Interlaboratory Comparison Program Research Articles

Quality assurance of SARS-CoV-2 testing laboratories during the pandemic period in India – An experience from a designated provider laboratory

PurposeIndian Council of Medical Research (ICMR) initiated an Inter-Laboratory Quality Control testing (ILQC) program for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) testing. Under this program, SARS-CoV-2 testing laboratories across the country submit specimens to the assigned State Quality Control (SQCs) laboratories for ILQC testing. This study aimed to investigate the performance of public and private SARS-CoV-2 testing laboratories in Delhi and highlights the country’s effort in ramping up testing facility with close monitoring of the quality of Covid-19 testing results. MethodsIn the present study, two-years of SARS-CoV-2 testing data is included. During July 2020 through February 2022, a total of 1791 anonymised specimens were received from 56 public and private laboratories. These specimens were processed by reverse transcriptase – polymerase chain reaction (RT-PCR) tests as per National Institute of Virology (NIV) protocol and the results were uploaded on the ICMR quality control/quality assurance (QC/QA) portal without directly conveying the results to respective participating laboratories. This portal generated a final report stating concordance and intimate results to individual laboratories. ResultsAmong the 1791 specimens, 25 were rejected and the remaining 1766 were tested. Among these specimens 1691 (95.75%) revealed concordance, and 75 (4.24%) were discordant. A total of 29 laboratories had 100% concordance, 21 laboratories had over 90% concordance and six laboratories had over 80% concordance. ConclusionsThe study demonstrates that the establishment of an inter-laboratory comparison program for SARS-CoV-2 testing helped in monitoring quality of SARS-CoV-2 testing in the country.

The Implementation of Nongynecologic Reporting Systems in Cytopathology Laboratories Is Highly Variable: Analysis of Data From a 2020 Supplemental Survey of Participants in the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytology.

In recent years, several reporting systems have been developed by national and international cytopathology organizations to standardize the evaluation of specific cytopathology specimen types. To assess the current implementation rates, implementation methods, and barriers to implementation of commonly used nongynecologic reporting systems in cytopathology laboratories. Data were analyzed from a survey developed by the College of American Pathologists Cytopathology Committee and distributed to participants in the College of American Pathologists Nongynecologic Cytopathology Education Program mailing. Nongynecologic reporting systems with the highest rate of adoption were the Bethesda System for Reporting Thyroid Cytopathology, 2nd edition (74.1%; 552 of 745); the Paris System for Reporting Urinary Cytology (53.9%; 397 of 736); and the Milan System for Reporting Salivary Gland Cytopathology (29.1%; 200 of 688). The most common reason given for not adopting a reporting system was satisfaction with a laboratory's current system. Implementation varied among laboratories with regard to which stakeholders were involved in deciding to implement a system and the amount of education provided during the implementation process. The implementation of nongynecologic reporting systems in cytopathology laboratories was highly variable.

Rare PNH Cells May be Considered As Genuine PNH Clone: Insights from Analysis of the 5-Year French Nation-Wide Multicenter Observational Study

