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1.
Adv Clin Chem ; 93: 239-262, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31655731

RESUMO

Current guidelines worldwide recommend cardiac troponins I (cTnI) and T (cTnT) as the biomarkers of choice for the differential diagnosis of acute coronary syndrome (ACS), and the measurement of the 99th upper reference population limit (URL) value for cardiac troponins, with an imprecision of ≤10 CV%. Measuring the 99th URL of cTnI and cTnT is a challenging analytical task due to low biomarker concentrations present in healthy subjects. Therefore, since the year 2006, several manufacturers have established new generation cTnI and cTnT immunoassays with an improved analytical sensitivity in accordance with the quality specifications described in international guidelines, the more recent of which state that only immunoassays that meet the required quality specifications should be considered "high-sensitivity" methods. For the early diagnosis of ACS, and for the stratification of cardiovascular risk in cardiac patients and the general population, high-sensitivity methods should be employed. It is therefore important for laboratory professionals and clinicians to gain a thorough understanding of the analytical performances of immunoassay methods for cTnI and cTnT, especially at low to normal concentration ranges. The aim of the present study was to analyze critical aspects related to definition, analytical performance, pathophysiological interpretations, and the clinical relevance of high-sensitivity cardiac troponin assays.


Assuntos
Síndrome Coronariana Aguda/sangue , Imunoensaio/métodos , Troponina I/sangue , Troponina T/sangue , Síndrome Coronariana Aguda/diagnóstico , Biomarcadores/sangue , Diagnóstico Precoce , Feminino , Humanos , Masculino , Sensibilidade e Especificidade
3.
Clin Chim Acta ; 496: 25-34, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31201817

RESUMO

BACKGROUND: The study aim is to compare cTnI values measured with three high-sensitivity (hs) methods in apparently healthy volunteers and patients admitted to emergency department (ED) with acute coronary syndrome enrolled in a large multicentre study. METHODS: Heparinized plasma samples were collected from 1511 apparently healthy subjects from 8 Italian clinical institutions (mean age: 51.5 years, SD: 14.1 years, range: 18-65 years, F/M ratio:0.95). All volunteers denied chronic or acute diseases and had normal values of routine laboratory tests. Moreover, 1322 heparinized plasma sample were also collected by 9 Italian clinical institutions from patients admitted to ED with clinical symptoms typical of acute coronary syndrome. The reference study laboratory assayed all plasma samples with three hs-methods: Architect hs-cTnI, Access hs-cTnI and ADVIA Centaur XPT methods. Principal Component Analysis (PCA) was also used to analyze the between-method differences among hs-cTnI assays. RESULTS: On average, a between-method difference of 31.2% CV was found among the results of hs-cTnI immunoassays. ADVIA Centaur XPT method measured higher cTnI values than Architect and Access methods. Moreover, 99th percentile URL values depended not only on age and sex of reference population, but also on the statistical approach used for calculation (robust non-parametric vs bootstrap). CONCLUSIONS: Due to differences in concentrations and reference values, clinicians should be advised that plasma samples of the same patient should be measured for cTnI assay in the same laboratory. Specific clinical studies are needed to establish the most appropriate statistical approach to calculate the 99th percentile URL values for hs-cTnI methods.


Assuntos
Síndrome Coronariana Aguda/sangue , Análise Química do Sangue/métodos , Serviço Hospitalar de Emergência , Voluntários Saudáveis , Limite de Detecção , Miocárdio/metabolismo , Troponina I/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise Química do Sangue/normas , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Admissão do Paciente , Valores de Referência , Adulto Jovem
5.
Clin Chim Acta ; 495: 161-166, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30978328

RESUMO

BACKGROUND: According to quality specifications required by international guidelines, the evaluation of the 99th URL value is a very difficult task that is usually beyond the capacity of a single laboratory. The aims of this article are to report and discuss the results of a multicenter study concerning the evaluation of the 99th percentile URL and reference change (RCV) of the ADVIA Centaur High-Sensitivity Troponin I (TNIH), recently distributed to the Italian clinical laboratories. MATERIALS AND METHODS: The reference population evaluated with ADVIA XPT method for the calculation of cTnI reference distribution parameters consisted of 1325 healthy adults subjects (age range from 18 to 86 years), including 653 women (mean age 50.7 years, SD 14.5 years) and 672 men (mean age 50.9 years, SD 13.8 years), well matched for both age (P = .8112) and sex (F/M = 0.97). RESULTS: cTnI distribution values of reference population was highly skewed, while log-transformed cTnI values roughly approximated a log-normal distribution. Men have higher cTnI values than women throughout all the adult lifespan. Moreover, the subjects with age ≤ 55 years had significantly lower cTnI values than those with age > 55 years (p < .0001). Of note, 62% of women and 77% of men had equal or higher than cTnI values than the LoD value of the method (i.e., 2.2 ng/L). CONCLUSIONS: The results of the present study demonstrate that the ADVIA Centaur High-Sensitivity Troponin I using the XPT automated platform fits both the criteria and quality specifications required by the most recent international guidelines for high-sensitivity methods for cTnI assay.


