Clinical Chemistry Analyzer Research Articles

Patient-Centric Quantitative Microsampling for Accurate Determination of Urine Albumin to Creatinine Ratio (UACR) in a Clinical Setting.

Developing and implementing new patient-centric strategies for drug trials lowers the barrier to participation for some patients by reducing the need to travel to research sites. In early chronic kidney disease (CKD) trials, albuminuria is the key measure for determining treatment effect prior to pivotal kidney outcome trials. To facilitate albuminuria sample collection outside of a clinical research site, we developed 2 quantitative microsampling methods to determine the urinary albumin to creatinine ratio (UACR). Readout was performed by LC-MS/MS. For the Mitra device the within-batch precision (CV%) was 2.8% to 4.6% and the between-batch precision was 5.3% to 6.1%. Corresponding data for the Capitainer device were 4.0% to 8.6% and 6.7% to 9.0%, respectively. The storage stability at room temperature for 3 weeks was 98% to 103% for both devices. The recovery for the Mitra and Capitainer devices was 104% (SD 7.0%) and 95 (SD 7.4%), respectively. The inter-assay comparison of UACR assessment generated results that were indistinguishable regardless of microsampling technique. The accuracy based on LC-MS/MS vs analysis of neat urine using a clinical chemistry analyzer was assessed in a clinical setting, resulting in 102 ± 8.0% for the Mitra device and 95 ± 10.0% for the Capitainer device. Both UACR microsampling measurements exhibit excellent accuracy and precision compared to a clinical chemistry analyzer using neat urine. We applied our patient-centric sampling strategy to subjects with heart failure in a clinical setting. Precise UACR measurements using quantitative microsampling at home would be beneficial in clinical drug development for kidney therapies.

Monocyte to HDL Cholesterol Ratio (MHR) and Monocyte to Lymphocyte Ratio (MLR) in Overweight and Obese Women

Background: The prevalence of obesity and overweight in Indonesian women will continue to increase. Obesity and overweight conditions are often associated with low-grade inflammatory conditions and metabolic syndrome. The ratio of monocytes to HDL cholesterol (RMH) and the ratio of monocytes to lymphocytes (RML) are easy tests to monitor inflammation associated with increased body mass index and cardiovascular disorders due to metabolic syndrome. Objective: To analyze the differences in RMH and RML in obese and overweight women. Methods: The cross-sectional study was conducted in the outpatient laboratory at the Diponegoro National Hospital (RSND). This study included 55 overweight women (BMI 25.00 – 29.99 kg/m2) and 55 obese women (BMI ≥ 30 kg/m2), healthy, aged 25-45 years. Research subjects were excluded with the criteria of not having hypertension, liver disorders, and diabetes mellitus. RMH is obtained by dividing the absolute monocyte count by HDL cholesterol. RML is obtained by dividing the absolute monocyte and lymphocyte counts. Monocyte and lymphocyte numbers were obtained by examining a Complete Blood Count (CBC) using an automatic hematology analyzer. HDL cholesterol levels were measured by enzymatic methods using a clinical chemistry analyzer. Statistical analysis with the Mann-Whitney test. Results: There is a difference in RMH between obese and overweight women (p = 0.003). There was no difference in RML (p = 0.342) between the two groups. Conclusion: Obese women have a significantly higher RMH than overweight. RMH can be used as an assessment of inflammatory conditions and is used as a clinical alert for various health problems in obese and overweight women

A Comparative Analysis between HaemurEx (Clinical Chemistry Analyzer) and Standard Methodologies for Determining Its Efficacy for Estimation of Various Blood Parameters Like Glucose, Cholesterol, Triglyceride, Creatinine, Direct Bilirubin, and Total Bilirubin

A Comparative Analysis between HaemurEx (Clinical Chemistry Analyzer) and Standard Methodologies for Determining Its Efficacy for Estimation of Various Blood Parameters Like Glucose, Cholesterol, Triglyceride, Creatinine, Direct Bilirubin, and Total Bilirubin

Recent Advances in Acoustofluidics for Point-of-Care Testing.

Point-of-care testing (POCT) has played important role in clinical diagnostics, environmental assessment, chemical and biological analyses, and food and chemical processing due to its faster turnaround compared to laboratory testing. Dedicated manipulations of solutions or particles are generally required to develop POCT technologies that achieve a "sample-in-answer-out" operation. With the development of micro- and nanotechnology, many tools have been developed for sample preparation, on-site analysis and solution manipulations (mixing, pumping, valving, etc.). Among these approaches, the use of acoustic waves to manipulate fluids and particles (named acoustofluidics) has been applied in many researches. This review focuses on the recent developments in acoustofluidics for POCT. It starts with the fundamentals of different acoustic manipulation techniques and then lists some of representative examples to highlight each method in practical POC applications. Looking toward the future, a compact, portable, highly integrated, low power, and biocompatible technique is anticipated to simultaneously achieve precise manipulation of small targets and multimodal manipulation in POC applications.

