RESUMO
Classification criteria for antiphospholipid syndrome (APS) require IgG or IgM isotypes of the anticardiolipin (aCL) antibodies, anti-ß2 glycoprotein I (anti-ß2GPI) antibodies, and/or the lupus anticoagulant (LA) to satisfy the laboratory disease definition. Over the past 20 years, non-criteria antiphospholipid antibodies (aPL) directed to other proteins of the coagulation cascade (i.e. prothrombin and/or phosphatidylserine-prothrombin complex) or to some domains of ß2GPI have been proposed. This task force concentrated and reviewed the literature on data including aPS/PT, antibodies to domain 4/5 of ß2GPI and the newly described antibodies to protein/HLA-DR complex. In addition, we discussed testing of LA in the 'new' oral anticoagulants' era and the value of triple positivity in the risk assessment of aPL. The conclusions were presented at a special session during the 16th International Congress on aPL, Manchester, UK, September 2019.
Assuntos
Síndrome Antifosfolipídica , Lúpus Eritematoso Sistêmico , Humanos , Protrombina , Anticorpos Antifosfolipídeos , Inibidor de Coagulação do Lúpus , Anticorpos Anticardiolipina , beta 2-Glicoproteína IRESUMO
OBJECTIVES: Risk factors for thromboembolism in SLE are poorly understood. We hypothesized a possible role for protein C, based on its dual activity in inflammation and haemostasis and on the evidence of an association between acquired activated protein C (APC) resistance (APCR) and high-avidity anti-protein C antibodies (anti-PC) with a severe thrombotic phenotype in venous thrombosis APS patients. METHODS: In a cross-sectional study of 156 SLE patients, the presence and avidity of IgG anti-PC was established by in house-ELISA, and APCR to exogenous recombinant human APC (rhAPC) and Protac (which activates endogenous protein C) was assessed by thrombin generation-based assays. Associations with aPL profile, thrombotic history and disease activity (BILAG and SLEDAI-2K) were also established. RESULTS: Anti-PC were detected in 54.5% of patients and APCR in 59%. Anti-PC positivity was associated with APCR to both rhAPC (P <0.0001) and Protac (P =0.0001). High-avidity anti-PC, detected in 26.3% of SLE patients, were associated with APCR in patients with thrombosis only (P <0.05), and with the development of thrombosis over time (range: 0-52 years; P =0.014). High-avidity anti-PC levels correlated with SLEDAI-2K (P =0.033) and total BILAG (P =0.019); SLEDAI-2K correlated inversely with APCR to Protac (P =0.004). CONCLUSION: Anti-PC occur in patients with SLE, independently of aPL profile, and are associated with APCR. High-avidity anti-PC are associated with thrombosis and with active disease and might prove a novel marker to monitor the risk of thrombosis and disease progression in SLE.
Assuntos
Resistência à Proteína C Ativada/imunologia , Autoanticorpos/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Proteína C/imunologia , Tromboembolia/imunologia , Resistência à Proteína C Ativada/sangue , Resistência à Proteína C Ativada/complicações , Resistência à Proteína C Ativada/etiologia , Biomarcadores/sangue , Estudos Transversais , Feminino , Humanos , Lúpus Eritematoso Sistêmico/complicações , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Trombina/metabolismo , Tromboembolia/etiologiaRESUMO
Coffee is rich in caffeine (CF), chlorogenic acid (CGA) and phenolics. Differing types of coffee beverages and brewing procedures may result in differences in total phenolic contents (TPC) and biological activities. Inflammation and increases of platelet activation and aggregation can lead to thrombosis. We focused on determining the chemical composition, antioxidant activity and inhibitory effects on agonist-induced platelet aggregation and cyclooxygenase (COX) of coffee beverages in relation to their preparation method. We prepared instant coffee and brewed coffee beverages using drip, espresso, and boiling techniques. Coffee extracts were assayed for their CF and CGA contents using HPLC, TPC using colorimetry, platelet aggregation with an aggregometer, and COX activity using ELISA. The findings have shown all coffee extracts, except the decaffeinated types, contained nearly equal amounts of CF, CGA, and TPC. Inhibitory effects of coffee extracts on platelet aggregation differed depending on the activation pathways induced by different agonists. All espresso, drip and boiled coffee extracts caused dose dependent inhibition of platelet aggregation induced by ADP, collagen, epinephrine, and arachidonic acid (ARA). The most marked inhibition was seen at low doses of collagen or ARA. Espresso and drip extracts inhibited collagen-induced platelet aggregation more than purified caffeine or CGA. Espresso, boiled and drip coffee extracts were also a more potent inhibitors of COX-1 and COX-2 than purified caffeine or CGA. We conclude that inhibition of platelet aggregation and COX-1 and COX-2 may contribute to anti-platelet and anti-inflammatory effects of espresso and drip coffee extracts.
