bluuebunny/crossref_metadata_2025_split huggingface dataset:
A-329 Preliminary Clinical Method Comparison of a Near-Patient Platform for Low Blood Volume Testing of aFXa in Pediatric Patients on Heparin Therapy
Authors: Aljudi A , Lam W , Sista R , Pamula V , Rogers B 
Published: September 2023

Abstract

Background
Up to 15% of hospitalized children receive heparin therapy and require frequent monitoring for Anti-Factor Xa activity (aFXa) and activated partial thromboplastin time (aPTT) to achieve hemostatic balance. Current heparin tests require large blood volumes, which can lead to iatrogenic anemia with frequent sample collection. We performed a small clinical method comparison of a rapid, near-patient platform for simultaneous whole blood testing of aFXa from 50 μL of sample against the clinical standard test. The aPTT assay is in development on the same digital microfluidic (DMF) platform.

Methods
Four DMF instruments were placed in our laboratory. Preliminary precision of the DMF aFXa assay was obtained using commercial controls (n = 19 for aFXa at 0.98 U/mL; n = 20 for aFXa at 0.42 U/mL). We obtained whole blood or plasma from residual aFXa samples from pediatric patients. Venous samples were collected from patients for routine testing in the core laboratory, and 150 μL of whole blood was saved for aFXa method comparison testing. Patients were either on low molecular weight heparin or unfractionated heparin. We performed a method comparison study to determine assay equivalence to in-house clinical standard tests using plasma for aFXa on the Stago STA R MAX to both plasma and whole blood on the DMF platform.

Results
For precision, we observed an assay coefficient of variation (CV) of 4.68% and 6.6% for aFXa at 0.98 U/mL and 0.42 U/mL, respectively. The aFXa assay correlated well (R2 = 0.94 for whole blood (n = 9) and R2 = 0.97 for plasma (n = 10)); additional studies are needed to demonstrate aPTT assay equivalence.

Conclusions
We demonstrated good correlation of the DMF aFXa assay to the clinical standard test. The low blood volume requirement make these tests suitable for use in heparin monitoring where frequent testing is necessary. A large scale clinical method comparison is planned to ensure clinical utility.
A-332 Sweat rate does not influence sweat chloride concentration
Authors: Omosule C , Roper S 
Published: September 2023

Abstract

Introduction
The recommendations for sweat chloride ([Cl-]) testing from the Clinical and Laboratory Standards Institute (CLSI C34-A4 2019) endorse a minimum sweat rate of 1g/m2/min to validate efficient sweat stimulation. For labs that use macroduct ® collection devices, this rate corresponds to a sweat volume ≥15 µL collected within a 30-minute period. Bilateral collection and testing is also advised to improve the odds of obtaining a sufficient specimen from at least 1 site. When both sites fail to meet the minimum rate, the test is invalid (QNS) and should be repeated, potentially delaying Cystic Fibrosis (CF) diagnosis. In this study, we evaluate the premise for the minimum sweat rate by investigating the relationship between sweat rate and [Cl-]. In a sub-analysis, residual sweat available after clinical testing is used to examine the effect of specimen pooling on [Cl-]. This study has the potential to inform best practices for future sweat testing guidelines, decrease QNS rates, and reduce time to CF diagnosis.

Methods
Thirteen months of data from sweat tests performed at St. Louis Children's Hospital were reviewed. All collections were performed using macroduct devices following CLSI 34-A4 guidelines (results from QNS specimens were not reported clinically). Pearson correlation was calculated to examine the relationship between sweat rate and [Cl-] (n = 354). Deming regression was applied to evaluate the effect of specimen pooling, versus results from individual sites, in 19 collections with residual volume after clinical testing.