Determination of the Accuracy of Quantitative Measurement Methods in the Clinical Chemistry Laboratory at Machakos Level V Hospital, Kenya

Accuracy is the extent to which measurements are closely related to the actual values of the analyte. Accuracy is one of the key requirements in Laboratory method verification. Verification is a method of ensuring that tests are carried out per the manufacturer's specifications when tested by laboratory staff and patients at the facility. Other elements of verification include precision, linearity verified with reportable range, uncertainty of measurement, carry-over studies, reference ranges and limit of detection. This study aims to determine the accuracy of the quantitative measurement methods in the Clinical Chemistry laboratory in the month of January 2023. It also provides an alternative method for meeting accreditation requirements on accuracy by medical laboratories seeking accreditation in far-stretched laboratories where interlaboratory comparison may not be feasible. A systematic review and meta-analysis at Machakos County, Kenya. The procedure involved analysing commercially available internal quality control material five (5) times a day for eight (8) days bearing the same lot number. Roche Diagnostics, Mannheim, Germany supplied all the reagents, internal quality control materials and calibrators. Accuracy was determined using Roche Cobas® Intergra 400 Clinical Chemistry analyser to perform a comparative descriptive analysis of albumin, alanine aminotransferase (ALT), alkaline phosphatase (Alk Phos), aspartate aminotransferase (AST), chloride, creatinine, Direct Bilirubin (D. Bil), Gamma-glutamyl transferase (GGT), potassium, sodium, total bilirubin, total protein, and urea. The study followed guidelines issued by the Clinical Laboratory Improvements Amendment 1988 (CLIA) and Clinical Laboratory Standards Institute (2014). Data analysis was carried out using Excel Windows 10 MS Office 2021. Mean, standard deviation (SD), Z-score, bias %, coefficient of variation (CV) %, and total error allowable (Tea) were calculated from the results of measurement of the analytes. All the analytes achieved a mean which fell within the manufacturer verification interval and hence passed. The bias % score for the analytes was as follows 5 analytes level (19.2%) scored 0 - ±1, 10 analytes level (38.5%) scored ±1.1 - ±2, 7 analytes level (26.9%) ±2.1 - ±3 and 4 analytes level (15.4%) scored above ±3. All analytes were found to have an excellent Z-score performance between 0 to ± 1.96. The total error allowable was found to fall within CLIA and CLSI specifications limits except for chloride PCC1/ Normal control which failed at 5.82% (CLIA target being ± 5%). Analytes' mean was expected to fall within the given manufacturer's mean. The bias % for the analytes which was at zero or near ± zero was considered an excellent score the further away the score was, the poorer the performance. The Z-score was also calculated to establish how far the observed mean fell from the target mean. All analytes were found to have an excellent Z-score performance between 0 to ± 1.96. A Z-score of ± 1.96 to ± 2.57 indicates good performance while a Z-score of over ± 2.58 indicates failed performance. These good results are attributable to the fact that analysis was carried out within a very short duration by the same person, on the state-of-the-art instrument, in a well-controlled environment hence no room for analytical variation. Chloride being an electrolyte failed since it is physiologically controlled in a strict and narrow range.

BMP2 gene transfer induces pericardial effusion and inflammatory response in the ischemic porcine myocardium.

Pro-angiogenic gene therapy is being developed to treat coronary artery disease (CAD). We recently showed that bone morphogenetic protein 2 (BMP2) and vascular endothelial growth factor-A synergistically regulate endothelial cell sprouting in vitro. BMP2 was also shown to induce endocardial angiogenesis in neonatal mice post-myocardial infarction. In this study, we investigated the potential of BMP2 gene transfer to improve cardiomyocyte function and neovessel formation in a pig chronic myocardial infarction model. Ischemia was induced in domestic pigs by placing a bottleneck stent in the proximal part of the left anterior descending artery 14 days before gene transfer. Intramyocardial gene transfers with adenovirus vectors (1 × 1012 viral particles/pig) containing either human BMP2 (AdBMP2) or beta-galactosidase (AdLacZ) control gene were performed using a needle injection catheter. BMP2 transgene expression in the myocardium was detected with immunofluorescence staining in the gene transfer area 6 days after AdBMP2 administration. BMP2 gene transfer did not induce angiogenesis or cardiomyocyte proliferation in the ischemic pig myocardium as determined by the quantitations of CD31 or Ki-67 stainings, respectively. Accordingly, no changes in heart contractility were detected in left ventricular ejection fraction and strain measurements. However, BMP2 gene transfer induced pericardial effusion (AdBMP2: 9.41 ± 3.17 mm; AdLacZ: 3.07 ± 1.33 mm) that was measured by echocardiography. Furthermore, an increase in the number of immune cells and CD3+ T cells was found in the BMP2 gene transfer area. No changes were detected in the clinical chemistry analysis of pig serum or histology of the major organs, implicating that the gene transfer did not induce general toxicity, myocardial injury, or off-target effects. Finally, the levels of fibrosis and cardiomyocyte apoptosis detected by Sirius red or caspase 3 stainings, respectively, remained unaltered between the groups. Our results demonstrate that BMP2 gene transfer causes inflammatory changes and pericardial effusion in the adult ischemic myocardium, which thus does not support its therapeutic use in chronic CAD.

