Reagent Lots Research Articles

7953 Testosterone II (TSTII) Immunoassay Meets the CDC HoSt Certification Requirements for a Fourth Consecutive Year

Abstract Disclosure: K.N. Nissen: Employee; Self; Siemens Healthineers. N. Parker: Employee; Self; Siemens Healthineers. P. Samantha: Employee; Self; Siemens Healthineers. J.M. Rhea-McManus: Employee; Self; Siemens Healthineers. V. Shalhoub: Employee; Self; Siemens Healthineers. J. Freeman: Employee; Self; Siemens Healthineers. Background: The Atellica® IM and ADVIA Centaur® Testosterone II (TSTII) assay is enrolled in the CDC Hormone Standardization (CDC HoST) Certification Program, which is traceable to the primary testosterone Standard National Measurement Institute (NMI) M914. Certification is a yearlong process of 40 blinded samples from the CDC, 10 to be tested each quarter. If 4 consecutive quarters meet the bias acceptance criteria of ± 6.4%, CDC certification is achieved. The TSTII assay is standardized using internal standards made from United States Pharmacopea (USP)-grade testosterone. Standards are traceable to ID-LC-MS/MS by method comparison using CDC samples; ID-LC-MS/MS is traceable to the primary testosterone standard NMI M914. Methods: Initially, to standardize the assay, approximately 120 samples were obtained from CDC with CDC HoST ID-LC-MS dose values to value assign master curve standards. Multiple ADVIA Centaur TSTII reagent lots were tested with the CDC patient samples. Internal master curve standards were assayed as unknowns and dose values assigned using the RLU (system generated units–Relative Light Units) to CDC ID-LC-MS dose relationship. From 2019 to 2023, after standard value assignment, at least 179 individual patient samples from the CDC with blinded amounts of testosterone have been tested across all platforms. Each quarter, 10 blinded samples were tested in duplicate over 2 days. Results were analyzed by the CDC according to CLSI EP9-A2 for bias. Results: Correlation between the CDC assigned values and the Atellica IM, ADVIA Centaur, and ADVIA Centaur CP TSTII assay results was strong across all quarterly blind trials from 2019 to 2023 combined—Atellica IM intercept = +0.5 ng/dL, slope = 1.03, r = 0.990, n = 180, Bland Altman mean bias was 4.55%; ADVIA Centaur intercept = +0.3 ng/dL, slope = 1.04, r = 0.993, n = 179, mean bias was -0.27%; ADVIA Centaur CP intercept = +0.9 ng/dL, slope = 1.07, r = 0.993, n = 180, mean bias was 1.26%. The TSTII assay bias on all systems was consistently <6.4%. This enabled the TSTII assays to be CDC certified for a fourth consecutive year. Conclusions: The TSTII assay has consistently achieved CDC certification from 2019 to 2023. Siemens Healthineers is the only testosterone immunoassay manufacturer to be currently certified and has achieved certification for four consecutive years. Presentation: 6/1/2024

A-115 Iron assay improvement: The need for thiourea addition in Ferene/Ferrozine reagent cartridge

Abstract Background Iron assay is often ordered along with ferritin, transferrin, and iron binding capacity in patients suspected of having iron deficiency anemia or iron overload. A ferene/Ferrozine chromogen-based iron assay is more common in College of American Pathology accredited laboratories across U.S. Recently, a product recall/field safety notice was issued by a major manufacturer for several lots of ferene based iron reagent due to unacceptable positive bias in patient iron results. However, the reason(s) underlying this positive bias was not provided. In this report, we investigated the possible causes for the recall of specific lots of iron assay reagents. Methods The performance of 2 lots of recalled iron test kits was compared against 2 good lots (Sentinel Diagnostics) on the Alinity c analyzer utilizing approved calibrator lots, quality control (QC) materials (Bio-Rad Laboratories), and excess/leftover de-identified patient samples. Spectral scan (in the visible wavelength) of good and recalled lots of reagents, R1 and R2 was performed on the Tecan microplate reader. Trace elements in R1 and R2 reagents were estimated with Quantitative Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Spiking experiments in calibrator, discarded patient samples, and reagents were undertaken to further elucidate the cause and prevention of positive bias seen with recalled reagent lots. Graphs and statistical analysis were generated using Graphpad prism 10.1. Results Iron levels in QC materials and de-identified patient samples (n=42) tested with 2 recalled lot of reagents on Alinity c analyzer showed a positive bias of 15-36% compared to unimpacted lots of reagents. Calibrator and blank absorbance of recalled lots was much higher than the unimpacted lots. Percentage change in the basal absorbance of recalled vs unimpacted R2 reagent measured from 500 to 600 nm in 25 nm increments and corrected to 700 nm ranged from 150 to 250%. No such changes were noted with both R1 reagents. Interestingly, ICP-MS heavy metal panel analysis revealed that R2 reagent of the recalled lots had unanticipated presence of Cu (∼22 υg/dL) and lead (7.5 υg/L), which was not present in R1 reagents. Increased concentrations of Cu spiking (100, 200, and 400 υγ/dL) in R2 reagent from recalled lots discernibly increased the Cal Factor values as well as patient iron results relative to unspiked reagent. Further, the presence of Cu over time deteriorated the accuracy of R2 reagent reflecting on very high rise in Cal Factor and patient iron values. Interestingly, TU addition to R2 reagent from unimpacted lot prevented the Cu-induced spurious rise in Cal Factor and iron measurements in the patient samples. Further, TU exhibited sustained preventive effect on Cu-induced iron measurement changes over time. Conclusions Based on our investigation, we conclude that copper contamination of R2 reagent is the possible cause for the positive bias in the recalled iron assay reagent lots. We recommend the addition of TU to Ferene containing R2 reagent pack as a simple and effective step to prevent Cu-induced false elevation in iron values.

