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1.
Semin Thromb Hemost ; 49(8): 833-839, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35728601

RESUMO

Unprovoked (or provoked by mild risk factors) venous thromboembolism (VTE) in young patients, VTE in uncommon sites, or cases of unexplained VTE recurrence may be positive for antiphospholipid antibodies (aPL) and thus may be diagnosed with antiphospholipid syndrome (APS). The evaluation of aPL is standardized using immunological tests for anticardiolipin and anti-ß2-glycoprotein I. The determination of functional antibodies (lupus anticoagulant) is less standardized, especially in patients on anticoagulant treatment. Patients positive for all the three tests are at high risk of recurrence, which, in turn, might lead to chronic obstruction of pulmonary vessels (chronic thromboembolic pulmonary hypertension). Randomized clinical trials have shown that triple-positive patients should be treated with vitamin K antagonists maintaining an international normalized ratio between 2 and 3. Whether patients with VTE and incomplete aPL profile can be treated with direct oral anticoagulants should be further investigated.


Assuntos
Síndrome Antifosfolipídica , Tromboembolia Venosa , Humanos , Síndrome Antifosfolipídica/complicações , Síndrome Antifosfolipídica/tratamento farmacológico , Síndrome Antifosfolipídica/diagnóstico , Tromboembolia Venosa/tratamento farmacológico , Tromboembolia Venosa/etiologia , Anticorpos Antifosfolipídeos , Anticoagulantes/efeitos adversos , Inibidor de Coagulação do Lúpus/uso terapêutico
2.
Medicine (Baltimore) ; 101(35): e30320, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36107602

RESUMO

INTRODUCTION: Breast cancer (BC) is the most diagnosed cancer worldwide. Multiple myeloma (MM) is a hematologic malignancy characterized by the overproduction of monoclonal antibodies in the bone marrow. Systemic lupus erythematosus (SLE) is distinguished by the aberrant activity of the immune system with heterogeneous clinical manifestations. The coexistence of more than one major illness in a patient can present a diagnostic challenge for clinical physicians, especially when the comorbid diseases share a similar clinical presentation. Herein, we report an unusual case of secondary synchronous diagnosis of MM and SLE after BC treatment. PATIENT CONCERNS: A 69-year-old female patient with breast cancer experienced severe skin itching and rashes on the face, anterior chest wall, back, and trunk for two days before admission. She had high levels of immunoglobulin and anti-nuclear antibodies; low levels of complements 3 and 4; positive anti-cardiolipin-IgM, anti-beta 2 glycoprotein-1 (anti-ß2GP1) antibodies, and lupus anticoagulant results at serological testing. DIAGNOSIS: The postoperative pathology report showed ductal carcinoma in situ in the right breast. SLE was confirmed based on the 2019 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) criteria. IgG-κ type multiple myeloma was confirmed by bone marrow biopsy, and the patient was synchronously diagnosed with SLE and MM after BC treatment. INTERVENTIONS: Glucocorticoids and immunosuppressive agents, including intravenous hydrocortisone (5 g every 8 hours) and oral hydroxychloroquine (Plaquenil) (200 mg twice daily) were administered to treat SLE. One capsule of thalidomide 50 mg was administered orally every night at bedtime for MM. OUTCOMES: The patient died two days later, shortly after the administration of drugs, due to multiple organ failures secondary to pneumonia and respiratory failure. CONCLUSION: This is a case of MM and SLE after BC treatment. The present challenge was the early detection and accurate diagnosis of the secondary major illnesses, as the clinical manifestations were similar and non-specific between these two diseases. Awareness and prompt recognition of the common clinical symptoms of SLE and MM should be considered by clinical physicians to avoid delayed diagnoses and facilitate early treatment for a better prognosis.


