Estrategias para la reconversión del ejercicio profesional: Proyecto Bioquímico Nexo / Strategies for the reconversion of professional practice: Biochemical Nexus Project

El avance de la ciencia y la tecnología en el área de la bioquímica clínica ha ocasionado la necesidad de reflexionar acerca de una reingeniería de la práctica profesional. El proceso diagnóstico es complejo y dinámico, requiere del trabajo interdisciplinario y de la comunicación efectiva, además de un cambio en el accionar profesional, con el eje centrado en el paciente y en un laboratorio "a puertas abiertas". En este marco se planteó el Proyecto Bioquímico Nexo (BN) con el propósito de lograr las competencias y habilidades necesarias para formar profesionales bioquímicos clínicos integrales que puedan cumplir con este nuevo rol sobre la base de una construcción colectiva de los saberes (AU)

Advances in science and technology in the area of clinical biochemistry have prompted the need to reflect on the reengineering of professional practice. The diagnostic process is complex and dynamic, requiring interdisciplinary work and effective communication, as well as a change in professional action, with the focus on the patient and an "open-door" laboratory. Within this framework, the Biochemical Nexus Project (BN) was proposed with the purpose of achieving the competencies and skills necessary to comprehensively train clinical biochemists who can fulfill this new role based on a collective construction of knowledge (AU)

The new, race-free, Chronic Kidney Disease Epidemiology Consortium (CKD-EPI) equation to estimate glomerular filtration rate: is it applicable in Europe? A position statement by the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM).

The EFLM recommends not to implement the race-free Chronic Kidney Disease Epidemiology Consortium (CKD-EPI) equation in European laboratories and to keep the 2009 version of the CKD-EPI equation, without applying a race correction factor. This recommendation is completely in line with a recent Editorial published by the European Renal Association who has also proposed to change to a novel equation only when it has considerably better performance, trying to reach global consensus before implementing such a new glomerular filtration rate (GFR) estimation equation. In Europe, this equation could be for instance the new European Kidney Function Consortium (EKFC) equation, which is population-specific, developed from European cohorts and accurate from infants to the older old. Beyond serum creatinine, the estimating equations based on cystatin C will probably gain in popularity, especially because cystatin C seems independent of race. Finally, we must keep in mind that all GFR equations remain an estimation of GFR, especially rough at the individual level. Measuring GFR with a reference method, such as iohexol clearance, remains indicated in specific patients and/or specific situations, and here also, the role of the clinical laboratories is central and should still evolve positively in the future.

Practical application of European biological variation combined with Westgard Sigma Rules in internal quality control.

OBJECTIVES: Westgard Sigma Rules is a statistical tool available for quality control. Biological variation (BV) can be used to set analytical performance specifications (APS). The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) regularly updates BV data. However, few studies have used robust BV data to determine quality goals and design a quality control strategy for tumor markers. The aim of this study was to derive APS for tumor markers from EFLM BV data and apply Westgard Sigma Rules to establish internal quality control (IQC) rules. METHODS: Precision was calculated from IQC data, and bias was obtained from the relative deviation of the External quality assurance scheme (EQAS) group mean values and laboratory-measured values. Total allowable error (TEa) was derived using EFLM BV data. After calculating sigma metrics, the IQC strategy for each tumor marker was determined according to Westgard Sigma Rules. RESULTS: Sigma metrics achieved for each analyte varied with the level of TEa. Most of these tumor markers except neuron-specific enolase reached 3σ or better based on TEamin. With TEades and TEaopt set as the quality goals, almost all analytes had sigma values below 3. Set TEamin as quality goal, each analyte matched IQC muti rules and numbers of control measurements according to sigma values. CONCLUSIONS: Quality goals from the EFLM BV database and Westgard Sigma Rules can be used to develop IQC strategy for tumor markers.

Verification of examination procedures for 72 biochemical parameters on the atellica® clinical chemistry and immunoassay analyzers.

The verification of examination procedures is a responsibility for clinical laboratories in order to guarantee that their performance characteristics comply with the specifications obtained during the validation process and are congruent with the intended scope of the assay. The aim was to perform an evaluation of precision, bias, linearity, linear drift, sample carry-over, and comparability of 73 assays from Siemens Healthineers, by following the CLSI EP10-A3 guidelines. The verification was performed by measuring 72 biochemical parameters in quality control (QC) materials from Bio-Rad (except for IL6) with 73 assays installed on eight measuring systems (five Atellica® CH 930 and three IM 1600 analyzers from Siemens Healthcare Diagnostics). The following information was collected: validation data from manufacturer, biological variation data from the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) database, and specifications for fßhCG and PAPP-A assays to meet the Fetal Medicine Foundation standards. A total of 17550 results were obtained during EP10 verification process. Out of the 73 methods, only Cl-S, Mg-S, and Na-S failed the criteria for adequate precision, trueness, and comparability. The assays did not show significant loss of linearity, linear drift, or sample carry-over. This study allowed the initial training and familiarization with the instruments and the identification of operational issues. It also represented an opportunity to evaluate the QCs and to obtain analytical performance information for application of sigma six metrics for quality assurance. Professionals are advised to adequately standardize and protocolize their verification processes to ensure laboratory competence and patient safety.

