bluuebunny/crossref_metadata_2025_split huggingface dataset:
A-296 Validation of a Real Time PCR Kit for the Detection and Differentiation of MRSA, MSSA and MRCoNS in Respiratory Clinical Samples
Authors: Franco-Marín E , Dehesa-García B , Escolar C , García-Manrique B , Cebollada R , Monforte-Cirac M , Millán-Lou M , Alonso H , Aspiroz-Sancho C 
Published: September 2023

Abstract

Background
Staphylococcus aureus infections are remarkable due to their high morbimortality. In addition, antibiotic resistance of these bacteria is a cause of concern since it worsens the patient prognosis and it is associated to higher morbidity, mortality and cost of treatment. The aim of this study was to assess the clinical performance of the assay VIASURE Methicillin resistant Staphylococcus aureus Real Time Detection Kit in clinical and epidemiological respiratory samples.

Methods
Respiratory samples were collected from patients admitted to intesive care or ward of the Hospital Royo Villanova (Zaragoza, Spain). A total of 653 respiratory samples (both clinical and epidemiological) were employed: 189 nasal swab, 103 pharyngeal, 161 bronchoalveolar aspirate (BAS), 154 bronchoalveolar lavage (BAL) and 46 sputa samples previously characterised using culture methods. Results were compared with other commercial validated molecular assay (RIDA®GENE MRSA (R-biopharm)) presenting the same molecular targets as the assay under study. The characterisation performed by VIASURE is based on the combined results of the three targets S. aureus SA 442/coA, mecA/mecC and Sccmec-orfX junction and may report the following genotypes: methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible Staphylococcus aureus (MSSA)), methicillin-resistant coagulase negative Staphylococcus (MRCoNS) and methicillin-susceptible Staphylococcus aureus and methicillin-resistant coagulase-negative Staphylococcus (MSSA and MRCoNS).

Results
VIASURE assay correctly reported MRSA/MSSA/MRCoNS genotyping results with sensitivity and specificity values over 90% in all sample matrixes (Table 1).

Conclusion
The diagnostic performance of the assay under study demonstrated to be suitable tool for the molecular diagnosis of coagulase negative Staphylococci, S. aureus and their methicillin resistance causing mutation when compared with reference methods.
A-300 Evaluation of Different Storage Conditions of Nasopharyngeal Swabs for the Detection of Influenza A, Influenza B and RSV
Authors: Martínez-Santolaria M , Sota-Diez C , García-Manrique B , Machetti-Mareca E 
Published: September 2023

Abstract

Background
Every year, Influenza A (FluA), Influenza B (FluB) and Respiratory Syncytial Virus (RSV) affect our communities and increase the number of patients in our health systems. Molecular techniques, such as real-time PCR have become essential, not only for the diagnostic but also for the epidemiological studies. High amounts of samples or retrospective analysis need the use of samples stored at different conditions. For this reason, a stability study of nasopharyngeal swabs (NP) in Viral Transport Medium (VTM) for FluA, FluB and RSV was performed.

Methods
Twenty-eight negative FluA, FluB and RSV NP samples in VTM (Vircell, Spain) were used in this study. All samples were mixed into one pool and divided into 7 aliquots. One of them served as a negative control. The others were enriched (each) with different concentrations of viral cultures from ATCC (VR-95PQ™, VR1804PQ™, VR26PQ™) to obtain two positive samples for each pathogen. Samples were stored under specific conditions of time and temperature before being processed: 1 and 2 days stored at 25°C, 3 and 6 days stored at 4°C, and 8, 30 and 180 days stored at −20°C. Each condition was extracted in triplicate with the MagDEA Dx SV kit, using the magLEAD® 12gC instrument (Precision System Science Co.) and analysed with VIASURE SARS-CoV-2, Flu & RSV Real Time PCR Detection Kit (Certest Biotec S.L) in triplicate on CFX96™ Real-Time PCR Detection System (Bio-Rad). The results were compared with the data obtained on the first day (0 h).

Results
All positive samples were detected in all conditions and matrices. No amplifications were observed in negative samples. There were no major differences compared with the data obtained on the first day. However, a Cq delay of around 1 unit was observed in all pathogens when samples were stored 2 days at 25°C. For this reason, this storage condition would not be recommended.

