bluuebunny/crossref_metadata_2025_split huggingface dataset:
B-098 Clinical comparison of five assays for the detection of anti-dsdna antibodies and their correlation with complement consumption
Authors: Ricchiuti V , Obney J R , Holloway B , Aure M , Mahler M 
Published: October 2024

Abstract

Background
Anti-dsDNA antibodies are highly specific and part of the classification criteria for systemic lupus erythematosus (SLE). They correlate with disease activity and contribute to the pathogenesis of lupus nephritis (LN). This study aimed to compare five methods for anti-dsDNA antibody detection and to estimate their association with complement consumption.

Methods
186 samples were collected at Labcorp and tested on five assays: Crithidia luciliae indirect immunofluorescence test (CLIFT, Euroimmun, Lübeck Germany), BioPlex 2200 dsDNA (BioRad, Hercules, US), QUANTA Lite HA dsDNA ELISA, QUANTA Flash dsDNA chemiluminescent immunoassay (CIA), and Aptiva dsDNA, a particle-based multi-analyte technology (PMAT) immunoassay (all 3 assays, Inova Diagnostics, USA). Complement C3 and C4, measured with Cobas c 502 (Roche Diagnostics, USA), were used as serological surrogates and compared to each assay to assess the correlation with disease activity.

Results
The quantitative agreement varied between 0.60 (BioPlex vs. CLIFT) and 0.96 (Aptiva vs. QUANTA Flash) (Table 1). The C3 agreement from highest to lowest was: HA dsDNA ELISA, CLIFT, QUANTA Flash, Aptiva, then BioPlex 2200. The findings were compared to qualitative results derived from CLIFT testing, since CLIFT is often used as the confirmation assay for anti-dsDNA. The highest area under the curve (AUC) from the receiver operating characteristic (ROC) curve was found for QUANTA Flash (0.95) followed by Aptiva and HA ELISA (both 0.94) and then BioPlex (0.87).

Conclusions
Anti-dsDNA antibodies measured using different methods showed varying agreement with CLIFT and complement consumption. Aptiva and QUANTA Flash dsDNA were highly correlated and in strong concordance with low C3 levels.
B-114 Reference interval (RI) estimation for TSH in adults using an indirect method with unsupervised machine learning tool and R programming language
Authors: Meira Dias C , Correa Wengerkievicz Lopes A , Grando Remor Canali D , Falci Vieira L M , de Souza Santos B , Goetz Muller K , de Oliveira Weingrill Sabino C 
Published: October 2024

Abstract

Background
Thyroid-stimulating hormone (TSH) plays a fundamental role in regulating thyroid hormones T3 (triiodothyronine) and T4 (thyroxine). Understanding TSH test results is essential for effective management of thyroid disorders and depends, among other factors, on establishing specific reference intervals (RI) for the population being served. We aimed to estimate the reference intervals for TSH in the adult population served by a large diagnostic network in Brazil.

Methods
We employed data mining followed by estimation using an indirect method through the LabRI™ algorithm with parametric, non-parametric, and robust statistical treatments for outlier exclusion, a series of algorithms programmed in R Language. Included were TSH values from outpatients, aged 20 to 60 years, both sexes, from two analytical platforms. Used as a comparative RI recommended by the American Thyroid Association (ATA, 2014). Data were extracted from the Data Lake, from January to December 2022, from two laboratories in Brazil. Exclusion criteria: samples from hospital sources and referral laboratories; pregnant; some laboratory tests correlated with de TSH test; samples from patients using thyroid hormone and medications that may interfere with hormonal function and TSH laboratory analysis.

Results
After exclusion criteria, the sample totaled 26,909 adults of both sexes. After excluding 2.24% outliers, the estimated RI was 0.67-4.26 mIU/L, with the comparative RI chosen for this study being the one recommended by ATA of 0.40-4.00 mIU/L. The RI obtained in our study was similar to the Canadian RI harmonization study for TSH (0.60-4.48 mIU/L).

