Hintergrund: Angesichts der komplexen föderalen und nationalen Struktur des Impfwesens in Deutschland wurde im Jahr 2009 die 1. Nationale Impfkonferenz (NIK) von Rheinland-Pfalz initiiert, um eine nationale Plattform zum Austausch von Entscheidungsträgern, Impfexperten und verschiedenen Impfakteuren zu ermöglichen. Dank des großen Erfolgs der Konferenz und zur Fortsetzung des gemeinsamen politischen Bekenntnisses zur Impfprävention entschied die Gesundheitsministerkonferenz (GMK), die Impfkonferenzen im Abstand von 2 Jahren zu verstetigen. Jede Nationale Impfkonferenz (NIK) bietet einen breiten Austausch zu aktuellen Impfthemen und regionalen Best Practice-Beispielen, dabei werden neue Konzepte angestoßen. Seit dem Jahr 2011 werden die Konferenzen in alphabetischer Reihenfolge der Bundesländer ausgerichtet.

Background: External quality assessment (EQA)-services have been performed through different organizations for many years. Recently the need for new kinds of modern and even integrated EQA-services became clear, in particularly to empower medical laboratories for their future tasks, such as contribution to the development and implementation, as well as participation in global health-care policies. Therefore, we have developed the Empower project. Methods: The Empower project comprises the following 4 pillars: (i) master comparisons with panels of single donation sera, (ii) virtual EQA-1 and (iii) virtual EQA-2 based on monitoring of patient percentiles and internal quality control (IQC) data across laboratories, and (iv) conceptual and statistical education to share a common vision on analytical quality. Twenty laboratories from each of the 5 main manufacturers are desirable for a successful project. It is important that in all laboratories homogeneous systems are used: instrument, calibrator and reagent should be from the same manufacturer. Participation of the manufacturers’ application laboratories is also encouraged. Results: Master comparisons give laboratories a calibration fix-point and information on the basic quality of their assays and their own performance. This is also beneficial for the manufacturers, since the results will evidence the inherent quality of the systems at the side of the manufacturers and the reproducibility of that quality in the laboratories. The patient percentile monitoring serves as a real-time quality indicator for the daily performance, while patient- and IQC-monitoring establish evidence about the mid- to long-term variation of instrument-calibrator-reagent combinations, backed-up by information from other laboratories of the peer group. In the case of an unacceptable lot-to-lot variation, laboratories have a basis for factorizing. The link between patient- and IQC-data strengthens the quality management and quality assurance system of the laboratories. The Empower project can also assess all major bias components, like manufacturer, instrument, module, lot and calibration. Due to this laboratories know their own calibration status compared to the calibration status of a reference measurement procedure or peer group and they can monitor the module, lot and calibration stability. Conclusions: The Empower project adds on to the knowledge of the reasons for assay variation, strengthens the laboratories’ position in claims versus manufacturers and creates a tool for developing realistic quality goals and for strengthening the physician/laboratory interface by transparent communication on performance. It delivers data on the performance of assays from other manufacturers that may help laboratories in decisions on the acquisition of new instruments. Last but not least, the education by EQA-organizers on analytical quality, backed-up by evidence created by the Empower project, will allow a common understanding between manufacturers and laboratories about realistic performance specifications and the needed quality management and quality assurance activities.

Background/Method: The analytical validity of free testosterone (FTe) analog immunoassays is subject to much controversy. We revisited the validation of 4 analog assays and 1 FTe calculation procedure with a metrologically traceable reference measurement procedure (RMP) based on ultrafiltration and isotope dilution-mass spectrometry for direct measurement of Te in the ultrafiltrate. To this end, we performed split-sample measurements of 40 male sera.Results: Deming regression showed that 3 of the immunoassays had moderate to good correlation (0.8474 less than or equal to r less than or equal to 0.9241) with the RMP; however, the slope was markedly below 1. The FTe calculation procedure was in good agreement with this result. The Sy/x values for all assays were higher than the combined imprecision values, which indicate their susceptibility to matrix-related effects.Conclusions: The study demonstrated substantial differences in analytical quality of FTe assays; however, the results suggested that after extending the validation with a larger variety of samples, recalibration of some analog assays might be worth further investigation. (C) 2004 The Canadian Society of Clinical Chemists. All rights reserved.

