bluuebunny/crossref_metadata_2025 huggingface dataset:
A-243 Quantitative Bacteriology Parameters for Seal-Packaged Agar Plates Challenged with Experimental Low-resource Tropical Field Clinic Stress
Authors: Font B K , Vaughn P
Published: October 2024

Background

InTray® Mueller Hinton Chocolate (MHC) and Colorex™ Screen (CS) plates are in vitro diagnostic devices combining prepared bacteriological agar-media with Biomed’s ‘InTray®’ format (a double sealed-packaging cassette system that provides extended shelf-life 12 months past the date of manufacture). The devices are intended for use with clinical specimens to culture, isolate and identify potentially pathogenic bacteria. This study evaluated MHC and CS device performance at 7 and 13 months past the date of manufacture after product was experimentally challenged with stress replicating a low-resource tropical field clinic scenario.

Methods

MHC and CS plates were exposed to high temperature (40.5°C ± 0.5) and high humidity (74.5 ± 2.5% relative humidity) for an extended time-period (18 days). After the 18 days of heat treatment, the stress-group plates were stored in the lab at working room temperature (20-25°C) for the remainder of the study. Quantitative differences between control-groups (stored under refrigeration: 2-8°C) and heat-stress treatment groups for both MHC and CS were examined via CFU/mL measurements comparing three different lab-strain bacteria chosen based on clinical sub-culturing prevalence from blood bottles; Escherichia coli (ATCC 25922), Streptococcus pneumoniae (ATCC 6305), and Staphylococcus aureus (ATCC 25923). Briefly, 24-hour (18-30 h) old bacterial colony suspensions (grown on MHC) were prepared in 0.85% saline solution, adjusted to a 0.5 McFarland standard (here defined as 0.08-0.96 Absorbance @ 625 nm), measured in triplicate and diluted. A 20 μL volume from the lowest dilution (2.5 x 103 CFU/mL) was then spread-plated to each plate in order to count colony-forming units (CFU) in the acceptable range of 25-250.

Results

Quantitative CFU/mL differences between control-groups (stored under refrigeration: 2-8°C) and heat-stress-treatment groups (>40°C and high humidity) for MHC and CS for three different test bacteria (listed above) were not statistically significant when tested at 13 months. The CS stress and control group comparison for S. pneumoniae with a p value < 0.05 at 7 months had a p value > 0.05 at 13 months, suggesting that the difference between the CFU counts may not be significant in biological terms.

Conclusions

In conclusion, control and heat-stress treatment groups for both MHC and CS met acceptable performance criteria as expected for the products, 13 months after the date of manufacture.
A-250 Evaluation of Liver Fibrosis in Schistosomiasis Mansoni Using the ELF (Enhanced Liver Fibrosis) Score
Authors: Ozaki B C , Thorp R D , Batista A D , d. Mariz C , Diniz G T , Barreto A V , de Morais C N , Domingues A C , Lopes E P
Published: October 2024

Background

Measuring the presence and pattern of periportal fibrosis (PPF) in schistosomiasis mansoni (SM) is essential for diagnosing its clinical forms and detection of portal hypertension. For these evaluations, the gold-standard has been ultrasound scan (US) using Niamey classification, however it requires sophisticated equipment and well-trained operator. ELF (Enhanced Liver Fibrosis) is an index capable of quantifying liver fibrosis in chronic liver diseases, although there have been few studies evaluating PPF in SM.

Aim

To assess serum ELF levels according to the PPF patterns established by ultrasound using the Niamey classification in patients with schistosomiasis.

Methods

A cross-sectional, bidirectional analytical study was carried out with patients from an endemic area (patterns A, B, C and D) and from an SM reference outpatient clinic (patterns D, E and F). Clinical data and 10 mL of blood were collected, centrifuged and frozen to measure and calculate the score by the ELF™ Test (Atellica® IM), according to the equation: [ELF = 2.278 + 0.851 ln(HA) + 0.751 ln(PIIINP) + 0.394 ln(TIMP-1)] and expressed as a numerical value without unit. US using GE Healthcare Logic E (endemic area) or Siemens Acuson S2000 (outpatient clinic) equipment were performed by a single examiner.

Results

Of the 196 patients evaluated, 114 (58.2%) were women with a mean age of 45 ± 15.42 years. They had the following PPF patterns: 18 pattern A+B; 64 pattern C; 56 pattern D; 49 pattern E and 9 pattern F. The median ELF values were higher according to PPF progression in these 5 groups (p = 0.0021), respectively: (A+B = 8.36); (C = 8.40); (D = 8.64); (E = 8.99) and (F = 9.75). The ELF was able to differentiate patients without PPF, with mild, moderate and advanced PPF: A+B vs C vs D vs E+F (p = 0.0024), as well as patients with advanced PPF from those without fibrosis or with moderate fibrosis: A+B vs E+F (p = 0.0464) and C+D vs E+F (p = 0.0007). The index was also able to differentiate patients with absent or mild PPF from those with moderate or advanced PPF: A+B+C vs D+E+F (p = 0.0015).

