Clinical Performance Research Articles

Evaluation of a plasma cell-free DNA methylation test for colorectal cancer diagnosis: a multicenter clinical study.

A blood-based diagnostic test is a promising strategy for colorectal cancer (CRC). The MethyDT test (IColohunter), which detects methylation levels of NTMT1 and MAP3K14-AS1, exhibited potential in discriminating CRC, but its clinical performance needs to be validated in large-scale populations. A multicenter, double-blinded, cross-sectional study that enrolled 1194 participants was performed. Plasma samples were collected to detect methylation levels of NTMT1 and MAP3K14-AS1 using quantitative methylation-specific PCR with the MethyDT test, and the accuracy was further evaluated by Sanger sequencing. The sensitivities of the MethyDT test for detecting CRC, early stages of CRC (I and II), advanced adenoma (AA), and high-grade intraepithelial neoplasia (HGIN) were 91.2% (95% confidence interval [CI], 88.4-94.0), 87.4% (95% CI, 82.5-92.2), 43.5% (95% CI, 35.7-51.4), and 72.7% (95% CI, 57.5-87.9), respectively. The specificities for participants with non-AA, interfering diseases (ID), and no evidence of disease (NED) were 85.0% (95% CI, 78.8-91.3), 93.7% (95% CI, 91.4-95.9) and 97.3% (95% CI, 90.5-99.7), respectively, and its overall specificity for all-controls was 92.4% (95% CI, 90.3-94.4). The consistency of the MethyDT test with pathology for CRC was high with a kappa value of 0.830 (95% CI, 0.795-0.865). Additionally, the MethyDT test was comparable to Sanger sequencing for detecting methylation with kappa values > 0.97. The MethyDT test demonstrates excellent sensitivity and specificity for CRC and high consistency with Sanger sequencing for methylation, suggesting it may serve as a potential noninvasive diagnostic tool for the detection of CRC. This clinical trial has been registered in ClinicalTrials.gov (NCT05508503).

Effect of artificial aging and different surface finishing protocols on the flexural strength and surface hardness of a photopolymer for manufacturing monolithic polychromatic complete dentures using PolyJet 3D printing.

This study evaluated the effect of thermocycling and three different surface finishing protocols on the flexural strength and surface hardness of a novel photopolymer intended for manufacturing monolithic polychromatic dental prostheses using PolyJet 3D printing. A total of 90 specimens were manufactured using a photopolymer for 3D printing monolithic polychromatic dental prostheses using PolyJet technology (TrueDent; Stratasys USA). The specimens were divided into three groups (n=30) according to the surface finishing protocol used: The control group Pumice+Moldent (Pumice), Pumice+Optiglaze (Optiglaze), and Polycril+Moldent (Polycril). Half of the specimens of each group (n=15) were subjected to 5000 thermocycles (Thermocycling Unit OMC350TSX; Odeme Dental Research, Santa Catarina, Brazil), The other half was stored in distilled water at room temperature for 7 days before testing. The flexural strength of the specimens was assessed in a universal testing machine (MTS Sintech ReNew; MTS Systems Corp, Aiden Prairie, MN), and the Vicker's surface hardness was evaluated with a microhardness tester (Micro indentation Hardness Tester LM247AT; Leco Instruments Ltd, Ontario, Canada). The resulting data was analyzed using two-way ANOVA tests, and Fisher's protected least significant differences (α=0.05) in a professional statistical analysis computer program (SAS v9.4, SAS Institute, Cary, NC) RESULTS: The two-way ANOVA tests suggested a statistically significant effect of thermocycling and the surface finishing protocol on the flexural strength (p=0.01) but without significant interaction between both independent variables (p=0.18). The post hoc analysis revealed no significant differences in the flexural strength between groups without thermocycling (p>0.05). Thermocycling decreased the flexural strength of all groups (p<0.05), and the Optiglaze group exhibited significantly higher flexural strength than the Polycril and Pumice groups after thermocycling (p<0.01). Regarding the surface hardness, the two-way ANOVA indicated a significant 2-way interaction between thermocycling and the surface of the finishing protocol (p=0.01). The post hoc analysis showed that the Optiglaze group had significantly higher hardness than the other groups, both before and after thermocycling (p<0.01) After thermocycling, a significant decrease in surface hardness was observed in the Polycril and Pumice groups (p<0.01). Surface finishing protocols and artificial aging can affect the surface hardness and flexural strength of the dental prostheses manufactured using the photopolymer studied. Careful polishing and surface finishing are required to ensure favorable clinical performance. Coating with a photopolymerizable glaze material seems to be a favorable surface treatment for monolithic polychromatic complete dentures fabricated using PolyJet 3D printing.

