Evaluation of Coefficients of Variation for Clinical Chemistry Tests Based on Internal Quality Control Data Across 5,425 Laboratories in China From 2013 to 2022

Background

Clinical chemistry tests are most widely used in clinical laboratories, and diverse measurement systems for these analyses are available in China. We evaluated the imprecision of clinical chemistry measurement systems based on internal QC (IQC) data.

Methods

IQC data for 27 general chemistry analytes were collected in February each year from 2013 to 2022. Four performance specifications were used to calculate pass rates for CVs of IQC data in 2022. Boxplots were drawn to analyze trends of CVs, and differences in CVs among different groups were assessed using the Mann-Whitney U-test or Kruskal-Wallis test.

Results

The number of participating laboratories increased significantly from 1,777 in 2013 to 5,425 in 2022. CVs significantly decreased for all 27 analytes, except creatine kinase and lipase. Triglycerides, total bilirubin, direct bilirubin, iron, and γ-glutamyl transferase achieved pass rates >80% for all goals. Nine analytes with pass rates <80% based on 1/3 allowable total error were further analyzed; the results indicated that closed systems exhibited lower CVs than open systems for all analytes, except total protein. For all nine analytes, differences were significant between tertiary hospitals and non-tertiary hospitals and between accredited and non-accredited laboratories.

Conclusions

The CVs of IQC data for clinical chemistry have seen a continuous overall improvement in China. However, there is ample room for imprecision improvement for several analytes, with stricter performance specifications.

New solutions to old problems: A practical approach to identify samples with intravenous fluid contamination in clinical laboratories

OBJECTIVES

Contamination with intravenous (IV) fluids is a common cause of specimen rejection or erroneous results in hospitalized patients. Identification of contaminated samples can be difficult. Common measures such as failed delta checks may not be adequately sensitive nor specific. This study aimed to determine detection criteria using commonly ordered tests to identify IV fluid contamination and validate the use of these criteria.

METHODS

Confirmed contaminated and non-contaminated samples were used to identify patterns in laboratory results to develop criteria to detect IV fluid contamination. The proposed criteria were implemented at a tertiary care hospital laboratory to assess performance prospectively for 6 months, and applied to retrospective chemistry results from 3 hospitals and 1 community lab to determine feasibility and flagging rates. The algorithm was also tested at an external institution for transferability.

RESULTS

The proposed algorithm had a positive predictive value of 92 %, negative predictive value of 91 % and overall agreement of 92 % when two or more criteria are met (n = 214). The flagging rates were 0.03 % to 0.07 % for hospital and 0.003 % for community laboratories.

CONCLUSIONS

The proposed algorithm identified true contamination with low false flagging rates in tertiary care urban hospital laboratories. Retrospective and prospective analysis suggest the algorithm is suitable for implementation in clinical laboratories to identify samples with possible IV fluid contamination for further investigation.

Emerging technologies: analytical lab vs. clinical lab perspective. Common goals and gaps to be filled in the pursuit of green and sustainable solutions

Analytical chemistry is a broad area of science comprised of many sub-disciplines. Although each sub-discipline has its own dominant trends, one trend is common to all of them: greenness and sustainability. Efforts to develop more ecological and environmentally friendly methods have been ongoing for over a decade with initial attempts largely focusing on limiting the necessary volume of solvents required and eliminating the use of toxic solvents. Over time, the miniaturization of analytical devices gained popularity as a way of not only reducing chemical usage, but also enabling analyses using smaller sample volumes and more "remote" applications (e.g., on-site sampling and analysis). Of course, miniaturization poses numerous challenges for researchers, for instance, in relation to the method's sensitivity and reproducibility. Developments in the design of detection systems have largely helped to mitigate these issues, but they also often restrict the potential for on-site analysis. Therefore, attempts have been made to improve analysis throughout the entire analytical process, from sampling through sample preparation and instrumental analysis to data handling. Furthermore, clinical chemistry labs must adhere to certain regulations and use certified protocols and materials, which precludes the rapid implementation of solutions developed in research labs. What are the obstacles in translating such innovations to practical applications, and what inventions can make a difference in the future? The answers to these two questions define the trends in analytical chemistry in the field of medical analysis.

Advances in D-dimer testing: progress in harmonization of clinical assays and innovative detection methods

The D-dimer is a sensitive indicator of coagulation and fibrinolysis activation, especially valuable as a biomarker of intravascular thrombosis. Measurement of plasma D-dimer levels plays a crucial role in the diagnosis and monitoring of conditions such as deep vein thrombosis, pulmonary embolism, and disseminated intravascular coagulation. A variety of immunoassays, including enzyme-linked immunosorbent assays, latex-enhanced immunoturbidimetric assays, whole-blood aggregation analysis, and immunochromatography assays, are widely used in clinical settings to determine D-dimer levels. However, the results obtained from different D-dimer assays vary significantly. These assays exhibit intra-method coefficients of variation ranging from 6.4% to 17.7%, and the measurement discrepancies among different assays can be as high as 20-fold. The accuracy and reliability of D-dimer testing cannot be guaranteed due to the lack of an internationally endorsed reference measurement system (including reference materials and reference measurement procedures), which may lead to misdiagnosis and underdiagnosis, limiting its full clinical application. In this review, we present an in-depth analysis of clinical D-dimer testing, summarizing the existing challenges, the current state of metrology, and progress towards harmonization. We also review the latest advancements in D-dimer detection techniques, which include mass spectrometry and electrochemical and optical immunoassays. By comparing the basic principles, the definition of the measurand, and analytical performance of these methods, we provide an outlook on the potential improvements in D-dimer clinical testing.