Introduction The successive International Guidelines (Borowitz. et al. Cytometry B Clin Cytom 2010; Illingworth. et al. Cytometry B Clin Cytom 2018) recommend both detection and follow-up of rare PNH cells using high-resolution flow cytometry (FCM) analysis. These rare PNH cells, defined as GPI-deficient cells ranging from 0.01% to <0.1%, are distinguished from minor PNH clone, ranging from 0.1% to 1%. However, clinical relevance as well as long-term evolution of such rare PNH cells are still unknown. Objective We aimed to compare clinical and biological presentation of patients with rare PNH cells or a minor PNH clone along with long-term follow-up using data provided by the 5-year French nation-wide multicenter observational study, the Observatory of PNH Clones. Methods All patients of any age with a newly or previously diagnosed PNH clone or GPI-deficient cells ≥0.01%, detected in France by FCM from February 29th, 2016 to February 28th, 2021 were eligible for inclusion in this Observatory, provided that the center had participated in the inter-laboratory comparison program ongoing since 2013 (Debliquis et. al. Am J Clin Pathol 2015). For each patient, the baseline assessment was always considered as the initial PNH clone detection, even if it occurred before the initiation of the Observatory. Thus, this strategy allowed the collection of cases with long-term follow-up. A referent cytometrist at each center included patients in the e-CRF available on the CytHem-HPN website providing clinical and biological information as well as FCM raw data files. This study was approved by the national research ethics board. Results As of February 28th, 2021, 41 registered flow cytometry laboratories across France enrolled 637 patients with a PNH clone or GPI-deficient cells ≥ 0.01%. Selection of patients displaying rare PNH cells (i.e., o.o1% to <0.1%) or a minor PNH clone (i.e., 0.1% to 1%) on neutrophils led to the re-examination of 163 patient FCM files (provided by 26 centers) by the two principal investigators. FCM data and the e-CRF filling were both thoroughly reviewed leading to the update of roughly half of the submitted files. This enabled the validation of 138 patients at diagnosis and the exclusion of 18 (11%) patients who did not display a genuine PNH clone according to the international recommendations (at least 20 clustered events). For 7 of 163 selected patients, exchanges with centers are still ongoing for FCM data validation or due to missing clinical or biological data. Sixty-nine of the 138 validated patients displayed at least one follow-up point (Figure 1). Thus, we were able to compare 49 patients with rare PNH cells and 89 patients with a minor PNH clone with a significantly different clone size on the 3 lineages (median size on neutrophils: 0.03 [0.01 - 0.09] vs 0.34 [0.1 - 0.97] ; p<0.0001, on monocytes: 0.03 [0 - 7.88 ] vs 0.50 [0 - 7.08] ; p<0.0001, on red blood cells: 0.01 [0 - 1.36 ] vs 0.08 [0 - 1.24]; p= 0.0096). The patient median age at diagnosis was similar for both groups, 59 years [6 - 91] with 4 pediatric cases (<18y) for "rare PNH cells” group vs 49 years [10 - 87] with 9 pediatric cases for "minor PNH clone” group and a M/F sex ratio of 1.45 vs 0.98. Diagnoses were made between 2010 and 2021 with clinical information available in 98% of cases (n=47 and 88). Ninety-two to 94% of patients from both groups displayed BM failure including mainly aplastic anemia (n=30/47 vs 61/88), myelodysplastic syndrome (n=2 vs 6) and unexplained cytopenia(s) (n=11 vs 16). Only 4 cases of thrombosis for "rare PNH cells” group vs 3 for "minor PNH clone” group were observed, and the 2 cases of hemolytic anemia belong to the latter group. A more severe thrombopenia was observed in the "minor PNH clone” (68 [2-356] vs 44 [2-308] G/l) while all other biological parameters showed no significant difference. Long-term follow-up up to 7.0 years showed that one third of patients from both groups displayed an increase in clone size (above 0.1% for "rare PNH cells” and above 1% for "minor PNH clone", see Figure 2), most remained stable and a few decreased, the disappearance being always due to BM transplantation. Conclusion This multicenter study based on robust FCM analysis showed no differences between the clinical and biological presentation of patients with either rare PNH cells or a minor PNH clone. Long-term follow-up showed that rare PNH cells can evolve into minor PNH clone, suggesting that these cases may be considered as genuine minor clones. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

First step in development and evaluation simultaneous determination of mycotoxins in cereals by liquid chromatography - mass spectrometry

Currently, solid phase extraction (SPE) with immunoaffinity columns is applied in&amp;nbsp;most standardized methods for mycotoxin determination to purify extracts and analysis by&amp;nbsp;HPLC-FLD, HPLC-UV/VIS or LC-MS/MS. Therefore, sample preparation and analysis by&amp;nbsp;instruments are time-consuming and high operating costs. The novel method allow&amp;nbsp;simultaneously identify nine mycotoxin compounds with selective, stable and accurate&amp;nbsp;results. The new method has been evaluated through three stages including validation as&amp;nbsp;requirements of CEN/TR 16059:2010 (phase 1), comparison with current standard methods&amp;nbsp;(phase 2), evaluate the method using an interlaboratory comparison program (phase 3). Cereal samples were extracted by QuEChERS and analyzed by LC-MS/MS. The limit&amp;nbsp;of quantitation (LOQ) was 0,5 &amp;mu;g/kg for each aflatoxin compound and 40 &amp;mu;g/kg, 25 &amp;mu;g/kg,&amp;nbsp;1 &amp;mu;g/kg, 75 &amp;mu;g/kg for&amp;nbsp;deoxynivalenol, zearalenone, ochratoxin A, each toxin fumonisin (B1&amp;amp;B2), respectively. The recovery is in the range of 70-120%, relative standard deviation&amp;nbsp;RSD &amp;lt; 20%. The novel method also gives the same results compared to the individual&amp;nbsp;standardized methods, using the immunoaffinity column in the extraction stage. At the&amp;nbsp;present, the method is being evaluated through an interlaboratory comparison program with&amp;nbsp;two rounds: round 1 (for survey) and round 2 (official round), which is expected to be&amp;nbsp;implemented in 2022. &amp;nbsp;

FOCUS4 biomarker laboratories: from the benefits to the practical and logistical issues faced during 6 years of centralised testing

AimsFOCUS4 was a phase II/III umbrella trial, recruiting patients with advanced or metastatic colorectal cancer, between 2014 and 2020. Molecular profiling of patients’ formalin-fixed, paraffin-embedded tumour blocks was undertaken at...

