Clinical Chemistry Research Articles

B-324 Pilot Study Result of EQA for Fecal Immunochemical Test for Hemoglobin Using a Novel Ready-to-Use Sample Material

Abstract Background The primary screening method for colorectal cancer is fecal immunochemical test (FIT) detecting human hemoglobin (Hb) in feces. There are several tests on the market both for automated analyzers and point-of-care testing (POCT). To ensure high quality results, the tests should be monitored with appropriate quality assessment procedures including participation in external quality assessment (EQA) programs. By participating in an EQA program using a stool-like material, clinical laboratories and POCT sites can fulfil the ISO 15189 requirements of monitoring the complete laboratory process from pre- to postanalytical phases in addition to the quantitative analytical phase of FIT. Here we present the first results of an international EQA pilot study for quantitative FIT using a novel ready-to-use stool-like material, performed by EQA provider Labquality. Methods 40 participants from 8 countries using 9 different FIT reagents were recruited for the pilot study performed in 2023. A set of artificial stool samples containing human hemoglobin uniformly was shipped to the participants at ambient temperature. The sample material is developed by HECTEF (Health Care Technology Foundation, Japan). The participants were instructed to collect the sample with their test specific sample collection kit and perform analysis according to the manufacturer’s instructions as a regular patient sample. Quantitative results (µg Hb/g feces) and qualitative interpretations (positive/negative) were reported in Labquality’s electronic platform LabScala. The quantitative target value was a method group consensus mean. A questionnaire regarding the usability of the sample material was sent to all participants. Results Sample S001 contained no Hb and all participants (40/40) reported a result corresponding to the lower detection limit of their test in use or a low numeric result most likely explained by unspecific background. All reported a negative interpretation. Sample S002 was a high positive sample for Hb. The measured value exceeded the upper detection limit of 4/9 tests (Exdia iFOB, Precision Biosensor; Fecal Occult Blood (iFOB) Neo, Boditech; FOB Test, VedaLab; NADAL FOB Quant test, Nal von Minden). The mean values and CV% were 116 µg/g and 8% for iFOBT, Aidian; 192 ug/g and 4% for Standard iFOB FIA, SD Biosensor; 144 µg/g and 45% for FOB assay kit FOB Gold, Sentinel Diagnostics (different clinical chemistry analyzers used); 91 µg/g and 26% for OC-Sensor FIT, Eiken Chemical. All participants responded a positive qualitative clinical interpretation. The majority of the responders on the feedback questionnaire (26/35) found the samples to be easy to use including comments of the sample being user-friendly and ready-to-use, resembling a patient sample and easy to apply with the test specific sample collection kit. Conclusions The fecal-like sample used in this Labquality’s EQA pilot study evaluates the complete analytical process including the preanalytical, analytical and postanalytical phases. An EQA scheme using this sample material is more compliant to ISO 15189 requirements compared to schemes where liquid or lyophilized samples are used. The new sample material used on this pilot study was positively received by most of the participants and it was compatible with all tests included in the study.

A-096 A New Direct Bilirubin (DBIL) Assay with Enhanced Performance in Anti-hemolysis Interference on Mindray BS-2800M Analyzer

Abstract Background Serum bilirubin could be used to assess liver functions. Due to clinical importance, it is highly desired to have an accurate bilirubin test. However, there are circumstances where error could occur in bilirubin test results. In particular, the hemolysis interference is one of the major problems that could mislead the direct bilirubin results because of their relatively high occurring frequencies in the clinical laboratories. To resolve this issue and improve the accuracy for the direct bilirubin, we developed a new reagent formulation for DBIL assay that minimizes hemolysis interference. In addition, this reagent also shown good performance characteristics on Mindray BS-2800M Clinical Chemistry analyzer. Methods The new DBIL assay is a vanadate-oxidation method that bilirubin is gradually transformed to biliverdin because of oxidizing agent vanadate, resulting in decreasing of absorbance at 450 nm. Two-level calibration is used for this assay. DBIL concentrations are obtained from the calibration line with signals from the patient samples in the assay. Following CLSI protocols, basic assay performances were evaluated: interference, precision, linearity, method comparison and low end detection (LOB, LOD, LOQ). Results Hemolysis interference was tested in parallel with DBIL reagents from different IVD companies, Roche, Wako and Chinese domestic main-player companies, A, B, and C. The results showed that the reagents of A and B companies were significantly suffered from hemolysis interference with maximum bias exceeded -30%. Although there are some effects on the anti-hemolysis with DBIL reagents of Wako and C company, the DBIL reagent of Mindray was the best with less than -8% of impact when hemolysate hemoglobin was up to 1000 mg/dL (H index). The Diazo DBIL assay from Roche shown issue with hemolysis interference. The interference to our new DBIL assay from lipid (up to 1000 mg/dL) and ascorbic acid (up to 30 mg/dL) were also with less than ±10% impact. The precision study was run according to EP05A3 with two commercial controls (∼ 10 and 30 µmol/L) and three serum sample pools (∼ 6.8,17.1 and 342 µmol/L). The CVs of repeatability were ranged from 0.54% to 0.58% for controls and 0.24% to 0.88% for serum pools, respectively. The within-lab precision was below 2.5%. The analytical linearity was determined as from 0.66 µmol/L to 439.66 µmol/L. For low-end detection, the LOB, LOD and LOQ were 0.5,1.0 and 1.7 µmol/L, respectively. In addition, the Mindray (y) correlated well with the DBIL assay of Wako (x) reagent on Mindray BS-2800M system (y): y =0.9847 x+0.1301 (r =0.9997, n =400, sample range: 1.08 - 430.00 μmol/L). Conclusions The new Mindray direct bilirubin assay shown a good anti-hemolysis interference performance on BS-2800M system and demonstrated good performances in other assay characteristics. It is therefore suitable for use in clinical laboratories.