Assuntos
Coffea/química , Café/química , Inibidores de Ciclo-Oxigenase/química , Inibidores de Ciclo-Oxigenase/farmacologia , Inibidores da Agregação Plaquetária/química , Inibidores da Agregação Plaquetária/farmacologia , Ácido Clorogênico/química , Ácido Clorogênico/farmacologia , Cromatografia Líquida de Alta Pressão , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Agregação Plaquetária/efeitos dos fármacosRESUMO
We respond to comments by Dufrost et al. about the RAPS trial, in particular, showing that the trial did achieve its target sample size; pointing out that thrombin potential is not synonymous with overall thrombin generation; confirming that overall, no increased thrombotic risk was evident comparing rivaroxaban with warfarin; and that high-risk patients (28% were triple positive, representative of patients with venous thromboembolism requiring standard-intensity anticoagulation) were included; and clarifying our rationale for using a laboratory surrogate primary outcome measure instead of a clinical one.
Assuntos
Síndrome Antifosfolipídica , Tromboembolia Venosa , Anticoagulantes , Humanos , Rivaroxabana , VarfarinaAssuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Complemento C5/antagonistas & inibidores , Inativadores do Complemento/uso terapêutico , Hemoglobinúria Paroxística/tratamento farmacológico , Proteínas Recombinantes/uso terapêutico , Adulto , Animais , Resistência a Medicamentos , Humanos , MasculinoRESUMO
Medical photographs are used in many clinical settings; however, there are significant risks associated with using the camera feature on mobile devices, namely, breaches of security. PicSafe Medi is an app that allows healthcare professionals to take clinical photographs using smart devices whilst addressing the concerns of patient confidentiality. We review the app to assess its functionality in a UK clinical setting, taking into account UK guidelines such as those offered by the General Medical Council, UK legislation, the Institute of Medical Illustrators and the Department of Health.
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Diagnóstico por Imagem , Software , Confidencialidade , Humanos , Consentimento Livre e Esclarecido , Software/economiaRESUMO
The quantification of residual plasmatic ADAMTS13 activity in congenital thrombotic thrombocytopenic purpura (TTP) patients is constrained by limitations in sensitivity and reproducibility of commonly used assays at low levels of ADAMTS13 activity, blunting efforts to establish genotype-phenotype correlations. In the present study, the residual plasmatic activity of ADAMTS13 was measured centrally by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (limit of detection = 0.5%) in 29 congenital TTP patients. The results were used to study correlations among ADAMTS13 genotype, residual plasmatic activity, and clinical phenotype severity. An ADAMTS13 activity above 0.5% was measured in 26 (90%) patients and lower levels of activity were associated with earlier age at first TTP episode requiring plasma infusion, more frequent recurrences, and prescription of fresh-frozen plasma prophylaxis. Receiver operating characteristic curve analysis showed that activity levels of less than 2.74% and 1.61% were discriminative of age at first TTP episode requiring plasma infusion < 18 years, annual rate of TTP episodes > 1, and use of prophylaxis. Mutations affecting the highly conserved N-terminal domains of the protein were associated with lower residual ADAMTS13 activity and a more severe phenotype in an allelic-dose dependent manner. The results of the present study show that residual ADAMTS13 activity is associated with the severity of clinical phenotype in congenital TTP and provide insights into genotype-phenotype correlations.
