteínas Quinases Dependentes de 3-Fosfoinositídeo/deficiência , Proteínas Quinases Dependentes de 3-Fosfoinositídeo/genética , Animais , Modelos Animais de Doenças , Predisposição Genética para Doença , Infarto da Artéria Cerebral Média/sangue , Infarto da Artéria Cerebral Média/patologia , Inositol 1,4,5-Trifosfato/sangue , Camundongos Knockout , Neuropeptídeos/sangue , Fenótipo , Fosfolipase C gama/sangue , Adesividade Plaquetária , Agregação Plaquetária , Glicoproteínas da Membrana de Plaquetas/deficiência , Glicoproteínas da Membrana de Plaquetas/genética , Trombose/sangue , Trombose/patologia , Fatores de Tempo , Proteínas rac1 de Ligação ao GTP/sangueRESUMO
BACKGROUND: Methylene blue pathogen inactivation and storage of thawed plasma both lead to changes in the activity of several clotting factors. We investigated how this translates into a global loss of thrombin generation potential and alterations in the protein C pathway. MATERIALS AND METHODS: Fifty apheresis plasma samples were thawed and each divided into three subunits. One subunit was stored for 7 days at 4 °C, one was stored for 7 days at 22 °C and one was stored at 4 °C after methylene blue/light treatment. Thrombin generation parameters, ProC(®)Global-NR, prothrombin time and activated partial thromboplastin time were assessed on days 0 and 7. RESULTS: The velocity of thrombin generation increased significantly after methylene blue treatment (increased thrombin generation rate; time to peak decreased) and decreased after storage (decreased thrombin generation rate and peak thrombin; increased lag time and time to peak). The endogenous thrombin generation potential remained stable after methylene blue treatment and storage at 4 °C. Methylene blue treatment and 7 days of storage at 4 °C activated the protein C pathway, whereas storage at room temperature and storage after methylene blue treatment decreased the functional capacity of the protein C pathway. Prothrombin time and activated partial thromboplastin time showed only modest alterations. DISCUSSION: The global clotting capacity of thawed plasma is maintained at 4 °C for 7 days and directly after methylene blue treatment of thawed plasma. Thrombin generation and ProC(®)Global are useful tools for investigating the impact of pathogen inactivation and storage on the clotting capacity of therapeutic plasma preparations.
Assuntos
Preservação de Sangue/métodos , Azul de Metileno/farmacologia , Tempo de Tromboplastina Parcial , Plasma/metabolismo , Tempo de Protrombina , Esterilização/métodos , Trombina/metabolismo , Testes de Coagulação Sanguínea , Criopreservação/métodos , Humanos , Luz , Plasma/efeitos dos fármacos , Plasma/efeitos da radiação , Proteína C/metabolismoRESUMO
BACKGROUND: Hemoglobin (Hb) is screened before whole blood donation to protect donors from anemia. Recently, noninvasive methods have become available for Hb screening in blood donors. We compared a noninvasive, a capillary, and a venous method for Hb screening of blood donors. STUDY DESIGN AND METHODS: Consecutive donors were prospectively screened using a noninvasive (Masimo Pronto-7), a capillary (HemoCue Hb 301), and a venipuncture-based method as gold standard (Siemens Advia 2120i) for Hb determination. All measurements were performed in parallel and in duplicate. A cutoff Hb value of 125 g/L (females) and 135 g/L (males) was used for donor acceptance. RESULTS: A total of 553 donors were analyzed; in 38 donors (7%) the noninvasive Hb method was not applicable due to technical reasons. The noninvasive test underestimated (mean bias, -5.9 g/L; 95% limits of agreement, -25.74, 13.88) and the capillary test overestimated Hb values (mean bias, 4.3 g/L; 95% limits of agreement, -8.13, 16.71). Coefficients of variation of duplicate measurements were 1.05 (venous), 2.73 (noninvasive), and 3.23 (capillary). The noninvasive test revealed false low Hb values in 21.2% and the capillary test revealed false high Hb values in 9% of donors compared to the venous method. The negative predictive value of the noninvasive test was 94.3%. CONCLUSION: The noninvasive Hb measurement is a reasonable first-line approach for predonation Hb screening of blood donors but a second method should be available to retest those not testable with the noninvasive device or with Hb values below the cutoffs.