[Pseudohyperkalemia: clinical chemistry for the clinician]. / Pseudohyperkaliëmie: klinische chemie voor clinici.

BACKGROUND: Hyperkalemia is an electrolyte disorder requiring medical attention because it can cause cardiac arrhythmias. Pseudohyperkalemia is the phenomenon of an elevated potassium concentration that is present in the blood sample but not in the patient. Pseudohyperkalemia can be caused by hemolysis, leukocytosis, thrombocytosis, seasonal pseudohyperkalemia, potassium release from muscle cells due to fist clenching during venipuncture, and contamination due to blood withdrawal from an intravenous line over which potassium was administered. Rarer causes include EDTA contamination and familial pseudohyperkalemia. CASE DESCRIPTION: A 23-year old woman was admitted with ascites due to polycythemia vera and essential thrombocytosis for which hydroxycarbamide was started. The reported serum potassium concentrations were 6.1 and 6.8 mmol/l. The use of spironolactone was discontinued and she was treated with sodium polystyrene sulfonate and insulin-glucose infusion. The serum potassium concentration only decreased on the ninth day of admission, when the thrombocyte count was normalizing. A diagnosis of pseudohyperkalemia due to thrombocytosis was established. CONCLUSION: Knowledge of the causes of pseudohyperkalemia and interaction between the clinician and clinical chemist aids in the differentiation between true hyperkalemia and pseudohyperkalemia and may prevent unnecessary diagnostics and harmful treatment.

Reference Intervals for Clinical Chemistry Analytes for Transgender Men and Women on Stable Hormone Therapy.

BACKGROUND: Gender-affirming hormone therapy with either estradiol or testosterone is commonly prescribed for transgender individuals. Masculinizing or feminizing hormone therapy may impact clinical chemistry analytes, but there is currently a lack of published reference intervals for the transgender population. METHODS: Healthy transgender and nonbinary individuals who had been prescribed either estradiol (n = 93) or testosterone (n = 82) for at least 12 months were recruited from primary care and internal medicine clinics specializing in transgender medical care. Electrolytes, creatinine, urea nitrogen, enzymes (alkaline phosphatase, ALK; alanine aminotransferase, ALT; aspartate aminotransferase, AST; gamma-glutamyltransferase, GGT), hemoglobin A1c, lipids [total cholesterol, high-density lipoprotein (HDL), triglycerides], and high-sensitivity C-reactive protein (hsCRP) were measured on 2 clinical chemistry platforms. Reference intervals (central 95%) were calculated according to Clinical Laboratory Standards Institute guidelines. RESULTS: There was minimal impact of gender-affirming hormone therapy on electrolytes, urea nitrogen, hemoglobin A1c, and hsCRP. In general, the enzymes studied shifted toward affirmed gender. Creatinine values for both transgender cohorts overlaid the reference interval for cisgender men, with no shift toward affirmed gender for the estradiol cohort. The effects on lipids were complex, but with a clear shift to lower HDL values in the testosterone cohort relative to cisgender women. CONCLUSIONS: Transgender individuals receiving either masculinizing or feminizing hormone therapy showed significant changes in some analytes that have sex-specific variation in the cisgender population. The clearest shifts toward affirmed gender were seen with enzymes for the estradiol and testosterone cohorts and with creatinine and HDL in the testosterone cohort.

Could S-Monovette Serum Gel Tubes be Used for Clinical Chemistry Analysis Instead of Serum Separator Tube II Advance?

BACKGROUND: We aimed to compare the Sarstedt S-Monovette serum gel tube and the BD (Becton, Dickinson and Company) Serum Separator Tube II (SST II) Advance based on technical specifications and tests results. METHODS: One hundred and twenty volunteers were included in the technical evaluation and 42 of 120 volunteers in the clinical evaluation. Blood was collected into S-Monovette, and SST II. Twelve quality indicators (QI) were determined for technical evaluation. For clinical evaluation, 29 clinical chemistry analytes were analysed simultaneously on a Roche Cobas 6000 c501 (Roche Diagnostics, Mannheim, Germany). Calculations were made using the formula suggested by the EFLM according to the QIs. If the difference between S-Monovette and SST II was < 1%, S-Monovette was considered sufficient for relevant QI. For clinical evaluation, Passing Bablok regression analysis and Bland-Altman plots were used. Desirable bias values for comparison with mean percentage difference (MPD) were obtained from biological variation databases. RESULTS: S-Monovette tubes were found to be suitable for all QIs (difference < 1%). No significant differences were observed in analytes except lactate dehydrogenase (LDH). LDH results (U/L) obtained from the SST II were statistically significantly higher (SST II: 201 ± 42, S-Monovette: 195 ± 35, regression equation was y = 31.4 + 0.8x). The MPD of LDH (2.4%) remained within the desirable bias (3.4%); however, the 95% CI of the MPD of LDH (0.5% - 4.4%) exceeded the desirable bias. CONCLUSIONS: S-Monovette has been deemed appropriate for use in clinical chemistry analysis, as the MPD of LDH and other analytes remained within the bias limits. The LDH was considered sensitive to microhemolysis as a possible reason for the difference in LDH results.

Insights and prospects for ion mobility-mass spectrometry in clinical chemistry.

