Optimized procedures for testing plasma metanephrines in patients on hemodialysis.

Diagnosis of pheochromocytomas and paragangliomas in patients receiving hemodialysis is troublesome. The aim of the study was to establish optimal conditions for blood sampling for mass spectrometric measurements of normetanephrine, metanephrine and 3-methoxytyramine in patients on hemodialysis and specific reference intervals for plasma metanephrines under the most optimal sampling conditions. Blood was sampled before and near the end of dialysis, including different sampling sites in 170 patients on hemodialysis. Plasma normetanephrine concentrations were lower (P < 0.0001) and metanephrine concentrations higher (P < 0.0001) in shunt than in venous blood, with no differences for 3-methoxytyramine. Normetanephrine, metanephrine and 3-methoxytyramine concentrations in shunt and venous blood were lower (P < 0.0001) near the end than before hemodialysis. Upper cut-offs for normetanephrine were 34% lower when the blood was drawn from the shunt and near the end of hemodialysis compared to blood drawn before hemodialysis. This study establishes optimal sampling conditions using blood from the dialysis shunt near the end of hemodialysis with optimal reference intervals for plasma metanephrines for the diagnosis of pheochromocytomas/paragangliomas among patients on hemodialysis.

[How did the private labs fit onto COVID-19 crisis?] / Comment les laboratoires de biologie médicale privés français se sont adaptés à la crise de la COVID-19 ?

Confronted with the COVID-19 crisis, healthcare professionals have had to tackle an epidemic crisis of a huge magnitude for which they were not prepared. Medical laboratories have been on the front line, from collecting samples to performing the analysis required to diagnose this new pathology. Responding to the needs and to the urgency of the situation, the authorities relied on the network of private laboratories. In France, private laboratory medicine represents 70% of overall activity, and with a network of more than 4,000 local laboratories, private laboratory medicine has been the cornerstone of the « screen-trace-isolate ¼ strategy. This article gives feedback from private laboratory medicine professionals, directly involved in the reorganization carried out at the pre-analytical, analytical and post-analytical stages, during the crisis from March to October 2020.

[Recommendations for urinary organic acids analysis]. / Recommandations concernant l'analyse des acides organiques urinaires.

Biochemical diagnosis of hereditary metabolic diseases requires the detection and simultaneous identification of a large number of compounds, hence the interest in metabolic profiles. Organic acid chromatography allows the identification of several hundred compounds and the quantification of the main molecules of interest. As part of the accreditation process for medical biology examinations according to standard NF EN ISO 15189, the group from the French society for inborn errors of metabolism (SFEIM) recommends an approach to accredit organic acid chromatography. Validation parameters and recommendations are discussed in this specific framework.

[Improvement of the pre-examination phase of medical biology exams at the Henri Mondor University Hospitals: a pilot study]. / Une étude pilote pour l'amélioration de l'étape pré-analytique des examens de biologie médicale pris en charge au sein des hôpitaux universitaires Henri Mondor.

The medical and university department of biology pathology at Henri Mondor hospital in Créteil has been engaged in an NF EN ISO 15189 accreditation process since 2014. One of the elements of this process concerns the quality of handling of samples and their transportation to laboratories, including the implementation place requires fighting against pre-examination non-conformities, which are the source of many dysfunctions. The pre-examination group has implemented several actions in a targeted care service. Thanks to these, the rate of non-conformities has halved in 18 months. In parallel, a work project targeting student nurses on internship was born to follow up on the results of a statistical study carried out by the pre-examination group on non-conformities. The objective of the project was to include nursing students on internship in a full support course on good sampling practices and pre-analytical non-conformities. This was based on the realization of two knowledge quizzes (before and after training), theoretical training, and visits to several laboratories. This study lasted 10 months with the participation of 37 students. The results showed a marked improvement in knowledge of pre-analytics as well as total satisfaction of all students. Our approach has helped to better understand the needs of laboratories and demonstrates the usefulness of training students in good sampling practices in order to ensure better patient care as well as an improvement in their comfort and well-being.

[Ethics and confidentiality of a patient in a medical biology laboratory]. / L'éthique et la confidentialité du patient au laboratoire de biologie médicale.