Assuntos
Doadores de Sangue , Eritrócitos/química , Hemoglobinas/análise , Adulto , Capilares , Feminino , Humanos , Masculino , Estudos ProspectivosRESUMO
Data on the frequency of anti-platelet factor 4/heparin (PF4/H) antibodies and their association with outcomes in intensive care unit (ICU) patients are sparse. In this prospective, observational study we screened 320 consecutive surgical/medical ICU patients for anti-PF4/H antibodies by enzyme-immunoassay (EIA) for immunoglobulin (Ig)G/A/M separately and heparin-induced platelet activation assay (HIPA) at ICU admission (=baseline), day 6, and day 10. HIPA-positive patients were additionally tested by serotonin-release assay (SRA). Patients tested positive by day 10: for anti-PF4/H-IgG = 17.2 % and for anti-PF4/H-IgM = 42.1 %. Within the first 10 ICU days, platelet counts decreased to <100 Gpt/L in 27.8 % patients. However, only seven patients (2.2 %) experienced a drop in the platelet count ≥50 % beginning after the fourth ICU day. These included the only two patients (0.6 %; 95 % confidence interval 0.08-2.2 %) with heparin-induced thrombocytopenia (HIT). Only strong reactions in the HIPA were reproducible by SRA. This study confirms that testing for anti-PF4/H IgG antibodies should be restricted to ICU-patients who develop a platelet count decrease of >50 % that begins after day four of heparin treatment (which may have started before ICU admission). Among patients testing positive by IgG-specific EIA a functional platelet activation assay should be performed (regarding only strong reactions as positive).
Assuntos
Anticoagulantes , Autoanticorpos , Heparina , Ativação Plaquetária , Fator Plaquetário 4 , Trombocitopenia , Idoso , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Anticoagulantes/imunologia , Autoanticorpos/sangue , Autoanticorpos/imunologia , Feminino , Heparina/administração & dosagem , Heparina/efeitos adversos , Heparina/imunologia , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Ativação Plaquetária/efeitos dos fármacos , Ativação Plaquetária/imunologia , Contagem de Plaquetas , Fator Plaquetário 4/sangue , Fator Plaquetário 4/imunologia , Estudos Prospectivos , Trombocitopenia/sangue , Trombocitopenia/induzido quimicamente , Trombocitopenia/epidemiologia , Trombocitopenia/imunologia , Trombocitopenia/patologiaRESUMO
Thrombocytopenia can cause diagnostic challenges in patients who have received heparin. Heparin-induced thrombocytopenia (HIT) is often considered in the differential diagnosis, and a positive screening can be mistaken as confirmation of the disorder. We present two patients who both received low-molecular-weight heparin for several days. In the first patient, clinical judgment rejected the suspicion of HIT despite a positive screening assay, and treatment for the alternative diagnosis of post-transfusion purpura was correctly initiated. In the second patient, the inaccurate diagnosis HIT was pursued due to a positive screening assay, while the alternative diagnosis of drug-dependent thrombocytopenia caused by piperacillin/tazobactam was rejected. This resulted in re-exposure to piperacillin/tazobactam which caused a second episode of severe thrombocytopenia. A positive screening assay for platelet factor 4/heparin-antibody should be verified by a functional assay, especially in patients with low pretest probability for HIT.