A-091 Evaluation of the Analytical Performance of the New Prealbumin Assay on the Atellica CH Analyzer

Abstract Background Analytical performance studies for the new Atellica® CH Prealbumin (PALB) Assay were performed to evaluate precision, detection capability, linearity, and method comparison with the Atellica® CH Prealbumin (PreAlb) Assay. Methods Precision was conducted with 3 reagent lots per CLSI EP05-A3. Daily, two runs were performed, separated by >2 hours with 2 replicates/run, for 20 days, using normal human serum, QC material (Bio-Rad Liquid Assayed Multiqual® Level 3), and normal human serum spiked with prealbumin (Cliniqa Prealbumin spike). Reproducibility was determined per CLSI EP05 A3 and internal protocols. Samples were assayed n=5 in 1 run for 5 days using 3 instruments and 3 reagent lots. Method comparison (MC) studies were conducted with 3 reagent lots per CLSI EP09C-ED3. Individual native serum samples were tested in singlicate on two Atellica® CH analyzers. Passing & Bablok regression used PALB assay as test assay and PreAlb assay as predicate assay. Where needed, MC samples were spiked with concentrated prealbumin (Clinqa Prealbumin spike) to cover the assay measuring interval. LoB and LoD testing were conducted with 3 reagent lots per CLSI EP17-A2. For LoB, four blank samples were run (n=6) per day for three days, total 72 per reagent lot. For LoD, and additional four low samples were run (n=6) per day for three days on 3 lots, on one instrument, total 72 per lot. Linearity studies followed CLSI EP06 A; low and high pools were diluted and spiked (9 levels; n=5 per level). Results The linear range was 3.0-70.0 (30-700) mg/dL (mg/L). Results are presented in the table below for detection capability, repeatability, and method comparison. Reproducibility was 2.7-6.5% at 15.0-58.4 mg/dL (150-584 mg/L). Conclusions The PALB assay detection capability, precision, linearity, and method comparison with the PreAlb assay results were acceptable. This assay is fit for use in a clinical laboratory.

A-029 Evaluation of the Analytical Performance of Four Assays Used for Diabetes on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, high-throughput integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM Assays. This study evaluated the analytical performance of the Atellica IM C-peptide (CpS) and Insulin (IRI) Assays, and the Atellica CH Enzymatic Hemoglobin A1c (A1c_E) and Fructosamine (Fruc) Assays on the Atellica CI Analyzer. Methods Precision studies were performed according to CLSI EP05-A3 using native and contrived human serum samples, except for the A1c_E assay using native and contrived human whole blood samples. One aliquot of each sample pool was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥20 days. Precision was evaluated using reagent lot and system combination varying between one to three reagent lots and one to three systems depending on the assay tested. Method comparison (MC) studies were performed using three reagent lots according to CLSI EP09c. Individual native and contrived human serum or whole blood (A1c_E) samples were analyzed using the Atellica IM Cps, IRI Assays on the Atellica IM Analyzer, the Atellica CH A1c_E, Fruc Assays on the Atellica CH Analyzer and the four Atellica IM and CH Assays presented on the Atellica CI Analyzer. Results Representative precision and MC results for each assay are listed in the table. For the four assays tested, repeatability and within-lab %CVs were <2.8% and <3.2%, respectively. Slopes determined by the Deming linear regression model were approximately equal to 1. Conclusions Evaluation of the Atellica IM Cps, IRI and Atellica CH A1c_E, Fruc Assays using the Atellica CI Analyzer demonstrated good precision and equivalent performance compared to the same assays on their respective Atellica CH and Atellica IM Analyzers.

B-347 Analytical Performance Evaluation of the High Sensitivity PSA Assay and the Free PSAII Assay on the Atellica IM Analyzer