Conclusions
We estimated the RI, harmonized between Roche and Siemens platforms, to be 0.67-4.26 mIU/L. The RI obtained by the LabRI™ tool is equivalent to the Adeli study (2023) and is under discussion by the company's endocrinology committee for whether to use the estimated RI from our internal study or the one recommended by ATA (2014) in reports.
B-135 Evaluation of Verification Decision Limits (VDL) for Routine Coagulation Post-Analytical Review: A Preliminary Analysis
Authors: Limpornpugdee O , Tanticharoenkarn S , Limprapassorn P , Prompetchara E 
Published: October 2024

Abstract

Background
A major challenge faced by medical laboratories is to meet the demand for high-throughput laboratory analysis while maintaining the quality and accuracy of the results. Manual validation remains an obstacle, with increased workloads for medical technologists leading to delayed results. The purpose of the study is to evaluate and implement VDL for routine coagulation automated post-analytical review system.

Methods
The study was conducted in the Division of Laboratory Medicine, King Chulalongkorn Memorial Hospital, Thailand. Our coagulation assay consists of activated partial thromboplastin time (APTT), and prothrombin time (PT). The VDL was a population-based percentile calculation, excluding the outlier using the Tukey method and incorporated with reference values. The decision range was implemented in the post-analytical review of the LIS system. The evaluation was carried out by using simulation analysis and post-implementation data collection to estimate the passing rate, sensitivity, and specificity.

Results
A total of 70,865 historical routine coagulation data were obtained from January 2021 to January 2022 to create VDL. The passing rate was assessed by simulation analysis using 21,277 coagulation results over 3 months(Table 1). In the initial implementation using VDL (5th, 95th percentiles combined with reference value) to the LIS in October 2023, a total of 9,792 cases were collected. The VDL identified 258 cases of aPTT and 115 cases of PT for review, while 9,534 cases of aPTT and 9,677 cases of PT were automatically released. This VDL showed a sensitivity of 99.6% and a specificity of 52.3%. Three error cases were found in partial clot specimens that the analyzer could not detect but were within the reference range.

Conclusions
This study evaluated the use of verification decision limits in an automated post-analytical review for routine coagulation tests which has the potential to improve the efficiency of the result reporting system.
B-202 Clinical and analytical performance evaluation of Savanna RVP4 panel versus three methodologies
Authors: Aldunate J , Vial M , Salgado P , Peña A , Toloza B 
Published: October 2024

Abstract

Background
Rapid molecular diagnosis became a key solution for healthcare institutions across the world, after COVID-19 pandemic. It has enabled diagnosis based on improved quality, accuracy, analytical sensitivity, and turnaround times for laboratory services. It also has positioned this methodology as a trusted technology for point-of-care settings. These solutions also allow to consolidate combinations of different pathogen detection in panels. This study assessed the analytical and clinical performance of the novel Savanna RVP4 panel against other available methodologies.

Methods
A prospective study was performed, considering 84 patient samples obtained from nasopharyngeal swabs. Samples were processed in parallel after collection, using Savanna RVP4, and either QIAstat-Dx Respiratory SARS-CoV Panel (59 samples), Sansure iPonatic (10 samples) and BioFire® Respiratory 2.1 (RP2.1) Panel (15 samples). Samples were collected in either MTU, commercial or homemade PBS.

Results
Overall clinical sensitivity and specificity were 96.43% and 99.64%, respectively for the aggregated panels (Table 1). By technology, the overall clinical sensitivity and specificity were 93.75% and 99.51% versus QIAstat, 100% and 100% versus Biofire, respectively. For iPonatic comparisons, no positive samples were processed and 100% of specificity was obtained. Cycle threshold (Ct) values for positive samples were compared using box plots. Ct values also showed slighlty differences, where means were lower for RSV and Flu A in Savanna (22 and 22.9 respectively) versus other PCR assays (22.5 and 24.5 respectively). For SARS-CoV-2, Ct values were higher versus other methods (19.8 vs 13.6).

