UNASSIGNED: To assess the inter-laboratory comparability and intra-assay reproducibility of full blood count (FBC) results.
UNASSIGNED: Exploratory cross-sectional study.
UNASSIGNED: Three and two selected medical laboratories in the northern and southern zones, respectively.
UNASSIGNED: Forty-nine individuals per zone; 16 type 2 diabetes mellitus, 16 with HbAS haemoglobin type and 17 normal samples.
UNASSIGNED: Each sample was run eleven times through the analysers in the participating laboratories to evaluate intra-laboratory reproducibility and comparability of FBC results.
UNASSIGNED: Intra-laboratory reproducibility was evaluated using %coefficient variation (%CV). Interlaboratory comparisons were assessed through t-test or One-Way ANOVA for two-sample and three-sample tests. All statistical testing was undertaken using the two-tailed assumption.
UNASSIGNED: Statistically significantly different haemoglobin levels were estimated in both northern and southern zones (mean difference 0.00 g/dL to 3.75 g/dL vs 0.18 g/dL to 1.92 g/dL respectively). Also, total WBC counts significantly differed across laboratories in both northern and southern zones (mean difference 0.15 ×109/L - 3.86 ×109/L vs 0.02 ×109/L to 1.39 ×109/L respectively). Furthermore, platelet counts significantly differed across the participating laboratories in the northern and southern zones (mean difference 0.40 ×109/L to 299.76 ×109/L vs 5.7 ×109/L to 76.9 ×109/L respectively). Moreover, there was evidence of non-reproducibility of results within the respective laboratories in each zone as the respective %CV were outside the acceptable limits.
UNASSIGNED: The intra-laboratory non-reproducibility and inter-laboratory non-comparability of FBC results highlight the need to establish a national quality assessment scheme to harmonise laboratory practices nationwide.
UNASSIGNED: This study was funded by the University of Cape Coast Individual-Led Research Support Grant (RSG-INDI-CoHAS-2019-107).