Liquid foams as sensors for the detection of biomarkers

Bioassays are widely used in healthcare to detect and quantify biomarkers, such as molecules or enzymes, which are crucial in monitoring diseases and health conditions. In developed countries, healthcare professionals use specialized reagents and equipment's to perform these bioassays. However, in less-industrialized countries, the creation of low cost, fast, and technically simple bioassays is required. Herein, we propose a simple approach for detecting biochemical markers using host-guest complexes containing a surfactant. When the biochemical marker is present, the host-guest complex is disrupted, releasing the surfactant and producing foam. The read-out mechanism relies on the change of foam volume as function of biomarker concentration. This change is quantifiable by the naked eye and can be measured with a simple ruler. We claim that the use of foams as sensing tool is an attractive, inexpensive, fast, and easy to handle on-site detection method.

Critical appraisal of two Box-Cox formulae for their utility in determining reference intervals by realistic simulation and extensive real-world data analyses

BACKGROUND

The reference interval (RI) is defined as the central 95 % range of reference values (RVs) from healthy individuals. The ideal method for determining RIs is to transform RV distribution into Gaussian and estimate its 95 % range parametrically. One-parameter Box-Cox formula (1pBC) is widely used for correcting skewness (Sk) or kurtosis (Kt) in data distribution. However, 1pBC is not popular for computing RIs due to its unreliability in Gaussian transformation. While its two-parameter version (2pBC) is not used due to a challenge in fitting power (λ) and shift (α) parameters simultaneously. In this study, technical issues in fitting both formulae are assessed, and an alternative algorithm for successful use of 2pBC is proposed.

METHODS

For fitting 1pBC, optimal λ was determined by stepwise linear search. For 2pBC, optimal [λ, α] combination was pursued in two ways: by grid search of λ and α (2pBCgrid) or by using the grid search but keeping α-range close to the reference distribution (2pBCopt). Their accuracy and precision in determining RIs were compared by generating power-normal distributions simulating RVs of 23 major chemistry analytes. Additionally, their practical utilities were compared by analyzing 776 real-world datasets comprising test results of 25 analytes that were obtained from the global multicenter RV study of IFCC. For comparison, the performance of nonparametric method was evaluated in both settings.

RESULTS

For analytes with not-much-skewed distributions, unbiased estimation of RIs was accomplished by all methods. Nevertheless, when reference distributions are located far from zero, λ estimated by1pBC and 2pBCgrid fluctuated widely, which was attributable to virtually flat goodness-of-fit profile for [λ, α]. For highly skewed distributions, 1pBC caused bias in estimating RI and λ due to remotely peaked goodness-of-fit profile. Real-world data analyses revealed that 2pBCopt and 1pBC achieved Gaussian transformation (|Sk|<0.1 and |Kt|<0.3) in 82.4 % and 66.9 % among 776 datasets, respectively. Fitting bias signified by Kt<-0.4 was more common to 1pBC. The practical utility of 2pBCopt was unbiased prediction of analyte-specific distribution-shape (λ). Whereas nonparametric method gave highly variable RIs for both simulated and real-world datasets.

CONCLUSIONS

2pBCopt is suitable for calculating RIs and grasping distribution-shape from the estimated λ.

Blood cell differential count discretisation modelling to predict survival in adults reporting to the emergency room: a retrospective cohort study

OBJECTIVES

To assess the survival predictivity of baseline blood cell differential count (BCDC), discretised according to two different methods, in adults visiting an emergency room (ER) for illness or trauma over 1 year.

DESIGN

Retrospective cohort study of hospital records.

SETTING

Tertiary care public hospital in northern Italy.

PARTICIPANTS

11 052 patients aged >18 years, consecutively admitted to the ER in 1 year, and for whom BCDC collection was indicated by ER medical staff at first presentation.

PRIMARY OUTCOME

Survival was the referral outcome for explorative model development. Automated BCDC analysis at baseline assessed haemoglobin, mean cell volume (MCV), red cell distribution width (RDW), platelet distribution width (PDW), platelet haematocrit (PCT), absolute red blood cells, white blood cells, neutrophils, lymphocytes, monocytes, eosinophils, basophils and platelets. Discretisation cut-offs were defined by benchmark and tailored methods. Benchmark cut-offs were stated based on laboratory reference values (Clinical and Laboratory Standards Institute). Tailored cut-offs for linear, sigmoid-shaped and U-shaped distributed variables were discretised by maximally selected rank statistics and by optimal-equal HR, respectively. Explanatory variables (age, gender, ER admission during SARS-CoV2 surges and in-hospital admission) were analysed using Cox multivariable regression. Receiver operating curves were drawn by summing the Cox-significant variables for each method.