Changes in liver metabolic pathways demonstrate efficacy of the combined dietary and microbial therapeutic intervention in MASLD mouse model

ObjectiveMetabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is the most prevalent liver disease globally, yet no therapies are approved. The effects of Escherichia coli Nissle 1917 expressing aldafermin, an engineered analog of the intestinal hormone FGF19, in combination with dietary change were investigated as a potential treatment for MASLD. MethodsMASLD was induced in C57BL/6J male mice by American lifestyle-induced obesity syndrome diet and then switched to a standard chow diet for seven weeks. In addition to the dietary change, the intervention group received genetically engineered E. coli Nissle expressing aldafermin, while control groups received either E. coli Nissle vehicle or no treatment. MASLD-related plasma biomarkers were measured using an automated clinical chemistry analyzer. The liver steatosis was assessed by histology and bioimaging analysis using Fiji (ImageJ) software. The effects of the intervention in the liver were also evaluated by RNA sequencing and liquid-chromatography-based non-targeted metabolomics analysis. Pathway enrichment studies were conducted by integrating the differentially expressed genes from the transcriptomics findings with the metabolites from the metabolomics results using Ingenuity pathway analysis. ResultsAfter the intervention, E. coli Nissle expressing aldafermin along with dietary changes reduced body weight, liver steatosis, plasma aspartate aminotransferase, and plasma cholesterol levels compared to the two control groups. The integration of transcriptomics with non-targeted metabolomics analysis revealed the downregulation of amino acid metabolism and related receptor signaling pathways potentially implicated in the reduction of hepatic steatosis and insulin resistance. Moreover, the downregulation of pathways linked to lipid metabolism and changes in amino acid-related pathways suggested an overall reduction of oxidative stress in the liver. ConclusionsThese data support the potential for using engineered microbial therapeutics in combination with dietary changes for managing MASLD.

Insight into the negative effect and lipid profile alterations in liver of mice exposed to methylimidazolium ionic liquids, a novel "green" solvent.

Ionic liquids (ILs) have been recognized as potential environmentally friendly solvents; however, their potential toxicity to living organisms warrants thorough investigation, particularly for novel-generation ILs in mammalian models. In this study, we examined the hepatic effects and disruption of lipid metabolism in mice exposed to 1-heptyl-3-methylimidazolium chloride (C7[MIM]Cl), a novel ILs. After four weeks of oral administration at different dosages (2.38, 5.95, and 11.9mg/kg b.w.), we conducted clinical chemistry analysis and histopathological examination of the liver to assess biochemical and structural changes. The low-dose C7[MIM]Cl group exhibited a significant increase in alanine aminotransferase (ALT) levels, while aspartate aminotransferase (AST) levels were elevated in both low-dose and high-dose groups without statistical significance. Histopathological examination showed inflammatory cell infiltration and red blood cell aggregation in the livers of mice exposed to C7[MIM]Cl, particularly in the high-dose group. Oxidative stress levels showed moderate changes in response to C7[MIM]Cl exposure. Notably, hepatic biochemical parameters revealed a dose-dependent increase in triglycerides (TG) levels with statistically significant differences compared to the control group (P≤0.01). Targeted lipidomic analysis revealed notable alterations in liver lipids of mice exposed to C7[MIM]Cl, with lysophosphatidylethanolamine (18:0), phosphatidylcholines (18:0), and phosphatidylcholines (19:0) identified as critical lipids associated with C7[MIM]Cl exposure. Furthermore, metabolic pathway analyses demonstrated significant disturbances in the glycerophospholipid metabolic pathway. These findings provide valuable insights into the hepatic effects of C7[MIM]Cl exposure and novel perspectives on the disruption of lipid metabolism underlying ILs toxicity.

A-072 An All-Purpose Particle Enhanced Immunoturbidimetric Assay for the Comparable, Instrument-Independent Monitoring of Procalcitonin in the Management of Sepsis

Abstract Introduction Sepsis is a life-threatening organ dysfunction caused by a dysregulated host immune response to infection. It is a global health concern and a leading cause of death worldwide, affecting an estimate of 48.9 million people every year. Procalcitonin (PCT) revealed to be an indispensable parameter for the management of sepsis. However, recent analysis of EQA survey results suggested crucial deviations of PCT measurements in Germany and studies by the IFCC Working Group on standardization of PCT stated the need for a higher-order reference measurement procedure.Here we present the evaluation of the all-purpose particle enhanced immunoturbidimetric assay (PETIA) of DiaSys, which can be easily applied to every high-throughput clinical chemistry analyzer. The high diversity of applications and datasets match current diagnostic and regulative needs (IVDR). Procalcitonin FS enables the equivalent and instrument-independent monitoring of PCT in the management of sepsis. Methodology Evaluation of Procalcitonin FS was performed on seven clinical chemistry analyzer platforms (Jeol BioMajesty® JCA-BM6010/C, DiaSys respons®920 and respons®940, Roche cobas c501, Abbott Architect c8000 and Alinity c, Beckman Olympus AU680). Measurements were performed according to Clinical and Laboratory Standards Institute (CLSI) protocols. Results The onboard stability reaches 8 weeks (with chimney) on BioMajesty® JCA-BM6010/C, 20 days on respons®920 and respons®940, 21 weeks on cobas c501, 9 weeks on Architect, 12 weeks on Olympus AU680 and 13 weeks on Alinity c. The calibration stability is 4 weeks (with chimney) on BioMajesty® JCA-BM6010/C, 2 weeks (with chimney) on respons®920 and respons®940, 21 weeks on cobas c501, 3 weeks on Architect, 5 weeks on Olympus AU680 and 10 weeks on Alinity c. The intra-assay precision (CV%) ranges from ≤4.57% on respons®920 up to ≤7.19% on respons®940. The Total Precision (CV%) ranges from ≤3.99% on cobas c501 up to ≤9.62% on Olympus AU680. LOB ranges from 0.07 ng/mL on BioMajesty® JCA-BM6010/C up to 0.130 ng/mL on Olympus AU680. LOQ ranges from 0.20 ng/mL on Architect up to 0.277 ng/mL on Olympus AU680. The reagent displayed a linear recovery up to 50 ng/mL and no prozone effect was detected up to 1000 ng/mL on all seven analyzers. The Passing & Bablok regression vs the reference test showed an excellent comparability/alignment between the methods (slope ≤1.11, intercept ≤0.156 ng/mL, R ≥ 0.986). Conclusion Evaluation work proves that DiaSys PETIA reagent Procalcitonin FS shows excellent performance on all seven clinical chemistry analyzers. In addition, the high comparability between the seven analyzers enables the reliable and instrument-independent monitoring of PCT in the management of sepsis, and thus offering a solution to the current landscape of deviating PCT measurement results.