(O) under bar(b) under bar(j) under bar(e) under bar(c) under bar(t) under bar(i) under bar(v) under bar(e) under bar: The aim of this Study was to investigate serum Ionized magnesium (i-Mg) levels in patients with various stages of renal failure and to compare them with serum total magnesium (t-Mg). (M) under bar(e) under bar(t) under bar(h) under bar(o) under bar(d) under bar(s) under bar (a) under bar(n) under bar(d) under bar (m) under bar(e) under bar(t) under bar(h) under bar(o) under bar(d) under bar(s) under bar: We Studied 69 nondiabetic ambulatory patients not receiving diuretics, polystyrene sulfonate or NaHCO3. Serum i-Mg was measured with an ion-selective electrode and serum t-Mg by ion chromatography. Renal function was determined by the creatinine clearance (C-Cr), applying the normalized Cockcroft-Gault formula. (R) under bar(e) under bar(s) under bar(u) under bar(l) under bar(t) under bar(s) under bar: Overall, i-Mg, as well as t-Mg, showed a statistically significant negative logarithmic correlation with C-Cr (i-Mg: r = -0.75; t-Mg: r = -0.73) and i-Mg highly correlated with t-Mg (r = 0.94). Surprisingly, in mild renal failure (C-Cr > 80 ml/min/1.73 m(2)), i-Mg and t-Mg were in the low-normal to hypomagnesemic range (i-Mg <= 0.56 mmol/l, t-Mg: 0.85 mmol/l). In moderate renal failure (C-Cr < 30 and <= 80 ml/min/1.73 m(2)), I-Mg and t-Mg were usually in the reference interval (i-Mg: 0.49 - 0.63 mmol/l, t-Mg: 0.75 - 0.95 mmol/l). In severe renal failure (C-Cr < 30 ml/min/1.73 m(2)), i-Mg and t-Mg were in the high-normal to hypermagnesemic range (i-Mg >= 0.56 mmol/l, t-Mg >= 0.85 mmol/l). (C) under bar(o) under bar(n) under bar(c) under bar(l) under bar(u) under bar(s) under bar(i) under bar(o) under bar(n) under bar(s ) under bar: The measurement of i-Mg offered no advantage over the measurement of t-Mg. The observation of low Mg values in mild renal failure may have implications for the common treatment of chronic renal failure (CRF) patients with drugs that have a Mg-lowering side effect (diuretics, potassium-lowering agents).

Rapid Communications in Mass SpectrometryVolume 18, Issue 13 p. 1539-1540 Letter to the Editor Development of a simplified sample pretreatment procedure as part of an isotope dilution-liquid chromatography/tandem mass spectrometry candidate reference measurement procedure for serum total thyroxine Katleen Van Uytfanghe, Katleen Van Uytfanghe Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Gent, BelgiumSearch for more papers by this authorDietmar Stöckl, Dietmar Stöckl Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Gent, BelgiumSearch for more papers by this authorLinda M. Thienpont, Corresponding Author Linda M. Thienpont linda.thienpont@ugent.be Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Gent, BelgiumLaboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Gent, Belgium.Search for more papers by this author Katleen Van Uytfanghe, Katleen Van Uytfanghe Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Gent, BelgiumSearch for more papers by this authorDietmar Stöckl, Dietmar Stöckl Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Gent, BelgiumSearch for more papers by this authorLinda M. Thienpont, Corresponding Author Linda M. Thienpont linda.thienpont@ugent.be Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Gent, BelgiumLaboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Gent, Belgium.Search for more papers by this author First published: 11 June 2004 https://doi.org/10.1002/rcm.1510Citations: 16Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume18, Issue1315 July 2004Pages 1539-1540 RelatedInformation

