bluuebunny/crossref_metadata_2025_split huggingface dataset:
A-104 Clinical Validation of the VITROS® Immunodiagnostics Products B·R·A·H·M·S PCT Test Medical Decision Points and Prediction of Cumulative 28-Day All-Cause Mortality
Authors: Ogbonna G , Ajongwen P , Alvey S 
Published: September 2023

Abstract

Background
Procalcitonin (PCT) is a biomarker for systemic bacterial infection and sepsis and may be used to aid in decision-making on antibiotic therapy for patients with suspected or confirmed lower respiratory tract infections (LRTI) and/or sepsis. Procalcitonin medical decision points have been established using the B·R·A·H·M·S PCT sensitive KRYPTOR assay. In this study, we compared the performance of the VITROS® Immunodiagnostic Products B·R·A·H·M·S PCT assay to the performance of the B·R·A·H·M·S PCT sensitive KRYPTOR assay at the established medical decision points. Percent change in PCT level over time can be used to aid in the prediction of cumulative 28-day mortality in patients diagnosed with severe sepsis and septic shock. The 28-day all-cause mortality prediction of the VITROS B·R·A·H·M·S PCT assay was also evaluated in the study.

Methods
Patient sample sets from the Multicenter Procalcitonin MOnitoring SEpsis (MOSES) study conducted in 13 sites in the United States were used in this study. Blood samples were collected on Days 0, 1, 3 and 4 from subjects who were admitted to the ICU with severe sepsis or septic shock. Each patient’s vital status was verified at Day 28. The samples were tested on the VITROS B·R·A·H·M·S PCT assay and the B·R·A·H·M·S PCT sensitive KRYPTOR assay. Concordance analysis between the VITROS B·R·A·H·M·S PCT and the B·R·A·H·M·S PCT sensitive KRYPTOR assays was performed at the established clinical decision points of 0.100 ng/mL, 0.250 ng/mL, 0.500 ng/mL, 2.00 ng/mL and 10.0 ng/mL to determine overall agreement between the two assays. For prediction of cumulative 28-day all-cause mortality using the VITROS B·R·A·H·M·S PCT assay results, the change in PCT values (Δ PCT) from Day 0 to Day 4 and Day 1 to Day 4 was calculated and evaluated against 28-day-all-cause mortality.

Results
Overall agreements of 98.5%, 98.0%, 97.4%, 97.8% and 98.0% were observed at 0.100 ng/mL, 0.250 ng/mL, 0.500 ng/mL, 2.00 ng/mL and 10.0 ng/mL, respectively, with the B·R·A·H·M·S PCT sensitive KRYPTOR assay. Δ PCT decline &gt;80% or ≤80% was significantly associated with 28-day-all-cause mortality (P = 0.006). Univariate Cox proportional hazards regression analysis showed a 1.93-fold increase in risk for mortality in subjects with a Δ PCT change ≤80%.

Conclusion
The VITROS B·R·A·H·M·S PCT assay demonstrated excellent agreement with the B·R·A·H·M·S PCT sensitive KRYPTOR assay at medical decision points used to aid in decision-making on antibiotic therapy for patients with suspected or confirmed LRTI and/or sepsis. Clinical performance shows ΔPCT information can be used to classify patients diagnosed with severe sepsis or septic shock as lower and higher risk for cumulative 28-day all-cause mortality.
A-105 Analytical Performance Evaluation of Four General Chemistry Assays on the Atellica CI 1900 Analyzer Used to Assess Kidney Function
Authors: Lewisch S , Tyler C , Kolewe K , Arrode-Bruses G , Rhea-McManus J , Snyder J 
Published: September 2023

Abstract

Background
The Atellica® CI 1900 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 Creatinine (CREA_2)*, Enzymatic Creatinine (ECre_3)*, Urinary/Cerebrospinal Fluid Protein (UCFP)*, and Microalbumin_2 (µALB_2)* assays on the Atellica CI 1900 Analyzer*.

Methods
The Atellica CI 1900 CH CREA_2, ECre_3, UCFP, and µALB_2 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 1900 Analyzer. Precision studies were performed according to CLSI EP05-A3 using native and contrived human urine samples. One aliquot of each sample pool was tested in duplicate in two runs per day &gt;2 h apart on each analyzer for &gt;20 days. MC studies were performed according to CLSI EP09-A3. Individual native and contrived human urine samples were analyzed using the Atellica CH assays on both the Atellica CH and Atellica CI 1900 Analyzers.