A-085 Analytical Performance of BÜHLMANN sCAL® turbo, a New, Reliable and Precise High-Throughput Assay to Assess the Inflammatory Status of Patients

Abstract Background Serum calprotectin plays an important pro-inflammatory role in the innate immune system and is a promising marker with several potential applications in rheumatoid arthritis, juvenile idiopathic arthritis and systemic onset juvenile idiopathic arthritis. Serum calprotectin can be a useful tool to monitor disease activity and predict treatment response in these patients. Methods The aim of this work was to evaluate the analytical performance of BÜHLMANN sCAL® turbo, a new turbidimetric test on clinical chemistry analyzers for the determination of calprotectin levels in serum. Assay characteristics were established according to CLSI guidelines (CLSI C28-A3, EP05-A3, EP07-A3, and EP09-A3). 111 samples were measured using 3 lots over 3 days and compared to another commercially available assay. Results The analytical measuring range from 0.23 to 15 µg/mL, extended to 225 µg/mL with an additional dilution in an automated rerun on a clinical chemistry analyzer, is suitable to address the described pathologies. 160 self-declared healthy adults (m/w) aged 18–83 years exhibit reference limits of 1.77 and 1.10 µg/mL when sampled either in a native tube or a gel separator tube and processed within 3.4 h after collection, respectively. With a within-laboratory precision up to 5.1% and a reproducibility up to 11.1% the method is precise, reliable and suitable for routine use. Tested concentrations of oral and injectable pharmaceuticals showed no interference. Hemolyzed samples are not recommended. It shows good comparison to an existing commercial assay with a bias of 12.5% (Bland-Altman) and a slope of 1.16 (Passing-Bablok). Conclusion A high-throughput test on clinical chemistry analyzers is now available with the turbidimetric BÜHLMANN sCAL® turbo allowing reliable and precise measurements of serum calprotectin levels.

A-375 Evaluation of the CLIA-Waived Afinion HbA1c Point-of-Care Test

Abstract Background Point-of-care (POC) HbA1c tests can be essential in evaluation/monitoring of diabetes provided that the test has acceptable analytical performance. The Abbott Afinion HbA1c is an in vitro diagnostic test for quantification of HbA1c in human capillary and venous whole blood. This study aim was to evaluate the performance of Afinion HbA1c in whole blood EDTA patient samples. Methods The Afinion utilizes the boronate affinity principle for measurement of HbA1c. Hemoglobin A1c was tested on the Abbott AfinionTM 2 analyzer. Two levels of quality control (QC) and two levels of whole blood EDTA patient samples (one low and on high) were used to assess imprecision. Within-day precision was determined by assaying the 20 times in one day and between-day precision was determined by assaying the samples in duplicates over a period of 10 days. The analytical measured range (AMR) and method comparison was performed by using whole blood EDTA patient samples. Percent bias plot and Deming regression analysis was performed by EP Evaluator. Results Within-day and between-day precision and accuracy data are summarized in table 1 below. The assay displayed good linearity over the measured AMR. Lastly, the method comparison between Afinion vs Cobas pro, had a correlation coefficient R2 of 0.994, slope (m) of 1.14 and % bias was 2.5%. Afinion vs Trinity Biotech HPLC had R2 = 0.996, m = 1.04 and % bias was −2.3%. Afinion vs DCA Vantage had R2 = 0.991, m = 1.03 and % bias 1.5. Conclusion We conclude that the Abbott Afinion POC device evaluated here is precise and yields results consistent with other Clinical Chemistry analyzers such as Cobas Pro and Trinity Biotech.

B-330 Homogeneous Enzyme Immunoassay for Hydrocodone

Abstract Background Hydrocodone is a semi-synthetic derivative of codeine and produces opioid-like effects similar to morphine. Hydrocodone (Trade names: Vicodin, Lortab, Hycodan, Vicoprofen) is one of the most frequently prescribed opioids in the U.S. as an antitussive (cough suppressant) and narcotic analgesic agent for the treatment of moderate to severe pain. Its ease of prescription and opioid-like effects has led to widespread drug diversion and abuse. The two commercially available homogeneous immunoassays for the detection of hydrocodone in urine at a cutoff of 300 ng/mL suffer undesirable cross-reactivity to oxycodone and morphine at concentrations below 25 000 ng/mL. ARK Diagnostics has developed the ARK Hydrocodone Assay to detect hydrocodone at a cutoff of 300 ng/mL with no cross-reactivity to oxycodone, morphine, and codeine at concentrations below 100 000 ng/mL. Methods The ARK™ Hydrocodone Assay is a liquid stable homogeneous enzyme immunoassay, consisting of two reagents, with a cutoff of 300 ng/mL and semi-quantitative range up to 800 ng/mL. The performance of this assay was evaluated on the Beckman Coulter AU680 Automated Clinical Chemistry Analyzer. Precision, spiked recovery, specificity, Histogram Overlap Analysis of ±25% controls and the cutoff, and method comparison with LC-MS/MS were evaluated. Results In semi-quantitative mode, total precision ranged from 3.9% to 9.9%CV. Spiked recovery of hydrocodone ranged from 86.2% (720 ng/mL) to 102.9% (240 ng/mL). The active metabolite, hydromorphone, showed an approximate equivalence to the 300 ng/mL hydrocodone cutoff at 299 ng/mL (100.3% cross-reactivity). Histogram overlap analysis showed no overlap between cutoff and control levels. Method correlation with LC-MS/MS using authentic urine samples showed an excellent agreement with a specificity of 100% and sensitivity of 96.9% (98 positives and 128 negatives). Conclusion The ARKTM Hydrocodone Assay measures hydrocodone and its metabolite hydromorphone in human urine with acceptable performance. The assay is sensitive, rapid, and applicable to a wide range of clinical chemistry analyzers.