Conclusion
NP samples in VTM for the detection of FluA, FluB and RSV can be stored at 25°C for up to 1 day, 4°C for up to 6 days, or frozen at −20°C for up to 180 days.
A-372 Increased Sensitivity in Detection of SARS-CoV-2 Antigen Using RADI COVID-19 Ag Rapid Test
Authors: Kee S , Choi J , Jeon J , Heo M , Park J , Choi H 
Published: September 2023

Abstract

Background
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapid point-of-care antigen tests can provide easy and fast results for the diagnosis of coronavirus disease 2019 (COVID-19). However, due to the lower sensitivity of rapid antigen tests relative to reverse transcription polymerase chain reaction (RT-PCR), they might miss many infectious COVID-19 cases. We evaluated and compared a new rapid antigen test with the current approved one.

Methods
The RADI COVID-19 Ag Rapid Test (KH Medical, Hanam, Korea) was validated with a total of 1054 pre-confirmed residual nasopharyngeal swab samples (258 positives and 796 negatives) by PowerChek 2019-nCoV Real-time PCR (Kogene Biotech, Seoul, Korea). Among them, 258 positives and 546 negatives were used to compare the RADI COVID-19 Ag Rapid Test with the STANDARD Q COVID-19 Ag Test (SD Biosensor, Suwon, Korea).

Results
Using RT-PCR results as the reference, the overall sensitivity and specificity of RADI COVID-19 Ag Rapid Test were 82.2% (212/258; 95% confidence interval, CI [76.9–86.6]) and 99.1% (789/796; 95% CI [98.2–99.7]), respectively. The positive predictive value and negative predictive value were 96.8% (212/219; 95% CI [93.5–98.5]) and 94.5% (789/835; 95% CI [93.0–95.7]), respectively. The accuracy was 95.0% (1001/1054; 95% CI [93.5–96.2]) with Cohen's kappa value of 0.86 (95% CI [0.82–0.89]). The positive percent agreement and negative percent agreement of the RADI COVID-19 Ag Rapid Test for STANDARD Q COVID-19 Ag Test were 97.0% (159/164; 95% CI [93.0–99.0]) and 90.6% (580/640; 95% CI [88.1–92.8]), respectively, and those of STANDARD™ Q COVID-19 Ag Test for RADI COVID-19 Ag Rapid Test were 72.6% (159/219; 95% CI [66.2–78.4] and 99.2% (580/585; 95% CI [98.0–99.7], respectively. The overall percent agreement between the two rapid antigen assays was 91.9% (739/804; 95% CI [89.8–93.7]) with Cohen's kappa value of 0.78 (95% CI [0.73–0.83]). Among the 65 discrepant samples between the two rapid antigen assays, 56 were positive as per RT-PCR, which showed 53 samples negative for STANDARD Q COVID-19 Ag Test and 3 samples negative for RADI COVID-19 Ag Rapid Test. The median E gene Ct value of the 65 discrepant samples was 28.2 (interquartile range: 26.1–32.3).

Conclusion
RADI COVID-19 Ag Rapid Test provides acceptable sensitivity and specificity according to the validation criteria for KFDA immunological test product approval. Furthermore, RADI COVID-19 Ag Rapid Test shows improved sensitivity compared to the current approved rapid antigen test.
B-012 Validation of a Urine Ammonium Assay on Roche Cobas c502 Chemistry Analyzer
Authors: Song L , Tong K H , Fournier M I 
Published: September 2023

Abstract

Background
Urine ammonium (uNH4+) excretion is critical for the maintenance of acid-base balance and reduced uNH4+ excretion can cause retention of hydrogen ions resulting in metabolic acidosis in patients with chronic kidney disease (CKD). In addition, study found that declined urine ammonium excretion is an independent factor for predicting the worsening of kidney function. However, urine ammonium assay is not readily available on automated chemistry analyzers. We developed a protocol for the determination of urine ammonium levels using an ammonia assay for plasma samples on an automated chemistry analyzer. In this report, we present the urine ammonium protocol used in our laboratory and the validation of the urine ammonium assay.