Assuntos
Heparina/efeitos adversos , Fator Plaquetário 4/sangue , Púrpura Trombocitopênica/induzido quimicamente , Púrpura Trombocitopênica/diagnóstico , Trombocitopenia/induzido quimicamente , Trombocitopenia/diagnóstico , Idoso , Estado Terminal , Diagnóstico Diferencial , Ensaio de Imunoadsorção Enzimática , Fraturas do Colo Femoral/complicações , Humanos , Metotrexato/efeitos adversos , Pancitopenia/induzido quimicamente , Ácido Penicilânico/efeitos adversos , Ácido Penicilânico/análogos & derivados , Piperacilina/efeitos adversos , Contagem de Plaquetas , Fator Plaquetário 4/imunologia , Tazobactam , Reação TransfusionalRESUMO
BACKGROUND: Heparin-induced thrombocytopenia (HIT) is caused by platelet-activating antibodies that recognize platelet factor 4/heparin (PF4/hep) complexes. The in vitro demonstration of PF4/hep antibodies using functional and immunological methods is essential for optimal management of patients suspected to have HIT. Since functional assays are technically challenging and limited to specialized laboratories, antigen-binding assays are commonly used in routine laboratories. STUDY DESIGN: Blood samples from 448 consecutive patients in whom HIT was suspected were investigated using a latex agglutination test HemosIL® HIT-Ab(PF4-H) (HemosIL-Ab), two chemiluminescence tests HemosIL AcuStar HIT-Ab(PF4-H) (HemosIL AcuStar-Ab) and AcuStar HIT-IgG(PF4-H) (HemosIL AcuStar-IgG), an in-house PF4/hep IgG enzyme immunoassay (EIA) and the heparin induced platelet aggregation (HIPA) test. RESULTS: Antibodies against PF4/hep were detectable in 44 out of 119 samples using HemosIL-Ab among which 20 samples were also reactive in the HIPA; and in 122, 64 and 108 out of 448 sera using HemosIL AcuStar-Ab, HemosIL AcuStar-IgG and in-house PF4/hep IgG-EIA, respectively, among which 52 sera were also reactive in the HIPA. All assays had high sensitivities of >95% for platelet activating antibodies; however, they differed in their specificities. The highest specificity and positive predictive value was observed by HemosIL AcuStar-IgG (96% and 78%, respectively). CONCLUSION: Automated immunoassays are useful in the laboratory investigations of HIT and present a potential improvement toward standardization of laboratory investigations of HIT. The high positive predictive capability may justify treating the patient with alternative anticoagulants without waiting for the results of a functional assay.
Assuntos
Heparina/efeitos adversos , Imunoensaio/métodos , Trombocitopenia/diagnóstico , Trombocitopenia/imunologia , Aglutinação , Automação , Heparina/química , Humanos , Técnicas Imunoenzimáticas , Imunoglobulina G/química , Látex/química , Luminescência , Agregação Plaquetária , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Trombocitopenia/induzido quimicamenteRESUMO
BACKGROUND: Circulating procoagulant microparticles (MPs) are thought to be involved in the pathogenesis of venous thromboembolism in patients with inflammatory bowel disease (IBD). However, the exposure of tissue factor, the primary initiator of coagulation activation, on microparticles (TF(+)MPs) and its association with hemostasis activation has not yet been studied in IBD patients. METHODS: In this case-control study 49 IBD patients (28 Crohn's disease, 21 ulcerative colitis) and 49 sex- and age-matched, healthy controls were included. Clinical disease activity (Crohn's Disease Activity Index and Clinical Activity Index, respectively) was assessed and IBD-related data were determined by chart review. Numbers, cellular origin and procoagulant activity of TF(+)MPs in plasma were determined using flow cytometry and a chromogenic activity assay. D-dimer and high-sensitive C-reactive protein (CRP) served as markers for coagulation activation and inflammation, respectively. The primary endpoint was the number of TF(+)MPs in IBD patients compared to controls. RESULTS: Median number (interquartile range) of TF(+)MPs was higher in IBD patients than in controls (14.0 (11.9-22.8)×10(3)/mL vs. 11.9 (11.9-19.1)×10(3)/mL plasma, P=0.029). This finding was due to generally higher plasma levels of MPs from platelets and leukocytes in IBD patients. However, the number of TF(+)MPs was neither correlated with their procoagulant activity and D-dimer nor with disease activity and CRP. CONCLUSIONS: Increased numbers of circulating TF(+)MPs represent a new facet of hemostatic abnormalities in IBD. However, the lack of association with activation of the coagulation system and disease activity questions their pathogenetic role for venous thromboembolism in this patient group.
Assuntos
Coagulação Sanguínea , Micropartículas Derivadas de Células/metabolismo , Doenças Inflamatórias Intestinais/sangue , Tromboplastina/metabolismo , Adulto , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
BACKGROUND: Rapid transfusion of fresh-frozen plasma (FFP) is desired for treating coagulopathies, but thawing and issuing of FFP takes more than 40 minutes. Liquid storage of plasma is a potential solution but uncertainties exist regarding clotting factor stability. We assessed different storage conditions of thawed FFP and plasma treated by methylene blue plus light (MB/light) for pathogen inactivation. STUDY DESIGN AND METHODS: Fifty thawed apheresis plasma samples (approx. 750 mL) were divided into three subunits and either stored for 7 days at 4°C, at room temperature (RT), and at 4°C after MB/light treatment. Clotting factor activities (Factor [F] II, FV, FVII through FXIII, fibrinogen, antithrombin, von Willebrand factor antigen, Protein C and S) were assessed after thawing and on Days 3, 5, and 7. Changes were classified as "minor" (activities within the reference range) and "major" (activities outside the reference range). RESULTS: FFP storage at 4°C revealed major changes for FVIII (median [range], 56% [33%-114%]) and Protein S (51% [20%-88%]). Changes were more pronounced when plasma was stored at RT (FVIII, 59% [37%-123%]; FVII, 69% [42%-125%]; Protein S, 20% [10%-35%]). MB/light treatment of thawed FFP resulted in minor changes. However, further storage for 7 days at 4°C revealed major decreases for FVIII (47% [12%-91%]) and Protein S (49% [18%-95%]) and increases for FVII (150% [48%-285%]) and FX (126% [62%-206%]). CONCLUSION: Storage of liquid plasma at 4°C for 7 days is feasible for FFP as is MB/light treatment of thawed plasma. In contrast, storage of thawed plasma for 7 days at RT or after MB/light treatment at 4°C affects clotting factor stability substantially and is not recommended.