Abstract Background Measurement of serum prostate specific antigen (PSA) levels may be used in prostate cancer (PC) screening, but elevated PSA levels also are observed in patients with other etiologies such as benign prostatic hypertrophy. Studies suggest that measuring PSA with or before digital rectal examination (DRE) provides a better method of detecting PC than DRE alone. The free prostate specific antigen (fPSA) assay is an aid for distinguishing PC from benign prostate conditions in men 50 years or older with PSA values 4.0-10.0 ng/mL (µg/L) and DRE findings nonsuspicious for PC. The goal of this study was to evaluate the analytical performance of the high sensitivity PSA (hsPSA)* and free PSA (fPSAII)* assays on the Atellica® IM Analyzer. Methods Detection capability studies were performed per CLSI EP17-A2. Precision testing was performed per CLSI EP05-A3 with native human serum and QC samples, 3 reagent lots, 1 analyzer, 2 runs/day, 2 replicates/run for 20 days. For Atellica® hsPSA and fPSAII assays a multi-site reproducibility study was conducted per CLSI EP-05 A3 using native and contrived serum samples, 3 reagent lots, and 3 different sites and analyzers; samples were assayed in triplicate for five days, two runs/day ∼2 hours apart. Linearity testing was performed per CLSI EP06-A on a dilution series made from a high PSA sample (native human male serum pool) and a low sample (native human female serum), 4 replicates, 3 reagent lots, and 1 analyzer. Specimen equivalency was determined by Weighted Deming regression model per CLSI EP09c-ed3. Results Results are presented in the table. Conclusions The Atellica IM hsPSA assay and fPSAII assays detection capability, precision, linearity, and specimen equivalency were acceptable. *CAUTION: Investigational Device. Not available for sale. Future availability cannot be guaranteed. The results are preliminary and were achieved in unique setting with no expected timeline for completion.

A-030 Evaluation of the Analytical Performance of Two Reproductive Endocrinology Related Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, high-throughput integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM Assays. This study evaluated the analytical performance of the Atellica IM Sex Hormone Binding Globulin (SHBG) and the total Testosterone II (TSTII) Assays on the Atellica CI Analyzer. Methods Precision studies were performed according to CLSI EP05-A3 using native and contrived human serum samples. One aliquot of each sample pool was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥20 days. Precision studies were evaluated with one reagent lot on two systems. Method comparison (MC) studies were performed using three reagent lots according to CLSI EP09c. Individual native and contrived human serum samples were analyzed using the Atellica IM SHBG and TSTII Assays on the Atellica IM Analyzer and the Atellica CI Analyzer. LoB, LoD, and LoQ were determined as described in CLSI protocol EP17-A2. Results Representative precision and MC results for each assay are listed in the table. For the two assays tested, repeatability and within-lab %CVs were <4.0% and <6.6%, respectively. Slopes determined by the Deming linear regression model were approximately equal to 1. Detection capability for the Atellica IM SHBG Assay on the Atellica CI Analyzer was estimated at 1.33 nmol/L (standard international (SI) units; 0.13 μg/mL, common units), 1.60 nmol/L (0.15 μg/mL) and 2.00 nmol/L (0.19 μg/mL) for LoB, LoD, and LoQ respectively. When using the Atellica IM TSTII Assay, detection capability was estimated at 0.09 nmol/L (2.50 ng/dL), 0.17 nmol/L (5.00 ng/dL) and 0.24 nmol/L (7.00 ng/dL) for LoB, LoD, and LoQ, respectively. Conclusions Evaluation of the Atellica IM SHBG and TSTII Assays using the Atellica CI Analyzer demonstrated good precision and equivalent performance compared to the same assays on the Atellica IM Analyzer.

B-340 Evaluation of the Analytical Performance of Three Major Immunoglobulins Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, high-throughput integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM Assays. This study evaluated the analytical performance of the the Atellica CH Immunoglobulin A_2 (IgA_2), Immunoglobulin G_2 (IgG_2), and Immunoglobulin M_2 (IgM_2) Assays on the Atellica CI Analyzer. Methods Precision studies were performed according to CLSI EP05-A3 using native and contrived human serum samples. One aliquot of each sample was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥20 days. Precision was evaluated using three reagent lots on one system. Method comparison studies were performed using three reagent lots according to CLSI EP09c. Individual native and contrived human serum samples were analyzed using the Atellica CH IgA_2, IgG_2, and IgM_2 Assays on the Atellica CH Analyzer and the Atellica CI Analyzer. LoB and LoD were determined as described in CLSI EP17-A2. Results Representative precision and method comparison results for each assay are listed in the table. For the three assays tested, repeatability and within-lab %CVs were <1.8% and <3.9%, respectively. Slopes determined by the Deming linear regression model were approximately equal to 1. Detection capability for the Atellica CH IgA_2 Assay on the Atellica CI Analyzer was estimated at 1.6 mg/dL (0.02 g/L) and 3.6 mg/dL (0.04 g/L) for LoB, and LoD. For the Atellica CH IgG_2 Assay, LoB and LoD were determined at 7 mg/dL (0.07 g/L) and 21 mg/dL (0.21 g/L). For the Atellica CH IgM_2 Assay, LoB and LoD were determined at 5.0 mg/dL (0.05 g/L) and 8.0 mg/dL (0.08 g/L). Conclusions Evaluation of the Atellica CH IgA_2, IgG_2, and IgM_2 Assays using the Atellica CI Analyzer demonstrated good precision and equivalent performance compared to the same assays on the Atellica CH Analyzer.