Utilizing Multi-layer Perceptron for Esophageal Cancer Classification Through Machine Learning Methods

Aims This research paper aims to check the effectiveness of a variety of machine learning models in classifying esophageal cancer through MRI scans. The current study encompasses Convolutional Neural Network (CNN), K-Nearest Neighbor (KNN), Recurrent Neural Network (RNN), and Visual Geometry Group 16 (VGG16), among others which are elaborated in this paper. This paper aims to identify the most accurate model to facilitate increased, improved diagnostic accuracy to revolutionize early detection methods for this dreadful disease. The ultimate goal is, therefore, to improve the clinical practice performance and its results with advanced machine learning techniques in medical diagnosis. Background Esophageal cancer poses a critical problem for medical oncologists since its pathology is quite complex, and the death rate is exceptionally high. Proper early detection is essential for effective treatment and improved survival. The results are positive, but the conventional diagnostic methods are not sensitive and have low specificity. Recent progress in machine learning methods brings a new possibility to high sensitivity and specificity in the diagnosis. This paper explores the potentiality of different machine-learning models in classifying esophageal cancer through MRI scans to complement the constraints of the traditional diagnostics approach. Objective This study is aimed at verifying whether CNN, KNN, RNN, and VGG16, amongst other advanced machine learning models, are effective in correctly classifying esophageal cancer from MRI scans. This review aims at establishing the diagnostic accuracy of all these models, with the best among all. It plays a role in developing early detection mechanisms that increase patient outcome confidence in the clinical setting. Methods This study applies the approach of comparative analysis by using four unique machine learning models to classify esophageal cancer from MRI scans. This was made possible through the intensive training and validation of the model using a standardized set of MRI data. The model’s effectiveness was assessed using performance evaluation metrics, which included accuracy, precision, recall, and F1 score. Results In classifying esophageal cancers from MRI scans, the current study found VGG16 to be an adequate model, with a high accuracy of 96.66%. CNN took the second position, with an accuracy of 94.5%, showing efficient results for spatial pattern recognition. The model of KNN and RNN also showed commendable performance, with accuracies of 91.44% and 88.97%, respectively, portraying their strengths in proximity-based learning and handling sequential data. These findings underline the potential to add significant value to the processes of esophageal cancer diagnosis using machine learning models. Conclusion The study concluded that machine learning techniques, mainly VGG16 and CNN, had a high potential for escalated diagnostic precision in classifying esophageal cancer from MRI imaging. VGG16 showed great accuracy, while CNN displayed advanced spatial detection, followed by KNN and RNN. Thus, the results set new opportunities for introducing advanced computational models to the clinics, which might transform strategies for early detection to improve patient-centered outcomes in oncology.

Feasibility and Performance of a Point-of-Care Hepatitis C RNA Assay in a Community Supervision Cohort

This cross-sectional study examines the feasibility and clinical performance of a fingerstick point-of-care hepatitis C virus (HCV) RNA assay in a community supervision (probation or parole) setting.

7007 Analytical &amp; Clinical Performance of a Novel Sensitive Rapid Bioassay for Thyrotropin Receptor Antibodies

Abstract Disclosure: P.D. Olivo: Consulting Fee; Self; QuidelOrtho, CA USA. H. Kim: Employee; Self; QuidelOrtho. L. Miao: Employee; Self; QuidelOrtho. J. Houtz: Employee; Self; QuidelOrtho. M. Luffy: None. J. Wolf: None. G.J. Kahaly: Grant Recipient; Self; QuidelOrtho, USA. Background: The role of stimulatory anti-TSH-R-Ab in the pathogenesis of autoimmune hyperthyroidism is well established. A novel and rapid cell-based bioassay, referred to as Turbo TSITM, for measurement of thyroid-stimulating autoantibodies (TSAb) was recently developed. An assessment of the analytical &amp; clinical performance of this bioassay is described herein. Methods: Turbo TSI greatly reduces the complexity and time required to measure TSAb. It avoids the need for cell culture, has no wash or lysis steps, and has a total turn-around-time of less than 90 minutes. Thawed cells from Turbo TSI kits were treated with different concentrations of a World Health Organization (WHO) international standard (IS) TSI or TSAb-positive serum. TSAb was measured as a function of luciferase activity measured as relative light units (RLU) and converted into international units per liter (IU/L). Two users at two sites performed analytical performance studies on numerous samples, over multiple days. Results: The limit of blank, limit of detection and limit of quantitation were determined to be 0.007 IU/L, 0.014 IU/L, and 0.021 IU/L, respectively. Receiver operator characteristics (ROC) analysis determined the cut-off to be 0.0241 IU/L with an area under the curve of 0.984. The linear range was shown to be from 0.015 to 11.958 IU/L. The intra-laboratory precision was ≤15 percent CV. The overall reproducibility of the assay was ≤20 percent CV for five concentrations (0.06 to 5.16 IU/L). Interference and cross reactivity studies with a variety of substances showed that the assay was robust. Turbo TSI demonstrated 95.2% (95% CI 83.3-98.1) sensitivity and 94.8% (95% CI 90.9-97.1) specificity when compared with an FDA-cleared bioassay (Thyretain® TSI) using serum from 295 patients with autoimmune thyroid disease (AITD). When testing 172 unselected, consecutive TSAb+ AITD patients, a US based, prospective, multicenter, blinded study showed a 98% concordance between Turbo TSI and Thyretain® TSI. When comparing Turbo TSI, Thyretain TSI and a TSH-R-Ab binding immunoassay (Cobas) in 670 unselected, consecutive, treated and untreated AITD subjects, sensitivity was 83%, 79% and 68%, respectively (Turbo vs. Cobas, P&amp;lt;0.001). Furthermore, testing 84 patients with naïve, untreated Graves’ hyperthyroidism, detection of TSH-R-Ab was 100%, 98% and 92%, respectively (Turbo TSI vs binding assay, P&amp;lt;0.01). Finally, 95% vs. 73% of 332 patients with Graves’ orbitopathy were TSH-R-Ab+ with Turbo TSI vs. binding assay (P&amp;lt;0.001). Conclusions: The Turbo TSI bioassay exhibits excellent analytical &amp; clinical performance, a high level of reproducibility, and compares well with the FDA-cleared Thyretain® TSI. Presentation: 6/1/2024

Blood flow modulation to improve motor and neurophysiological outcomes in individuals with stroke: a scoping review.

