Comparison Of Analytical Performance Research Articles

B-164 Comparison of Analytical Performance of Two Processing Methods for Measurement of Zinc and Copper on Triple Quadrupole Inductively Coupled Plasma Mass Spectrometer

Abstract Background Copper (Cu) and zinc (Zn) are essential cofactors of enzymes involved in several metabolic processes required for the development of tissue structures and immune response, especially in pediatrics and pregnant women. Triple quadrupole inductively coupled plasma mass spectrometer (ICP-QQQ) enables simultaneous precise quantification of multiple elements with high throughput, sensitivity, and specificity. Samples are introduced into ICP-QQQ as a liquid and converted to fine aerosol with the help of a nebulizer and spray chamber. The precision and sensitivity of measured metals are dependent on the sample preparation thus, this study focuses on comparing the analytical performances between two sample preparations: 0.5% nitric acid (HNO3) as the only diluent (Diluent A) versus a combination of 0.5% HNO3 along with 1% ethanol, 0.5% Ammonium hydroxide, 0.02% TritonX-100, and 0.1% HNO3 (Diluent B) for Cu and Zn metal analysis in serum using ICP-QQQ. Methods Twenty deidentified randomly selected patient serum samples were prepared with either diluent A or diluent B and analyzed by ICP-QQQ (Agilent 8900). Data were analyzed using EP Evaluator. Bland-Altman analysis was used to determine the agreement between the two sample preparations. Deming regression analysis was used to determine other analytical performances, such as the proportional and constant bias of Zn and Cu concentration. Results There was a bias of -4.8 and -3.0 between the two sample preparation methods when analyzing Cu and Zn, respectively. The mean of Cu-Diluent B versus Cu—Diluent A was 125.2 ± 28.3 µg/dL and 120.4 ± 29.8 µg/dL, respectively, with a slope of 1.070. Conversely, the Zn comparison study shows a lower slope (0.769) with a mean of 71.0 ± 20.5 and 68.0 ± 16.1 µg/dL for Zn-Diluent B and Zn-Diluent A, respectively. Conclusions Samples prepared with nitric acid solution only (Diluent A) appeared to show negative bias compared to Diluent B solution containing triton-X for both metals. However, the bias is within the total allowable error for zinc and copper. Importantly, Zn-sample analysis with diluent A (HNO3 only) shows a 23% proportional bias, which is absent with copper sample analysis. A larger study is needed to further compare several methods of sample preparation in ICP-QQQ analysis while leveraging simple preparation without compromising analytical sensitivity. Overall, this study shows that both methods of sample preparation can be effectively used in the ICP-QQQ analysis of serum copper and zinc.

Comparison of analytical performance and economic value of two biosurveillance methods for tracking SARS-COV-2 variants of concern.

The development of biosurveillance programs with strong analytical performance and economically accessible protocols is essential for monitoring viral pathogens. Throughout the COVID-19 pandemic, whole-genome sequencing (WGS) has been the prevailing technology for SARS-CoV-2 variant of concern (VOC) detection. While WGS offers benefits, it is a lengthy process, financially and technically straining for scalable viral tracking. The aim of this study was to compare the analytical performance and economic feasibility of WGS and PCR mutation panels for distinguishing six known VOCs: Alpha (B.1.1.7 and Q.4), Gamma (P.1), Delta (B.1.617.2 and AY.4.2), and Omicron. (B.1.1.529.1). In all, 78 SARS-CoV-2-positive samples were collected from April to December 2021 at Northeastern University (Cabot Testing Site, Boston, MA, USA) for genotyping PCR and WGS analysis. MagMax Viral/Pathogen II Nucleic Acid Isolation and TaqPath COVID-19 Combo Kits were used for RNA extraction and SARS-CoV-2 confirmation. VOC discrimination was assessed using two TaqMan SARS-CoV-2 single nucleotide polymorphism (SNP) assay layouts, and Ion Torrent WGS. In November 2021, the mutation panel demonstrated marked versatility by detecting the emerging Omicron variant reported by South Africa. SNP panel analysis yielded the following 78 VOC identifications: Alpha B.1.1.7 (N = 20), Alpha Q.4 (N = 3), Gamma P.1 (N = 1), Delta B.1.617.2 (N = 30), Delta AY.4.2 (N = 3), and Omicron B.1.1.529.1 (N = 20) with one undetermined (N = 1) sample. Genotyping mutation panels designated lineages in 77 of 78 samples, 46/78 were confirmed by WGS, while 32 samples failed WGS lineage assignment. RT-PCR genotyping panels offer pronounced throughput and sensitivity and provide an economically advantageous technique for SARS-CoV-2 biosurveillance.IMPORTANCEThe results presented in our manuscript demonstrate how the value of simplistic and reliable molecular assays coupled with the core scientific principle of standardization can be overlooked by the charm of more sophisticated assays and instrumentation. This effect can often be amplified during tumultuous public health events, such as the COVID-19 pandemic. By adapting standardized PCR mutation panels to detect prominently circulating SARS-CoV-2 variants, we were able to better assess the potential health impacts of rising positivity rates and transmission clusters within the Northeastern University population. While several literature publications utilizing genotyping PCR and NGS have a similar scope to ours, many investigations lack sufficiently standardized genotyping PCR and NGS bioinformatics inclusionary/exclusionary criteria for SARS-CoV-2 variant identification. Finally, the economic benefits of standardized PCR mutation panels would allow for global implementation of biosurveillance, rather than reserving biosurveillance to more economically developed nations.