Confidentiality is based on principles of deontology and ethics, which are included in French regulations and supported by the professional orders. It contributes to the respect and dignity of the patient. If this consideration of the human person is old, it has been updated to build the framework imposed by the accreditation of medical biology laboratories. Confidentiality is thus reflected in a charter of ethics, a model of which we propose here. It reflects the commitments of healthcare professionals in the processing of biological samples from patients. Confidentiality is thus applied, in a practical way, at each phase of the laboratory's activity. In the pre-analytical phase, it organizes the reception of the patient and the taking of samples, taking into account the particular case of minors. In the analytical phase, confidentiality imposes limited access to the technical premises and the organization of the flow of personnel from outside the laboratory. Finally, in the post-analytical phase, the reporting of results is regulated, depending on the type of analyses performed and the person to whom the results are to be reported (patient or prescriber). The particular case of spermiology illustrates all these points. Finally, during these phases of sample processing, document management is also a matter of confidentiality and data protection. Confidentiality is essential to the functioning of a health care structure, but it is restrictive in its day-to-day implementation. Nevertheless, it must be combined with an awareness of all staff to address the ethical issue of human dignity.

[Recommendations for acylcarnitine profile analysis]. / Recommandations concernant l'analyse du profil des acylcarnitines.

Biochemical diagnosis of hereditary metabolic diseases requires the detection and simultaneous identification of a large number of compounds, hence the interest in metabolic profiles. Acylcarnitine profile allows the identification and quantification of more than thirty compounds. As part of the accreditation process for medical biology examinations according to standard NF EN ISO 15189, the group from SFEIM recommends an approach to accredit acylcarnitine profile. Validation parameters and recommendations are discussed in this specific framework.

Laboratory testing of extravascular body fluids: National recommendations on behalf of the Croatian Society of Medical Biochemistry and Laboratory Medicine. Part II - Synovial fluid.

Joint diseases are conditions with an often progressive and generally painful nature affecting the patient's quality of life and, in some cases, requiring a prompt diagnosis in order to start the treatment urgently. Synovial fluid (SF) laboratory testing is an important part of a diagnostic evaluation of patients with joint diseases. Laboratory testing of SF can provide valuable information in establishing the diagnosis, be a part of a patient's follow-up and treatment with the purpose of improving the patient's health and quality of life. Synovial fluid laboratory testing is rarely performed in Croatian medical biochemistry laboratories. Consequently, procedures for SF laboratory testing are poorly harmonized. This document is the second in the series of recommendations prepared by the members of the Working group for extravascular body fluid samples of the Croatian Society of Medical Biochemistry and Laboratory Medicine. It addresses preanalytical, analytical, and postanalytical issues and the clinical significance of tests used in SF laboratory testing with the aim of improving the value of SF laboratory testing in the diagnosis of joint diseases and assisting in the achievement of national harmonization. It is intended for laboratory professionals and all medical personnel involved in synovial fluid collection and testing.

The CRESS checklist for reporting stability studies: on behalf of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for the Preanalytical Phase (WG-PRE).

To ensure that clinical laboratories produce results that are both accurate and of clinical utility it is essential that only samples of adequate quality are analysed. Although various studies and databases assessing the stability of analytes in different settings do exist, guidance on how to perform and report stability studies is lacking. This results in studies that often do not report essential information, thus compromising transferability of the data. The aim of this manuscript is to describe the Checklist for Reporting Stability Studies (CRESS) against which future studies should be reported to ensure standardisation of reporting and easy assessment of transferability of studies to other healthcare settings. The EFLM WG-PRE (European Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Preanalytical Phase) produced the CRESS checklist following a detailed literature review and extensive discussions resulting in consensus agreement. The checklist consists of 20 items covering all the aspects that should be considered when producing a report on a stability study including details of what should be included for each item and a rationale as to why. Adherence to the CRESS checklist will ensure that studies are reported in a transparent and replicable way. This will allow other laboratories to assess whether published data meet the stability criteria required in their own particular healthcare scenario. The EFLM WG-PRE encourage researchers and authors to use the CRESS checklist as a guide to planning stability studies and to produce standardised reporting of future stability studies.