Conclusions

The ELF showed great potential as a tool for assessing PPF in patients with schistosomiasis mansoni, being able to differentiate those with little fibrosis from those with moderate or advanced fibrosis.
A-251 Simplification of Molecular Diagnostics for Sexually Transmitted Infection Point-of-Care Testing
Authors: Seely S O , Roberts J , Collins D , Zingg J , Deo S , Daunert S
Published: October 2024

Background

HPV-caused cancers contribute to a large disease burden, accounting for 5% of all cancers. It is estimated that over 700,000 people develop HPV-related cancers each year with the majority being cervical cancer. The burden of this disease is disproportionately carried by low-income countries with the highest rates of HPV cervical infections primarily found in sub-Saharan Africa, Latin America, Eastern Europe, and South-East Asia. Many regions in low-resource countries lack adequate access to sensitive point-of-care screening tools, preventing timely diagnosis and treatment. Current low-cost methods, such as Pap smears and visual inspection using acetic acid suffer from low sensitivity, specificity, and reproducibility which limit their effectiveness as a screening modality. Many countries use nucleic acid amplification tests (NAATs) to identify key HPV infections which may progress towards cervical cancer. However, the expenditure for NAAT-capable equipment and reagents are cost-prohibitive for rural and underserved communities. To reduce screening barriers, we developed an isothermal HPV molecular test that can detect all 14 cancer-causing HPV strains using a novel amplification methodology combined with G-quadruplex DNAzyme colorimetric detection.

Methods

We developed a novel isothermal amplification technique that is related to loop-mediated isothermal amplification (LAMP) but uses modified looped primers to enable exponential amplification at 60°C for 1 hour. The modified primers only require two binding sites compared to 4-6 in LAMP. To detect the amplified products, we used G-quadruplex peroxidase-like DNAzyme probes which reduce ABTS to produce a visually interpreted result. Analytical validation evaluated the method’s limit of detection, specificity, and accuracy. As proof of concept in a relevant matrix, clinical cervical brushings collected ThinPrep Pap media were tested with the new method and compared to an FDA-approved reference qPCR test.

Results

Repeated experiments demonstrate that the lowest detectable HPV DNA concentration was approximately 1000 genomic copies/µL with no amplification with other pathogens. As proof of concept, the comparison to the reference standard demonstrated high accuracy.

Conclusions

The application of our assay is intended as a near-patient screening tool with further evaluation by a clinician for confirmation. With an accurate and rapid screening tool, we envision low-resource regions across the world will have the tools to rapidly detect and treat cervical cancers in their early stages.
A-271 Expansion of sample viability for self-collected urine specimens containing CT/NG & TV/MG utilizing the Roche cobas® 6800 System
Authors: Muldrow R , Sicari B , Caro Azoy E , Beal S
Published: October 2024

Background

The CDC estimates that 1 in 5 Americans have an STI. Home collection for STIs could help mitigate the stigma, cost, and accessibility, which contribute to low diagnosis rates and disparities in diagnosis and treatment. Home self-collected specimens occasionally arrive in the lab with volumes higher or lower than what is required by the assay manufacturer’s specifications for self-collection. This study demonstrates that sample stability is retained after temperature fluctuation via shipping - even when the correct ratio of buffer to sample has been disturbed, a precise and accurate measurement persists. Our goal is to improve accessibility to discreet, patient collected STI tests.

Methods

Positive samples were prepared by spiking negative urine with organisms near the manufacturer’s limit of detection (LoD). Properly collected samples were aliquoted into tubes with 5mL volumes as per manufacturer specifications. Improperly collected samples were either overfilled (9mL for CT/NG, 7mL for TV/MG) or underfilled (1mL for CT/NG, 2mL for TV/MG). Samples underwent temperature cycling to mimic summer or winter shipping conditions. Ambient temperature studies were conducted on over/underfilled specimens. All samples were baseline tested and compared qualitatively to the manufacturer's claimed LoD using the Roche c6800 and the IVD assays for CT/NG & TV/MG.

Results

Improperly filled samples were stable at ambient temperature for 63 days for CT/NG, and 59 days for TV/MG. See chart for temperature cycling results. All samples (n=164) showed 100% qualitative agreement with their baseline result after summer and winter shipping challenges.

Conclusions

Urine samples that fail to satisfy the manufacturer’s self-collection specifications or have endured temperature fluctuations still yield accurate CT/NG & TV/MG results. These results indicate the potential to enhance sample viability and patient accessibility utilizing validated IVD assays.
A-276 Unraveling Pathogen Dynamics In Pediatric Meningitis Complications During The Omicron Variant Outbreak In Taiwan
Authors: Huang C , Lin Y , Hsieh T , Tsao K , Shih S , Chiu C
Published: October 2024

Background

Taiwan, once celebrated for its remarkable control over COVID-19, faced an unexpected surge in pediatric cases during the first wave of the omicron variant in April 2022. Alarming data revealed acute encephalitis emerging in half of the severe or fatal COVID-19 cases in children within the initial two months of the omicron epidemic. This study delves into the intricate microbiota patterns and viral pathogens contributing to encephalitis complications in affected children.

Methods

The study enrolled 36 pediatric patients, comprising 11 patients with severe encephalitis, 12 patients with mild encephalitis, and 13 normal controls. Nasal swabs were collected for pathogen detection. For respiratory microbiota analysis, 16S rRNA metagenomic sequencing was employed, while the Illumina Respiratory Pathogen ID/AMR Enrichment Panel was used for respiratory pathogen identification.

Results

Microbiota analysis of nasal swabs from COVID-19 pediatric patients with meningitis complications revealed prevalent Corynebacterium, Staphylococcus, Dolosigranulum, Acinetobacter, Moraxella, and Streptococcus. Conversely. No predominant bacterial species were detected in the normal control group. Nasal swab respiratory pathogen detection identified coinfections, particularly Herpesviridae viruses such as human herpesvirus 6, Epstein-Barr virus, and Cytomegalovirus in pediatric patients with meningitis complications. Notably, two severe encephalitis cases exhibited coinfections involving rhinovirus, SARS-CoV-2, and Herpesviridae viruses (HHV-6, EBV). In one fatal case, distribution of Streptococcus genes among total geneomes reaches 40.69%, 7 drug resistant genes were detected.