Assuntos
Armazenamento de Sangue/métodos , Preservação de Sangue/métodos , Patógenos Transmitidos pelo Sangue/efeitos dos fármacos , Azul de Metileno/farmacologia , Plasma/efeitos dos fármacos , Coagulação Sanguínea/efeitos dos fármacos , Coagulação Sanguínea/efeitos da radiação , Remoção de Componentes Sanguíneos/métodos , Patógenos Transmitidos pelo Sangue/efeitos da radiação , Temperatura Baixa , Criopreservação/métodos , Inibidores Enzimáticos/farmacologia , Humanos , Luz , Plasma/efeitos da radiaçãoRESUMO
OBJECTIVE: Pregnancy is a hypercoagulable state. We evaluated global markers of coagulation activation, ProCGlobal (Siemens Healthcare Diagnostics, Eschborn, Germany) and endogenous thrombin potential (ETP), in pregnant women with and without low-molecular-weight (LMW) heparin prophylaxis. STUDY DESIGN: We prospectively followed 113 healthy women and 61 women receiving LMW heparin prophylaxis throughout pregnancy. ProCGlobal and ETP were measured in venous blood during the first, second, and third trimester. RESULTS: ProCGlobal decreased significantly throughout pregnancy in all women and was lower in anticoagulated women (P < .001 for all comparisons). ETP levels remained unchanged until the third trimester and then significantly decreased in all women. ETP was higher in anticoagulated women than in healthy women at all time points. CONCLUSION: ProCGlobal levels decrease throughout pregnancy. In pregnant women at high thrombotic risk, coagulation activation reflected by low ProCGlobal and high ETP levels is substantial despite LMW heparin prophylaxis.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Complicações Hematológicas na Gravidez/sangue , Proteína C/metabolismo , Trombina/metabolismo , Trombofilia/sangue , Adulto , Análise de Variância , Anticoagulantes/uso terapêutico , Feminino , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Gravidez , Complicações Hematológicas na Gravidez/tratamento farmacológico , Estudos Prospectivos , Proteína C/análise , Trombina/análise , Trombofilia/tratamento farmacológicoRESUMO
BACKGROUND: Microparticles (MPs) have procoagulant properties as shown in vitro and in animal models. Their role in haemostatic system activation at the site of a vascular injury in vivo in humans has not been studied. MATERIAL AND METHODS: In a prospective randomized crossover study, 13 healthy volunteers were given 100 mg acetylsalicylic acid or placebo daily for 7 days. Number and cellular origin, expression of tissue factor (TF) and phosphatidylserine on MPs, and platelet and coagulation activation markers [beta-thromboglobulin (beta-TG), prothrombin fragment f1.2 (f1.2)] were measured in venous blood and in blood from a vascular injury (shed blood) by flow cytometry and immunoassays, respectively. RESULTS: The number of MPs was significantly higher in shed blood than in venous blood. The majority of MPs were platelet derived. The expression of TF on MPs was low, but higher in shed blood than in venous blood. TF positive MPs were significantly higher in shed blood, which was due to an increase of MPs from platelets (PMPs). In shed blood, the number of TF expressing platelet-derived MPs correlated with beta-TG, but not with f1.2. Low dose acetylsalicylic acid did not affect shedding of PMPs, neither in venous blood nor in shed blood. CONCLUSIONS: The release of PMPs locally at the site of platelet plug formation in humans indicates a possible role of MPs for haemostatic system activation in vivo. Low dose acetylsalicylic acid might not be strong enough to suppress shedding of PMPs in the microcirculation.
