Method Comparison Research Articles

Modified torso vs distal limb electrode placement for performing ECGs in children: A method comparison study

BackgroundThe electrocardiogram (ECG) is routinely performed in children with the limb electrodes positioned on the torso, but few studies have investigated the effects of this modification on the pediatric ECG.Our objective was to assess the agreement between the standard limb lead configuration and a modified torso electrode configuration in normal, healthy children, and to assess the effect of height on that agreement. Methods185 children aged 5–18 years underwent two consecutive 12‑lead ECGs, one with standard distal limb lead placement and one with the limb leads placed on the torso. Agreement was assessed for 17 ECG parameters (intervals, axes, and amplitudes) using Bland-Altman plots, height-dependent mean error, and false positive rates. ResultsThe torso configuration systematically biased the QRS and P wave axes rightwards (towards aVF). Adequate agreement was observed for PR interval and QRS duration, but QTc limits of agreement (±40 ms) were wide. The torso configuration overestimated left-precordial Q, R, and S wave amplitudes and underestimated right-precordial R and S wave amplitudes compared to the distal limb placement. Mean measurement errors increased with the magnitude of the ECG parameter. Mean and variance of measurement errors were more pronounced in shorter children. False positive rates did not differ between the torso and distal limb configurations. ConclusionModified placement of the limb electrodes onto the torso resulted in multiple differences in the pediatric ECG signals. This may lead to misclassification of electrocardiographic abnormalities, particularly in children with measurement values at the upper limits of normal.

On the Use of Image Analysis for Hematocrit Evaluation in Dried Blood Spots

Dried blood spots (DBSs) are formed by collecting a small sample of blood on specialized filter paper and allowing it to dry naturally. Various domains of life sciences and drug research extensively use DBSs as a sampling technique. The “Hematocrit (Ht) effect” affects assay bias, and several strategies have been put forth to deal with it, including the correction of quantified concentrations using an appropriate correction factor. The approach was previously applied, following the utilization of an image processing algorithm developed in Matlab® to derive a reliable equation correlating DBS areas to Ht% values. The present work looks more closely at the application of image analysis to the evaluation of Ht in DBS samples. Utilizing image analysis software, DBS samples with known Ht values were processed. Preparation of cards has followed a previously developed protocol for the appropriate formation of uniform area DBSs, irrespective of Ht. The resulting areas showed close resemblance to the respective theoretical areas calculated by applying the correlation equation. Following that, the equation was utilized to determine the Ht values for each sample, and a comprehensive comparison of measured versus calculated Ht was carried out using various statistical approaches for method comparison. The results demonstrated a strong correlation, suggesting the method’s viability in estimating Ht for unknown DBS samples.

Momentum flux coefficient effect on vertical two-phase flows: Numerical method comparison

The governing equations of two-phase flows have a safe operating range, and exceeding this range can negatively impact the results. To extend this safe range, one key strategy is to incorporate the momentum flux coefficient into the governing equations. This paper introduces the application of the momentum flux coefficient to no-pressure or free-pressure model equations for the first time, specifically evaluating its performance in downward co-current two-phase flows through numerical methods. A new and improved version of the no-pressure model is also presented. Findings suggest that the force approach method yields more accurate results compared to other methods, whereas the Richmeier method produces unrealistic outcomes at discontinuities. A comparison between the standard and the developed no-pressure models reveals that the latter does not prevent nonphysical mutations and even exacerbates their occurrence. However, the developed no-pressure model successfully reduces numerical distribution production.

Health assessment method of front landing gear hydraulic retraction and extension system based on GRNN

With the continuous development of civil aircraft health management technology, the status monitoring data of important aircraft systems and components are constantly enriched. The health status of the front landing gear hydraulic retraction system has a great impact on the take-off and landing of the aircraft. Although the system has multi-dimensional monitoring parameters, it is difficult to effectively use the system monitoring data to accurately evaluate its health status. Aiming at the health assessment problem of the front landing gear hydraulic retraction system, this paper builds a simulation model of the system through AMESim software modeling, and studies the influence of the performance changes of hydraulic component parameters on the front landing gear retraction performance. The performance data of the front landing gear retraction actuator at different levels of failure are used as the original data, and the characterization parameters such as retraction time and maximum flow rate are extracted. A health index construction method based on generalized regression neural network (GRNN) is proposed, which can more effectively evaluate the health status of the system. Its effectiveness and accuracy are proved by method comparison.