Conclusions
Results obtained with Savanna RVP4 were comparable to those obtained with other methodologies, correlating with patient clinical symptoms. Samples showing disagreement for QIAstat comparison panel, in Flu A and RSV assays, corresponded to the same patient samples for the two methodologies, where Ct obtained in QIAstat were above 33. This evaluation also provides strong evidence supporting PBS usage for samples processed in Savanna RVP.
B-229 Extraction-free Nucleic Acid Sample Preparation from Inhibitor Rich Samples via Hyperbaric Heating
Authors: Hambalek J , Wright D , Babikian S , Petrullo M , Allen K , Heeren T , Peytavi R 
Published: October 2024

Abstract

Background
Extraction-based nucleic acid sample preparation for PCR is limited by long processing times, liquid transfers, cost, and storage requirements. Extraction-free approaches enable streamlined sample prep but are severely impacted by inhibitors present in biological sample matrices. We previously reported the use of Hyperbaric Heating (HBH) for effective organism lysis and demonstrate here its effectiveness to prepare nucleic acids for PCR from various inhibitor-rich sample matrix types.

Methods
HBH exposes the sample to high temperature/high pressure environment for a short duration. This process effectively lyses organisms and denatures inhibitors within seconds. Samples are sealed within a pressure-tight metallic vessel, then rapidly heated using magnetic induction. Within the sealed metallic vessel, vaporization of the aqueous sample raises the internal pressure, enabling an internal temperature higher than 100°C. Proprietary sample processing beads containing chelating agents and other proteins protect nucleic acids from fragmentation during heating.

Results
The efficacy of HBH for PCR amplification was tested against commercial kits and extraction-free methods. HBH treatment of nasal swab samples spiked with inactivated SARS-CoV-2 elicited detection down to 125 viral copies/mL. Viruses such as RSV and Influenza spiked in nasal swab samples demonstrated comparable PCR results as extraction prepped samples. HBH treatment of microbe samples, including Candida albicans spiked in urine and Bacillus subtilis spiked in serum, had comparable PCR threshold cycles as microbe specific DNA extraction methods (Table 1).

Conclusions
HBH is a generalizable extraction-free nucleic acid sample prep technology affording detection capabilities comparable to commercial sample prep methods. We demonstrated the use of HBH sample prep for detection of several infectious microorganisms in common biological matrices (nasal swab, serum, urine) without additional sample purification. With its ease of use, speed, and lower cost, HBH will be a key tool in applications where nucleic acid amplification is pivotal for diagnostic and research use.
B-230 Rt-pcr detection and monitoring of infection in periodontal disease: a model of herpesviral-bacterial synergism
Authors: Vigerust D J 
Published: October 2024

Abstract

Background
Periodontal disease results in the breakdown of tissue and ultimately bone and tooth loss. The prevalence of periodontal disease in most countries exceeds 50% and is a direct contributor to a variety of systemic chronic diseases. In addition to bacterial pathogens there is evidence of fungal and viral pathogens having a role in the genesis of inflammation and release of cytokines that stimulate bone and tooth loss. Herpes viruses such as Epstein-Barr virus (EBV), Cytomegalovirus (CMV) and Herpes Simplex 1and 2 (HSV-1 and 2), are seen in less than 5% of normal periodontal tissues but in excess of 50% in severe periodontitis. Epithelial infection with Herpesviruses can lead to impaired and inappropriate immune responses that drive immune evasion and tissue destruction. Viral infection can also alter the expression of proteins in the infected tissues that result in enhanced adherence of bacterial species like Porphyromonas gingivalis and promote active systemic disease. This viral-bacterial synergism is a mechanism of severe disease and should be proactively monitored in dental and medical patients to reduce the burden of morbidity and mortality.

Methods
Several of the eight Herpesviruses have been shown to contribute to cardiovascular disease (CVD), Alzheimer’s, GI cancers and liver disease. Our laboratory has developed and implemented as an LDT, an RT-PCR assay that detects the presence of the Keystone bacterial pathogens (Porphyrmonas gingivalis [Pg], Fusobacterium nucleatum [Fn],Treponema denticola [Td], Tannerella forsythia [Tf] and Aggregatibacter actinomycetemcomitans [Aa]), Candida spp., Streptococcus spp. related to caries formation and four Herpesviruses (EBV, CMV, HSV 1 and 2).