RESULTS

Of 11 052 patients (median age 67 years, IQR 51-81, 48% female), 59% (n=6489) were discharged and 41% (n=4563) were admitted to the hospital. After a 306-day median follow-up (IQR 208-417 days), 9455 (86%) patients were alive and 1597 (14%) deceased. Increased HRs were associated with age >73 years (HR=4.6, 95% CI=4.0 to 5.2), in-hospital admission (HR=2.2, 95% CI=1.9 to 2.4), ER admission during SARS-CoV2 surges (Wave I: HR=1.7, 95% CI=1.5 to 1.9; Wave II: HR=1.2, 95% CI=1.0 to 1.3). Gender, haemoglobin, MCV, RDW, PDW, neutrophils, lymphocytes and eosinophil counts were significant overall. Benchmark-BCDC model included basophils and platelet count (area under the ROC (AUROC) 0.74). Tailored-BCDC model included monocyte counts and PCT (AUROC 0.79).

CONCLUSIONS

Baseline discretised BCDC provides meaningful insight regarding ER patients' survival.

Model of implementing proficiency testing in Vietnam, a developing country

Backgrounds and aims

The aim of this study is to provide a good approach for a quantitative EQA scheme assigned value with limited resources.

Materials and methods

Twelve lyophilized EQA items were distributed to participants in 2021 from North to Southeast Vietnam to measure the concentration of nine parameters, including glucose, urea, creatinine, cholesterol, triglyceride, uric acid, AST, ALT, and GGT. The consensus value of the expert group and all participants were calculated and statistically compared to choose the most appropriate consensus value.

Results

Fifty-nine laboratories attended the EQA scheme, including an expert group using automatic biochemistry analyzers (AAs) and all participants with auto and semi-auto biochemistry (SAA) analyzers. Consensus values of six per nine parameters were different between the two groups for at least two EQA items, including glucose, creatinine, cholesterol, uric acid, AST, and ALT. The coefficients of variation of glucose, urea, creatinine, triglycerides, uric acid, and GGT in the expert group were significantly lower than those in all the participants.

Conclusion

Using the consensus values of expert groups as the assigned values of the EQA program is a relevant strategy to increase testing quality in developing countries with limited resources, such as Vietnam.

Nanosensors in the detection of antihypertension drugs, a golden step for medication adherence monitoring

Hypertension is associated with structural and functional changes in blood vessels with increased arteriosclerosis, vascular inflammation, and endothelial dysfunction. Decreased adherence (compliance) to antihypertensive medications contributes significantly to morbidity and mortality in hypertensive patients. Antihypertensive drugs (AHTDs) and lifestyle changes are the main cornerstones for treating hypertension. Several approaches have been described in the literature for determining AHTDs based on different analytical techniques. Amongst biosensors are one of the most attractive tools due to their inherent advantages. Biosensors are used for the detection of wide range of biomarkers as well as different drugs in past two decades. The main focus of the present study is to review the latest biosensors developed for the detection of AHTDs. Readers of the present study will be able to familiarize themselves with biosensors as advanced and modern diagnostic tools while reviewing the most widely used AHTDs. In the present study, the routine methods are first reviewed and while examining their advantages and disadvantages, biosensors have been introduced as ideal alternative tools.

Evaluation of the HealthID PSD microsampling device for the simultaneous determination of cholesterol, high-density lipoprotein, triglycerides, creatinine, and HbA1c in capillary blood

INTRODUCTION

The use of dried capillary microsamples for clinical chemistry testing is an interesting alternative to conventional phlebotomy. Sampling devices capable to produce plasma from whole blood application are particularly useful. The aim of this study was to validate theHealthID PSDmicrosampling device for the determination of cholesterol (CHOL), high-density lipoprotein (HDL), triglycerides (TRIG), creatinine (CRE), and glycated hemoglobin (HbA₁c) after collection of capillary blood.

METHODS

Dried blood and plasma extracts were analyzed using modified methods in an open-channel biochemistry analyzer. The plasma volume in the extracts was corrected by the concentration of chloride (CL). Linearity, imprecision, bias, stability, and comparability to conventional samples were evaluated.

RESULTS

Dried plasma assays presented total error (TE) within acceptable limits. The analytes were stable for up to 14 days at 40 °C. Predicted serum concentrations of CHO, HDL, TRI, and CRE and predicted whole blood levels of HbA₁c, using dried extracts measurements, did not presented systematic or proportional differences to serum and whole blood levels.

CONCLUSIONS

Dried sample extracts obtained with capillary blood applied to the HealthID PSD allowed the determination of CHO, HDL, TRI, CRE, and HbA₁c, as well as the calculation of LDL level, using only 5 drops of blood. This sampling strategy can be useful for population screening programs, particularly in Developing Countries.

Point-of-care testing of HbA1c levels in community settings for people with established diabetes or people at risk of developing type 2 diabetes: a systematic review and meta-analysis protocol

INTRODUCTION

Diabetes mellitus has increased in prevalence worldwide and is causing an increasing burden on health services. The best patient outcomes occur with early diagnosis to prevent health complications. Glycated haemoglobin (HbA1c) is used to assess glycaemic control over 3-6 months and inform clinical management. Point-of-care (POC) HbA1c devices can be used in community settings, independent of clinical laboratories. This review aims to evaluate how these devices have been implemented in community settings and what patient outcomes have been documented.