Assuntos
Neoplasias da Mama , Lúpus Eritematoso Sistêmico , Mieloma Múltiplo , Idoso , Anticorpos Monoclonais/uso terapêutico , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/terapia , Feminino , Glicoproteínas/uso terapêutico , Humanos , Hidrocortisona/uso terapêutico , Hidroxicloroquina/uso terapêutico , Imunoglobulina G/uso terapêutico , Imunoglobulina M/uso terapêutico , Imunossupressores/uso terapêutico , Inibidor de Coagulação do Lúpus/uso terapêutico , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Mieloma Múltiplo/complicações , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/terapia , Talidomida/uso terapêutico
3.
J Int Med Res ; 50(8): 3000605221115390, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35971316

RESUMO

We report the cases of two children who presented with autoimmune hemolytic anemia (AIHA) as an initial presentation of systemic lupus erythematosus (SLE). Both patients had a positive Coombs test, anemia, and an increased number of spherocytes in their blood smear. The patient in Case 1 presented with fever, urticarial erythema, facial paresis, AIHA, and leucopenia. Immunological screening revealed low complement protein levels and positive anti-nuclear antibody, anti-double-stranded DNA, and antiphospholipid antibody results. A further laboratory workup revealed a positive lupus anticoagulant (LA) result and low factor II levels. She was diagnosed with lupus anticoagulant hypoprothrombinemia syndrome (LAHPS) in addition to SLE. The patient in Case 2 presented with fever, butterfly rash, thyroid enlargement, leucopenia, and AIHA. She was diagnosed with SLE with thyroiditis. Both patients were started on combined immunosuppressive therapy, and both patients' clinical symptoms finally resolved. A literature review on childhood SLE showed that AIHA is common in patients with SLE. LAHPS is an uncommonly identified cause of bleeding in patients with SLE, and it must be considered when evaluating children with a positive LA result.


Assuntos
Anemia Hemolítica Autoimune , Síndrome Antifosfolipídica , Leucopenia , Lúpus Eritematoso Sistêmico , Trombocitopenia , Anemia Hemolítica Autoimune/complicações , Anemia Hemolítica Autoimune/diagnóstico , Criança , Feminino , Humanos , Leucopenia/etiologia , Inibidor de Coagulação do Lúpus/uso terapêutico , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/diagnóstico
4.
Sci Rep ; 10(1): 12221, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32699227

RESUMO

Functional tests for lupus anticoagulants (LA) as part of a thrombophilia workup are commonly performed in patients under anticoagulant therapy that may interfere with assay results. There is no consensus on how these tests should be assessed in patients on direct oral anticoagulants (DOACs). In this retrospective cohort study, we analysed data from patients with a history of thrombosis in whom dilute Russell viper venom time (dRVVT), LA-sensitive aPTT, and solid phase assays for antiphospholipid antibodies (aPL) were performed (n = 3,147, thereof 588 on rivaroxaban, 144 on apixaban, 1,179 on other anticoagulant drugs). The dRVVT ratio was correlated with rivaroxaban (r = 0.30, P < 10-4) but not with apixaban plasma levels. The LA-sensitive aPTT/aPTT ratio showed no correlation with DOAC levels. Correspondingly, the rate of patients with abnormal dRVVT test was significantly higher (P < 10-4) under rivaroxaban (88%) than in thrombosis patients without anticoagulant medication (6%), independent from their aPL plasma levels. No isolated positive results of functional LA testing in patients on anticoagulants could be confirmed in repeated testing after discontinuation of the medication (n = 40). These data indicate that rivaroxaban should be discontinued before functional LA testing is performed. However, viable interpretation of these tests appears to be less affected in patients on apixaban.


Assuntos
Anticoagulantes/uso terapêutico , Inibidor de Coagulação do Lúpus/uso terapêutico , Trombose/tratamento farmacológico , Administração Oral , Adulto , Anticorpos Antifosfolipídeos/uso terapêutico , Síndrome Antifosfolipídica/tratamento farmacológico , Coagulação Sanguínea/efeitos dos fármacos , Testes de Coagulação Sanguínea/métodos , Dabigatrana/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tempo de Tromboplastina Parcial/métodos , Tempo de Protrombina/métodos , Pirazóis/uso terapêutico , Piridonas/uso terapêutico , Estudos Retrospectivos , Rivaroxabana/uso terapêutico , Trombofilia/tratamento farmacológico
6.
Anesth Analg ; 128(6): 1089-1096, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31094773

