Independent Clinical Laboratories Research Articles

A French multicenter analytical evaluation of the automated Lumipulse G sNfL blood assay (Fujirebio®) and its comparison to four other immunoassays for serum neurofilament light chain assessment in clinical settings

ObjectivesMeasurement of serum neurofilament light chain (sNfL) protein is becoming a key biomarker for many neurological diseases. Several immunoassays have been developed to meet these clinical needs, revealing significant differences in terms of variability and results. Here, we propose a French multicenter comparison of 5 sNfL assays. Methods6 replicates of 3 pools with low (10 pg/mL), medium (30 pg/mL) and high (100 pg/mL) sNfL values and one replicate of 12 samples with growing sNfL values were analyzed by six independent French clinical laboratories. The analytical performances of the sNfL blood assay (Fujirebio®) on Lumipulse G were first evaluated then compared to four other immunoassays: NF-light V2 (Quanterix®) on SiMOA HD-X, Human NF-L (Biotechne®) on Ella, R-Plex Human Neurofilament L (MSD®) on Sector 2400; manual ELISA test using Uman Diagnostic/Quanterix®. ResultsInter-center comparison of the Lumipulse blood assay revealed limited but significant differences in the mean sNfL values across low, medium, and high pools between each city (p < 0.001) and between the two different batches used. Coefficients of variation of pools ranged from 2.0 to 16.9 %. Z-score of sNfL results of the 12 samples ranged from −1.70 to +1.71. Inter-technique comparison showed a systematic difference of sNfL values, with a overestimation of MSD and Ella over other tests. Nonetheless, results were all significantly correlated (p < 0.001). ConclusionThe automated Lumipulse assay produced comparable sNfL values across laboratories; but further adjustments are needed to harmonize sNfL results. Biologists and physicians should be aware of the variability in results between different immunoassay suppliers.

The experience and reflections of GC labs as an independent clinical laboratory to the COVID-19 pandemic in South Korea

BackgroundAmid the COVID-19 pandemic, extensive testing was undertaken by independent clinical laboratories (ICLs), yet limited research exists on this matter. Drawing from Green Cross Laboratories (GC Labs)' pandemic response experience, this study seeks to offer insights for preparation for the next pandemic.MethodsThis retrospective study analyzed the outcomes of SARS-CoV-2 real-time reverse transcription polymerase chain reaction (SARS-CoV-2 rRT PCR) tests administered by GC Labs for COVID-19 diagnosis, upon request by different organizations, between February 2020 and April 2022. The distribution of institutions that requested the tests, the type of tests, and the positive rate were analyzed. We investigated resource allocation details.ResultsICLs were responsible for conducting 85.6% of all tests carried out under South Korea’s COVID-19 testing policy during the pandemic. The availability of free testing regardless of symptoms led to a significant increase in the use of pooled tests, which accounted for more than 80% of all tests conducted after August 2021. The gender and age distribution of COVID-19 cases nationwide and GC Labs’ positive cases were similar. When we analyzed the positive rate by requesting organizations during the COVID-19 pandemic, despite an overall nationwide positivity rate of 35%, high-risk facilities exhibited a positivity rate of less than 5% by maintaining preemptive testing. The most notable increase in resources during the pandemic was seen in human resource input.ConclusionsSouth Korea's ICLs were able to conduct large volumes of testing during the COVID-19 pandemic because of their logistics and computer systems, scalable testing space, and trained testing personnel. They also had the flexibility to bring in additional resources to expand testing capacity because they are specialized testing organizations. Hence, ICLs could execute the pooled test that the government had introduced for extensive general population screening. The preemptive periodic testing of high-risk populations kept the positive rate much lower than in the general population. This study's findings will aid in refining mass testing-based policies for the next pandemic.