METHODS AND ANALYSIS

This protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis guidance. A systematic search was undertaken in October 2022, using the defined PICOS (population, intervention, comparison, outcomes, study type) statement to identify all relevant articles: CINAHL, Cochrane, PubMed, Scopus and Web of Science were searched (updated February 2023). Studies will be included if they report outcomes of community POC testing for HbA1c for people with diabetes or at risk of diabetes. We will review the PROSPERO database and trial registers.Title, abstract screening and full-text review will be carried out by two reviewers. The Cochrane risk-of-bias tool will be used to assess randomised studies and the National Institutes of Health (NIH) Quality Assessment tool for observational cohort and cross-sectional studies. Publication bias will be assessed visually with a funnel plot and statistical approaches if necessary. If a group of sufficiently comparable studies are identified, we will perform a meta-analysis applying a fixed or random effects model as appropriate. We will investigate heterogeneity using visual inspection of forest plots along with review of evaluative approaches such as Χ² and the I² statistic. Strength of evidence will be assessed using Grading of Recommendations, Assessment, Development and Evaluation.

ETHICS AND DISSEMINATION

Ethics approval is not required for this literature review. The results will be disseminated through peer-reviewed publication and conference presentations. Furthermore, this systematic review will be used to inform the design of a community pharmacy-based prediabetes intervention.

PROSPERO REGISTRATION NUMBER

CRD42023383784.

Bone Turnover Markers for Assessment of Anti-Resorptive Effect in Clinical Practice: A Good Idea Meets the Problem of Measurement Uncertainty

OBJECTIVES

Bone turnover markers (BTM) are measures for understanding the effect of anti-resorptives upon osteoclast activity. Post-hoc trial data suggests reduction in BTM of 40% may represent a target for defining appropriate response to therapy. We modeled clinical application of this target threshold in an individual patient setting where assay measurement uncertainty and biological variation are included.

DESIGN

Using serum C-telo-peptide (ß-CTX), we constructed hypothetical scenarios of ß-CTX measurement pre and post bisphosphonate therapy. Using typical ß-CTX assay characteristics (analytical coefficient of variation, CV 5.0%) and published intra-individual ß-CTX data for post-menopausal women (CV 18.0%), we calculated the post-therapy ß-CTX that must be seen on single repeat measure for 95% confidence that the observed result was ≥40% below baseline. Sensitivity analyses considered greater and lesser variations in the combined sources of variation.

RESULTS

The one-tailed 95% reference change value for any detectable therapeutic decrease in ß-CTX was 22%. However, to have 95% confidence of having achieved a reduction ≥ 40%, an observed ß-CTX decrease of ≥56% is required. Larger decreases are needed for scenarios of greater analytical or intra-individual variation.

CONCLUSIONS

Although population data suggest a ß-CTX decrease of 40% is commensurate with adequate therapeutic response to anti-resorptives, application to an individual patient where measurement and natural variation are present is problematic. ß-CTX decreases much greater than 40% are required to be confident of having achieved the optimal treatment response. It is uncertain whether this is a legitimate change to be expected in all individual patients and therefore clinical application of this threshold is uncertain.

Impact of repeated micro and macro blood sampling on clinical chemistry and haematology in rats for toxicokinetic studies

Non-clinical rodent safety studies are essential in the development of new medicines to assess for potential adverse effects. Typically, toxicokinetic samples are collected from a satellite group. AstraZeneca implemented repeated microsampling of main study animals as standard in the one-month small molecule regulatory toxicology studies. A retrospective analysis of the clinical chemistry and haematology data collected in 52 independent studies from the adult rat controls explored the impact of micro and macro sampling of main study animals. For the majority of variables, the blood sampling technique had no significant impact on the mean or range. For microsampling, a few variables had statistically significant effects on the mean signal but these were considered to have limited biological relevance and would therefore not introduce a meaningful bias to any toxicological evaluation. The macrosampling had the expected effects on the red cell parameters of haemoglobin, haematocrit and red blood count due to the larger blood volume draw. In contrast, microsampling showed no such changes. In conclusion, this large-scale retrospective analysis supports the use of microsampling, for toxicokinetics, of main study animals and enables us to conduct rodent toxicology studies without satellite animals and further reduce the number of animals used in toxicological assessments.

The incidence of spontaneous arrhythmias in telemetered beagle dogs, Göttingen Minipigs and Cynomolgus non-human primates: A HESI consortium retrospective analysis

INTRODUCTION

Characterization of the incidence of spontaneous arrhythmias to identify possible drug-related effects is often an important part of the analysis in safety pharmacology studies using telemetry.

METHODS

A retrospective analysis in non-clinical species with and without telemetry transmitters was conducted. Electrocardiograms (24 h) from male and female beagle dogs (n = 131), Göttingen minipigs (n = 108) and cynomolgus non-human primates (NHP; n = 78) were analyzed.

RESULTS

Ventricular tachycardia (VT) was observed in 3% of the dogs but was absent in minipigs and NHPs. Ventricular fibrillation (VF) was not observed in the 3 species. Ventricular premature beats (VPBs) were more frequent during daytime and atrioventricular blocks (AVBs) were more frequent at night in all species. A limited number of animals exhibited a high arrhythmia frequency and there was no correlation between animals with higher frequency of an arrhythmia type and the frequency of other arrythmias in the same animals. Clinical chemistry or hematology parameters were not different with or without telemetry devices. NHP with a transmural left ventricular pressure (LVP) catheter exhibited a greater incidence of VPBs and PJCs compared to telemetry animals without LVP.

DISCUSSION

All species were similar with regards to the frequency of ventricular ectopic beats (26-46%) while the dog seemed to have more frequent junctional complexes and AVB compared to NHP and minipigs. Arrhythmia screening may be considered during pre-study evaluations, to exclude animals with abnormally high arrhythmia incidence.