Methods
All urine samples were diluted 100 times with deionized water and ammonium in the diluted samples was measured using the NH2L2 ammonia II assay on Roche cobas c502 chemistry analyzer. When a urine sample containing ammonium level less than 1.06 mmol/L, a 50-fold dilution was performed. Recovery was determined in six urine samples when 9 parts of the urine were mixed with one part of a standard 200 mmol/L ammonium solution (made with Ammonium Chloride from Thermo Scientific). Linearity was determined by serial dilutions of a sample containing 187 mmol/L ammonium. Limit of quantitation was determined using a 50-fold dilution protocol. The reference interval of 3–65 mmol/L was verified using 64 urine samples from volunteer donors and patient without CKD and metabolic acidosis. The stability was determined by testing two samples kept at room temperature for 0, 8, and 24 hour, respectively. The within-run precisions were determined by testing three urine samples 20 times in a run, and the between-run precisions were determined by testing three samples 2 times a day for 10 days, respectively.

Results
Recovery was 95.8% to 102.2% in six urine samples contained varying amount of ammonium ranged between 6.0 mmol/L to 22.2 mmol/L. Linearity was 0.5–99 mmol/L. Limit of quantification was 0.5 mmol/L. The reference interval of 3–65 mmol/L was verified. Urine ammonium was stable up to 24 h at room temperature. For within-run precision, the coefficient of variation (CV) was 1.51%, 0.49%, and 0.54% for samples containing 6.0 mmol/L, 27.7 mmol/L, and 75.7 mmol/L ammonium, respectively. For between-run precision, the CV was 2.54%, 5.98%, and 6.13% for samples containing 4.4 mmol/L, 27.9 mmol/L, and 55.1 mmol/L ammonium, respectively.

Conclusion
Urine ammonium levels can be determined using the NH2L2 ammonia II assay on Roche cobas c502 chemistry analyzer after manual dilution of urine samples 100 times with deionized water. The limit of quantitation is extended to 0.5 mmol/L when urine samples are diluted 50 times with deionized water.
B-045 A Descriptive Study of the Clinical Impacts on COVID-19 Survivors Using Telemonitoring (The TeleCOVID Study)
Authors: Chow J S 
Published: September 2023

Abstract

Background
There is increasing evidence that COVID-19 survivors are at increased risk of experiencing a wide range of cardiovascular complications post infection; however, there are no validated models or clear guidelines for remotely monitoring the cardiac health of COVID-19 survivors. This study aims to test a virtual, in-home healthcare monitoring model of care for detection of clinical symptoms and impacts on COVID-19 survivors. It also aims to demonstrate system usability and feasibility.

Methods
This open label, prospective, descriptive study was conducted in South Western Sydney. Included in the study were patients admitted to the hospital with the diagnosis of COVID-19 between June 2021 and November 2021. Eligible participants after consent were provided with a pulse oximeter to measure oxygen saturation and a S-Patch EX to monitor their electrocardiogram (ECG) for a duration of 3 months. Data was transmitted in real-time to a mobile phone via Bluetooth technology and results were sent to the study team via a cloud-based platform. All the data was reviewed in a timely manner by the investigator team, for post COVID-19 related symptoms, such as reduction in oxygen saturation and arrhythmia. This study was designed for feasibility in real clinical setting implementation, enabling the study team to develop and utilise a virtual, in-home healthcare monitoring model of care to detect post COVID-19 clinical symptoms and impacts on COVID-19 survivors.

Results
During the study period, 23 patients provided consent for participation. Out of which 19 patients commenced monitoring. Sixteen patients with 81 (73.6%) valid tests were included in the analysis and amongst them seven patients were detected by artificial intelligence to have cardiac arrhythmias but not clinically symptomatic. The patients with arrhythmias had a higher occurrence of supraventricular ectopy, and most of them took at least 2 tests before detection. Notably, patients with arrhythmia had significantly more tests than those without (t-test, t (13) = 2.29, P &lt; 0.05).

Conclusions
Preliminary observations have identified cardiac arrhythmias on prolonged cardiac monitoring in 7 out of the first 16 participants who completed their 3 months follow-up. This has allowed early escalation to their treating doctors for further investigations and early interventions.
B-064 Analytical and Diagnostic Performances of Anti-Integrin Antibody System in Inflammatory Bowel Disease
Authors: Schwalbe M , McLachlan O , Everts-van der Wind A , Dervieux T 
Published: September 2023

Abstract

Background
Anti-integrin αvβ6 autoantibodies may have value in the diagnosis of Inflammatory Bowel Disease (IBD) and more specifically Ulcerative Colitis (UC). Our objective was to establish the analytical and diagnostic performance of this novel autoantibody system in distinguishing IBD from a group of Normal Healthy Volunteers (NHV) and UC from Crohn’s Disease (CD).