Matrix-matched calibrators are necessary for robust and high-quality dried blood spots lead screening assays by inductively coupled plasma-mass spectrometry

Background and aimsReliable lead screening methods are necessary to support early identification of lead exposure in children. Sample collection using dried blood spots (DBS) offers advantages compared to traditional venipuncture and capillary collection. Here, we describe and compare three lead DBS inductively coupled plasma-mass spectrometry (ICP-MS) methods for lead screening. Materials and methodsLead was extracted from Whatman 903 protein saver cards punches and analyzed by ICP-MS across three independent clinical laboratories. Each laboratory evaluated the performance of aqueous and matrix-matched DBS calibrators using external quality control samples (WI State of Laboratory of Hygiene Program). Leftover patient samples (n = 39) were used for an interlaboratory comparison of lead DBS. Lead DBS results were compared to whole blood methods. ResultsThe DBS ICP-MS methods using matrix-matched DBS calibrators had superior performance to the aqueous calibrations. There was a strong correlation between lead measured in DBS (matrix-matched) and whole blood for the three methods evaluated. ConclusionLead can be measured accurately by ICP-MS in DBS samples when matrix-matched calibrators are used. External quality control programs are valuable to assess the performance of DBS methods. DBS lead ICP-MS methods are a robust analytical option for lead screening even though the limitations of DBS are well recognized.

Management Practice of Outsourcing Hospital Tests to Independent Clinical Laboratories

With the development of medical technology and the deepening of medical reform, hospital laboratory test continues to expand. Affected by factors such as technology and cost, the business of outsourcing laboratory test to independent clinical laboratories develops rapidly. However, this cooperation mode has not been carried out for a long time and lacks systematic management experience. Through the analysis of the motivation of hospital delivery, this study expounds the classification, judgment basis and requirements for suppliers of third-party clinical laboratory delivery, as well as the operation practice of laboratory test delivery, so as to provide reference for more standardized and effective testing delivery for hospitals.

Detection of Borrelia burgdorferi sensu lato DNA in cerebrospinal fluid samples following pre-enrichment culture

Molecular methods for diagnosing Lyme neuroborreliosis (LNB) have shown suboptimal diagnostic sensitivities. The objective of this study was to improve the clinical sensitivity of PCR detection of Borrelia burgdorferi sensu lato spirochetes by inoculating cerebrospinal fluid (CSF) from patients suspected of LNB directly into culture medium at the time of lumbar puncture, with this pursuing enrichment of Borrelia spirochetes before PCR analysis. Adult patients with symptoms suggestive of LNB were prospectively enrolled at two hospitals in the Region of Southern Denmark. The CSF-culture samples were incubated for at least eight weeks. During this period, culture sample aliquots were analysed for the presence of Borrelia DNA by separate PCR protocols in two independent clinical laboratories. The included patients were diagnosed with definite (n=12) or possible (n=2) LNB, and non-LNB (n=171) based on clinical and paraclinical findings. Patients in the LNB and the non-LNB group had a median duration from symptom onset to lumbar puncture of 40 days (IQR [23–90] days) and 120 days (IQR [32–365] days), respectively. Pre-enrichment growth of Borrelia spirochetes was accomplished from three patients (21 %) in the LNB group. The positive culture samples were confirmed by both the digital droplet PCR and the real-time PCR methods employed. All CSF samples were PCR negative in the non-LNB group. The results of this study do not support the use of Borrelia-specific PCR as a general routine diagnostic tool in adults. Still, they suggest it may prove of additional value in selected patients with a limited time from symptom onset to sample collection.

Analysis of D- and L- Isomers of (Meth)amphetamine in Human K2EDTA Plasma

Methamphetamine and its metabolite amphetamine are frequently abused drugs. Whether obtained legally or from clandestine laboratories it is of relevance to determine the chiral makeup of these drugs for investigative purpose. Although urine and oral fluid matrices are commonly offered, less available to independent laboratories are techniques to verify dextro (D-) or levo (L-) (meth)amphetamine from human K2EDTA plasma. This paper outlines the development and validation of a method that includes the addition of internal standard and a two-step liquid-liquid extraction to remove the analytes from human K2EDTA plasma by triple quadrupole mass spectrometry (LC-MS/MS). The assay was validated according to the United States Food and Drug Administration and College of American Pathologists guidelines, including assessment of the following parameters in plasma validation samples: linear range, limit of detection, lower limit of quantitation, matrix effects, inter- and intra-day assay precision and accuracy, carry over, linearity of dilution, matrix effects and stability. The outcome is a validated and reliable method for the determination of D- and L- isomer concentration of meth(amphetamine) human plasma samples that can be easily adopted by independent clinical laboratories.

Positive predictive values and outcomes for uninformative cell-free DNA tests: An Italian multicentric Cytogenetic and cytogenomic Audit of diagnOstic testing (ICARO study).