Results
Figure 1

Conclusion
Negligible correlation between rate and [Cl-] across a wide range of values suggests the current minimum volume for macroduct collections (15 µL) may be overly stringent. Reporting of [Cl-] in specimens with ≥10 µL sweat may decrease QNS rates without compromising accuracy. Preliminary data suggests pooling of bilateral collections may be a feasible option to achieve the minimum volume required for testing (10 µL).
A-349 Septec: A Microfluidic Platform for the Rapid Diagnosis of Bloodstream Infection Diagnosis and Associated Sepsis Management
Authors: McArdle H , Cassedy A , Adamson K , Burke D , Farghaly Mohammed A , McEvoy N , Smyth M , Curley G 
Published: September 2023

Abstract

Background
Sepsis is a life-threatening disorder resulting from a dysregulated host response to infection. Globally, sepsis is responsible for 11 million deaths annually and is associated with high mortality and morbidity. Sepsis can arise from any infection by microbes or viruses; however, the most common cause is bloodstream infection (BSI) via bacterial pathogens. Rapid identification of organisms responsible for BSI may reduce time until the administration of suitable antibiotics and employment of rapid diagnostics at patient bedside further strengthens their value as informed clinical decisions can be made and acted upon within shorter timeframes, potentially enhancing patient outcomes and preventing progression to more critical sepsis or septic shock. This study reports on the analytical and clinical performance of the SepTec microfluidic assay, an in-vitro diagnostic device capable of rapid detection of bloodborne pathogens of gram-positive, gram-negative and fungal origin from whole blood within 15 minutes.

Methods
Analytical performance of the SepTec assay was studied as follows: limit of detection (LoD), reproducibility and impact of interfering substances. Sterile and infected blood samples were obtained either through the generation of contrived samples or through clinical collaboration. Clinical performance was determined retrospectively and prospectively on a total of 146 patients. For both the retrospective and prospective clinical studies, results were compared against blood culture.

Results
The LoD of the SepTec assay for S. Aureus, E. coli and C. albicans from contrived blood samples was 10 CFU/mL for each pathogen. CVs were calculated at 4% for organism detection in whole blood samples. From retrospective and prospective analysis, the SepTec assay showed 100% sensitivity and &gt;96% specificity.

Conclusion
The SepTec assay can detect microbes from blood and differentiate between gram-positive, gram-negative or fungal pathogens with high sensitivity and specificity. Turnaround time for the test is estimated at 15minutes, rendering it with the potential to be a significantly more rapid approach than the gold-standard blood culture, or many molecular approaches. It is hoped that this work with yield a point-of-care diagnostic platform which will enhance sepsis management, overall improving patient outcomes.
A-371 Comparative Evaluation of POCT Based Lysophosphatidylcholine Measurement
Authors: Rim J , Choi H , Jang H , Jang J , Kang H , Lim J 
Published: September 2023

Abstract

Background
Lysophosphatidylcholine (LPC), also referred to as lysolecithin, is a phospholipid intermediate whose concentrations have been correlated with such diseases as cancer, artherosclerosis and diabetes. Recently, serum LPC concentrations have been reported to be candidate biomarker for bacterial infection and sepsis. In this study, we evaluated the comparative performance of the point-of-care test (POCT) measurement of LPC using CareBuddy Multi Analyzer.

Methods
A total of 120 serum samples were analyzed for LPC by enzymatic spectrophotometry (CareBuddy Multi analyzer, CareBuddy catridge) and mass spectrometry based method (TSQ Altis LC/MS/MS) as the reference method. Additionally, subset of samples with enough remnant volumes were assessed for PCT and CRP using electrochemiluminescence immunoassay (Roche Cobas e801, Roche Elecsys BRAHMS PCT) and immunoturbidimetric assay (Roche Cobas c702, Sekisui Nanopia CRP), respectively. The equivalence and correlation among the methods were evaluated using linear regression analysis.

Results
The LPC measurement by POCT analyzer showed high correlations with the LC-MS based reference method (y = 1.02x + 1.26). The LPC measurement by POCT showed correlation coefficient for PCT (Pearson's r = −0.316) and CRP (Pearson's r = −0.618). Upon applying clinical cutoffs for qualitative result, LPC POCT measurement showed good agreements to each reference methods.

Conclusion
In summary, our results suggest that the quantitative measurement for LPC via POCT device in human serum samples possess possible clinical feasibility as a novel sepsis biomarker.
A-373 Comparison of the CoaguChek ® and Coag-Sense ® PT2 Meter Point of Care INR Devices
Authors: Schumann T , Karon B , O'Connor C , Jennifer L , Blanco J , Hartman L , Kramer A , Uy J , Myhre N , Gayle D , Hartung K , David H , Santrach P , McBane R 
Published: September 2023

Abstract

Background
Warfarin monitoring may be done at the point-of-care (POC) at home, in a clinic environment, or be performed using plasma specimens in a central laboratory. With a goal of standardizing International Normalization Ratio (INR) measurements and improving data integrity by enabling electronic transmission of results from any location, we evaluated two POC INR devices against an internal plasma INR reference method.