A-374 Analytical Performance Assessment and Comparison of Point of Care Testing (POCT) Devices for Blood Lipids Measurements

Abstract Background Cardiovascular diseases (CVDs) are the leading cause of death in the U.S. and worldwide. According to the World Health Organization (WHO), worldwide, 85% of CVD deaths are due to heart disease and strokes, and over 75% occur in low- and middle-income countries (LMICs). Early detection and treatment are key to preventing the consequences of CVD. Point-of-care testing (POCT) devices offer alternatives to screening large populations for CVD risk. Although POCT are increasingly used for screening, only few information is available about their accuracy and reliability. Methods Eight POCT devices for blood lipids that previously successfully participated in the CDC CVD Biomarker Standardization Programs were used in this preliminary study. The analytical performance for all eight devices was assessed using split sample comparisons to the CDC reference measurement procedures for measurements performed in whole blood (WB) and serum. Specifically, the accuracy of total cholesterol (TC) was determined in WB and serum. The accuracy of high-density lipoprotein-cholesterol (HDL-c), and low-density lipoprotein-cholesterol (LDL-c) was determined in serum. The precision of TC, HDL-c, LDL-c, and triglycerides (TG) was determined in WB and serum. Results The reference values of the specimens from 20 donors ranged between 154–279 mg/dL, 36.9–109 mg/dL, and 71.1–182 mg/dL for TC, HDL-c, and LDL-c in serum, and between 145–210 mg/dL for TC in WB. Preliminary assessments found that the mean bias for each instrument ranged from -7.86%–13.82% and from -11.90%–3.24% for TC in WB and serum, respectively. For serum HDL-c samples, the mean bias ranged from −6.81%–15.43%. The mean bias for serum LDL-c samples ranged from −22.40% to 3.08%. For three devices, approximately 30% of the WB measurements and approximately 50% of the serum measurements were reported as outside of the measurement range. The mean imprecision for each instrument ranged from 2.2%–13.75% and from 1.88%–11.76% for TC in WB and serum, respectively. For HDL-c, the mean imprecision ranged from 5.36%–23.21% and from 2.30% to 26.69% in WB and serum, respectively. The mean imprecision ranged from 4.82%–20.34% and from 3.06%–20.54% for LDL-c in WB and serum, respectively. For TG, the mean imprecision ranged from 5.78%–23.91% and from 1.71%–11.02% in WB and serum, respectively. Conclusion These preliminary findings about the analytical performance of POCT devices indicate notable differences in accuracy and precision for lipids measured in WB and serum, with serum measurements being more likely within performance requirements than WB measurements. Some devices appear to be more likely to report values outside the measurement range even though reference values are within the measurement range of the device. Further studies to verify these preliminary findings with more individual donor samples are underway.