Assuntos
Proteínas ADAM/sangue , Proteínas ADAM/deficiência , Púrpura Trombocitopênica Trombótica/sangue , Púrpura Trombocitopênica Trombótica/congênito , Proteínas ADAM/genética , Proteína ADAMTS13 , Adolescente , Adulto , Fatores Etários , Idoso , Análise Química do Sangue , Transfusão de Sangue , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Plasma , Púrpura Trombocitopênica Trombótica/genética , Púrpura Trombocitopênica Trombótica/terapia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Adulto JovemRESUMO
This guidance was prepared on behalf of the International Council for Standardisation in Haematology (ICSH) by an international working group of clinicians and scientists. The document focuses on tests and assays used for the assessment of fibrinogen function, particularly in the scenario of bleeding disorders. Thrombin clotting time (TT) is used as a screening test in some laboratories and also has some utility when direct anticoagulants are in use. The Clauss fibrinogen assay remains the method of choice for the assessment of fibrinogen function, but there are some situations where the results may be misleading. Prothrombin time derived fibrinogen assays are frequently used, but should be interpreted with caution; the results are not interchangeable between different methods and fibrinogen can be overestimated in certain clinical scenarios. Viscoelastic point of care methods may be helpful in emergency situations, while Reptilase time (and similar tests) are useful combined with TT in distinguishing heparin contamination of samples (i.e., if an incorrect blood draw is suspected) and the presence of direct thrombin inhibitors. Fibrinogen antigen assays should be used in the investigation of functional fibrinogen abnormalities; fibrinogen antigen and genetic testing are recommended in the confirmation of congenital fibrinogen disorders. The following recommendations for fibrinogen function assessment are based on published literature and expert opinion and should supplement local regulations and standards.
Assuntos
Transtornos da Coagulação Sanguínea , Hematologia , Hemostáticos , Humanos , Tempo de Trombina , Trombina , Testes de Coagulação Sanguínea/métodos , Fibrinogênio/análiseRESUMO
We propose that porto-pulmonary hypertension (PPH) may arise as a consequence of deficiency of ADAMTS13 (a plasma metalloprotease that regulates von Willebrand factor size and reduces its platelet adhesive activity) and provide a clinical case history to support our hypothesis. A patient with non-cirrhotic intrahepatic portal hypertension (NCIPH), ulcerative colitis and celiac disease developed symptoms of PPH, which had advanced beyond levels which would have made her an eligible candidate for liver transplantation (mean pulmonary artery pressure (PAP) 49 mm Hg). She was known to have severe ADAMTS13 deficiency, which we considered to be causative of, or contributory to her NCIPH. We postulated that increasing porto-systemic shunting associated with advancing portal hypertension would make the next encountered vascular bed, the lung, susceptible to the pathogenic process that was previously confined to the portal system, with pulmonary hypertension as its consequence. Her pulmonary artery pressures fell significantly during the next year on weekly replacement of plasma ADAMTS13 by infusions of fresh frozen plasma and conventional drug treatment of her pulmonary hypertension. Her pulmonary artery pressures had fallen to acceptable levels when, in response to platelet infusion, it rose precipitously and dangerously. The sequence strongly supports our hypothesis that PPH is a consequence of ADAMTS13 deficiency and is caused by platelet deposition in afferent pulmonary vessels.