A-323 Advancing Point-of-Care Testing: Independent Evaluation of the Truvian Platform

Abstract Background To address the deficiencies of long turnaround time, increased cost and delayed medical intervention in the current paradigm of routine blood testing, Truvian has developed an automated blood testing platform that provides timely and lab-accurate results at the point of care. With 300 µL from a single Lithium Heparin blood sample, the Truvian solution generates 34 test results, including CMP, Lipid, HbA1c, TSH and CBC in under 30 minutes (TruWellness PanelTM).The present study focused on rigorous evaluation of the reliability and accuracy of Truvian's platform in a real-world clinical setting by untrained operators. Platform precision was measured over time on multiple Truvian instruments under standardized protocol. Accuracy and reliability were assessed independently at the UC San Diego Anti-Viral Research Center (AVRC) by testing samples from donors with chronic medical conditions and comparing against FDA cleared devices, Roche Cobas and Sysmex-XN. Methods Precision was assessed using the control workflow where three commercially available controls, were loaded as sample inputs into the Truvian consumables to perform the TruWellness Panel(TM). Three levels of controls were run in quadruplicate daily on 4 instruments (N > 100 per instrument). Within and between run, day, instrument, and consumable lot variance components were assessed.Accuracy was assessed as part of an IRB-approved method comparison study at AVRC by untrained operators. A total of 50 unique donors representing various disease states were consented and enrolled. Three 4-mL blood samples were collected from each donor: one Lithium Heparin (LiHep) sample for the Truvian System's TruWellness PanelTM, another LiHep gel tube for Roche Cobas clinical chemistry and TSH assays, and an EDTA sample for the Sysmex complete blood count with 3-part differential and HbA1c. All samples were tested on the Truvian System within an hour of collection or processed for central lab testing. Concordance to comparator devices was assessed via relative difference plots, Passing-Bablok and/or Deming regression analyses. Results Our results indicated that the performance of Truvian's instrument met pre-specified reliability, precision and accuracy criteria (per preliminary analysis of the first 50 patients). Reproducibility results showed 100% (69/69) of all tests met specifications. Interim analysis of the first 50 patients in the method comparison study indicates a robust concordance with predicate devices with 20 out of 23 tests showing a correlation coefficient of ≥ 0.9. During donor testing, the instrument demonstrated 96% (48/50) run reliability with only a single operator-induced error where the blood tube was not loaded correctly, highlighting the robustness and ease of use of the platform. Conclusions The present evaluation underscores Truvian's instrument as an easy-to-operate platform that can be run by untrained operators, maintain reliability in real-world clinical settings, and deliver accurate and precise results. Enrollment and sample testing are ongoing, with plans to expand the sample size to 200 donors and study completion planned for May 2024. Broadening the study to encompass a wider range of analyte measurements among chronic disease patients is expected to enhance performance data. This independent evaluation provided confidence in Truvian Platform’s performance and suitability for practical healthcare applications.

A-132 Next generation ammonia reagent with improved reagent composition and assay performance

Abstract Background Ammonia is produced by catabolism of protein and other compounds which contain nitrogen. Elevated ammonia levels are toxic for the central nervous system. High plasma ammonia is a prognostic factor for hepatic and kidney disease or inherited metabolic disorders in urea cycle metabolism. The reliable and accurate quantification of ammonia is influenced by assay, reagent, and sample management. Current commercially available GLDH enzyme-based ammonia assay reagents experience high bias between matched Lithium Heparin and K2-EDTA samples, poor accuracy, imprecision at the low end, large HIL (hemolysis, icterus and lipemia) interferences and shorter shelf life. To improve upon the listed deficiencies, we developed an improved GLDH based ammonia assay in a two-part format with improved reagent composition. Methods Ammonia reagent in 2-part format R1 and R2 were assessed for accuracy, precision, interference by HIL reportable range, sensitivity (LoB, LoD, LoQ), shelf life, matched matrix comparison (Lithium Heparin vs K2-EDTA) and method comparison. All testing were performed using Li Heparin plasma samples in Beckman DxC700AU analyzer. Accuracy was tested using Verichem ammonia standards which are ACS ammonia standard material. Twenty-day precision studies were performed using three levels of ammonia concentrations using Bio-Rad Liquichek Ammonia controls and plasma samples. Interference was tested in two ammonia concentrations (40-50 µmol/L) and (200-250 µmol/L) using commercially available spiking material for clinical chemistry assays such as conjugated and unconjugated bilirubin, Intralipid and in-house prepared hemolysate. Infinity Ammonia Reagent on Beckman Coulter AU Chemistry Analyzers was used for method comparison studies Results Next generation ammonia showed good accuracy with Verichem ammonia standards and acceptable within-run and total precision. Studies showed significant improvement in sensitivity and longer shelf life (>18 months). Next generation ammonia is less affected by interferences from icterus (100 mg/dL), lipemia (1000 mg/dL intralipid) and hemolysis (100 mg/dL). Comparison studies show no significant bias between match Lithium Heparin and K2-EDTA matched samples. Conclusions Next Generation Ammonia reagent showed very good overall performance required for reliable and accurate quantification of ammonia in human plasma sample.