Strict Preanalytical Oral Glucose Tolerance Test Blood Sample Handling Is Essential for Diagnosing Gestational Diabetes Mellitus.

OBJECTIVE: Preanalytical processing of blood samples can affect plasma glucose measurement because ongoing glycolysis by cells prior to centrifugation can lower its concentration. In June 2017, ACT Pathology changed the processing of oral glucose tolerance test (OGTT) blood samples for pregnant women from a delayed to an early centrifugation protocol. The effect of this change on the rate of gestational diabetes mellitus (GDM) diagnosis was determined. RESEARCH DESIGN AND METHODS: All pregnant women in the Australian Capital Territory (ACT) are recommended for GDM testing with a 75-g OGTT using the World Health Organization diagnostic criteria. From January 2015 to May 2017, OGTT samples were collected into sodium fluoride (NaF) tubes and kept at room temperature until completion of the test (delayed centrifugation). From June 2017 to October 2018, OGTT samples in NaF tubes were centrifuged within 10 min (early centrifugation). RESULTS: A total of 7,509 women were tested with the delayed centrifugation protocol and 4,808 with the early centrifugation protocol. The mean glucose concentrations for the fasting, 1-h, and 2-h OGTT samples were, respectively, 0.24 mmol/L (5.4%), 0.34 mmol/L (4.9%), and 0.16 mmol/L (2.3%) higher using the early centrifugation protocol (P < 0.0001 for all), increasing the GDM diagnosis rate from 11.6% (n = 869/7,509) to 20.6% (n = 1,007/4,887). CONCLUSIONS: The findings of this study highlight the critical importance of the preanalytical processing protocol of OGTT blood samples used for diagnosing GDM. Delay in centrifuging of blood collected into NaF tubes will result in substantially lower rates of diagnosis than if blood is centrifuged early.

[Contamination of urine collected for cytobacteriological examination: situation in a university hospital in Morocco]. / Contamination des urines prélevées pour examen cytobactériologique : situation dans un centre hospitalier universitaire au Maroc.

The pre-analytical step of the cytobacteriological examination of urine (CBEU) is one of the most critical in microbiology. The objectives of our study were to determine the rate of urinary contamination and to analyze the factors that would facilitate this in order to propose solutions to this problem. METHOD: This is a 26-month descriptive study including all CBEU requests to our laboratory. Urine was treated in accordance with the recommendations of the medical microbiology recommendations. Urine was considered contaminated in the case of polymorphic culture with at least three different types of germs with a count from 103 CFU/mL. RESULTS: We collected 16,412 CBEU requests. Urine was contaminated in 4,830 cases (29.43%). Of the contaminated urine, 39.23% (n=1,895) was from emergency departments, 79.44% (n=3,837) was collected in the middle of the stream, 69.83% (n=3,373) was from a female patient and 16.34% (n=789) was from children under the age of 5. DISCUSSION AND CONCLUSION: To reduce urine contamination, quality instructions describing sampling procedures should be available and samples in the middle of the stream and through the collection adhesive bags should be replaced by sus-pubic puncture samples in children, whenever the profit/risk ratio of this method is favourable.

[Mastering the analytical process of the Complete Blood Count: how and why?] / Maîtrise du processus analytique de la Numération Formule Sanguine : comment et pourquoi ?

This is a prospective study realized at the level of the hematology department and blood transfusion center of the University Hospital Center (CHU) of Dr Ben Badis of Constantine and spread out over a period of one year (from January 1st to December 31st). The work focused on the analytical processes mastery of the NFS needs a compulsory step concerning technical and organizational laboratory skills respecting the ISO 15189 laws going through a mastery of support processes (humain resourses, informatics, materials, documents, management) indispensable for the good function of analytic proceedings, a performance evaluation of the hematology analyzer Advia (2120 I and II and 560) and quality control management (intern, extern). The analytic performance evaluation of Advia gives reliable results reproductible and stable for use of the routine automatisation good inter-machine correlation and laboratory performance in terms of the quality extern evaluation with military hospital laboratory.

Optimization of the Preanalytical Phase by Estimating Serum Indices Using an Automated Classifier.