Results
The major pathogenic determinants of severe periodontitis are active herpesviruses, presence of keystone bacterial species, and chronic production of proinflammatory cytokines (TNF-α, IL-1, IL-6). Data from more than 500 patients demonstrates the frequent presence of EBV and CMV in patients also infected with Pg, Td and Fn suggesting a synergism that promotes aggressive periodontitis.

Conclusions
The literature and our data argue for a proactive periodontal testing program that includes viral and bacterial targets to best address and mitigate periodontal disease and the reduce risks for chronic systemic diseases such as CVD, metabolic disease and neurodegenerative disease.
B-237 Engineered Reverse Transcriptases and Taq DNA Polymerases deliver robust yield in the presence of clinically relevant inhibitors
Authors: van der Walt E , Venter P , Faurholm B , Walker J , Nevado W , Wadsworth R , Marshall C , Maasdorp H , Pavlica J , de Beer A 
Published: October 2024

Abstract

Background
The past five years has seen explosive growth in molecular diagnostic assays that rely on sensitive and accurate detection of nucleic acids across a wide range of sample types. As the assays are required to become increasingly sensitive, the need for highly functional and purpose-built enzymatic tools has grown. Reverse transcriptase (RT) and Taq DNA Polymerase (Taq DNAP) are commonly used to detect RNA and/or DNA viruses in patient samples for point of care (POC) diagnostics. However, crude patient samples introduce inhibitors that decrease enzyme activity and increase false negative results in POC testing. In addition, there is a need for faster turn-around time for patient diagnosis which can be enabled by engineering more active and sensitive Taq variants. Herein, we present on our engineered RT and Taq DNAP enzymes that were developed to confer greater activity, thermostability, inhibitor tolerance and/or sensitivity.

Methods
We take a 3-pronged approach to protein engineering: rational design, computational design and directed evolution. Using these techniques, we identified and characterized many RT and Taq DNAP variants. We deeply characterized each RT variant by measuring processivity, inhibitor tolerance and thermostability. First strand synthesis was done at temperatures from 42-65°C in the presence and absence of various clinically relevant inhibitors followed by qPCR to assess cDNA yield. Next, we characterized the inhibitor tolerance of the Taq variants by performing qPCR reactions in the presence of inhibitors. To determine if the Taq variant would be an appropriate fit for fast PCR, the polymerization activity of the Taq DNAP variants were characterized using a primer extension assay.

Results
Reverse transcriptases termed; StellarScript, StellarScript HT and StellarScript HT+ exhibit high processivity at 42°C. StellarScript HT+ exhibited the highest inhibitor tolerance, processivity and thermostability at temperatures up to 65°C thus making StellarScript HT+ well suited to produce high yields with clinical samples. Taq Pol variants were identified that efficiently amplify DNA in the presence of inhibitors.

Conclusions
Based on the increased polymerase activity and inhibitor tolerance, WMG Taq variants are well suited to give robust DNA yields with clinical samples. We were successful in engineering RT and Taq DNAP variants that are highly thermostable, active and inhibitor tolerant and thus will enable breakthroughs in existing POC diagnostics.
B-250 Analytical and Diagnostic Performance Evaluation of Plasma pTau217 in a Clinical Diagnostic Laboratory
Authors: Frykman H , Mammel A , Biehl D , Encarnacion M , Hallett K , Hsiung G , Mousavi A 
Published: October 2024

Abstract

Background
Blood-based biomarkers are a readily accessible and cost-effective screening tool for Alzheimer’s disease (AD). Phosphorylated tau 217 (pTau217) is a specific biomarker for diagnosis and differentiating of AD. It is also a reliable biomarker for facilitating more timely access to disease-modifying therapies. Here, we report the analytical and clinical performance of plasma pTau 217 using high-sensitivity methodologies in a clinical diagnostic laboratory.

Methods
The analytical performance, including precision, specificity, detection limits, and linearity, as well as analyte stability, was assessed. Plasma pTau217 levels were measured using ALZpath pTau217 assay on the Quanterix HD-X Simoa® platform or LUMIPULSE plasma pTau217 on the Lumipulse G1200 platform. Clinical Validation conducted at Neurocode USA & BC Neuroimmunology involving 263 samples with amyloid PET data, 219 healthy aging samples and 150 Pathology confirmed samples.