B-221 Combined RT-PCR and Whole Exome Sequencing Pharmacogenetic Testing in Polypharmacy Patient: A Case Report

Abstract Background Pharmacogenetics has become one of the main branches of Precision Medicine owing to its usefulness for patients’s optimal therapeutic management. Notwithstanding, pharmacogenetic testing results must be taken carefully, specially in multimorbidity patients with a variety of drugs prescribed. The aim of the present work is to introduce a combined RT-PCR and Whole Exome Sequencing Approach for pharmacogenetic testing in a patient with multiple drug-related adverse events. Case Background A 67 years old female was derived to our Clinical Chemistry Unit for pharmacogenetic testing due to multiple drug-related adverse events: nifedipine-voriconazole interaction, voriconazole-related neurological toxicity and moxifloxacin-related dizziness. Aditionally, she had been receiving morphine, corticoid for her reumatoid arthritis and antituberculous therapy (r isoniazid / pyrazinamide / rifampin and ethambutol). Methods Patient’s DNA was extracted from a blood sample and undergone by pharmacogenetic testing in two parallel ways: -A first genotyping assay was carried out using Taqman® OpenArray™ PGx Express 120 panel (ThermoFisher™), according to manufacturer’s instructions. -Simultaneusly, in order to cover possible copy number variants and SNPs not covered by our RT-PCR array, a whole exome sequencing run was performed on IlluminaTM NextSeq 1000. Sample library was prepared applying a custom GRCh38 pipeline. Results Relevant variants related to patient’s therapy found by RT-PCR are shown in table 1. SNPs genotyped by RT-PCR were confirmed by NGS. Moreover, whole exome sequencing revealed a deletion in exon 5 of SLCO1B1 gene, which corresponds to SLCO1B1*49 (loss of function); and some variants in NAT2 that may cause toxicity in antituberculous treatment (diplotype NAT2*6C/*7C). Conclusions In those challenging cases that involve multimorbidity and polypharmacy patients, pharmacogenetic testing must be approached taking into account variants that are not covered by the analytical method routinely used and the possibility of complement it with alternative proccedures.

B-108 Delta Check Performance Assessment by Using Real-WorldData at the Temple University Health System​

Abstract Background Delta check is a post-analytic tool focusing on pre-analytical, analytical and post-analytical errors. It can be sensitive in detecting isolated errors affecting a single patient, as opposed to moving patient averages, which is another QC tool for detecting errors that affect a cohort/population of patients. As a computer-based system on selected tests, delta checks are to detect excessive changes from prior value in the patient test result and to detect possible specimen errors such as misidentified or compromised samples before results are reported. It may also play a role in detecting examination(analytical) issues and clinically significant results. If delta checks exceed established limits, the result is flagged. There is a common agreement that measurands with low indices of individuality (<0.6) make good candidates for the identification of cases of sample misidentification than higher indices of individuality (>1.4). CLSI EP33 Use of Delta Checks in the Medical Laboratory guidelines recommends that laboratories assess the validity of current delta check parameters by reviewing retrospective data on flagged results to determine if errors are being identified efficiently. At Temple University Health System, delta check limits were established historically by using published data, however, its performance characteristics have not been verified previously. Verification of clinical performance of predefined delta check limits can be performed either through mathematical calculations or via clinical audits. Clinical audits are achieved by documenting the follow-up actions and outcomes of the samples flagged by a delta check rule(s). It has been suggested that this should be performed using a protocolized follow-up procedure to ensure uniformity in the investigation and management. Corey M. et al. shared an excel template, a mathematical model that can be adopted easily by replacing the example data with retrospectively extracted data and modifying the parameters to suit their laboratory’s requirements. Methods We collected up to 30,000 data points for each 12 measurand in the clinical chemistry lab retrospectively. By using the excel template, clinical sensitivity and clinical specificity has been calculated. Furthermore, we created ROC curves and evaluated them using the (YI) Youden Index and AUC (Area Under the Curve). Results In general, YI values were found to be very low, less than 0.6. Highest YI was used to establish new delta check limits for each analyte; only the current creatinine delta check limit was found as effective, and no change required. 11 out of 12 measurand were required a revision of delta check limits and were proposed to replace with lower delta checks. AUC values were found between 0.56-0.794. Na showed the highest AUC, which correlates its low individuality index (0.5) and its effects on effectiveness of the delta check system. Conclusions It is of vital importance to establish a solid follow-up evaluation for delta check alerts and distinguish between integrity issues and clinically significant changes. Conclusively, this endeavor can develop into extensive information for the application, evaluation, and follow-up of delta checks whilst improving diagnostic accuracy and quality assurance.