Assuntos
Aspirina/farmacologia , Micropartículas Derivadas de Células/efeitos dos fármacos , Micropartículas Derivadas de Células/metabolismo , Fosfatidilserinas/metabolismo , Ativação Plaquetária/efeitos dos fármacos , Tromboplastina/metabolismo , Adulto , Biomarcadores/metabolismo , Coagulação Sanguínea/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Citometria de Fluxo , Humanos , Imunoensaio , Masculino , Fragmentos de Peptídeos/sangue , Ativação Plaquetária/fisiologia , Estudos Prospectivos , Protrombina , beta-Tromboglobulina/análiseRESUMO
BACKGROUND: Increased thrombin generation is associated with an increased risk of recurrent venous thromboembolism. We investigated the relation between endogenous thrombin potential (ETP) and risk of recurrent venous thromboembolism and evaluated whether prediction of recurrence can be improved by a combined analysis of ETP and D-dimer. METHODS: We followed 861 patients with first spontaneous venous thromboembolism and determined ETP and D-dimer after discontinuation of anticoagulation. Patients with natural inhibitor deficiency, lupus anticoagulant, or cancer were excluded. The study endpoint was symptomatic recurrent venous thromboembolism. RESULTS: One hundred thirty patients (15.1%) had recurrence. High ETP (> or = 100%) conferred a 1.6-fold increased risk of recurrence (95% CI 1.1-2.3) after adjustment for age, sex, factor V Leiden, factor II G20210A, and duration of anticoagulation. After adjustment for D-dimer, risk of recurrence remained significantly higher among patients with high ETP [hazard ratio 1.6 (95% CI 1.01-2.4)]. After adjustment for ETP, high D-dimer (> or = 0.5 mg/L) conferred a 1.8-fold (95% CI 1.1-2.8) increased risk of recurrence. Compared with patients with low ETP and low D-dimer, risk of recurrence was 2.8-fold (95% CI 1.5-5.3) higher among patients with both high ETP and high D-dimer after adjustment for potential confounders. CONCLUSIONS: ETP and D-dimer are independent predictors of recurrent venous thromboembolism. Assessing risk of recurrence can be optimized by combining these indicators of thrombin generation.
Assuntos
Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Trombina/análise , Tromboembolia Venosa/diagnóstico , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Probabilidade , Estudos Prospectivos , Recidiva , Medição de RiscoRESUMO
BACKGROUND: Excess body weight is a risk factor for a first venous thromboembolism. The impact of excess body weight on risk of recurrent venous thrombosis is uncertain. METHODS: We studied 1107 patients for an average of 46 months after a first unprovoked venous thromboembolism and withdrawal of anticoagulant therapy. Excluded were pregnant patients, those requiring long-term antithrombotic treatment, and those who had a previous or secondary thrombosis, natural coagulation inhibitor deficiency, lupus anticoagulant, or cancer. Our study end point was symptomatic recurrent venous thromboembolism. RESULTS: A total of 168 patients had recurrent venous thromboembolism. Mean (SD) body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) was significantly higher among patients with recurrence than among those without recurrence: 28.5 (6.0) vs 26.9 (5.0) (P = .01). The relationship between excess body weight and recurrence was linear; the adjusted hazard ratio for each 1-point increase in BMI was 1.044 (95% confidence interval [CI], 1.013-1.076) (P < .001). Four years after discontinuation of anticoagulant therapy, the probability of recurrence was 9.3% (95% CI, 6.0%-12.7%) among patients of normal weight and 16.7% (95% CI, 11.0%-22.3%) and 17.5% (95% CI, 13.0%-22.0%) among overweight and obese patients, respectively. Compared with patients of normal weight, the hazard ratio of recurrence adjusted for age, sex, factor V Leiden, prothrombin G20210A mutation, high factor VIII levels, and type of initial venous thromboembolic event was 1.3 (95% CI, 0.9-1.9) (P = .20) among overweight patients and 1.6 (95% CI, 1.1-2.4) (P = .02) among obese individuals. The population attributable risk corresponding to excess body weight was 26.8% (95% CI, 5.3%-48.2%). CONCLUSION: Excess body weight is a risk factor of recurrent venous thromboembolism.