INTRODUCTION: Ion mobility-mass spectrometry is an emerging technology in the clinical setting for high throughput and high confidence molecular characterization from complex biological samples. Ion mobility spectrometry can provide isomer separations on the basis of molecular structure, the ability of which is increasing through technological developments that afford enhanced resolving power. Integrating multiple separation dimensions, such as liquid chromatography-ion mobility-mass spectrometry (LC-IM-MS) provide dramatic enhancements in the mitigation of molecular interferences for high accuracy clinical measurements. AREAS COVERED: Multidimensional separations with LC-IM-MS provide better selectivity and sensitivity in molecular analysis. Mass spectrometry imaging of tissues to inform spatial molecular distribution is improved by complementary ion mobility analyses. Biomarker identification in surgical environments is enhanced by intraoperative biochemical analysis with mass spectrometry and holds promise for integration with ion mobility spectrometry. New prospects in high resolving power ion mobility are enhancing analysis capabilities, such as distinguishing isomeric compounds. EXPERT OPINION: Ion mobility-mass spectrometry holds many prospects for the field of isomer identification, molecular imaging, and intraoperative tumor margin delineation in clinical settings. These advantages are afforded while maintaining fast analysis times and subsequently high throughput. High resolving power ion mobility will enhance these advantages further, in particular for analyses requiring high confidence isobaric selectivity and detection.

The European Biological Variation Study (EuBIVAS): a summary report.

Biological variation (BV) data have many important applications in laboratory medicine. Concerns about quality of published BV data led the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) 1st Strategic Conference to indicate need for new studies to generate BV estimates of required quality. In response, the EFLM Working Group on BV delivered the multicenter European Biological Variation Study (EuBIVAS). This review summarises the EuBIVAS and its outcomes. Serum/plasma samples were taken from 91 ostensibly healthy individuals for 10 consecutive weeks at 6 European centres. Analysis was performed by Siemens ADVIA 2400 (clinical chemistry), Cobas Roche 8000, c702 and e801 (proteins and tumor markers/hormones respectively), ACL Top 750 (coagulation parameters), and IDS iSYS or DiaSorin Liaison (bone biomarkers). A strict preanalytical and analytical protocol was applied. To determine BV estimates with 95% CI, CV-ANOVA after analysis of outliers, homogeneity and trend analysis or a Bayesian model was applied. EuBIVAS has so far delivered BV estimates for 80 different measurands. Estimates for 10 measurands (non-HDL cholesterol, S100-ß protein, neuron-specific enolase, soluble transferrin receptor, intact fibroblast growth-factor-23, uncarboxylated-unphosphorylated matrix-Gla protein, human epididymis protein-4, free, conjugated and %free prostate-specific antigen), prior to EuBIVAS, have not been available. BV data for creatinine and troponin I were obtained using two analytical methods in each case. The EuBIVAS has delivered high-quality BV data for a wide range of measurands. The BV estimates are for many measurands lower than those previously reported, having an impact on the derived analytical performance specifications and reference change values.

[Clinical chemistry laboratory assay of circulating oncology biomarkers : limitations and perspectives]. / Dosage au laboratoire de chimie clinique des biomarqueurs circulants oncologiques : limites et perspectives.

In current practice, the use of circulating oncological biomarkers by clinicians is almost inseparable from cancer patients management. However, the interpretation of the results is not always easy because it is more specific to laboratory medicine and involves notions of peri-analytical orders as well as analytical sensitivity and specificity. In the past, the development of new analytical techniques improved the analytical sensitivity or allowed the implementation of new biomarkers; this observation would still be true today. Mass spectrometry, microRNA assay, or Single Molecule Array (SiMoA) are recent analytical developments with very good analytical performances that could contribute to the improvement of cancer patient management.

Dans la pratique courante, le recours des cliniciens aux biomarqueurs circulants oncologiques est presque indissociable de la prise en charge des patients cancéreux. Cependant, l'interprétation des résultats n'est pas toujours aisée. Elle est, en effet, plus spécifique à la médecine de laboratoire faisant intervenir des notions d'ordres péri-analytiques ainsi que celles de sensibilité et spécificité analytiques. Comme il a été démontré par le passé, le développement de nouvelles techniques d'analyses a permis d'abaisser le seuil de sensibilité analytique, ou encore, l'implémentation de nouveaux biomarqueurs; cette observation se vérifierait encore aujourd'hui. La spectrométrie de masse, le dosage des microARN, ou encore le Single Molecule Array (SiMoA) sont des méthodes d'analyse récentes présentant de très bonnes performances analytiques qui pourraient contribuer à l'amélioration de la prise en charge des patients cancéreux.

Activity-based cost analysis of laboratory tests in clinical chemistry.