To establish the positive predictive values (PPV) of cfDNA testing based on data from a nationwide survey of independent clinical cytogenetics laboratories. Prenatal diagnostic test results obtained by Italian laboratories between 2013 and March 2020 were compiled for women with positive non-invasive prenatal tests (NIPT), without an NIPT result, and cases where there was sex discordancy between the NIPT and ultrasound. PPV and other summary data were reviewed. Diagnostic test results were collected for 1327 women with a positive NIPT. The highest PPVs were for Trisomy (T) 21 (624/671, 93%) and XYY (26/27, 96.3%), while rare autosomal trisomies (9/47, 19.1%) and recurrent microdeletions (8/55, 14.5%) had the lowest PPVs. PPVs for T21, T18, and T13 were significantly higher when diagnostic confirmation was carried out on chorionic villi (97.5%) compared to amniotic fluid (89.5%) (p<0.001). In 19/139 (13.9%), of no result cases, a cytogenetic abnormality was detected. Follow-up genetic testing provided explanations for 3/6 cases with a fetal sex discordancy between NIPT and ultrasound. NIPT PPVs differ across the conditions screened and the tissues studied in diagnostic testing. This variability, issues associated with fetal sex discordancy, and no results, illustrate the importance of pre- and post-test counselling.

579P A multicenter evaluation of a low pass whole genome sequencing-based solution for homologous recombination deficiency detection

Poly (ADP-ribose) polymerase inhibitors (PARPi) induce synthetic lethality in homologous recombination deficient (HRD) tumors and have revolutionized ovarian cancer treatment. Patient stratification methods currently used are based on genome-wide enumeration of known HRD biomarkers and require deep sequence profiles (> 30x), in some cases from tumor-normal pairs. The cost and challenges introduced by implementing the current solutions hinder the clinical adoption of HRD testing. Here we present a multicenter performance evaluation study of an alternative deep learning-based decentralized solution for HRD detection, the SOPHiA DDM Dx HRD Solution (SOPHiA GENETICS SA), which leverages the impact of HRD on the coverage profiles obtained from low-pass whole-genome sequencing (lpWGS) data (X1 fold coverage). We generated and sequenced, in 5 independent clinical laboratories, 153 low pass WGS libraries (X1, ∼10 million reads, Illumina) for 150 Formalin-Fixed Paraffin-Embedded ovarian cancer samples. HRD classification was performed according to the manufacturer’s recommendations. The analytical performance was evaluated as overall (OPA), positive (PPA), and negative (NPA) percentage of agreement with Myriad myChoice CDx status (Myriad Genetic Laboratories, Inc.; US FDA-approved). The Quality Control criteria for SOPHiA DDM Dx HRD Solution analysis were met for 97,3% of the libraries (n=149). We found a high overall percentage agreement, 93.7% (97.1% NPA and 90.4% PPA) between SOPHiA DDM Dx HRD Solution and Myriad myChoice CDx classification (Table). Additionally, SOPHiA DDM Dx HRD Solution results for samples analyzed in duplicate were 100% reproducible.Table: 579PConfusion matrix of comparison between Myriad myChoice CDx and SOPHiA DDM Dx HRD Solution results (149 unique samples)SOPHiA DDM Dx HRD SolutionPositiveNegativeFailMyriad myChoice CDxPositive669-Negative2673Fail-11 Open table in a new tab We conclude that SOPHiA DDM Dx HRD Solution supports accurate HRD detection from low pass whole genome sequencing data, which is amongst the most cost-effective and easy to implement genome profiling methods.

A deep learning solution for detection of homologous recombination deficiency in ovarian cancer using low pass whole-genome sequencing: Evaluation of the analytical performance.

