| 21. |
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| 22. |
- Bäcklund, Nils, et al.
(författare)
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Salivary cortisol and cortisone in diagnosis of Cushing's syndrome - a comparison of six different analytical methods
- 2023
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter. - 1434-6621 .- 1437-4331. ; 61:10, s. 1780-1791
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Salivary cortisol and cortisone at late night and after dexamethasone suppression test (DST) are increasingly used for screening of Cushing's syndrome (CS). We aimed to establish reference intervals for salivary cortisol and cortisone with three liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques and for salivary cortisol with three immunoassays (IAs), and evaluate their diagnostic accuracy for CS.Methods: Salivary samples at 08:00 h, 23:00 h and 08:00 h after a 1-mg DST were collected from a reference population (n=155) and patients with CS (n=22). Sample aliquots were analyzed by three LC-MS/MS and three IA methods. After establishing reference intervals, the upper reference limit (URL) for each method was used to calculate sensitivity and specificity for CS. Diagnostic accuracy was evaluated by comparing ROC curves.Results: URLs for salivary cortisol at 23:00 h were similar for the LC-MS/MS methods (3.4-3.9 nmol/L), but varied between IAs: Roche (5.8 nmol/L), Salimetrics (4.3 nmol/L), Cisbio (21.6 nmol/L). Corresponding URLs after DST were 0.7-1.0, and 2.4, 4.0 and 5.4 nmol/L, respectively. Salivary cortisone URLs were 13.5-16.6 nmol/L at 23:00 h and 3.0-3.5 nmol/L at 08:00 h after DST. All methods had ROC AUCs =0.96.Conclusions: We present robust reference intervals for salivary cortisol and cortisone at 08:00 h, 23:00 h and 08:00 h after DST for several clinically used methods. The similarities between LC-MS/MS methods allows for direct comparison of absolute values. Diagnostic accuracy for CS was high for all salivary cortisol and cortisone LC-MS/MS methods and salivary cortisol IAs evaluated.
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| 23. |
- Bölenius, Karin, et al.
(författare)
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Minor improvement of venous blood specimen collection practices in primary health care after a large-scale educational intervention
- 2013
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1434-6621 .- 1437-4331. ; 51:2, s. 303-310
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Tidskriftsartikel (refereegranskat)abstract
- Background: Venous blood specimen collection is a common health care practice that has to follow strict guidelines, non-compliance among sampling staff may compromise patient safety. We evaluated a large-scale 2 h educational intervention that emphasised guideline adherence to assess possible improvements of venous blood specimen collection practices.Methods: Blood specimen haemolysis is usually caused by inadequate venous blood specimen collection and handling, reflecting overall pre-analytical handling. We monitored haemolysis of serum samples with haemolysis index corresponding to ≥150 mg/L of free haemoglobin for specimens sent from 11 primary health care centres and analysed on a Vitros 5,1 clinical chemistry analyser before (2008, n=6652 samples) and after (2010, n=6121 samples) the intervention.Results: The total percentage of haemolysed specimens was 11.8% compared to 10.5% (p=0.022) before the intervention. As groups, rural primary health care centres demonstrated a significant reduction [Odds ratios (OR)=0.744] of haemolysed specimens after intervention, whereas urban primary health care centres demonstrated a significant increase (OR=1.451) of haemolysis.Conclusions: A large-scale 2 h educational intervention to make venous blood specimen collection staff comply with guideline practices had minor effects on collection practices. Educational interventions may be effective in wards/care centres demonstrating venous blood specimen collection practices with larger deviations from guidelines.
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| 24. |
- Börjel, Anna K., et al.