Results
Representative precision and MC results observed from one reagent lot across indicated sample ranges are listed for each assay in the table below. Over the four assays tested, repeatability and within-lab %CVs were &lt;5.1% and &lt;6.0%, respectively. Slopes determined by the Deming linear regression model were approximately equal to 1.

Conclusion
Evaluation of the Atellica CH CREA_2, ECre_3, UCFP, and µALB_2 assays using the Atellica CI 1900 Analyzer demonstrated good precision and equivalent performance compared to the same assays on the Atellica CH Analyzer.
*The products/features mentioned here are not commercially available in all countries. Their future availability cannot be guaranteed.
A-130 Analytical Performance Evaluation of Assays Measuring Acetaminophen and Ethanol on the Atellica CI 1900 Analyzer
Authors: Freeman J , Morjana N , Singh S , Arrode-Bruses G , Rhea-McManus J , Snyder J 
Published: September 2023

Abstract

Background
The Atellica® CI 1900 Analyzer is an automated, mid-throughput, integrated chemistry and immunoassay analyzer employing both Atellica CH and Atellica IM assays. This study was designed to evaluate the analytical performance of the Atellica CH Ethyl Alcohol (ETOH) and Acetaminophen (Acet) assays on the Atellica CI 1900 Analyzer.

Methods
The Atellica CI 1900 ETOH and Acet assays use the same reagents and calibrators as the comparable Atellica CH assays. Precision and method comparison (MC) were used as performance indicators for the Atellica CI 1900 Analyzer. Precision studies were performed according to CLSI EP05-A3. Native and contrived human serum samples were used. One aliquot of each sample pool was tested in duplicate in two runs per day &gt;2 h apart on each analyzer for &gt;20 days. MC studies were performed according to CLSI EP09-A3. Individual human serum samples were analyzed using the Atellica CH assays on both the Atellica CH and Atellica CI 1900 Analyzers. Precision and MC were evaluated with three reagent lots on one system.

Results
Representative precision and MC results observed for each assay are listed in the table. Over the two assays tested, repeatability and within-lab %CVs were &lt;2.5% and &lt;4.0%, respectively. Slopes determined by the Deming linear regression model were approximately equal to 1 for the ETOH and Acet assays.

Conclusion
Evaluation of the Atellica CH ETOH and Acet assays using the Atellica CI 1900 Analyzer demonstrated good precision and equivalent performance compared to the same assays on the Atellica CH Analyzer.
*The products/features mentioned here are not commercially available in all countries. Their future availability cannot be guaranteed.
A-143 Imaging Flow Cytometry: A Novel Method Using ADVIA 2120i System Reagents and Microscopic Image Analysis
Authors: Azhar M , Chakraborty I , Joshi A , Stelling F 
Published: September 2023

Abstract

Background
Flow cytometry based ADVIA 2120i Hematology System reagents are used to modify blood cells. Laser-scattering flow cytometry replaced with digital microscopic image analysis significantly simplifies the complex system to a compact, low-cost microscope. A novel method for imaging flow cytometry is proposed here that simultaneously generates complete blood count (CBC) and high-resolution images of blood cells.

Methods
Image processing algorithms are implemented to process the pixels containing blood cells. RBCs are made isovolumetrically spherical using the RBC reagent (Fig. 1A) and imaged. RBC volumes are easily determined from the diameter of the isovolumetrically spherical RBCs. By illuminating the spherical RBCs with approximately400 nm light, the increasing grayscale values of the pixels corresponds to increasing haemoglobin concentration due to absorption.
WBC nuclei are stained using the Perox reagent (Fig. 1B). The grayscale values of the nuclei pixels can be used to determine the peroxidase stain component, thereby obtaining cell size-to-peroxidase activity scatter plots similar to those on the ADVIA 2120i system. Using the Baso reagent, the cytoplasm of all WBCs are stripped off except for basophils, as shown in Fig. 1C. All the microscopic images have good contrast and high resolution. Image processing techniques can thus provide a 5-part differential using the nuclei/lobular density of WBCs.

Results
Images were obtained under a 20×x Nikon microscope with a Thorlabs DCC1545M monochrome camera. ADVIA reagents were mixed with venous blood and &lt;5 µL of reagent treated sample was spotted between a microscopic slide and coverslip. Image analysis was performed using ImageJ particle analysis tools.