Ischemic Conditioning (IC) is a procedure involving brief periods of occlusion followed by reperfusion in stationary limbs. Blood Flow Restriction with Exercise (BFR-E) is a technique comprising blood flow restriction during aerobic or resistance exercise. Both IC and BFR-E are Blood Flow Modulation (BFM) strategies that have shown promise across various health domains and are clinically relevant for stroke rehabilitation. Despite their potential benefits, our knowledge on the application and efficacy of either intervention in stroke is limited. This scoping review aims to synthesize the existing literature on the impact of IC and BFR-E on motor and neurophysiological outcomes in individuals post-stroke. Evidence from five studies displayed enhancements in paretic leg strength, gait speed, and paretic leg fatiguability after IC. Additionally, BFR-E led to improvements in clinical performance, gait parameters, and serum lactate levels. While trends toward motor function improvement were observed post-intervention, statistically significant differences were limited. Neurophysiological changes showed inconclusive results. Our review suggests that IC and BFR-E are promising clinical approaches in stroke, however high-quality studies focusing on neurophysiological mechanisms are required to establish the efficacy and underlying mechanisms of both in stroke. Recommendations regarding future directions and clinical utility are provided.

12423 Pre-treatment Blood Transcriptome Accurately Predicts Growth Response To Daily And Weekly GH Treatment In Children Born Small For Gestational Age

Abstract Disclosure: T. Garner: Grant Recipient; Self; Novo Nordisk. P. Murray: Grant Recipient; Self; Novo Nordisk. M. Hojby: Employee; Self; Novo Nordisk. Stock Owner; Self; Novo Nordisk. R. Ard: Employee; Self; Novo Nordisk. Stock Owner; Self; Novo Nordisk. P.E. Clayton: Grant Recipient; Self; Novo Nordisk. A. Stevens: Grant Recipient; Self; Novo Nordisk. Background: Predicting GH therapy response from gene expression has the potential to improve clinical management of short stature. Treatment in children born small for gestational age (SGA) requires daily GH injections. Although no long-acting GHs (LAGHs) are currently approved for SGA, results from REAL5 (randomised, multinational, open-label, controlled, phase 2 trial; NCT03878446) indicate that the LAGH somapacitan has an efficacy, safety, and tolerability profile similar to daily GH (1). Here, we investigate growth response prediction based on the baseline blood transcriptome with and without clinical variables in daily GH- or somapacitan-treated children in REAL5. Methods: REAL5 tested three somapacitan doses (0.16, 0.20, &amp; 0.24 mg/kg/week; n=12, n=13, &amp; n=12, respectively) versus two daily GH doses (0.035 &amp; 0.067 mg/kg/day; n=12 &amp; n=13, respectively). GH response was explored using four metrics calculated over 52-weeks: height velocity (HV; cm/year), HV standard deviation score (SDS), change in height SDS, and change in IGF-I SDS. Due to small sample sizes, dose groups were combined. Participants were split into tertiles to define fastest/slowest responders to each treatment which were compared to remaining tertiles. Differentially expressed genes (DEGs) were defined to distinguish one tertile from the remaining two. Random forest (RF) models were generated using the top 100 DEGs as well as in combination with a set of clinical variables. Area under the curve (AUC) describes RF prediction accuracy: for somapacitan sufficient samples were available for both training and validation while for daily growth hormone samples were only sufficient for training generating out of bag (OOB) AUCs, accompanied by error rates (ER). Accuracies were calculated for both fast &amp; slow responders across all response metrics in each treatment. Results: We demonstrate excellent predictive ability of the transcriptome to identify SGA children who respond slowest in HV following treatment with either daily GH or somapacitan (OOB AUC (ER)= 1.0 (5.0%) &amp; 0.99 (6.9%), respectively; validation AUC=0.812 for somapacitan), while prediction of other response measures was highly variable, particularly in validation (AUCs=0.56-1.0). The clinical variables combined with the transcriptomic data resulted in reduced accuracies and increased error rates (OOBs AUC(ER)=0.93(25%) [daily] &amp; 0.90(19%) [somapacitan]). Conclusions: In the first use of transcriptomics for growth response prediction in children born SGA we show good performance for those treated with both daily and weekly GH. However, when the transcriptome is combined with clinical data performance is reduced, indicating the importance of gene expression signatures for GH-response prediction. These findings may be promising for personalizing dose in GH-treated SGA patients. (1) Juul et al. EJE 2023:188,19-30. Presentation: 6/3/2024

Clinical performance of zirconia-based tooth-supported fixed dental prostheses: A systematic review and meta-analysis