(författare)
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Novel mutations in the 5'-UTR of the FOLR1 gene
- 2006
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Ingår i: Clinical Chemistry and Laboratory Medicine. - 1434-6621 .- 1437-4331. ; 44:2, s. 161-167
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Tidskriftsartikel (refereegranskat)abstract
- We have previously reported two novel mutations in the 5'-untranslated region (UTR) of the gene for folate receptor-alpha (FOLR1). In our search for additional mutations, 92 patient samples with elevated levels of homocysteine were screened by single-strand conformation polymorphism (SSCP) between nt -425 and -782, and -712 and -1110. Between nt -425 and -782 we did not find any mutations. Between nt -712 and -1110 there were three novel mutations. One subject had two mutations very close to each other, c.-856C>T and c.-921T>C. Two subjects had a c.-1043G>A mutation. To get an idea of the prevalence of FOLR1 mutations in an unselected population, we also screened 692 healthy school children for mutations. In this cohort, between nt -188 and +272 we discovered one novel mutation, a single nucleotide substitution, c.-18C>T, in addition to five children with the 25-bp deletion mutation previously described by us. Thus, so far we have discovered six novel mutations in the 5'-UTR region of the gene for folate receptor-alpha. We genotyped all 17 subjects with a FOLR1 mutation for the methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism, and developed new single-nucleotide polymorphism (SNP) genotyping protocols for MTHFR 1298A>C and 1793G>A utilising Pyrosequencing technology. None of the 17 subjects had the 677TT genotype, which ruled out this as a cause of elevated homocysteine levels, which was observed in some of the subjects. Further studies of mutations in the 5'-UTR of FOLR1, and in particular of their interplay with folate intake status, are warranted.
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| 25. |
- Cadamuro, Janne, et al.
(författare)
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Preanalytical quality improvement - an interdisciplinary journey, on behalf of the European Federation for Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for Preanalytical Phase (WG-PRE)
- 2022
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter. - 1434-6621 .- 1437-4331. ; 60:5, s. 662-668
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Tidskriftsartikel (refereegranskat)abstract
- Since the beginning of laboratory medicine, the main focus was to provide high quality analytics. Over time the importance of the extra-analytical phases and their contribution to the overall quality became evident. However, as the initial preanalytical processes take place outside of the laboratory and mostly without its supervision, all professions participating in these process steps, from test selection to sample collection and transport, need to engage accordingly. Focusing solely on intra-laboratory processes will not be sufficient to achieve the best possible preanalytical quality. The Working Group for the Preanalytical Phase (WG-PRE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has provided several recommendations, opinion papers and scientific evidence over the past years, aiming to standardize the preanalytical phase across Europe. One of its strategies to reach this goal are educational efforts. As such, the WG-PRE has organized five conferences in the past decade with the sole focus on preanalytical quality. This year's conference mainly aims to depict the views of different professions on preanalytical processes in order to acquire common ground as basis for further improvements. This article summarizes the content of this 6th preanalytical conference.
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| 26. |
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| 27. |
- Clarin, M., et al.
(författare)
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Detection of subarachnoid haemorrhage with spectrophotometry of cerebrospinal fluid - a comparison of two methods
- 2022
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1434-6621 .- 1437-4331. ; 60:7, s. 1053-1057
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Spectrophotometric absorption curve analysis of cerebrospinal fluid (CSF) for oxyhaemoglobin and bilirubin is necessary to accurately diagnose subarachnoid haemorrhage (SAH) in patients with typical symptoms but with negative findings on X-ray examinations. In this study, we evaluated the performance of two methods for interpreting absorption curves; one method from the United Kingdom National External Quality Assessment Service (UK-NEQAS) and the other from the national quality assurance programme in Sweden (Equalis). Methods Consecutive absorbance curves (n=336) were interpreted with two different methods, and their performance was compared to the diagnosis as stated in the patient records. Results The UK-NEQAS method displayed equal sensitivity to the Equalis method, but the specificity of the UK-NEQAS method was significantly higher than the Equalis method resulting in fewer false positive results. For UK-NEQAS, a positive predictive value (PPV) of 84.6% and a negative predictive value (NPV) of 99.7% were observed, whereas the Equalis method had a PPV of 27.5% and an NPV of 99.7%. Conclusions The semi-automated method based on the guidelines from UK-NEQAS provides an efficient and correct interpretation of absorbance curves with short turn-around times. We propose using this method for the routine interpretation of CSF spectrophotometric curves.
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| 28. |
- Collinson, P., et al.