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

6651 A Traceable Clinical Free Thyroxine Assay Based on Equilibrium Dialysis ID-LC/MS/MS

Abstract Disclosure: D. Spector: None. L. Zhang: None. A. Ribera: None. A. Doty: None. C. Tse: None. O. Sugahara: None. N. Vazquez: None. U. Danilenko: None. H.W. Vesper: None. Accurate diagnosis and effective treatment of thyroid diseases rely on reliable thyroid function tests. Serum free thyroxine (FT4) immunoassays (IAs) are most commonly used for FT4 measurements in clinical practice. However, FT4 IAs have not been standardized with large variations between different assay platforms. A reference measurement procedure (RMP) for FT4 based on well-defined equilibrium dialysis (ED) of serum has been established for CDC standardization program to support the standardization of clinical assays for patient care. In the current study, we aim to develop a routine clinical FT4 assay based on ED-LC/MS/MS that is traceable to the RMP. ED-LC/MS/MS analysis was performed using a commercially available micro-ED plate. FT4 in dialysate was extracted with a 96-well C18 SPE plate. FT4 in the samples was quantitated by using LC/MS/MS in positive ion mode. The assay was calibrated with the certified primary reference material. By using RMP as a reference, we compared the analysis of 40 single donor sera between the ED-LC/MS/MS assay and FT4 IA on Roche e401platform. ED-LC/MS/MS assay could resolve T4, T3, reverse triiodothyronine (rT3), and other interferences in the samples with C18 chromatography in 4 min. The linear range of the routine FT4 assay was from 0.5-100 pg/mL covering clinically relevant FT4 concentrations including hypo-, hyperthyroid patient samples. The intra and inter-run CV% of the assay in 20 days was 3.72 and 5.25%, respectively. The effect of minor changes to the method conditions was studied. It was determined that serum/buffer ratios from 1:1 to 1:2 in the ED inserts, speeds of shaker for ED, and ED incubation time, did not influence the FT4 measurement. However, elevated ED temperature at 38°C could result in a more than 10% increase in FT4 values. A microplate format for the procedures of ED and SPE is amiable to the application of an automation system which significantly improves the throughput of the procedure. Method comparison showed good agreement between ED-LC/MS/MS assay and RMP in Deming regression analysis with a slope close to 1, while there was significant bias of IA from RMP. ED-LC/MS/MS assay was also applied for pregnancy serum samples with minimal difference on the FT4 measurement from RMP. We have developed a routine clinical FT4 assay that is traceable to RMP. The accuracy, precision, and sensitivity of the assay are suitable for high-throughput FT4 measurements in clinical laboratories and large epidemiologic studies. We demonstrate that the developed method can provide accurate FT4 measurements in patients including pregnant women. Presentation: 6/3/2024

A sensitive immunoassay for the quantitation of Pig-MAP in pig saliva samples

The purpose of the study is to develop a sensitive assay for the proper quantification of the acute phase protein Pig-MAP in pig saliva samples. A time-resolved immunofluorometric assay (TR-IFMA) was developed using two pig-MAP-specific monoclonal antibodies. The limit of detection of the assay was 4 ng/mL, enough to measure pig-MAP concentration in saliva. Precision was evaluated for saliva samples of low, medium and high concentration, with inter assay CV of 4–14 % and inter-assay CV of 8–20 %. The assay kept linearity under dilution and a method comparison study performed with serum samples showed good correlation with ELISA. Median Pig-MAP concentration in saliva from healthy animals was 19 ng/mL whereas in pigs with different inflammatory conditions was 11 times higher. In the same animals median pig-MAP serum concentrations were 0.72 mg/mL in the healthy group and 4.61 in the diseased group. The Spearman coefficient of correlation between Pig-MAP concentration in serum and saliva was of 0.72. A correlation was also observed between the salivary concentration of pig-MAP and other two acute phase proteins such as haptoglobin (r = 0.62) or C-reactive protein (r = 0.65). The concentration of Pig-MAP in saliva of pigs with severe respiratory disease decreased significantly from a median value of 128 ng/mL at the time of disease detection to 8 ng/mL after 1 day of antibiotic therapy. Studies performed show that pig-MAP is present in saliva and this specimen may be an alternative to serum for pig-MAP quantification.