Assuntos
Proteínas ADAM/deficiência , Hipertensão Portal/sangue , Hipertensão Portal/etiologia , Hipertensão Pulmonar/sangue , Hipertensão Pulmonar/etiologia , Transfusão de Plaquetas/efeitos adversos , Proteínas ADAM/sangue , Proteína ADAMTS13 , Adulto , Pressão Arterial , Doença Celíaca/complicações , Colite Ulcerativa/complicações , Feminino , Insuficiência Cardíaca/etiologia , Humanos , Hipertensão Pulmonar/fisiopatologia , Disfunção Ventricular Direita/etiologia , Fator de von Willebrand/metabolismoRESUMO
This guideline has been written on behalf of the International Council for Standardisation in Haematology (ICSH) and focuses on two point of care haematology tests used within primary care, namely International Normalised Ratio (INR) and D-dimer. Primary care covers out of hospital settings and can include General Practice (GP), Pharmacy and other non-hospital settings (although these guidelines would also be applicable to hospital out-patient settings). The recommendations are based on published data in peer reviewed literature and expert opinion; they should supplement regional requirements, regulations or standards.
Assuntos
Testes Hematológicos , Testes Imediatos , Humanos , Coeficiente Internacional Normatizado , Atenção Primária à SaúdeRESUMO
OBJECTIVE: To characterize the interaction between procoagulant and/or anticoagulant serine proteases and human monoclonal IgG antiphospholipid antibodies (aPL) and polyclonal IgG derived from patients with the antiphospholipid syndrome (APS). METHODS: Five human monoclonal IgG with small differences in their sequences were tested for binding to protein C, activated protein C, plasmin, factor VIIa (FVIIa), FIX, FIXa, and FXII. Serum levels of antithrombin and anti-activated protein C were compared in 32 patients with APS, 29 patients with systemic lupus erythematosus (SLE), and 22 healthy controls. Purified polyclonal IgG derived from APS patients with elevated levels of serum antithrombin antibodies was also tested for its functional effects on thrombin and antithrombin activity. RESULTS: Studies of monoclonal antibodies showed that sequence changes in human aPL are important in determining their ability to bind procoagulant and anticoagulant/fibrinolytic serine proteases. Mean IgG antithrombin levels were significantly elevated in patients with APS and in SLE patients with aPL but no APS (SLE/aPL+) compared to healthy controls, but anti-activated protein C levels were not increased in these patients. Moreover, IgG purified from patients with APS displayed higher avidity for thrombin and significantly inhibited antithrombin inactivation of thrombin compared with IgG from SLE/aPL+ patients. CONCLUSION: High-avidity antithrombin antibodies, which prevent antithrombin inactivation of thrombin, distinguish patients with APS from SLE/aPL+ patients, and thus may contribute to the pathogenesis of vascular thrombosis in APS.
Assuntos
Anticorpos Antifosfolipídeos/imunologia , Anticorpos Monoclonais/imunologia , Síndrome Antifosfolipídica/imunologia , Hemostasia/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Serina Proteases/imunologia , Adulto , Feminino , Humanos , Masculino , Trombose/imunologiaRESUMO
INTRODUCTION: Wound infection following burn injury can be clinically challenging to manage. Its presence in a thermally compromised patient can detrimentally affect the ability of the wound to heal leading not only to wound progression but ultimately contribute to a large part of the economic health burden expenditure in the National Health Service. Despite meticulous wound care and infection control measures the colonisation of burn wounds by bacterial pathogens has and continues to be the case. There has been a growing interest in the use of antimicrobial applications when managing localised burn wound infections due to a constantly increasing number of antibiotic-resistant organisms. AIM: To survey which antimicrobial dressings are currently being used across UK burns services when managing localised pseudomonas wound infections. METHODS: We conducted a nationwide telephone survey of UK burns services during October 2019 to determine which topical antimicrobial agent was used to treat local pseudomonas burn wound infections. RESULTS: Six burns services (31.6%) used acetic acid-soaked dressings, one of which alternates acetic acid with sodium hypochlorite solution. Silver-based dressings were also used by six burns services (31.6%) - again, one department alternates silver-based dressings with sodium hypochlorite solution. Betadine-soaked, gauze-based dressings were used across five burns services (26.3%) and the remaining two burns services (10.5%) used sodium hypochlorite solution and non-medicated dressings respectively. CONCLUSION: We identified a significant difference in the UK burns services' approach to pseudomonas burn wound infections. Our literature review demonstrates that a daily dressing regime of 2.5-3% acetic acid is a well-tolerated treatment regime in burn patients and that it is in use in UK burns services. There are no current randomised controlled trials that evaluate the usage of acetic acid. The variation in usage suggests that there is scope for further study in order to develop evidence to generate a UK wide approach based on national standardised guidelines.
