scholarly journals ANA IIF Automation: Moving towards Harmonization? Results of a Multicenter Study

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Stefanie Van den Bremt ◽  
Sofie Schouwers ◽  
Marjan Van Blerk ◽  
Lieve Van Hoovels
Keyword(s):  
External Quality Assessment ◽  
Microscopic Analysis ◽  
Quality Assurance Program ◽  
Serum Samples ◽  
External Quality ◽  
Interlaboratory Variability ◽  
Three Samples ◽  
Single Well ◽  
Lower Titer ◽  
Endpoint Titer

Background. Our study aimed to investigate whether the introduction of automated anti-nuclear antibody (ANA) indirect immunofluorescence (IIF) analysis decreases the interlaboratory variability of ANA titer results. Method. Three serum samples were sent to 10 laboratories using the QUANTA-Lyser® in combination with the NOVA View®. Each laboratory performed the ANA IIF analysis 10x in 1 run and 1x in 10 different runs and determined the endpoint titer by dilution. One of the three samples had been sent in 2012, before the era of ANA IIF automation, by the Belgian National External Quality Assessment (EQA) Scheme. Harmonization was evaluated in terms of variability in fluorescence intensity (LIU) and ANA IIF titer. Results. The evaluation of the intra- and interrun LIU variability revealed a larger variability for 2 laboratories, due to preanalytical and analytical problems. Reanalysis of the EQA sample resulted in a lower titer variability. Diluted endpoint titers were similar to the estimated single well titer and the overall median titer as reported by the EQA in 2012. Conclusion. The introduction of automated microscopic analysis allows more harmonized ANA IIF reporting, provided that this totally automated process is controlled by a thorough quality assurance program, covering the total ANA IIF process.

scholarly journals Establishment of an Experimental Procedure for Preparing Trial Serum Samples for the Specific Serodiagnosis of Toxocara canis for External Quality Assessment Schemes

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Quang Huy Vu ◽  
Diep Tuan Tran ◽  
Phu Manh Sieu Tran ◽  
Van Chuong Le ◽  
Thi Diem Phuc Huynh ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Western Blotting ◽  
Freeze Drying ◽  
External Quality Assessment ◽  
Toxocara Canis ◽  
Serum Samples ◽  
External Quality ◽  
Experimental Procedure ◽  
The Stability ◽  
Anti Hiv

Background. External quality assessment (EQA) provides evidence of reliable, accurate, and precise results for customers using the diagnostic test for Toxocara canis. Objective. To establish a procedure for producing standard Toxocara canis serum samples for serodiagnostic testing in EQA. Methods. The collected serum samples to contain anti-Toxocara canis antibodies were screened by ELISA and confirmed by Western blotting. These samples were found to be negative for other helminth antibodies, anti-HIV-1 and -2 antibodies, anti-HCV antibodies, and antibodies to HBs antigen. The sera were divided, processed by both freeze-drying and freezing methods, and then stored. The stability and homogeneity of the samples were evaluated after 7 days, 1 month, 3 months, and 6 months. An F-test and a T-test were applied to evaluate their homogeneity and stability. Results. Among eleven samples positive by ELISA, ten of them were confirmed via Western blotting by positive reaction with 5 specific Toxocara canis bands. Two lots of trial standard sera containing specific anti-Toxocara canis antibodies were successfully produced. Lot DK had a concentration of 31.01±1.1 NovaTec Units (NTU), and Lot DL had a concentration of 27.18±0.9 NTU. After storage at -80°C, the samples prepared by the freeze-drying method were stable for at least 3 months, and the samples prepared by the freezing method were stable for 6 months (p>0.05). Samples produced by both methods were stable for 7 days at 30°C (p>0.05). Conclusion. Specific serodiagnosis samples of anti-Toxocara canis antibodies for EQA could be produced that possessed homogeneity and stability lasting for 3 months and 6 months by the freeze-drying and freezing methods, respectively. At 30°C, the samples produced by both methods were stable for 7 days, suitable for delivery to remote laboratories.

Evaluation of the Kodak Ektachem Glucose and Urea Methods

1980 ◽  
Vol 17 (6) ◽  
pp. 293-300 ◽  
Author(s):  
Penelope M S Clark ◽  
Larry J Kricka ◽  
Thomas P Whitehead
Keyword(s):  
Cerebrospinal Fluid ◽  
Analytical Methods ◽  
External Quality Assessment ◽  
Calibration Model ◽  
Tetraacetic Acid ◽  
Pleural Effusions ◽  
Serum Samples ◽  
External Quality ◽  
Control Serum ◽  
Calibration Parameters