7701 Comparative Analysis of Dried Blood Spot and Serum ELISAs for AMH, FSH, and LH in Patients Seeking IVF Treatment

Abstract Disclosure: T. Kumar: None. R. Chauhan: None. B. Kalra: None. A.S. Patel: None. S. Chauhan: None. A. Kumar: None. Relevance: Dried Blood Spot (DBS) technology has not been widely implemented in the diagnostic industry due to its limitations in obtaining reliable, quantitative data from small blood samples. However, recent advancements in methods, i.e., sensitive antibodies, homogeneous and reproducible paper quality, and painless needles have renewed the interest in the DBS collection technique. Objective: The aim of the study is to validate the hormone measurements using DBS technology and compare the correlation matrix between AMH, LH, FSH, inhibin B, Antral Follicle Counts (AFC), age, and BMI in patients seeking infertility workup. Materials and Methods: Matched serum and DBS samples from thirty-nine patients between the ages of 18 and 45 years were collected on day 3 of the cycle. The subjects were visiting the clinic for initial fertility workup and subjects on medications for ovarian suppression were excluded. The samples were tested on Ansh Labs DBS AMH (AL-129), FSH (AL-187), and LH (AL-190), PCOCheck AMH (N-N terminus, AL-196), picoAMH (C-N terminus, AL-124-r), US Inhibin B (AL-195) ELISAs. Baseline AFC obtained via transvaginal ultrasound, BMI, and age were collected. Spearman’s correlations, and regression analysis using Passing and Bablok were calculated to examine the relationship between AFC, AMH, inhibin B, FSH LH, age, and BMI. Results: DBS samples were highly correlated to their matched serum specimens. The slope and Spearman’s rank correlation (rs) between matched serum and DBS specimens for AMH, FSH, and LH were 1.17x, 1.07x, 1.07x, and 0.98, 0.93, and 0.97, respectively. DBS AMH strongly correlated with AFC. The Spearman’s rank correlation (rs) between AFC and DBS AMH, DBS LH, and DBS FSH were 0.80, -0.11, and -0.31, respectively. A strong correlation was observed between age and AMH, LH and FSH. A weak correlation was observed between BMI and AMH, LH and FSH. The Spearman’s rank correlation (rs) between age and DBS AMH, LH, and FSH were -0.34, 0.28, and 0.25, respectively. DBS AMH, LH, and FSH correlation with BMI were -0.06, 0.05, and 0.09, respectively. Inhibin B had a strong correlation to age (rs -0.33), BMI (rs -0.67), AFC (rs 0.44), DBS AMH (rs 0.40), DBS FSH (rs -0.19), DBS LH (rs-0.11), respectively. AMH method comparison between N-N and N-C terminal ELISA using 39 serum samples yielded slopes of 0.85x and Spearman’s rank correlation of 0.97. Conclusions: DBS and serum measurements for AMH, LH, and FSH are very accurate and precise. They can be used interchangeably. The strong relationship between BMI and Inhibin B will require further investigation and may open new avenues in obesity and reproductive endocrinology. Presentation: 6/1/2024