e17599 Background: Poly (ADP-ribose) polymerase inhibitors (PARPi) induce synthetic lethality in cells with homologous recombination deficiency (HRD). PARPi treatment revolutionized management of patients with cancer, particularly in types where HRD is common, such as ovarian and breast cancer. However, challenges in the implementation of available methods currently limit adoption of HRD testing in the clinics. Here we present the analytical performance evaluation of the Genomic Integrity Index (GII) (SOPHiA GENETICs SA). Methods: GII is a deep-learning based solution for identification of HRD positive tumors from low-pass whole genome sequencing (lpWGS) data (X1 fold coverage). The analytical performance of the GII was evaluated as positive (PPA), negative (NPA) and overall (OPA) percentage of agreement with the HRD status determined by Myriad myChoice CDx (Myriad Genetic Laboratories, Inc.; US FDA-approved). We generated whole genome sequencing libraries for DNA extracted from 139 ovarian cancer Formalin-Fixed Paraffin- Embedded samples, in 4 independent clinical laboratories. We sequenced to the equivalent of 1X coverage (̃10 million reads, 150 base paired end reads, Illumina) and performed HRD classification data using GII using manufacturer’s recommended thresholds. Results: The GII demonstrated high analytical concordance with Myriad myChoice CDx with 91.7% PPA, 95.5% NPA and 94.5% OPA (Table). The HRD status obtained by GII from a subset of positive and negative samples was 100% reproducible (n = 4) between runs. Conclusions: The HRD status obtained by GII is highly concordant with that obtained from standard method, supporting that GII allows accurate and reproducible detection of HRD from lpWGS data. LpWGS is amongst the most cost-effective and easy to implement genome profiling methods, making it uniquely suited for clinical applications. [Table: see text]

Pivotal Study Evaluating the Safety and Effectiveness of the Abre Venous Self-Expanding Stent System in Patients With Symptomatic Iliofemoral Venous Outflow Obstruction.

Iliofemoral venous obstruction is recognized with increasing frequency as the underlying cause of lower extremity symptoms including edema, pain, skin changes, and, in advanced cases, ulceration. This study sought to evaluate the safety and effectiveness of the Abre venous self-expanding stent system for the treatment of symptomatic iliofemoral venous outflow obstruction. The ABRE Study (A Multi-Center, Non-Randomized Study to Evaluate the Safety and Effectiveness of the Abre Venous Self-Expanding Stent System in Patients With Symptomatic Iliofemoral Venous Outflow Obstruction) is a single-arm, multicenter, prospective study that included 200 subjects from 24 global sites. The primary end points were 12-month primary patency and major adverse events within 30 days. Secondary end points included lesion and procedure success, primary-assisted and secondary patency, major adverse events, stent migration, stent fracture, and quality of life changes. End point-related adverse events and imaging studies were adjudicated by independent clinical events committee and core laboratories, respectively. Venous obstruction cause was classified as acute deep vein thrombosis (16.5%, 33/200), post-thrombotic syndrome (47.5%, 95/200), or nonthrombotic iliac vein lesion (36.0%, 72/200). The common iliac and external iliac veins were stented in 96.0% (192/200), 80.5% (161/200) of subjects, respectively. Stent implant into the common femoral vein was required in 44.0% (88/200). Primary patency at 12 months was 88.0% (162/184). Four (2.0%) major adverse events occurred within 30 days. Twelve-month primary-assisted and secondary patency were 91.8% (169/184) and 92.9% (171/184), respectively. No stent fractures or migrations were reported. Mean target limb Villalta score decreased from 11.2±5.6 at baseline to 4.1±4.8 at 12 months, and the mean target limb revised Venous Clinical Severity Score decreased from 8.8±4.7 at baseline to 4.3±3.6 at 12 months. Clinically meaningful improvements in quality of life and venous functional assessment scores from baseline were demonstrated through 12 months in all measures. Symptomatic iliofemoral venous obstruction can be successfully treated with an Abre venous stent. Study outcomes demonstrated a high patency rate with a good safety profile. Patients demonstrated a significant reduction in clinical symptoms and improvement in quality of life that was maintained through 12-month follow-up. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03038438.

Changes in Seasonal Respiratory Illnesses in the United States During the Coronavirus Disease 2019 (COVID-19) Pandemic

BackgroundRespiratory tract infections are common, often seasonal, and caused by multiple pathogens. We assessed whether seasonal respiratory illness patterns changed during the COVID-19 pandemic.MethodsWe categorized emergency department (ED) visits reported to the National Syndromic Surveillance Program according to chief complaints and diagnosis codes, excluding visits with diagnosed SARS-CoV-2 infections. For each week during March 1, 2020 through December 26, 2020 (“pandemic period”), we compared the proportion of ED visits in each respiratory category with the proportion of visits in that category during the corresponding weeks of 2017–2019 (“pre-pandemic period”). We analyzed positivity of respiratory viral tests from two independent clinical laboratories.ResultsDuring March 2020, cough, shortness of breath, and influenza-like illness accounted for twice as many ED visits compared with the pre-pandemic period. During the last four months of 2020, all respiratory conditions, except shortness of breath, accounted for a smaller proportion of ED visits than during the pre-pandemic period. Percent positivity for influenza virus, respiratory syncytial virus, human parainfluenza virus, adenoviruses, and human metapneumovirus were lower in 2020 than 2019. Although test volume decreased, percent positivity was higher for rhinovirus/enterovirus during the final weeks of 2020 compared with 2019; with ED visits similar to the pre-pandemic period.DiscussionBroad reductions in respiratory test positivity and respiratory emergency department visits (excluding COVID-19) occurred during 2020. Interventions for mitigating spread of SARS-CoV-2 likely also reduced transmission of other pathogens. Timely surveillance is needed to understand community health threats, particularly when current trends deviate from seasonal norms.