Assuntos
Anti-Infecciosos , Queimaduras , Infecções por Pseudomonas , Lesões dos Tecidos Moles , Infecção dos Ferimentos , Ácido Acético/uso terapêutico , Anti-Infecciosos/uso terapêutico , Bandagens , Queimaduras/tratamento farmacológico , Queimaduras/terapia , Humanos , Pseudomonas , Infecções por Pseudomonas/tratamento farmacológico , Prata/uso terapêutico , Hipoclorito de Sódio , Medicina Estatal , Reino Unido , Infecção dos Ferimentos/tratamento farmacológicoRESUMO
BACKGROUND: Severe coronavirus disease 2019 (COVID-19) is characterized by marked hypoxaemia and lung oedema, often accompanied by disordered blood coagulation and fibrinolytic systems, endothelial damage and intravascular fibrin deposition. PATIENTS/METHODS: We present a retrospective observational study of 104 patients admitted to hospital with COVID-19. Plasma samples were collected within 72 h of admission. In addition to routine coagulation and haematology testing, soluble thrombomodulin (sTM), thrombin-antithrombin (TAT), tissue plasminogen activator-plasminogen activator inhibitor 1 complex (tPAI-C) and plasmin-α2 antiplasmin complex (PIC) were performed by automated chemiluminescent enzyme immunoassays. RESULTS: Significantly higher levels of D-dimer, TAT, sTM and tPAI-C were observed in non-survivors compared to survivors. To confirm which parameters were independent risk factors for mortality, multiple logistic regression was performed on D-dimer, TAT. sTM, tPAI-C and PIC data. Only increasing sTM was significantly associated with mortality, with an odds ratio of 1.065 for each 1.0 TU/mL increment (95% CI 1.025-1.115). CONCLUSIONS: Of the haemostatic variables measured, sTM, which can be rapidly assayed, is the best independent predictor of mortality in patients hospitalized with COVID-19, and this suggests that endothelial dysfunction plays an important role in disease progression.
Assuntos
Transtornos da Coagulação Sanguínea , COVID-19 , Biomarcadores , Coagulação Sanguínea , Fibrinólise , Humanos , Ativador de Plasminogênio TecidualRESUMO
OBJECTIVES: The significance of antibodies directed against activated factor X (FXa) and thrombin (Thr) in patients with SLE and/or antiphospholipid syndrome (APS) is unknown. FXa and Thr are coregulated by antithrombin (AT) and activate complement. Therefore, we studied the ability of anti activated factor X (aFXa) and/or anti-(a)Thr IgG from patients with SLE±APS to modulate complement activation. METHODS: Patients with SLE±APS were selected on the basis of known aThr and/or aFXa IgG positivity, and the effects of affinity-purified aFXa/aThr IgG on FXa and Thr-mediated C3 and C5 activation were measured ±AT. Structural analyses of FXa and Thr and AT-FXa and AT-Thr complexes were analysed in conjunction with the in vitro ability of AT to regulate aFXa-FXa and aThr-Thr-mediated C3/C5 activation. RESULTS: Using affinity-purified IgG from n=14 patients, we found that aThr IgG increased Thr-mediated activation of C3 and C5, while aFXa IgG did not increase C3 or C5 activation. Structural analysis identified potential epitopes and predicted a higher likelihood of steric hindrance of AT on FXa by aFXa IgG compared with the AT-Thr-aThr IgG complex that was confirmed by in vitro studies. Longitudinal analysis of 58 patients with SLE (±APS) did not find a significant association between positivity for aFXa or aTHr IgG and C3 levels or disease activity, although there was a trend for patients positive for aFXa IgG alone or both aFXa and aThr IgG to have lower levels of C3 compared with aThr IgG alone during clinical visits. CONCLUSIONS: We propose a novel method of complement regulation in patients with SLE±APS whereby aFXa and aThr IgG may have differential effects on complement activation.