Conclusions

This study suggests a potential link between latent Herpesviridae virus coinfections (HHV-6, CMV, EBV) and meningitis complications in pediatric patients. Furthermore, the presence of a secondary respiratory virus (rhinovirus) coinfection appears to be associated with severe complications. These findings shed light on the complex pathogen dynamics contributing to the emergence of encephalitis in pediatric COVID-19 cases during the omicron variant outbreak in Taiwan.
A-280 The Good, the Bad, and the Downright Inappropriate reporting of Gram Positive Resistance Genes in a Proficiency Testing Program
Authors: Mills E , Casey D , Kolehmainen L
Published: October 2024

Background

Molecular technologies can rapidly identify the pathogen, allowing for the correct antimicrobial agent to be used for initial treatment. Many laboratories have implemented molecular technologies to identify the causative agents of infections from various bodily sources. Screening for potential resistance genes to common antimicrobial agents provides high value to clinicians to help guide optimal antimicrobial therapy selection. CLIA ‘88 required proficiency testing for physician office laboratories in 1994. This was in addition to the requirement for hospital and reference laboratories instituted under CLIA ‘67. This study compares the accuracy of laboratory performance for molecular multiplex platforms in the detection of Gram positive resistance genes from gold standard qualified samples in a novel proficiency program.

Methods

American Proficiency Institute, an independent proficiency testing provider, reviewed the reporting of various molecular multiplex systems against simulated patient samples in proficiency samples offered in 2023. Participants were instructed to only report resistance genes their systems were capable of testing for, and ensure they were appropriate for the organism recovered. Failure rates for participants were evaluated against an 80% participant consensus standard for detection of resistance genes.

Results

During the 2023 proficiency year, Gram positive targets were included 14 times in 4 different multiplex programs. Accuracy for correct reporting of resistance genes appropriate for the organism recovered ranged between 71.0%- 100%. Conversely, the number of laboratories reporting resistance genes that were inappropriate for the organism recovered ranged between 2.0% - 67.0%.

Conclusions

Based on the results reported by participants in API’s proficiency event, Molecular Multiplex platforms are accurately identifying Gram positive resistance genes. However, many participants using both FDA approved and LDT systems reported results for resistance genes that were not applicable for the organism recovered. This inaccurate reporting could potentially lead to inappropriate antimicrobial therapies being prescribed.
A-299 Assessment of a new miniaturized line blot system for fully automated serodiagnosis of Borrelia infections
Authors: Sabalza M , Scheper T , Assmann J , Ott A , Schulz A , Meyer W
Published: October 2024

Background

Serodiagnosis of Lyme disease caused by Borrelia burgdorferi commonly affords the combination of a sensitive antibody screening test followed by confirmatory immunoblot analysis. We developed and evaluated a new immunoblot system enabling the multiparametric analysis of anti-Borrelia antibodies by means of miniaturized line blots in a fully automated microplate format.

Methods

The EUROMicroblots Anti-Borrelia (IgG and IgM, EUROIMMUN) are based on diagnostically relevant Borrelia-specific antigens. Diagnostic sensitivity was determined by analyzing 203 pre-characterized samples from patients with Lyme disease stratified by clinical picture and antibiotic treatment. Specificity was assessed using 168 sera from patients clinically diagnosed with rheumatic diseases. The reference range was analyzed using a control panel of 211 (IgG) and 210 (IgM) samples from healthy individuals, comprising 151 (IgG) and 150 (IgM) blood donors as well as 60 pregnant women (IgG, IgM). The Microwell Imager and EUROLineScan software (EUROIMMUN) were used for image acquisition and evaluation.

Results

Depending on the clinical category, the diagnostic sensitivity of the EUROMicroblots ranged from 68.0% in the early phase of infection to 100% (IgG/IgM combined) at a specificity of 86.9% (IgG) and 94.0% (IgM). The analysis of the panel of healthy control subjects revealed a prevalence of 10.9% (IgG) and 2.8% (IgM).

Conclusions

The new EUROMicroblot system enables high-throughput serodiagnosis of Borrelia infections due to the microplate format and automated processing and evaluation. Depending on clinical symptoms and treatment, the assays provide excellent diagnostic sensitivity and specificity for the detection of anti-Borrelia IgG and IgM.
A-301 Evaluation of Second-Generation Visby Medical Sexual Health Point-of-Care Test: Clinical Concordance, Analytical Error Rates, and Result Turnaround Time
Authors: Kelley B , Wockenfus A , Binnicker M , Karon B , Donato L
Published: October 2024

Background

Rapid testing for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis may be useful for antibiotic stewardship initiatives. Our institution recently implemented the second-generation Visby Medical Sexual Health Test (Visby Gen2) for rapid diagnosis of STIs in our emergency department. Here we (1) compared result concordance of the (Visby Gen2) to the first-generation Visby Medical Sexual Health Click Test (Visby Gen1), (2) compared assay failure rates of the Visby Gen1 to Gen2 tests, and (3) compared result turnaround time (TAT) for clinically ordered rapid STI tests to central laboratory STI results.

Methods

Accuracy was assessed using residual clinical samples in Aptima buffer submitted for routine molecular STI testing (C. trachomatis, N. gonorrhoeae, and T. vaginalis) in the central laboratory on the Panther platform (Hologic). Aptima samples were diluted 1:33 in Visby collection buffer prior to testing on the Visby cartridge. Clinically reported results were used as reference results. Diluted samples with discordant results were re-tested on the reference method and the result from the dilution was used in calculations. Assay failure rates were calculated as the number of failed assays compared to the total assays performed. TAT for rapid and central lab testing was calculated as time of sample received in laboratory to time verified in laboratory information system.