BACKGROUND:To assess the analytical validity of free testosterone (FTe) measurements, a reference measurement procedure (RMP) is required. For steroids, isotope dilution-mass spectrometry is accepted as state-of-the-art technology. Because FTe is defined as the hormone fraction in serum water in equilibrium with the protein-bound fraction, the RMP should include a physical separation step. The use of equilibrium dialysis (ED) or ultrafiltration (UF) is advocated. Our objective was to develop such a candidate RMP.METHODS:We selected UF combined with isotope dilution-gas chromatography-mass spectrometry (ID-GC/MS) for direct measurement of Te in the ultrafiltrate. After optimization of the UF process, the complete procedure was validated by use of split-sample comparisons with indirect ED (iED) and symmetric dialysis (SyD).RESULTS:The candidate RMP gave maximum within-day, between-day, and total CVs of 3.0%, 3.1%, and 4.3%. The Deming regression equations for the respective method comparisons were: UF-ID-GC/MS = 0.98(iED) - 53 pmol/L (r = 0.94; S(y|x)= 42 pmol/L) and UF-ID-GC/MS = 0.92(SyD) + 21 pmol/L (r = 0.97; S(y|x)= 31 pmol/L).CONCLUSIONS:We achieved the objective of a state-of-the-art candidate RMP, which agreed well with iED and SyD. However, we also demonstrated that a degree of discordance remains, which may require a decision from an authoritative organization on the recommended procedure to measure free hormone concentrations.

Rapid Communications in Mass SpectrometryVolume 18, Issue 24 p. 3140-3141 Letter to the Editor Collision-induced dissociation of the [M2H]2− ion of C-peptide Dietmar Stöckl, Dietmar Stöckl Laboratorium voor Analytische Chemie, Faculteit Farmaceutische Wetenschappen, Universiteit Gent, Harelbekestraat 72, B-9000 Gent, BelgiumSearch for more papers by this authorDiego Rodríguez Cabaleiro, Diego Rodríguez Cabaleiro Laboratorium voor Analytische Chemie, Faculteit Farmaceutische Wetenschappen, Universiteit Gent, Harelbekestraat 72, B-9000 Gent, BelgiumSearch for more papers by this authorLinda M. Thienpont, Corresponding Author Linda M. Thienpont [email protected] Laboratorium voor Analytische Chemie, Faculteit Farmaceutische Wetenschappen, Universiteit Gent, Harelbekestraat 72, B-9000 Gent, BelgiumLaboratorium voor Analytische Chemie, Faculteit Farmaceutische Wetenschappen, Universiteit Gent, Harelbekestraat 72, B-9000 Gent, Belgium.Search for more papers by this author Dietmar Stöckl, Dietmar Stöckl Laboratorium voor Analytische Chemie, Faculteit Farmaceutische Wetenschappen, Universiteit Gent, Harelbekestraat 72, B-9000 Gent, BelgiumSearch for more papers by this authorDiego Rodríguez Cabaleiro, Diego Rodríguez Cabaleiro Laboratorium voor Analytische Chemie, Faculteit Farmaceutische Wetenschappen, Universiteit Gent, Harelbekestraat 72, B-9000 Gent, BelgiumSearch for more papers by this authorLinda M. Thienpont, Corresponding Author Linda M. Thienpont [email protected] Laboratorium voor Analytische Chemie, Faculteit Farmaceutische Wetenschappen, Universiteit Gent, Harelbekestraat 72, B-9000 Gent, BelgiumLaboratorium voor Analytische Chemie, Faculteit Farmaceutische Wetenschappen, Universiteit Gent, Harelbekestraat 72, B-9000 Gent, Belgium.Search for more papers by this author First published: 24 November 2004 https://doi.org/10.1002/rcm.1716Citations: 6Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. REFERENCES 1 Fierens C, Stöckl D, Baetens D, De Leenheer AP, Thienpont LM. J. Chromatogr. B 2003; 792: 249. 2 Fierens C, Thienpont LM, Stöckl D, De Leenheer AP. Anal. Biochem. 2000; 285: 168. 3 Biemann K, Martin SA. Mass Spectrom. Rev. 1987; 6: 1. 4 Bowie JH, Brinkworth CS, Dua S. Mass Spectrom. Rev. 2002, 21: 87. Citing Literature Volume18, Issue2430 December 2004Pages 3140-3141 ReferencesRelatedInformation