Assuntos
Síndrome Antifosfolipídica , Lúpus Eritematoso Sistêmico , Síndrome Antifosfolipídica/complicações , Proteínas do Sistema Complemento , Fator X , Humanos , Imunoglobulina G , Lúpus Eritematoso Sistêmico/tratamento farmacológico , TrombinaRESUMO
The guideline writing group was selected to be representative of UK-based medical experts. MEDLINE was systematically searched for publications in English up to the Summer of 2010 using key words platelet, platelet function testing and platelet aggregometry. Relevant references generated from initial papers and published guidelines/reviews were also examined. Meeting abstracts were not included. The writing group produced the draft guideline, which was subsequently revised and agreed by consensus. Further comment was made by members of the Haemostasis and Thrombosis Task Force of the British Committee for Standards in Haematology. The guideline was then reviewed by a sounding board of approximately 40 UK haematologists, the British Committee for Standards in Haematology (BCSH) and the British Society for Haematology Committee and comments incorporated where appropriate. Criteria used to quote levels and grades of evidence are as outlined in appendix 7 of the Procedure for Guidelines Commissioned by the BCSH [http://www.bcshguidelines.com/BCSH_PROCESS/EVIDENCE_LEVELS_AND_GRADES_OF_RECOMMENDATION/43_GRADE.html]. The objective of this guideline is to provide healthcare professionals with clear guidance on platelet function testing in patients with suspected bleeding disorders. The guidance may not be appropriate to patients receiving antiplatelet therapy and in all cases individual patient circumstances may dictate an alternative approach.
Assuntos
Transtornos Herdados da Coagulação Sanguínea/diagnóstico , Transtornos Plaquetários/diagnóstico , Coleta de Amostras Sanguíneas/métodos , Coleta de Amostras Sanguíneas/normas , Pré-Escolar , Humanos , Lactente , Agregação Plaquetária , Contagem de Plaquetas/métodos , Contagem de Plaquetas/normas , Testes de Função Plaquetária/métodos , Testes de Função Plaquetária/normasRESUMO
BACKGROUND: ADAMTS13 deficiency leading to excess ultralarge von Willebrand factor (VWF) multimers and platelet clumping is typically found in thrombotic thrombocytopenic purpura (a type of thrombotic microangiopathy). Idiopathic noncirrhotic intrahepatic portal hypertension (NCIPH) is a microangiopathy of portal venules associated with significant thrombocytopenia and predisposing gut disorders. AIM: To determine whether the portal microangiopathy in NCIPH is associated with ADAMTS13 deficiency. METHODS: Plasma levels of ADAMTS13, anti-ADAMTS13 antibodies, and VWF were compared between cases (NCIPH patients) and controls (with chronic liver diseases of other etiology) matched for severity of liver dysfunction. Eighteen NCIPH patients [median (range) MELD score 12 (7-25)] and 25 controls [MELD score 11 (4-26)] were studied. RESULTS: ADAMTS13 activity was reduced in all 18 NCIPH patients and significantly lower than controls (median, IQR: 12.5%, 5-25% and 59.0%, 44-84%, respectively, P<0.0001) [normal range for plasma ADAMTS13 activity (55-160%)]. ADAMTS13 activity was <5% in 5/18 NCIPH patients (28%) and 0/25 controls (P=0.009). ADAMTS13 antigen levels were also decreased. Sustained low ADAMTS13 levels were seen in four NCIPH patients over 6 weeks to 11 months (highest ADAMTS13 level in each patient: <5%, 6%, 6%, and 25%), despite two patients having MELD score 12. Although nine cases had low titer anti-ADAMTS13 antibodies, there was no significant difference between cases and controls. Abnormally large VWF multimers were observed in 4/11 NCIPH patients (36%) and in 0/22 controls (P=0.008). CONCLUSIONS: Sustained deficiency of ADAMTS13 appears characteristic of NCIPH, irrespective of severity of liver disease.