A-118 Sigma Metric Performance of Chemistry Assays on 4 Instrument Systems

Abstract Background Chemistry panels play a crucial role in determining a person’s general health and well-being. These tests evaluate electrolyte balance and the status of several major organs. The Comprehensive Metabolic Panel (CMP) and Lipid Panel constitute approximately 87% of the blood tests prescribed in medical laboratories. Laboratories monitor assay performance by performing proficiency testing using quality controls (QC). College of American Pathologists (CAP) data is useful for laboratories to compare their proficiency testing performance to other laboratories and instrument systems. Sigma metrics serve as a valuable tool for laboratories to assess the quality and accuracy of their tests. Sigma scores vary from 0 to 6, with the 6 score designated as world-class performance, 5 as excellent, 4 as good, 3 as marginal, and 2 as poor. The analytical performance of 16 clinical assays from Abbott, Beckman, Roche, and Siemens instrument systems were compared using Sigma metrics. Methods Sigma metrics of 16 chemistry analytes were compared across 4 instruments system using CAP data from three reports (C-A 2023, C-C 2023 and C-B 2022). The 4 systems evaluated were Abbott Alinity ci, Beckman AU, Roche COBAS c500/c303 and Siemens Atellica CH. Method imprecision was estimated for each assay using the cumulative coefficient of variation or standard deviation for each assay at a single QC concentration and calculating the average sigma. Since sigma levels can be concentration-dependent, an equivalent CAP sample concentration was chosen for each instrument system evaluation. Method bias was estimated by evaluating each method QC mean to the peer group mean. Sigma values were calculated for each method as Sigma = (TEa - |Bias|) / Precision using the allowable total error from 2014 Clinical Laboratory Improvement Amendments (CLIA) proposed acceptance limits. Average Sigma values were generated for each analyte and graded as an optimal Sigma score. Results The sigma scores varied across assays and instrument systems. Abbott demonstrated the best overall performance. Specifically, the Abbott Alinity system had the highest number (7/16, 44%) of assays at 5 sigma or higher, with Siemens showing the lowest number of assays at 5 Sigma or higher (1/16, 6%). Of the 16 assays evaluated, Abbott has the fewest assays at or below the 3 sigma threshold (5/16) when compared to Roche (7/16), Beckman (7/16), and Siemens (9/16). Sigma scores were comparable between the Abbott ARCHITCT and Alinity clinical chemistry systems. Conclusions Sigma metrics are useful in assessing the performance of clinical assays. Assays with high Sigma have better performance due to lower imprecision and higher accuracy. None of the instrument systems demonstrated optimal six sigma performance for all analytes. However, Abbott demonstrated the best overall performance.

B-127 The Effect of Hemolysis on Potassium Measurement in a Community Setting: The Marching Error

Abstract Background Potassium is one of the most sensitive analytes to in-vitro hemolysis. To detect this error, modern clinical chemistry analyzers calculate the hemolysis index (HI) to estimate the degree of specimen hemolysis. Recently, Roche Diagnostics lowered the acceptable potassium HI limit from 100 to 20 and recommended laboratories avoid using specimens with an HI>20. The goal of this study was to determine a clinically acceptable HI cut-off for potassium at our community reference laboratory, relying on patient data from routine laboratory operation. Methods Plasma venous potassium, sodium, and HI test results from community patients measured on Roche cobas 8000 ISE and c701 modules between September 2022 to December 2023 were extracted from the Roche Infinity Middleware (n=1,101,897). Data was divided into groups based on HI which ranged from 0 to 300. The sample pool with the lowest level of hemolysis (HI≤10) was defined as the base group. Mean and standard deviation of potassium for each HI group was calculated and the difference in the mean between each group compared to the base group was calculated as both absolute and percent ΔK. Percent changes in critical values for both potassium and sodium as a function of hemolysis were calculated for each HI group. Measurement uncertainty (MU) for potassium was calculated using a top-down approach. Data were analyzed in Rstudio and Microsoft Excel. Results The vast majority of potassium specimens (83.8%) were stratified into the HI base group (HI ≤10) and 96.8 % had an HI ≤ 20, the cut-off recommended by Roche. The mean potassium level for each HI group increased as the degree of hemolysis in the specimens became more elevated. A MU-derived analytically significant shift of ΔK>0.1 mmol/L was observed for the bin HI 21-30. Depending on the employed total allowable error limit, clinically significant shifts in mean potassium levels were observed at HI bin 41-50 (RCPA: ΔK>0.2 mmol/L) or HI bin 101-150 (EFLM-derived reference change value: ΔK>10.1% and CLIA: ΔK>0.5mmol/L. The shift in patient potassium values seen as HI increased led to a change in critical results reporting frequencies. In the base group (HI≤10), 0.06% and 0.07% of results had low (<2.6 mmol/L) or high (>6.2 mmol/L) critical potassium values, respectively. When HI was 101-300, 0.00 and 15.7% of results had low or high critical potassium values. A similar comparison performed with sodium did not show the same shift in reported critical values. Linear regression of ΔK plotted vs HI produced the equation ΔK=0.0051xHI, validating the equation of Martinez-Morillo and Alvarez published previously using paired hemolyzed/non-hemolyzed potassium laboratory data. Conclusions In community patients, in-vitro hemolysis produced analytically significant errors at an HI of 20. Clinically significant errors occurred between an HI of 40-100. Past HI 100, mean ΔKs of 0.5-1.20 mmol/L were seen in our population. This shift in patient values as a function of hemolysis led to a change in critical result reporting, suggesting the generation of both factious critically high potassium results and the masking of critically low potassium results in our patient population.