RESUMO

BACKGROUND: Patients presenting for surgery may have isolated or combined prolonged activated partial thromboplastin time (aPTT) and/or prothrombin time (PT). In patients not receiving anticoagulants or with no identifiable cause for abnormal clot formation, a mixing study is performed. The index of circulating anticoagulant (ICA) has been used to predict the presence of an inhibitor, usually a lupus anticoagulant. METHODS: We retrospectively reviewed the results of mixing studies performed at Northwestern Memorial Hospital, between January 1, 2010 and February 29, 2012. We determined the number of samples that normalized or remained prolonged, the clotting factors associated with prolonged test results, and the presence of coagulation inhibitors. We calculated the ICA in the samples with prolonged aPTT and PT to determine its ability to predict a lupus anticoagulant. The primary comparison of interest was the diagnostic utility of the ICA at cutoff values of 11% for predicting the presence of lupus anticoagulant. RESULTS: There were 269 mixing studies performed: 131 samples with prolonged aPTT; 95 with prolonged PT; and 43 with both prolonged aPTT and prolonged PT. Of the samples with a prolonged aPTT, 55 of 131 (42%) normalized, 36 of 131 (27%) partially corrected, and 40 of 131 (31%) remained prolonged. Thirty-three of 95 samples (35%) with prolonged PT normalized, while 62 of 95 (65%) remained prolonged. Eight of 43 (19%) mixing studies of patients with prolonged PT and aPTT normalized; the aPTT normalized, but the PT remained prolonged in 17 of 43 (39%); the PT normalized, but the aPTT remained prolonged in 7 of 43 (16%); and both tests remained prolonged in 11 of 43 (26%) samples. Prolongations in the aPTT were primarily associated with low activities of CF XII, while the majority of the prolongations in PT were secondary to low activities in CF VII. Combined prolongations were secondary to deficiencies in both the intrinsic and extrinsic as well as the common pathways. An ICA >11% had 100% (95% CI, 59%-100%) sensitivity, 53% (95% CI, 35%-70%) specificity, and 77% (95% CI, 62%-92%) accuracy in predicting the presence of lupus anticoagulant in patients with prolonged aPTT. CONCLUSIONS: Normalization of the aPTT and PT in a mixing study was associated with low clotting factor activity. The ICA may be helpful in predicting the presence of a lupus anticoagulant. As anesthesiologists take ownership of the perioperative surgical home, we need to understand the clinical implications of the results of mixing studies.


Assuntos
Testes de Coagulação Sanguínea/métodos , Coagulação Sanguínea/efeitos dos fármacos , Tempo de Tromboplastina Parcial , Tempo de Protrombina , Adulto , Idoso , Anticoagulantes/administração & dosagem , Anticoagulantes/farmacologia , Transtornos da Coagulação Sanguínea , Fatores de Coagulação Sanguínea/farmacologia , Feminino , Humanos , Inibidor de Coagulação do Lúpus/uso terapêutico , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Risco , Trombose/prevenção & controle
7.
Thromb Res ; 165: 101-106, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29627719

RESUMO

OBJECTIVE: Determination of lupus anticoagulants (LA) is an important, but still challenging test in the diagnosis of antiphospholipid syndrome (APS). This is especially the case in patients using one of the direct oral anticoagulants (DOACs). The aim of our study was to examine the influence of these drugs on DRVVT assays from two companies (in each case: screening test, confirming test and calculated ratio) and on aPTT and lupus-sensitive aPTT. METHODS: We used plasma samples from healthy volunteers spiked with the DOACs dabigatran, rivaroxaban and apixaban (0, 10, 30, 50, 100 ng/mL) for testing. Furthermore, samples from patients receiving a DOAC were investigated. The plasma concentrations of the DOACs were determined using ultra-performance liquid chromatography/electrospray ionization-tandem mass spectrometry (UPLC-MS/MS). RESULTS: Depending on type and concentration, all the DOACs resulted in pathological values in the DRVVT screening assays. In samples spiked with apixaban, no influence on the DRVVT normalized ratio of the two assays was observed, but 7 to 15% of samples from patients receiving apixaban displayed pathological values. In contrast, up to 71% of dabigatran-spiked samples showed normalized ratio values above the cut-off, whereas there was no influence in the patients' samples. In both spiked and patient samples containing rivaroxaban, the DRVVT assays were influenced. CONCLUSION: LA diagnostics should, under DOAC therapy, be limited to situations in which time-critical evaluation is warranted. It is crucial to take into account the finding that even samples containing DOAC concentrations below the limit of detection of the drugs may lead to false-positive DRVVT measurements.