Assuntos
Proteínas ADAM/sangue , Proteínas ADAM/deficiência , Hipertensão Portal/sangue , Proteína ADAMTS13 , Adulto , Autoanticorpos/sangue , Estudos de Casos e Controles , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Adulto JovemRESUMO
BACKGROUND: The Sysmex CN-6500 is a new haemostasis analyser with an integrated immunoassay module that performs chemiluminescence enzyme assay (CLEIA) in addition to coagulation, turbidimetric, chromogenic and platelet aggregation tests. AIMS: To evaluate the analytical performance of the CN-6500 against the predicate device (Sysmex HISCL-800) for soluble thrombomodulin (TM), thrombin-antithrombin (TAT), tissue plasminogen activator/plasminogen activator inhibitor 1 complex (tPAI-C) and plasmin α2 plasmin inhibitor complex (PIC) assays. METHODS: Imprecision was assessed by testing two levels of quality control plasmas 10 times on 5 separate days. Comparability was studied in 230 plasmas from normal donors (n = 30), patients with suspected disseminated intravascular coagulation (DIC, n = 100), sepsis (n = 20) or liver disease (n = 20), lipaemic (n = 20), haemolysed (n = 20) and icteric samples (n = 20). Limit of detection, limit of quantitation and linearity were determined by testing serial dilutions of normal plasma. Sample carryover was assessed by testing samples with high and low normal levels of the analytes concerned. RESULTS: The CN-6500 performed 21 CLEIA tests per hour, while simultaneously performing coagulation tests. Acceptable between-run imprecision was obtained using commercial controls with normal and high activity for each analyte (%CV <4%), for all four assays. Excellent linearity was observed (slope 0.89-1.03; r2 >0.99) across the measurement range. The lower limits of detection and quantitation were as follows: TM <0.3/0.6 TU/ml, TAT >0.1/<0.2 ng/ml, PIC <0.004/<0.008 µg/ml and tPAI-C < 0.01/<0.1 ng/ml, respectively. All four assays showed excellent correlation between analysers and were unaffected by haemolysis, icterus or lipaemia. No carryover was observed. CONCLUSIONS: Our data demonstrate that the performance of the CLEIA assays on the CN-6500 is comparable to that of a stand-alone immunoassay analyser.