The CELTIC ranges project (comprehensive and effective laboratory test reference intervals for Irish children) methodology and results for renal profile tests in plasma on the Roche modularTM system.

The CELTIC ranges project aims to deliver a comprehensive range of reference intervals for commonly ordered laboratory investigations suitable for use in an Irish population as well as enabling comparison with relevant international studies. In this paper, we describe our methodology used throughout the entire project and present paediatric reference intervals for renal profile tests in plasma (sodium, potassium, urea and creatinine). 1023 children aged up to 17years were recruited from our hospital's general practitioner paediatric phlebotomy clinic. Clinical chemistry analyses were performed on the Roche modular system and statistical analysis was completed in line with CLSI guideline EP28-A3c. The plasma reference interval for sodium for ages 0.45-16.99 years was 137-143mmol/L in 1000 subjects (combined genders). For plasma potassium, the corresponding ranges between 1 and 16.99years (combined genders) were 3.6-4.8mmol/L. Apart from neonates and in keeping with other studies, age partitioning for electrolytes was not required. Data for plasma creatinine (enzymatic methodology) and urea is also presented and, as anticipated, required partitioning for both age and gender. Our renal profile findings are broadly consistent with those of international studies, for example, CALIPER, HAPPI, NORDIC, PRINCE and KiGGs. Moreover, the CELTIC ranges study is also based on over 1000 subjects whose samples were analysed on the widely used Roche modular analytics system. We also expect the findings will improve knowledge of children's metabolic health in Ireland.

B-125 Artificial Intelligence Application to Improve the Algorithm for Autoverification of Results of Biochemical Markers that Assess Thyroid Function

Abstract Background The results verification process is the most important control step of the post-analytical phase. It can be done in two ways, manually by a professional, or using autoverification systems. Appropriate results are verified and submitted to the Laboratory Information System (LIS). Corrective actions are initiated for discordant results prior to their submission to the LIS. Autoverification is a process where the laboratory tests results are published without any professional’s intervention. It is recommended that each laboratory creates the necessary cut-off values for autoverification, according to its population and its biochemical-medical criteria. In our laboratory, an autoverification algorithm is applied to evaluate thyroid function, which involves the measurement of 2 parameters: Thyrotropin (TSH) and Free Thyroxine (FT4). These parameters were chosen because they are the most used for characterizing thyroid function. The autoverification algorithm was defined for euthyroid, hypothyroid and hyperthyroid patients. Our professionals proposed a “safe range” for both parameters and we relate those parameters results for autoverification. We study the usefulness of artificial intelligence models by clustering non-supervised machine learning algorithms, to find behavioral patterns of not autoverified sample results, to support and even broaden the “safe ranges” established by our professionals. The goal was to improve the current autoverification algorithm by using artificial intelligence for thyroid function test results and to increase the autoverification percentage. Methods The autoverification process was carried out at TURNER Laboratories, Rosario, Argentina. The autoverification algorithm was designed according to the Laboratory and Clinical Standards Institute Guide AUTO10-A. The Atellica Data Manager (ADM) middleware was used to provide the connection between the Atellica Solution Immunoassay & Clinical Chemistry Analyzers and the LIS. ADM receives the results from the analyzers and processes them in consideration of the pre-analytical (age, sex, etc.), analytical (QC, flags, etc.) and post-analytical (Delta Check, etc.) conditions. It then applies the autoverification algorithm to send the results to the LIS. In the first semester of 2022, we used the autoverification algorithm with the existing “safe ranges” in 18 626 samples of outpatients between the ages of 16 and 60. On the other hand, we applied different Clustering algorithms to the samples that were not autoverified, to find behavior patterns. The ones we used are: KMeans, Fuzzy C-Means, DBSCAN, Agglomerative Clustering, Dendrogram and Affinity Propagation. We chose KMeans with k = 4. Our professionals thoroughly analyzed each of the clusters and defined “new safe ranges” for autoverification. In the second semester of 2022, 18 947 samples were analyzed and the autoverification algorithm was applied with the “safe ranges” and the “new safe ranges”. Results In the first semester of 2022, by applying the existing “safe ranges” we obtained an autoverification of 19.0%. We then simulated an autoverification with “safe ranges” and “new safe ranges” and obtained an autoverification of 71.5%. In the second semester, we applied autoverification with “safe ranges” and “new safe ranges” obtaining an autoverification of 72.7%. Conclusion The application of machine learning algorithms has significantly improved the level of autoverification of biochemical markers that evaluate thyroid function.