Assuntos
Anticoagulantes/uso terapêutico , Testes de Coagulação Sanguínea/métodos , Inibidor de Coagulação do Lúpus/uso terapêutico , Administração Oral , Anticoagulantes/farmacologia , Feminino , Humanos , Inibidor de Coagulação do Lúpus/farmacologia , Masculino
8.
Autoimmun Rev ; 16(2): 173-178, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27988438

RESUMO

Lupus anticoagulant (LAC) is an in vitro phenomenon determining a phospholipid-dependent elongation of clotting times. The presence of LAC associated with anticardiolipin (aCL) and anti-ß2 glycoprotein I (anti-ß2GPI) antibodies is strongly associated with thrombosis and pregnancy morbidity. Direct oral anticoagulants (DOACs) targeting thrombin and factor Xa are currently widely use to prevent and treat venous and arterial thromboembolism. Some concern has, however, been expressed about the possibility of false laboratory results during LAC assessment in patients taking these drugs. Several in vitro studies, spiking DOACs into normal plasma as well as ex vivo at peak levels in treated patients, led in false-positive LAC. The dilute Russell Viper Venom time is the assay that is most influenced by rivaroxaban, edoxaban, dabigatran and less by apixaban. Both screening and confirmatory tests have resulted equally prolonged for activated partial thromboplastin time and have not led to false-positive results, but this may depend on the type of reagent used for the test. Taipan/Ecarin snake venoms ratios, has been recommend by some investigators as they do not seem to be affected by rivaroxaban or edoxaban, but these tests are neither standardized nor generally available in clinical practice. In conclusion, for the time being it does not seem advisable to carry out LAC testing during anti-factor Xa and anti-factor IIa treatment because of the risk of false-positive results. Whenever needed in deciding the suspension of DOACs or in case of recurrent thrombosis, LAC determination should be carried out at trough better if DOAC concentration is known.


Assuntos
Anticoagulantes/uso terapêutico , Síndrome Antifosfolipídica/tratamento farmacológico , Síndrome Antifosfolipídica/imunologia , Dabigatrana/uso terapêutico , Inibidor de Coagulação do Lúpus/uso terapêutico , Rivaroxabana/uso terapêutico , Administração Oral , Dabigatrana/administração & dosagem , Humanos , Inibidor de Coagulação do Lúpus/administração & dosagem , Rivaroxabana/administração & dosagem
9.
Oncotarget ; 7(37): 59965-59975, 2016 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-27494868

RESUMO

Strategies to target nanoparticles to tumors that rely on surface modification with ligands that bind molecules overexpressed on cancer cells or the tumor neovasculature suffer from a major limitation: with delivery of toxic agents the amount of molecules available for targeting decreases with time; consequently, the efficiency of nanoparticle delivery is reduced. To overcome this limitation, here we propose an autocatalytic tumor-targeting mechanism based on targeting extracellular DNA (exDNA). exDNA is enriched in the tumor microenviroment and increases with treatment with cytotoxic agents, such as doxorubicin (DOX), due to release of DNA by dying tumor cells. We tested this approach using poly(lactic-co-glycolic acid) (PLGA) nanoparticles surface-conjugated with fragments of 3E10 (3E10EN), a lupus anti-DNA autoantibody. We demonstrated that 3E10EN-conjugated nanoparticles bound to DNA and preferentially localized to tumors in vivo. The efficiency of tumor localization of 3E10EN-conjugated, DOX-loaded nanoparticles increased with time and subsequent treatments, demonstrating an autocatalytic effect. 3E10EN-conjugated DOX-loaded nanoparticles exhibited a significant anti-tumor effect that was superior to all controls. This work demonstrates the promise of autocatalytic drug delivery mechanisms and establishes proof of concept for a new anti-DNA autoantibody-based approach for enhancing delivery of nanoparticles to tumors.