An evaluation of the Kodak Ektachem glucose and urea methods is described. Aspects evaluated included precision, linearity, accuracy, correlation with routine methods, interferences (haemoglobin, bilirubin, protein, dextran, lipaemia, ethylene-diamine tetraacetic acid, fluoride/oxalate, and heparin), and carryover. Stability and batch-to-batch variation in glucose and urea reagents were also investigated. The performance of the Ektachem glucose and urea methods was shown to be as satisfactory as conventional analytical methods. The requirement to reconstitute control serum samples in a bicarbonate diluent in order to obtain accurate results presents problems for the analysis of lyophilised specimens circulated by external quality assessment schemes. The complex calibration model and the significance of variation in the calibration parameters need further explanation. The Ektachem methods are designed specifically for use with human serum. However, the methods performed satisfactorily with cerebrospinal fluid, pleural effusions, and animal serum but not with urine.

Anti-ganglioside antibodies: experience from the Italian Association of Neuroimmunology external quality assessment scheme

2018 ◽  
Vol 56 (11) ◽  
pp. 1921-1925 ◽  
Author(s):  
Diego Franciotta ◽  
Matteo Gastaldi ◽  
Tiziana Biagioli ◽  
Luana Benedetti ◽  
Claudia Giannotta ◽  
...  
Keyword(s):  
Quality Assessment ◽  
External Quality Assessment ◽  
Real Life ◽  
Laboratory Diagnostics ◽  
Serum Samples ◽  
External Quality ◽  
External Quality Assessment Scheme ◽  
Italian Association ◽  
Commercial Line ◽  
Ganglioside Antibodies

Abstract Background Anti-ganglioside antibodies are currently used in the differential diagnosis of suspected immune-mediated neuropathies. In-house and increasingly used commercial assays seem to perform suboptimally, and comparative information on their analytical performance are essentially lacking. Born within the frame of guidelines and standardization activities by the Italian Association of Neuroimmunology, this external quality assessment scheme (EQAS) is a real-life snapshot of the laboratory diagnostics in this field. Methods The EQAS consisted of five surplus, anonymized serum samples from patients with clinically-defined neuropathies and two serum samples from healthy blood donors. Eight laboratories used commercial line-/dot-blots, seven in-house/commercial ELISAs (in addition, 13 laboratories tested a recently released ELISA by Bühlmann). Only high anti-ganglioside antibody reactivities were considered, in accordance with consolidated recommendations. Results Large variations in anti-ganglioside antibody profiles were observed, even, although to a lesser extent, within homogeneous classes of assays. Concordance between the profiles and clinical phenotypes was also partial. Conclusions Although conducted on a relatively small, but representative number of Italian laboratories, this EQAS shows a critical between-laboratory disagreement in the test results of anti-ganglioside antibodies. Also considering the trend for using certified assays in generalist laboratories, strong efforts toward standardization and the identification of the best method(s) for their determinations are compellingly needed.

scholarly journals Results of the first pilot external quality assessment (EQA) scheme for anti-SARS-CoV2-antibody testing

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Verena Haselmann ◽  
Mustafa K. Özçürümez ◽  
Frank Klawonn ◽  
Volker Ast ◽  
Catharina Gerhards ◽  
...  
Keyword(s):  
Quality Assessment ◽  
External Quality Assessment ◽  
Clinical Performance ◽  
Individual Performance ◽  
Infection Prevalence ◽  
Serological Testing ◽  
Antibody Testing ◽  
Serum Samples ◽  
External Quality ◽  
Raw Data

AbstractObjectivesAssessment 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.MethodsThe 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.ResultsThe 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.ConclusionsEven 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.

Performance of Proficiency Survey Samples in Two Immunoradiometric Assays of Human Growth Hormone and Comparison with Patients' Samples

1992 ◽  
Vol 38 (4) ◽  
pp. 553-557 ◽  
Author(s):  
P J Pringle ◽  
J Jones ◽  
P C Hindmarsh ◽  
M A Preece ◽  
C G Brook
Keyword(s):  
Growth Hormone ◽  
Quality Assessment ◽  
Human Growth Hormone ◽  
Matrix Effect ◽  
External Quality Assessment ◽  
Human Growth ◽  
Immunoradiometric Assay ◽  
Serum Samples ◽  
External Quality ◽  
External Quality Assessment Scheme

Abstract The immunoradiometric assay (IRMA) used in our laboratory for the measurement of growth hormone (hGH; somatotropin) performed badly in the national proficiency survey program, the U.K. External Quality Assessment Scheme (EQAS). We compared our assay with another IRMA, which gave similar results for patients' samples and performed adequately in EQAS. The samples from EQAS are collected from patients with polycythemia and fall into two categories: those containing endogenous hGH and those supplemented with pituitary-derived hGH. Analysis of the two groups separately showed that the differences between the two IRMAS were in the measurement of the endogenous hormone. The reason for this appears to be a matrix effect related to the fact that the EQAS serum samples are collected from polycythemic patients.