Capacity Building Efforts for Rabies Diagnosis in Resource-Limited Countries in Sub-Saharan Africa: A Case Report of the Central Veterinary Laboratory in Benin (Parakou).

Rabies has been listed as a priority zoonotic disease in many African countries and the countdown to reach the goal of eliminating dog-mediated human rabies deaths by 2030 means that disease control measures need to be applied fast. In this context, an essential pillar of any national plan to control rabies is the implementation of reliable diagnostic techniques to ensure the success of field surveillance systems. Although many African countries have received international support for the control of rabies–some countries, like Benin, have not received a similar level of support. Indeed, until 2018, Benin was not able to diagnose rabies and rabies diagnosis in animals as well as humans relied solely on observed clinical symptoms. Although the Central Veterinary Laboratory (CVL) of Parakou had the equipment to implement two recommended tests, the lack of specific reagents and skills prevented the implementation of a rabies diagnostic service. Here we present the joint efforts of the national authorities in Benin, intergovernmental agencies, and non-governmental organizations to assess the strengths and weaknesses of the government's rabies control efforts. We have applied the Stepwise Approach toward Rabies Elimination (SARE) analysis, implemented rabies diagnostic capacities at the CVL of Parakou, characterized strains of rabies virus circulating in Benin, and finally integrated an inter-laboratory comparison program.

Importance of Performance Improvement for Inter Laboratory Comparison (ILC) of Radiated Emission Measurements

The key factors that influence the Radiated Emission (RE) measurement results of Inter Laboratory Comparison (ILC) program, conducted as part of proficiency testing/Quality Assurance of EMC test laboratory are presented in this paper. The evaluated classical Z score results and overall performance of the participant EMC test laboratories in ILC program are affected by these factors. The performance improvement techniques to address the influencing factors and eliminate the deviation in test results of ILC program are outlined in detail. A case study was conducted in the frequency range from 30 MHz to 1 GHz, as the deviation in Z score results is predominant below 1 GHz. The importance of awareness required to conduct ILC program accurately with minimum possible errors is highlighted in this paper.

Practical Papers, Articles and Application Notes

Inter Laboratory Comparison (ILC) forms an integral part of an EMC test laboratory competence level. It provides objective evidence for accreditation purposes as well as demonstrates the comparability and acceptability of the test results measured in the accredited laboratory. The first paper, “Importance of Performance Improvement for Inter Laboratory Comparison (ILC) of Radiated Emission Measurements,” reveals that the test conditions and methodologies of the laboratories cannot be totally identical when testing a sample based on ILC. This can cause deviation in radiated emission (RE) measurement results, in addition to those described sources of uncertainty in the standards. Based on the test results obtained from 16 EMC test laboratories participating in the ILC program, the factors influencing the ILC program, performance improvement techniques, and corrective measures are discussed.

Assessment of the possibility of using the measurement of open time to assess and verify the constancy of performance of cementitious ceramic tile adhesives

The study analyzed the results of open time measurements of ceramic tile adhesives after not less than 30 minutes, obtained by 27 laboratories participating in the interlaboratory comparison program. The obtained results were statistically analyzed following the requirements of ISO 13528 and assessed under the z-score analysis criteria contained in the EN ISO/IEC 17043. 22 out of 24 laboratories that sent the results of the open time measurement confirmed their competencies, obtaining a “satisfactory” result following the evaluation criteria. The result obtained by one laboratory was classified as “questionable”, and another received the result as “unsatisfactory”. From the perspective of laboratories participating in interlaboratory comparisons, the obtained results should be assessed as satisfactory, and thus the laboratories confirm their competence. However, a wide scatter of the results of the open time measurement should be noted – 22 laboratories, the results of which were classified as “satisfactory”, obtained results from 0.1 N/mm2 to 1.0 N/mm2. Such a wide scatter of the results of open time measurements determined by the adhesion strength indicates that this method has too little accuracy, and it should not be used in the assessment and verification of constancy of performance of ceramic tile adhesives.

