Documenting metrological traceability as intended by ISO 15189:2012: A consensus statement about the practice of the implementation and auditing of this norm element.

ISO15189:2012 requires medical laboratories to document metrological traceability of their results. While the ISO17511:2003 standard on metrological traceability in laboratory medicine requires the use of the highest available level in the traceability chain, it recognizes that for many measurands there is no reference above the manufacturer's selected measurement procedure and the manufacturer's working calibrator. Some immunoassays, although they intend to measure the same quantity and may even refer to the same reference material, unfortunately produce different results because of differences in analytical selectivity as manufacturers select different epitopes and antibodies for the same analyte. In other cases, the cause is the use of reference materials, which are not commutable. The uncertainty associated with the result is another important aspect in metrological traceability implementation. As the measurement uncertainty on the clinical samples is influenced by the uncertainty of all steps higher in the traceability chain, laboratories should be provided with adequate and appropriate information on the uncertainty of the value assignment to the commercial calibrators that they use. Although the between-lot variation in value assignment will manifest itself as part of the long-term imprecision as estimated by the end-user, information on worst-case to be expected lot-lot variation has to be communicated to the end-user by the IVD provider. When laboratories use ancillary equipment that potentially could have a critical contribution to the reported results, such equipment needs verification of its proper calibration and criticality to the result uncertainty could be assessed by an approach based on risk analysis, which is a key element of ISO15189:2012 anyway. This paper discusses how the requirement for metrological traceability as stated in ISO15189 should be met by the medical laboratory and how this should be assessed by accreditation bodies.

Accreditation process in European countries - an EFLM survey.

BACKGROUND: Accreditation is a valuable resource for medical laboratories. The development of quality systems based on ISO 15189 has taken place in many laboratories in the European countries but data about accreditation remain scarce. The EFLM Working Group "Accreditation and ISO/CEN standards" conducted a survey that reviews the current state of the accreditation process in European countries. METHODS: An on-line questionnaire was addressed to delegates of 39 EFLM scientific societies in March 2014. One answer by country was taken into account. The survey was dealing with mandatory status, number of accredited medical laboratories in each country, possibility of flexible scope and concerned medical fields. The status of point-of-care testing (POCT) in each country was also studied. RESULTS: Twenty-nine responses (74%) were registered. All the assessed countries (100%) have begun an accreditation process in various ways. All the national accreditation bodies (NAB) offer or are working to offer an ISO 15189 accreditation. The accreditation process most often concerns all phases of the examination and various medical fields. Medical laboratories are responsible for POCT in 20 (69%) countries. The accreditation process for POCT, according to ISO 15189 and ISO 22870, is also developing. CONCLUSIONS: While there are several variations in the approaches to accreditation of medical laboratories in the European countries, the ISO 15189 accreditation project has been widely accepted. The use of a unique standard and the cooperation among countries due to scientific societies, EFLM, accreditation bodies and EA enable laboratory professionals to move toward uniform implementation of the accreditation concept.

Flexible scope for ISO 15189 accreditation: a guidance prepared by the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group Accreditation and ISO/CEN standards (WG-A/ISO).

The recent revision of ISO15189 has further strengthened its position as the standard for accreditation for medical laboratories. Both for laboratories and their customers it is important that the scope of such accreditation is clear. Therefore the European co-operation for accreditation (EA) demands that the national bodies responsible for accreditation describe the scope of every laboratory accreditation in a way that leaves no room for doubt about the range of competence of the particular laboratories. According to EA recommendations scopes may be fixed, mentioning every single test that is part of the accreditation, or flexible, mentioning all combinations of medical field, examination type and materials for which the laboratory is competent. Up to now national accreditation bodies perpetuate use of fixed scopes, partly by inertia, partly out of fear that a too flexible scope may lead to over-valuation of the competence of laboratories, most countries only use fixed scopes. The EA however promotes use of flexible scopes, since this allows for more readily innovation, which contributes to quality in laboratory medicine. In this position paper, the Working Group Accreditation and ISO/CEN Standards belonging to the Quality and Regulation Committee of the EFLM recommends using an approach that has led to successful introduction of the flexible scope for ISO15189 accreditation as intended in EA-4/17 in The Netherlands. The approach is risk-based, discipline and competence-based, and focuses on defining a uniform terminology transferable across the borders of scientific disciplines, laboratories and countries.

Cardiac biomarkers predict outcome after hospitalisation for an acute exacerbation of chronic obstructive pulmonary disease.