ObjectivesThis study aimed to investigate the clinical performance of zirconia-based fixed dental prostheses (FDPs) in comparison to metal-ceramic (MC) FDPs. MethodsA comprehensive search on MEDLINE (PubMed), Web of Science (Core Collection), Scopus up to June 2024 was conducted. Studies that compared the success, survival and complication rates between zirconia based FDPs and MC FDPs were eligible for inclusion. ResultsThirty-one articles were identified, of which 22 were included for systematic review and 7 RCTs were included for meta-analysis. 10, 9 and 3 studies were classified to mean follow-up ≤ 5 years, 5 years < mean Follow-up ≤ 10 years, mean Follow-up >10 years, respectively. In the pooled analysis, 180 bilaminar zirconia (ZC) FDPs and 206 MC FDPs were included. ZC FDPs were significantly associated with more failures (RR=3.64, p = 0.009) and more Ceramic Chipping (RR=2.92, p < 0.0001) when compared to MC FDPs. Higher risks of Framework Fracture (RR=4.57, p = 0.18), Loss of Retention (RR=4.79, p = 0.17), Secondary Caries (RR=1.25, p = 0.68), Endodontic complications (RR=1.30, p = 0.74) and Marginal Integrity (RR=1.07, p = 0.88) were also found in ZC FDPs when compared to those of MC FDPs, but with no statistical difference. ConclusionThe current evidence continues to support the preference for traditional MC FDPs over ZC FDPs. Studies indicate that ZC FDPs have higher failure rates and more complications compared to MC FDPs, with ceramic chipping being a significant concern. There is lack of long term (>10 years follow-up) evidence of the clinical performance of ZC FDPs and monolithic zirconia FDPs. Clinical significanceThe study suggests that despite the growing popularity of zirconia, evidence shows MC FDPs may still be considered preferable to ZC FDPs.

Evaluation of the Microscanner C3 for Automated Cell Counting in Cerebrospinal Fluid Analysis

Background: Cerebrospinal fluid (CSF) analysis is essential for diagnosing various disorders affecting the central nervous system (CNS). Traditionally, CSF cell count analysis is performed manually using a Neubauer chamber hemocytometer, which is labor-intensive and prone to subjective interpretation. Methods: In this study, we evaluated the analytical and clinical performance of the Microscanner C3, an automated cell counting system, for CSF analysis using artificially prepared samples and 150 clinical CSF samples. Results: The lowest detectable white blood cell (WBC) count was 3.33 cells/µL, and the lowest detectable red blood cell (RBC) count was 3.67 cells/µL. The coefficients of variation (CV%) for the Microscanner C3 were lower than those for the Neubauer chamber at all cell concentrations. The correlation coefficients (R) between the Microscanner C3 and conventional methods were high: 0.9377 for WBCs and 0.9952 for RBCs when compared with the Neubauer chamber, and 0.8782 for WBCs and 0.9759 for RBCs when compared with the flow cytometer. Additionally, the Microscanner C3 showed good agreement with both the Neubauer chamber and flow cytometer in the Passing–Bablok regression analysis and Bland–Altman analysis for WBC count at all concentrations and RBC count at concentrations of 0–1000 cells/µL. Conclusions: The Microscanner C3 proved to be more sensitive, precise, and consistent compared to the conventional hemocytometer. The new system is also compact, convenient, and cost-effective, making it a valuable option for clinical laboratories.

Smartphone Addiction: Impact, Challenges, and Effects on Cognition Skills among the Dental Students in the Kingdom of Saudi Arabia

Abstract Objective Smartphones are multifunctional devices providing a range of beneficial technologies and applications that support communication, socialization, entertainment, and education but also have a few disadvantages related to overdependence among students in general and more specifically with its effects seen in cognition among professional ones such as dental students. This study aims to explore the effect of smartphones on the academic and clinical performance of undergraduate and internship dental students in universities of the Kingdom of Saudi Arabia. Materials and Methods In this cross-sectional study, the data were collected using 32 questionnaire-based Google forms which the concerned academic level students filled. The first part included 5 questions related to demographic data, while the second part included 24 questions assessing smartphone addiction and its impact on academic performance; furthermore, the last part of the survey has 3 questions inquiring about the effect of smartphones on clinical performance. Results Five-point Likert scale was used which has shown that as the level of study increases, smartphone use has also increased gradually. There was a positive correlation to the ill effects of high use of smartphones ranging from the patient himself experiencing high use of his device and often leading to lack of sleep. In contrast, some positive outcomes were related to the participants not using their devices while in the clinical atmosphere largely associated with the strict infection control protocol and self-awareness. Discussion Our findings can be correlated to various other studies that highlight the peers telling the participants about the increased risk of their smartphones and the same being felt by themselves. This highlights a positive result in the awareness campaigns being carried out and the main effect has been related to lack of sleep. A high infection control protocol can limit the dependency of the students on smartphone use among the clinics, but this does not relieve the overall high-level use among dental students. Conclusion An attempt should be made to educate the young population about the bad effects of the smartphone especially long hours of usage, bad timing, overdependence, and psychological impact. More studies are needed to assess the psychological impact of smartphone usage among this population.

Diagnostic accuracy of rapid antigen tests for detection of Delta and Omicron variants of severe acute respiratory syndrome coronavirus 2: Direct evidence from prospective clinical settings.