Inter-laboratory Comparisons and Their Roles in Accreditation

Results of interlaboratory comparisons and proficiency tests are a significant parameter for the calibration and testing laboratories for assuring the quality of test and calibration results performed by those laboratories. If test and calibration laboratories want to demonstrate that they operate according to a management system, that they are technically competent and that they can produce technically valid results in the tests and calibrations they perform for their customers, the general requirements they must meet are defined in ISO/IEC 17025:2017. This international standard forms the basis of international laboratory accreditation. Clause 7.7 Ensuring the validity of results in this standard requires laboratories to establish the procedures and instructions and other technical documentation needed to ensure the results of the tests and calibrations they perform. Participation in inter-laboratory comparison or proficiency testing programs is one of the most important of these activities. Participation in inter-laboratory comparisons provides an opportunity for laboratories to independently evaluate their analytical performance, both in absolute terms and in comparison, to other techniques. In this study, information about calibration laboratories and accreditation activities is given and the importance of inter-laboratory comparison studies is explained to ensure the results of the measurements made by calibration laboratories.

Determination of trace elements in urine by inductively coupled plasma-tandem mass spectrometry – Biomonitoring of adults in the German capital region

A method was developed and validated for multi-element analyses of human urine samples using inductively coupled plasma-tandem mass spectrometry. The combination of a simple sample preparation and the state-of-the-art technique allows high-throughput and lowest limits of quantification up to 1 ng/L. Thereby coefficients of variation ranges from 0.4% (V) to 3.7% (Be), and 0.9% (Cd) to 4.8% (Ni) for intraday and interday precision, respectively. The method's performance is demonstrated by successful participation in international interlaboratory comparison programs as external quality assurance.Moreover, the method was applied for the analysis of first-morning void urine samples of adults (N = 77) living in the German capital region. 15 metals and metalloids (Astotal, Be, Bi, Cd, Co, Cr, In, Mn, Mo, Ni, Pb, Sn, Tl, V, and Zn) were determined. With exception of indium, all elements were found in urine samples above the limit of quantification, demonstrating the suitability to measure the general population's exposure to these metals and metalloids. The method presented here shall be used for analysis of urine samples collected in the upcoming German Environmental Survey, GerES VI, a cross-sectional, population-representative study.

First Interim Analysis of the French National Observatory of Paroxysmal Nocturnal Hemoglobinuria Clones