UNASSIGNED: Since 2007, national public health laboratories in the WHO Eastern Mediterranean Region (EMR) have participated in a regional external quality assessment scheme in bacteriology to improve testing proficiency.
UNASSIGNED: To assess laboratory performance in bacteriology in the EMR between 2011 and 2019 using the regional external quality assessment scheme.
UNASSIGNED: We analysed the accuracy of participant-reported data in bacterial identification, Gram stain microscopy, and antimicrobial susceptibility testing. For each category, we assessed the performance over time, the performance on multiple organisms, and whether a laboratory repeatedly failed to attain satisfactory results.
UNASSIGNED: Between 2011 and 2019, 70% of laboratories achieved satisfactory performance for bacterial identification and antimicrobial susceptibility testing, and 85% performed satisfactory Gram stain microscopy. Testing did not improve on multiple organisms and results were consistently low for some pathogens and test categories. Twenty-nine percent of laboratories underperformed throughout the study period.
UNASSIGNED: The unchanged performance over time and underperformance of laboratories highlight the need for improvements in the regional external quality assessment scheme. Participating laboratories and WHO need to work more actively to strengthen the problem areas.
التقييم الخارجي لجودة أداء المختبرات المتخصصة في علم الجراثيم في إقليم شرق المتوسط، 2011–2019.
همايون أصغر، كارين نهابتيان، أماني غنيم، فرانك كونينجز، أمينة الجرداني.
UNASSIGNED: منذ عام 2007 ، شاركت مختبرات الصحة العامة الوطنية في إقليم شرق المتوسط في مخطط إقليمي للتقييم الخارجي للجودة في علم الجراثيم لتحسين كفاءة الاختبارات.
UNASSIGNED: هدفت هذه الدراسة الى تقييم أداء المختبرات في مجال علم الجراثيم في إقليم شرق المتوسط بين عامَي 2011 و 2019 ، باستخدام النظام الإقليمي للتقييم الخارجي للجودة.
UNASSIGNED: حللنا دقة البيانات التي أبلغ بها المشاركون فيما يخص تحديد الجراثيم، والفحص المجهري لصبغة جرام، واختبار الحساسية لمضادات الميكروبات. وبالنسبة إلى كل فئة، قيمنا الأداء مع مرور الزمن، والأداء على كائنات حية متعددة، وما إذا كان المختبر قد فشل مرارًا في تحقيق نتائج مُرضية.
UNASSIGNED: بين عامَي 2011 و 2019 ، حقق 70 ٪ من المختبرات أداءً مُرضيًا في التعرف على الجراثيم وتحديدها واختبار الحساسية لمضادات الميكروبات، ونفذ 85 ٪ منها الفحصَ المجهري لصبغة جرام تنفيذًا مُرضيًا. ولم يتحسن مستوى الاختبار على كائنات حية متعددة، وكانت النتائج منخفضة باستمرار فيما يخص بعض مسببات الأمراض وفئات الاختبارات. وكان أداء 29 ٪ من المختبرات دون المستوى خلال فترة الدراسة.
UNASSIGNED: إن عدم تغيُُّّر الأداء بمرور الوقت والأداء القاصر للمختبرات يبرزان الحاجة إلى إدخال تحسينات على الخطة الإقليمية للتقييم الخارجي للجودة. لذا، يتعيََّّن على المختبرات المشارِكة و المختبرات المشاركة ومنظمة الصحة العالمية بحاجة إلى العمل بشكل أكثر نشاطا لتقوية مناطق المشاكل.
Évaluation externe de la qualité des performances des laboratoires en bactériologie dans la Région de la Méditerranée orientale, 2011-2019.
UNASSIGNED: Depuis 2007, les laboratoires de santé publique nationaux de la Région OMS de la Méditerranée orientale ont participé à un système régional d\'évaluation externe de la qualité en bactériologie afin d\'améliorer la bonne exécution des analyses.
UNASSIGNED: Évaluer les performances des laboratoires en bactériologie dans la Région de la Méditerranée orientale entre 2011 et 2019 à l\'aide du système régional d\'évaluation externe de la qualité.
UNASSIGNED: Nous avons analysé l\'exactitude des données communiquées par les participants concernant l\'identification bactérienne, la microscopie après coloration de Gram et les tests de sensibilité aux antimicrobiens. Pour chaque catégorie, nous avons évalué la performance au fil du temps, la performance sur plusieurs micro-organismes et avons vérifié si un laboratoire n\'a pas obtenu des résultats satisfaisants à plusieurs reprises.
UNASSIGNED: Entre 2011 et 2019, 70 % des laboratoires ont obtenu des résultats satisfaisants pour l\'identification bactérienne et les tests de sensibilité aux antimicrobiens, et 85 % ont effectué une microscopie après coloration de Gram satisfaisante. Les tests ne se sont pas améliorés sur plusieurs micro-organismes et les résultats étaient systématiquement faibles pour certains agents pathogènes et certaines catégories de tests. Vingt-neuf pour cent des laboratoires ont eu des résultats insuffisants tout au long de la période d\'étude.
UNASSIGNED: Les performances inchangées au cours du temps et les résultats insuffisants des laboratoires soulignent la nécessité d\'améliorer le système régional d\'évaluation externe de la qualité. Les laboratoires participants et l\'OMS doivent collaborer plus activement pour renforcer les domaines qui posent problème.

BACKGROUND: Free light chain (FLC) measurements are important in diagnosing monoclonal gammopathies. As FLC are heterogeneous, different reagents and instruments for measuring FLC concentrations may give diverging results that affect assessment of patients with monoclonal gammopathies. Here we investigated agreement between different FLC methods using data from the Swedish external quality assurance (EQA) programme.
METHODS: The two main FLC assays, N Latex FLC (Siemens) and Serum Freelite (The Binding Site), using four nephelometric or turbidimetric instrument platforms, were compared. Results from 27 EQA rounds distributed to 11-16 Swedish hospital laboratories during 2015-2020 were investigated.
RESULTS: The kappa (κ) FLC measurements deviated significantly over time, but when only nephelometry was used, deviation from the mean was lower (median ranges: -5% to 13 %). The CV was significantly higher for the Freelite assay (mean CV = 8.7) than for the N latex assay (mean CV = 5.7) (p < 0.0001). The coefficient of determination between all combinations of reagents and instrument platforms used was generally good (r2 = 0.76-0.87), and the correlation slope acceptable (0.81-1.2). For lambda (λ) FLC measurements, no concordance between combinations of instruments and reagents is apparent, deviating between -40 % to + 48 % from the mean. The CV was significantly higher for the combination with nephelometry and the Freelite assay (CV mean = 13.9 %) than nephelometry and the N latex assay (CV mean = 9.9 %) (p <0.001). The coefficient of determination varied between combinations of reagents and instrument platforms (r2 = 0.59-0.89) and the slope ranged between 0.48 and 1.5. Significant differences between the two reagents used were sometimes noted.
CONCLUSIONS: Imprecision in λFLC affects the κFLC/λFLC ratio. This may be important in clinical assessment of patients, especially differentiating between monoclonal and polyclonal gammopathies.