Assuntos
Testes de Coagulação Sanguínea/normas , Técnicas Imunoenzimáticas/métodos , Técnicas Imunoenzimáticas/normas , Medições Luminescentes/métodos , Medições Luminescentes/normas , Automação Laboratorial , Coagulação Sanguínea , Testes de Coagulação Sanguínea/instrumentação , Testes de Coagulação Sanguínea/métodos , Humanos , Técnicas Imunoenzimáticas/instrumentação , Medições Luminescentes/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Acquired activated protein C resistance (APCr) has been identified in antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE). OBJECTIVE: To assess agreement between the ST-Genesia® and CAT analysers in identifying APCr prevalence in APS/SLE patients, using three thrombin generation (TG) methods. METHODS: APCr was assessed with the ST-Genesia using STG-ThromboScreen and with the CAT using recombinant human activated protein C and Protac® in 105 APS, 53 SLE patients and 36 thrombotic controls. Agreement was expressed in % and by Cohen's kappa coefficient. RESULTS: APCr values were consistently lower with the ST-Genesia® compared to the CAT, using either method, in both APS and SLE patients. Agreement between the two analysers in identifying APS and SLE patients with APCr was poor (≤65.9%, ≤0.20) or fair (≤68.5%, ≥0.29), regardless of TG method, respectively; no agreement was observed in thrombotic controls. APCr with both the ST Genesia and the CAT using Protac®, but not the CAT using rhAPC, was significantly greater in triple antiphospholipid antibody (aPL) APS patients compared to double/single aPL patients (p < 0.04) and in thrombotic SLE patients compared to non-thrombotic SLE patients (p < 0.05). Notably, the ST-Genesia®, unlike the CAT, with either method, identified significantly greater APCr in pregnancy morbidity (median, confidence intervals; 36.9%, 21.9-49.0%) compared to thrombotic (45.7%, 39.6-55.5%) APS patients (p = 0.03). CONCLUSION: Despite the broadly similar methodology used by CAT and ST-Genesia®, agreement in APCr was poor/fair, with results not being interchangeable. This may reflect differences in the TG method, use of different reagents, and analyser data handling.
RESUMO
BACKGROUND AND OBJECTIVES: Burns of less than 10% total body surface area (TBSA) are common injuries in children under five years of age. The inflammatory response to burn injury is well recognised for burns greater than 20% TBSA but has not been described for smaller burns. The aim of this study was to describe the systemic response to burn injury in young children with small-area burns. METHODS: The Morbidity In Small Thermal Injury in Children study (MISTIC) was a multicentre prospective observational cohort study that recruited 625 patients under five years of age with burns of less than 10% TBSA over eighteen months across three sites in England. Prospectively collected data included physical observations and laboratory blood tests taken in hospital as part of routine care. Additional information was sourced from temperature recordings taken at home following discharge. RESULTS: Elevated temperatures were observed in children with scald or contact burns between 2-10% TBSA, with a peak on day one after burn followed by a fall over days four to seven after burn. No temperature rise was seen in children with burns of <2% TBSA. Higher temperature readings were associated with larger burn size, age under two years and male sex. Heart rate and C-Reactive Protein levels showed a peak on day three after burn. CONCLUSIONS: An identifiable systemic inflammatory response to small-area burns in young children is reported. This knowledge can be used to aid in the diagnosis of children with a burn injury who re-present with a pyrexia, and no other symptoms to indicate clinical infection.
Assuntos
Temperatura Corporal/fisiologia , Queimaduras/fisiopatologia , Febre/etiologia , Superfície Corporal , Unidades de Queimados/organização & administração , Unidades de Queimados/estatística & dados numéricos , Queimaduras/complicações , Queimaduras/epidemiologia , Pré-Escolar , Estudos de Coortes , Inglaterra/epidemiologia , Feminino , Febre/fisiopatologia , Humanos , Lactente , Tempo de Internação/estatística & dados numéricos , Masculino , Pediatria/métodos , Pediatria/estatística & dados numéricos , Estudos Prospectivos , Estudos RetrospectivosRESUMO
This guidance document has been prepared on behalf of the International Council for Standardisation in Haematology (ICSH). The aim of the document is to provide guidance and recommendations for collection of blood samples for coagulation tests in clinical laboratories throughout the world. The following processes will be covered: ordering tests, sample collection tube and anticoagulant, patient preparation, sample collection device, venous stasis before sample collection, order of draw when different sample types need to be collected, sample labelling, blood-to-anticoagulant ratio (tube filling) and influence of haematocrit. The following areas are excluded from this document, but are included in an associated ICSH document addressing processing of samples for coagulation tests in clinical laboratories: sample transport and primary tube sample stability; centrifugation; interfering substances including haemolysis, icterus and lipaemia; secondary aliquots-transport and storage; and preanalytical variables for platelet function testing. The recommendations are based on published data in peer-reviewed literature and expert opinion.