OJECTIVES: Since health care budgets are limited and must be allocated efficiently, there is an economic pressure to reduce the costs of health care interventions. This study aims to investigate the cost of testing within a Clinical Chemistry laboratory. METHODS: This study was conducted in the Clinical Chemistry laboratory of the University Hospital UZ Brussel, Belgium, in which 156 tests were included and an average cost per test was calculated for the year 2018. Activity-based costing (ABC) was applied, using a top-down perspective. Costs were first allocated to different activity centers and subsequently to different tests. Number of tests, parameters, analyzers and time estimates were used as activity cost drivers. RESULTS: The blood glucose test on the point-of-care testing (POCT) analyzer Accu Chek Inform II had the lowest unit cost (€0.92). The determination of methanol, ethanol and isopropanol on the GC-FID (7820A) is the test with the highest unit cost (€129.42). In terms of average cost per test per activity center, core laboratory (€3.37) scored lowest, followed consecutively by POCT (€3.49), diabetes (€22.09), toxicology (€31.52), metabolic disorder (€41.53) and cystic fibrosis (€86.02). The cost per test was mainly determined by staff (57%), costs of support services (23%) and reagents (14%). CONCLUSIONS: High-volume and automated tests have lower unit costs, as is the case with the core laboratory. ABC provides the ability to identify high average cost tests that can benefit from optimizations, such as focusing on automation or outsourcing low-volume tests that can benefit from economies of scale.

The Time Has Come for Quantitative Protein Mass Spectrometry Tests That Target Unmet Clinical Needs.

Protein mass spectrometry (MS) is an enabling technology that is ideally suited for precision diagnostics. In contrast to immunoassays with indirect readouts, MS quantifications are multiplexed and include identification of proteoforms in a direct manner. Although widely used for routine measurements of drugs and metabolites, the number of clinical MS-based protein applications is limited. In this paper, we share our experience and aim to take away the concerns that have kept laboratory medicine from implementing quantitative protein MS. To ensure added value of new medical tests and guarantee accurate test results, five key elements of test evaluation have been established by a working group within the European Federation for Clinical Chemistry and Laboratory Medicine. Moreover, it is emphasized to identify clinical gaps in the contemporary clinical pathways before test development is started. We demonstrate that quantitative protein MS tests that provide an additional layer of clinical information have robust performance and meet long-term desirable analytical performance specifications as exemplified by our own experience. Yet, the adoption of quantitative protein MS tests into medical laboratories is seriously hampered due to its complexity, lack of robotization and high initial investment costs. Successful and widespread implementation in medical laboratories requires uptake and automation of this next generation protein technology by the In-Vitro Diagnostics industry. Also, training curricula of lab workers and lab specialists should include education on enabling technologies for transitioning to precision medicine by quantitative protein MS tests.

Stabilization of urinary biogenic amines measured in clinical chemistry laboratories.

Urinary 5-hydroxyindoleacetic acid (5-HIAA), vanillylmandelic (VMA), homovanillic acid (HVA), catecholamines and metanephrines are produced in excess by catecholamine-producing tumors. These biogenic amines are unstable at low or high pH and require hydrochloric acid (HCl) to prevent their degradation. However, HCl addition may result in very low pH causing degradation or deconjugation of several metabolites. This study evaluated the buffering properties of sodium citrate to stabilize all biogenic amines. The metabolite concentrations were measured by LC-MS/MS or by a coulometric assay in 22 urine samples collected native and with HCl or sodium citrate. We studied the effect of pH, time (48 h, four weeks) and storage temperature at 22 °C, 4 °C, and -20 °C. We found that catecholamines degradation was prevented by HCl and citrate and that 5-HIAA was degraded in 5 out of 22 samples collected with HCl. All biogenic amines were efficiently stabilized by citrate for four weeks at 22 °C, except epinephrine (48 h at 4 °C, or four weeks at -20 °C). Sodium citrate did not cause quantification or analytical artefacts concerns. In conclusion, sodium citrate is a non-hazardous alternative to HCl for patients to send unfrozen urine samples to the laboratory which may safely store the sample for four weeks.

Laboratory abnormalities in children with mild and severe coronavirus disease 2019 (COVID-19): A pooled analysis and review.

Limited data exists to-date on the laboratory findings in children with COVID-19, warranting the conduction of this study, in which we pool the currently available literature data on the laboratory findings seen in children with mild and severe COVID-19. Following an extensive literature search, we identified 24 eligible studies, including a total of 624 pediatric cases with laboratory-confirmed COVID-19, which report data on 27 different biomarkers. We then performed a meta-analysis to calculate the pooled prevalence estimates (PPE) for these laboratory abnormalities in mild COVID-19. As data was too limited for children with severe COVID-19 to allow pooling, results were presented descriptively in a summary of findings table. Our data show an inconsistent pattern of change in the leukocyte index of mild and severe cases of COVID-19 in children. Specifically, changes in leukocyte counts were only observed in 32% of the mild pediatric cases (PPE: 13% increase, 19% decrease). In mild disease, creatine kinase-MB (CK-MB) was frequently elevated, with a PPE of 33%. In severe disease, c-reactive protein (CRP), procalcitonin (PCT), and lactate dehydrogenase (LDH) were frequently elevated. Based on data obtained from early COVID-19 studies, leukocyte indices in children appear inconsistent, differing from those reported in adults that highlight specific leukocyte trends. This brings into question the utility and reliability of such parameters in monitoring disease severity in the pediatric population. Instead, we suggest physicians to serially monitor CRP, PCT, and LDH to track the course of illness in hospitalized children. Finally, elevated CK-MB in mild pediatric COVID-19 cases is indicative of possible cardiac injury. This highlights the importance of monitoring cardiac biomarkers in hospitalized patients and the need for further investigation of markers such as cardiac troponin in future studies.