BACKGROUND: Most laboratory errors occur in the preanalytical phase. Among the most common preanalytical errors are interferences due to hemolysis, lipemia, and icterus. Our objective was to evaluate a serum interference estimation methodology by the RSD classifier, to identify other biochemical parameters affected by preanalytical interferences, and to determine the economic impact of its implementation. METHODS: The serum indices of 65,529 requests measured by the RSD system and by the analytical determination on the Cobas 711 or Cobas 8000 platforms were collected. We proceeded to the search for association patterns between the serum indices and laboratory analytical tests using data mining techniques. The influence of the preanalytical interferences was evaluated in 91 laboratory tests that include biochemistry, immunoassay, and coagulation. The savings estimation after the implementation of this methodology was made by time series models. RESULTS: The evaluation of the generated model showed compatibilities between the methods used (94.4% accuracy). The implementation of a protocol for serum indices estimation by the RSD would avoid the unnecessary analysis of the tests which are affected by interferences, achieving an estimated annual savings of €10,561. In addition, it allowed the estimation of bilirubin values which would add an annual savings of €4,900 in our laboratory. On the other hand, data mining techniques have allowed us to identify the following laboratory tests affected by hemolysis which are not usually considered in laboratories: iron, transferrin, fibrinogen, and alkaline phosphatase. CONCLUSIONS: The RSD classifier is an efficient estimation method of serum indices and it allows the estimation of bilirubin values. The implementation of this methodology in our laboratory could lead to an estimated annual savings of more than €15,000 without increasing response times. Iron, alkaline phosphatase, transferrin, and fibrinogen should be included in the evaluated procedure.

Improvement of Blood Samples Preanalytic Management Alters the Clinical Results of Glucose Values: Population Study.

BACKGROUND: Prolonged time elapsing between the blood drawing and separation of the cell mass may result in decreased sample glucose levels due to continuous glycolysis. This can lead to underdiagnoses of hyperglycemic states and overdiagnosis of hypoglycemia. We aimed to evaluate the clinical impact of shortened transit time and earlier centrifugation of laboratory specimens on reported glucose results and diagnosis of clinically significant hypoglycemia (<50 mg/dL) or elevated glucose levels (>100 mg/dL). METHODS: We assessed all fasting-serum glucose tests from the adult population (190 767 subjects) without known diabetes residing in Southern Israel. Before and after intervention periods were compared: 268 359 blood tests were performed during 2009-2010, and 317 336 during 2012-2013. RESULTS: While glucose levels were 94.17 mg/dL ± 14.12 in 2012-2013 versus 83.53 mg/dL ± 14.50 in 2009-2010 (12.75% ± 0.88 increase, P < .001), the difference in glycated hemoglobin levels was statistically significant but clinically negligible: 5.84% ± 0.56 in 2012-2013 versus 5.88% ± 0.56 in 2009-2010 (0.53% ± 0.78 decrease, P < .01). There was an increased likelihood of a glucose result to be above 100 mg/dL following intervention: 9.80% versus 25.90%, P < .001. For clinics distanced over 40 km from the laboratory, age-adjusted odds ratio value was 1.26 (95% CI 1.13, 1.41). The proportion of samples with hypoglycemia values decreased from 0.33% to 0.03% (P < .001). CONCLUSIONS: We demonstrated an important change in glucose values over a two-year period following an improvement of the preanalytic processes. The intervention was related to an increase in the frequency of hyperglycemia results and a decrease in the number of hypoglycemia results. Future administrative projects should consider clinical consequences with involvement of all relevant stakeholders.

Standardization of the preanalytical phase of DNA extraction from fixed tissue for next-generation sequencing analyses.

Next-generation sequencing (NGS) analyses on DNA derived from archived Formalin-Fixed Paraffin-Embedded (FFPE) clinical material can provide a powerful tool in oncology research and clinical diagnostics. Although several studies have established that NGS can be performed using DNA from FFPE tissue, the accuracy and reproducibility of such analyses, as well as their robustness to the biomolecular quality of the samples used, remains a matter of debate. Excellent reviews have recently been published, providing evidence-based best practices for FFPE DNA extraction. Alternative fixatives exist, although their implementation in clinical practice is difficult. In this article, we present (i) a review of fixed tissue DNA preanalytics with a special focus on DNA extraction and fixed tissue sample qualification and (ii) results from comparisons between different methods of DNA extraction from tissue samples that have been fixed or stabilized by different methods, in terms of NGS metrics and different DNA quality metrics.