Despite widespread application during the coronavirus disease-19 pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection using patient-performed rapid antigen tests (RATs) is limited, especially regarding the Delta and Omicron variants. Therefore, in this study, we evaluated the performance of RATs in identifying Delta and Omicron infections in self-test settings. In this multicenter clinical performance study conducted in Korea between November 2021 and February 2022, we included participants without prior diagnostic device experience. Using 2 RAT types, we compared the results with real-time reverse transcriptase-polymerase chain reaction testing, focusing on clinical sensitivity and specificity. Reverse transcriptase-polymerase chain reaction helped confirm 77 SARS-CoV-2 infections among 280 participants. RATs exhibited high positive agreement for Omicron detection but lower rates for Delta, especially among partially vaccinated individuals. This study provides direct evidence that RATs, originally developed for ancestral strains of SARS-CoV-2, effectively detect major variants such as Delta and Omicron in real patient/clinical settings. By confirming variant presence through sequencing, our research offers significant and novel insights into the performance of RATs, particularly in the context of breakthrough infections postvaccination, with precise data on vaccination status and timing obtained from government records.

Full-arch prostheses supported by implants with different macrostructures: A multicenter randomized controlled trial.

This study evaluates the clinical performance of implants with hydrophilic surface and two different macrostructures: cylindrical with perforating triangular threads (CT) and cylindrical-tapered with the association of square and condensing and perforating triangular threads (TST). This was a multicenter split-mouth, simple-blinded, randomized, and controlled trial. Thirty patients with edentulous mandible received two CT and two TST implants. Primary stability was determined by insertion torque and resonance frequency analysis (RFA). Implants were loaded with full fixed-arch prostheses within 24 h after insertion. Clinical parameters (visible plaque index, marginal bleeding index; bleeding on probing; probing depth; and clinical attachment level) and the RFA were assessed at 2, 6, 12, and 24 months after implant loading. Marginal bone level changes were measured by comparison of standardized radiographs taken on the day of implant placement and 6, 12, and 24 months thereafter. Twenty-eight patients completed the 2-year follow-up. The survival rates were 99.16% for CT implants and 100% for TST implants. One CT implant was lost until the 2 months follow-up. No significant differences were found between the two implant types for marginal bone level changes (CT 0.34 [0.24; 0.55 mm]; 0.33 [0.18; 0.55 mm]; 0.41 [0.12; 0.7 mm] vs TST 0.36 [0.14; 0.74 mm]; 0.33 [0.23; 0.63 mm]; 0.30 [0.20; 0.64 mm] at 6, 12, and 24 months, respectively) and other clinical parameters. The macrostructure of the implants had no influence on survival rate, primary and secondary stability, marginal bone level changes, and peri-implant clinical parameters outcomes. Both implants can be predictably used for immediate loading of full-arch mandibular prostheses.

Clinical validation of the Roche cobas HPV test on the Roche cobas 5800 system for the purpose of cervical screening.

This study assessed the relative clinical sensitivity and specificity, as well as reproducibility, for high-risk HPV types of the Roche cobas HPV test when processed using the Roche cobas 5800 system. The results from this study demonstrate that the cobas HPV test using the cobas 5800 system fulfils the Meijer criteria for use in population-based cervical screening. This clinical validation study also examines the clinical sensitivity and specificity based on partial genotyping, with separate detection of HPV16 and HPV18, compared with the Roche cobas 4800 HPV test, a second-generation standard comparator assay. The cobas HPV test has a relative clinical sensitivity of 1.000, when compared with the cobas 4800 HPV test to detect histologically confirmed CIN2+ lesions in woman aged 30 years or older, with a relative clinical specificity of 0.995. The general intra- and inter-laboratory agreement for the cobas HPV test on the cobas 5800 system for finding a HPV positive result were 99.1% and 99.6%, respectively.IMPORTANCEThis study demonstrates, for the first time, the clinical performance of the Roche cobas HPV test when processed using the new cobas 5800 system [cobas (5800)]. This study shows that the cobas (5800) demonstrates relative clinical sensitivity and specificity, when compared with a standard comparator HPV test, which meets the international HPV test validation requirements. Intra- and inter-laboratory reproducibility also fulfills these criteria. The current study demonstrates that the cobas (5800) can be used for primary HPV-based cervical screening on cervical specimens.

A-048 Reference Interval and Clinical Performance Studies for Vitros® Immunodiagnostic Products Intact PTH II Assay to Aid in Diagnosis of Calcium and Parathyroid Disorders and Intraoperative Testing

Abstract Background Intact parathyroid hormone (iPTH) measurements aid in the differential diagnosis of hypercalcemia, hypocalcemia, and parathyroid disorders. The National Academy of Clinical Biochemistry has established guidelines for intraoperative PTH testing to monitor surgical success during parathyroidectomies. Studies were conducted to define the reference interval and clinical performance of the Vitros Immunodiagnostic Products Intact PTH II (Vitros iPTH II) assay, using samples from healthy individuals and patients with conditions commonly requiring iPTH testing, including intraoperative cases. Methods The reference interval study was conducted in accordance with Clinical and Laboratory Standards Institute (CLSI) guideline EP28-A3c in serum samples from 134 healthy individuals. For the clinical performance study, serum samples from individuals with hypoparathyroidism, primary hyperparathyroidism, chronic renal failure (secondary or tertiary hyperparathyroidism), hypercalcemia, hypercalcemia of malignancies, and hypocalcemia were tested. Intraoperative samples used were collected from parathyroidectomy patients in series at each surgical timepoint along with the standard plasma samples used to determine surgical success. Results The reference samples were composed of 134 serum donors that met all inclusion/exclusion criteria for healthy donors and had a normal test result on calcium, TSH, alkaline phosphatase, creatinine, and phosphate assays. The reference interval for iPTH was determined to be 14.2-75.2 pg/mL. The results in various disease states demonstrated the clinical performance of the Vitros iPTH II assay. Of 32 intraoperative sample series included in the study, three samples demonstrated no intraoperative decrease in iPTH due to surgical failures. Consistent with the goal of the parathyroidectomy procedure, at least a 50% decrease in iPTH was observed between the presurgical and post-excision samples in all other sample series. The clinical concordance with the Roche PTH assay used intraoperatively in these procedures was 100%. Conclusions Defining the reference interval for a normal healthy population and results from the intended use population demonstrated that the Vitros iPTH II assay can be used as an aid in the diagnosis of calcium and parathyroid disorders and intraoperative testing.