Results

For Visby Gen1 we observed negative concordance of 100% (41/41) for C. trachomatis, 97.5% (39/40) for N. gonorrhoeae, and 97.1% (34/35) for T. vaginalis. Positive concordance was 91.7% (11/12) for C. trachomatis, 100% (11/11) for N. gonorrhoeae, and 100% (17/17) for T. vaginalis. For Visby Gen1 we observed a 10.5% (12/114) cartridge failure rate. For Visby Gen2, we observed negative concordance of 100% (59/59) for C. trachomatis, 100% (63/63) for N. gonorrhoeae, and 100% (55/55) for T. vaginalis while positive concordance was 100% (10/10) for C. trachomatis, 100% (6/6) for N. gonorrhoeae, and 90.9% (10/11) for T. vaginalis. The Visby Gen2 assay displayed a 4.9% (4/81) cartridge failure rate. Six weeks after implementing the Visby Gen2 assay in our ED, rapid STI panel TAT was 0.48 hours on average (n=20). In the central laboratory the average TAT was 22.31 hours (n=7892).

Conclusions

Assay concordance to reference method was similar for Visby Gen1 and Gen2 assays. The cartridge failure rate improved by 46.7% with the Gen2 assay which should decrease the need to repeat testing due to assay failure. Result TAT decreased by 97.8% when comparing rapid Visby results to central laboratory. Therefore, Visby STI testing using the Gen2 assay can provide accuracy and rapid results likely to facilitate more rapid patient management.
A-335 Evaluation of the Next Generation i-STAT® Point of Care Prothrombin Time Test
Authors: Ball S , Hahn S , Kornfeld S F
Published: October 2024

Background

The i-STAT® PTplus cartridge contains a point of care prothrombin time (PT) test. The purpose of this study was to assess the performance of the i-STAT PTplus cartridge compared to other commercially available PT tests namely, Dade® Innovin® on the Sysmex® CS-2500 and the Roche CoaguChek®. The i-STAT® PTplus cartridge is a point of care whole blood test for the determination of prothrombin time. It is used to aid in the monitoring of patients receiving anticoagulant therapy with coumarin derivatives.

Methods

Venous and capillary whole blood specimens were prospectively collected with IRB approved informed consent from 222 subjects undergoing coumarin therapy and from subjects who were not on anticoagulant therapy at three clinical sites to span the reportable range of 0.8 - 8.0 INR. Both venous and capillary whole blood specimens were tested in duplicate on the i-STAT 1 Wireless Analyzer and were tested in singlicate on the Roche CoaguChek® device. Plasma from a citrated venous blood specimen obtained from the same subjects was tested in duplicate on the Sysmex® CS-2500 instrument.

Results

The Passing-Bablok regression results in the table below demonstrate international normalized ratio (INR) in the first replicate of the i-STAT PTplus cartridge versus the first replicate comparative device for venous and capillary whole blood.

Conclusions

This study demonstrates that the i-STAT® PTplus cartridge has good agreement to both laboratory and point of care commercially available PT tests when tested with venous and capillary whole blood from subjects not on anticoagulant therapy and subjects receiving coumarin therapy. The studies were funded by Abbott Laboratories.
A-340 Analysis of OrganOx Liver Perfusate at the Point-of-Care on the Abbott iSTAT and Nova Glucometer to Support Clinical Evaluations of Donor Livers Prior to Transplantation
Authors: Doe B , Gant-Kanegusuku A , Maggiore J
Published: October 2024

Background

The recently FDA-approved OrganOx Metra normothermic perfusion system for maintaining donor livers under physiologic conditions prior to transplantation comes equipped with a limited onboard blood gas analyzer for monitoring pO2, pCO2 and temperature. In clinical practice, however, additional biomarkers are used to assess the functional performance of the donor liver, including perfusate lactate clearance and glucose utilization. Liver perfusate contains a mixture of packed red blood cells, albumin, heparin, antibiotic, and solutions of amino acids and electrolytes and bile salts to support metabolic function, and is a specimen type that is not approved by the FDA. Implementation of the OrganOx Metra at Loyola University Medical Center (LUMC), a quaternary care transplant center, led to the validation of liver perfusate for the evaluation of glucose and lactate at the point-of-care (POC) using the Nova STATStrip Glucometer and Abbott iSTAT CG4 cartridge, respectively.

Methods

Lactate was measured on the Abbott iStat CG4 cartridge, and glucose which was measured using the Nova STATStrip Glucometer. Recovery studies were performed by mixing liver perfusate (non-centrifuged, n=16 independent specimen) with heparinized whole blood.

Results

The average recovery for the evaluation of lactate was 100% (range = 78 to 122%), and the average recovery for glucose was 109% (range = 93 to 112%).

Conclusions

Recovery studies evaluating matrix effect for the analysis of lactate (Abbott iSTAT, CG4) and glucose (Nova STATStrip) in liver perfusate indicate that the matrix of the perfusate does not affect the analytical accuracy, as compared to heparinized whole blood, the FDA-approved specimen type. Measurement of the OrganOx liver perfusate for lactate and glucose on these POC devices demonstrates reliable assessments to guide transplant teams in evaluating the viability of donor livers.
A-344 Delivering better and timely diagnosis for critical patients: POC clinical performance versus Central Laboratory assays in key cardiac markers
Authors: Aldunate J , Montecinos C , Gárate J , Vial M
Published: October 2024

Background

Cardiac markers are often used in critical settings, such as emergency department and coronary units. Clinica Redsalud Santiago implemented a reference Cardiovascular center to improve patient length of stay and clinical output, supported by diverse procedures and opportune diagnosis. Our aim was to implement POC devices for measuring key Cardiac Markers. Here we validated clinically and analytically the performance of POC devices versus Central Laboratory results for Troponin I, hs Troponin I, BNP and NT-proBNP markers.