B-120 Atellica® Ci 1900 Assay Sigma Metrics Evaluation

Abstract Background The Atellica® CI 1900 Analyzer is a stand-alone, integrated clinical chemistry and immunoassay analyzer. Offering the same assay portfolio as the Atellica® Solution, the Atellica® CI 1900 analyzer is designed to complement the Atellica® Solution in hub-and-spoke settings, enabling labs of every size to offer state-of-the-art patient testing. Six Sigma is synonymous with process performance, and Sigma metrics have become the analytical quality benchmark for the medical device industry. In this study, Sigma metrics were calculated for a total of 71 Atellica® assays to provide a simple, translatable value to evaluate a given assay’s performance on the Atellica® CI 1900 Analyzer. Methods Allowable total error (ATE) for each assay was defined from the Clinical Laboratory Improvement Amendment (CLIA) table. When an analyte was not present in the CLIA table, alternative sources were consulted, including the RiliBÄK table, Royal College of Pathologists of Australasia (RCPA) table, and Ricos Biological Variability. Precision studies were conducted in accordance with Clinical and Laboratory Standards Institute (CLSI) document EP05-A3 over 20 days (n = 80 replicates) using the Atellica® CI 1900 Analyzer. Method comparison studies conducted on the Atellica® CI and Atellica® CH/IM Analyzers, with at least 100 patient samples spanning the assay’s measuring interval in accordance with CLSI document EP09-A3, were used to establish bias at the selected target precision concentration. Sigma metrics were determined for each assay using the equation Sigma metric = (ATE – %bias)/(Within-lab %coefficient of variation [CV]). Results Sigma metrics were determined for a total of 71 Atellica® assays, resulting in 93% of assays performing above Five or Six Sigma and 0 assays performing below 4 Sigma. Of these, 44 of 52 clinical chemistry and 15 of 19 immunoassays performed above the 6 Sigma level. Conclusions Sigma metrics that provide a benchmark for laboratory quality classify over 90% of assays on the Atellica® CI 1900 Analyzer with scores of 5 or 6, corresponding to the classification of excellent or world-class performance. Therefore, laboratories can expect high quality assay performance with strong comparability between the Atellica® CI 1900 Analyzer and the Atellica® Solution. **Not available for sale in the US. Product availability varies by country.

B-133 Beckman Coulter’s DxC 500 AU Clinical Chemistry Analyzer, Assessed by Six Sigma Metrics, Meets and Exceeds the Demands of CLIA 2024 Performance Specifications

Abstract Background The analytical Sigma-metric is a quality assessment tool, derived from the well-known Six Sigma management approach, and has been employed in Clinical Chemistry Assay performance assessments for over two decades. The analytical Sigma-metric, for an analyte or test in the clinical laboratory, is calculated using three variables that are routinely available; imprecision (CV), inaccuracy (bias) and total allowable error (TEa), all expressed as percentages or all in units. A range of assays were assessed for Sigma-metric performance including ISE chemistries for urine and serum, IgG serum and CSF, CRP serum and Glucose serum, urine and CSF, on the Beckman Coulter DxC 500 AU. The Beckman Coulter DxC 500 AU clinical chemistry analyzer* is the latest system from Beckman Coulter. It is a fully automated, random-access analyzer, designed for low to medium volume laboratories, with a throughput of 800 tests/h including ISEs. Methods To assess the 6-sigma performance of the assays on the DxC 500 AU, the standard analytical equation was used; Sigma metric = (TEa-|Bias|)/CV. Precision data was generated following the CLSI EP05 guideline, utilizing the 20-day protocol with test samples at various levels tested twice a day with a minimum of 2 h between runs. Relative bias was determined through a method comparison study tested, following the CLSI EP09-A3 guideline, between the DxC 500 AU and the DxC 700 AU, and evaluated a minimum of 100 samples completed over a minimum of 3 days. Bias was calculated at various levels across the dynamic range utilizing both Passing-Bablok and Deming regression models. The 6-sigma performance was assessed against total error (TE) goals from various sources including the new CLIA 2024 performance criteria for serum, Royal College of Pathologists of Austral-Asia (RCPA) ALP for urine assays, and in one case, the Wisconsin State Lab of Hygiene (WSLH) goal for a CSF analyte. Results Urine applications for ISEs and Glucose all demonstrated >6-sigma performance. The glucose CSF demonstrated >5-sigma performance while the IgG CSF assay demonstrated >3-sigma performance. For the serum applications, all assays demonstrated >4-sigma performance, with CRP, glucose and chloride demonstrating >6-Sigma, IgG >4-sigma and potassium and sodium >5-sigma. Through the use of Westgard Sigma Rules, this indicates that most assays do not require extensive multi-rule monitoring, but instead can rely on fewer rules with wider control limits. Conclusion Excellent performance has been demonstrated for the assays evaluated, with all urine applications performing at >6-sigma and serum assay at >4-sigma, and CSF assays performing at >3-sigma. Sigma-metric analysis confirms the instrument will meet or exceed adherence to the coming, tighter CLIA 2024 performance specifications. Further, QC for these assays can be optimized to reduce the number of rules, levels, and runs implemented for routine monitoring. The resulting optimized process enables the laboratory to produce quality results efficiently with increased confidence for proper test interpretation. *Product In development. Pending clearance by the United States Food and Drug Administration and achievement of CE compliance. Not currently available for in vitro diagnostic use.