Introduction: Following the published International Guidelines (Borowitz, 2010), the French-Belgian biological workshop was initiated in 2010 by the French Paroxysmal Nocturnal Hemoglobinuria (PNH) group (named HPNAFC). This effort to harmonize the diagnostic practices has been pursued through the development of an inter-laboratory comparison program, involving more than 50 French-speaking centers since 2013 (Debliquis, 2015). Thus, the French National Observatory of PNH clones opened for 5 years on the 9th International Rare Disease Day (February 29th 2016), in order to collect all PNH clone cases diagnosed by French cytometrists.Methods: The primary objective of the French National Observatory of PNH clones is to monitor all PNH clones ≥0.01%, along with two secondary objectives according to the PNH clone size: the evolution of minor clones <1% and the proportion and significance of type II and type III cells for clones ≥1%. All patients with a PNH clone ≥0.01% can be included, irrespective of age, provided that the center has validated a PNH flow cytometry quality control. For each patient, the inclusion time point always corresponds with the initial diagnosis date of the PNH clone, even if it was made before the opening of the Observatory, allowing the collection of all cases in the active French PNH file. This Observatory is based on a principle of non-opposition; inclusions are made by the referent cytometrist of each participating center by filling in the e-CRF form available on the HPNAFC website.Results: As of June 30th 2017, 39 cytometry laboratories have registered across France. Of these, 24 centers have submitted 163 inclusion points with a PNH clone above 0.01%, each corresponding to a patient. The cases were reviewed by the 2 principal investigators, who carefully re-examined all of the flow cytometry data. This method enabled the validation and inclusion of 126 cases, with 37 ongoing ones due to missing clinical or biological data. The first extraction led to the preliminary analysis of these 126 cases and showed that patient median age at diagnosis was 45 years [11-87], with 6 pediatric cases, and a M:F sex ratio of 0.83. Diagnosis was made between 1988 and 2017 and clinical information at diagnosis was available for 92% of patients. More than half of them had aplastic anemia (58.7%). Other diagnosis included: hemolytic anemia (with or without aplastic anemia) (15.9%), unexplained cytopenia(s)(7.9%), myelodysplastic syndrome (6.3%), hemoglobinuria (4.8%) and 2 cases (1.6%) of recurrent thrombosis without hemolysis. Biological data showed a median hemoglobin value of 9.3 g/dL [4.7-16.5], 1.4 x109/L [0.1-11] neutrophils and 60 x109/L [2-356] platelets. The median clone size at diagnosis was 1.9% on granulocytes with a very wide range from 0.01% to 99.4%, most of them being less than 10% and mainly composed of type III cells (median type III clone size: 1.6%). A similar distribution of PNH clones was observed on monocytes, with a good correlation between clone sizes on both lineages. RBC analysis, which was performed for less than half of the patients showed a majority of minor clones and no correlation was observed between PNH clone size on granulocytes and RBC, due to an underestimation of the clone size on RBC. Regarding the clinical context, the median PNH clone size on granulocytes in case of aplastic anemia was 1%, yet some patients had very large clones, higher than 99%. Conversely, PNH clones from patients with hemolytic anemia were very large with a median size of 88%, but some patients had smaller clones of less than 20%. The 2 patients with thrombosis displayed a much smaller clone size, below 0.05%.Conclusion: More than one year after its initiation, 126 confirmed patients were enrolled in the French National Observatory of PNH clones. Median PNH clone size was 1.9% on granulocytes and more than half of these patients had aplastic anemia. A good correlation was seen between clone sizes on granulocytes and monocytes, but not on granulocytes and RBCs. This collaborative work has established a strong network of motivated cytometrists as highlighted by the number of registered centers and the increasing inclusions since its recent opening. A comprehensive follow-up of a foreseeable larger number of PNH clones (so far 92 out of the 163 already have at least 1 follow up point) will lead to a better understanding of the physiopathology of minor PNH clones. DisclosuresDrenou:Alexion: Consultancy, Honoraria. Pruvot Debliquis:Alexion: Consultancy, Honoraria. Letestu:Alexion: Consultancy, Honoraria. Chatelain:Alexion: Consultancy, Honoraria. Socié:Alexion Pharmaceuticals, Inc.: Consultancy. Peffault De Latour:Pfizer: Consultancy, Honoraria, Research Funding; Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Amgen: Research Funding. Wagner Ballon:Alexion: Consultancy, Honoraria.

Interlaboratory Comparative Tests in Ready-Mixed Concrete Quality Assessment.

Proper quality assessment of ready-mixed concrete, which is currently the principal material for construction, land engineering and architecture, has an impact on the optimisation and verification of correct functioning of individual stages of the production process. According to the European Standard EN 206 “Concrete–Specification, performance, production and conformity”, obligatory conformity control of concrete is carried out by the producer during its production. In order to verify the quality of concrete, investors generally commission independent laboratory units to perform quality assessment of both concrete mix and hardened concrete, which guarantees a high quality of construction works. One of the essential tools for ensuring the quality of test results is the participation of laboratories in the so-called proficiency testing (PT) or inter-laboratory comparisons (ILC). Participation in PT/ILC programmes is, on the one hand, a tool for demonstrating the laboratory’s performance, on the other hand an aid for maintaining the quality of available concrete tests and validating test methods. Positive evaluation is a confirmation of the laboratory’s capability for performing the tests. The paper presents the results of laboratory proficiency tests carried out by means of inter-laboratory comparisons, as shown in the example of quality assessment of ready-mixed concrete for nine participating laboratories. The tests were performed for concrete of the following parameters: strength class C30/37, consistency S3, frost resistance degree F150, and water resistance degree W8. This involved determining consistencies, air content and density of the concrete mix, and compressive strength of hardened concrete. For the evaluation of laboratory performance results, z-score, ζ-score and En-score were applied. The innovation of the proposed study lies in employing both classical and iterative robust statistical methods. In comparison with classical statistical methods, robust methods ensure a smaller impact of outliers and other anomalies on the measurement results. Following the analyses, clear differences were found between the types of detected discrepancy of test results, which occurred due to the nature of individual parameters. For two laboratories, two scores revealed unsatisfactory results for concrete mix consistency. The main reasons can be pouring into the cone-shaped form a concrete mixture that is too dry, or incorrect use of a measuring tool also creating a possibility that the obtained value can be wrongly recorded. Other possible reasons are discussed in the paper. Participation in inter-laboratory comparison programmes is undoubtedly a way to verify and raise the quality of tests performed for concrete mix and hardened concrete, whereas individual analysis of the results allows the laboratory quality system to be improved.