Methods
All testing was performed using a Tecan Evo200 equipped with 8-channel and 96-channel arms, plate washer, and plate reader. The ELISA assay used calibration controls and diluted serum samples added to ELISA plates coated with Integrin αvβ6 antigen. Anti-human IgG horseradish peroxidase complexed with Anti-integrin αvβ6 antibodies was detected using colorimetry. The analytical performance was evaluated by using repeatability and reproducibility with coefficient of variation (CV) calculated. The diagnostic performances were evaluated by testing specimens collected from consented subjects available from a biobank in autoimmune gastrointestinal diseases. This consisted of 60 NHV, and 187 IBD (91 CD and 96 UC). Sensitivity, specificity, diagnostic odds ratio (OR), positive and negative predictive values (PPV and NPV) were estimated.

Results
Intra-assay CVs ranged from 1.5% to 5.2% over dynamic range. Inter-assay CVs were below 10%. Median titers were below 5 U/mL for NHV and CD, and 26 U/mL for UC (Fig. 1). Cutoff of 5 U/mL was 100% specific for UC and CD. Sensitivity for UC and CD was 80% (77/96), and 15% (14/91), respectively. Diagnostic Odds Ratio yielded 22.3-fold (95% CI: 10.5–47.5) higher likelihood of UC than CD in the presence of Anti-integrin αvβ6 titers above cutoff, with PPV and NPV values of 84% (76%-90%) and 81% (74%–87%), respectively (50% pre-test).

Conclusion
We have established the analytical performance of an Anti-integrin αvβ6 autoantibody ELISA assay. These preliminary data suggests that the Anti-Integrin αvβ6 autoantibody system is highly specific for UC with high sensitivity and specificity.
B-124 Applicability of measurement uncertainty in the validity of results in the clinical laboratory
Authors: Martinez Nieto O , Garzón A , Barrera V , Romero A , Garzón A , Hernández N 
Published: September 2023

Abstract

Background
The results of the clinical laboratory must comply with attributes of precision, veracity, and accuracy to guarantee the validity of the result; since the assurance of analytical quality, different performance evaluation strategies have been applied with the use of tools such as total permissible error (ETa) and sigma metric. However, based on the requirements to qualify for the accreditation process by standards such as ISO 15189 and ISO 17025, the concept of the “measurement uncertainty” of the measured magnitude values was introduced, giving special relevance in the interpretation of the values obtained, therefore it is important to consider its estimation and evaluation as a tool that contributes to patient safety in the interpretation of clinical decision limits.

Methods
Uncertainty estimation was performed for forty-one measurands that were previously selected considering the variables of clinical risk and processing volume. The estimation of uncertainty, ETa and sigma metric were made with the RANDOX Acusera software 24/7 online from the information obtained from the internal quality control data and the scheme of the external quality evaluation. The uncertainty obtained was compared against four criteria of acceptability of uncertainty.

Results
After comparing the uncertainty obtained against the four criteria of acceptability of uncertainty, it was found that the most demanding criterion is that derived from the reference biological interval. The implementation of this criterion would allow objective comparability of performance between laboratories. Conclusions: The estimation of uncertainty as an indicator of the validity of the results provides relevant information in the interpretation of the results that are within the limits of clinical decision, while the ET and sigma metric contribute to the monitoring and control of the performance of the analysis or measurement procedure.

Conclusion
We observed that the efforts of the laboratory for minimizing the variation sources that can affect the analytical accuracy have been prolific. Total Error quantification, Sigma 6 and MU have a correlation, favorably impacting the tests performance. Aiming to guarantee a constant improvement of the results’ quality, the Total Error and MU goals must be periodically revised, ensuring their utility throughout time.
B-135 Research Trends and Hotspots of Glial Fibrillary Acidic Protein in Body Fluid for Alzheimer’s Disease: A Bibliometric Analysis
Authors: Zou Y , Qiu L 
Published: September 2023

Abstract

Background
As the most common form of dementia, Alzheimer’s disease (AD) is prevalent worldwide. An increasing number of studies have focused on glial fibrillary acidic protein (GFAP), an astrocytic cytoskeletal protein, for the development, diagnosis and prognosis of AD. Therefore, this study aimed to analyze trends and hotspots of GFAP in body fluid for AD by using a bibliometric method, which is missing in current publications.