Surveillance of Coronavirus Disease 2019 (COVID-19) Testing in Clinical Laboratories in Korea

In response to the ongoing coronavirus disease 2019 (COVID-19) pandemic, an online laboratory surveillance system was established to monitor severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time reverse transcription-PCR (rRT-PCR) testing capacities and results. SARS-CoV-2 rRT-PCR testing data were collected from 97 clinical laboratories, including 84 medical institutions and 13 independent clinical laboratories in Korea. We assessed the testing capacities to utilize SARS-CoV-2 rRT-PCR based on surveillance data obtained from February 7th to June 4th, 2020 and evaluated positive result characteristics according to the reagents used and sample types. A total of 1,890,319 SARS-CoV-2 rRT-PCR testing were performed, 2.3% of which were positive. Strong correlations were observed between the envelope (E) gene and RNA-dependent RNA polymerase (RdRp)/nucleocapsid (N) genes threshold cycle (Ct) values for each reagent. No statistically significant differences in gene Ct values were observed between the paired upper and lower respiratory tract samples, except in the N gene for nasopharyngeal swab and sputum samples. Our study showed that clinical laboratories in Korea have rapidly expanded their testing capacities in response to the COVID-19 outbreak, with a peak daily capacity of 34,193 tests. Rapid expansion in testing capacity is a critical component of the national response to the ongoing pandemic.

Multicenter clinical comparative evaluation of Alinity m HIV-1 assay performance.

Accurate, rapid detection of HIV-1 RNA is critical for early diagnosis, treatment decision making, and long-term management of HIV-1 infection. We evaluated the diagnostic performance of the Alinity m HIV-1 assay, which uses a dual target/dual probe design against highly conserved target regions of the HIV-1 genome and is run on the fully automated Alinity m platform. This was an international, multisite study that compared the diagnostic performance of the Alinity m HIV-1 assay to four commercially available HIV-1 assays routinely used in nine independent clinical laboratories. Alinity m HIV-1 assay precision, detectability, and reproducibility was compared across four study sites. The Alinity m HIV-1 assay produced comparable results to currently available HIV-1 assays (correlation coefficient >0.995), with an overall bias of -0.1 to 0.10 Log10 copies/mL. The Alinity m HIV-1 assay and its predecessor m2000 HIV-1 assay demonstrated comparable detection of 16 different HIV-1 subtypes (R2 = 0.956). A high level of agreement (>88 %) between all HIV-1 assays was seen near clinical decision points of 1.7 Log10 copies/mL (50 copies/mL) and 2.0 Log10 copies/mL (200 copies/mL). Alinity m HIV-1 assay precision was 0.08 and 0.21 Log10 copies/mL at VLs of 1000 and 50 copies/mL, respectively, with a high level of detectability (≥97 % hit rate) and reproducibility across sites. The Alinity m HIV-1 assay provides comparable diagnostic accuracy to current HIV-1 assays, and when run on the Alinity m system, has the capacity to shorten the time between diagnosis and treatment.

Myocardial Infarction Can Be Safely Excluded by High-sensitivity Troponin I Testing 3 Hours After Emergency Department Presentation.