Methods

Forty-nine patients admitted at emergency department were included in the study. Forty samples were obtained from male patients (69.7±9.8 years) and 9 from female patients (67.8±3.9 years). Samples were drawn and processed in parallel using Triage SOB panel, hsTroponin I and NT-proBNP tests, and the other samples were analyzed in a VITROS system, using Troponin I ES, hs Troponin I and NT-proBNP.

Results

Clinical agreement was assessed for different methodologies, using kappa values. Almost perfect agreement was achieved for Troponin I and NT-proBNP between Triage and VITROS systems (Figure 1). For harmonization results reporting purposes, regression fits and Bland-Altman plots were analyzed for both assays (data not shown). Hs Troponin methods did not show a good linear correlation fit, but it improves significantly on quadratic regression. For NT-proBNP methods, a good linear correlation was achieved. In both comparisons, major differences were observed for high values, while those values near to cut-off or low-to-mid in pathological range were comparable.

Conclusions

Timely decisions are important but is difficult to find perfect solutions for end-to-end needs. We identified two key cardiac biomarkers used routinely in emergency department and coronary care that can be harmonized for clinicians, in terms of quality and traceability. Based upon results, we can expect value discrepancies between different methodologies, hence the need for creating proper guidance for supporting key decisions for clinicians.
A-365 Rapid HIV testing and confirmation reflex testing integration in Laboratory Information System (LIS) using a point-of-care glucometer
Authors: Leung E K , Gabra M I , Mendoza R , Lee C , Xiao Y
Published: October 2024

Background

Point-of-care (POC) rapid testing for HIV antigen/antibody has aided in the rapid determination of HIV infection and initiating post-prophylaxis treatment. However, the molecular confirmation test needed to confirm positive POC HIV results is a send-out test at Children’s Hospital Los Angeles (CHLA). A 2021 internal POC survey identified 4.5% of positive screening test results that were missed or ordered the inappropriate confirmation test due to manual order entry errors.

Methods

We investigated the use of the NOVA StatStrip glucometer to record and transmit the results of the HIV 1/2 antigen/antibody test into the laboratory information system (LIS) through QML Telcor middleware. A new test entry was developed on the NOVA StatStrip glucometer and an automatic reflex rule was developed to allow the appropriate confirmation test to be automatically ordered to circumvent issues with manual order entry.

Results

The reflex rule was validated using the Abbott HIV 1/2 antigen/antibody test and results were recorded on the NOVA StatStrip glucometer. A positive result for HIV ½ antibodies would automatically order the confirmatory HIV 1/2 Ab differentiation test. A positive result for the HIV 1/2 p24 antigen would automatically order the HIV-1 RNA molecular test. If the POC HIV 1/2 test is positive for both antibodies and the antigen, both confirmatory tests will be automatically ordered. All confirmation test orders were successfully submitted through the LIS without errors.

Conclusions

POC testing using the HIV 1/2 antigen/antibody lateral flow immunoassay allows for rapid bedside or clinic screening for fast treatment response. Our laboratory demonstrated the effective use of glucometers to transmit, auto reflex to order confirmatory tests, and post results to the LIS, thus, reducing errors associated with manual send-out order entries.
B-023 Workflow evaluation of the new Siemens Atellica CI Analyzer
Authors: Rhea-McManus J , Abd Alla M , Barrionuevo-González M , Crneković K , Elkhodary H , Findeisen P , Kraft M , Lapeña García S , Mickeler S , Ruffing U , Ruiz-Alvarez M , Diabate D
Published: October 2024

Background

The Atellica® CI Analyzer, Model 1900 is an integrated clinical chemistry and immunoassay analyzer that has the same user interface, general workflow, and planned test menu to that of the larger Atellica® Solution. Atellica CI Analyzer also shares the same reagents and consumables as the Atellica Solution. The purpose of this study was to evaluate workflow performance of the Atellica CI Analyzer in a routine-like clinical laboratory setting.

Methods

The study was conducted at four international laboratory facilities over a four-month period. Basic throughput of the Atellica CI Analyzer was evaluated at each site by testing quality control (QC) and remnant anonymized patient samples using an 8:2 mixture of chemistry (ion selective electrolytes [IMT], clinical chemistry analytes) and immunochemistry assays. Additionally, the impact of interrupting routine testing for STAT high-sensitivity cardiac troponin samples was also evaluated. Daily, weekly, and monthly maintenance activities were observed, and data collected through direct observations, time and motion studies, and system run logs.

Results

The Atellica CI Analyzer aspirated patient samples in as little as two minutes (mins) with the time to first result for the mixed assay worklist ranging from 1 to 12 mins from the time of first barcode read. Across the four sites, the time to last result for the mixed assay worklist (average n=495 test results per site) ranged from 52 to 65 mins. The average turn around time (TAT) for high-sensitivity troponin was 9 mins from barcode read. Daily maintenance and QC activities for the Atellica CI Analyzer are comprised of both automated and manual activities. The average daily maintenance hands-on time was 3.6 min, ranging from 1.6 to 6.4 mins across the four sites. Daily QC preparation required <5 mins of hands-on time. The total average hands-on time to complete weekly maintenance for the Atellica CI Analyzer was 7.5 min.