Preparation and Certification of Indian Reference Material of Bituminous Coal

Certified reference materials (CRMs) are used for evaluating analytical methods, quality assurance and traceability of analytical results to international standards. Bituminous coal is the medium grade coal with high heating capacity and low moisture content. CRM of bituminous coal powder (BND 5101A) has been developed and certified for ash, gross calorific value (GCV),volatile matter (VM) and total sulphur (S) content as 22.16 ± 0.15%; 6114 ± 44 kcal/kg; 29.2 ± 0.36% and 0.71 ± 0.04%, respectively. The sample of coal selected for the purpose is high-rank bituminous type, which was collected from an opencast mine of Central Coalfields Ltd. The work has been carried out jointly by CSIR-Central Institute of Mining and Fuel Research (CSIR-CIMFR), Dhanbad and CSIR-National Physical Laboratory (CSIR-NPL), New Delhi. Proficiency testing (PT) program was carried out among 28 reputed coal laboratories of the country in accordance with ISO/IEC 17043:2010. Based on the performance of laboratories in the PT program, 8 laboratories were selected for inter-laboratory comparison (ILC) program as per ISO 13528:2015. This paper describes the methodology employed for the preparation of a coal reference material, homogeneity, stability studies and the ILC analytical and statistical work performed for the certification of the contents of ash, GCV, VM and total S.

Evaluation of veterinary laboratory proficiency based on results of interlaboratory comparisons organized by FGBI “ARRIAH” in 2018–2019

Laboratory diagnosis is a crucial component in implementation of the set of anti-epidemic measures aimed at contagious animal disease control. The need for unswerving trust in the quality of laboratory performance is a matter of importance not only for service providers and customers, but also for inspecting organiza­tions, accreditation bodies, etc. that establish performance requirements for diagnostic laboratories. Incorrect laboratory test results can lead to a misdiagnosis and, therefore, to grave consequences. One of the forms of experimental verification of a laboratory’s performance with a view to determine the laboratory’s competence and to verify its compliance with accreditation criteria as part of inspection control of the laboratory’s activities is interlaboratory comparison. The laboratory can prove its competence at a particular time, as well as clearly demonstrate how stable the quality of its test results is by summarizing and analyzing the results of its participation in interlaboratory comparisons. The analysis of the results of the interlaboratory comparisons (programmes for detection of causative agents or antibodies to the causative agents of avian influenza, Newcastle disease, rabies, classical swine fever, African swine fever, bluetongue, lumpy skin disease) organized by the FGBI “ARRIAH” for the veterinary laboratories of the Russian Federation in 2018–2019 is presented. The results showed that most of the laboratories had passed the tests successfully. The results submitted by participants were unsatisfactory in some interlaboratory comparison programmes (rabies virus detection using fluorescent antibody technique; detection of avian influenza, classical swine fever and lumpy skin disease viruses using polymerase chain reaction). That highlights the need for those participants who failed the tests to improve their laboratory testing quality.

Persistence of PNH Clones over Time: Insights from the Mid-Term Analysis of the French Nation-Wide Multicenter Prospective Observational Study