Abstract P6-04-14: Comparison of next-generation sequencing and real-time PCR for PIK3CA testing in hormone receptor-positive/HER2-negative breast cancer on metastatic and matched primary tumor samples

Abstract Introduction: Based on the SOLAR-1 study, the PI3Kα-specific inhibitor alpelisib has been approved in combination with fulvestrant for postmenopausal women, and men, with HR+/HER2-, PIK3CA-mutated, advanced or metastatic breast cancer (BC). Despite PIK3CA mutations occurring in ⁓40% of HR+/HER2- BC, PIK3CA molecular testing is a new task to be carried out in clinical practice. Adopting the most appropriate testing strategy (RT-PCR vs. NGS) on the most appropriate biological sample is of capital significance in oncologic pathology. Here, we sought to assess the concordance rate for PIK3CA molecular analysis between different technical platforms in both metastatic and matched primary tumors. Methods: From our Institutional registry, n=16 HR+/HER2- metastatic BC, which were found to harbor PIK3CA mutations via next-generation sequencing (NGS) assays [custom panel and Oncomine Comprehensive Assay (OCA) v3 (Thermo Fisher Scientific, Waltham, MA, USA)], were selected. In half of the cases (n=8), matched primary tumors were available and were subjected to PIK3CA testing with NGS. The analytical performance between NGS and a semi-closed RT-PCR (EasyPGX®, Diatech Pharmacogenetics, Italy) was assessed in 13/16 (81.3%) metastatic samples for which archival slides and blocks and/or residual extracted DNA were available, and all the primary tumors. Results: Overall, upfront testing of PIK3CA mutational status with NGS detected genetic alterations in exons 7, 9, and 20. A concordance rate of 100.0% was observed between primary and metastatic tumors. On the other hand, the analysis of primary tumors (n=8) and 13/16 (81.3%) metastatic samples with RT-PCR revealed a concordance of 42.9%. Analytical performance comparison showed that the two technologies were concordant in 7/13 metastatic cases (53.8%). In two of the discordant cases (15.4%), RT-PCR did not identify the PIK3CA mutations due to their absence from its reference range. Interestingly, visual inspection of the RT-PCR raw data increased the concordance to 76.9%. In primary tumors, consensus between the two testing methods was observed in 5 (62.5%) cases. Discussion: The concordance rate analysis shows that upfront PIK3CA molecular testing with NGS appears to be more efficacious compared with RT-PCR. Our data suggest that primary tissues reflect the PIK3CA mutational status when tested with NGS. RT-PCR is simpler with a shorter turnaround time, and less expensive than NGS approaches, however, trained personnel are required for accurate results interpretation. In addition, the limited reference range of this testing method should be taken into account for potential false negative results. Conclusion: In terms of PIK3CA molecular testing, NGS should be the preferred method in comparison with RT-PCR. Primary tumors represent a valid biospecimen to be used for this analysis in the absence of the metastatic sample. Citation Format: Konstantinos Venetis, Francesco Pepe, Elham Sajjadi, Giuseppina Bonizzi, Mariia Ivanova, Davide Vacirca, Alessandra Rappa, Massimo Barberis, Giuseppe Viale, Elena Guerini-Rocco, Elisabetta Munzone, Umberto Malapelle, Nicola Fusco. Comparison of next-generation sequencing and real-time PCR for PIK3CA testing in hormone receptor-positive/HER2-negative breast cancer on metastatic and matched primary tumor samples [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-04-14.

Comparison of analytical performances between clot waveform analysis and FibWave in edoxaban‐treated patients and healthy controls