Assuntos
Análise Química do Sangue/normas , Miocárdio/metabolismo , Troponina I/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imunoensaio/normas , Masculino , Pessoa de Meia-Idade , Valores de Referência , Troponina I/metabolismo , Adulto Jovem
8.
Clin Chim Acta ; 493: 156-161, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30826369

RESUMO

BACKGROUND: The Italian Society of Clinical Biochemistry (SIBioC) and the Italian Section of the European Ligand Assay Society (ELAS) have recently promoted a multicenter study (Italian hs-cTnI Study) with the aim to accurately evaluate analytical performances and reference values of the most popular cTnI methods commercially available in Italy. The aim of this article is to report the results of the Italian hs-cTnI Study concerning the evaluation of the 99th percentile URL and reference change (RCV) values around the 99th URL of the Access cTnI method. MATERIALS AND METHODS: Heparinized plasma samples were collected from 1306 healthy adult volunteers by 8 Italian clinical centers. Every center collected from 50 to 150 plasma samples from healthy adult subjects. All volunteers denied the presence of chronic or acute diseases and had normal values of routine laboratory tests (including creatinine, electrolytes, glucose and blood counts). An older cohort of 457 adult subjects (mean age 63.0 years; SD 8.1 years, minimum 47 years, maximum 86 years) underwent also ECG and cardiac imaging analysis in order to exclude the presence of asymptomatic cardiac disease. RESULTS AND CONCLUSIONS: The results of the present study confirm that the Access hsTnI method using the DxI platform satisfies the two criteria required by international guidelines for high-sensitivity methods for cTn assay. Furthermore, the results of this study confirm that the calculation of the 99th percentile URL values are greatly affected not only by age and sex of the reference population, but also by the statistical approach used for calculation of cTnI distribution parameters.


Assuntos
Técnicas de Imagem de Sincronização Cardíaca/normas , Eletrocardiografia/normas , Troponina I/sangue , Troponina T/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Voluntários Saudáveis , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Valores de Referência , Adulto Jovem
10.
Clin Chem Lab Med ; 57(6): 911-917, 2019 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-30412461

RESUMO

Background The study aim was to evaluate and compare analytical performances and clinical results of ADVIA BNP and PBNP methods using the Centaur XPT platform with those of Access BNP, using the DxI platform and the ECLIA NT-proBNP method, using the Cobas e411 platform, respectively. Methods Limits of blank (LoB), detection (LoD) and quantitation (LoQ) at 20% CV and 10% CV were evaluated according to international standardized protocols. The analytical parameters were assessed throughout a 90-working-day period using three curve calibrations. Results LoB, LoD and LoQ at 20% CV and 10% values of the ADVIA BNP method were 1.0 ng/L, 2.0 ng/L, 3.7 ng/L and 10.2 ng/L, respectively; while those of the ADVIA PBNP method were 1.3 ng/L, 3.0 ng/L, 9.7 ng/L and 22.3 ng/L, respectively. The ADVIA BNP and PBNP methods were able to measure the clinical decision values suggested by international guidelines for diagnosis of heart failure (HF) with an imprecision ≤6%. BNP concentrations measured with the ADVIA and Access methods showed a close linear regression (R=0.9923, n=200); a close linear regression was also found between NT-proBNP concentrations measured with the ADVIA and ECLIA methods (R=0.9954, n=202). However, the ADVIA method measured significantly lower BNP values than the Access method (on average -20.9%), while ADVIA PBNP method measured significantly higher NT-proBNP concentrations than the ECLIA method (on average +17.8%). Conclusions Analytical performances of the BNP and PBNP ADVIA methods are well in accordance with the quality specifications required by international guidelines for diagnosis and follow-up of patients with HF.