A-359 Clinical Performance Evaluation of the Polymerase Chain Reaction (PCR)-Based cobas CT/NG/MG Test for Use on the cobas liat System in a Clinical Laboratory Setting and Point-of-Care (POC) Location

Abstract Background Screening for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Mycoplasma genitalium (MG) can be achieved rapidly (in approximately 20 minutes) with the cobas® CT/NG/MG test (assay not cleared by US FDA. Submission currently under review and subject to change per health authority feedback). This automated, qualitative, real-time PCR-based nucleic acid amplification test (NAAT) is for use on the cobas® liat® system. This study evaluated the test’s clinical performance using urogenital samples from symptomatic and asymptomatic patients. Methods This non-interventional, non-observational study used prospective clinician-collected and self-collected specimens (urine, and vaginal swabs, all in cobas® PCR Media) from symptomatic/asymptomatic patients ≥14 years old from 13 POC sites across the US. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of cobas liat CT/NG/MG were calculated with respect to patient infected status (PIS), as determined using results from three FDA-approved NAATs and one laboratory-developed test. Due to insufficient positive NG samples during the trial period, further testing used archived samples. Results The median (range) age of the study population (N=4,800) was 35.0 (15.0-81.0) years; 40.4% (n=1,941) were symptomatic and 51.9% (n=2,489) were assigned female at birth. The cobas CT/NG/MG nucleic acid test demonstrated good clinical performance (Table 1). Across all specimen types, specificity was &amp;gt;97% for each analyte. Sensitivity was ≥95%, except in female urine (CT 87.0%, NG 93.1%, MG 78.9%). Regardless of specimen type, PPV and NPV were ≥95% for CT and NG; PPV for MG was highest in male urine (92.7%) and NPV was &amp;gt;97.5% across analytes. Conclusions In a clinical setting, the cobas CT/NG/MG nucleic acid test showed good clinical performance for the detection of CT, NG, and MG in urogenital samples, in addition to providing a short turn-around time and centralized testing lab quality at the POC for both self- and clinician-collected samples.

B-056 Clinical and Analytical Performance Evaluation of Two Immunoassays for the Detection of Mite Specific Serum IgE for Allergy Diagnosis

Abstract Background IgE-mediated allergic diseases can be considered a modern epidemic, with exponential growth mainly in industrialized countries. Diagnosis is usually based on detailed medical history, physical examination, skin or challenge test and the determination of allergen-specific serum IgE - a laboratory test that has become a high-value tool in the allergy patient's journey over the last three decades. As the identification of specific immunoglobulin E (sIgE) for a given allergen is important to aid in the allergy diagnosis, several methods for detecting IgE in vitro are available worldwide and, in recent years, there have been several improvements in laboratory methodologies bringing greater advances in terms of clinical and analytical performance. The study aims to evaluate the clinical performance and correlation between two different sIgE assays (IMMULITE® 2000 3gAllergy™ and ImmunoCAP) and their concordance with Skin Prick Test (SPT) and clinical history. Methods This prospective study was conducted with approximately 130 consecutive patients who underwent evaluation of allergic diseases in different centers in Brazil. Clinical data, blood samples, and SPT results were collected. With the blood samples, the allergens D1, D2 and D201 were evaluated using both methods (IMMULITE® 2000 3gAllergy™ and ImmunoCAP) and the data were evaluated in a correlation study and clinical concordance analysis. Results Qualitatively evaluating the sIgE results between the two immunoassays, at the cutoff point considered clinically significant (≥ 0.35 KU/L), a total agreement of 95.2% (D1); 95.1% (D2), 91.7% (D201) and 96.8% (Derp2) was observed. Semi-quantitatively evaluating through reactive interpretation, an agreement of 89.5% (D1); 91.06% (D2); 87.60% (D201) and 93.33% (Derp2) was observed. Spearman's correlation between the analytical methods was 0.85 (D1), 0.93 (D2), 0.68 (D201) and 0.76 (Derp2). When compared with the SPT results, a total agreement of 78.7% and 80.1% was obtained for 3gAllergy and ImmunoCAP, respectively, with slightly higher positive agreement for both methods. Conclusions The two methods have good agreement with each other, with greater differences when evaluated quantitatively. However, when compared to clinical history and skin prick test results, both perform very similarly with a few differences that may be caused by the difference in the assay design.