B-271 High Sensitivity Homogeneous Enzyme Immunoassay for Benzodiazepines and Metabolites

Abstract Background Benzodiazepines are widely prescribed for treating various conditions such as anxiety, insomnia, and seizures due to their sedative and anxiolytic properties. Despite their therapeutic benefits, concerns persist regarding their potential for misuse, dependence, and addiction. Urine drug screening immunoassays serve as an important tool in monitoring benzodiazepine usage, ensuring adherence to prescribed regimens, identifying misuse or abuse, and facilitating necessary medical interventions. However, limitations of benzodiazepine immunoassays are well-documented in literature, with issues surrounding their lack of sensitivity to glucuronidated and 7-amino metabolites, inability to detect newer benzodiazepines, and poor cross-reactivity with different benzodiazepines. ARK Diagnostics has developed a highly sensitive homogeneous enzyme immunoassay capable of detecting both classic and designer benzodiazepines, in addition to their glucuronide and 7-amino metabolites in human urine at a cutoff concentration 200 ng/mL, without the need for glucuronidase or sample pretreatment. Methods The ARKTM Benzodiazepine Plus Assay is a liquid-stable homogenous enzyme immunoassay consisting of two reagents. The assay uses temazepam as the 200 ng/mL cutoff calibrator. The performance characteristics of this assay, including precision, spiked recovery, specificity, and method comparison to LC-MS/MS, were evaluated on the Beckman Coulter AU680 automated clinical analyzer. Results The ARKTM Benzodiazepine Plus demonstrated acceptable precision, with no overlap between cutoff (200 ng/mL) and ±25% control levels (150 ng/mL and 250 ng/mL) in a histogram overlap analysis, and ≤3.6% CV in semi-quantitative mode. Spiked temazepam samples spanning the semi-quantitative assay range of 1000 ng/mL were recovered between 95.0% and 103.7% of the spiked levels. Thirty-eight benzodiazepines produced cross-reactivities >80%, including the following benzodiazepines and metabolites: lorazepam, clonazepam, diazepam, alprazolam, temazepam, oxazepam glucuronide, lorazepam glucuronide, temazepam glucuronide, 7-aminoclonazepam, and 7-aminoflunitrazepam. In method comparison studies, a total of 103 urine samples containing benzodiazepines with LC-MS/MS values ranging from 1.3 ng/mL to 3257.6 ng/mL were tested with the ARKTM Benzodiazepine Plus Assay. Eighty samples tested positive with values ≥200 ng/mL and 23 samples tested negative with values <200 ng/mL by the ARKTM Benzodiazepine Plus assay. Of the 23 samples that tested negative, 21 had LC-MS/MS values <200 ng/mL and 2 samples were identified as midazolam samples with metabolite a-OH-midazolam levels >200 ng/mL. Conclusions The ARKTM Benzodiazepine Plus Assay enables the sensitive, rapid, and reliable measurement of benzodiazepines and their metabolites in human urine, without the need for hydrolysis or pretreatment. The assay addresses the present constraints of currently available benzodiazepine immunoassays, including their insufficient sensitivity, limited cross-reactivity to metabolites, and the requirement for glucuronidase pretreatment. The ARKTM Benzodiazepine Plus Assay is applicable to a wide range of clinical chemistry analyzers.

A-209 Preanalytical Phase Errors Constitute the Vast Majority of Errors in Clinical Laboratory Testing

Abstract Background Laboratory errors can occur during the preanalytical, analytic, or post-analytic phase of testing and may pose a considerable threat to patient safety. Studies have estimated that pre-analytical error encapsulates ∼45-68% of laboratory errors and occurs in up to 1.52% of specimens. However, limitations of previously published studies include the use of manual error detection, reliance on manual transcription, small study sizes, and exclusion of common errors. Herein, we aim to identify the types and frequency of errors occurring in each phase of clinical laboratory testing using a large retrospective dataset across a broad range of errors detected in clinical laboratories. Methods This study was performed in the Barnes-Jewish Hospital core laboratory which provides testing for a 1,400-bed tertiary care hospital and included all tests performed for clinical chemistry, special chemistry, toxicology, automated hematology, blood gas testing, coagulation, non-infectious serology, infectious disease serology, urinalysis, and send out testing between January 2022 and May 2023. Errors were compiled from two separate sources. The first source of errors was captured from the laboratory information system (LIS, Cerner). These errors were flagged manually by laboratory staff in real time. The second source of error was a daily report manually curated by a trained medial laboratory scientist as part of routine, laboratory operating procedures and standard workflow. Results There were ∼40,000,000 individual results from ∼11,000,000 specimens during the study period and 87,317 errors observed (∼0.8% of specimens). Of these errors, specimens that were hemolyzed sufficiently to impact result but still reportable were the majority (41,047, 47.2%). When excluding minimal hemolysis, there were 46,270 errors documented. Among these, 44,847 (97.0%) were in the preanalytical phase, 451 (1.0%) were in the analytical phase, and 972 (2.0%) occurred in the postanalytical phase. Subcategorization of preanalytical errors revealed that most of the errors were related to hemolyzed samples requiring results to be suppressed (n=19,701), quantity not sufficient samples (n=8,068), clotted specimens (n=5,840), collection errors (e.g., wrong tube type, n=5,780), not on ice (n=1,369) and IV fluid contamination (n=1,122). In the analytical phase, the causes of error were interfering substances (n=279), QC out of range (n=65), instrument problems (n=58) and reagent issues (n=49). Among the postanalytical errors, 581 were comment errors, 216 were results entry errors, 131 were comments errors with potential impact on patient care, and 44 were dilution errors. Conclusions This study demonstrates that the vast majority of lab errors (∼97.0%) occurring during the preanalytical phase. The high incidence of preanalytical errors, especially errors related to sample integrity implies a need for enhanced tools and training to minimizing errors from specimen collections, maintenance of sample stability, transportation, and processing.