A-128 Evaluation of the Analytical Performance of Three Inflammation Related Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, high-throughput integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM Assays. This study evaluated the analytical performance of the the Atellica CH Complement C3 (C3), Complement C4 (C4), and Alpha-1-acid Glycoprotein (AAG) Assays on the Atellica CI Analyzer. Methods Precision studies were performed according to CLSI EP05-A3 using native and contrived human serum samples. One aliquot of each sample was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥20 days. Precision was evaluated using three reagent lots on one system. Method comparison (MC) studies were performed using three reagent lots according to CLSI EP09c. Individual native and contrived human serum samples were analyzed using the Atellica CH C3, C4, and AAG Assays on the Atellica CH Analyzer and the Atellica CI Analyzer. LoB and LoD were determined as described in CLSI EP17-A2. Results Representative precision and MC results for each assay are listed in the table. For the three assays tested, repeatability and within-lab %CVs were <1.4% and <3.3%, respectively. Slopes determined by the Deming linear regression model were approximately equal to 1. Detection capability for the Atellica CH C3 Assay on the Atellica CI Analyzer was estimated at 0.2 mg/dL (0.00 g/L) and 0.4 mg/dL (0.00 g/L) for LoB, and LoD. For the Atellica CH C4 Assay, LoB and LoD were determined at 0.1 mg/dL (0.00 g/L) and 0.2 mg/dL (0.00 g/L). For the Atellica CH AAG Assay, LoB and LoD were determined at 0.9 mg/dL (0.01 g/L) and 2.0 mg/dL (0.02 g/L). Conclusions Evaluation of the Atellica CH C3, C4, and AAG Assays using the Atellica CI Analyzer demonstrated good precision and equivalent performance compared to the same assays on the Atellica CH Analyzer.

B-263 Analytical Performance Evaluation of Eleven Drug of Abuse Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, high-throughput integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM Assays. This study evaluated the analytical performance of the Atellica CH Amphetamines (Amp), Barbiturates (Brb), Benzodiazepine (Bnz), Cannabinoids THC (Thc), Cocaine Metabolite (Coc), Ecstasy (Xtc), Methadone (Mdn), Opiates (Op), Oxycodone (OXY), Phencyclidine (Pcp), and Propoxyphene (Ppx) Assays on the Atellica CI Analyzer. Methods Precision and method comparison (MC) studies were used as performance indicators. Precision studies were performed according to CLSI EP05-A3 using quality control (QC) samples consisting of contrived human urine samples. One aliquot of each QC was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥ 20 days. Precision for each assay was evaluated with one reagent lot on one system. Method comparison studies were performed with three reagent lots according to CLSI EP12-A2. Individual native and contrived human urine samples were analyzed using the Atellica CH Amp, Barb, Bnz, Thc, Coc, Xtc, Mdn, Op, OXY, Pcp, and Ppx Assays on both the Atellica CH and Atellica CI Analyzers. The results were assessed based on analyte values used for distinguishing positive (value ≥cutoff) and negative (value <cutoff) specimens. Results As shown in table below, repeatability and within-lab %CVs based on manufacturer arbitrary units (mAU) were <0.8% and <3.2%, respectively or qualitative interpretation for each replicate remained unchanged for all 80 precision testing measurements (OXY, PcP). Qualitative accuracy assessed by concordance analysis demonstrated ≥95% agreement between the Atellica CI Analyzer and Atellica CH Analyzer. Conclusions Evaluation of the Atellica CH Amp, Barb, Bnz, Thc, Coc, Xtc, Mdn, Op, OXY, Pcp, and Ppx Assays using the Atellica CI Analyzer demonstrated acceptable precision and equivalent performance compared to the same assays on the Atellica CH Analyzer.

B-309 Evaluation of the Analytical Performance of Breast and Ovarian Cancer Antigen Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, high-throughput integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM Assays. This study evaluated the analytical performance of the Atellica IM breast cancer antigen CA 15-3™ (CA 15-3) and the ovarian cancer antigen CA 125II™ (CA 125II) Assays on the Atellica CI Analyzer. Methods Precision studies were performed according to CLSI EP05-A3 using native and contrived human serum samples as well as contrived horse serum samples for CA 15-3. One aliquot of each sample pool was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥20 days. Precision studies were evaluated with one reagent lot on two systems. Method comparison studies were performed using three reagent lots according to CLSI EP09c. Individual native and contrived human serum samples were analyzed using the Atellica IM CA 15-3 and CA 125II Assays on the Atellica IM Analyzer and the Atellica CI Analyzer. LoB, LoD, and LoQ were determined as described in CLSI EP17-A2. Results Representative precision and method comparison results for each assay are listed in the table. For the two assays tested, repeatability and within-lab %CVs were <2.4% and <6.9%, respectively. Slopes determined by the weighted Deming linear regression model were approximately 1. Detection capability for the Atellica IM CA 15-3 Assay on the Atellica CI Analyzer was estimated to be 1.0 U/mL, 2.0 U/mL and 3.0 U/mL for LoB, LoD, and LoQ, respectively. When using the Atellica IM CA 125II Assay, detection capability was estimated to be 2.0 U/mL, 3.0 U/mL and 3.0 U/mL for LoB, LoD, and LoQ, respectively. Conclusions Evaluation of the Atellica IM CA 15-3 and CA 125II Assays using the Atellica CI Analyzer demonstrated good precision and equivalent performance compared to the same assays on the Atellica IM Analyzer.