The Czech External Quality Assessment Scheme organized a survey using 14 fresh-frozen sera targeted for cholesterol and glucose by reference measurement procedures. The objective was to investigate whether it could fulfil a post-market vigilance function for in vitro diagnostic medical devices and assess trueness of participants' results. It revealed a mean bias of +5.1% for cholesterol and +3.7% for glucose (n approximately 150). However, the bias source (manufacturer or laboratory) could not be identified unequivocally because of the lack of homogeneous groups. This was due to the fact that laboratories mainly used reagents from manufacturers that do not market instruments or combined calibrators and reagents from different sources. Consequently, these habits did not allow the survey to fulfil the vigilance function. On the other hand, we were able to show the individual participants results for patient samples deviating from the true value (deviations >10% in approximately 20% of the laboratories). However, again, the survey failed in problem-solving via peer-group evaluation, even for participants that applied homogeneous tests. If other European schemes confirm this outcome, cooperation and/or participation of manufacturers may be the solution. The survey pointed out to the other participants, interchanging instrument, reagent and calibrator, that they are themselves responsible for the problems shown and hence also for problem-solving.

This study applied electrospray ionization-isotope dilution–liquid chromatography–tandem mass spectrometry for the evaluation of five urinary C-peptide immunoassays via split-sample measurements. The immunoassays measured in duplicate in the same run, the comparison method in triplicate over different runs. From the data, the within-run imprecision and the method comparison total RSDs were calculated. Regression analysis revealed on the one hand systematic differences, on the other, an excellent correlation between the test and comparison methods. From the spread of the data around the regression line in comparison with the 95% prediction intervals from the total RSD, sample-related effects and/or specificity problems were apparent and investigated.

The accurate antenatal prediction of fetal lung maturity (FLM) based on results from amniotic fluid samples is of

An external quality assessment (EQA) survey on 14 fresh‐frozen, single‐donation sera assigned with reference measurement procedure (RMP) values revealed a mean bias of +5.2% and +3.7% for the cholesterol oxidase and the photometric glucose oxidase procedure groups, respectively. Conversely, on lyophilized sera, the same procedure groups showed almost bias‐free results, the differences from the RMP values being only −0.8% for cholesterol and +0.7% for glucose. These data, which are in fairly good agreement with the literature, suggest the existence of artificial matrix effects in processed materials. Therefore they indicate that, currently, assessment of trueness is hampered in many European EQA schemes, as most of them use lyophilized sera. This approach may give a false impression about the trueness of laboratory results as well as carrying the risk that laboratories calibrated on the RMP values of the survey samples could make errors in patient testing. Consequently, if European EQA is willing to fulfil a post‐market vigilance function of the performance of in vitro diagnostic medical devices, then the time has come to tackle the problem of the quality of the survey samples. EQA organizers urgently need to make an effort to seek out materials that analytically behave like authentic clinical specimens. In the meantime, alternative approaches should be used. Although not ideal, the special survey described in this article is one of the possibilities. Naturally, it implies logistic problems and increased costs for the individual EQA schemes. However, both can be overcome with the cooperation of the predominantly nationally organized schemes.

