External Quality Assessment (EQA) program for the preanalytical and analytical immunohistochemical determination of HER2 in breast cancer: an experience on a regional scale

ABSTRACT Accurate determination of diphtheria toxin antibodies is of value in determining the rates of immunity within broad populations or the immune status of individuals who may be at risk of infection, by assessing responses to vaccination and immunization schedule efficacy. Here we report the results of an external quality assessment (EQA) study for diphtheria serology, performed within the dedicated surveillance network DIPNET. Twelve national laboratories from 11 European countries participated by testing a standard panel of 150 sera using their current routine method: Vero cell neutralization test (NT), double-antigen enzyme-linked immunosorbent assay (ELISA; DAE), dual double-antigen time-resolved fluorescence immunoassay (dDA-DELFIA), passive hemagglutination assay (PHA), toxin binding inhibition assay (ToBI), and in-house or commercial ELISAs. The objective of the study was not to identify the best assay, as the advantages and drawbacks of methods used were known, but to verify if laboratories using their routine method would have categorized (as negative, equivocal, or positive) a serum sample in the same way. The performance of each laboratory was determined by comparing its results on a quantitative and qualitative basis to NT results from a single reference laboratory, as this test is considered the in vitro “gold standard.” The performance of laboratories using NT was generally very good, while the laboratories’ performance using other in vitro methods was variable. Laboratories using ELISA and PHA performed less well than those using DAE, dDA-DELFIA, or ToBI. EQA is important for both laboratories that use in vitro nonstandardized methods and those that use commercial ELISA kits.

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Determination of Aluminium in Serum: Findings of an External Quality Assessment Scheme

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456328502200403 ◽

1985 ◽

Vol 22 (4) ◽

pp. 351-358 ◽

Cited By ~ 13

Author(s):

A. Taylor ◽

B. J. Starkey ◽

A. W. Walker

Keyword(s):

Quality Assessment ◽

External Quality Assessment ◽

External Quality ◽

External Quality Assessment Scheme

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Reproducibility of mRNA-Based Testing of ESR1, PGR, ERBB2, and MKI67 Expression in Invasive Breast Cancer—A Europe-Wide External Quality Assessment

Cancers ◽

10.3390/cancers13184718 ◽

2021 ◽

Vol 13 (18) ◽

pp. 4718

Author(s):

Ramona Erber ◽

Arndt Hartmann ◽

Peter Andreas Fasching ◽

Matthias Ruebner ◽

Robert Stöhr ◽

...

Keyword(s):

Breast Cancer ◽

Quality Assessment ◽

Invasive Breast Cancer ◽

External Quality Assessment ◽

External Quality ◽

Ki 67 ◽

Erbb2 Mrna ◽

Reproducible Method ◽

Sensitivity Specificity

Estrogen receptor (ER), progesterone receptor (PgR), Ki-67, and HER2 immunohistochemistry (IHC) together with HER2 in situ hybridization (ISH) are utilized to classify invasive breast cancer (IBC) into predictive molecular subtypes. As IHC evaluation may be hampered by analytical errors, gene expression assays could offer a reliable alternative. In this first Europe-wide external quality assessment (EQA) study, we investigated performance of mRNA-based Xpert® Breast Cancer STRAT4 (CE-IVD) in five European laboratories. The cohort comprised ten pre-therapy IBC core biopsies diagnosed in the coordinating center (CC). STRAT4 binary (positive or negative) mRNA results of each marker (ESR1, PGR, ERBB2, MKI67) were compared with the gold standard IHC/ISH performed by the CC. Sensitivity, specificity, and accuracy of ESR1 and ERBB2 mRNA were 100% for all samples. In contrast, PGR expression was falsely negative for one case by two sites and MKI67 falsely negative for two cases (respectively by four and one sites). These cases had STRAT4 expression values close to assay cut-offs and immunohistochemically presented heterogeneous low positive PgR and heterogeneous Ki-67. Our EQA shows that STRAT4 mRNA assay may be a reproducible method to evaluate ER, PgR, HER2, and Ki-67 status. However, cases with expression values close to assay cut-offs should be carefully reviewed.

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Accuracy of determination of the glomerular filtration marker iohexol by European laboratories as monitored by external quality assessment

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2018-1175 ◽

2019 ◽

Vol 57 (7) ◽

pp. 1006-1011 ◽

Cited By ~ 1

Author(s):

Gunnar Nordin ◽

Sara Ekvall ◽

Carolina Kristoffersson ◽

Ann-Sofie Jonsson ◽

Sten-Erik Bäck ◽

...