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-028 Evaluation of the Analytical Performance Iron3, Vitamin B12, and Homocysteine Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, mid-throughput integrated chemistry and immunoassay analyzer employing both Atellica® CH and Atellica® IM assays. This study evaluated the analytical performance of the Atellica® CH Iron3, and Atellica® IM Vitamin B12 (VB12) and Homocysteine (HCY) assays on the Atellica CI Analyzer. Methods The Atellica CI assays use the same reagents and calibrators as Atellica CH and Atellica IM assays. Precision studies followed CLSI EP05-A3; human contrived and serum samples were tested in duplicate in 2 runs per day for 20 days. Method comparison (MC) studies used human serum samples according to CLSI EP09c and EP09-A3. MC involved comparing the Atellica CH Iron3 Assay on the Atellica CH and Atellica CI Analyzers. MC also compared Atellica IM VB12 and HCY assays on the Atellica CI with Atellica IM Analyzer. Detection capability and linearity were determined. Results Representative precision and MC results are listed for each assay in the table. Slopes determined using the Deming linear regression model were approximately equal to 1. LoB, LoD, LoQ were 2, 4, 5 µg/dL (0.4, 0.7, 0.9 µmol/L) for Iron3, 45, 90, 90 pg/mL (33, 66, 66 pmol/L) for VB12, and 0.50, 1.00, 1.00 µmol/L for HCY; linearity was 5-1000 µg/dL (0.9-179.0 µmol/L), 45-2000 pg/mL (33-1476 pmol/L), and 0.50-65.00 µmol/L, respectively. Conclusions Atellica IM Iron3, VB12, and HCY Assays on the Atellica CI Analyzer demonstrated good precision and equivalent performance to the Atellica CH Analyzer.

A-101 Is That Unexpected? Education on Handling Real World Complications with Tightly Controlled Analytes During Method Evaluation

Abstract Background A common activity in clinical laboratories is performance evaluations. Given the importance for a new analyzer being put into clinical use, this exercise typically requires extensive preparation with significant time and resources invested to bring on new instrumentation. During early adoption, studies examined real-world performance and comparability of the Atellica® CI Analyzer (Atellica CI) to clinically used instruments. Precision, linearity, and method comparison (MC) studies, conducted in accordance with CLSI protocols, were completed at several locations installing new instruments to examine the analytical performance of common clinical laboratory assays. This work examines the impact of using only unmodified specimens to verify performance during method comparison for tightly controlled biological analytes like electrolytes and illustrates the impact of the tested sample range on regression analysis. Methods Testing was completed using unmodified, de-identified, remnant patient serum specimens. The MC studies for these electrolytes were completed over multiple days using single replicates from at least 40 individual specimens, on two instruments, the Atellica CI and the Dimension® EXL in accordance with CLSI EP09-3A. The effect of sample range on regression was demonstrated through data restriction and inclusion of modified sample results within the data analysis. Data analysis was completed using Analyse-it for Microsoft Excel (version 6.15.4). Results Representative method comparison data for sodium, chloride, and potassium found slope differences were more pronounced when sample concentrations were more limited. Individual assay slopes were determined using Deming linear regression model and comparisons between restricted samples show the effects of sample range on regression and correlation parameters. Conclusions Understanding the relationship between sample range and regression analysis is helpful to illustrate an important fundamental concept of method comparison. These examples illustrate the importance in covering as much of the analytical measuring interval as possible and the impact on regression analysis when samples are narrowly grouped.

A-053 Evaluation of the Analytical Performance of Atellica CH Prealbumin and β2-Microglobulin Chemistry Assays on the Atellica CI Analyzer

Abstract Background The Atellica® CI Analyzer is an automated, mid-throughput, integrated chemistry and immunoassay analyzer utilizing both Atellica® CH and Atellica® IM assays. This study was designed to evaluate the analytical performance of the Atellica® CH Prealbumin (PALB) and β2-Microglobulin (B2M) Assays on the Atellica CI Analyzer. Methods The Atellica CI PALB and B2M assays use the same reagents and calibrators as the Atellica CH assays. Precision and method comparison (MC) were used as performance indicators for the Atellica CI Analyzer. Precision studies were performed according to CLSI EP05-A3 using native, QC, 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. Method comparison (MC) studies were performed per CLSI EP09-A3. Individual serum samples were analyzed using the Atellica CH and Atellica CI Analyzers. Linearity and verification of detection capability studies were demonstrated for both assays. Results Representative precision, and MC results are presented in the table. Over the two assays tested, repeatability and within-lab %CVs were <4.0% and <4.6%, respectively. Slopes determined using the Deming linear regression model were approximately equal to 1. The Atellica CH PALB assay is linear from 3.0-70.0 mg/dL (30-700 mg/L); LoB, 1.1 mg/dL (11 mg/L); LoD. 1.9 mg/dL (19 mg/L); LoQ, 3.0 mg/dL (30 mg/L). The Atellica CH B2M assay is linear from 0.25-18.00 mg/L; LoB, 0.10 mg/L; LoD, 0.20 mg/L. Conclusions Atellica CH PALB and B2M Assays on the Atellica CI Analyzer demonstrated good precision and equivalent performance to the same assays on the Atellica CH 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-032 Evaluation of Assay Performance for Atellica CI 1900 analyzer in Routine Chemistry, Division of Laboratory Medicine, UMMC