Assuntos
Imunoensaio/métodos , Peptídeo Natriurético Encefálico/análise , Fragmentos de Peptídeos/análise , Guias como Assunto , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/patologia , Humanos , Imunoensaio/normas , Limite de Detecção , Peptídeo Natriurético Encefálico/normas , Fragmentos de Peptídeos/normas , Kit de Reagentes para Diagnóstico , Reprodutibilidade dos Testes
11.
Clin Chim Acta ; 486: 88-93, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30040920

RESUMO

BACKGROUND: Ventricular Assist Device (VAD) as bridge to transplantation is a common therapy for adult with heart failure (HF), but VAD use is increasing also in children. Cardiac and inflammatory biomarkers have an important role in the diagnosis and prognosis of HF in adults, but their role in paediatric setting is unknown. The aim of this study was to examine changes in cardiac and inflammatory biomarkers, both in HF paediatric and adult patients, before and following VAD. METHODS: Cardiac (NT-proBNP, cTnI, sST2,Gal-3) and inflammatory (IL-6,IL-8) biomarkers were determined in plasma collected from 12 paediatric patients and 7 adult patients with HF, before and at 4 h,1,3,7,14 and 30 days after VAD implant. RESULTS: All biomarkers increased up to 1 day after VAD implant and then decreased at pre-VAD levels in 1 month in both groups. Only in children, NT-proBNP decreased significantly after 30 days Post-VAD treatment compared to pre-VAD levels. During the post-operative time-course, NT-proBNP and sST2 were significantly higher in children than adults, while IL-6 was lower. CONCLUSIONS: Cardiac and inflammatory biomarkers were differently modified by VAD implant in children compared to adults. These preliminary data could suggest that different molecular pathways may underlie HF patho-physiology of the two groups, possibly paving the way to a specific and targeted therapeutic intervention in the near future.


Assuntos
Biomarcadores/sangue , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/cirurgia , Coração Auxiliar , Inflamação/sangue , Inflamação/cirurgia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Fatores de Tempo , Adulto Jovem
12.
Clin Chem Lab Med ; 57(2): 259-267, 2018 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-30016276

RESUMO

Background The aims of this study were: (1) to calculate reliable thyroid stimulating hormone (TSH) reference intervals using laboratory databases; (2) to evaluate the relationship between TSH, sex and age values in different large Italian populations. Methods The TSH values stored in the laboratory information system of clinical laboratories of four Italian city hospitals, including 146,801 TSH measurements (with the respective age and sex data of individuals) were taken in consideration. Assuming a log-normal distribution, to log-transformed TSH values were applied the Dixon's iterative principle in order to exclude the outliers. At the end of this iterative process 142,821 log-transformed TSH results remained. The four clinical laboratories measured serum TSH concentrations using the same TSH immunoassay method (Access TSH 3rd IS, using UniCel DxI platform). Results The TSH reference interval calculated in the present study (0.362-5.280 mIU/L) is similar to that suggested by the manufacturer for the Access TSH 3rd IS assay (0.45-5.33 mIU/L). TSH values in females were significantly higher than in males (females: mean=2.06 mIU/L; standard deviation [SD]=1.26 mIU/L; n=101,243; males: mean=1.92 mIU/L; SD=1.19 mIU/L; n=41,578; p<0.0001). Moreover, a negative linear relationship was observed between TSH throughout all interval age values (from 0 to 105 years). Conclusions The results of the present multicenter study confirm that data mining techniques can be used to calculate clinically useful reference intervals for TSH. From a pathophysiological point of view, our results suggest that some Northern populations of Italy might still suffer some harmful effects on the thyroid gland due to mild to moderate iodine intake deficiency. Specific clinical trials are needed to confirm these results.


Assuntos
Tireotropina/sangue , Tireotropina/normas , Adulto , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Padrões de Referência
15.
Clin Chem Lab Med ; 56(3): 492-501, 2018 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-28941350