Assuntos
Anticorpos Antinucleares/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/uso terapêutico , Inibidor de Coagulação do Lúpus/uso terapêutico , Neoplasias Mamárias Animais/tratamento farmacológico , Animais , Anticorpos Antinucleares/química , Anticorpos Catalíticos , Linhagem Celular Tumoral , DNA/análise , Doxorrubicina/química , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Ácido Láctico/química , Inibidor de Coagulação do Lúpus/química , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Microambiente Tumoral
10.
Lupus ; 24(12): 1338-41, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26014099

RESUMO

This present case pertains to a 48-year-old woman with a history of antiphospholipid syndrome, who presented with progressive fatigue, generalized weakness, and orthopnea acutely. She had a prior diagnosis of antiphospholipid syndrome with recurrent deep vein thromboses (DVTs) and repeated demonstration of lupus anticoagulants. She presented in cardiogenic shock with markedly elevated troponin and global myocardial dysfunction on echocardiography, and cardiac catheterization revealed minimal disease. Cardiac magnetic resonance imaging was performed, which revealed findings of perfusion defects and microvascular obstruction, consistent with the pathophysiology of catastrophic antiphospholipid syndrome (CAPS). Diagnosis was made based on supportive imaging, including head magnetic resonance imaging (MRI) revealing multifocal, acute strokes; microvascular thrombosis in the dermis; and subacute renal infarctions. The patient was anticoagulated with intravenous unfractionated heparin and received high-dose methylprednisolone, plasmapheresis, intravenous immunoglobulin, and one dose each of rituximab and cyclophosphamide. She convalesced with eventual myocardial recovery after a complicated course. The diagnosis of CAPS relies on the presence of (1) antiphospholipid antibodies and (2) involvement of multiple organs in a microangiopathic thrombotic process with a close temporal association. The myocardium is frequently affected, and heart failure, either as the presenting symptom or cause of death, is common. Despite echocardiographic evidence of myocardial dysfunction in such patients, MRIs of CAPS have not previously been reported. This case highlights the utility in assessing the involvement of the myocardium by the microangiopathic process with MRI. Because the diagnosis of CAPS requires involvement in multiple organ systems, cardiac MRI is likely an underused tool that not only reaffirms the pathophysiology of CAPS, but could also clue clinicians in to the possibility of a diffuse thrombotic process.


Assuntos
Anticorpos Antifosfolipídeos/sangue , Síndrome Antifosfolipídica/complicações , Nefropatias/etiologia , Choque Cardiogênico/etiologia , Trombose Venosa/etiologia , Síndrome Antifosfolipídica/diagnóstico , Doença Catastrófica , Feminino , Heparina/uso terapêutico , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Inibidor de Coagulação do Lúpus/uso terapêutico , Imageamento por Ressonância Magnética , Metilprednisolona/uso terapêutico , Pessoa de Meia-Idade , Plasmaferese
12.
Blood Coagul Fibrinolysis ; 25(5): 507-11, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24553060

RESUMO

Phlegmasia cerulea dolens (PCD) is an aggressive and life-threatening form of venous thrombosis complicated by ischemic necrosis. Massive thrombosis extends to collateral veins resulting in venous congestion with fluid sequestration in the interstitium causing collapse of arterioles, which progresses to ischemia and, if severe, circulatory collapse and shock. The mortality rate for PCD is as high as 40%, especially when gangrene develops. PCD has been associated with acquired thrombophilias, including malignancy and antiphospholipid syndrome (APS). We present a unique case of a patient with PCD refractory to anticoagulant and thrombolytic therapy, whose fulminant course was attributed to concurrent cholangiocarcinoma and antiphospholipid antibodies identified by a positive lupus anticoagulant assay. This case highlights the importance of uncovering precipitating causes of thromboembolism, which may offer prognostic information and may necessitate therapy beyond anticoagulation and thrombolysis to reduce the morbidity of PCD. The current literature on PCD and APS, along with their associations with malignancy, is reviewed.