Artificial Intelligence Applications in Clinical Chemistry

Artificial intelligence (AI) applications are an area of active investigation in clinical chemistry. Numerous publications have demonstrated the promise of AI across all phases of testing including preanalytic, analytic, and postanalytic phases; this includes novel methods for detecting common specimen collection errors, predicting laboratory results and diagnoses, and enhancing autoverification workflows. Although AI applications pose several ethical and operational challenges, these technologies are expected to transform the practice of the clinical chemistry laboratory in the near future.

Validating a clinical laboratory parameter-based deisolation algorithm for patients with COVID-19 in the intensive care unit using viability PCR: the CoLaIC multicentre cohort study protocol

INTRODUCTION

To investigate whether biochemical and haematological changes due to the patient's host response (CoLab algorithm) in combination with a SARS-CoV-2 viability PCR (v-PCR) can be used to determine when a patient with COVID-19 is no longer infectious.We hypothesise that the CoLab algorithm in combination with v-PCR can be used to determine whether or not a patient with COVID-19 is infectious to facilitate the safe release of patients with COVID-19 from isolation.

METHODS AND ANALYSIS

This study consists of three parts using three different cohorts of patients. All three cohorts contain clinical, vital and laboratory parameters, as well as logistic data related to isolated patients with COVID-19, with a focus on intensive care unit (ICU) stay. The first cohort will be used to develop an algorithm for the course of the biochemical and haematological changes of the host response of the COVID-19 patient. Simultaneously, a second prospective cohort will be used to investigate the algorithm derived in the first cohort, with daily measured laboratory parameters, next to conventional SARS-CoV-2 reverse transcriptase PCRs, as well as v-PCR, to confirm the presence of intact SARS-CoV-2 particles in the patient. Finally, a third multicentre cohort, consisting of retrospectively collected data from patients with COVID-19 admitted to the ICU, will be used to validate the algorithm.

ETHICS AND DISSEMINATION

This study was approved by the Medical Ethics Committee from Maastricht University Medical Centre+ (cohort I: 2020-1565/300523) and Zuyderland MC (cohorts II and III: METCZ20200057). All patients will be required to provide informed consent. Results from this study will be disseminated via peer-reviewed journals and congress/consortium presentations.

Development of Tier 2 LC-MRM-MS protein quantification methods for liquid biopsies

In the pursuit of personalized diagnostics and tailored treatments, quantitative protein tests contribute to a more precise definition of health and disease. The development of new quantitative protein tests should be driven by an unmet clinical need and performed in a collaborative effort that involves all stakeholders. With regard to the analytical part, mass spectrometry (MS)-based platforms are an excellent tool for quantification of specific proteins in body fluids, for example focused on cancer. The obtained readouts have great potential in determining tumor aggressiveness to facilitate treatment decisions, and can furthermore be used to monitor patient response. Internationally standardized TNM classifications of malignant tumors are beneficial for diagnosis, however treatment outcome and survival of cancer patients is poorly predicted. To this end, the importance of the tumor microenvironment has endorsed the introduction of the tumor-stroma ratio as a prognostic parameter in solid primary tumor types. Currently, the stromal content of tumor tissues is determined via routine diagnostic pathology slides. With the development of liquid chromatography (LC)-MS methods we aim at quantification of tumor-stroma specific proteins in body fluids. In this mini-review the analytical aspect of this developmental trajectory is further detailed.

Different clinical features of children and adults in regional outbreak of Delta COVID-19

Background

This study compared clinical features of the Delta variant of coronavirus disease 2019 (COVID-19) in children and adults.

Methods

Clinical data included 80 children and 132 adults with the Delta variant of COVID-19, hospitalized in the Affiliated Hospital of Putian College between September and October 2021. The data was analyzed retrospectively.

Results

The proportion of mild patients in the children group (50%) was higher than that in the adults group (17.9%). Cough (25%, 20/80) and diarrhea (1.3%, 1/80) symptoms in children group were significantly less frequent. Compared with adults, there was no significant difference in the viral load of SARS-CoV-2 in samples collected by nasopharyngeal swabs. In children, lymphocyte count was higher [1.98 (0.25–4.25) vs 1.20 (0.29–4.27) ×10⁹/L], whereas the interleukin-6 level was lower [5.87 (1.50–61.40) vs 15.15 (1.79–166.30) pg/mL] than that in adults group. Additionally, the incidence of liver injury in children group was lower than that in adults group. There was no significant difference in the incidence of proteinuria (22/75 vs 45/112) between the two groups, but the serum creatinine level in children was lower [42.0 (28.0–73.0) vs 57.0 (32.0–94.0) µmol/L].

Conclusion

Compared with adults, children with the Delta variant of COVID-19 have differences in symptoms, clinical classification, inflammatory indices, and liver/kidney function injury. Children’s illness is relatively mild. Clinicians should pay attention to their differences and use drugs accurately.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07707-6.

Development and validation of an early warning score to identify COVID-19 in the emergency department based on routine laboratory tests: a multicentre case-control study

OBJECTIVES

Identifying patients with a possible SARS-CoV-2 infection in the emergency department (ED) is challenging. Symptoms differ, incidence rates vary and test capacity may be limited. As PCR-testing all ED patients is neither feasible nor effective in most centres, a rapid, objective, low-cost early warning score to triage ED patients for a possible infection is developed.