B-045 Evaluation of the Analytical Performance of Three Sepsis Related Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, high-throughput integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM Assays. This study evaluated the analytical performance of the Atellica IM BRAHMS Procalcitonin (PCT) Assay, and the Atellica CH Revised C-Reactive Protein (RCRP) and Lactate_3 (Lac_3) Assays on the Atellica CI Analyzer. Methods Precision studies were performed according to CLSI EP05-A3 using native and contrived human serum (PCT, RCRP) or plasma and cerebrospinal fluid (Lac_3) samples. One aliquot of each sample pool was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥20 days. Precision studies were evaluated with one to three lots of reagent on one to two systems. Method comparison (MC) studies were performed using three reagent lots according to CLSI EP09c. Individual native and contrived human serum (PCT, RCRP) or plasma and cerebrospinal fluid (Lac_3) samples were analyzed using the Atellica IM PCT Assay on the Atellica IM Analyzer, the Atellica CH RCRP, Lac_3 Assays on the Atellica CH Analyzer and all three Atellica IM and CH Assays listed above on the Atellica CI Analyzer. Results Representative precision and MC results for each assay are listed in the table. For the three assays tested, repeatability and within-lab %CVs were <1.4% and <8.9%, respectively. Slopes determined by the Deming linear regression model were approximately equal to 1. Conclusions Evaluation of the Atellica IM PCT and Atellica CH RCRP, Lac_3 Assays using the Atellica CI Analyzer demonstrated good precision and equivalent performance compared to the same assays on their respective Atellica CH and Atellica IM Analyzers.

B-113 Beckman Coulter DxI 9000 immunoassay analyzer assay performance meets new CLIA 2024 performance goals with highest proportion of Six Sigma performance amongst all major manufacturers

Abstract Background The Clinical Laboratory Improvement Act (CLIA) proficiency testing (PT) criteria will be updated in July 2024 with some goals tightening by up to 40%. It is assumed, but not known, that all assays and instruments will be able to achieve these goals. Using these new CLIA 2024 goals, estimates of current instrument group performance from an international proficiency testing (PT) survey have shown significant differences in quality, calling into question which assays can achieve the new CLIA goals. Currently, the highest performing diagnostic instrument achieves only 35.2% 6-Sigma, while the majority of instruments have less than 15% 6-Sigma performance indicating a higher probability of future PT failures. Methods Eighteen assays that will be governed by new CLIA 2024 goals were assessed for Sigma metric performance on the DxI 9000 immunoassay analyzer: Alpha Fetoprotein (AFP), Beta hCG, Carcinoembryonic antigen (CEA), Cortisol, Creatine Kinase MB (CK-MB), Estradiol, Ferritin, Folate, Follicle-Stimulating Hormone (FSH), Prolactin, Para-thyroid hormone (PTH), Total Prostate specific antigen (Total PSA), Testosterone, Thyroid Stimulating Hormone (TSH), Total Triiodothyronine (TT3),high sensitivity Troponin I, Total Thyroxine (TT4) and Vitamin B12. Precision and bias were determined following CLSI EP5 and EP9 guidelines, measured across 3 reagent lots. CLIA 2024 PT criteria provides the allowable total error for the standard Sigma-metric calculation: Sigma-metric = (TEa - |bias|) / SD Performance of the other major analyzers was assessed using the methodology introduced in 2006 by Westgard JO and Westgard SA. The Sigma-metric predicts future problems with PT and potential optimization of QC procedure opportunities, including fewer Westgard Rules, control levels, even reduced QC frequency and materials leading to less cost and time saved. Results Half (50%) of the assays on DxI 9000 achieves 6-Sigma, outperforming all other major manufacturers in the market who range from only 5% to 35% 6-Sigma. Further, over 78% of the DxI 9000 performance was 4Sigma and higher. Less than 8% of performance fell below 3-Sigma, which was observed at the extreme ends of the reportable range. Conclusions The DxI 9000 assay performance is well designed to meet CLIA 2024’s new PT criteria and has the highest prevalence of 6-sigma assay performance observed on market when compared to the top 5 major instrument manufacturers. Assays with Sigma metrics at 4-Sigma and higher are unlikely to face analytical PT difficulties and can be optimized for reduced Westgard Rules, control levels, and potentially even QC frequency.

B-143 Using Big Data Analytics to Measure the Multi-year Consistency of Sigma Metrics for Vitros Oncology Assays