Abstract Background The Atellica® CI 1900 (Siemens Healthiness) is a stand-alone, integrated clinical chemistry and immunoassay analyzer. Method verification has been done on this analyzer for 14 parameters based on the guideline of the Clinical and Laboratory Standard Institute (CLSI). Methods The method evaluation protocol consisted of determination of imprecision based CLSI EP 15-A3; CLSI EP06-A2 protocol was used for verification of linearity and method comparison was carry out in between Atellica® CI 1900 with our current Atellica® Solution based on CLSI EP09-A2 protocol. Method comparison data was analyzed by using statistical software, MedCalc. The data were used to calculate bias for Sigma metrics determination. Results Total of 14 analytes including sodium, potassium, chloride, creatinine, urea, alkaline phosphatase, total bilirubin, triglyceride, uric acid, glucose, thyroid stimulating hormone, free-thyroxine, human chorionic gonadotropin and carcinoembryonic antigen were tested. The results showed the repeatability and total imprecision were within acceptable limit as per manufacturer claims for all analytes. It was demonstrated that the analytical system operates within the claimed linearity ranges as stated in the information for use (IFU). Passing - Bablok analysis show the bias for all analytes were within our laboratory pre-set quality specification. The intercept and slope with 95% CI for Passing-Bablok analysis as shown in table 1. Sigma metrics were determined for each assay using the coefficient variation determined from precision study and bias obtained from the method comparison study. It showed that the Sigma for 14 analytes ranging from 3 to more than 6 with more than 93% assay has sigma scores more than 4. Conclusions Atellica® CI 1900 shows acceptable precision and bias for all analytes that evaluated. The analyser is fully comparable with Atellica® Solution. We conclude that Atellica® CI 1900 demonstrates good performance capabilities, making this analyzer suitable for low-to-medium volume laboratory.

B-258 Rapid clozapine blood levels on the Beckman Coulter DxC 500 AU

Abstract Background Clozapine is the most effective drug for treatment-resistant schizophrenia. Multiple guidelines strongly recommend clozapine therapeutic drug monitoring (TDM). Measuring clozapine blood levels provides essential information when there are questions of medication adherence, efficacy, toxicity, medication interactions, or concern over other factors that may influence clozapine levels. Turnaround time is essential for effective clinical decisions. However, with liquid-chromatography/mass spectrometry, clozapine levels can take days to report results. To address the medical need for a faster turnaround time, a rapid clozapine immunoassay was developed for automated clinical chemistry analyzers. The immunoassay measuring range is based on established APA Practice Guidelines and ASCP/AGNP Consensus Statement. We developed an analyzer application for the DxC 500 AU (time to first result < 9 minutes) to expand the availability of rapid clozapine blood level testing. Methods The performance of the FDA-cleared clozapine assay was evaluated on the DxC 500 AU according to CLSI guidelines. Precision testing was performed with three clozapine spiked pools over five days with five replicates per sample. Precision sample recovery was assessed to their theoretical spike concentration. Linearity was verified with five spiked serum samples covering the measuring range. Method comparison was performed with 40 remnant patient samples vs. the Beckman Coulter AU480. Results Repeatability CV was ≤5.5% and within-laboratory precision CV was ≤6.1%. Individual deviation was ±20% and mean deviation was ±2% for all samples. Deviation from linearity was <3%. Deming regression statistics for the method comparison were a slope of 0.987, an intercept of 5.7, and an R of 0.9948. The methods are statistically equivalent: the 99% confidence limits contained 1 and 0 for the slope and intercept respectively. Conclusions The precision, recovery, linearity, and method comparison results for clozapine on the DxC 500 AU demonstrate that the analyzer can be used to generate robust results for clozapine.

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.

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.

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-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.