Quality Control of Preanalytical Handling of Blood Samples for Future Research: A National Survey.

BACKGROUND: Assessment and control of preanalytical handling of blood samples for future research are essential to preserve integrity and assure quality of the specimens. However, investigation is limited on how quality control of preanalytical handling of blood samples is performed by biobanks. METHODS: A questionnaire was sent to all Danish departments of clinical biochemistry, all Danish departments of clinical immunology, the Danish Health Surveillance Institution and the Danish Cancer Society. The questionnaire consisted of questions regarding preanalytical handling of samples for future research. The survey was carried out from October 2018 until the end of January 2019. RESULTS: A total of 22 departments (78%) replied, of which 17 (77%) performed preanalytical quality control of the blood samples. This quality control consisted of patient preparation, temperature surveillance of freezers, maintenance of centrifuges, and visual inspection for hemolysis, lipemia, and sample volume. Automated sample check for hemolysis, icterus, and lipemia interferences was performed by 41% of respondents, not performed by 50% of respondents, and 9% did not answer. The majority (55%) of the participants stated that they had no local standard operating procedure for preanalytical handling of samples for research projects. CONCLUSIONS: The preanalytical phase for blood samples obtained and preserved for future research in Denmark is highly heterogeneous, although many aspects (e.g., hemolysis, which also affects DNA analyses, metabolomics, and proteomics) seems highly relevant to document. Our findings emphasize the need to optimize and standardize best practices for the preanalytical phase for blood samples intended for use in future research projects.

[Metals: common clinical applications in inductively coupled plasma mass spectrometry]. / Métaux : applications cliniques courantes en spectrométrie de masse à plasma à couplage inductif.

Inductively coupled plasma mass spectrometry (ICP-MS) is an analytical technique for inorganic, quantitative, and multi-elemental compounds commonly used in clinical biology. In recent years, it has gradually replaced atomic absorption techniques. It is based on the combination of an ion source formed of an inductively coupled plasma torch by a high-frequency electromagnetic generator, and a mass spectrometer, which allows the separation of ions generated according to their mass and energy. It allows the simultaneous detection of most metal and metalloid elements (about 80, 40 generally). It is extremely sensitive for determining analyte concentrations up to nanograms per liter. ICP-MS is fast and suitable for continued use on different types of biological samples. Its use requires, however, good knowledge of the different types of interferences, whether spectral or non-spectral. This method may require specific adaptations depending on the samples used due to the matrix effect. In this review, we will present the main principles of the realization of dosages, as well as the various devices currently commercialized. It is currently used for the determination of the most critical metals in clinical biochemistry, copper, zinc, and selenium, but also in clinical toxicology and pharmacology.

Pharmacological and analytical interference in hormone assays for diagnosis of adrenal incidentaloma.

Adrenal incidentaloma refers to an asymptomatic adrenal mass detected through an imaging procedure performed for reasons unrelated to adrenal dysfunction or suspected dysfunction. In general, adrenal incidentalomas are non-functioning adrenal adenomas, but in some cases, may require therapeutic intervention: eg., adrenocortical carcinoma, pheochromocytoma, primary aldosteronism, cortisol hypersecretion, or adrenal insufficiency. Hormone assessment is crucial to characterize adrenal incidentaloma. Nowadays, various hormone assay methods are available, such as immunoassay and mass spectrometry. However, there are several pitfalls that should be considered: e.g., circadian rhythm, gender/age dependency, preanalytical and analytical issues, and drug interactions. Pharmacological or analytical interference can lead to false serum concentrations and may result in misinterpretation of results and thus inappropriate treatment. The purpose of this review was to study the main interferences that may be observed in the different tumor types of adrenal incidentalomas in order to help physicians in their clinical decision-making and for the overall benefit of patients.