AIM OF THE STUDY:Based on data in the literature, it remains unclear whether the ionized fraction of serum total magnesium (Mg) is lower in chronic hemodialysis (HD) patients compared to healthy subjects.PATIENTS AND METHODS:The ionized fraction of serum total Mg was investigated in 49 HD patients, pre- and post-dialysis, and compared to 30 healthy controls. The quality of the analytical performance of the Mg measurements has been emphasized by applying a reference method and/or rigorous internal quality control (IQC). In addition, the ionized fraction of serum total calcium (Ca) was measured in both populations, because the results for Mg should be related to those of Ca.RESULTS:In HD patients, the ionized fraction of serum total Mg was on average 65% (pre-dialysis 64.2% and post-dialysis 66.2%). In healthy controls, the ionized fraction was 64.9%. When the analytical variability was taken into account, no significant differences (p > 0.05) were observed between pre- and post-dialysis samples and controls. For Ca, an ionized fraction of 55.3% was found in HD patients, which was not significantly different from the fraction obtained in the control group (55.7%).CONCLUSION:The present study demonstrates that, compared to healthy controls, the ionized fraction of serum total Mg is not different in hemodialysis patients.

Using human insulin (MW 5808 Da) as a model compound, the possible strategies towards optimization of sensitivity and selectivity of measurement by electrospray ionization with a standard triple quadrupole mass spectrometer were investigated. For measurement in selected ion-monitoring (SIM) mode, these strategies involved systematic variation of instrumental parameters and spray pH. In this investigation four different operating modes were used corresponding to positive/negative ionization modes with acidic/basic sprays and pH reversed (hereafter termed 'wrong-way-round' operation); the cone voltage was optimized for each mode of operation. When collision-activated dissociation (CAD) is employed, two additional operation modes are possible: namely, low collision energies (10-35 eV, CAD-l) for the generation of sequence-specific fragments and high collision energies (>80 eV, CAD-h) for the generation of nonspecific fragments. Overall, this results in twelve different modes of operation. Loop-injection of aqueous insulin standards were run for each of the twelve operating modes and measurements made for five different charge states (n = 2-6) observable with our instrument that has an upper mass limit of m/z 4000. The signal/noise (S/N) ratio was optimized for each charge state, resulting in 60 measurements. The best S/N ratios (20 000) were achieved under positive SIM conditions with charge state 6 (m/z 969) and under 'wrong-way-round' negative SIM conditions with charge state 3 (m/z 1935). Lower S/N ratios were observed under positive CAD-h conditions with charge state 5 (m/z 1163, S/N 15 000) and positive CAD-l conditions with charge state 6 (m/z 969, S/N 10 000). All other operating modes gave maximum S/N ratios of 4000. For measurement of insulin standards, the results obtained show SIM to give the best S/N ratio. However, for samples in complex matrices, our general experience suggests CAD to be the preferable operating mode. Consequently, for the development of a quantitative method for proteins in general, it might be advocated that all of the twelve operating modes and all relevant charge states be investigated to find the optimum S/N ratio.

We describe the first results of a quantitative LC–tandem mass spectrometry method for urinary C-peptide with the use of [2H14]C-peptide as internal standard. LC was based on gradient elution of a Hypersil PEP C18 column. Mass spectrometry was performed in the negative electrospray ionization mode and by monitoring of the transitions at m/z 1514/1334 ([2H14]C-peptide) and 1507/1320 (C-peptide). For sample preparation, we applied ultrafiltration. The analytical performance of the method in terms of measurement precision gave an RSD of <2% (n=10). The overall imprecision was investigated from independent analysis of two urine samples in six-fold and resulted in an RSD<5%. The limit of detection, expressed as signal-to-noise ratio 3, was ∼0.15 ng C-peptide injected. Analysis of 10 random urine samples from laboratory volunteers showed interference-free ion chromatograms at a signal-to-noise ratio of ∼75 on average. The C-peptide concentrations calculated from quantification by the bracketing calibration technique ranged from 32 to 165 ng/ml.