Conclusion
Analysis of digital microscopic images of blood cells acted upon by ADVIA 2120i system reagents can offer a novel, simplified, cost-effective method of hematology analysis. Simultaneous CBC scatter plots and high-resolution images of the blood cells can be obtained using this new approach.Fig. 1.(a) Isovolumetricallly spherical RBCs, (b) peroxidase stain of WBC nuclei, and (c) cytoplasm of WBCs stripped off (except for basophils). Images taken under a 20× Nikon microscope. *Under development and not available for commercial sale.
A-170 Investigation of High Rate of Low Positive Quantiferon-TB Gold Plus Results
Authors: Mehreen A , Isidan K , Patel D B , Jones K , Laugesen M , Lee H 
Published: September 2023

Abstract

Background
Tuberculosis (TB) is a communicable disease, transmitted almost exclusively by cough aerosols carrying pathogens of the M. tuberculosis complex. TB continues to be a major public health threat, causing an estimated 10.4 million new cases and 1.3 million deaths from TB globally in 2016. Many more people may have latent tuberculosis infection (LTBI), which may go undetected without further laboratory investigation. The Quantiferon-TB Gold Plus (QFT-Plus) is an Interferon Gamma Release Assay (IGRA) for the identification of LTBI. It detects the cellular immune response to antigens of M. tuberculosis and represents an indirect marker of M. tuberculosis exposure. In January of 2021, the NorthShore University HealthSystem Core Laboratory transitioned from a reference laboratory ELISA-based QFT-Plus test to an in-house DiaSorin LIAISON® QuantiFERON®-TB Gold Plus test. After implementation, we noticed a higher rate of low positive QFT-Plus results (1.3%–5.4%) in our patient population that we regard as a mixed risk population. The expected percent of low positive results in a mixed risk population is 2%–3%.

Objective
To determine the potential causes of a higher rate of low positive Quantiferon-TB Gold Plus Results.

Methods
Forty specimens with Antigen-Nil results between 0.35–1.00 IU/mL using LIAISON® QuantiFERON®-TB Gold Plus reagent from 8/2022–10/2022 were collected for this study. All forty specimens were re-tested using ELISA-based methodology. Patient demographics and medical history were reviewed for any factor that may be responsible for the low positive results.

Results
Results from the two different methodologies were compared: 28/40 (70%) specimens showed positive results on the DiaSorin LIAISON®-XL platform, but negative results on the ELISA platform. Review of medical history showed that 92% of the sample population had received more than 2 doses of COVID-19 vaccine and 12.5 % had previous COVID-19 infection. 30% had an underlying autoimmune disease, with psoriasis and rheumatoid arthritis being the most common. However, no correlation was found between medical or vaccination history and the QFT-Plus results.

Conclusion
LIAISON® QuantiFERON®-TB Gold Plus is a Chemiluminescence immunoassay which is more sensitive than ELISA, resulting in an increased number of low positive QFT-Plus results. Physicians need to correlate clinical findings and TB exposure history to the QFT-Plus results when making clinical decisions.
A-184 Racing Against the Clock: Process Improvement Project to Reduce Cardiac Troponin Turnaround Time Through Autoverification of Results
Authors: Tauferner T M , Haga A J , Kelley B R , Wockenfus A M , Donato L J , Karon B S , Katzman B M 
Published: September 2023

Abstract

Background
Turnaround time (TAT), defined as time of collection to time of result verification, is monitored monthly for cardiac Troponin (cTnT). Within our STAT laboratory, our TAT goal is 85% of cTnT results verified within 45 min. In October 2021, our lab began observing an increase in TAT. A quality improvement project was launched to identify a root cause and possible solutions.

Methods
cTnT TAT data from the Hospital Clinical Laboratory (STAT lab) at Mayo Clinic, Rochester, MN was extracted from our Laboratory Information System (LIS) using Tableau (Salesforce Inc., Seattle, WA). The data were categorized into three components: collection time, in lab processing and testing time, and time to result verification. Goal metrics for each component are: collection &lt;10 min, in lab processing and testing &lt;25 min, and result verification to LIS &lt;5 min. The average time for each component and percentage not meeting TAT goals were calculated in Microsoft Excel. TAT while performing manual verification of results (January 2022) and after autoverification was implemented (December 2022) were compared.