B-331 Homogeneous Enzyme Immunoassay for the Quantitative Determination of Methotrexate

Abstract Background Methotrexate (MTX), a classical antifolate, can be safely administered over a wide dose range as maintenance chemotherapy for acute lymphoblastic leukemia and treatment of nononcologic diseases including rheumatoid arthritis or psoriasis. When combined with leucovorin (LV) rescue, high-dose MTX (HDMTX; doses of 1000–33 000 mg/m2) is usually administered as a prolonged i.v. infusion for a variety of cancers, including acute lymphoblastic leukemia, lymphoma, osteosarcoma, breast cancer, and head and neck cancer. HDMTX can be safely administered to patients with normal renal function by vigorously hydrating and alkalinizing the patient to enhance the solubility of MTX in urine. Serum levels may reach 1000 μmol/L or more. Pharmacokinetically guided LV rescue by monitoring MTX serum levels is required to prevent potentially lethal MTX toxicity. Ability to measure MTX accurately at 0.050 μmol/L enables clinical determination of non-toxic status Methods The ARK™ Methotrexate II Assay is a homogeneous enzyme immunoassay for the quantitative determination of methotrexate in human serum or plasma on automated clinical chemistry analyzers. The assay was evaluated on the Beckman AU680 analyzer. The assay consists of two reagents, six-level calibrators, and six-level (0.070, 0.400, 0.800, 5.0, 50.0, 500.0 μmol/L) quality controls. Performance of the assay was determined by assessing precision, limit of quantitation, linearity, endogenous substances interference, high sample dilution (1:10 serial dilutions), on-board auto dilution (at 1:10 and 1:50), cross-reactivity, and method comparison. Results Within-lab precision (%CV) for control levels were 3.00% (0.070 µmol/L), 1.40% (0.400 µmol/L), 2.05% (0.800 µmol/L), 1.58% (5.0 µmol/L), 2.30% (50.0 µmol/L), and 1.62% (500.0 µmol/L). Limit of Detection and Quantitation: LoD was 0.004 µmol/L and LoQ was 0.030 µmol/L (4.87% CV, 113.6% analytical recovery). The ARK Methotrexate II Assay showed less than 8% deviation from linearity over the range 0.030 to 1.300 µmol/L. Endogenous substances did not interfere with measurement of MTX at the levels tested. High sample manual dilution (2.0, 20.0, 200.0, 1200.0, 5.0, 50.0, and 500.0 µmol/L) and on-board auto dilution (1:10 and 1:50) results were within 10% of nominal values. Cross-reactivity to compounds (potentially co-administered drugs, folate derivatives, and compounds of similar structure) tested was <10% interference. The major metabolite, 7-hydroxy MTX, at 50 µmol/L produced less than 10% interference for MTX levels of 0.050 and 0.500 µmol/L. Passing Bablok analysis of the results for 90 patient specimens of ARK MTX II Assay compared to liquid chromatography with tandem mass spectrometry (LC-MS/MS) was 1.03 + 0.00 (r2 = 0.98). Conclusion The ARK™ Methotrexate Assay II quantitated methotrexate accurately and precisely in serum and plasma. Performance on the Beckman AU680 automated clinical chemistry analyzer demonstrated excellent precision, recovery, and clinical accuracy vs LC-MS/MS.

A-070 A fully automated HbA1c Assay on the DxC 500 AU Clinical Chemistry Analyser

Abstract Background Diabetes mellitus is a condition characterized by hyperglycemia resulting from the body’s inability to use blood glucose for energy. In Type-1 diabetes, the pancreas no longer makes insulin and blood glucose cannot enter the cells to be used for energy. In Type-2 diabetes, the pancreas does not make enough insulin or the body is unable to use insulin correctly. According to the World Health Organization (WHO), 422 million adults were living with diabetes globally in 2014 with an estimated 1.6 million deaths directly associated with diabetes annually. HbA1c is the major species of glycohemoglobin in human blood. HbA1c formation occurs through a non-enzymatic reaction, called glycation, which occurs between glucose and the n-terminal valine of the hemoglobin â-chain of HbA. A Schiff base intermediate product is formed, which rearranges to form a stable ketoamine in an irreversible reaction. The rate of glycation is proportional to the glucose concentration in the bloodstream and is an accurate reflection of average blood glucose over a period of eight to twelve weeks. HbA1c testing is recommended for the diagnosis of diabetes by the International Expert Committee (IEC), the American Diabetes Association (ADA), and the WHO, who recommended a diagnostic threshold of = 6.5% ( = 48 mmoL/moL) HbA1c and a range for pre-diabetes of 5.7%–6.4% (39–46 mmoL/moL) HbA1c. Methods The HbA1c Advanced assay on the DxC 500 AU* utilizes automatic sample pre-treatment, has batch and random access capability. No manual pre-treatment of the whole blood sample or additional washing steps are required. Firstly the red blood cells are hemolyzed automatically, total hemoglobin and glycated hemoglobin are then measured colorimetrically and immunoturbidimetrically respectively. Results Precision studies were conducted according to CLSI EP15-A3. Commercial controls and four native K2 EDTA whole blood samples ranging from 5.1% to 12.0% HbA1c, were run twice daily, over twenty days using three lots of reagent on three DxC500AU Clinical Chemistry analyzers at a single site. Repeatability ranged from 0.86% to 1.44% CV and Total Precision ranged from 1.55% to 2.43% CV. Linearity studies were conducted according to CLSI EP06-A, and verified an analytical measuring range of 4.0%–15.0% (NGSP) and 20–140 mmol/mol (IFCC). Method comparison and bias estimation was evaluated using CLSI EP09-A3. K2 EDTA patient samples (n = 150) across the analytical range were run vs a Secondary Reference method and yielded a slope of 1.031, intercept −0.147% HbA1c, correlation coefficient R = 0.997 for Weighted Deming regression, and slope 1.000 and intercept 0.06% HbA1c for Passing Bablok regression. Interference studies carried out demonstrated no significant interference from common endogenous interferences, a large panel of drugs, common Hb variants (HbC, HbD, HbE, HbA2 and HbS) and cross reactants (HbA0, HbA1a+b, acetylated hemoglobin, carbamylated hemoglobin, glycated hemoglobin, glycated albumin and labile HbA1c). Conclusion The HbA1c Advanced assay on the DxC 500 AU is a precise and accurate assay, requiring no manual pretreatment and can be used for monitoring and diagnosing diabetes. *Pending clearance by the United States Food and Drug Administration and achievement of CE compliance. Not currently available for in vitro diagnostic use.