DESIGN

Case-control study.

SETTING

Secondary and tertiary hospitals in the Netherlands.

PARTICIPANTS

The study included patients presenting to the ED with venous blood sampling from July 2019 to July 2020 (n=10 417, 279 SARS-CoV-2-positive). The temporal validation cohort covered the period from July 2020 to October 2021 (n=14 080, 1093 SARS-CoV-2-positive). The external validation cohort consisted of patients presenting to the ED of three hospitals in the Netherlands (n=12 061, 652 SARS-CoV-2-positive).

PRIMARY OUTCOME MEASURES

The primary outcome was one or more positive SARS-CoV-2 PCR test results within 1 day prior to or 1 week after ED presentation.

RESULTS

The resulting 'CoLab-score' consists of 10 routine laboratory measurements and age. The score showed good discriminative ability (AUC: 0.930, 95% CI 0.909 to 0.945). The lowest CoLab-score had high sensitivity for COVID-19 (0.984, 95% CI 0.970 to 0.991; specificity: 0.411, 95% CI 0.285 to 0.520). Conversely, the highest score had high specificity (0.978, 95% CI 0.973 to 0.983; sensitivity: 0.608, 95% CI 0.522 to 0.685). The results were confirmed in temporal and external validation.

CONCLUSIONS

The CoLab-score is based on routine laboratory measurements and is available within 1 hour after presentation. Depending on the prevalence, COVID-19 may be safely ruled out in over one-third of ED presentations. Highly suspect cases can be identified regardless of presenting symptoms. The CoLab-score is continuous, in contrast to the binary outcome of lateral flow testing, and can guide PCR testing and triage ED patients.

Parametric and non-parametric estimation of reference intervals for routine laboratory tests: an analysis of health check-up data for 260 889 young men in the South Korean military

OBJECTIVES

Determination of reference intervals (RIs) using big data faces several obstacles due to heterogeneity in analysers, period and ethnicity. The present study aimed to establish the RIs for routine common blood count (CBC) and biochemistry laboratory tests in homogeneous, healthy, male Korean soldiers in their 20s using a large health check-up data set, comparing parametric and non-parametric estimation.

DESIGN

A multicentre, cross-sectional study.

SETTING

Seven armed forces hospitals in South Korea.

PARTICIPANTS

A total of 609 649 men underwent health examination when promoted to corporal between January 2015 and September 2021. 260 889 eligible individuals aged 20-25 were included in the analysis.

MAIN OUTCOMES AND MEASURES

The RIs were established by parametric and non-parametric methods. In the parametric approach, maximum likelihood estimation was applied to measure the Box-Cox transformation parameter and the values at the 2.5th and 97.5th percentiles were recalculated. The non-parametric approach adopted the Tukey's exclusion test and the values at the 2.5th and 97.5th percentiles were obtained. Classification by body mass index was also performed.

RESULTS

The obtained RIs for haematology parameters were comparable between devices. If the values followed a Gaussian distribution, parametric and non-parametric methods were well matched for haematology and biochemical markers. When the values were right-skewed, the upper limits were higher with parametric than with non-parametric methods. Participants with obesity showed higher RIs for CBC, some liver function tests and some lipid profiles than participants without obesity.

CONCLUSIONS

Using data from healthy, male Korean soldiers in their 20s, we proposed the RIs for CBC and biochemical parameters, comparing parametric and non-parametric estimation. As such approaches based on large data sets become more prevalent, further studies are needed to discriminate eligible individuals and determine RIs in an extrapolated sample.

Periodic Comparability Verification and Within-Laboratory Harmonization of Clinical Chemistry Laboratory Results at a Large Healthcare Center With Multiple Instruments

Background

Results from laboratories using multiple instruments should be standardized or harmonized and comparability-verified for consistent quality control. We developed a simple frequent comparability verification methodology applicable to large healthcare centers using multiple clinical chemistry instruments from different manufacturers.

Methods

Comparability of five clinical chemistry instruments (Beckman Coulter AU5800, Abbott Architect Ci16000, two Siemens Vista 1500, and Ortho Vitros 5600) was evaluated from 2015 to 2019 for 12 clinical chemistry measurements. Pooled residual patient samples were used for weekly verifications. Results from any instrument exceeding the allowable verification range versus the results from the comparative instrument (AU5800) were reported to clinicians after being multiplied by conversion factors that were determined via a linear regression equation obtained from simplified comparison.

Results

Over the five-year study period, 432 weekly inter-instrument comparability verification results were obtained. Approximately 58% of results were converted due to non-comparable verification. Expected average absolute percent bias and percentage of non-comparable results for non-converted and converted results after conversion action were much lower than those for data measured before conversion action. The inter-instrument CV for both non-converted and converted results after conversion action was much lower than that for measured data before conversion action for all analytes.

Conclusions

We maintained within-laboratory comparability of clinical chemistry tests from multiple instruments for five years using frequent low-labor periodic comparability verification methods from pooled residual sera. This methodology is applicable to large testing facilities using multiple instruments.