Methods
We systematically searched the Web of Science Core Collection for published papers on GFAP in body fluid and AD. All articles and reviews from inception to December 31, 2022, were included in this study. Full records and cited references of all publications were derived, imported into Microsoft Excel, and analyzed by BIBLIOMETRC Online analysis platform and VOSviewer software.

Results
A total of 2269 publications including 2166 articles were ultimately included based on the inclusion criteria. The data showed that the number of published papers on GFAP in body fluid and AD is annually increasing, which was published in 81 countries/regions and 527 academic journals. Separately, the top 3 prolific countries/regions and institutions were USA, China and England, Univ Gothenburg (Sweden), Univ Fed Rio Grande do Sul (Brasilia) and UCL Queen Square Institute of Neurology (England). Journal of Alzheimer’s Disease, Brain Research, and Neuroscience contributed the most publications; Zetterberg, Henrik from Univ Gothenburg, Blennow, Kaj from Univ Gothenburg and Verkhratsky, Alexei from the University of Manchester were the top 3 prolific and cited authors. The most published and linked meaningful keywords included oxidative stress, inflammation, microglia, hippocampus and amyloid, which also annually increased in recent publications.

Conclusion
Based on a bibliometric analysis, the number of publications on GFAP in body fluid and AD are rapidly increasing, especially in the past several years. Oxidative stress and inflammation are research hotspots, and the diagnostic performance of GFAP in body fluid need to be further summarized and verified.
B-210 Spectrum of Germline Mutation with Characteristic MLH1 Hotspots and High Concordance with MMR Deficiency Phenotype in Lynch Syndrome Patients in Taiwan
Authors: Chang P Y , Chang S C , Wang M C , Chen C C , Chiang J M 
Published: September 2023

Abstract

Background
Patients carried defects on cancer susceptibility genes or had cancer family history have at least twice the risk of developing cancer than the general population, with both early onset and multiple cancers features. For elucidating the carrier rate of cancer susceptibility genes in patients with inherited colorectal cancer (CRC) and endometrial cancer (EnCa) in Taiwan, we established a NCCN guided 30-gene panel which included four DNA Mismatch Repair (MMR) genes to detect the germline mutation of patients with Lynch Syndrome. Correlation of genotype and phenotype of MMR enzymes are under investigation as well.

Methods
Sixty-eight blood samples were collected from unrelated cancer patients, 42 of them were from patients with inherited colon cancer, 13 from patients with diagnosis of both CRC and endometrial cancer and 13 from patients with early onset EnCa. 30-gene panel was performed by next generation sequencing (NGS) platform and variants were annotated following ACMG guideline. MMR protein expression in tumor tissue sections were identified by conventional immunohistochemistry (IHC) stain. Loss of nuclear staining were classified as MMR deficiency.

Results
Average age of first tumor onset of 68 patients were 49.2 years old. 54% (37/68) of the subjects had at least one germline mutations with pathogenic effect or deleterious variant predicted by in silico protein function software. Five of them carried two heterozygous mutations. Total 42 mutations appeared majority on three MMR genes, MLH1 (17/42, 40%), MSH2 (10/42, 24%) and MSH6 (6/42, 11%) with notified three hotspots on MLH1 p.R265C (7/17, 41%); p.T117M (2/17, 12%) and p.K618del(2/17, 12%). The rest mutations spread sporadically on nine genes (PMS2, TP53, CHEK2, POLE, POLD1, ATM, EPCAM, MLH3 and RNF43). For exploring the effect of germline mutation on MMR protein expression status on tissue, we compared the MMR IHC results and the germline mutation pattern. As high as 57% concordance between phenotype and genotype were found. We also collected six blood samples from relatives of our CRC cohort to demonstrate the inheritance and pathogenesis of the germline mutation. Exactly the same germline mutations can be found in diseased relatives among different generation or siblings.

Conclusion
In spite of having founder mutations on MLH1 gene in Taiwanese Lynch syndrome, most of the germline mutations randomly occurred in MMR-related genes. Comprehensive cancer susceptible gene screening panel by NGS is a cost-effective way to identify the inherited status of individuals with family cancer history and serves as a surrogate tool to predict MMR protein expression. Genetic counseling and prophylactic therapeutic information can be provided for positive cases for better cancer prevention.