Assuntos
Obesidade/epidemiologia , Sobrepeso/epidemiologia , Tromboembolia Venosa/epidemiologia , Distribuição por Idade , Anticoagulantes/uso terapêutico , Áustria/epidemiologia , Fatores de Coagulação Sanguínea/análise , Índice de Massa Corporal , Proteína C-Reativa/análise , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Fatores de Risco , Distribuição por Sexo , Tromboembolia Venosa/tratamento farmacológicoRESUMO
Peripheral T-cell lymphomas (PTCL) have a variable outcome. We have investigated the prognostic value of molecular staging in non-anaplastic PTCL. T-cell receptor gamma rearrangements were routinely determined in peripheral blood (n = 40) and bone marrow (n = 38) of patients with PTCL (75% unspecified) by conventional PCR at diagnosis. Tissue controls for PCR included 24 tumour biopsies. Twenty-four patients (60%) had a PCR-detectable clonal TCR gamma rearrangement in PB or BM. These TCR gamma PCR positive patients had significantly more stage IV disease (14 patients of 15 patients; P = 0.001), elevated LDH (14 of 18 patients; P = 0.04), higher IPI (16 of 21 patients; P = 0.03), more anemia (15 of 19 patients; P = 0.02) and lower platelet counts (seven of seven patients; P = 0.02). Clinical outcome of this clonal group was characterised by lower complete remission rates (37.5% vs. 62.5%), and overall response rates (58.3% vs. 87.5%; P < 0.05) as well as a significantly shorter median overall survival (12.8 vs. 30.0 months; P = 0.006). Patients with clinical stages I - III but molecular stage IV had an equally poor overall survival when compared with patients with clinical stage IV (15.8 vs. 13.9 months). In contrast, patients with CS I - III in the absence of a TCR gamma rearrangement in PB or BM had a favourable outcome with an estimated overall survival of 70% at 3 and 5 years. Molecular staging in PB and BM by TCR gamma PCR at diagnosis may serve as a useful prognostic tool in PTCL.
Assuntos
Rearranjo Gênico , Linfoma de Células T Periférico/diagnóstico , Receptores de Antígenos de Linfócitos T gama-delta/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Sanguíneas , Medula Óssea , Feminino , Humanos , Linfoma de Células T Periférico/mortalidade , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prognóstico , Indução de Remissão , Taxa de Sobrevida , Resultado do TratamentoRESUMO
In patients with venous thromboembolism (VTE) a laboratory assay that globally measures the overall thrombophilic tendency is not available. We hypothesized that determination of ProC((R)) Global, a plasma assay which tests the global function of the protein C pathway, could be used to stratify patients according to their risk of recurrent VTE. We prospectively followed 774 patients with first spontaneousVTE for a mean time of 52 months. ProC Global normalized ratio (NR) was measured in plasma by use of a commercially available assay based on activated partial thromboplastin time. Ninety-eight of the 774 patients had recurrentVTE. Patients with ProC Global NR > or = 0.75 had a relative risk of recurrence of 0.59 (95% CI 0.40-0.87) as compared with those with lower ratio. After four years, cumulative probability of recurrence was 8.6% in patients with ProC Global NR > or = 0.75 and 17.4% in patients with a lower ratio (p = 0.006). Patients with a high ProC Global NR have a low risk of recurrent VTE. ProC Global NR can be used to stratify patients with a first unprovoked VTE according to their risk of recurrence.
Assuntos
Tempo de Tromboplastina Parcial , Proteína C/metabolismo , Kit de Reagentes para Diagnóstico , Tromboembolia Venosa/diagnóstico , Adulto , Anticoagulantes/uso terapêutico , Áustria , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Estudos Prospectivos , Recidiva , Medição de Risco , Sensibilidade e Especificidade , Fatores de Tempo , Tromboembolia Venosa/sangue , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/prevenção & controleRESUMO
Low plasma vitamin B6, measured as pyridoxal-5'-phosphate (PLP), is associated with an increased risk of first venous thromboembolism (VTE). In a prospective cohort of 757 patients with first VTE we investigated the association of PLP levels with risk of recurrent VTE. After 4 years, the likelihood of VTE recurrence among patients with PLP < or =23.3 nmol/L and 14.4% (11.5%-17.4%) among those with PLP >23.3 nmol/L was 22.5% (95% CI 13.6%-31.5%) (p=0.01). Patients with PLP ''23.3 nmol/L had 1.8-fold higher recurrence risk (1.01-3.14) than patients with PLP >23.3 nmol/L (adjusted for confounders including homocysteine). Therefore, low vitamin B6 is a risk factor of recurrent VTE.