A-313 Use of the Preeclampsia Ratio in the Prognosis of Preterm Delivery and Adverse Outcomes

Abstract Background Preeclampsia (PE) is a hypertensive disorder of pregnancy that is characterized by high blood pressure and end-organ dysfunction with or without proteinuria after 20 weeks gestation. PE occurs in 6-8% of pregnancies and contributes to significant fetal, neonatal, and maternal morbidity and mortality. The ratio of two angiogenic placental proteins, soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF), are used in the management of PE. The purpose of this study was to evaluate use of the sFlt-1/PlGF ratio (PE ratio) generated using the ADVIA Centaur® and Atellica® IM sFlt-1 assay and the ADVIA Centaur and Atellica IM PlGF assays in the prognosis of preterm delivery and adverse outcomes in women presenting with signs and symptoms of PE. Methods A total of 654 females with singleton pregnancies between gestational weeks 20+0 days and 35+6 days and who had signs and symptoms of PE, but without severe features of PE were enrolled at 24 collection sites and followed prospectively for two weeks. Serum samples were collected at enrollment and adverse outcomes that included preterm delivery were prospectively collected within the two weeks after enrollment. Serum samples from approximately half of the population (n=316) were tested in singlicate using the sFlt-1 and PlGF assays on the ADVIA Centaur system in a derivation study that determined the optimal cutoff of the PE ratio in relation to adverse outcome. The remaining serum samples (n=338) were subsequently tested on the ADVIA Centaur system in a cut-off validation study that evaluated the clinical performance (sensitivity [SE], specificity [SP], positive predictive value [PPV], negative predictive value [NPV]) of the PE ratio at the derived cutoff in relation to adverse outcome. Method comparison studies were performed between the ADVIA Centaur versus the Roche Elecsys sFlt-1 and PlGF assays (n=255) and the ADVIA Centaur versus the Atellica IM sFlt-1 and PlGF assays (n=316). Results The rate of maternal adverse outcomes within two weeks was similar in the derivation study (32.3%) and validation study (28.1%). Using a receiver operating characteristic (ROC) curve analysis with the derivation cohort, a derived cutoff of 38 showed optimal clinical performance of the PE ratio in relation to adverse outcome (SE=72.5%, SP=94.7%, PPV=84.6%, NPV=89.5%). Similar clinical performance results of the PE ratio at the cutoff of 38 in relation to adverse outcome were found with the verification cohort (SE=88.42%, SP=87.65%, PPV=73.68%, NPV=95.09%). Weighted Deming regression analysis demonstrated equivalency between the Centaur, Roche, and Atellica PE ratios with correlation coefficients (r) of 0.9242 (Centaur vs Roche) and 0.995 (Centaur vs Atellica). Conclusions Measurement of sFlt-1 and PlGF to determine PE ratio can be performed on either the ADVIA Centaur or Atellica Analyzer and can be used to identify women presenting with PE or signs and symptoms of PE who are at high risk of experiencing an adverse event in the subsequent two weeks. Not available for sale in the U.S.A. The products/features mentioned herein are not commercially available in all countries. Their future availability cannot be guaranteed.

B-171 Iohexol Mass Spectrometry Method Validation and Comparison in Clinical Pediatric Laboratory

Abstract Background Accurate assessment of kidney function is important yet challenging in pediatric patients due to changing muscle mass affecting serum creatinine. There are several key methods to assess kidney function in this population, including estimated glomerular filtration rate (eGFR) from serum creatinine, urine creatinine clearance, and eGFR from serum iohexol clearance, which often provides a more reliable estimate. Iohexol is a non-ionic iodinated contrast agent filtered freely through the glomeruli without tubular secretion, making it an ideal GFR marker.In this study, we validated the LC-MS/MS method to quantitatively measure iohexol in clinical pediatric plasma and serum samples. The clinical performance was compared with the novel Verispray method. Methods A series of iohexol standards (Caymen Chemical) were prepared at 10, 100, 500, 1000 µg/mL in serum (UTAK). The liquid chromatography-tandem mass spectrometry (LC-MS/MS) method and Verispray method were developed to quantitatively measure iohexol concentrations in spiked pediatric specimens. The internal standard (IS) solution was prepared with Iohexol-D5 (Cayman Chemical) at 9 µg/mL in UPLC grade methanol. Specimen or calibration/QC (50 µL) were mixed with IS solution (450 µL), and then centrifuged at 14,000xg for 3 minutes. The supernatants were analyzed. For LC-MS/MS, 3 µL supernatants were chromatographed on a AccucoreTM Vanquish C18 50 x 2.1mm (Thermo Scientific) using a gradient of water with 0.1% formic acid (FA) against methanol with 0.1% FA. Iohexol and IS were measured by multiple reaction monitoring using a TSQ Quantis Plus Mass Spectrometer (ThermoFisher). For Verispray, 10 µL supernatants were loaded on the Verispray sample plate (ThermoFisher) without LC portion. The samples were extracted from the plate paper using 95% acetonitrile with 5% water and 0.1% FA before directly injected into the mass spectrometer. The LC-MS/MS method was evaluated for linearity, patient comparison, carryover, matrix effect, and stability. 40 patients were analyzed between methods. Results Linearity was assessed over 5 days at 4 calibrator levels, the coefficient of variation (CV) ranged from 3.46 - 5.99%. The patient comparison of 40, 20 serum and plasma respectively, was conducted with Mayo Clinics, and good concordance was observed. Matrix effects were evaluated with spiked samples prepared with 50% mobile phase A and B, the ion enhancement was at 10.7%, within the allowable limits. No significant carryover was seen. The samples were stable at room temperature for 48 hours and 4oC for 7 days. Freezing is not recommended. The comparison between Verispray and LC-MS/MS showed significant bias between and within the performing personnel, the deviation can be up to 40% comparing to LC-MS/MS method. Conclusions The LC-MS/MS method demonstrated stable and consistent analytical performance for iohexol measurement. However, the Verispray method showed significant inter- and intra-user variabilities. As the Verispray sample spot can only be used once, respotting is required for any additional measurement, reducing reproductivity. It is highly recommended to duplicate all samples when using Verispray, to limit preparation to one user per patient run. Overall, our validation indicates the LC-MS/MS method provides reliable performance as a useful alternative to other complex gold standard pediatric tests of kidney function.