Abstract Background Sigma metrics assess lab quality by incorporating precision, accuracy and total error allowed (TEa). Sigma metrics report quality on a 0-6 scale, with 6 representing World-Class quality. Due to logistical constraints, Sigma metrics are often calculated with limitations such as a small number of analyzers, single reagent lot or short duration. QuidelOrtho developed a novel approach using big data analytics for the objective, automated calculation of Sigma metrics across thousands of Vitros analyzers running in real lab conditions. This approach was previously used to report the Sigma metric performance for 115 assays using data from 2022. Of particular interest is the consistency of quality levels for Vitros oncology assays assessed in the study. The aim of this analysis was to examine Sigma metrics for Vitros oncology assays and compare Sigma metrics to data from 2022. Methods The methods follow the previous approach using the same Python algorithm to extract worldwide QC data from Jan. to Nov. 2023 (inclusive). A QC fluid lot from the study period was selected for each analyte to align with the fluid level reported in the 2022 study, which was based on medical relevance. Metrics were calculated for each set of QC data that originated from a single analyzer, reagent lot and calibration curve; the median Sigma metric is reported in the Results. Proficiency testing limits were utilized as TEa limits where available, with preference to CLIA 2024 limits. Results The following assays reported Sigma metrics as >6 using both 2022 and 2023 data: alpha-fetoprotein, cancer antigen 125, carcinoembryonic antigen, prostate-specific antigen (PSA), free PSA, IgA, and IgG. Assays with higher metrics using 2023 data: cancer antigen 19-9 (5.0 vs >6) and IgM (5.3 vs >6). Assays with lower metrics using 2023 data: cancer antigen 15-3 (4.8 vs 4.4). Conclusions Vitros oncology assays report similar performance for 2022 and 2023. All Vitros oncology assays assessed report Sigma metrics of 4 or greater, indicating they achieve results within the corresponding allowable error.

A-084 Performance evaluation of Sentinel Diagnostics’ Ammonia Ultra assay on Beckman Coulter AU/DxC AU Systems

Abstract Background The analytical performances of the Ammonia Ultra assay for in vitro quantitative enzymatic determination of Ammonia in human plasma have been evaluated on Beckman AU/DxC AU Systems. Ammonia, derived from the amino acids catabolism and from the action of intestinal bacteria on dietary proteins, is converted to non-toxic urea by the liver. An excess of ammonia can have toxic effects on the Central Nervous System with possible neurological disturbances. Elevated ammonia levels can also be observed in severe liver failure as may occur in Reye’s syndrome, viral hepatitis or cirrhosis. Methods Ammonia, in the presence of glutamate dehydrogenase (GLDH), combines with alpha-ketoglutarate and NADH to yield glutamate and NAD+. The decrease in 340 nm absorbance (NADH → NAD+) is proportional to the ammonia level in the examined plasma. The reagent contains excess of lactate dehydrogenase (LDH) to rapidly reduce endogenous pyruvate and avoid its interference with the assay system. Performances evaluation have been done following current CLSI guidelines protocols. Results 3 calibrator lots and 2 reagent lots have been used for testing. For each test and among different combinations of reagents and calibrators, worst case has been reported in the table. Conclusions Analytical performances of Ammonia Ultra assay on Beckman AU/DxC AU Systems meet the requirements for its use as quantitative determination of Ammonia in human plasma and make this assay very suitable for the routine measurement of this analyte.

A-119 Lipemia Interference

Abstract Background Lipemic specimens is a common problem in clinical laboratories. Analytical results may be perturbed by lipemia, leading to misdiagnosis and unnecessary treatments for patients. Serum index testing is an important preanalytical test for assessing the potential effect of endogenous HIL interferents (hemoglobin (H), bilirubin (I) or lipids (L)) on test results. Automated HIL systems are not standardized and differ in their response. HIL induced interference should be verified by all clinical laboratories. Intralipid, a commercial lipid emulsion with particle size ranges from 200 to 600 nm is often used to verify the L index. However, intralipid lacks particles that mimic large VLDL, as well as the lower and upper ranges for chylomicrons size. In contrast, patient samples contain a complex mixture of macromolecular lipid and protein structures. Therefore, lipemia induced by Intralipid is not identical to lipemia in patient serum samples. The purpose of this study is to increase awareness of lipid interference and demonstrate the relationship of a lipid L Index to intralipid and triglyceride interference. Methods A set of 16 panels were prepared from a commercially available Triglyceride rich Lipoprotein material. These panels spanned a lipid concentration from 0 to 3000 mg/dL. Panels were tested on the Alinity c and ARCHITECT c8000 TRIG2 assays (04U0615 and 04T1016 respectively) on 2 reagent lots in a single run to determine the Triglyceride concentration. Then these samples were assessed for an HIL L score using the Abbott HIL saline protocol. Results The relationship between the Triglyceride rich Lipoprotein and the L Index was linear with a high correlation (r= 0.999) for Alinity and ARCHITECT respectively. The L Index underestimated the Triglyceride Rich Lipoprotein concentration. The reason for the lower estimate of Triglyceride rich lipoprotein specimens on an L Index is likely due to the differences in size of the lipid particles between the two artificial lipid materials, Intralipid and Triglyceride rich lipoprotein. In addition, while the triglyceride assay provides a quantitative measurement of the lipemic concentration, the L Index is designed to provide an estimated result. Conclusions Intralipid is an acceptable material used to verify spectrophotometric HIL systems. The L Index provides an estimate of sample turbidity, not the concentration of Triglyceride. Vendor purchased human derived Triglyceride rich lipoprotein, which contains a heterological mixture of lipid particles, may be regarded as a more appropriate material for assessing lipid interference. Thus, while recovery of the L Index correlates well to the Intralipid concentration, it can have a poorer correlation with vendor purchased samples containing Triglyceride due to the different vesicle sizes in these materials. This study demonstrates the Triglyceride rich material used to assess lipid interference in Sigma Strong assays provides a difference in response between the Triglyceride concentration of this material determined on a Triglyceride assay vs the L Index. The choice of lipemic material to use, (eg. artificial, native), can influence the results. Thus, care should be taken in comparing results for these materials.