Results
Prior to implementation of cTnT autoverification, total orders for January 2022 were 1408 with 82.0% meeting TAT of 45 min. Of the 18.0% not meeting TAT, 207 (14.7%) orders exceeded goals for one or more components (percentages do not total 100%): collection delays 131 (63.0%), in lab processing and testing delay 175 (85.0%), and delay in result verification to LIS 80 (39.0%). For those orders not meeting the 45 min TAT goal, mean times were 17.6, 40.3, and 8 min for collection time, in lab processing and testing, and result verification to LIS, respectively. Post implementation of autoverification, total orders for December 2022 were 1444 with 88.6% meeting TAT of 45 min. Of the 11.4% not meeting TAT, 93 (6.4%) orders were outside goals for multiple components: collection delays 51 (55.0%), in lab processing and testing delay 67 (72.0%), and result verification to LIS 0 (0.0%) orders. For those orders not meeting the 45 min TAT goal, mean times 16.6, 39.7, and 0 min for collection time, in lab processing and testing, and result verification to LIS, respectively.

Conclusion
Achieving TAT goals agreed upon by the laboratory and clinical practice is critical to quality patient care. An investigation into our delayed TAT for cTnT highlighted several opportunities for intervention within the control of the lab. We chose to implement autoverification of results to easily and consistently eliminate the time required for manual result verification. TAT was improved by 6.6% (82.0% to 88.6%) through autoverification of results, allowing technologists to focus on other clinical work.
A-203 An Equation based on the Standard Lipid Panel for Calculating Low-Density Lipoproteins-Triglycerides
Authors: Wolska A , Sampson M , Meeusen J W , Donato L J , Jaffe A S , Remaley A T 
Published: September 2023

Abstract

Background
There is growing evidence that low-density lipoprotein-triglyceride (LDL-TG) may be a better biomarker to define atherosclerotic cardiovascular disease (ASCVD) risk than LDL-cholesterol (LDL-C), which is currently used to stratify risk and as a treatment goal. Because LDL-TG typically requires additional advanced lipid testing, we developed an equation for estimating LDL-TG (eLDL-TG) from the results of the standard lipid panel.

Methods
Results from a general dyslipidemic population (N = 40 202), which were obtained with beta-quantification (BQ) reference method, were randomly divided into a training and validation datasets and used to develop the equation for estimating LDL-TG shown in Fig. 1A. Association of Sampson-NIH-LDL-C (NIH-LDL-C) and eLDL-TG with ASCVD risk markers was done in the National Heart and Nutrition Examination Survey (NHANES) (N = 37 053) and with ASCVD events in the Atherosclerosis Risk in Communities (ARIC) study (N = 14 749).

Results
The comparison between eLDL-TG and measured LDL-TG was only modest (R2 = 0.601, slope = 0.611), but eLDL-TG (Fig. 1B) showed better risk stratification than NIH-LDL-C (Fig. 1C) by survival curve analysis in ARIC. Moreover, receiver-operating characteristic (ROC) analysis showed that eLDL-TG was better than all other lipid-marker tests for ASCVD events (AUC: eLDL-TG = 0.633, HDL-C = 0.627, sdLDL-C = 0.621, remnant-cholesterol = 0.613, NonHDL-C = 0.613, TG = 0.603, apoB = 0.598, NIH-LDL-C = 0.590, TC = 0.568). In NHANES, eLDL-TG was more strongly associated with hypertriglyceridemia, obesity, diabetes, metabolic syndrome and increased high-sensitivity C-reactive protein than NIH-LDL-C. Inclusion of eLDL-TG in a Cox-Proportional Hazards Model along with other conventional risk factors (age, sex, race, diabetes, systolic blood pressure, smoking, HDL-C, and total cholesterol) did not further improve risk prediction.

Conclusions
Like LDL-C, LDL-TG can also be estimated from the results of the standard lipid panel. It is a better univariate risk marker than LDL-C and hence can be useful for initial ASCVD risk stratification.
A-231 Prediction of Severe COVID-19 Based on Routine Biomarker Assessment
Authors: Kapoor H , Bi C , Salm A E , Szymanski J , Goldstein Y D , Wolgast L R , Rosenblatt G , Fox A S , Kroll M H 
Published: September 2023

Abstract

Background
Disease courses in COVID-19 patients vary widely. Prior studies did not focus on initial values of various laboratory biomarkers, instead used data throughout the disease course. Prediction of disease severity based on parameters at the initial diagnosis would aid appropriate management. Objective of our study was to develop predictive models of COVID-19 severity based on demographic, clinical, and laboratory data collected at initial patient contact after diagnosis of COVID-19.