Research-Relevant Clinical Pathology Resources: Emphasis on Mice, Rats, Rabbits, Dogs, Minipigs, and Non-Human Primates

Clinical pathology testing for investigative or biomedical research and for preclinical toxicity and safety assessment in laboratory animals is a distinct specialty requiring an understanding of species specific and other influential variables on results and interpretation. This review of clinical pathology principles and testing recommendations in laboratory animal species aims to provide a useful resource for researchers, veterinary specialists, toxicologists, and clinical or anatomic pathologists.

Potentiometric urea biosensors

Excess nitrogen in the body is converted to urea in the liver, and urea is disposed as a waste product in urine. Urea concentration can change in body fluids such as blood due to the presence of certain disorders. Therefore, the determination of urea is of high importance in various areas including medical diagnosis, as well as food quality control and environmental monitoring. Potentiometric sensors have certain advantages over their alternatives, such as rapidity, portability, cost effectiveness, high sensitivity, easy operation and simple apparatus. Potentiometric urea biosensors based on enzyme urease have been developed using various materials including nanoparticles and films, and also using different methodologies. In this review, we covered potentiometric urea biosensors reported in the literature, and touched upon their certain structure characteristics and performance parameters including detection limit, working concentration range, response time and lifetime, all of which are of practical importance. Each potentiometric urea biosensor has its own advantages and drawbacks, thus the selection of appropriate method depends on the sample to be analyzed, its urea concentration range and other requirements of the particular application. Further research is needed in order to optimize the performance of these devices and to broaden their applicability.

Analysis of the sex-specific variability of blood parameters in data sets of the Mouse Phenome Database

Objective

The use of mice as animal models in biomedical research allows the standardization of genetic background and environmental conditions, which both affect phenotypic variability. As the use of both sexes in experiments is strongly recommended, sex-specific phenotypic variability is discussed with regard to putative consequences on the group size which is necessary for achieving valid and reproducible results. In this study, the sex-specific variability of 25 clinical chemical and hematological parameters which represent a comprehensive blood screen of laboratory mice, was analyzed in data sets which have been submitted to the Mouse Phenome Database.

Results

The overall analysis comprising all 25 clinical chemical and hematological parameters showed no evidence for substantial and robust general sex-specific variability. A large range of the ratio of the female and male coefficient of variation (CV) was found for every parameter among the respective strain data sets. This clearly demonstrated the appearance of unpredictable major interactions between genotype and environment regarding the sex-specific variability of the blood parameters analyzed.

Missed critical value callbacks due to middleware flaw

OBJECTIVES

In 2018, our clinical laboratory was alerted to back-to-back plasma sodium critical value callback failures on the same patient, occurring on different shifts and involving different technologists. Therefore, we set forth to investigate the root cause for the critical value callback failures.

DESIGN AND METHODS

We conducted a thorough investigation focused on the processes associated with critical value identification and notification for plasma sodium measurement performed on the Siemens Vista.

RESULTS

Our investigation uncovered a flaw in the Siemens CentraLink middleware software. A default dark blue bar in the top row of the results review display was determined to obscure the red color which highlights critical values for lab staff identification. Sodium was disproportionately impacted by this flaw, as it is commonly ordered as part of metabolic panels, and is listed first among the panel analytes in the top row of the CentraLink display. Retrospective data review comparing critical callback failure rates for sodium to potassium and hemoglobin confirmed that sodium had significantly higher critical callback failure rates than these other analytes. After alerting the product manufacturer, Siemens programmed the CentraLink display so that the top row was blank and devoid of patient results, so that the blue color in the top row would no longer obscure the red visual cue of a patient's critical result. Sodium critical value callback failures were reduced to 0% after this middleware display correction.

CONCLUSIONS

Middleware design flaws can have unexpected consequences on clinical laboratory operations. We encourage clinical laboratories to closely examine user interfaces utilized by laboratory staff, and be wary of potential impacts that the display format may have on results reporting.

Serum complement C3 and α2-macroglobulin are potentially useful biomarkers for inflammatory bowel disease patients

Aims

Ulcerative colitis (UC), characterized by chronic inflammation and its recurrence in the large intestine, is well known as inflammatory bowel disease (IBD). Suitable biomarkers specific for UC are poorly understood till date. We aimed to discover novel serum biomarkers for UC and identify good indicators that reflected the severity of UC.

Main methods

Serum samples were obtained from out-patients with IBD (n = 101) and healthy volunteers (HVs, n = 101). Serum proteins were subjected to high performance liquid chromatography (HPLC) and sodium dodecyl sulfate-electrophoresis (SDS-PAGE) analysis. After electrophoresis, proteins in the gel were identified by mass spectrometry. Further, the protein concentration was measured by enzyme-linked immunosorbent assays (ELISAs). Based on the results, correlations between the serum levels of these proteins and the disease activity index scores for UC were statistically evaluated.

Principal findings

HPLC showed that chromatograms of serum proteins from HVs apparently differed from those of patients with IBD. Eleven protein bands, which were different in their protein concentrations from those in HVs, were separated by SDS-PAGE accordingly. Among them, complement C3 (c-C3) and α₂-macroglobulin (α₂-MG), with high protein scores, were identified by mass spectrometry. The serum concentration of c-C3 in patients with IBD was higher than that in HVs. However, the level of α₂-MG in patients with IBD was significantly lower than that in HVs. Hence, the serum levels of c-C3 and α₂-MG could be good indicators of the severity of UC.

Conclusion

Serum c-C3 and α₂-MG are suitable biomarkers for monitoring the condition of patients with UC.