Conclusions

The Atellica CI Analyzer demonstrated consistent system performance across all four study sites. Implementation of the Atellica CI Analyzer has the potential to increase laboratory efficiency given the minimal hands-on time required for daily and weekly maintenance activities and short TATs.
B-034 Performance Evaluation of the Total Bile Acids (TBA) Assay on Mindray BS-2800M Analyzer
Authors: Dai J , Cheng W , Jiang M , Wang J
Published: October 2024

Background

Bile acids (BA) are synthesized in the liver and secreted into bile. The function of BA is to promote absorption of lipids including fat-soluble vitamins. During liver diseases such as viral hepatitis and liver injury by hepatotoxic drugs, and cholestasis condition, BA secretion to bile is impaired, causing serum BA level to rise. Therefore, the determination of serum BA can be used as a sensitive indicator of liver function. TBA reagent contains NADH that requires pH ≥ 9 to be stable that is usually difficult to be maintained during reagent opened and stored on the analyzer. Meanwhile, 3α-Hydroxysteroid Dehydrogenase (3α-HSD) is required for the reaction. 3α-HSD is sensitive to pH condition. Minor changes in pH results in significant changes of enzyme activity. We formulated our TBA reagent with prolonged stability when reagent is onboard on the analyzer. This study evaluated the performance of the new Mindray TBA assay on Mindray BS-2800M.

Methods

TBA assay was based on the method with coupled Thio-NAD and NADH reaction for BA. The R1 contains Thio-NAD. The R2 contains NADH and 3α-HSD. R1 is incubated with serum sample containing BA for 5 min at 37°C and R2 is then added. During further incubation in the presence of Thio-NAD, 3α-HSD converts BA to 3-ketosteroids and Thio-NADH. The reaction is reversible, and 3α-HSD can convert 3-keto steroids and Thio-NADH to BA and Thio-NAD. In the presence of excess NADH, enzyme cycling occurs efficiently and the rate of formation of Thio-NADH is determined by measuring specific change of absorbance at 412 nm. Two-point-line calibration is used by this assay. The TBA concentrations for the test samples are obtained by the absorbances of test samples from the calibration line. The performances of precision, linearity, onboard stability, interference (hemolysis, lipid and bilirubin), correlation are evaluated following CLSI protocols.

Results

The precision study was run according to EP05A3 with two commercial controls (about 21 and 36μmol/L) and two serum sample pools(about 9.9 and 24.2 μmol/L)on the Mindray BS-2800M system. The repeatability and within-lab CVs ranged from 0.74% to 1.97%, respectively. The linearity of the assay was determined as from 2.0 μmol/L to 180 μmol/L. The reagent onboard stability is for 28 days without recalibration that is superior to TBA reagents from other manufacturers. The interference of hemolysis, lipid and bilirubin are with less than ±10% impact with hemolysate Hemoglobin up to 500 mg/dL, Intralipids up to 500 mg/dL, and Conjugated bilirubin up to 30 mg/dL, Unconjugated bilirubin up to 30mg/dL. This assay (Y) also correlated well with SEKISUI TBA assay (x), (Y = 0.9965X + 0.2694, r= 0.9993).

Conclusions

From this evaluation, we concluded that Mindray TBA assay can measure serum TBA precisely and accurately with good performances, especially for onboard stability. It is suitable for use in routine clinical laboratories.
B-039 Evaluating Inter-Analytic Module Immunoassay Carryover
Authors: Spiesman A M , Spriggs A , Légaré W , McShane A J
Published: October 2024

Background

Integrated analytical systems contain both clinical chemistry analyzers and immunoassay analyzers. Immunoassays can be assigned high priority based on potential sample carryover from sample probes used in clinical chemistry analyzers. The priority designation, assigned by the vendor, determines if the immunoassay test (disposable pipette) is sampled prior to the clinical chemistry test (non-disposable pipette). However, in a modern-day core chemistry laboratory, add-on testing is prevalent. High priority assignment by analytical systems is only effective when a specimen’s tests are analyzed concurrently and doesn’t account for an add-on of any high priority immunoassays. Evaluation of carryover for high priority immunoassays on clinical chemistry analyzers provides insight on if there is clinical impact of allowing add-on testing of these analytes.

Methods

Intact human chorionic gonadotropin + β-subunit (HCG-BETA, Roche Diagnostics, cobas e602), Procalcitonin (PCT, Roche Diagnostics, cobas e602), and Elecsys Total Prostate-specific Antigen (TPSA, Roche Diagnostics, cobas e602) were the high priority immunoassays evaluated for carryover. High and low target pools were separated into aliquots and baselines for each pool established. High sampling volume assays to potentially generate carryover on the clinical chemistry analyzers were determined to be Sodium (Na, Roche Diagnostics, cobas ISE), Unsaturated Iron-Binding Capacity (UIBC, Roche Diagnostics, cobas c702), and Ammonia (NH3L2, Roche Diagnostics, cobas c502). The ordering sequence of high pool to low pool was then assayed in triplicate on each clinical chemistry analyzer. After potential carryover had been generated, the low pool was again assayed for the immunoassays to evaluate if carryover had occurred and if the carryover exceeded the analyte’s allowable error. Statistical analysis was then performed utilizing Microsoft Excel.