Assuntos
Colangiocarcinoma/etiologia , Gangrena/complicações , Inibidor de Coagulação do Lúpus/uso terapêutico , Tromboflebite/complicações , Colangiocarcinoma/patologia , Gangrena/diagnóstico , Gangrena/patologia , Humanos , Inibidor de Coagulação do Lúpus/administração & dosagem , Masculino , Pessoa de Meia-Idade , Tromboflebite/diagnóstico , Tromboflebite/patologia
14.
Blood ; 119(11): 2624-32, 2012 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-22147897

RESUMO

The incidence of thrombosis in the purely obstetric form of antiphospholipid syndrome is uncertain. We performed a 10-year observational study of 1592 nonthrombotic women who had experienced 3 consecutive spontaneous abortions before the 10th week of gestation or 1 fetal death at or beyond the 10th week of gestation. We compared the frequencies of thrombotic events among women positive for antiphospholipid Abs (n = 517), women carrying the F5 6025 or F2 rs1799963 polymorphism (n = 279), and women with negative thrombophilia screening results (n = 796). The annual rates of deep vein thrombosis (1.46%; range, 1.15%-1.82%), pulmonary embolism (0.43%; range, 0.26%-0.66%), superficial vein thrombosis (0.44%; range, 0.28%-0.68%), and cerebrovascular events (0.32%; range, 0.18%-0.53%) were significantly higher in aPLAbs women than in the other groups despite low-dose aspirin primary prophylaxis. Women carrying 1 of the 2 polymorphisms did not experience more thrombotic events than women who screened negative for thrombophilia. Lupus anticoagulant was a risk factor for unprovoked proximal and distal deep and superficial vein thrombosis and women in the upper quartile of lupus anticoagulant activity had the highest risk. Despite data suggesting that aPLAbs may induce pregnancy loss through nonthrombotic mechanisms, women with purely obstetric antiphospholipid syndrome are at risk for thrombotic complications.


Assuntos
Aborto Espontâneo/epidemiologia , Síndrome Antifosfolipídica/epidemiologia , Fator V/genética , Polimorfismo Genético/genética , Complicações na Gravidez/epidemiologia , Protrombina/genética , Trombose/epidemiologia , Aborto Espontâneo/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antifosfolipídeos/sangue , Síndrome Antifosfolipídica/complicações , Síndrome Antifosfolipídica/genética , Feminino , Seguimentos , França/epidemiologia , Humanos , Incidência , Inibidor de Coagulação do Lúpus/uso terapêutico , Masculino , Pessoa de Meia-Idade , Gravidez , Complicações na Gravidez/etiologia , Estudos Prospectivos , Fatores de Risco , Trombofilia/epidemiologia , Trombofilia/etiologia , Trombose/etiologia , Trombose Venosa/epidemiologia , Trombose Venosa/etiologia , Adulto Jovem
15.
Thromb Res ; 127(6): 589-94, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21356545