(författare)
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Cardiac troponin measurement at the point of care: educational recommendations on analytical and clinical aspects by the IFCC Committee on Clinical Applications of Cardiac Bio-Markers (IFCC C-CB)
- 2023
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1434-6621 .- 1437-4331. ; 61:6, s. 989-998
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Tidskriftsartikel (refereegranskat)abstract
- The International Federation of Clinical Chemistry and Laboarator Medicine (IFCC) Committee on Clinical Applications of Cardiac Bio-Markers (C-CB) has provided evidence-based educational resources to aid and improve the understanding of important analytical and clinical aspects of cardiac biomarkers. The present IFCC C-CB educational report focuses on recommendations for appropriate use, analytical performance, and gaps in clinical studies related to the use of cardiac troponin (cTn) by point of care (POC) measurement, often referred to as a point of care testing (POCT). The use of high-sensitivity (hs)-cTn POC devices in accelerated diagnostic protocols used in emergency departments or outpatient clinics investigating acute coronary syndrome has the potential for improved efficacy, reduction of length of stay and reduced costs in the health care system. POCT workflow integration includes location of the instrument, assignment of collection and testing responsibility to (non-lab) staff, instrument maintenance, in-service and recurrent training, quality control, proficiency assessments, discrepant result trapping, and troubleshooting and inventory management.
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| 29. |
- Cornes, Michael, et al.
(författare)
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Order of blood draw : Opinion Paper by the European Federation for Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for the Preanalytical Phase (WG-PRE)
- 2017
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1434-6621 .- 1437-4331. ; 55:1, s. 27-31
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Tidskriftsartikel (refereegranskat)abstract
- It has been well reported over recent years that most errors within the total testing process occur in the pre-analytical phase (46%-68.2%), an area that is usually outside of the direct control of the laboratory and which includes sample collection (phlebotomy). National and international (WHO, CLSI) guidelines recommend that the order of draw of blood during phlebotomy should be blood culture/sterile tubes, then plain tubes/gel tubes, then tubes containing additives. This prevents contamination of sample tubes with additives from previous tubes that could cause erroneous results. There have been a number of studies recently looking at whether order of draw remains a problem with modern phlebotomy techniques and materials, or it is an outdated practice followed simply because of historical reasons. In the following article, the European Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Preanalytical Phase (EFLM WG-PRE) provides an overview and summary of the literature with regards to order of draw in venous blood collection. Given the evidence presented in this article, the EFLM WG-PRE herein concludes that a significant frequency of sample contamination does occur if order of draw is not followed during blood collection and when performing venipuncture under less than ideal circumstances, thus putting patient safety at risk. Moreover, given that order of draw is not difficult to follow and knowing that ideal phlebotomy conditions and protocols are not always followed or possible, EFLM WG-PRE supports the continued recommendation of ensuring a correct order of draw for venous blood collection.
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| 30. |
- Damoiseaux, Jan, et al.
(författare)
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An international survey on anti-neutrophil cytoplasmic antibodies (ANCA) testing in daily clinical practice
- 2018
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter. - 1434-6621 .- 1437-4331. ; 56:10, s. 1759-1770
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Tidskriftsartikel (refereegranskat)abstract
- Background: Detection of anti-neutrophil cytoplasmic antibodies (ANCA) is important for the diagnosis of the ANCA-associated vasculitides (AAV). For AAV, especially ANCA directed against myeloperoxidase (MPO) and proteinase 3 (PR3) are most relevant. ANCA with less well-defined specificities may, however, also be detected in other inflammatory and non-inflammatory conditions.Methods: A questionnaire, initiated by the European Autoimmunity Standardisation Initiative (EASI), was used to gather information on methods and testing algorithms used for ANCA in clinical laboratories of 12 European countries (EASI survey).Results: Four hundred and twenty-nine responses were included in the EASI survey analysis which revealed differences within countries and between countries. Laboratories overall were poor in adherence to international consensus on ANCA testing. Substantial variation was observed with respect to the use of ANCA indirect immunofluorescence (IIF) in the algorithm, application of distinct methods for MPO- and PR3-ANCA, the daily availability of new ANCA results, and interpretation of test results.Conclusions: Awareness of these differences may stimulate further harmonization and standardization of ANCA testing. This may be promoted by an update of the international ANCA consensus and the introduction of international standards.
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