Methods
We conducted a multicenter study to test the accuracy of two commercially available point of care devices: Coag-Sense PT2 Meter (Coagusense, Inc., Fremont, CA) and CoaguChek XS Pro or XS Plus (Roche Diagnostics, Indianapolis, IN) compared with plasma INR values among warfarin treated patients. Bias and linear regression analysis were assessed for device-plasma INR comparisons. Warfarin dosing decisions were assessed for each device compared to an internal plasma INR reference method (Instrumentation Laboratories ACLTOP 500, 550, 750 analyzers (Werfen Diagnostics, Bedford MA) in one of three CLIA-certified laboratories. The thromboplastin used at our institution for INR measures is HemosIL RecombiPlasTin 2G (R2G) reagent (Werfen Diagnostics, Bedford MA) which has an International Sensitivity Index (ISI) of 1.0.

Results
Two hundred ninety-nine warfarin patients treated across three Mayo Clinic sites agreed to participate in the study. Common anticoagulant indications were atrial fibrillation (63.9%), venous thromboembolism (21.7%) and heart valve prosthesis (15.4%) with a 2.0–3.0 INR target range for 93.6% of patients. For the CoaguChek devices, 81.3% of values fell within 0.2 INR units of plasma INR referent and 95.3% within 0.4 units. The correlation between CoaguChek whole blood and plasma INR was excellent (R2 = 0.93). For the Coag-Sense device, 34.1% of values fell within 0.2 INR units and 60.2% within 0.4 INR units of plasma INR values, with a slightly weaker correlation between Coag-Sense whole blood and plasma INR (R2 = 0.83; P &lt; 0.0001). Mean (± standard deviation) deviation from plasma INR was 0.04 ± 0.2 for CoaguChek compared to 0.4 ± 0.3 for Coag-Sense (P &lt; 0.0001). The difference between POC devices was largely attributed to systematic negative bias between Coag-Sense and ACL TOP plasma INR values. Using the plasma INR as the reference method for dosing decision making, appropriate dosing recommendations would have occurred for 97.7% of CoaguChek and 81.6% of Coag-Sense results.

Conclusion
Compared to our institution's plasma reference method, INR values obtained from the CoaguChek devices (XS Pro and XS Plus) exhibited less systematic bias compared to the Coag-Sense values. This translates to greater percentage of concordant management decisions between POC and laboratory plasma INR methods when the CoaguChek device is used.
A-377 The Selection and Implementation of POC Illicit Drug Toxicology Testing in Hamad Medical Corporation - Doha, Qatar
Authors: Al Kuwari E , Al-Wali D , Habib J S , Kabir Z , Abdelfadel A , Torato E , Dellil A 
Published: September 2023

Abstract

Background
In 2013, Qatar launched the National Mental Health Strategy which is further supported by National Health Strategy 2018–2022 and Qatar National Vision 2030, where the mental health has been identified as a priority area of development. In doing so, the Ministry of Public Health worked closely with the Ministry of Interior in providing the appropriate treatment rehabilitation. With all considerable advantages of point-of-care testing (POCT) in rapid diagnosis, POC toxicological test has been implemented and used in screening of patients for drugs of abuse. In this study, we highlighted the challenges in selection and implementation process of POC toxicological test in Hamad Medical Corporation (HMC).

Methods
Due to unavailability of all required drug panels, it had to be customized and tested for the verification purpose before starting the evaluation process. Maintaining HMC procurements regulations and Clinical Laboratory Improvement Amendments (CLIA) and College of American Pathologist (CAP) standards for POC toxicology tests, two POC illicit drug toxicology screening tests has been evaluated, comparison study has been performed against the HMC central laboratory. POCT team conducted training session ensuring the appropriate practice in place. The Extendable Laboratory Information System (LIS) functionality has been utilized for seamless data management and reporting for the automated analyzer.