RESUMO

BACKGROUND: Results for lupus anticoagulant (LA) are currently expressed as ratio of patient-to-normal clotting times (LA-ratio). Yet, numerical results do vary according to the method used for testing, thus making difficult the between-method comparison of results. We hypothesized that the standardization model currently used for the INR for patients on oral-anticoagulants (OAT) would be of value also for LA standardization. PATIENTS AND METHODS: To test this hypothesis we determined a sensitivity index valid for LA (called LASI) for six LA-detection methods against a common-standard using two sets of calibration-plasmas: (i)normal-plasmas spiked with IgG derived from patients strongly-positive for LA or (ii)plasmas from LA-positive patients. The LASI was then used to convert the LA-ratio into the standardized-LA-ratio (SLA-ratio) according to the equation: SLA-ratio = (LA-ratio)(LASI). RESULTS: We demonstrate that (i)the model is feasible because calibration plots of log-transformed clotting times obtained for the LA-detection methods-vs.-the common-standard gave acceptable LASI values; (ii)the model is effective because between-method variability expressed as coefficient of variation, which was 42.8% with results expressed as LA-ratio, decreased to 7.8% with results expressed as SLA-ratio; (iii)the LASI value calculated with the LA-positive plasmas is more effective in minimizing between-method variability than the LASI value calculated with IgG-spiked plasmas. CONCLUSIONS: A model of LA calibration similar to the INR for patients on OAT is feasible by using plasmas from LA-positive patients instead of patients on OAT. Potential application of the model are:(i)to compare the relative responsiveness of different LA-detection methods,(ii)to minimize differences between their results and (iii)to quantify LA potency.


Assuntos
Testes de Coagulação Sanguínea/normas , Inibidor de Coagulação do Lúpus/uso terapêutico , Calibragem , Estudos de Viabilidade , Humanos , Coeficiente Internacional Normatizado/normas , Padrões de Referência , Reprodutibilidade dos Testes
16.
J Thromb Haemost ; 9(4): 738-47, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21255251

RESUMO

BACKGROUND: Patients with antiphospholipid syndrome (APS) display a heterogeneous population of antibodies with beta(2) glycoprotein-1 (ß(2)GP1) as the major antigen. OBJECTIVES: We isolated and characterized human mAbs directed against ß(2)GP1 from the immune repertoire of APS patients. METHODS: Variable heavy chain repertoires from B cells from two APS patients with anti-ß(2)GP1 antibodies were cloned into the pHEN1-VLrep vector. Constructed full-length IgG antibodies were tested for lupus anticoagulant (LAC) activity and binding to ß(2)GP1 and its domains. RESULTS: Two clones of each patient were selected on the basis of the reactivity of single chain Fv (scFv) fragments displayed on phages towards full-length ß(2)GP1 and its isolated domain I. The affinity of selected antibodies for ß(2)GP1 was lost when transforming from phages to monovalent scFvs, and was regained when antibodies were constructed as complete IgG, indicating a role for bivalency in binding to ß(2)GP1. Both selected clones from patient 2 recognized domain I of ß(2)GP1, and for both clones selected from patient 1, binding required the presence of both domain I and domain II. All mAbs displayed LAC activity in both activated partial thromboplastin time-based and dilute Russell's viper venom test-based clotting assays and in thrombin generation. CONCLUSIONS: In this study, we show successful cloning of patient-derived mAbs that require domain I of ß(2)GP1 for binding, and that display LAC activity that is dependent on their affinity for ß(2)GP1. These antibodies can help us to gain more insights into the pathogenesis of APS, and may facilitate standardization of APS diagnosis.


Assuntos
Anticorpos Monoclonais/imunologia , Inibidor de Coagulação do Lúpus/uso terapêutico , beta 2-Glicoproteína I/imunologia , beta 2-Glicoproteína I/uso terapêutico , Sequência de Aminoácidos , Anticorpos Monoclonais/química , Ensaio de Imunoadsorção Enzimática , Humanos , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos
17.
Harefuah ; 149(5): 288-90, 336, 2010 May.
Artigo em Hebraico | MEDLINE | ID: mdl-20941871

RESUMO

Lupus anticoagulants (LAC) are antibodies which are detected by a prolongation of phospholipid-dependent coagulation assays, and are associated with thrombotic events and pregnancy complications in patients with the antiphospholipid syndrome. The antiphospholipid syndrome is defined by arterial or venous thrombosis and/or pregnancy morbidity and by laboratory diagnosis of antiphospholipid antibodies. The laboratory diagnosis is based on LAC and/or anticardiolipin and/or anti-beta2-glycoprotein I antibodies present in plasma, on two or more occasions at least 12 weeks apart. ALthough the presence of LAC correlates best with thrombosis, the Laboratory testing of LAC is not well standardized. In this article, the Laboratory evaluation of LAC will be explained, including the different tests that are recommended by the Israeli Sub-committee of Thrombosis and Hemostasis Laboratories, the possibility to evaluate LAC in patients treated with antithrombotic therapy, and how to report and interpret the results.