European Biological Variation Study (EuBIVAS): within- and between-subject biological variation estimates of ß-isomerized C-terminal telopeptide of type I collagen (ß-CTX), N-terminal propeptide of type I collagen (PINP), osteocalcin, intact fibroblast growth factor 23 and uncarboxylated-unphosphorylated matrix-Gla protein-a cooperation between the EFLM Working Group on Biological Variation and the International Osteoporosis Foundation-International Federation of Clinical Chemistry Committee on Bone Metabolism.

We have calculated the biological variation (BV) of different bone metabolism biomarkers on a large, well-described cohort of subjects. BV is important to calculate reference change value (or least significant change) which allows evaluating if the difference observed between two consecutive measurements in a patient is biologically significant or not. INTRODUCTION: Within-subject (CVI) and between-subject (CVG) biological variation (BV) estimates are essential in determining both analytical performance specifications (APS) and reference change values (RCV). Previously published estimates of BV for bone metabolism biomarkers are generally not compliant with the most up-to-date quality criteria for BV studies. We calculated the BV and RCV for different bone metabolism markers, namely ß-isomerized C-terminal telopeptide of type I collagen (ß-CTX), N-terminal propeptide of type I collagen (PINP), osteocalcin (OC), intact fibroblast growth factor 23 (iFGF-23), and uncarboxylated-unphosphorylated Matrix-Gla Protein (uCuP-MGP) using samples from the European Biological Variation Study (EuBIVAS). METHODS: In the EuBIVAS, 91 subjects were recruited from six European laboratories. Fasting blood samples were obtained weekly for ten consecutive weeks. The samples were run in duplicate on IDS iSYS or DiaSorin Liaison instruments. The results were subjected to outlier and variance homogeneity analysis before CV-ANOVA was used to obtain the BV estimates. RESULTS: We found no effect of gender upon the CVI estimates. The following CVI estimates with 95% confidence intervals (95% CI) were obtained: ß-CTX 15.1% (14.4-16.0%), PINP 8.8% (8.4-9.3%), OC 8.9% (8.5-9.4%), iFGF23 13.9% (13.2-14.7%), and uCuP-MGP 6.9% (6.1-7.3%). CONCLUSIONS: The EuBIVAS has provided updated BV estimates for bone markers, including iFGF23, which have not been previously published, facilitating the improved follow-up of patients being treated for metabolic bone disease.

British Journal of Biomedical Science in 2019. What have we learned?

In 2019 the British Journal of Biomedical Science published 40 articles in the various disciplines that comprise biomedical science. These were one review, 22 original articles and 17 'In Brief' short reports. Of those citing original data, the majority were in cellular pathology (14 papers), clinical chemistry (9 papers), and microbiology (6 papers: 4 in bacteriology and 2 in virology). There were 3 papers in haematology and 2 in andrology, whilst 5 papers crossed traditional discipline boundaries (such as the molecular genetics of IL6, liver function tests, and hepatocellular carcinoma). Over two-thirds of papers used techniques in molecular genetics. The present report will summarise key aspects of these publications that are of greatest relevance to laboratory scientists.

Tomar mate previo a la flebotomía no interfiere en las pruebas bioquímicas de rutina / Drinking mate prior to phlebotomy does not interfere with routine biochemical tests

En este estudio se evaluó el efecto de tomar mate en las pruebas bioquímicas de rutina. Se extrajo sangre a 32 mujeres voluntarias luego de 12 horas de ayuno y a la hora (T1), dos horas (T2) y tres horas (T3) posteriores a la toma de 5 mates. Se estudiaron parámetros hematológicos y analitos de química clínica. Los resultados se analizaron empleando pruebas estadísticas para muestras relacionadas. Se calculó la diferencia porcentual media (DM%) de cada analito en cada hora respecto del valor basal y se comparó con el valor de referencia del cambio (VRC). Una DM% mayor que el VRC se consideró clínicamente significativa. En T1, T2 y T3 los recuentos de neutrófilos, eosinófilos y linfocitos fueron más bajos que en T0, también los niveles de glucosa, urea, creatinina y cistatina C fueron más bajos que en T0, mientras que los valores de proteínas totales, colesterol transportado por lipoproteínas de baja densidad y la actividad enzimática de lactato deshidrogenasa fueron más altos que en T0. En todos los casos los cambios fueron estadísticamente significativos, aunque no lo fueron desde el punto de vista clínico. Tomar 5 mates antes de la flebotomía no interfiere en los resultados de las pruebas bioquímicas de rutina.

In the present study the effect of drinking mate in routine biochemical tests was evaluated. Blood was collected from 32 female volunteers after a 12 h fasting period. In addition, 1 hour (T1), 2 hours (T2), and 3 hours (T3) after drinking 5 mates, blood was collected again. Hematological parameters and clinical chemistry analytes were studied. The results were analyzed using statistical tests for related samples. Mean difference % (MD%) was calculated for each analyte and was further compared with reference change value (RCV). The MDs% higher than RCV were considered clinically significant. At T1, T2, and T3 the count neutrophils, eosinophils and lymphocytes were lower than at T0. Also glucose, urea, creatinine, and cystatin C values were lower than at T0 whereas total proteins, LDL-C, and LD enzymatic activity values were higher than at T0. In all cases, variability was statistically significant but not clinically significant. Drinking 5 mates prior to phlebotomy does not interfere with the results of routine biochemical tests.