Results
QUIDEL triage meter pro is an automated drug testing analyzer which detects Amphetamines, Barbiturates, Benzodiazepines, Cannabinoids, Methadone Metabolite, Methamphetamine, Opiates, Tricyclic and Cocaine Metabolites, while the customized manual testing kit FASTEP detects Tramadol (TRA), Methylenedioxymeth-amphetamine (MDMA), Phencyclidine (PCP), Buprenorphine (BUP), Oxycodone (OXY), Fentanyl (FYL), Ethyl Glucuronide (EtG), Cotinine (COT), Pregabalin (PGB) and Gamma Hydroxybutyrate (GHB). Both analytical performances were verified. Rapid bedside testing performed for more than 100 patients in last 8 months during admission, observation, and pre- discharge process. There is An Obvious improvement observed in testing turnaround time compared to the laboratory, easy results interpretation and reporting as well as cost-effective.

Conclusion
The implementation of POC illicit drug toxicology testing in HMC aligned with core pillars of the Qatar vision 2030 to deliver the right treatment at the right time and place. Its enhancing patient outcomes and overall Satellite health care sector in Qatar.
B-011 Analytical Validation of a New Vasoactive Intestinal Peptide Radioimmunoassay
Authors: Ashrafzadeh-Kian S , Bornhorst J , Algeciras-Schimnich A 
Published: September 2023

Abstract

Background
Vasoactive intestinal peptide (VIP), a potent vasodilator, is produced by neuronal cells located in the central nervous system, the digestive, respiratory, and urogenital tracts, and the exocrine, thyroid, and adrenal glands. Increased circulating VIP is clinically useful to detect VIP-producing tumors in patients with chronic diarrheal diseases.

Objective
Develop a sensitive replacement radioimmunoassay (RIA) for VIP quantitation in human plasma due to the diminished supply of the antibody used in the previous in-house method.

Method
Patient VIP in EDTA plasma competes with labeled (125I) VIP for a limited number of primary rabbit polyclonal antibody (BMA Biomedicals, Augst, Switzerland) binding sites. Antibody-bound VIP is then complexed with a goat anti-rabbit secondary antibody and precipitated out of the solution with the use of polyethylene glycol and centrifugation. After the supernatant is discarded, the 125I signal from the pellet is counted on the Wizard2 gamma counter (Perkin Elmer, Waltham, MA). The measured signal is inversely proportional to the amount of VIP present in the patient’s sample. Method validation of the new assay included determination of imprecision (pooled human EDTA plasma), limits of detection and quantification, analytical measurement range (AMR), accuracy by spike recovery, interferences, cross-reactivity, stability, reference interval determination, and agreement with the current Mayo laboratory-developed assay.

Results
Stability studies on freshly collected EDTA plasma showed VIP is stable for 3 days ambient, 7 days refrigerated, and 14 days frozen. Intra-assay imprecision studies showed 8.3, 2.3, and 1.3%CV for mean VIP concentrations of 41, 144, and 304 pg/mL. Inter-assay imprecision was 12.9, 7.6, 5.2, and 7.5%CV for mean VIP concentrations of 30, 81, 180, and 308 pg/mL. The assay limit of detection was 29 pg/mL. The limit of quantitation was 30 pg/mL (%CV = 13%) and was established via precision profile. The AMR was 30–500 pg/mL (slope of 0.98, intercept of 3.0 pg/mL, and R2 of 0.97). The mean % spike recovery using a different preparation lot of calibrator material was 89% (range 83%–93%). The assay was not affected by up to 1000 mg/dL hemoglobin, 1000 mg/dL triglycerides, or 10 mg/dL bilirubin. Peptide histidine methionine 27, neurotensin, gastric inhibitory peptide, motilin, secretin, and glucagon do not cross-react in the assay. The 97.5th reference limit was &lt;86 pg/mL (95% CI 81–90, n = 127). Positive percent agreement (PPA), negative percent agreement (NPA), and overall percent agreement (OPA) with the current Mayo VIP assay were 97, 82, and 90% respectively.