Keyword(s):

Glomerular Filtration Rate ◽

Quality Assessment ◽

Glomerular Filtration ◽

Filtration Rate ◽

External Quality Assessment ◽

Plasma Samples ◽

High Quality ◽

External Quality ◽

The Mean

Abstract Background Glomerular filtration is the most important kidney function. The most accurate glomerular filtration rate (GFR) estimates are based on the clearance of exogenous filtration markers. Of these, iohexol is the only exogenous marker that is included in an external quality assessment (EQA) scheme. The aim of the present study was to evaluate the performance of the European laboratories participating in Equalis’ EQA scheme for iohexol. Methods Weighed amounts of iohexol (Omnipaque) were added to plasma samples and distributed to laboratories participating in the EQA scheme for iohexol. All laboratories performed the assays in a blinded fashion. Results The number of participating laboratories varied between 27 and 34 during the study period. Iohexol was determined by HPLC in 77% of the laboratories and by UPLC/MS/MS methods in 15% of the laboratories. The mean interlaboratory coefficient of variation was 4.7% for the HPLC methods and 6.4% for the UPLC/MS/MS methods. The mean bias between calculated and measured iohexol values was –1.3 mg/L (95% confidence interval ±0.3) during the first part of the study period and 0.1 mg/L (±0.3) during the later part. Conclusions The low interlaboratory variation demonstrates that iohexol can be measured reliably by many laboratories and supports the use of iohexol as a GFR marker when there is a need for high quality GFR measurements.

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The Polish National External Quality Assessment Scheme in Microbiological Diagnostics – POLMICRO 2017

Diagnostyka Laboratoryjna ◽

10.5604/01.3001.0013.7709 ◽

2018 ◽

Vol 54 (3) ◽

pp. 159-166 ◽

Cited By ~ 1

Author(s):

Ewa Młodzińska ◽

Karolina Bosacka ◽

Anna Mikołajczyk ◽

Joanna Rybicka ◽

Elżbieta Stefaniuk ◽

...

Keyword(s):

Quality Control ◽

Quality Assessment ◽

External Quality Assessment ◽

Resistance Mechanisms ◽

Bacterial Isolates ◽

External Quality ◽

External Quality Assessment Scheme ◽

Microbiological Diagnostics ◽

Antibiotics Detection

The Polish National External Quality Assessment Scheme in Microbiological Diagnostics – POLMICRO programme is organized by the Centre of Quality Control in Microbiology (CQCM). The aim of the POLMICRO 2017 Programme was to evaluate proficiency of laboratories in the identification of microorganisms, determination of susceptibility to antibiotics, detection of resistance mechanisms and interpretation of Gram slides. Bacterial isolates distributed within the Programme differed in their susceptibility to antibiotics and presence of various resistance mechanisms. The paper presents the results of the XXIV edition – POLMICRO 2017.

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The assessment of microbiological diagnostics’ credibility in Poland on the basis of the POLMICRO 2018 Programme results

Diagnostyka Laboratoryjna ◽

10.5604/01.3001.0013.7443 ◽

2020 ◽

Vol 55 (2) ◽

pp. 99-106 ◽

Cited By ~ 1

Author(s):

Ewa Młodzińska ◽

Karolina Bosacka ◽

Anna Mikołajczyk ◽

Joanna Rybicka ◽

Waleria Hryniewicz

Keyword(s):

Quality Control ◽

Quality Assessment ◽

External Quality Assessment ◽

Resistance Mechanisms ◽

Bacterial Isolates ◽

External Quality ◽

External Quality Assessment Scheme ◽

Microbiological Diagnostics ◽

Antibiotics Detection

POLMICRO programme – the Polish National External Quality Assessment Scheme in Microbiology is organized by the Centre of Quality Control in Microbiology (CQCM). The aim of the POLMICRO 2018 Programme was to evaluate proficiency of laboratories in the interpretation of Gram slides, identification of microorganisms, determination of susceptibility to antibiotics, detection of resistance mechanisms like ESBL, MBL, KPC, PRP or resistance of staphylococci to methicillin. Bacterial isolates distributed within the Programme differed in their susceptibility to antibiotics and the presence of various resistance mechanisms. The paper presents the results of the XXV edition – POLMICRO 2018.

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Quality Specifications for the Determination of Copper, Zinc, and Selenium in Human Serum or Plasma: Evaluation of an Approach Based on Biological and Analytical Variation

Clinical Chemistry ◽

10.1373/clinchem.2008.108142 ◽

2008 ◽

Vol 54 (11) ◽

pp. 1892-1899 ◽

Cited By ~ 26

Author(s):

Josiane Arnaud ◽

Jean-Philippe Weber ◽

Cas W Weykamp ◽

Patrick J Parsons ◽

Jurgen Angerer ◽

...