During the last two years, a variety of assays for the serological detection of antibodies to the new SARS-CoV-2 virus have been launched and used as part of standard care in many laboratories. The pace with which these tests have been introduced into routine care emphasizes the importance of quality measures for analytical methods, particularly with regard to the implications of results for clinical and epidemiologic decisions. Accuracy, reliability and comparability of analytical test results are thus essential, and here external quality assessment (EQA) is the most important quality assurance tool. It allows us to achieve harmonization of test methods as a prerequisite for a high standard of performance for laboratory and analytical techniques and their interpretation.
This EQA scheme consisted of pre-characterized clinical biospecimens dedicated to the analysis of anti-SARS-CoV-2 IgG total antibodies and differentiation into spike protein-specific IgG antibodies against SARS-CoV-2 (anti-S-SARS-CoV-2) and nucleocapsid-specific IgG antibodies against SARS-CoV-2 (anti-N-SARS-CoV-2).
A total of 239 laboratories across Europe participated in this scheme, called CoVimm. In detail, 536 results for anti-SARS-CoV-2 IgG, 431 results for anti-S-SARS-CoV-2 IgG, and 200 results for anti-N-SARS-CoV-2 IgG were reported. Based on the pre-defined thresholds, the success rates for the determination of anti-S-SARS-CoV-2 IgG and anti-N-SARS-CoV-2 IgG were 96% and 90%, respectively. Interestingly, only 64% of the participating laboratories successfully passed the EQA scheme for the determination of total anti-SARS-CoV-2 IgG.
This EQA revealed serious concerns regarding the reliability and appropriate use of anti-SARS-CoV-2 antibody assays in routine care. In addition to the wide heterogeneity of different assays used by participating laboratories, a lack of standardization and harmonization is also evident. This is of particular importance for reliable and clinically meaningful interpretation of test results.

We report on sample IS/17575 since it generated highly divergent results in the Belgian SARS-CoV-2 serology external quality assessment scheme. Sample IS/17575 was serum originating from a 30 years old male patient. 124 diagnostic laboratories analysed this sample. A total of 168 results was returned (including 5 doubles). Overall, 38 were positive. All tests against S1 were positive except the Euroimmun IgG ELISA and the Ortho clinical Diagnostics VITROS IgG CLIA. All tests against S1/S2 (Liaison, Diasorin) resulted in a signal above cutoff. Assays against RBD, mostly generate a negative result. An exception are the Wantai SARS-CoV-2 ELISA\'s. All tests targeting N protein were negative. The survey shows, when >6 months post-infection, assays targeting at least S1, and preferably S1 combined with S2, are the most sensitive. This finding accentuates the necessity of external quality assessment schedules and importance of antigenic composition of serologic SARS-CoV-2 assays.

Numerous analytical systems, rapidly made available on the market throughout the SARS-CoV-2 pandemic, aim to detect COVID-19, and to continuously update and improve the same systems. Medical laboratory professionals have also developed in-house analytical procedures in order to satisfy the enormous volume of requests for tests. These developments have highlighted the need control the analytical procedures used in order to guarantee patient safety. The External Quality Assessment (EQA) Scheme, an important quality assurance tool, aims to guarantee high standard performance for laboratory and analytical procedures. The aim of the present study was to report on the results collected in an experimental EQA scheme for the serological diagnosis of SARS-CoV-2.
All qualitative results collected in the different EQA surveys were summarized in order to identify the percentage of laboratory results in relation to typology of antibodies, results and samples.
A total of 4,867 data sets were collected. The analysis of EQA data made, demonstrates a better agreement among laboratories results for total Ig than single immunoglobulins (IgG, IgM, IgA) in the case samples positive for SARS-CoV-2, and a wide divergence between IgM results for positive samples (only 34.9% were correct). Results for negative controls and specificity controls demonstrated a better overall agreement than results for positive samples.
Working in collaboration with the IVD manufacturers, laboratory professionals must strive to achieve harmonization of results, and to develop well-defined protocols complying with the ISO 15189 requirements.