A-117 Performance Evaluation of five Sentinel Diagnostics’ Assays on Beckman Coulter DxC 500 AU Clinical Chemistry Analyzer

Abstract Objective The aim of this study is to evaluate the analytical performances of the following Sentinel Diagnostics’ assays: ACE Liquid, Lp(a) Ultra, Pancreatic Amylase, Lipase NG, Albumin BCP on the Beckman Coulter DxC 500 AU Clinical Chemistry Analyzer. Methods Performance evaluation included Limit of Blank (LoB), Limit of Detection (LoD), Limit of Quantitation (LoQ), linearity, intra assay precision, inter assay precision, calibration stability, on board reagent stability and instrument correlation, following the current CLSI guidelines protocols. Analytical Measuring Range (AMR) was defined through linearity and sensitivity. Results Summary of the analytical performances for all the assays tested is reported in table below. Conclusions All assays showed good results for the parameters tested on the Beckman Coulter DxC 500 AU Clinical Chemistry Analyzer making these kits very suitable for a routine measurement of these analytes.

B-024 An Evaluation of the Analytical Performance of the New Beckman Coulter DxC 500 AU Clinical Chemistry System

Abstract Background The Beckman Coulter DxC 500 AU clinical chemistry analyzer* is the latest system from Beckman Coulter. It is a fully automated, random-access analyzer, designed for low to medium throughput laboratories, with a throughput of 800 tests/hour including ion selective electrodes. The purpose of this study was to evaluate the analytical performance of the new DxC 500 AU and to compare the performance against the current AU480 and DxC 700 AU analyzers. Methods To assess the performance of the DxC 500 AU, Beckman Coulter assays were selected for evaluation that covered a range of sample types and assay methodologies. Precision was assessed using pooled human samples over 20 days following CLSI guideline EP05-A3. The linear range was assessed following CLSI EP06-A. The DxC 500 AU was compared to the AU480 and DxC 700 AU analyzers using a minimum of 100 samples spanning the dynamic range based on CLSI guideline EP09c-ED3. Results IgG Serum: OSR6x172 Estimates of repeatability and within laboratory precision were assessed following EP05-A3 at multiple critical analyte concentrations. The IgG serum assay exhibits total imprecision of < 6 % with a within run imprecision of ≤ 3.5 %. The IgG serum assay demonstrated acceptable linearity throughout the analytical measuring range of 75 to 3000 mg/dL following CLSI EP06-A. A method comparison study following CLSI EP09c-ED3 compared the IgG serum assay on the DxC 500 AU against the AU480 and DxC 700 AU. Serum patient samples (n > 100) measured across the analytical range were analyzed using Weighted Deming regression and yielded a slope of 1.046, an intercept of −20.2884 mg/dL and correlation coefficient R = 0.9979 against the DxC 700 AU and yielded a slope of 1.005, an intercept of −3.6578 mg/dL and correlation coefficient R = 0.9973 against the AU480. CRP Serum (Highly Sensitive): OSR6x99 Estimates of repeatability and within laboratory precision were assessed following EP05-A3 at multiple critical analyte concentrations. The CRP serum assay exhibits total imprecision of ≤10 %CV or ≤0.02 SD with a within run imprecision of ≤5 %CV or ≤0.02 SD. The CRP serum assay demonstrated acceptable linearity throughout the analytical measuring range of 0.2 to 80 mg/L following CLSI EP06-A. A method comparison study following CLSI EP09c-ED3 compared the CRP serum assay on the DxC 500 AU against the AU480 and DxC 700 AU. Serum patient samples (n > 100) measured across the analytical range were analyzed using Weighted Deming regression and yielded a slope of 0.990, an intercept of 0.0421 mg/dL and correlation coefficient R = 0.9997 against the DxC 700 AU and yielded a slope of 0.995, an intercept of −0.0008 mg/dL and correlation coefficient R = 0.9998 against the AU480. Conclusion The results of the study demonstrated excellent analytical performance of the new Beckman Coulter DxC 500 AU analyzer and confirms comparable performance to the AU480 and DxC 700 AU analyzers. *Product In development. Pending clearance by the United States Food and Drug Administration and achievement of CE compliance. Not currently available for in vitro diagnostic use.