RESUMO

BACKGROUND: The study aim was to evaluate and compare the analytical performance of the new chemiluminescent immunoassay for cardiac troponin I (cTnI), called Access hs-TnI using DxI platform, with those of Access AccuTnI+3 method, and high-sensitivity (hs) cTnI method for ARCHITECT platform. METHODS: The limits of blank (LoB), detection (LoD) and quantitation (LoQ) at 10% and 20% CV were evaluated according to international standardized protocols. For the evaluation of analytical performance and comparison of cTnI results, both heparinized plasma samples, collected from healthy subjects and patients with cardiac diseases, and quality control samples distributed in external quality assessment programs were used. RESULTS: LoB, LoD and LoQ at 20% and 10% CV values of the Access hs-cTnI method were 0.6, 1.3, 2.1 and 5.3 ng/L, respectively. Access hs-cTnI method showed analytical performance significantly better than that of Access AccuTnI+3 method and similar results to those of hs ARCHITECT cTnI method. Moreover, the cTnI concentrations measured with Access hs-cTnI method showed close linear regressions with both Access AccuTnI+3 and ARCHITECT hs-cTnI methods, although there were systematic differences between these methods. There was no difference between cTnI values measured by Access hs-cTnI in heparinized plasma and serum samples, whereas there was a significant difference between cTnI values, respectively measured in EDTA and heparin plasma samples. CONCLUSIONS: Access hs-cTnI has analytical sensitivity parameters significantly improved compared to Access AccuTnI+3 method and is similar to those of the high-sensitivity method using ARCHITECT platform.


Assuntos
Imunoensaio/métodos , Troponina I/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Controle de Qualidade , Sensibilidade e Especificidade
16.
Eur J Appl Physiol ; 118(2): 411-417, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29256048

RESUMO

PURPOSE: Cardiac Troponins (cTnI, cTnT), NT-proBNP, and galectin-3 (GAL-3) mirror cardiomyocyte injury, stretch, and fibrosis. However, although these biomarkers has been thoroughly studied in marathon or ultramarathon, the effects occurring running shorter distances, as half-marathon, are less known and data are generally limited to immediately post-race evaluation. Moreover, significant variation of alpha-1 antitrypsin (AAT), an anti-protease factor with anti-inflammatory properties, has been recently observed in heart failure, but not investigated in paraphysiological settings. The aim of the study was to evaluate these biomarkers concentration and trends in trained runners before half-marathon run and during a 48-h recovery period. METHODS: In 18 half-marathon runners (15 males, 46 ± 6 years), cTnI, GAL-3 (Architect, Abbott), cTnT, NT-proBNP (Cobas e411, Roche), and AAT (Abcam, Cambridge, UK) were evaluated at rest, immediately post-run, and at 24 and 48-h recovery period. RESULTS: cTnT, NT-proBNP, and GAL-3 transiently increased after post-race, but normalized at 24 h (GAL-3 p < 0.01, cTnT < 0.001) or 48 h (NT-proBNP < 0.001), while cTnI and AAT did not significantly change. The frequency of values exceeding the diagnostic threshold, as evaluated at baseline and after the race, did not differ for cTnI ([Formula: see text] = 1.1, p = ns), and NT-proBNP ([Formula: see text] = 6, p = ns), but significantly increased for cTnT ([Formula: see text] = 23, p < 0.001) and GAL-3 ([Formula: see text] = 6.3, p < 0.05). None of the subjects showed AAT values exceeding the reference range at baseline and at any of the time points after the race. CONCLUSION: The transient cTnT, NT-proBNP, and GAL-3 increase may suggest a temporary stress on the myocyte. However, being the increase of all biomarkers moderate and reversible, it may represent a physiological response to acute exercise.


Assuntos
Galectina 3/sangue , Coração/fisiologia , Corrida/fisiologia , Troponina/sangue , alfa 1-Antitripsina/sangue , Adulto , Biomarcadores/sangue , Humanos , Masculino , Pessoa de Meia-Idade
17.
Clin Chem Lab Med ; 55(11): 1634-1651, 2017 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-28599373

RESUMO

According to recent international guidelines, including the 2012 Third Universal Definiton of Myocardial Infarction by the Joint ESC/ACCF/AHA/WHF Task Force, an increase in cardiac troponin (cTn) levels over the 99th percentile upper reference limit (99th URL) should be considered clinically relevant, this cut-off being measured with an imprecision ≤10 CV%. In theory 99th URL values strongly depend not only on demographic and physiological variables (i.e. criteria for considering the reference population "healthy"), but also on the analytical performance of cTn methods and mathematical algorithms used for the calculation. The aim of the present article was therefore to review the methodological and pathophysiological factors affecting the evaluation and calculation of the 99th URL for cTn assay. The critical analysis made showed that no uniform procedure is followed, and nor have experts or regulatory bodies provided uniform guidelines for researchers or cTn assays manufacturers as an aid in "their quest to define normality". In particular, little attention has been paid to the way in which a healthy reference population is to be selected, or the criteria for calculating the 99th URL value for cTn assays, thus highlighting the need for international recommendations not only for demographic and physiological variables criteria for defining a healthy reference population, but also for calculating mathematical algorithms for establishing/calculating clinical decision values. An expert consensus group, comprising laboratory and clinical scientists, biomedical statisticians, industrial and regulatory representatives, should be responsible for drawing up these guidelines.