Methods
We evaluated de-identified demographic, clinical, and routine biomarkers data from 14 147 patients with COVID-19 diagnosed by polymerase chain reaction SARS-CoV-2 testing at Montefiore Health System from March 2020 to September 2021. We generated models predicting severe disease (death or more than 90 hospital days) vs mild disease (alive and fewer than 2 hospital days), starting with 58 parameters, by backward stepwise logistic regression.

Results
Of the 14 147 patients, 18% had severe, 24% had mild outcomes and the rest were moderate (cases who were alive but in the hospital for 2–89 days). We identified 4 proficient models in predicting patient outcomes: Inclusive model A, with the largest number (37) of parameters; Receiver Operating Characteristics (ROC) Model B, including 9 parameters with the highest Area under Curve (0.85); the Specific Model C, including 10 parameters with the highest specificity (81%) and Positive Predictive Value and the Sensitive Model D including 9 parameters with the highest sensitivity (91%) and Negative Predictive Value (Tables 1 and 2). The parameters that remained in all models were age, albumin, diastolic blood pressure, ferritin, lactic dehydrogenase, socioeconomic strength, procalcitonin, b-type natriuretic peptide, C reactive protein, d dimer and platelet count.

Conclusions
These findings suggest that certain clinical parameters and routine laboratory biomarkers within the specific and sensitive models could benefit healthcare providers, in their assessment of disease severity and clinical management of COVID-19 infection.
A-266 Evaluation of an Antibody Index Assay for Assessment of Intrathecal Anti-Treponema pallidum IgG Synthesis for the Diagnosis of Neurosyphilis
Authors: Granger D , Theel E S 
Published: September 2023

Abstract

Background
Diagnosis of neurosyphilis (NS) is challenging due to nonspecific clinical symptoms and the lack of a sensitive and specific laboratory test. The non-treponemal Venereal Disease Research Laboratory (VDRL-CSF) assay is a commonly used test in diagnosing NS. An important limitation of the VDRL-CSF is limited specificity, in part due to the inability to differentiate between intrathecally produced antibodies vs passive antibody diffusion into the CSF due to blood-brain barrier (BBB) disruption. Here, we compared the intrathecal synthesis antibody index (AI) of anti-Treponema pallidum IgG antibodies to results from the VDRL-CSF assay in routinely submitted clinical samples for evaluation of suspected NS.

Methods
Paired serum and CSF residual clinical samples from 98 patients with previous VDRL-CSF results were collected. For each pair, the serum and CSF were drawn within 24 h. No additional clinical information and limited supporting clinical test results were available. Thirty-one positive and 67 negative paired samples were tested by an anti-T. pallidum IgG ELISA (Euroimmun, Lübeck, Germany). The AI was calculated using Reiber’s method, with intrathecal total IgG synthesis corrected using the Reiber recommended albumin quotient calculation. Results were compared for positive, negative and overall agreement between methods.

Results
The anti-T. pallidum AI showed a positive, negative and overall agreement of 71.0% (22/31), 100% (67/67) and 90.8% (89/98), respectively, compared to VDRL-CSF. Of note, all nine discordant samples showed abnormally elevated albumin levels in CSF (range: 27.4 to 215 mg/dl; median = 41.7 mg/dl; normal value =&lt;27 mg/dl), indicating a compromised BBB which likely resulted in false-positive VDRL-CSF results. The range and median value for CSF albumin in the 22 concordant samples was 12.4 to 168 mg/dl and 37.2 mg/dl, respectively. In total, 83.9% (26/31) of VDRL-CSF positive samples showed elevated CSF albumin levels which suggests a high percentage of BBB impairment in this patient population. This demonstrates the advantage in specificity that is offered by AI testing compared to use of the VDRL-CSF assay, given the ability of AI to differentiate intrathecally produced vs passively diffused syphilis-specific antibodies. No potential increase in sensitivity was observed in AI testing as 100% negative agreement was obtained.

Conclusion
Our data suggests that establishment of an AI using a treponemal assay to detect intrathecal antibody synthesis provides improved specificity compared to the current commonly performed VDRL-CSF antibody test as an aid in the diagnosis of NS. Further evaluation of sensitivity is warranted using samples from patients with clinically diagnosed NS.