Results
The mean plasma pTau 217 concentrations in healthy aging samples were 0.22 ± 0.08 ng/L. ALZpath pTau217 assay has an analytical measurement range of 0.06 - 10 pg/mL, with a limit of blank (LoB) of 0.0035 ng/L, a limit of detection (LoD) of 0.0074 ng/L, and a limit of quantification (LoQ) of 0.0600 ng/L. Its linearity extends from 0.19 to 2.8 ng/L, with repeatability demonstrating intra-laboratory precision above LoQ ≤ 20% CV. Stability is maintained at 4⁰C for ≤ 1 week, at room temperature for ≤ 24 hrs, at -20⁰C for ≤ 4 weeks, and at -80⁰C for ≤ 4 weeks, with freeze/thaw cycles tolerated up to 5 times. Furthermore, no interference was detected at the maximum concentrations tested for bilirubin, hemoglobin, biotin, and heterophilic antibodies. ROC analysis yielded an AUC of 0.92 to 0.93, identifying a suitable clinical cutoff of &lt; 0.4 ng/L.

Conclusions
The outstanding clinical and analytical performance of pTau217 supports its adoption as a robust screening tool in clinical practice, facilitating accurate and reliable diagnosis of AD by clinicians.
B-279 Evaluation of the Analytical Performance of Two Therapeutic Drug Monitoring Assays on the Atellica CI Analyzer
Authors: Huff J , Valdivia B , Wilkins G , Arrode-Bruses G , Leipold H , Snyder J 
Published: October 2024

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 &lt;5.4% and &lt;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.
B-283 Biological Consequences of Nitrous Oxide Abuse: Insights from Targeted Metabolomics Investigation
Authors: Grzych G , Gernez E , Plasse L , Deheul S , Niguet J , Bennis A , Tard C , Douillard C , Scliffet D , Bossaert C , Girot M , Dobbelaere D , Diesnis R 
Published: October 2024

Abstract

Background
The recreational use of nitrous oxide (N2O), commonly known as laughing gas, has experienced a notable surge in popularity in recent times. According to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), N2O is recognized as one of the most widely used psychoactive substances in Europe as of 2022. Its use also extends to Asia and America, according to literature. However, prolonged consumption of N2O has been associated with neurological complications linked to the functional inactivation of vitamin B12, disrupting One Carbon Metabolism. This study aims to explore the metabolic effects of N2O intoxication through a targeted metabolomics approach.

Methods
We conducted a prospective collection of clinical and biological information from 37 N2O users and 37 non-users (control group). Utilizing a targeted metabolomics method, we analyzed plasma amino acids using liquid chromatography coupled with mass spectrometry. Our statistical analysis encompassed principal component analyses, random forests, Mann-Whitney tests, Student's t-tests, and Spearman rank tests.

Results
Metabolomic analyses have demonstrated effective differentiation between patient groups. In comparison to controls, N2O consumers displayed reduced plasma levels of taurine, cystine, and methionine, alongside elevated plasma levels of serine and sarcosine. These findings suggest a potential influence of N2O on the cystine-methionine metabolic pathway. The decrease in methionine levels may be attributed to the decreased activity of methionine synthase (MS) due to vitamin B12 inactivation, which could partially explain the observed increase in serine levels. The rise in sarcosine levels could be explained by an increase in betaine-homocysteine S-methyltransferase (BHMT) activity. Moreover, dysfunction in cystathionine-β-synthase (CBS) or cystathionine γ-lyase (γ-CYS) may lead to the accumulation of upstream metabolites (such as serine) and a reduction in downstream metabolites (such as cysteine and taurine).

Conclusions
This study sheds light on potential new impacts of N2O, particularly on the plasma levels of serine, cystine, and taurine, indicating a potential modulation of enzymes involved in the conversion of homocysteine to taurine (CBS and/or γ-CYS). Additional investigations are required in a larger group of patients, which corresponds to the aims of the EFLM Task & Finish Group: Biomarkers of Diagnosis and Follow-up of Nitrous Oxide Abuse: https://www.eflm.eu/site/who-we-are/committee/science-committee/fu/tfg-biomarkers-of-diagnosis