Results

Conclusions

Add-on testing should be restricted for β-HCG and TPSA as a previous clinical chemistry analysis could lead to an errant add-on result due to carryover. PCT is unaffected by previous clinical chemistry analysis.
B-053 Four years summary of flow cytometry live cell based assay for detecting serum anti-aquaporin 4 IgG and anti-myelin oligodendrocyte glycoprotein IgG in a Korean reference laboratory
Authors: Moon S , Min J , Hahm C , Choi J , Oh G
Published: October 2024

Background

In the diagnosis of neuromyelitis optica spectrum disorder (NMOSD), it is important to sensitively detect anti-aquaporin 4 (AQP4) IgG and anti-myelin oligodenrocyte glycoprotein (MOG) IgG in patients' serum. NMOSD is a disease that shows 3-7 times more common prevalence in Far East Asia than in the West. According to the IPND diagnostic criteria, it is recommended to diagnose as a cell based assay using full length recombinant protein. In this study, we would like to review 4 years results of AQP4, MOG requested to Eone laboratories in Korea performed with flow cytometry live cell based assay (FC-CBA).

Methods

FC-CBA was performed using piRES2 cell transfected with AQP4, MOG and stained with DsRed2. Subcultured cells were counted with 10^6, and reacted with patients' serum for 1 hour in a refrigerated state. Thereafter, reaction with FITC anti-human IgG for 2nd antibody for 30 minutes, and 10,000 cells were read from Navius (Beckman Coulter). The mean fluorescence intensity (MFI) ratio , which is the ratio obtained by dividing the MFI value of both FITC and DsRed2 positive cells and DsRed2 positive cells to negative cells, was used to determine positive, borderline, and negative for the serum sample.

AQP4 reviewed cases during the period from November 2018 to January 2024, and MOG reviewed cases during the period from December 2019 to January 2024. Indirect immunofluorescence assay using formalin fixed cells is commercially available and compared to the FC-CBA of this institution.

Results

During the study period, 4,733 cases of AQP4 were performed, and 23,540 cases of MOG were performed by FC-CBA. Among them, AQP4 was positive in 405 cases (8.5%) and borderline in 71 cases (1.5%), and all others were negative. MOG was 2,597 positive (11%), borderline in 1,144 cases (4.8%), and all others were negative. The positive and borderline cutoffs for MFI ratio were changed during the study period, and the positive rate was significantly changed.

Conclusions

Eone laboratories are the only institution in Korea that performs live cell based assay using flow cytometry for AQP4 and MOG IgG, and receives samples from patients suspected of NMOSD at university hospitals. When reading with MFI ratio, it is important to properly set the cutoff to determine the positivity rate.
B-055 Comparison of two different methods for quantitation of anti-dsDNA antibody
Authors: Choi J , Oh G
Published: October 2024

Background

Anti-dsDNA antibody is a specific marker of rheumatic disorder, primarily systemic lupus erythematosus (SLE). Early detection of these diseases is most important in treatment and prognosis. We evaluated two different quantitation systems of anti-dsDNA antibody: the BioPlex 2200 multiplex simultaneous detect system and the single detection method, which is the Phadia 250 system.

Methods

53 serum samples were analyzed by two different methods, which are BioPlex 2200, Bio-Rad Laboratories, Hercules, CA, and Padia 250, Thermo Fisher Scientific, Uppsala, Sweden, respectively. The method of the BioPlex 2200 system is multiplexed bead assay, and that of Phadia 250 is Fluorescence Enzyme Immunoassay (FEIA).

Results

The quantitation results of BioPlexx 2200 were 1 to 126 IU/mL, and those from Phadia 250 were 0.08 to 109.53 IU/mL, respectively. These two groups of the anti-dsDNA antibody values showed excellent correlations (r=0.9036).

Conclusions

The quantitation of anti-dsDNA antibody were performed mainly by a single analyzing method, Phadia 250, in Korea. Bioplex 2200 system is multiplex bead assay; it can analyze eight different Extractable Nuclear Antigen Antibodies (anti-ENA) simultaneously: Anti Ribosomal P Ab, Anti SSa/Ro Ab, Anti SSb/La Ab, Anti Centromere Ab, Anti Sm Ab, Anti RNP Ab, Anti SCL-70 Ab, Anti Jo-1 Ab as well. Nevertheless, these anti-ENA results showed semiquantitative results.
B-116 Cost Estimation of Laboratory Test Overuse in 14 Ordered Parameters: Experience From 6 hospitals and 65 Primary Care Centers
Authors: Puigví L , Cebollero A , Ruiz M , Regidor D , Carbonell M , Miró S , Esteve C , Massaro M , Romero C , Mariné J , Guillén J , Miró J , París X , Benítez M
Published: October 2024

Background

Inappropriate retesting and test request are considered causes of laboratory overutilization. The former can be managed through minimum retesting intervals (MRI) and the latter with expert rules in the laboratory information system (LIS). The aim of this study was to assess the effectiveness of both tools.

Methods

We performed a retrospective analysis of 14 laboratory routine tests subject to MRI or expert rules among 6 hospitals and 65 primary care centers from March 2018 through December 2023. Both tools were gradually implemented in the LIS (Servolab4®, Siemens, Berlin, Germany). Data from an export software was used for analysis (Health Analytics, Siemens Healthineers, Madrid, Spain).

Results

During the observation period, a total of 493.640 tests requests were analyzed and 60.151 violations were counted (Table 1).

All violations represented an economic saving of 494.603€ (8.760€ per month). The most popular rejected test was 1,25-DihydroxyvitaminD (34,5%), followed by thyroid peroxidase antibodies (20,3%) and 25-HydroxyVitaminD (19%). These three tests were responsible for 73,8% of the total cost savings.