IntroductionThe activated partial thromboplastin time (aPTT) and the prothrombin time (PT) are widely available coagulation parameters which are however poor predictors of the anticoagulant effect of direct oral anticoagulants (DOACs). Some coagulometers use the clot waveform analysis (CWA) to assess the clotting time but mainly based on a unique parameter. The improvement of these methodologies and the evaluation of the other waveform parameters may increase the sensitivity to DOACs. ObjectivesTo assess the performance of an improved clot waveform an method (i.e. FibWave) to detect the impact of edoxaban on the coagulation and the fibrinolytic systems. MethodsSeventy‐one samples from patients treated with edoxaban collected at minimum concentration (CTROUGH) and/or maximum concentration (CMAX), and 45 control samples were included. The aPTT‐ and PT‐based CWA as well as the FibIn, FibEx, and FibLysis methodologies of the FibWave were implemented and performed on an ACL‐TOP 700. ResultsPT and FibEx clotting time were strongly correlated to edoxaban concentration (Pearson r = 0.80 and 0.89, respectively). The FibEx clotting time allowed a better discrimination for samples with 30 and 50 ng/ml of edoxaban compared to PT (cutoffs of 96.5 and 114.2 s for the FibEx versus a unique cutoff of 13.1 s for the PT). The fibrinolytic process was impaired in the presence of edoxaban in a dose‐dependent manner. ConclusionFibEx is more sensitive than aPTT‐ and PT‐based CWA for the detection of the clinically relevant anticoagulant level of edoxaban.

COMPARISON OF ANALYTIC PERFORMANCE OF RESULTS OF DETERMINATION OF Pb METAL IONS USING ATOMIC ABSORPTION SPECTROPHOTOMETER of VARIOUS in SAMARINDA LABORATORIES

The study about the comparison of analytical performance of the determination of Pb metal ions using Atomic Absorption Spectrophotometer in various laboratories in samarinda has been conducted. The validated methods are linearity, detection limits, quantity and precision limits. The results showed, a standardized regression test obtained by laboratory A, a value of R2 ≥ 0.4103, laboratory B a value of R2 ≥ 0.983 and laboratory C, a value of R2 ≥ 0.000. The detection limit found at laboratory A was 0.6728 µg/L, laboratory B was 0.1989 µg/L and laboratory C was 0.0001 µg/L. The quantization limit obtained by laboratory A was 0.6817 µg/L, laboratory B was 0.6063 µg/L and laboratory C was 0.0001 µg/L. The precision test of laboratory A was 7.2208, laboratory B was 5.4557 and laboratory C was 0,000. The result of determining Pb of gas station soil samples in laboratory A is 0.737 µg/L and laboratory B is 0.391 µg/L, so that means they have exceeded the quality standards set by the Indonesian National Standard (INS).

Analytical performance comparison of four SARS-CoV-2 RT-qPCR primer-probe sets for wastewater samples

Current studies have confirmed the feasibility of SARS-CoV-2 RNA detection by RT-qPCR assays in wastewater samples as an effective surveillance tool of COVID-19 prevalence in a community. Analytical performance of various RT-qPCR assays has been compared against wastewater samples based on the positive ratio. However, there is no systematic comparison work has been conducted for both analytical sensitivity and quantitative reliability against wastewater, which are essential factors for WBE. In this study, the detection performance of four RT-qPCR primer-probe sets, including CCDC-N, CDC-N1, N-Sarbeco, and E-Sarbeco, was systematically evaluated with pure synthetized plasmids, spiked wastewater mocks and raw wastewater samples. In addition to confirm RT-qPCR results, Nanopore sequencing was employed to delineate at molecular level for the analytical sensitivity and reproducibility of those primer-probe sets. CCDC-N showed high sensitivity and the broadest linearity range for wastewater samples. It was thus recommended to be the most efficient tool in the quantitative analysis of SARS-CoV-2 in wastewater. CDC-N1 had the highest sensitivity for real wastewater and thus would be suitable for the screening of wastewater for the presence of SARS-CoV-2. When applying the primer-probe sets to wastewater samples collected from different Australian catchments, increased active clinical cases were observed with the augment of SARS-CoV-2 RNA quantified by RT-qPCR in wastewater in low prevalence communities.

Ultrasensitive On-Field Luminescence Detection Using a Low-Cost Silicon Photomultiplier Device.