Assuntos
Troponina I/análise , Troponina T/análise , Fatores Etários , Biomarcadores/análise , Cardiopatias/metabolismo , Cardiopatias/patologia , Humanos , Imunoensaio/normas , Valores de Referência , Fatores Sexuais , Troponina I/normas , Troponina T/normas
18.
Clin Chem Lab Med ; 55(11): 1722-1733, 2017 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-28245185

RESUMO

BACKGROUND: Systematic difference between thyroid-stimulating hormone (TSH) immunoassays may produce misleading interpretation when samples of the same patients are measured with different methods. The study aims were to evaluate whether systematic differences are present among TSH immunoassays, and whether it is possible to obtain a better harmonization among TSH methods using results obtained in external quality assessment (EQA) schemes. METHODS: Seven Italian clinical laboratories measured TSH in 745 serum samples of healthy subjects and patients with thyroid disorders. These samples were also re-measured by two reference laboratories of the study with the six TSH immunoassays most popular in Italy after 2 months of storage at -80 °C. Moreover, these data were compared to 53,823 TSH measurements, obtained by laboratories participant to 2012-2015 EQA annual cycles in 72 quality control samples (TSH concentrations from about 0.1 mIU/L to 18.0 mIU/L). TSH concentrations were recalibrated using a mathematical approach based on the principal component analysis (PCA). RESULTS: Systematic differences were found between the most popular commercially available TSH immunoassays. TSH concentrations measured by the clinical laboratories were very closely correlated to those measured with the same method by reference laboratories after 2 months of storage at -80 °C. After recalibration using the PCA approach the variation of TSH values significantly decreased from a median pre-calibration value of 13.53% (10.79%-16.53%) to 9.63% (6.90%-13.21%) after recalibration. CONCLUSIONS: Our data suggest that EQA schemes are useful to improve harmonization among TSH immunoassays and also to produce some mathematical formulas, which can be used by clinicians to better compare TSH values measured with different methods.


Assuntos
Imunoensaio/métodos , Tireotropina/sangue , Calibragem , Humanos , Imunoensaio/normas , Laboratórios/normas , Modelos Lineares , Análise de Componente Principal , Controle de Qualidade , Kit de Reagentes para Diagnóstico , Doenças da Glândula Tireoide/diagnóstico , Tireotropina/normas
19.
Clin Chim Acta ; 468: 105-110, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28189596

RESUMO

AIM OF THE STUDY: Recently, Beckman Coulter Diagnostics set up a new TSH immunoassay for the automated DxI platform. The aim of this study was to evaluate and compare the analytical performance and clinical results of this method with those of previous method. MATERIAL AND METHODS: A multicenter study (named TSH ELAS Study) was organized using 593 serum samples, collected from healthy subjects and patients with thyroid disorders, and 13 control samples, circulated in an External Quality Assessment (EQA) scheme. RESULTS: The values of LoB and LoD, and LoQ at 20% CV were 0.0004mIU/L, 0.001mIU/L and 0.0023mIU/L, respectively. Moreover, TSH concentrations >0.01mIU/L actually show imprecision values lower than 5% CV. This new TSH assay showed a systematic underestimation (on average of 6.25%) compared to old method, which is mainly due to larger differences between methods for samples with low TSH concentrations, related to the better analytical sensitivity of new compared to old method. In a reference population, including 279 apparently healthy adult subjects, Caucasian volunteers (mean age 43.6years, age 20-63years, 138 women and 141 males) the distribution of TSH concentrations was: mean (CI 95%) 1.694mIU/L (1.588-1.779), median 1.495mIU/L (1.412-1.588mIU/L), 97.5th percentile 3.707mIU/L. CONCLUSIONS: The new TSH immunoassay for DxI platform shows some relevant improvements compared to the previous one: use of the most recent WHO 3rd IRP 81/563 standard and monoclonal antibodies (instead of polyclonal antibodies of the old method), and better analytical sensitivities and reproducibility.


Assuntos
Imunoensaio/métodos , Tireotropina/sangue , Adulto , Automação , Estudos de Casos e Controles , Feminino , Humanos , Imunoensaio/normas , Masculino , Pessoa de Meia-Idade , Controle de Qualidade , Valores de Referência , Reprodutibilidade dos Testes , Neoplasias da Glândula Tireoide/sangue , Adulto Jovem
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