External quality assessment (EQA) is a key instrument for achieving harmonization, and thus a high quality, of diagnostic procedures. As reliable test results are crucial for accurate assessment of SARS-CoV-2 infection prevalence, vaccine response, and immunity, and thus for successful management of the ongoing COVID-19 pandemic, the Reference Institute for Bioanalytics (RfB) was the first EQA provider to offer an open scheme for anti-SARS-CoV-2 antibody detection. The main objectives of this EQA were (i) to gain insights into the current diagnostic landscape and the performance of serological tests in Europe and (ii) to provide recommendations for diagnostic improvements. Within the EQA, a blinded panel of precharacterized human serum samples with variable anti-SARS-CoV-2 antibody titers was provided for detection of anti-SARS-CoV-2 IgG, IgA, and IgM antibodies. Across the three distribution rounds in 2020, 284 laboratories from 22 countries reported a total of 3,744 results for anti-SARS-CoV-2 antibody detection using more than 24 different assays for IgG. Overall, 97/3,004 results were false for anti-SARS-CoV-2 IgG, 88/248 for IgA, and 34/124 for IgM. Regarding diagnostic sensitivity and specificity, substantial differences were found between the different assays used, as well as between certified and noncertified tests. For cutoff samples, a drop in the diagnostic sensitivity to 46.3% and high interlaboratory variability were observed. In general, this EQA highlights the current variability of anti-SARS-CoV-2 antibody detection, technical limitations with respect to cutoff samples, and the lack of harmonization of testing procedures. Recommendations are provided to help laboratories and manufacturers further improve the quality of anti-SARS-CoV-2 serological diagnostics.

Objectives Assessment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection prevalence and immunity is cornerstones in the fight against COVID-19 pandemic. For pandemic control, reliable assays for the detection of anti-SARS-CoV-2 antibodies are required. This pilot external quality assessment (EQA) scheme aimed to independently assess the participants\' clinical performance of anti-SARS-CoV-2 testing, to identify shortcomings in clinical practice and to evaluate the suitability of the scheme format. Methods The EQA scheme consisted of eight serum samples with variable reactivity against SARS-CoV-2 intended for the analysis of anti-SARS-CoV-2 immunoglobulin (Ig)G, IgA, and IgM antibodies. Laboratories reported: (1) results for each sample and the respective method, (2) raw data from replicate testing of each sample. Results The 16 selected pilot EQA participants reported 294 interpreted results and 796 raw data results from replicate testing. The overall error rate for the anti-SARS-CoV-2 IgG, IgA, and IgM tests was 2.7, 6.9, and 16.7%, respectively. While the overall diagnostic specificity was rated as very high, sensitivity rates between 67 and 98% indicate considerable quality differences between the manufacturers, especially for IgA and IgM. Conclusions Even the results reported by the small number of participants indicate a very heterogeneous landscape of anti-SARS-CoV-2 serological testing. Differences of available tests and the individual performance of laboratories result in a success rate of 57.1% with one laboratory succeeding for all three antibody-classes. These results are an incentive for laboratories to participate in upcoming open EQA schemes that are needed to achieve a harmonization of test results and to improve serological testing.

BACKGROUND: External quality assessment schemes (EQAS) can provide important information regarding accuracy and comparability of different measurement methods if the sample matrices are composed of commutable material. The aim of this study was to assess the commutability of different matrices for the material used in an EQAS for amitriptyline and nortriptyline.
METHODS: Proficiency testing material (PTM) and patient samples containing amitriptyline and nortriptyline were prepared, collected, pooled, and distributed to participating laboratories for analysis. Low, medium and high concentrations of both drugs in liquid pooled human, lyophilized human and lyophilized bovine serum were tested in this study. The measurement deviation of the PTM results to the patient serum regression line were normalized by dividing trough the average within-laboratory SD (SDwl) derived from the results reported in the official EQAS, resulting in a relative residual. The commutability decision limit was set at 3 SDwl.
RESULTS: With 10 laboratories participating in this study, 45 laboratory couples were formed. All matrix types delivered several relative residuals outside the commutability decision limit. The number and the magnitude of relative residuals for both drugs were lower for liquid human sera as compared to lyophilized human and bovine sera.
CONCLUSIONS: The PTM used for amitriptyline and nortriptyline is preferably prepared with human serum, although not all relative residuals are within the commutability decision limit.

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.