Neste trabalho, o efeito de beber chimarrão foi avaliado em testes bioquímicos de rotina. O sangue foi extraído de 32 mulheres voluntárias após 12 horas de jejum, e uma hora (T1), duas horas (T2) e três horas (T3) após a tomada de 5 chimarrões. Parâmetros hematológicos e analitos de química clínica foram estudados. Os resultados foram analisados utilizando testes estatísticos para amostras relacionadas. A diferença percentual média% (DM%) de cada analito em cada hora foi calculada em relação ao valor basal e comparada com o valor de referência da modificação (VRM). Uma DM% maior que o VRM foi considerada clinicamente significativa. Em T1, T2 e T3 as contagens de neutrófilos, eosinófilos e linfócitos foram mais baixas que em T0, Também os níveis de glicose, ureia, creatinina e cistatina C foram mais baixos que em T0, ao passo que os valores de proteínas totais, colesterol transportado por lipoproteínas de baixa densidade e a atividade enzimática de lactato desidrogenase foram mais altos que em T0. Em todos os casos as alterações foram estatisticamente significativas, embora do ponto de vista clínico não o tenham sido. Tomar 5 chimarrões antes da flebotomia não interfere nos resultados dos testes bioquímicos de rotina.

EQA-based evaluation of metrological traceability of clinical chemistry test results in Argentina / EQA-based evaluation of metrological traceability of clinical chemistry test results in Argentina

Equivalence of results among laboratories is a major mission for medical laboratories. In the Netherlands, medical laboratories only use homogenous, commercial for general chemistry analytes, whereas in Argentina heterogenous, home brew test applications are common. The effect of this practice difference on test accuracy is studied using key features of the accuracy-based EQA program of the Netherlands. Six frozen, human-based, commutable poolsera, covering the (patho) physiological measuring range for 17 general chemistry analytes, were assayed by ~75 Argentinian labs and ~200 Dutch laboratories in 2014. After removal of outliers, harmonization status among laboratories was evaluated by calculating overall mean interlaboratory coefficients of variation (CVs, %) per analyte and per country for all 6 levels. Evenso, standardization status was evaluated after removal of outliers by calculating overall mean recoveries (%) as compared to the assigned target values per analyte per country for all 6 levels. Absolute median biases were compared to (minimal/desirable) biases derived from biological variation criteria. For serum enzymes interlaboratory CVs in the Argentinian laboratories ranged between 10 and 22%, as compared to 3-6% in the Netherlands. For serum uric acid, creatinine, glucose and total protein, interlaboratory CVs varied between 4.3 and 13.1% in Argentinian labs, as compared to <3.5% in the Netherlands. For serum electrolytes, interlaboratory CVs ranged between 1.8 and 3.8% for Na+; 2.9-5.8% for Cl-; 3.8-7.5% for K+; 9.4-10.4% for Ca2+ and 16.2-22.3% for Mg2+ as compared to ≤2% (Na+, K+, Cl-, Ca2+) and ≤3% (Mg2+) in the Netherlands. Mean recoveries in Argentinian laboratories for e.g. serum creatinine, glucose, CK, Ca2+ and Na+ were 95-119%; 95-104%; 98-102%; 98-102% and 96-100% respectively, whereas min-max recovery ranges were 65-155%; 58-126%; 47-132%; 66-132% and 85-115%. In the Netherlands, absolute mean recoveries were overall 98.9% with a SD of 2.0%. Median biases in Argentinian laboratories ranged from -2.9 to 18.2%; -3.1 - 2.6%; -3.3 - 0.5%; -1.1 - 3.8% and -4.3-0% for serum creatinine, glucose, CK, Ca2+ and Na+. In the Netherlands overall mean/median biases were 1.1% (SD=2.0%). Exchange of commutable, value- assigned EQA-materials was helpful for studying the harmonization and standardization status of medical tests in Argentina, and for revealing the future harmonization and standardization potential. The results clearly demonstrate that metrological traceability of test results in Argentina is on average in line with what is expected; yet, the spreading among laboratories is far too high and should be improved.