Assuntos
Tromboembolia/epidemiologia , Trombose Venosa/epidemiologia , Deficiência de Vitamina B 6/epidemiologia , Adolescente , Estudos de Coortes , Feminino , Humanos , Masculino , Estudos Prospectivos , Recidiva , Fatores de Risco , Tromboembolia/sangue , Trombose Venosa/sangue , Deficiência de Vitamina B 6/sangueRESUMO
The clinical relevance of high P-selectin levels in venous thrombosis is unknown. We prospectively followed 544 patients with first unprovoked venous thromboembolism (VTE) after cessation of anticoagulation and evaluated P-selectin as a risk factor of recurrent VTE. VTE recurred in 63 (12%) patients. Patients with recurrence had significantly higher P-selectin levels than those without (45.8 mg/dl +/- 16.4 vs. 40.1 mg/dl +/- 13.3; p = 0.006). After four years, the probability of recurrence was 20.6% (95% confidence interval [CI] 12.6-28.5) among patients with P-selectin values above the 75(th) percentile of the patient population and was 10.8% (95% CI 7.2-14.3) among patients with lower values (p = 0.046). Compared to patients with low P-selectin, adjusted risk of recurrence was 1.7-fold (95% CI 1.0-2.9, p = 0.045) increased among patients with P-selectin levels exceeding the 75(th) percentile. We conclude that high circulating P-selectin is a risk factor of recurrent VTE.
Assuntos
Selectina-P/sangue , Tromboembolia/sangue , Trombose Venosa/sangue , Adulto , Áustria/epidemiologia , Biomarcadores/sangue , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Recidiva , Medição de Risco , Fatores de Risco , Tromboembolia/epidemiologia , Tromboembolia/etiologia , Fatores de Tempo , Regulação para Cima , Trombose Venosa/epidemiologia , Trombose Venosa/etiologiaRESUMO
BACKGROUND: High-density lipoprotein (HDL) protects against arterial atherothrombosis, but it is unknown whether it protects against recurrent venous thromboembolism. METHODS AND RESULTS: We studied 772 patients after a first spontaneous venous thromboembolism (average follow-up 48 months) and recorded the end point of symptomatic recurrent venous thromboembolism, which developed in 100 of the 772 patients. The relationship between plasma lipoprotein parameters and recurrence was evaluated. Plasma apolipoproteins AI and B were measured by immunoassays for all subjects. Compared with those without recurrence, patients with recurrence had lower mean (+/-SD) levels of apolipoprotein AI (1.12+/-0.22 versus 1.23+/-0.27 mg/mL, P<0.001) but similar apolipoprotein B levels. The relative risk of recurrence was 0.87 (95% CI, 0.80 to 0.94) for each increase of 0.1 mg/mL in plasma apolipoprotein AI. Compared with patients with apolipoprotein AI levels in the lowest tertile (<1.07 mg/mL), the relative risk of recurrence was 0.46 (95% CI, 0.27 to 0.77) for the highest-tertile patients (apolipoprotein AI >1.30 mg/mL) and 0.78 (95% CI, 0.50 to 1.22) for midtertile patients (apolipoprotein AI of 1.07 to 1.30 mg/mL). Using nuclear magnetic resonance, we determined the levels of 10 major lipoprotein subclasses and HDL cholesterol for 71 patients with recurrence and 142 matched patients without recurrence. We found a strong trend for association between recurrence and low levels of HDL particles and HDL cholesterol. CONCLUSIONS: Patients with high levels of apolipoprotein AI and HDL have a decreased risk of recurrent venous thromboembolism.