Conclusion
We have developed a replacement VIP RIA. This assay has a lower limit of quantitation and a broader AMR than the current assay. Concordance with the current assay was acceptable.
B-020 Fully Automated and Scalable cfDNA Extraction Solution from up to 10 mL Samples
Authors: Lysen J , Baggs J , Butts T , Durvasula K 
Published: September 2023

Abstract

Background
The use of circulating, cell-free DNA (cfDNA) is rapidly evolving in the clinical landscape, becoming one of the fastest growing areas in recent years. It offers tremendous clinical potential as a screening method for tumor, cancer, disease progression, treatment response, and more. Circulating DNA is found in low quantities and often requires large sample input volumes to isolate the less abundant cfDNA to sufficient amounts needed for downstream analysis. The existing methods for extraction are often silica spin column-based, which involve an extensive amount of hands-on work, and they require large volumes of binding buffers, making it unsuitable for extractions involving sample volumes as large as 10 mL. These existing workflows impose certain limitations in terms of the sample volume and number of samples that they can process.

Methods
To tackle this necessity, Omega Bio-tek has developed a fully automated solution using Mag-Bind® cfDNA Kit (M3298) to extract cfDNA from up to 10 mL volumes from 48 samples in 2.75 h when integrated on Hamilton’s Microlab® STAR™ platform.

Results
The system is scalable and can extract from sample volumes ranging from 1–10 mL without any hardware modification or additional, expensive accessories on the Hamilton workstation. Here, we elucidate the workings of this automated protocol using Omega Bio-tek’s Mag-Bind® cfDNA Kit and compare its performance to a manual extraction protocol from 4 mL of plasma processed using the same kit. We also present additional solutions using the Mag-Bind® cfDNA kit to showcase extraction of fragments as small as 50 bp with minimal genomic DNA contamination.

Conclusion
Omega Bio-tek’s custom workflows provides the customers with different protocols to fit their different application needs. Thus, this kit offers researchers and scientists the flexibility to use the same kit for not only large volume sample processing but also for recovering short cfDNA fragments.
B-034 Evaluation of the Analytical Performance of Sebia CAPI 3 HbA1c Assay
Authors: Laryea E T , Bates M , Fan S 
Published: September 2023

Abstract

Background
HbA1c has been the most important marker for glycemic control and for the diagnosis of diabetes mellitus. The NGSP has invested significant efforts in the standardization of the HbA1c assays, and several analytical methods have been developed. We evaluated the analytical performance of the Sebia CAPI 3 HbA1c assay, which is determined by capillary electrophoresis. Additionally, samples with and without hemoglobin variants are analyzed, and results are compared to two HPLC-based methods.

Methods
Control materials are used in the precision study, which are included in the Sebia CAPI 3 HbA1c kit (Lisses, France). Linearity study is assessed with the linearity materials from LGC Maine Standards (Cumberland Foreside, ME). Carryover is determined by the EP Evaluator (Colchester, VT) with total 21 aliquots of a high and a low HbA1c sample assayed in a specific order. Accuracy study is determined by whole blood patient samples without hemoglobin variants (n = 40) and with hemoglobin variants (n = 8, mostly with Hb S of 30–40%). Results from Sebia CAPI 3 are compared to the current laboratory method (BioRad Variant II Turbo) (Hercules, CA) and the TOSOH G8 (Tokyo, Japan). Both are HPLC-based methods.

Results
The within-run precision at a mean of 5.5% HbA1c has a CV at 1% (n = 24), and the between-run precision at the level of 5.5% and 8.7% HbA1c has a CV at 1% (n = 20) and 2% (n = 20), respectively. Linearity study demonstrates the analytical measuring range is between 3.1% and 20.8%, although each laboratory might establish its own clinical reportable range. Carryover is passed based on the automatically calculated error limit in EP Evaluator (3 times the SD of the Low-Low results). The accuracy study shows the Sebia results correlate well with percent bias at 2% for BioRad Variant II Turbo and 3% for TOSOH G8 in samples with (n = 8) and without (n = 40) hemoglobin variants.

Conclusion
The Sebia CAPI 3 HbA1c assay is based on capillary electrophoresis principle, which is a recognized method by NGSP. The assay has demonstrated good precision, a wide analytical measuring range and minimum carryover. The results are comparable to two HPLC-based methods and are well within the total allowable error of 6% by NGSP in samples with and without hemoglobin variant.