The availability of portable analytical devices for on-site monitoring and rapid detection of analytes of forensic, environmental, and clinical interest is vital. We report the development of a portable device for the detection of biochemiluminescence relying on silicon photomultiplier (SiPM) technology, called LuminoSiPM, which includes a 3D printed sample holder that can be adapted for both liquid samples and paper-based biosensing. We performed a comparison of analytical performance in terms of detectability with a benchtop luminometer, a portable cooled charge-coupled device (CCD sensor), and smartphone-integrated complementary metal oxide semiconductor (CMOS) sensors. As model systems, we used two luciferase/luciferin systems emitting at different wavelengths using purified protein solutions: the green-emitting P. pyralis mutant Ppy-GR-TS (λmax 550 nm) and the blue-emitting NanoLuc (λmax 460 nm). A limit of detection of 9 femtomoles was obtained for NanoLuc luciferase, about 2 and 3 orders of magnitude lower than that obtained with the portable CCD camera and with the smartphone, respectively. A proof-of-principle forensic application of LuminoSiPM is provided, exploiting an origami chemiluminescent paper-based sensor for acetylcholinesterase inhibitors, showing high potential for this portable low-cost device for on-site applications with adequate sensitivity for detecting low light intensities in critical fields.

Analytical performance comparisons of Modiϐied Jaffe’s kinetic method and Enzymatic Trinder method for creatinine along with risk zone identification

The aim of this study is to compare analytical performance characteristics and also the patient results obtained from both Modified Jaffe’s kinetic and Enzymatic Trinder methods for serum creatinine so as to identify risk zone, if present, within the measurement range. Serum creatinine was measured on 206 left-over serum samples by Modified Jaffe’s kinetic and Enzymatic Trinder methods. For analytical performance comparisons, limit of detection(LOD), limit of quantification(LOQ), linearity, measuring range, intra and inter-assay CV were measured and compared. Statistical comparisons were done by Pearson‘s correlation coefficient and Bland-Altman tests. For Enzymatic Trinder and Modified Jaffe’s kinetic methods, LODs for serum creatinine were 0.01 & 0.02 mg/dl respectively; LOQs were 0.04 & 0.06 mg/dl respectively; linearity were upto 55 mg/dl & 30 mg/dl respectively. Correlation coefficient was high (r=0.99); intra and inter-assay CV measurements were acceptable. However, CV was lower for Enzymatic Trinder method. Bland-Altman plot showed that more than 95% data points lie within ± 1.96 SD limit of mean difference value (0.16). Average discrepancy (ie. bias) was 0.16 mg/dl across whole measurement range. However, at low concentrations, Modified Jaffe’s kinetic method gave higher values indicating systematic bias, thereby forming a “risk zone” in measurement range. Analytical performance requirements were met by both methods for routine use and good agreement exists between them. However, better performance was not shown by Modified Jaffe’s kinetic method at low concentrations. Such a “risk zone” needs to be identified by laboratories for accurate reporting of creatinine results.

Rapid SARS-CoV-2 antigenic test: definition, legislation of use, technological principles, analytical and clinical performance comparison

The SARS-CoV-2 has emerged in China at the end of 2019. In order to meet the growing demand in laboratories for RT-PCR testing for viral genome detection, rapid tests detecting a SARS-CoV-2 protein (antigenic rapid test) have been developed. In this review, we present for different SARS-CoV-2 antigenic rapid tests authorized in France: legislation, technological principle, and analytical and clinical performances. Data bellow are those provided by the manufacturer/distributor. From the list of tests authorized by the French Ministry of Health, we have selected 25 for which the distributors/manufacturers have provided the technical data essential to their comparative analysis. The kits use immunochromatography technology, with detection of the nucleocapsid protein (n =24) or the spike protein (n =1). The matrix used is a nasopharyngeal (n =23), oropharyngeal (n =9) or nasal (n =3) swab. According to the test, the reading of the result is done from 15 to 30minutes after it is performed. The clinical sensitivity, for the more performant tests is conversely linked to the Ct of RT-PCR, ranging from 80.2% to 98.4%, according to the quantity of virus present in the sample. This percentage is inversely proportional to the Ct obtained using RT-PCR. The limit of detection ranges from 31.55 to 7200TCID50/mL. The clinical specificity, compared to a negative result of RT-PCR, is between 99.2% and 100%. Analytical specificity evaluated on other microorganisms is 100%, except for 3 kits that show cross-reactivities with SARS-CoV-1 (n =3) and MERS-CoV (n =1). Positive and negative predictive values range from 96.3% to 100% and 95% to 99.4%, respectively.

Comparison of analytical performance of the HbA1c assay on the fine care fluorescence immunochromatographic system.