BackgroundThe accuracy and speed by which acute myocardial infarction (AMI) is excluded are an important determinant of emergency department (ED) length of stay and resource utilization. While high‐sensitivity troponin I (hsTnI) >99th percentile (upper reference level [URL]) represents a “rule‐in” cutpoint, our purpose was to evaluate the ability of the Beckman Coulter hsTnI assay, using various level‐of‐quantification (LoQ) cutpoints, to rule out AMI within 3 hours of ED presentation in suspected acute coronary syndrome (ACS) patients.MethodsThis multicenter evaluation enrolled adults with >5 minutes of ACS symptoms and an electrocardiogram obtained per standard care. Exclusions were ST‐segment elevation or chronic hemodialysis. After informed consent was obtained, blood samples were collected in heparin at ED admission (baseline), ≥1 to 3, ≥3 to 6, and ≥6 to 9 hours postadmission. Samples were processed and stored at –20°C within 1 hour and were tested at three independent clinical laboratories on an immunoassay system (DxI 800, Beckman Coulter). Analytic cutpoints were the URL of 17.9 ng/L and two LoQ cutpoints, defined as the 10 and 20% coefficient of variation (5.6 and 2.3 ng/L, respectively). A criterion standard MI diagnosis was adjudicated by an independent endpoint committee, blinded to hsTnI, and using the universal definition of MI.ResultsOf 1,049 patients meeting the entry criteria, and with baseline and 1‐ to 3‐hour hsTnI results, 117 (11.2%) had an adjudicated final diagnosis of AMI. AMI patients were typically older, with more cardiovascular risk factors. Median (IQR) presentation time was 4 (1.6–16.0) hours after symptom onset, although AMI patients presented ~0.5 hour earlier than non‐AMI. Enrollment and first blood draw occurred at a mean of ~1 hour after arrival. To evaluate the assay's rule‐out performance, patients with any hsTnI > URL were considered high risk and were excluded. The remaining population (n = 829) was divided into four LoQ relative categories: both hsTnI < LoQ (Lo‐Lo cohort); first hsTnI < LoQ and 2nd > LoQ (Lo‐Hi cohort); first > LoQ and second < LoQ (Hi‐Lo cohort); or both > LoQ (Hi‐Hi cohort). In patients with any hsTnI result <20% CV LoQ (Groups 1–3), n = 231 (23.9% ruled out), AMI negative predictive value (NPV) was 100% (95% confidence interval [CI] = 98.9% to 100%). In patients with any hsTnI below the 10% LoQ, n = 611 (58% rule out), AMI NPV was 100% (95% CI = 99.5% to 100%). Of the Hi‐Hi cohort (i.e., no hsTnI below the 10% LoQ, but both < URL), there were four AMI patients, NPV was 98.2% (95% CI = 95.4% to 99.3%), and sensitivity was 96.6.ConclusionsPatients presenting >3 hours after the onset of suspected ACS symptoms, with at least two Beckman Coulter Access hsTnI < URL and at least one of which is below either the 10 or the 20% LoQ, had a 100% NPV for AMI. Two hsTnI values 1 to 3 hours apart with both < URL, but also >LoQ had inadequate sensitivity and NPV.

Transforming Laboratory Utilization Review into Laboratory Stewardship: Guidelines by the PLUGS National Committee for Laboratory Stewardship.

Appropriate utilization of clinical laboratory services is important for patient care and requires institutional stewardship. Clinical laboratory stewardship programs are dedicated to improving the ordering, retrieval, and interpretation of appropriate laboratory tests. In addition, these programs focus on developing, maintaining, and improving systems to provide proper financial coverage for medically necessary testing. Overall, clinical laboratory stewardship programs help clinicians improve the quality of patient care while reducing costs to patients, hospitals, and health systems. This document, which was created by a new multiinstitutional committee interested in promoting and formalizing laboratory stewardship, summarizes core elements of successful hospital-based clinical laboratory stewardship programs. The core elements will also be helpful for independent commercial clinical laboratories.

Prospective prediction of resistance to neoadjuvant therapy in patients with locoregional esophageal adenocarcinoma