Introduction: Since the publication of the International Guidelines (Borowitz, 2010; Illingworth, 2018), no study has assessed the long-term evolution of paroxysmal nocturnal hemoglobinuria (PNH) clones using high-resolution flow cytometry. The sole evaluation, performed by Sugimori et al, using a 2-color flow cytometry test, showed the disappearance of PNH clones in 24% of patients with bone marrow (BM) failure over 5 years (Sugimori, 2009). A diagnostic practice harmonization using high-resolution flow cytometry has spread in France since 2013 through an on-going inter-laboratory comparison program (Debliquis, 2015). Thus, our HPNAFC group has been able to initiate a French nation-wide multicenter prospective observational study. Objective: We aimed to assess the evolution of PNH clones over a long term period using mostly high sensitivity test, which is required for minor clone assessment, with validated flow cytometry data. Methods: All patients of any age with a PNH clone or GPI-deficient cells ≥0.01%, newly- or previously-diagnosed, detected in France from February 29th 2016, could be included in this Observatory, provided that the center had validated a PNH flow cytometry quality control. For each patient, the baseline assessment was always considered as the initial PNH clone detection, even if it occurred before the initiation of the Observatory. Thus, this strategy allowed the collection of cases with long-term follow-up. Referent cytometrist of each center included patients in the e-CRF available on the HPNAFC website providing clinical and biological information as well as flow cytometry raw data files. This study was approved by the national research ethics board. Results: As of July 15th 2019, 48 participating flow cytometry laboratories across France have enrolled 356 patients with a PNH clone or GPI-deficient cells ≥ 0.01%. All cases have been carefully reviewed by the 2 principal investigators, who both thoroughly re-examined flow cytometry data and the e-CRF filling that led to the update of roughly one third of the submitted files. This enabled the validation of 200 patients at diagnosis, the remaining 156 being ongoing. One hundred and three of the 200 validated patients displayed at least one follow-up point (more than 3 months apart from the diagnosis) with a clone size determined at diagnosis (see flow chart figure 1A). For 8/103 patients, exchanges with centers are still ongoing. Thus, we were able to assess the evolution of PNH clones of 95 patients with 2 [range: 1-8] follow-up points over a period of 4.1 [0.3-14.2] years, corresponding to 200 validated follow-up points. The patient median age at diagnosis was 40 years old [10-85] with 3 pediatric cases (&lt;18y) and a M/F sex ratio of 0.86. Diagnoses were made between 2003 and 2018 with clinical information available in 97% of cases: 19 patients (20%) had hemolytic anemia and most patients (n=73, 77%) displayed BM failure including aplastic anemia (n=62), myelodysplastic syndrome (n=7) and unexplained cytopenia(s) (n=4). No case of thrombosis was included. All patients with hemolytic anemia showed an increasing clone size over time including the two who were not treated with eculizumab (Figure 1B; median size at diagnosis on neutrophils: 81.3% vs median size over 5 years: 96.3%). The median clone size at diagnosis for patients with BM failure was 1.5% on neutrophils with a very wide range [0.01-97.87], almost half of them being less than 1%. When comparing the diagnosis point with the latest follow-up point, PNH clone size increased in 37 patients, decreased in 16 of them and remained stable in 20 cases (Figure 1C, D). Nine of the 37 patients reached a PNH clone size above 50% and 4 of them received a treatment by eculizumab in a median delay of 5 years [1.5-6.0]. Interestingly, no patient showed spontaneous disappearance of PNH clones, pending the use of a high-resolution flow cytometry test. The only five patients with undetectable PNH clones (Figure 1D, red lines) were those who underwent BM transplantation. Conclusion: This multicenter study based on robust flow cytometry analysis showed no disappearance of PNH clones, including minor ones, over a long period of time, regardless of the clinical manifestations, except for patients who underwent BM transplantation. Moreover, PNH clone size increased in half of patients with BM failure, justifying a long term PNH clone size monitoring, even in these patients. Figure 1 Disclosures Le Garff-Tavernier: Alexion: Consultancy, Honoraria. Pruvot Debliquis:Alexion: Honoraria; Takeda: Honoraria; Pfizer: Honoraria; Gilead: Honoraria; Genzyme: Honoraria. Socie:Alexion: Consultancy. Peffault de Latour:Alexion: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Amgen: Research Funding. Drenou:Alexion: Consultancy, Honoraria. Wagner Ballon:Alexion: Consultancy, Honoraria.

Practice Patterns in Urinary Cytopathology Prior to the Paris System for Reporting Urinary Cytology

The Paris System for Reporting Urinary Cytology has been disseminated since its inception in 2013; however, the daily practice patterns of urinary tract cytopathology are not well known. To assess urinary tract cytopathology practice patterns across a variety of pathology laboratories to aid in the implementation and future update of the Paris System for Reporting Urinary Cytology. A questionnaire was designed to gather information about urinary tract cytopathology practices and mailed in July 2014 to 2116 laboratories participating in the College of American Pathologists interlaboratory comparison program. The participating laboratories' answers were summarized. Of the 879 of 2116 laboratories (41%) that participated, 745 (84.8%) reported processing urinary tract specimens in house. The laboratories reported processing various specimen types: voided urine, 735 of 738 (99.6%); bladder washing/barbotage, 639 of 738 (86.6%); and catheterized urine specimens, 653 of 738 (88.5%). Some laboratories used multiple preparation methods, but the most commonly used preparation techniques for urinary tract specimens were ThinPrep (57.4%) and Cytospin (45.5%). Eighty-eight of 197 laboratories (44.7%) reported preparing a cell block, but with a low frequency. Adequacy criteria were used by 295 of 707 laboratories (41.7%) for voided urine, and 244 of 707 (34.5%) assessed adequacy for bladder washing/barbotage. More than 95% of the laboratories reported the use of general categories: negative, atypical, suspicious, and positive. Polyomavirus was classified as negative in 408 of 642 laboratories (63.6%) and atypical in 189 of 642 (29.4%). One hundred twenty-eight of 708 laboratories (18.1%) performed ancillary testing, and of these, 102 of 122 (83.6%) reported performing UroVysion. Most laboratories use the ThinPrep method followed by the Cytospin technique; therefore, the criteria published in The Paris System for Reporting Urinary Cytology, based mostly on ThinPrep and SurePath, should be validated for Cytospin, and relevant information should be included in the revised edition of The Paris System for Reporting Urinary Cytology.