A-003 Beckman Coulter DxI 9000 Immunoassay Analyzer’s High Sensitivity Troponin I achieves >90% six sigma performance when assessed against clia 2024 performance goals

Abstract Background In July 2024, the Clinical Laboratory Improvement Act (CLIA) proficiency testing (PT) criteria will directly regulate Troponin I performance for the very first time. The new CLIA goal is 0.9 ng/mL or 30%, whichever is greater. CAP previously set a goal of 30% or 3 times the group standard deviation (SD), whichever is greater, a more permissive setting. Estimates of current instrument group performance from an international proficiency testing (PT) survey have shown none of the 5 major diagnostic instruments can achieve the biological minimum goal at a 6-Sigma level, while 4 of the 5 instruments perform at 3 Sigma or below. Performance of these platforms was assessed using the methodology introduced in 2006 by Westgard JO and Westgard SA. The DxI 9000 high sensitivity Troponin I assay was assessed to determine if it could achieve the new CLIA 2024 goals. Methods The DxI 9000 high sensitivity Troponin I assay was assessed with three reagent lots, on both serum and Lithium Heparin (LiHep) samples, following Clinical Laboratory Standards Institute (CLSI) protocols EP05 and EP09 to estimate imprecision and bias. The new CLIA 2024 PT criteria supplied the allowable total error for the standard Sigma-metric calculation: Sigma-metric = (TEa - |bias|) / SD The Sigma-metric predicts not only future problems with PT, but also potential optimization of QC procedures, including fewer Westgard Rules, control levels, even reduced QC frequency which can lead to less cost, time, and materials. Results The majority (91.7%) of data points across the analytical measuring range for DxI 9000’s high sensitivity Troponin I assay from both serum and LiHep samples achieved 6-Sigma performance. For serum, only 8.3% of samples achieved 5-sigma performance. For LiHep, only 4.2% of the performance was 4 Sigma. None of the performance was 3 Sigma or lower. Conclusions The superior precision observed on DxI 9000 high sensitivity Troponin I delivers overwhelming 6-sigma performance when assessed by CLIA’s 2024 goal. This assay is highly unlikely to face PT difficulties and can be optimized for reduced Westgard Rules, reduced control levels leading to a reduction in time, materials, and cost.

B-144 Sigma Metrics for Vitros Reproductive Endocrinology Assays Across Multiple Fluid Levels

Abstract Background Sigma metrics assess laboratory quality by incorporating precision, accuracy and total error allowed (TEa). Sigma metrics report quality on a scale of 0 to 6, with 6 representing the World-Class quality. QuidelOrtho developed a novel approach using big data analytics for the objective and automated calculation of Sigma metrics across thousands of Vitros® Analyzers running in real laboratory conditions. This approach was previously used to report the Sigma metric performance for 115 assays using data from 2022. A limitation of that study is the metrics were reported for a single fluid that was selected for medical relevance. However, reproductive endocrinology assays have complex medical utilization and there is a benefit to understanding Sigma metrics at multiple levels. The aim of this poster is to provide additional data on the Sigma metrics for reproductive endocrinology assays. Methods The methods follow the previous approach using the same Python algorithm to extract QC data from Jan. to Aug. 2022 (inclusive). Up to seven QC fluid lots were selected for each analyte. Metrics were calculated for each set of QC data that originated from a single analyzer, reagent lot and calibration curve; the median Sigma metric is reported in the Results. Proficiency testing limits were utilized as TEa limits where available, with preference to CLIA 2024 limits. Results Sigma metrics are reported for multiple fluids for the following assays: estradiol, follicular stimulating hormone, luteinizing hormone, progesterone, prolactin, testosterone, human chorionic gonadotropin, and thyroid stimulating hormone. All fluids examined report Sigma metrics greater than 4, which is considered “Good” performance. An exception is luteinizing hormone which has Sigma metrics = 1.9 at the lowest reported concentration. Conclusions Vitros reproductive endocrinology assays report strong Sigma metrics across multiple concentrations, indicating they are highly capable of achieving results within the allowable error.

A-237 Analytical Performance Evaluation of Cytomegalovirus IgG and Syphilis Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, high-throughput integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM Assays. This study evaluated the analytical performance of the Atellica IM Cytomegalovirus IgG (CMV IgG) and Syphilis (Syph) Assays on the Atellica CI Analyzer. Methods Precision studies were performed according to CLSI EP05-A3 using native and contrived human serum samples. CMV IgG and Syph Assays were evaluated with one reagent lot on two Atellica CI analyzers. One aliquot of each sample was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥20 days. Method comparison studies were performed according to CLSI EP12-A2. Individual native human serum samples were analyzed using the Atellica IM CMV IgG and Syph Assays on the Atellica IM and Atellica CI Analyzers. The results were assessed based on Index values distinguishing reactive (Index ≥cut-off value) and nonreactive (Index <cut-off value) specimens. Results As shown in table below, repeatability and within-lab %CVs for the two assays presented were <3.7% and <7.0%. Negative and positive agreement were 100% for the 111 nonreactive CMV IgG samples and the 169 CMV IgG reactive samples tested. Negative and positive agreement were 100% for the 103 Syph reactive samples and the 126 nonreactive Syph samples tested. Overall clinical agreement between each of the presented assays on the Atellica CI Analyzer and Atellica IM Analyzer was 100%. Conclusions Evaluation of the Atellica IM CMV IgG and Syph Assays using the Atellica CI Analyzer demonstrated acceptable precision and equivalent performance compared to the same assays on the Atellica IM Analyzer.