Innovative COVID-19 Point-of-Care Diagnostics Suitable for Tuberculosis Diagnosis: A Scoping Review.

Rapid and accurate point-of-care (POC) tuberculosis (TB) diagnostics are crucial to bridge the TB diagnostic gap. Leveraging recent advancements in COVID-19 diagnostics, we explored adapting commercially available POC SARS-CoV-2 tests for TB diagnosis in line with the World Health Organization (WHO) target product profiles (TPPs). A scoping review was conducted following PRISMA-ScR guidelines to systematically map POC antigen and molecular SARS-CoV-2 diagnostic tests potentially meeting the TPPs for TB diagnostic tests for peripheral settings. Data were gathered from PubMed/MEDLINE, bioRxiv, medRxiv, publicly accessible in vitro diagnostic test databases, and developer websites up to 23 November 2022. Data on developer attributes, operational characteristics, pricing, clinical performance, and regulatory status were charted using standardized data extraction forms and evaluated with a standardized scorecard. A narrative synthesis of the data is presented. Our search yielded 2003 reports, with 408 meeting eligibility criteria. Among these, we identified 66 commercialized devices: 22 near-POC antigen tests, 1 POC molecular test, 31 near-POC molecular tests, and 12 low-complexity molecular tests potentially adaptable for TB. The highest-scoring SARS-CoV-2 diagnostic tests were the near-POC antigen platform LumiraDx (Roche, Basel, Switzerland), the POC molecular test Lucira Check-It (Pfizer, New York, NY, USA), the near-POC molecular test Visby (Visby, San Jose, CA, USA), and the low-complexity molecular platform Idylla (Biocartis, Lausanne, Switzerland). We highlight a diverse landscape of commercially available diagnostic tests suitable for potential adaptation to peripheral TB testing. This work aims to bolster global TB initiatives by fostering stakeholder collaboration, leveraging SARS-CoV-2 diagnostic technologies for TB, and uncovering new commercial avenues to tackle longstanding challenges in TB diagnosis.

B-207 Clinical Evaluation of ExiStation™ FA 96 RV for the detection of human respiratory viruses in human nasopharyngeal swab specimen

Abstract Background There has been growing demand for fully automated multiplex testing of respiratory viruses in molecular diagnostics following the COVID-19 pandemic. ExiStation™ FA 96 RV developed by BIONEER is a multiplex real-time RT-PCR assay. It is designed for the simultaneous detection and differentiation of SARS-CoV-2, Influenza A, Influenza B, and RSV RNA in human nasopharyngeal swab specimens from individuals showing signs and symptoms of respiratory viral infection. ExiStation™ FA 96 automates the entire process from RNA extraction to real-time RT-PCR for up to 96 samples at once within 100 minutes. Moreover, the system is equipped to decap sample tubes, eliminating the need for handling sample transport media. In this study, the clinical performance of the ExiStation™ FA 96 RV assay was evaluated using nasopharyngeal swab samples. Methods Nasopharyngeal swab samples, totaling 859 samples, are collected according to the procedures by the clinical institution in France and preserved in Virus transport media. Once anonymized and randomly allocated, the swab transport media tube, without capping procedure, are directly placed onto the ExiStation™ FA 96. Subsequently, both extraction and real-time RT-PCR are automatically processed. Clinical sensitivity, specificity, and agreement are analyzed by comparing results with confirmatory reagents SARS-CoV-2 RT-qPCR Reagent Kit, PKAmp™ Respiratory SARS-CoV-2 RT-PCR Panel Kit, and Bosphore SARS-CoV-2/Flu/RSV Panel Kit, as well as comparator reagent Allplex™ Respiratory Panel 1 and Allplex™ SARS-CoV-2 Assay. Results The comparison between confirmatory reagents and the ExiStation™ FA 96 RV resulted in a clinical sensitivity of at least 96.4% (164/164 for SARS-CoV-2, 64/65 for Influenza A, 74/75 for Influenza B, and 53/55 for RSV) and a clinical specificity of 100% (500/500 for all targets). When compared with the comparator reagent, the overall agreement and Cohen's kappa value were both determined to be above 99.1% and 0.989, respectively (664/664 for SARS-CoV-2, 564/565 for Influenza A, 573/575 for Influenza B, and 550/555 for RSV). Additionally, any discrepant samples identified in comparison with the comparator reagent were verified through sequencing analysis. Upon sequencing analysis on a total of 8 samples and aligning the confirmed results with the analysis content, no alterations observed in the analysis of clinical sensitivity and specificity. Conclusions The evaluation of the ExiStation™ FA 96 RV assay showed outstanding clinical performance in detecting four respiratory viruses, SARS-CoV-2, Influenza A, Influenza B, and RSV, with high sensitivity and specificity. This study supports that the ExiStation™ FA 96 RV assay is a reliable tool for simultaneous molecular diagnostics of various respiratory infections in clinical laboratories.