La equivalencia de resultados entre laboratorios es una mision importante para los laboratorios medicos. En los Paises Bajos, los laboratorios medicos solo usan aplicaciones comerciales homogeneas, regulatoriamente aprobadas (CE-IVD) para analitos quimicos, mientras que en la Argentina son comunes las aplicaciones heterogeneas caseras. El efecto de esta diferencia practica en la precision de la prueba se estudia utilizando caracteristicas clave del programa EQA, basado en la precision, de los Paises Bajos. Se ensayaron seis pools de sueros, congelados, de origen humano, conmutables, que cubrian el rango de medidas (pato)fisiologicas para 17 analitos de quimica clinica. Estos analitos de quimica clinica fueron analizados por ~75 laboratorios argentinos y ~200 laboratorios holandeses en 2014. Despues de eliminar los valores atipicos, el estado de armonizacion entre los laboratorios fue evaluado calculando los coeficientes de variacion interlaboratorios medios globales (CV%) por analito y por pais para los 6 niveles. No obstante, el estado de estandarizacion se evaluo despues de la eliminacion de valores atipicos mediante el calculo de recuperaciones medias generales (%) en comparacion con los valores asignados por analito por pais para los 6 niveles. Los sesgos medios absolutos se compararon con los sesgos (minimos / deseables) derivados de los criterios de variacion biologica. Para enzimas sericas los CV interlaboratorio en los laboratorios argentinos oscilaron entre 10 y 22%, en comparacion con 3-6% en los Paises Bajos. Para el acido urico serico, creatinina, glucosa y proteinas totales, los CV entre laboratorios variaron entre 4,3 y 13,1% en los laboratorios argentinos, en comparacion con <3,5% en los Paises Bajos. Para los electrolitos sericos, los CV interlaboratorios oscilaron entre 1,8 y 3,8% para Na+; 2,9-5,8% para Cl-; 3,8-7,5% para K+; 9,4-10,4% para Ca2+ y 16,2-22,3% para Mg2+ en comparacion a ≤2% (Na+, K+, Cl-, Ca2+) y ≤3% (Mg2+) en los Paises Bajos. Las recuperaciones medias en laboratorios argentinos para, p.ej. la creatinina serica, glucosa, CK, Ca2+ y Na+ fueron 95-119%; 95-104%; 98-102%; 98-102% y 96-100% respectivamente, mientras que los rangos de recuperacion min-max fueron 65-155%; 58-126%; 47-132%; 66-132% y 85-115%. En los Paises Bajos, las recuperaciones medias absolutas fueron en general del 98,9% con una desviacion estandar (DE) del 2,0%. La mediana de los sesgos medios de los laboratorios argentinos oscilo entre -2,9 y 18,2%; -3,1 - 2,6%; -3,3 - 0,5%; -1,1 - 3,8% y -4,3-0% para creatinina serica, glucosa, CK, Ca2+ y Na+. En los Paises Bajos, las medias / medianas en general fueron de 1,1% (DE=2,0%). El intercambio de los valores asignados a los materiales EQA, conmutables fue de gran ayuda para la armonizacion y estandarizacion de los ensayos medicos en la Argentina y para revelar el potencial futuro de armonizacion y estandarizacion. Estos resultados claramente demuestran que la trazabilidad metrologica de los resultados de las pruebas en la Argentina esta, en promedio, de acuerdo con lo esperable; sin embargo, la dispersion entre laboratorios es muy grande y deberia ser mejorada.

A equivalencia de resultados entre laboratorios e uma missao importante para os laboratorios medicos. Nos Paises Baixos, os laboratorios medicos so utilizam aplicacoes comerciais homogeneas, aprovadas por regulacoes (CE-IVD) para analitos quimicos, ao passo que na Argentina sao comuns as aplicacoes heterogeneas caseiras. O efeito desta diferenca pratica na exatidao do teste e estudado utilizando caracteristicas essenciais do programa EQA, dos Paises Baixos, baseado na exatidao. Foram ensaiados seis pools de soros, congelados, de origem humana, comutaveis, que abrangiam a faixa de medidas (pato)fisiologicas para 17 analitos quimicos gerais. Esses analitos quimicos foram analisados por ~75 laboratorios argentinos e ~200 laboratorios holandeses em 2014. Apos eliminar os valores atipicos, o estado de harmonizacao entre os laboratorios foi avaliado atraves do calculo dos coeficientes de variacao interlaboratorio meios globais (CV%) por analito e por pais para os 6 niveis. Nao obstante, o estado de padronizacao foi avaliado depois da eliminacao de valores atipicos pelo calculo de recuperacoes medias gerais (%) se comparados com os valores atribuidos por analito por pais para os 6 niveis. Os vieses medios absolutos foram comparados com os vieses (minimos / desejaveis) decorrentes dos criterios de variacao biologica. Para enzimas sericas, os CV interlaboratorio nos laboratorios argentinos oscilaram entre 10 e 22%, em comparacao com 3-6% nos Paises Baixos. Para o acido urico serico, creatinina, glicose e proteinas totais, os CV entre laboratorios variaram entre 4,3 e 13,1% nos laboratorios argentinos, em comparacao com <3,5% nos Paises Baixos para os eletrolitos sericos, os CV interlaboratorios oscilaram entre 1,8 e 3,8% para Na+; 2,9-5,8% para Cl-; 3,8-7,5% para K+; 9,4-10,4% para Ca2+ e 16,2-22,3% para Mg2+ em comparacao com ≤2% (Na+, K+, Cl-, Ca2+) e ≤3% (Mg2+) nos Paises Baixos. As recuperacoes medias em laboratorios argentinos para, p.ex. a creatinina serica, glicose, CK, Ca2+ e Na+ foram 95-119%; 95-104%; 98-102%; 98-102% e 96-100% respectivamente, enquanto que os intervalos de recuperacao min-max. foram 65-155%; 58-126%; 47-132%; 66-132% e 85-115%. Nos Paises Baixos, as recuperacoes medias absolutas foram em geral de 98,9% com um desvio padrao (DE) de 2,0%. A mediana dos vieses medios dos laboratorios argentinos oscilou entre -2,9 e 18,2%; -3,1 - 2,6%; -3,3 - 0,5%; -1,1 - 3,8% e -4,3-0% para creatinina serica, glicose, CK, Ca2+ e Na+. Nos Paises Baixos, as medias / medianas em geral foram de 1,1% (DE=2,0%). O intercambio dos valores atribuidos aos materiais EQA, comutaveis, foi de grande ajuda para a harmonizacao e padronizacao dos ensaios medicos na Argentina e para revelar o potencial futuro de harmonizacao e padronizacao. Esses resultados demonstram as claras que a rastreabilidade metrologica dos resultados dos testes na Argentina esta de acordo com o esperavel; a dispersao entre laboratorios ainda e muito grande e deveria ser melhorada.