Assuntos
Anticorpos Antifosfolipídeos/sangue , Inibidor de Coagulação do Lúpus/uso terapêutico , Síndrome Antifosfolipídica/tratamento farmacológico , Coagulação Sanguínea/efeitos dos fármacos , Técnicas de Laboratório Clínico , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Fatores Imunológicos/efeitos adversos , Fatores Imunológicos/uso terapêutico , Israel , Inibidor de Coagulação do Lúpus/efeitos adversos , Inibidor de Coagulação do Lúpus/análise , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/imunologia , Trombose Venosa/tratamento farmacológico
18.
Blood Coagul Fibrinolysis ; 21(3): 242-4, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20182349

RESUMO

Warfarin therapy is used in lupus anticoagulant patients with thrombosis and yet the prothrombin time (PT)/international normalized ratio (INR) in these patients can sometimes be falsely elevated. Both a PT-based factor II (FII) assay and a chromogenic, enzymatic factor X (CFX) assay have been used for monitoring when the INR may be artifactual. This study compared FII and CFX assays in lupus anticoagulant-positive and lupus anticoagulant-negative warfarin-treated patients in a cross-sectional study of samples from 21 lupus anticoagulant-positive and 19 lupus anticoagulant-negative outpatients. Plasma samples were simultaneously measured for FII and CFX and the ratio of FII/CFX was used to measure concordance. Compared with lupus anticoagulant-negative patients 14 of the 21 lupus anticoagulant-positive patients had lower FII/CFX ratios (P < 0.01). Three of the patients had ratios less than 0.6 indicating strong disagreement (P < 0.0001). The patient with the lowest FII/CFX ratio had evidence suggesting a specific antibody to FII. Another patient showed that the discordance between FII and CFX varied over time. The CFX assay in the laboratory was technically superior, more precise, and less costly. The CFX assay is preferred for warfarin therapy monitoring in lupus anticoagulant patients when INR artifacts are suspected.


Assuntos
Anticoagulantes/uso terapêutico , Fator X/metabolismo , Inibidor de Coagulação do Lúpus/uso terapêutico , Protrombina/metabolismo , Trombose/tratamento farmacológico , Varfarina/uso terapêutico , Estudos Transversais , Humanos
19.
Rev. chil. obstet. ginecol ; 66(5): 371-376, 2001. tab
Artigo em Espanhol | LILACS | ID: lil-313258

RESUMO

En el período de julio de 1988 a agosto de 2000 se atendieron 23 pacientes lúpicas con 24 embarazos en la Maternidad del Barros Luco-Trudeau: la edad fluctuó entre los 18 y 41 años con una mediana de 23 años, 13 (56,5 por ciento) correspondieron a primíparas y 10 (43,5 por ciento) a multíparas. La edad promedio al diagnóstico de lupus fue 21 años. Hubo 8 embarazos con lupus activo en 4 de los cuales el lupus debutó en éste. No hubo actividad lúpica durante el puerperio, presentándose 3 casos en el primer trimestre, 3 en el segundo y 2 en el tercero. Hubo 20 partos de pretérmino (83,3 por ciento) y 7 casos de RCIU (29,1 por ciento). El 58,3 por ciento de los recién nacidos pesaron menos de 2500 g, hubo un 16,6 por ciento de letalidad perinatal (4 casos) y el 75 por ciento de los embarazos se resolvieron en cesárea


Assuntos
Humanos , Feminino , Gravidez , Recém-Nascido , Adulto , Pessoa de Meia-Idade , Lúpus Eritematoso Sistêmico/diagnóstico , Complicações na Gravidez , Retardo do Crescimento Fetal , Recém-Nascido de Baixo Peso , Recém-Nascido Prematuro , Inibidor de Coagulação do Lúpus/uso terapêutico , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/etiologia
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