A-061 Analytical Performance and R55G Mutant Detection Ability of an Improved Thyroid-Stimulating Hormone Assay, TSH3-Ultra II, on the ADVIA Centaur Immunoassay System and the Atellica IM Analyzer

Abstract Background Measurement of thyroid stimulating hormone (TSH) is a critical tool for the investigation of thyroid disorders. Previous studies have demonstrated that some immunoassays are unable to detect TSH from patients with the R55G mutation in the TSHβ subunit. This study evaluated the analytical performance of the ADVIA Centaur® and Atellica® IM TSH3-Ultra II (TSH3ULII) assay and its ability to detect the R55G TSH mutant. Methods Limit of quantitation (LoQ) and linearity were determined as described in CLSI EP17-A2 and EP06, respectively. Precision and method comparison (MC) studies were performed with three reagent lots according to CLSI EP05-A3 and CLSI EP09c using native and contrived human serum and plasma samples. For precision, one aliquot of each sample was tested in duplicate in two runs per day >2 hours apart on each analyzer for ≥20 days. MC studies were performed by testing native human serum samples using ADVIA Centaur TSH3-UL assay (current TSH assay) and the newer ADVIA Centaur TSH3ULII assay. An additional MC was performed by testing native human serum samples with the TSH3ULII assay on both the ADVIA Centaur XP and the Atellica IM Analyzer. Samples from 61 patients with TSH results below the LoQ when using TSH3-UL were sequenced and confirmed to have the R55G mutant. Each of these samples was tested in duplicate using the ADVIA Centaur TSH3ULII assay. Results LoQ on both the ADVIA Centaur XP and the Atellica IM Analyzer was estimated to be 0.010 μIU/mL (mIU/L). Linearity was verified from 0.010 to 150.000 μIU/mL (mIU/L). ADVIA Centaur TSH3ULII repeatability %CVs ranged from 1.4 to 3.6% at 0.099 and 91.993 μIU/mL (mIU/L), and within-lab %CVs ranged from 2.3 to 6.2% at 4.908 and 91.993 μIU/mL, respectively. Atellica IM TSH3ULII repeatability %CVs ranged from 1.1 to 3.4% at 4.800 and 93.097 μIU/mL, and within-lab %CVs ranged from 2.2 to 4.6% at 0.103 and 93.097 μIU/mL, respectively. For the MC studies, slopes determined by the Passing-Bablock regression model were approximately 1 (0.96-0.97 range) across the sample interval tested. All TSH3ULII results from the 61 mutant patient samples were greater than LoQ, ranging from 0.864 to 23.443 μIU/mL (mIU/L). Conclusions Evaluation of the TSH3ULII assay using the ADVIA Centaur system demonstrated performance comparable to the commercially available TSH3-UL assay for LoQ, linearity, and precision, when using normal patient samples. TSH3ULII results on the Atellica IM Analyzer were comparable to the results obtained on the ADVIA Centaur XP. All 61 TSH mutant samples used in this study that had TSH values below the LoQ with the TSH3-UL assay, were detectable with the TSH3ULII assay. The data presented here demonstrate the ability of the TSH3ULII assay to detect the TSH in samples from patients with the R55G mutation.

B-279 Evaluation of the Analytical Performance of Two Therapeutic Drug Monitoring Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, high-throughput integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM Assays. This study evaluated the analytical performance of the Atellica IM Digoxin (Dig), and the Atellica CH Lithium_2 (LITH_2) Assays on the Atellica CI Analyzer. Methods Precision studies were performed according to CLSI EP05-A3 using native and contrived human serum samples. One aliquot of each sample pool was tested in duplicate in two runs per day ≥2 hours apart on each analyzer for ≥20 days. Precision studies were evaluated with one to three lots of reagent lot on one to two systems. Method comparison studies were performed using three reagent lots according to CLSI EP09c. Individual native and contrived human serum samples were analyzed using the Atellica IM Dig Assay on the Atellica IM Analyzer, the Atellica CH LITH_2 Assay on the Atellica CH Analyzer and both assays on the Atellica CI Analyzer. Results Representative precision and method comparison results for each assay are listed in the table. For the two assays tested, repeatability and within-lab %CVs were <5.4% and <8.0%, respectively. Slopes determined by the Deming linear regression model were approximately equal to 1. Conclusions Evaluation of the Atellica IM Dig Assay and the Atellica CH LITH_2 Assay using the Atellica CI Analyzer demonstrated good precision and equivalent performance compared to the same assays on their respective Atellica CH and Atellica IM Analyzers.