Assuntos
Lipoproteínas HDL/fisiologia , Embolia Pulmonar/epidemiologia , Trombofilia/sangue , Trombose Venosa/epidemiologia , Adulto , Idoso , Anticorpos Antifosfolipídeos/sangue , Apolipoproteína A-I/sangue , Apolipoproteínas B/sangue , Áustria/epidemiologia , HDL-Colesterol/sangue , Estudos de Coortes , Suscetibilidade a Doenças , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Lipoproteínas HDL/sangue , Masculino , Pessoa de Meia-Idade , Ressonância Magnética Nuclear Biomolecular , Estudos Prospectivos , Embolia Pulmonar/sangue , Recidiva , Risco , Fatores de Risco , Fatores Sexuais , Trombose Venosa/sangueRESUMO
The pathogenesis of hypercoagulability in cancer is not entirely understood. We hypothesized that in cancer patients circulating tissue factor-positive microparticles (TF (+) MPs) are increased and associated with hemostatic system activation. In 20 patients with advanced colorectal cancer and in 20 age- and sex-matched controls, number and cellular origin of TF (+) MPs were determined in plasma by flow cytometry. D-dimer was determined as an indicator of hemostatic system activation. Compared to controls, the median (interquartile range) number of TF (+) MPs was two-fold higher in cancer patients: 25.9 (15.4 - 42.0) x 10 (3) /ml plasma versus 13.1 (11.9 - 19.7) x 10 (3) /ml plasma, p = 0.007. This was mainly due to a higher amount of TF (+) MPs from platelets (13.4 [5.0 - 17.4] x 10 (3) /ml plasma vs. 5.8 [4.5 - 7.5] x 10 (3) /ml plasma, p = 0.017). TF (+) MPs correlated with D-dimer ( ? = 0.48, p = 0.002). High levels of TF (+) MPs in cancer patients and their correlation with D-dimer suggest that TF (+) MPs might be involved in hemostasis activation in cancer patients.
Assuntos
Membrana Celular/química , Neoplasias Colorretais/sangue , Trombofilia/etiologia , Tromboplastina/análise , Coagulação Sanguínea , Neoplasias Colorretais/complicações , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Citometria de Fluxo , Hemostasia , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho da PartículaRESUMO
BACKGROUND: The single nucleotide polymorphism (SNP) Ser128Arg in the E-selectin gene is overrepresented in certain patient populations with atherosclerosis or restenosis. As this SNP enhances tissue factor-triggered coagulation in humans during systemic inflammation, we hypothesized that it may also predispose for the development of recurrent venous thromboembolism (VTE). METHODS: A total of 585 patients were prospectively observed after first VTE for recurrent, objectively documented, symptomatic VTE. Patients with secondary VTE, homozygous factor V Leiden, natural inhibitor deficiencies, lupus anticoagulant, or long-term anticoagulation therapy were excluded. The S128R SNP was genotyped by mutagenically separated polymerase chain reaction. RESULTS: A total of 102 patients (17%) were heterozygous, and 11 were homozygous (2%) for the Ser128Arg mutation. Ninety patients (15%) had recurrent VTE during follow-up. Homozygosity for the Ser128Arg SNP increased the cumulative likelihood, particularly for early recurrent VTE (log rank test, P<.05) and was an independent predictor of recurrent VTE (hazard ratio [HR], 4.1; 95% confidence interval [CI], 1.5-11.4) in a multivariate Cox regression model. In contrast, heterozygosity for the polymorphism was associated with an unaltered HR (HR, 1.1; 95% CI, 0.6-1.9) for recurrent VTE. CONCLUSIONS: Homozygosity for the S128R E-selectin allele appears to increase the risk for recurrent VTE several fold. If these findings are confirmed, this may represent a novel risk factor for recurrent VTE. These results also expand our knowledge on the association of this SNP with thrombotic disorders.
Assuntos
Selectina E/genética , Tromboembolia/genética , Trombose Venosa/genética , Adulto , Arginina , Feminino , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Recidiva , SerinaRESUMO
Asymmetrical dimethylarginine (ADMA) is an endogenous inhibitor of endothelial nitric oxide synthase, causes vasoconstriction, impairs cardiac function, and may predict cardiovascular risk. The prognostic value of plasma ADMA concentrations in acute vascular situations may be confounded by concomitant factors such as clot formation. In an effort to address the effect of hemostatic system activation, the authors have measured plasma concentrations of ADMA, its stereoisomer symmetrical dimethylarginine (SDMA), and L-arginine in 74 patients with suspected deep vein thrombosis (DVT). DVT was confirmed by sonography or venography in 39 subjects. There was no difference of L-arginine, ADMA, or SDMA (all P > 0.05) between subjects with or without DVT. ADMA correlated with SDMA, L-arginine, and plasma creatinine (all P < 0.05) but not with age, body mass index, D-dimer, thrombus extension, or history of symptoms. Venous thrombembolism does not influence circulating ADMA concentrations. The lack of association between ADMA and DVT argues against a contribution of endogenous NO synthase inhibition in hemostatic systemic activation.