Prospective prediction of resistance to neoadjuvant therapy in patients with locoregional esophageal adenocarcinoma Daniel G Rosen,1 Weiwei Shan,2 Natalie Lassen,2 Clare Johnson,2 Kristen Oelschlager,2 Yaeli Bierman-Harrar,1 Kenneth A Kesler,3 Derek Maetzold,2 Sunil Badve,3 Robert W Cook,2 Romil Saxena3 1Baylor College of Medicine, Houston TX, USA; 2Castle Biosciences, Incorporated, Friendswood, TX, USA; 3Indiana University, Indianapolis, IN, USA Background: To clinically validate a multianalyte algorithmic immunohistochemistry (IHC) assay that has been previously shown to accurately identify patients with locoregional esophageal adenocarcinoma (EC) who will exhibit extreme resistance to neoadjuvant chemoradiotherapy. Methods: Archived biopsy specimens of EC were subject to IHC examination of compartmentalized immunoreactivity of nuclear factor kappa B (NF-&kappa;B), Sonic Hedgehog (SHH), and GLI family zinc finger 1 (Gli-1), and a labeling index score was assigned to each biomarker. Test prediction was generated by logistic regression predictive modeling, using the labeling index scores for all three analytes from each sample, referring to a validated training set of 167 EC patients. Accuracy of the test was determined by comparing the predicted outcomes with pathologically determined College of American Pathologists tumor response grade. Analytical validity of the test was measured by comparing validation set prediction results obtained in two independent Clinical Laboratory Improvement Amendment-certified laboratories, and by measuring concordance between two trained labeling index readers. Results: Specimens from 64 patients that met specific criteria were collected. No technical failure was encountered during the IHC labeling procedures. The logistic regression algorithm generated an area under the curve of 0.96 and 0.85 for the 64 sample cohort in two independent clinical laboratories, respectively, comparing predictive results with the established training set. Positive predictive values of 88% and 82% were also achieved in each laboratory, respectively. A negative predictive value of 83% was reported by both laboratories. Interobserver concordance was 97%. Discussion: We report the second validation of a multianalyte algorithmic IHC-based predictive test that accurately identifies EC patient response to fluorouracil-based neoadjuvant chemoradiotherapy regimens under College of American Pathologists-accredited Clinical Laboratory Improvement Amendment-certified laboratory protocols. The validated assay provides the opportunity to identify patients with EC who have extreme resistance to neoadjuvant chemoradiotherapy who are resistant to fluorouracil-based neoadjuvant chemoradiotherapy, allowing for more effective treatment planning by clinicians and less toxicity for patients. Keywords: neoadjuvant chemoradiation, immunohistochemistry, predictive test, validation

Evaluation of a next generation direct whole blood enzymatic assay for hemoglobin A1c on the ARCHITECT c8000 chemistry system.

The utility of HbA1c for the diagnosis of type 2 diabetes requires an accurate, precise and robust test measurement system. Currently, immunoassay and HPLC are the most popular methods for HbA1c quantification, noting however the limitations associated with some platforms, such as imprecision or interference from common hemoglobin variants. Abbott Diagnostics has introduced a fully automated direct enzymatic method for the quantification of HbA1c from whole blood on the ARCHITECT chemistry system. Here we completed a method evaluation of the ARCHITECT HbA1c enzymatic assay for imprecision, accuracy, method comparison, interference from hemoglobin variants and specimen stability. This was completed at three independent clinical laboratories in North America and Europe. The total imprecision ranged from 0.5% to 2.2% CV with low and high level control materials. Around the diagnostic cut-off of 48 mmol/mol, the total imprecision was 0.6% CV. Mean bias using reference samples from IFCC and CAP ranged from -1.1 to 1.0 mmol/mol. The enzymatic assay also showed excellent agreement with HPLC methods, with slopes of 1.01 and correlation coefficients ranging from 0.984 to 0.996 compared to Menarini Adams HA-8160, Bio-Rad Variant II and Variant II Turbo instruments. Finally, no significant effect was observed for erythrocyte sedimentation or interference from common hemoglobin variants in patient samples containing heterozygous HbS, HbC, HbD, HbE, and up to 10% HbF. The ARCHITECT enzymatic assay for HbA1c is a robust and fully automated method that meets the performance requirements to support the diagnosis of type 2 diabetes.