Conclusions

The real cost estimation of inappropriateness is difficult to assess, but the generated costs for the health system are certainly high and not negligible. Moreover, addressing overutilization would ensure standardization and high-quality care.
B-121 Optimizing Test Ordering: Leveraging Heuristics in Naming Conventions - A PSA Case Study
Authors: Orahoske C , Wu A , Lynch K
Published: October 2024

Background

A common screening test for prostate cancer is the Prostate-Specific Antigen (PSA) test, which may also be referred to as total PSA or total PSA plus free PSA, among other variations. Looking at the test menus of two major reference laboratories, it's apparent that PSA can be ordered under thirteen different test names. From an end-user perspective, the question arises: which of these thirteen tests should be ordered, and why are there so many options? This plethora of choices can lead to confusion and uncertainty for clinicians and patients alike. According to various guidelines, ordering Free PSA is only warranted when PSA values exceed 4 ng/ml. In such cases, the ratio of free PSA to total PSA can aid in further clinical decision-making and patient workup. At Zuckerberg San Francisco General Hospital (ZSFGH), we offer two tests for PSA. The first is named “Prostate Specific Antigen” is total PSA done in house, while the second is labeled “Prostate Spec. Ag. Total and Free.” which is sent out to a reference lab. Upon reviewing our send-out orders, we observed a significant increase (376%) from 2022 to 2023 in the use of the send out order.

Methods

The ordering data for our providers was collected from February 2022 to January 2024 for both in-house and send-out orders. The data was analyzed using descriptive statistics in Microsoft Excel.

Results

In our population, we observed an abnormal concentration of send-outs originating from a select group of physicians. Additional we also identified a group of providers who only selected the send out test order. Analysis of in-house assay results for PSA revealed that only 15% (1292 out of 8136) exceeded the cutoff of 4 ng/ml, necessitating further testing to inform clinical decision-making. Yet our send out volume of 4157 test is in discordance with how many PSA would need further evaluation. Based on a cost analysis reducing the send out volume by 80% could result in $53,210 savings. Therefore, to reduce the send out amount and to keep the naming convention similar we decided to implement a new test name that would reflex the PSA to Free PSA if the PSA is above 4 ng/ml. We decided on the name “Prostate Specific Antigen total with reflex to Free Prostate Specific Antigen”.

Conclusions

Our investigation into the variability in PSA test ordering revealed a significant disparity in the number of send-out orders, particularly originating from a select group of physicians. However, the disproportionately high volume of send-out tests suggested an inefficiency in the current testing approach. To address this issue and align with clinical guidelines, we decided to process a request to our medical executive committee for approval for this reflex test in order to meet reimbursement compliance with the Office of the Inspector General. This change aims to streamline the process, reduce unnecessary send-out tests, and ultimately improve the efficiency and accuracy of prostate cancer screening at our institution.
B-151 Development and Validation of Plasma Catecholamines by Mass Spectrometry
Authors: Kemp J , Taylor R , Maus A , Grebe S K
Published: October 2024

Background

Our established method for measuring plasma catecholamines utilized a Shimadzu HPLC coupled to an ESA Coulochem III electrochemical detector. Chromatographic run times were long, resulting in slow turnaround times. Instrument maintenance was labor intensive, and the assay was prone to interferences. To overcome these limitations, we changed the method to liquid chromatography-tandem mass spectrometry (LC-MS/MS) measurements.

Methods

After the addition of a labeled internal standard for each analyte, samples are loaded onto 50 mg of activated alumina at pH 8.6, utilizing a Tris-HCl, sodium carbonate and EDTA buffer. After incubation the alumina is then washed with 50% acetonitrile followed by water. Elution off the alumina is performed with 2% acetic acid. Derivatization is then performed on the eluate utilizing acetaldehyde and a cyanoborohydride buffer. Following derivatization, the samples are analyzed for epinephrine, norepinephrine, and dopamine by LC-MS/MS using a Sciex 7500 coupled to a ThermoFisher Scientific TLX-4 equipped with Vanquish pumps. Chromatographic separation was obtained using a Phenomenex Kinetex 2.6 um BiPhenyl 50x3 mm analytical column.

Results

Runtimes were significantly shorter than with the previous method, and no interferences were observed. Assay validation consisted of: intra/inter assay precision, accuracy, recovery, linearity, carryover, limit of detection (LOD), and interferences. Three levels were assessed for intra assay precision and each of the analytes monitored yielded %CVs of less than 6%. Four levels were assessed for inter assay precision and each of the analytes monitored yielded %CVs of less than 10%. When using linear regression analysis to compare results with the previous clinical assay, the slope, y-intercept and R2 were the following; dopamine: 1.06, 2.74, 0.978; epinephrine: 0.905, 2.20, 0.989; norepinephrine: 0.919, 9.75, 0.953. Spike and recovery from five samples yielded a mean average recovery of 93.4% for dopamine, 100% for epinephrine and 98.1% for norepinephrine. For linearity 4 samples were diluted and the mean % difference from expected was -1.66% for dopamine, -0.25% for epinephrine and 1.78% for norepinephrine. Blanks were injected following the high standard and carryover was negligible. LOD was determined by running a low sample pool along with a blank over 20 assays. The LOD was determined to be less than the LLOQ. Sixty-two common drugs/vitamins along with varying levels of hemolysis, lipemia, and bilirubin were also tested to ensure no interferences were seen.

Conclusions

The LC-MS/MS method exceeded the performance of the historical Shimdazu HPLC system with ESA Coluochem III electrochemical detector method. We anticipate that the better analytical performance will improve the testing quality of our patients.