Background: The Fluorescence Immunochromatographic method is a relatively new technique offering similar advantages to small clinical laboratories with the added value of reagents stability and increased precision. Here we aim to evaluate the Fluorescence Immunochromatographic method in terms of accuracy, precision, and linearity. Also, to compare its performance against the Bronate Affinity method. Methods: Reproducibility between the two methods was assessed by measuring ten prepared HbA1c reference materials with different concentrations. Additionally, the Bland-Altman Plot was also used to determine the comparability of measurements between the two methods within a 1.96 SD limit. Moreover, twenty repeated measurements of two HbA1c reference materials with different concentrations were carried out to assess accuracy and precision. Results: The “best fit values” after comparing ten measurements of the HbA1c reference materials between the two methods for the Slope of the linear regression model was 0.9764 ± 0.05566 with “Y” intercept of 0.5469 ± 0.4657, “X” intercept of -0.5601, and R2 of 0.9747. All ten results were inside the 1.96 limit of the Bland-Altman Plot. Similarly, comparison of two sets of HbA1c references materials, “Control N” and “Control P”, after twenty repeated analysis showed a Coefficient of Variation (CV) of 2.64% and 3.55% respectively. Conclusion: There is no significant difference between the two methods in detecting HbA1c. Method evaluation employing both a liner regression model of analysis as well as the Bland-Altman method showed no significant variance. This shows that the Fluorescent Immunochromatography instrument is suitable for detecting HbA1c in the clinically significant detection range.

Evaluation of the Succeeder SF-8200 Fully Automated Coagulation Analyzer.

The SF-8200 is a new coagulation analyzer developed by Beijing Succeeder Technology Inc., China. The SF-8200 is able to perform clotting, chromogenic, and immunoturbidimetric tests. System capability is a throughput of up to 360 tests per hour, 60 sample tubes can be loaded at any time, and its reaction cuvette capacity is 1,000. The analyzer also has an optional cap piercing module to reduce manual sampling time. We aimed to perform an analytical performance comparison study between Succeeder SF-8200 and Stago Compact Max3 because fully automated coagulation analyzers have become one of the most essential components of clinical laboratories. Routine coagulation tests were assessed, which are the most ordered in laboratories such as PT, aPTT, and fibrinogen. Stago Compact Max-3 was accepted as the reference instrument in the comparison study. The assay precisions were assessed using fresh and pooled plasma samples or consumer internal quality controls. Hemolysis, lipemia, and icterus interferences were also verified. The coefficients of variation assessed in the intra and inter-assay precision analyses were below 5% representatively for assessed parameters. The inter-analyser comparison demonstrated good results. Results obtained by the SF-8200 showed high comparability predominantly to used reference analyzers, with correlation coefficients ranging from 0.953 to 0.976. In our routine laboratory setting, SF-8200 reached a sample throughput rate of 360 tests per hour. No considerable influence on tests was found for elevated levels of free hemoglobin, bilirubin, or triglycerides. In conclusion, the SF-8200 was an accurate, precise, and reliable coagulation analyzer in routine testing. According to our study, the results demonstrated excellent technical and analytical performance.

Double-Stranded DNA Matrix for Photosensitization Switching

Photosensitization, originated from the activation of triplet states, is the basis of many photodynamic applications, but often competes with a series of nonradiative processes. Herein, we communic...

Analytical performance and method comparison of a quantitative point-of-care immunoassay for measurement of bile acids in cats and dogs.

Point-of-care analyzers (POCAs) for quantitative assessment of bile acids (BAs) are scarce in veterinary medicine. We evaluated the Fuji Dri-Chem Immuno AU10V analyzer and v-BA test kit (Fujifilm) for detection of feline and canine total serum BA concentration. Results were compared with a 5th-generation assay as reference method and a 3rd-generation assay, both run on a bench-top analyzer. Analytical performance was assessed at 3 different concentration ranges, and with interferences. For method comparison, samples of 60 healthy and diseased cats and 64 dogs were included. Linearity was demonstrated for a BA concentration up to 130 µmol/L in cats (r = 0.99) and 110 µmol/L in dogs (r = 0.99). The analyzer showed high precision near the lower limit of quantification of 2 µmol/L reported by the manufacturer. Intra- and inter-assay coefficients of variation were < 5% for both species and all concentrations. Interferences were observed for bilirubin (800 mg/L) and lipid (4 g/L). There was excellent correlation with the reference method for feline (rs = 0.98) and canine samples (rs = 0.97), with proportional biases of 6.7% and −1.3%, respectively. However, a large bias (44.1%) was noted when the POCA was compared to the 3rd-generation assay. Total observed error was less than total allowable error at the 3 concentrations. The POCA reliably detected feline and canine BA in clinically relevant concentrations.