A biological age based on common clinical markers predicts health trajectory and mortality risk in dogs.

Predicting aging trajectories through biomarkers of biological aging can guide interventions that optimize healthy lifespan in humans and companion animals. Differences in physiology, genetics, nutrition, and lifestyle limit the generalization of such biomarkers and may therefore require species-specific algorithms. Here, we compared correlations of standard clinical blood parameters with survival probability in humans with those of the two most common mammalian companion animals, cats and dogs, and highlighted universal and species-specific relationships. Based on this comparative analysis, we generated and validated an algorithm that predicts biological age in canines using a longitudinal dataset with health records, blood count, and clinical chemistry from 829 dogs spanning over 12years. Positive deviations of biological from chronological age (AgeDev) measured by this composite score significantly correlated with a decreased survival probability (hazard ratio = 1.75 per 1year of AgeDev, p = 3.7e - 06). Importantly, in nearly half of the dogs whose biological age was accelerated by more than 1year, none or only a single individual marker scored outside its respective reference range, suggesting practical applications for the detection of unfavorable health trajectories. Analyzing samples from a unique 14-year life-long diet restriction study, we show that restricted caloric intake lowers biological age, an effect that can be quantified at midlife years before a difference in survival is observed. Thus, a biological age clock based on clinical blood tests predicts the health trajectories of dogs for use in research and veterinary practice.

Examination Of Pre-Testing Mistakes In A Newly Established Clinical Biochemistry Lab

Background: The pre-analytical phase in laboratory diagnostics remains a significant source of errors, directly impacting patient care. This study aimed to investigate the prevalence and types of pre-analytical errors at a tertiary care hospital. Methods: A total of 5345 samples were evaluated over two months. Errors were categorized into types, and their distribution across various departments was assessed. Results: The overall error rate was 9.7%. Mismatched or wrong vials emerged as the most frequent error at 25%. Hemolysed samples accounted for 17.3%, and inadequate samples contributed to 16.3% of the errors. Significant variability in error rates was observed across departments, with Medicine and Surgery departments showing the highest frequencies at 23.1% and 21.2%, respectively. Conclusion: Our findings underscore the pressing need for targeted interventions in the pre-analytical phase, especially concerning sample collection and handling procedures. Department-specific strategies, ongoing training, and monitoring are crucial for minimizing errors and ensuring patient safety

Hypercholesterolemia and laboratory reports: joint document from the Italian Society of Cardiology (SIC) and the Italian Society of Clinical Biochemistry and Clinical Molecular Biology - Lab Medicine (SIBioC)

Dyslipidemia is one of the most important risk factors for the development of atherosclerotic disease and its control, through well-proven therapies, allows an optimal risk management over time. LDL-cholesterol targets are well defined by international guidelines and based on individual cardiovascular risk. As guidelines evolve, also laboratory reports need to do the same, including lipid reference values by cardiovascular risk classes, to avoid misunderstandings and inappropriate lipid-lowering therapy withdrawal. The aim of the present joint document from the Italian Society of Cardiology (SIC) and the Italian Society of Clinical Biochemistry and Clinical Molecular Biology - Lab Medicine (SIBioC) is to analyze the importance of cardiovascular risk estimation, therapeutical targets, and crucial elements about dyslipidemia in laboratory tests, as well as to suggest a shared proposal for the report of lipid profile parameters to be applied to all clinical scenarios of our daily practice.

A [18F]FDG PET based nomogram to predict cancer-associated cachexia and survival outcome: A multi-center study

ObjectivesCancer patients with cachexia face poor prognosis and shortened survival. Early diagnosis and accurate prognosis prediction remain challenging. This multi-center study aims to develop and externally validate a nomogram integrating [18F]fluoro-2-deoxy-D-glucose ([18F]FDG) PET findings and routine clinical biochemistry tests for predicting cancer-associated cachexia, while also assessing its potential prognostic value. Research Methods & ProceduresA retrospective analysis of 658 cancer patients (390 in the development cohort, 268 in the validation cohort) utilized [18F]FDG PET/CT data from two centers. Logistic regression identified organ-specific standardized uptake values (SUVs) and clinical variables associated with cancer-associated cachexia. Diagnostic accuracy, discriminative ability, and clinical effectiveness were assessed using area under the curve (AUC), calibration curve, and decision curve. Nomogram predictability for overall survival was evaluated through Cox regression and Kaplan–Meier curves. ResultsThe combined nomogram incorporating age (odds ratio [OR] = 1.893; P = 0.012), hemoglobin (OR = 2.591; P < 0.001), maximum SUV of the liver (OR = 3.646; P < 0.001), and minimum SUV of the subcutaneous fat (OR = 5.060; P < 0.001) achieved good performance in predicting cancer-associated cachexia (AUC = 0.807/0.726, development/validation). Calibration and decision curve analyses confirmed its clinical effectiveness. Kaplan–Meier curves analysis showed that overall survival can be categorized using the combined nomogram (P < 0.001). ConclusionCombining radiological information from clinical standard [18F]FDG PET data from cancer patients with biochemical results in their routine clinical blood tests through a well-constructed nomogram enables predicting cachexia and its effect on the prognosis of cancer patients.

Physiological and behavioural implications of the portosystemic shunt in C57Bl/6J mice.