scholarly journals Interlaboratory Variability in the Quantification of New Generation Antiepileptic Drugs Based on External Quality Assessment Data

Epilepsia ◽  
2003 ◽  
Vol 44 (1) ◽  
pp. 40-45 ◽  
Author(s):  
John Williams ◽  
Meir Bialer ◽  
Svein I. Johannessen ◽  
Günther Krämer ◽  
René Levy ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Antiepileptic Drugs ◽  
External Quality Assessment ◽  
Assessment Data ◽  
External Quality ◽  
Interlaboratory Variability ◽  
New Generation

Calibration of Local Systems with Lyophilized Calibrant Plasmas Improves the Interlaboratory Variability of the INR in the Italian External Quality Assessment Scheme

1999 ◽  
Vol 82 (12) ◽  
pp. 1621-1626 ◽  
Author(s):  
Veena Chantarangkul ◽  
Bruno Cesana ◽  
Pier Mannuccio Mannucci ◽  
Armando Tripodi
Keyword(s):  
Quality Assessment ◽  
Statistical Approach ◽  
External Quality Assessment ◽  
Geometric Mean ◽  
Local System ◽  
Sensitivity Index ◽  
Local Calibration ◽  
External Quality ◽  
External Quality Assessment Scheme ◽  
Interlaboratory Variability

SummaryCalibration with lyophilized calibrant plasmas certified in terms of PT with International Reference Preparations for thromboplastin has been proposed to minimize the effect of coagulometers on the INR. Aim of this study was to test the ability of local calibration with lyophilized calibrant plasmas, combined with a modified statistical approach, to improve the interlaboratory variability of the INR measured on two test plasmas (one coumarin and one artificially-depleted) by participants in the External Quality Assessment Scheme (EQAS). Sets of lyophilized calibrant and test plasmas were sent to the participants in the EQAS, who were asked to determine PT with their own reagent/ instrument combination (local system). Results were returned as PT together with information on the type of local system, the stated International Sensitivity Index (ISI) and the geometric mean of PTs determined by testing with the local system fresh plasmas from 20 healthy subjects. Ninety-two participants using 9 and 11 brands of reagents and instruments returned results. The CV of the INR determined with the stated ISI for the coumarin (Mean INR = 4.39) and artificially-depleted (Mean INR = 4.23) test plasmas were 11.2% and 10.3% and were reduced on the average by 34% and 54%, respectively, when the INR was calculated with the local ISI.In conclusions, results from this field study involving laboratories and testing systems representative of the real situation in oral anticoagulant monitoring in our country, indicate that local calibration by artificially-depleted plasmas, combined with the proposed statistical approach, is suitable to improve the interlaboratory agreement on the INR.

scholarly journals The Importance of Commutability of Reference Materials Used as Calibrators: The Example of Ceruloplasmin

2013 ◽  
Vol 59 (9) ◽  
pp. 1322-1329 ◽  
Author(s):  
Ingrid Zegers ◽  
Robert Beetham ◽  
Thomas Keller ◽  
Joanna Sheldon ◽  
David Bullock ◽  
...  
Keyword(s):  
Reference Material ◽  
Quality Assessment ◽  
Reference Materials ◽  
External Quality Assessment ◽  
Serum Samples ◽  
External Quality ◽  
Measurement Results ◽  
Materials Used ◽  
The Uk ◽  
Good Linear Correlation

BACKGROUND Different methods for ceruloplasmin tend to give different results in external quality assessment schemes. During the production of the certified reference material ERM-DA470k/IFCC discrepant measurement results were also found for ceruloplasmin measured with different methods, and consequently the protein could not be certified in the material. METHODS We performed a commutability study with 30 serum samples and the reference materials ERM-DA470, ERM-DA470k/IFCC, and ERM-DA472/IFCC, using 6 different methods. Data were analyzed according to the CLSI Guideline C53-A to assess whether the reference materials had the same behavior as the serum samples with respect to measurement results obtained with combinations of the methods used. RESULTS Measurement results from different methods showed a good linear correlation for the serum samples. ERM-DA470 showed marked noncommutability for certain combinations of methods. ERM-DA470k/IFCC and ERM-DA472/IFCC were commutable for more combinations of methods. The lack of commutability of ERM-DA470 for certain combinations of methods correlates with results from the UK National External Quality Assessment Service showing discrepancies between results from these methods. For serum stored in the presence of sodium azide the results from different methods are essentially equivalent. CONCLUSIONS Ceruloplasmin in ERM-DA470 is a fully documented example of a situation in which, due to lack of commutability, the use of a common material for calibration did not lead to harmonization .

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