The comparison of analytical performances of Mindray CL-1000i and Beckman Coulter Access II Troponin I methods in the light of recent guidelines and the quality requirements.

BackgroundThe results of cardiac troponin I (cTnI) methods used in the diagnosis of acute myocardial infarction (AMI) are highly variable. In this study, it was aimed to compare the analytical performance of the Mindray CL-series TnI method with the Beckman Coulter-Access II AccuTnI+3 method.MethodsAnalytical performance and method comparison experiments for cTnI measurement with Mindray CL-1000i and Beckman Coulter-Access II instruments were with the Clinical and Laboratory Standards Institute (CLSI) documents EP15-A3 and EP9-A3. Precision studies were performed with commercially available third-party quality control (QC) materials. Method comparison experiments were performed by using patient samples. Furthermore, the limit of quantification (LoQ), total analytical error (TAE), and sigma metrics of both methods was determined.ResultsThe repeatability CV% for the three levels of Mindray CL-series TnI were 1.86, 1.75, and 1.08, while within the laboratory, CV% values were 3.36, 5.27, and 5.82. The quantification limits for Mindray CL-series and Beckman AccuTnI+3 were found to be 0.0085 and 0.0366 ng/mL with a CV level of less than 10%, respectively. The Mindray CL-series TnI results in the method comparison study were higher compared to the Beckman Coulter Access II AccuTnI+3 method.ConclusionsWith low repeatability, low bias, and low LoQ, The Mindray CL-series cTnI method shows it may be used safely in its category. The significant difference between the two methods in the method comparison study reveals cTnI methods in the market should be standardized to ensure global traceability.

Targeted-Sequencing Workflows for Comprehensive Drug Resistance Profiling of Mycobacterium tuberculosis Cultures Using Two Commercial Sequencing Platforms: Comparison of Analytical and Diagnostic Performance, Turnaround Time, and Cost.

The emergence of Mycobacterium tuberculosis with complex drug resistance profiles necessitates a rapid and comprehensive drug susceptibility test for guidance of patient treatment. We developed two targeted-sequencing workflows based on Illumina MiSeq and Nanopore MinION for the prediction of drug resistance in M. tuberculosis toward 12 antibiotics. A total of 163 M. tuberculosis isolates collected from Hong Kong and Ethiopia were subjected to a multiplex PCR for simultaneous amplification of 19 drug resistance-associated genetic regions. The amplicons were then barcoded and sequenced in parallel on MiSeq and MinION in respective batch sizes of 24 and 12 samples. A web-based bioinformatics pipeline, BacterioChek-TB, was developed to translate the raw datasets into clinician-friendly reports. Both platforms successfully sequenced all samples with mean read depths of 1,127× and 1,649×, respectively. The variant calling by MiSeq and MinION could achieve 100% agreement if variants with an allele frequency of <40% reported by MinION were excluded. Both workflows achieved a mean clinical sensitivity of 94.8% and clinical specificity of 98.0% when compared with phenotypic drug susceptibility test (pDST). Turnaround times for the MiSeq and MinION workflows were 38 and 15 h, facilitating the delivery of treatment guidance at least 17-18 days earlier than pDST, respectively. The higher cost per sample on the MinION platform ($71.56) versus the MiSeq platform ($67.83) was attributed to differences in batching capabilities. Our study demonstrates the interchangeability of MiSeq and MinION platforms for generation of accurate and actionable results for the treatment of tuberculosis.