A significant fraction of the popular inbred C57Bl/6J mice show structural and biochemical features of the congenital portosystemic shunt (PSS). How this hepatic abnormality affects physiological and behavioural parameters has not been explored in detail. Here, we confirmed the frequent occurrence of the PSS in C57Bl/6J mice by three different methods. We screened a cohort of 119 C57Bl/6J mice for total bile acids (TBA) in plasma, identified 11 animals (9.2%) with high TBA (>11µm; 171.1 ± 76.8µm), and confirmed PSS presence in that subset by magnetic resonance angiography and 1H-magnetic resonance spectroscopy of brain metabolites in the hippocampal area. In addition to the high glutamine and low myo-inositol levels, we detected lower levels of several neurotransmitters and metabolites in the hippocampus, higher brain weight and volume, as well as enhanced brain glucose utilisation in the PSS mice. We also observed differences in peripheral organ weights, haematological cell counts and clinical chemistry parameters in C57Bl/6J mice with and without PSS. Animals with PSS were slightly hyperlocomotive, had better balance on the rotarod, showed altered gait properties, and displayed attenuated fear memory in the fear conditioning test. Furthermore, we revealed a significant alteration of the pharmacokinetic profile of diazepam in C57Bl/6J mice with PSS. Our data support previous reports of hepatic disturbances and demonstrate an altered neurobiological phenotype in C57Bl/6J mice with PSS. Such congenital differences between inbred C57Bl/6J littermates may significantly distort experimental outcomes of pharmacological, behavioural and genetic studies. KEY POINTS: A significant proportion of C57Bl/6J mice, an inbred strain popular in preclinical research, have congenital portosystemic shunts (PSS) that allow venous blood to enter systemic circulation bypassing the liver. In this study, we extended existing knowledge of PSS consequences, particularly with respect to the effects on brain structure and function. We demonstrated that C57Bl/6J mice with PSS differ from their normal counterparts in brain size and contents of several neuroactive substances, as well as in peripheral organ weights, rate of glucose utilisation, blood cell counts and blood clinical chemistry parameters. C57Bl/6J mice with PSS showed altered locomotor behaviour, performed worse in a memory test and had abnormal blood pharmacokinetics of a benzodiazepine drug after a single administration. PSS presence may significantly complicate the interpretation of experiments in C57Bl/6J mice; therefore, we propose that before their use in biomedical studies, these mice should be screened with a simple blood test.

Healthful plant-based diets are negatively associated with the rate of biological aging: A national study based on US adults

Plant-based diets are recognized for their health benefits. However, evidence on the association between plant-based diet quality and aging in the US population is limited. This study aimed to investigate the association between different plant-based diet indices, phenotypic age acceleration (PhenoAgeAccel), and biological age acceleration (BioAgeAccel). We hypothesized that healthful plant-based diets would negatively affect PhenoAgeAccel and BioAgeAccel in US adults. The cross-sectional analysis included 22,363 participants, and information was obtained from the National Health and Nutrition Examination Survey database. The quality of plant-based diet was assessed using three indices: overall plant-based diet index (PDI), healthful PDI (hPDI), and unhealthful PDI (uPDI). Phenotypic age (PA) and biological age (BA) was calculated based on a linear combination of chronological age and 12 multi-system clinical chemistry biomarkers in accordance with the previously established method. PhenoAgeAccel and BioAgeAccel are the residuals of the PA and BA. Weighted linear regression analyses were performed to evaluate the relationships between PDI, hPDI and uPDI, and PhenoAgeAccel and BioAgeAccel. After adjusting for all covariates, we observed that a 10-unit higher PDI score was associated with 0.80 years lower PhenoAgeAccel (β: −0.80, 95% confidence interval [CI]: -0.94,-0.67), and 1.91 years lower BioAgeAccel (β: −1.91, 95% CI: -2.42,-1.40). A 10-unit higher hPDI score was associated with 0.83 years lower PhenoAgeAccel (β: −0.83, 95% CI: -0.96,-0.70), and 1.76 years lower BioAgeAccel (β: −1.76, 95% CI: -2.18,-1.34). Conversely, a 10-unit higher uPDI score was associated with 0.77 years higher PhenoAgeAccel (β: 0.77, 95% CI: 0.66,0.89) and 1.21 years higher BioAgeAccel (β: 1.21, 95% CI: 0.80,1.62). These findings suggest that US adults may be able to slow the aging process by increasing adherence to a healthy plant-based diet.

An in vitro experimental study on the interference of glyphosate on the urease enzyme

Purpose: Exposure to glyphosate is increasing due to the density of agricultural areas in Türkiye. In this study, the possible interference effect of glyphosate on urease, an enzyme that is frequently used in the diagnosis and follow-up of many diseases and in the measurement of urea in biological samples was examined. Materials and Methods: First, glyphosate was observed to have a negative interference in experiments using solutions of varying concentrations of urea. Second, blood samples were examined using the urease-glutamate dehydrogenase (GLDH) and indirect nesslerization procedures to determine the effects of glyphosate on the results before and after its addition. To determine the morphological and chemical alterations, scanning electron microscope (SEM) and Fourier-transform infrared spectroscopy (FTIR) analyses were conducted, and binding patterns were established through molecular docking. Urea measurements conducted with urease-GLDH and indirect nesslerization demonstrated a negative interference on the results with glyphosate concentrations of 10–3, 10–4, and 10–5 M. Results: Morphological changes observed in the SEM analysis were supported by the 3228.25 (O-H), 1642.08 (C=C), and 1531.20 (N-O) cm–1 bonds formed in the FTIR analysis. Furthermore, the molecular docking analysis showed that glyphosate affected the urease via hydrogen bonding (Gly13, Ser12, Lys14, Thr15, and Asp37) and hydrophobic interactions (Val10, Asp37, and Glu98). It was hypothesized that these interacting amino acids limit the accessibility of the urease’s active catalytic conformation and/or impact the stability of the catalytic transition state. Conclusion: Glyphosate leads to negative interference in human serum urea assays, leading to incorrect test results in clinical biochemistry, microbiology, and agricultural laboratories. This effect should be considered when conducting analysis, and clinicians as well as hospital information management systems should be informed ahead of time, with special emphasis devoted to this interference.