129-P: DEVELOPMENT OF THE FIRST FDA 510(K) CLEARED DNA SEQUENCING SYSTEM

To provide an IVD cleared HLA sequence based typing system Life Technologies developed a 510(k) system submission including the 3500 Dx Genetic Analyzer, 3500 Dx Data Collection Software, the Veriti™ Dx Thermal Cycler, SeCore® HLA SBT kits, and uTYPE® Dx HLA SBT Analysis Software (SeCore system). Two external clinical studies were performed to demonstrate SeCore® system accuracy and reproducibility. The first clinical trial focused on HLA typing concordance across 3 independent clinical laboratories. The sites selected 300 samples for comparison of the SeCore® system results to the predicate device SSP Unitray® Direct to High Res. The second external study evaluated system reproducibility, where 3 laboratories ran the same “known” samples. The samples were run 6 times over 6 non-consecutive days by 2 operators with each SeCore® kit. For the comparative study, the concordance rate was calculated and the corresponding exact two-sided 90% confidence interval was calculated by the Clopper-Pearson method for each kit. The lower confidence limit was greater than 0.95 for all kits for study success. Actual concordance was >97% for all kits. Each clinical site identified at least 1 potential novel allele in their sample set. Out of 299 samples tested, 11 were discordant to the predicate device. New alleles were identified in HLA-B, -C, -DRB4, and HLA-DPB1. The reproducibility study concordance rate was calculated using the same method as described in the comparative study. The actual concordance rate was 100% for all sites with no instances of discordance. The study also demonstrated reproducibility of uTYPE® Dx software allele pairs within the results list and recommended group specific sequencing primers (GSSPs). The results for the SeCore® system met the acceptance criteria of at least 95% concordance with 90% confidence for all Class I and Class II loci and GSSPs demonstrating system accuracy and reproducibility. Agostini: Life Technologies: Employee. Shi: Life Technologies: Employee. Kashi: Life Technologies: Other: Study Site Participant. Noreen: Life Technologies: Other: Study Site Participant. Davidson: Life Technologies: Other: Study Site Participant. Tambur: Life Technologies: Other: Study Site Participant. Williams: Life Technologies: Other: Study Site Participant. Wu: Life Technologies: Other: Study Site Participant. Dinauer: Life Technologies: Employee.

A nationwide investigation and analysis of present status of independent clinical laboratories in China and suggestions

Objective To have a general picture the history and existing problems of independent clinical labs in China, for the purpose of building a supervision mechanism for such novel clinical institutions-clinical labs. Methods By way of the nationwide network of clinical labs, ICLs in China were surveyed with written questionnaires and field check. Results ICLs have grown into a greater and diversified scale thanks to the development of China's economy and laboratory technology. However,such vulnerabilities as unbalanced staff ratio, full-range quality control bugs, cutthroat competition,asymmetrical information disclosure, and bio-safety have loomed large in the meantime. Conclsion It is time to formulate a stricter industry access system and appropriate regulatory modes; ICLs should take a good care of the Four relations in their development, and health regulators should play a tighter role in the Four supervisions. All these aim at better sharing medical resources, and building a win-win environment for the people, hospitals and ICLs. Key words: Independent clinical laboratory; Quality management; Supervision pattern

Effects of Clinical Laboratory Choice on Study Outcome: An Interlaboratory Evaluation of Aminotransferase Levels

To determine if laboratories with disparate alanine aminotransferase (ALT) reference ranges would report different rates of elevation greater than the upper limit of reference range (ULRR) and thus have the potential to alter study results. Interlaboratory evaluation. Research department of a poison and drug center. Sixty-five serum samples collected from a previously published randomized clinical trial that were stored at -57 degrees C for approximately 2 years. Stored serum samples were divided and sent to two independent clinical laboratories (laboratory A and laboratory B) that had disparate ALT reference ranges. Samples were stratified by ALT levels measured during the primary study to provide a spectrum of ALT values. The ULRR for serum ALT level at laboratory A was 63 and 54 U/L for male and female subjects, respectively, and for laboratory B was 31 U/L for both male and female subjects. Each laboratory used different instruments and reagents. The primary outcome was the rate of ALT elevation (> 1 x ULRR and > 3 x ULRR) for each study laboratory. The overall mean ALT activity at laboratory A was 33.6 U/L (95% confidence interval [CI] 28.1-39.2 U/L) and at laboratory B was 47.92 U/L (95% CI 40.0-55.8 U/L). Although laboratory A had the higher ULRR (74% higher for female subjects, 103% higher for male subjects), it consistently reported lower ALT values. Laboratory B reported a significantly higher proportion of samples that had an ALT value greater than 1 time the ULRR and greater than 3 times the ULRR. Our findings suggest that laboratories systemically report different values for aminotransferase levels and that the choice of laboratory may alter the proportion of patients who have an elevation in ALT levels. Until standardized reference ranges are adopted, studies reporting an outcome that depends on the reference range (such as "abnormal" or > 3 x ULRR) will be subject to misclassification bias based on the laboratory performing the analysis.