PURPOSE: In chronic obstructive pulmonary disease (COPD), cardiovascular system is involved but less is known about role of specific cardiac biomarkers. We aimed to investigate associations between N-terminal pro B-type natriuretic peptide (NT-proBNP) and troponin T during hospitalisation with 6-month outcome. METHODS: This was a prospective study conducted in consecutive patients hospitalized for an acute exacerbation of COPD. On admission, and at discharge, NT-proBNP and troponin T were measured, and echocardiography was performed. Hospitalisations and mortality were recorded for 6 months after discharge. RESULTS: We included 127 patients (70 ± 10 years, 70% men, GOLD III/IV 87%). Left ventricular dysfunction was detected in 70 (55%) patients and diastolic dysfunction was the most common type (53 patients-42%). NT-proBNP and troponin T were elevated on admission in 60% and 36%, and at discharge in 28% and 19% of patients. During follow-up, 53 (42%) patients were hospitalized and 17 (13%) patients died. In Kaplan Meier analysis of survival curves, NT-proBNP on admission distinguished between deceased and surviving patients (p=0.011) whilst troponin T at discharge separated hospitalized and non-hospitalized patients (p=0.017). The adjusted Cox proportional hazard model confirmed these findings: discharge troponin T predicted hospitalisations (hazard ratio 2.89, 95% confidence interval 1.13-7.36) and admission NT-proBNP predicted mortality (hazard ratio 4.20, 95% confidence interval 1.07-14.01). CONCLUSIONS: Elevated NT-proBNP at discharge and troponin T on admission predict outcome in patients hospitalized for an acute exacerbation of COPD.

The regulation of clinical chemistry in Slovenia.

The practice of medical biochemistry in Slovenia includes clinical biochemistry (including toxicology, therapeutic drug monitoring, endocrinology, molecular diagnostics, immunology), hematology and coagulation. To start the vocational medical biochemistry training programme it's necessary to have a completed university degree (second cycle) in pharmacy, chemistry, biochemistry, medicine or other relevant university study and 1 year supervised practical training in medical laboratories, completed with mandatory state exam at Ministry of Health. The duration of vocational training programme is 4 years and is completed with final exam. The title after passed final examination is Medical biochemistry specialist. In October 2005 EC4 (Communities Confederation of Clinical Chemistry and Laboratory Medicine) approved Equivalence of standards of Slovenian national standards for medical biochemistry specialists. Since 2006 it is mandatory to be registered and to have valid license for medical biochemistry specialists and other professionals in laboratory medicine with at least university degree (second cycle) of education. Laboratory medicine in Slovenia is regulated globally through the Law of health-care activity and particularly through the Bylaw of laboratory medicine. The latter is based on standard ISO 15189, ratified in 2004. The Bylaw envisages granting working license to laboratories, valid for 5 years period. Granting of working licenses is ongoing process and first licenses have been granted in 2009. Important improvement toward the quality requirements for medical laboratories can be observed in the last 5 years. Parallel with the Bylaw of medical laboratories, Slovenian Accreditation (SA), the legal national accreditation body, started the initiative for accreditation of medical laboratories according to ISO 15189. It is in the implementation phase.

Human brain cathepsin H as a neuropeptide and bradykinin metabolizing enzyme.

Highly purified human brain cathepsin H (EC 3.4.22.16) was used to study its involvement in degradation of different brain peptides. Its action was determined to be selective. On Leu-enkephalin, dynorphin (1-6), dynorphin (1-13), alpha-neoendorphin, and Lys-bradykinin, it showed a preferential aminopeptidase activity by cleaving off hydrophobic or basic amino acids. It showed no aminopeptidase activity on bradykinin, which has Pro adjacent to its N-terminal amino acid, on neurotensin with blocked N-terminal amino acid, or on dermorphin with second amino acid D-alanine. After prolonged incubation, cathepsin H acted as an endopeptidase. Dermorphin and dynorphin (1-13) were cleaved at bonds with Phe in the P2 position, while dynorphin (1-6), alpha-neoendorphin, bradykinin and Lys-bradykinin were cleaved at bonds with Gly in the P2 position. Further on, it was shown that human brain cathepsin H activity could be controlled in vivo by cystatin C in its full-length form or its [delta1-10] variant, already known to be co-localized in astrocytes, since the Ki values for the inhibition are in the 10(-10) M range.