Programa de Evaluación Externa de la Calidad "Prof. Dr. Daniel Mazziotta": una nueva etapa asegurando la mejora continua de la calidad / External Quality Assessment Program "Prof. Dr. Daniel Mazziotta ": a new stage ensuring continuous quality improvement

Las determinaciones de los laboratorios clínicos tienen un papel muy importante en la evaluación, diagnóstico, tratamiento y evolución del estado de salud de las personas. La confiabilidad de sus resultados se logra a través del aseguramiento de la calidad y mejora continua. El Programa de Evaluación Externa de la Calidad "Prof. Dr. Daniel Mazziotta" acompaña a los laboratorios de análisis clínicos desde hace 31 años brindando distintas herramientas para garantizar la calidad analítica. Ofrece los servicios de evaluación externa de la calidad, suministro de material para control de calidad interno para determinaciones en Química Clínica y soluciones para control de instrumental y pruebas de suficiencia. Desde la creación del programa se establecieron objetivos estratégicos a desarrollarse en tres etapas: establecimiento, consolidación y apoyo a la gestión de la calidad. Se genera ahora una nueva etapa, cuyo objetivo final es la acreditación. Como primer paso de este ciclo, se implementó un sistema de gestión de la calidad (SGC) de acuerdo a los requisitos establecidos en la norma argentina IRAM-ISO 9001:2015. En agosto de 2019, el Instituto Argentino de Normalización y Certificación (IRAM), representante en Argentina de la International Organization for Standarization (ISO), certificó que el SGC del programa cumple lo establecido en dicha norma. Su aplicación tiene como objetivo asegurar que los servicios ofrecidos satisfagan las necesidades de los laboratorios clínicos cumpliendo los requisitos legales requeridos y asegurando la mejora continua. El objetivo de este trabajo fue describir las acciones realizadas en la implementación del SGC y la posterior certificación de IRAM-ISO 9001:2015, por el IRAM.

Clinical laboratory determinations have a very important role in the evaluation, diagnosis, treatment and evolution of the health status of people. The reliability of their results is achieved through quality assurance and continuous improvement. The External Quality Assessment Programme Prof. Dr. Daniel Mazziotta has been accompanying clinical analysis laboratories for 31 years offering different tools to ensure analytical quality. It provides the services of external quality assessment, supply of material for internal quality control for determinations in Clinical Chemistry and solutions for instrumental control and sufficiency tests. Since the creation of the program, strategic objectives have been established to be developed in three stages: establishment, consolidation and support for quality management. A new stage is now being generated, whose final objective is accreditation. As a first step of this cycle, a quality management system (QMS) was implemented according to the requirements established in the IRAM Argentina standard-ISO 9001:2015. In August 2019, the Argentine Institute for Standardization and Certification (IRAM), representative in Argentina of the International Organization for Standardization (ISO), certified that the Programme's QMS complies with the provisions of said standard. Its application aims to ensure that the services offered meet the needs of clinical laboratories by fulfilling the legal requirements and ensuring continuous improvement. The objective of this work is to describe the actions carried out in the implementation of the QMS and the subsequent IRAM-ISO 9001: 2015 certification by the IRAM.

As determinações laboratoriais clínicas têm um papel muito importante na avaliação, diagnóstico, tratamento e evolução do estado de saúde das pessoas. A confiabilidade de seus resultados é alcançada através da garantia de qualidade e melhoria contínua. O Programa de Avaliação da Qualidade Externa "Prof. Dr. Daniel Mazziotta" apoia os laboratórios de análises clínicas há 31 anos, oferecendo diferentes ferramentas para garantir a qualidade analítica. Oferece os serviços de: avaliação externa de qualidade, fornecimento de material de controle interno de qualidade para determinações em Química Clínica e soluções para controle instrumental e testes de suficiência. Desde a criação do programa, os objetivos estratégicos foram estabelecidos para serem desenvolvidos em três etapas: estabelecimento, consolidação e suporte para a gestão da qualidade. Uma nova etapa é agora gerada, cujo objetivo final é a Acreditação. Como primeira etapa desse ciclo, um sistema de gestão da qualidade (SGQ) foi implementado de acordo com os requisitos estabelecidos na norma IRAM Argentina - ISO 9001:2015. Em agosto de 2019, o Instituto Argentino de Normalização e Certificação (IRAM), representante na Argentina da Organização Internacional de Normalização (ISO), certificou que o SGC do programa está em conformidade com as disposições da referida norma. Sua aplicação visa garantir que os serviços oferecidos satisfaçam as necessidades dos laboratórios clínicos, atendendo aos requisitos legais exigidos e garantindo a melhoria contínua. O objetivo deste trabalho é descrever as ações realizadas na implementação do SGQ e a subsequente certificação da IRAM-ISO 9001:2015, pela IRAM.