EQRAIN: uranium and plutonium interlaboratory exercises from 1997 to 2016—comparison to ITVs-2010

Since 1987, the CEA’s Committee for the establishment of analysis methods (CETAMA) has regularly implemented interlaboratory comparisons, entitled “evaluation of the quality results of analysis in the nuclear industry” (EQRAIN). Notably, the EQRAIN U and EQRAIN Pu interlaboratory comparisons assess proficiency in measuring a mass content of uranium or plutonium in reference solutions. This paper presents the results of measurement uncertainty assessments from EQRAIN U and EQRAIN Pu comparisons over 20 years of exercises (1997–2016). The mathematical approach developed in this work allowed to estimate the impact of short-term systematic and random errors to the overall uncertainty of each analytical method used in the interlaboratory comparison program. This statistical analysis shows a good consistency between measurement uncertainty values from EQRAINs and the measurement uncertainty target values established by the International Atomic Energy Agency for nuclear material balances (ITVs-2010).

The equivalence of the Calcium‐Acetate‐Lactate and Double‐Lactate extraction methods to assess soil phosphorus fertility

AbstractA large variety of extraction methods are used worldwide for the estimation of “plant‐available P” in soils. In Germany, the standard extractants are Calcium‐Acetate‐Lactate (CAL) and Double‐Lactate (DL). Until now there is no validated transformation procedure available and studies on the comparability of both methods have reported conflicting evidence. The uncertainty about the equivalence of CAL‐P and DL‐P hinders a direct comparison of the P fertility status and P fertilizer recommendations across Germany. Based on 136 datasets for soil samples from an interlaboratory comparison program and three P fertilization field trial sites, for which plant‐available P had been determined by both the CAL and DL method, we assessed the comparability of both extraction methods and derived simple and multiple regression equations to transform DL‐P into CAL‐P values. On average, DL extracted 30% more P than CAL. However, this strongly depended on soil pH and carbonate content. A simple linear regression model explained 70% of the variance. However, if simple linear regression models were fitted to pH‐specific samples (pH range 4.5 to 7.0) the R2 increased to 0.96. Based on an independent validation dataset (n = 48) we demonstrated that such pH‐specific models were more accurate than models that did not consider pH when transforming DL‐P to CAL‐P values. Multiple regression results showed that out of soil pH, Corg, Nt, and C : N ratio, only soil pH improved the model. The transformation equations in this study provide a step towards an improved comparability of P fertility status assessments of soils across Germany.

An investigation of the base metal thermocouples uncertainty components in ILC comparison

This paper is about unique the interlaboratory large comparison organized under EA-2/14 - Procedure for Regional Calibration ILCs in Support of EA MLA and describe final results of the comparison and several pitfalls when measuring temperature with base metal thermocouple. Interlaboratory comparison (ILC) serves as a tool for comparison of measurement results carried out by accredited or non-accredited calibration laboratories in the relevant field of measurement. ILC represents very effective means to demonstrate technical competence of the participant and also serves as a technical base for accreditation. The subject of this comparison was calibration of several pieces the N-type thermocouples. The pilot laboratory of this ILC was the Department of primary metrology of thermo-technical quantities of the Czech Metrology Institute. The reference values of the test items were provided by the above mentioned organizational unit this company. The evaluation of the measurement results of participating laboratories was performed on the basis of En score (EN ISO/IEC 17043). In this ILC program 47 accredited calibration laboratories from different European countries and also from Bosnia and Hercegovina, Switzerland and Turkey have participated. The results of this comparison demonstrate satisfactory agreement of the majority of the participants measured values with the reference ones within their stated expanded uncertainties. The article also highlights the basic and often neglected components of uncertainty.