Keyword(s):

Quality Assessment ◽

Trace Element ◽

Interindividual Variability ◽

External Quality Assessment ◽

Serum Copper ◽

External Quality ◽

Target Concentration ◽

Quality Specifications ◽

Copper Zinc

Abstract Background: Trace element external quality assessment schemes monitor laboratory performance and provide a stimulus for improvement in accuracy. However, monitoring of participant performance varies according to the scheme and can lead to conflicting conclusions. Methods: Quality specifications based on biological intra- and interindividual variability were calculated and compared to those currently used by various trace element external quality assessment schemes for plasma or serum copper, zinc, and selenium concentrations. For this purpose, we evaluated results reported by participating laboratories in different schemes, at key concentrations, using z scores. Results: Minimal quality specifications developed from the biological intra- and interindividual variability were, for Cu, ±0.84 μmol/L or 12% of the assigned target concentration, whichever is greater; for Zn, ±1.20 μmol/L or 15% of the assigned target concentration, whichever is greater; and for Se, ±0.072 μmol/L or 12% of the assigned target concentration, whichever is greater. Reported performance of the participating laboratories depended on analyte, concentration, and the selected quality specification. In addition, the most commonly used methods for the determination of Cu, Zn, and Se may give different results. Conclusions: The proposed minimal quality specifications based on biological variation are generally slightly less stringent than those currently in use, although they do not drastically change the performance evaluation in the different schemes. These specifications are a first step in the harmonization of practices among the schemes and remain to be evaluated.

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Mass-spectrometric determination of serum cortisol: comparison of data from two independent laboratories.

Clinical Chemistry ◽

10.1093/clinchem/32.3.536 ◽

1986 ◽

Vol 32 (3) ◽

pp. 536-538 ◽

Cited By ~ 11

Author(s):

S J Gaskell ◽

L Sieckmann

Keyword(s):

Mass Spectrometry ◽

Quality Assessment ◽

Isotope Dilution ◽

External Quality Assessment ◽

Serum Cortisol ◽

Mass Spectrometric ◽

External Quality ◽

Mass Spectrometric Determination

Abstract Isotope dilution and mass spectrometry were used in two independent laboratories to determine cortisol in 15 plasma and serum pools used in the British and German national schemes for the external quality assessment of routine assays. For the concentration range 240-700 nmol/L, differences between the data obtained by the two laboratories were generally less than 4% but were approximately 7% in two instances. The discrepancies are nevertheless small in comparison with the bias observed for many routine assays.

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External quality assessment (EQA) program for the immunohistochemical detection of ER, PR and Ki-67 in breast cancer: results of an interlaboratory reproducibility ring study in China

BMC Cancer ◽

10.1186/s12885-019-6210-3 ◽

2019 ◽

Vol 19 (1) ◽

Author(s):

Tianjie Pu ◽

◽

Ruohong Shui ◽

Jie Shi ◽

Zhiyong Liang ◽

...

Keyword(s):

Breast Cancer ◽

Quality Assessment ◽

External Quality Assessment ◽

Reference Value ◽

Evaluation Process ◽

Daily Practice ◽

External Quality ◽

Ki 67 ◽

Perfect Agreement ◽

Misclassification Rates

Abstract Background An External Quality Assessment (EQA) program was developed to investigate the status of estrogen receptor (ER), progesterone receptor (PR), and Ki-67 immunohistochemical (IHC) detection in breast cancer and to evaluate the reproducibility of staining and interpretation in 44 pathology laboratories in China. Methods This program was implemented through three specific steps. In study I, three revising centres defined the reference value for 11 sections. In study II, 41 participating centres (PC) stained and interpreted 11 sections by their own daily practice IHC protocols. In study III, all cases received second interpretation opinions. Results The stained slides of 44 laboratories were up to the interpretation standard. The overall interpretation concordance rate of this study was over 90%. A perfect agreement was reached among the PCs for the cases with ER+ and PR+ > 50% and Ki-67 > 30%, whereas a moderate agreement was observed for intermediate categories. After second interpretations, the misclassification rates for ER were reduced by 12.20%, for PR were reduced by 17.07%, and for Ki-67 were reduced by 4.88%. Up to 31 PCs observed a benefit from the second opinion strategy. Conclusions This project is the first EQA study performed on a national scale for assessment of ER, PR and Ki-67 status by IHC in China. In the whole IHC evaluation process, the intermediate categories were less reproducible than those with high expression rates. Second opinions can significantly improve the diagnostic agreement of pathologists’ interpretations.

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