Clinical Biochemistry in the Diagnosis of Chronic Pulmonary Diseases: Identifying Biomarkers and Innovative Treatment Strategies

Chronic pulmonary diseases, which include COPD, asthma, and pulmonary fibrosis, are difficult to diagnose and treat because of the different mechanisms underlying each disease. The purpose of this study was to evaluate the contribution of clinical biochemistry in the diagnosis of these diseases offering biomarkers that distinguish these diseases and direct new therapeutic approaches. The study was conducted on 120 patients who were randomly grouped into six groups depending on their lung state and therapy they received. To examine the significance of other biomarkers involving inflammation (CRP, IL-6, TNF-α, MMP-9), oxidative stress (MDA, SOD), and leukocyte subpopulations (eosinophils, basophils) in the context of the studied disease, we also determined their levels. Additional spirometric indices were also recorded during 6 months to examine the effects of various management approaches. The results showed that all the diseases had marked difference in biomarker levels and were elevated in COPD and pulmonary fibiosis compared to asthma. Pharmacological treatments like LABAs/LAMAs in COPD and antifibrotic agents in pulmonary fibrosis also showed beneficial alterations in biomarkers and spirometry and confirmed the relevance of a biomarker approach. In conclusion, the study emphasizes the need for the use of clinical biochemistry in the discrimination of chronic pulmonary diseases and proper management strategies of the disorder. It indicates that biomarker can help improve the overall accuracy within the diagnosis process and can also aid in the formulation of effective treatment plans for patients – and therefore improve patient outcomes.

The Analytical Performance Evaluation of Routine Clinical Chemistry Parameters by Six Sigma Approach: An Effective Tool for Laboratory Quality Management

Background: Clinical laboratories errors can impose serious adverse effects on patient management. Clinical laboratories can evaluate their analytical performance by effective quality management tool i.e. Six Sigma metrics.Objectives: To evaluate the analytical performance of routine chemistry parameters by Six Sigma approach.Methods: Cross sectional study carried out from July 2022 till February 2024 in the Chemical Pathology section of University of Lahore Diagnostic Lab and Research Center, Lahore. Analytical performance of nineteen routine chemistry parameters were evaluated by using the external and internal quality control material. Only those parameters were selected who enrolled in External Quality Assurance Scheme. Inclusion criteria for IQC following West gard rule +/- 2 SD while for EQAS results follow +/- 2 Z score. Sample size for 19 parameters analyzed in EQAS from July 2022 till December 2023 was 342. 2700 IQC samples were analyzed from August 2023 till February 2024. All control values were entered in Microsoft Excel 2013 and calculated manually by conventional equations.Results: Most of our laboratory parameters showed satisfactory analytical performance in between 3-6 when evaluated by six sigma metrics.Conclusion: Control frequency for parameters showed score &gt; 6 can be reduce for saving laboratory resources whereas parameters with sigma score around 3 needs more vigilant monitoring. Health care and laboratory outcome need high quality results to improve patient health. Six sigma tool allows laboratory to identify the right method, right rule, run controls at right frequency to enable the right patient outcome.

Neutrophil gelatinase-associated lipocalin as a biomarker for detection of early renal impairment in Iraqi patients with multiple myeloma.

To evaluate the serum neutrophil gelatinase-associated lipocalin levels in multiple myeloma patients as an indicator of disease progression. The case-control study was conducted at the Clinical Biochemistry Department of the National Centre of Haematology, Mustansiriyah University, Baghdad, Iraq, from October 2020 to July 2021, amd comprised diagnosed multiple myeloma patients and healthy controls of either gender aged 40-60 years. Neutrophil gelatinaseassociated lipocalin and renal functions were measured for all patients in addition to obtaining a complete history and physical examination. Data was analysed using MedCalc. Of the 60 sujects, 30(50) were cases with mean age 64±2.1 years and 30(50%) were controls with mean age 60 ±3.2 years. There were 18(68%) males among the cases and 17(55%) among the controls. In the cases group, mean levels of creatinine, urea and neutrophil gelatinase-associated lipocalin were 1.62±0.85mg/dl, 55.56±28.05mg/dl and 389.39±116.12pg/mL, respectively. The corresponding values for the controls were 0.9518±0.1623mg/dl, 30.17±8.47mg/dl and 120.82±68'52pg/ml. The neutrophil gelatinase-associated lipocalin cutoff level >190pg/ml in multiple myeloma patients was strongly associated with renal impairment (p<0.001). Neutrophil gelatinase-associated lipocalin was found to be an accurate indicator of early kidney disease in patients with de novo multiple myeloma.