Recent Achievements and Current Interests in Research on the Characterization and Quality Control of Biopharmaceuticals in Japan

As reported in the previous commentary (Ishii-Watabe et al., J Pharm Sci 2017), the Japanese biopharmaceutical research group is promoting collaborative multilaboratory studies to evaluate and standardize new methodologies for biopharmaceutical characterization and quality control. We have conducted the studies and held 2 annual meetings in 2018 and 2019. At the 2018 meeting, Dr. Rukman DeSilva of the U.S. Food and Drug Administration and Dr. Srivalli Telikepalli of the National Institute of Standards and Technology participated as guest speakers. At the 2019 meeting, we invited Prof. John Carpenter of the University of Colorado, Prof. Gerhard Winter and Prof. Wolfgang Friess of Ludwig Maximilian University of Munich, and Dr. Tim Menzen of Coriolis Pharma Research, as guest commentators. In both meetings, the main research topic was strategies for the characterization and control of protein aggregates/subvisible particles in drug products. Specifically, the use of the light obscuration method for insoluble particulate matter testing with reduced injection volumes, and a comparison of analytical performance between flow imaging and light obscuration were discussed. Other topics addressed included host cell protein analysis, bioassay, and quality control strategies. In this commentary, the recent achievements of the research group, meeting discussions, and future perspectives are summarized.

Analytical and clinical performance evaluation and comparison of automated urinalysis analyzers

This study has investigated whether high levels of Reticulocytes-C4d (R-C4d) and Platelets-C4d (P-C4d) reflecting recent activity in SLE patients are correlated with changes in natural anticoagulation components, coagulation activation and endothelial injury markers.This study included three groups: 1) healthy women (control, n = 30); 2) women with low activity of the disease (SLEDAI 2 K ≤ 4, n = 30); 3) women with active disease (moderate or high activity) (SLEDAI 2 K > 4, n = 30). Median fluorescence intensity (MFI) of R-C4d and P-C4d were determined by flow cytometry using double labeling with specific monoclonal antibodies. Endothelial injury and hypercoagulability were evaluated by measuring Thrombomodulin and D-dimer levels.Higher MFI index of R-C4d were related to the recent activity of SLE, and higher expression of P-C4d indicated an elevated risk of thrombotic complications. Increased levels of soluble thrombomodulin and D-dimer were observed in patients with active SLE.R-C4d is helpful to monitor early disease activity and PC4-d may be an important tool to detect a prothrombotic phenotype in SLE. Elevated levels of D-dimer and thrombomodulin add value to P-C4d data and corroborate a hypercoagulable profile in women with SLE, contributing to an increased prothrombotic risk associated with inflammation.

Analytical performance and method comparison of the Elecsys® active B12 electrochemiluminescence immunoassay

Analytical performance and method comparison of the Elecsys® active B12 electrochemiluminescence immunoassay

Comparison of analytical performance of i-Smart 300 and pHOx ultra for the accurate determination of pleural fluid pH

BackgroundPleural fluid pH is an essential test for diagnosing complicated parapneumonic effusion. We evaluated the performance of two blood gas analyzers in measuring pleural fluid pH. MethodsThe i-STAT G3+ (Abbott) was used as a reference analyzer to evaluate the pH values obtained from other methods: the i-Smart 300 (i-SENS), the pHOx Ultra (Nova Biomedical), using a clot catcher to filter off microclot, and pH indicator paper. Within-device precision was performed using quality control materials. We compared pleural fluid pH (n = 86) by the above methods and analyzed the concordance rate at the level of the medical decision point, pH 7.2. ResultsThe within-device coefficient of variations of pH were below 0.1% for all blood gas analyzers tested. The slopes of the regression equations for the i-Smart 300, pHOx Ultra, and pH indicator paper against the reference analyzer were 0.850 (95% confidence interval, CI, 0.800–0.896), 0.714 (95% CI, 0.671–0.766), and 1.105 (95% CI, 0.781–1.581), respectively. The kappa values for the i-Smart 300, pHOx Ultra, and pH indicator paper against the reference analyzer were 0.883 (95% CI, 0.656–1.110), 0.739 (95% CI, 0.393–1.084), and 0.464 (95% CI, 0.102–0.826), respectively. ConclusionsThe i-Smart 300 and pHOx Ultra demonstrated good analytical performance and diagnostic accuracy when determining pleural fluid pH compared with that by the i-STAT G3+, whereas the pH indicator paper showed unsatisfactory results.