Preanalytical Challenges During Capillary Fingerstick Sampling Preclude Its Widespread Use in Adult Hospitalized Patients

OBJECTIVES

Patient compliance with laboratory testing is one of the most underrecognized challenges in developing a treatment plan for acute and chronically ill patients. The ability to offer alternatives to standard venipuncture blood draws would greatly increase a laboratory's ability to provide testing to patients and health care providers.

METHODS

We performed a prospective observational study on paired venous and fingerstick capillary blood samples from admitted patients undergoing vancomycin therapy. Paired specimens were analyzed for vancomycin and a basic metabolic panel (BMP: calcium, carbon dioxide, chloride, potassium, sodium, creatinine, glucose, serum urea nitrogen) on the core laboratory's automated chemistry and immunochemistry platforms.

RESULTS

A total of 59 paired fingerstick and venous blood specimens from 56 unique inpatients were analyzed. Paired samples were comparable for all the analytes tested with the exception of bicarbonate and potassium, which were significantly different among the capillary sample group. Patients required multiple fingers be lanced in 15% of cases to obtain sufficient blood to carry out the testing. Capillary sample rejection rates due to insufficient volumes were as high as 30% in the initial 30 patients enrolled in the study.

CONCLUSIONS

Vancomycin and the BMP, with the exception of potassium and bicarbonate, were determined to be analytically comparable. However, significant preanalytical issues should preclude laboratories and providers from more widespread adoption of fingerstick-derived capillary blood as an alternative sampling method except in the most extenuating of circumstances.

Acute and repeated-dose toxicity of Echinops kebericho Mesfin essential oil

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No mortality was observed up to 2000 mg/kg dose in acute toxicity study of Echinops kebericho essential oil.

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On repeated-dose toxicity study, essential oil treated groups and controls did not show significant variations.

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No significant variation was observed in food consumption, body and organ weight, and histopathology between treated and control groups.

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Urea, albumin, aspartate aminotransferase, andorgan weight of kidney significantly varied between some treated groups compared to control.

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Significant variations were observed between male and female in many parameters.

Echinops kebericho Mesfin is used for the management of various diseases and fumigation during child birth. This study investigated acute and repeated-dose toxicity of E. kebericho M. essential oils (EOs). The study was conducted in Swiss albino mice. Organ weight, histopathology and clinical chemistry were analyzed. The dose and duration of treatment were defined in accordance with Organization for Economic Co-operation and Development (OECD) guideline.

No mortality was observed in acute oral dose toxicity study up to 2000 mg/kg per body weight. Compared to control group, treated groups did not show significant abnormalities in body weight and most parameters of clinical chemistry parameters and relative organ weight in repeated-dose toxicity study. However, urea, albumin, aspartate aminotransferase, and relative organ weight of right kidney showed variations in treated groups compared to control group. All treated groups and control group showed normal histology except lymphocytic infiltrates observed on the kidney with 200 mg/kg treated female group. The current study revealed that EO of E. kebericho M. could be considered well tolerated in acute and repeated-dose exposure. Further, teratogenic, mutagenic, carcinogenic, and sub-chronic and chronic toxicity studies are warranted.

Standardizing and increasing the utility of lipidomics: a look to the next decade

Introduction: We present our views on the current application of mass spectrometry (MS) based lipidomics and how lipidomics can develop in the next decade to be most practical use to society. That is not to say that lipidomics has not already been of value. In-fact, in its earlier guise as metabolite profiling most of the pathways of steroid biosynthesis were uncovered and via focused lipidomics many inborn errors of metabolism are routinely clinically identified. However, can lipidomics be extended to improve biochemical understanding of, and to diagnose, the most prevalent diseases of the 21^st century? Areas covered: We will highlight the concept of 'level of identification' and the equally crucial topic of 'quantification'. Only by using a standardized language for these terms can lipidomics be translated to fields beyond academia. We will remind the lipid scientist of the value of chemical derivatization, a concept exploited since the dawn of lipid biochemistry. Expert opinion: Only by agreement of the concepts of identification and quantification and their incorporation in lipidomics reporting can lipidomics maximize its value.

Eponyms in clinical chemistry

BACKGROUND

Eponyms are commonly used in medicine, but there are no specific studies of the use of eponyms in clinical chemistry.

METHODS

Clinical chemistry eponyms were manually collected from books, review articles and journal articles from 1847 through 2020. Eponym usage was examined by searching titles and abstracts in PubMed. Custom Python scripts were used to first permute eponyms into multiple forms, and then to search PubMed using Biopython. The eponyms identified in PubMed were further focused on 2 clinical chemistry journals Clinica Chimica Acta [CCA] and Clinical Chemistry [CCJ].

RESULTS

The manual collection identified >300 eponyms in clinical chemistry. The Biopython search of PubMed identified a subset of 97 unique eponyms in 33,232 articles. PubMed identified 26 eponyms used in 130 CCA articles; whereas a full-text search identified 1187 articles. In comparison, PubMed identified 36 eponyms used in 158 CCJ articles; whereas a full-text CCJ search identified 708 articles. PubMed shows that the journals CCA and CCJ had a peak number of eponym citations in 1977 followed by a steady decline.

CONCLUSIONS

Eponyms have been frequently used in clinical chemistry with 97 eponyms in common use in PubMed. Overall, the use of clinical chemistry eponyms appears to be declining.

COVID-19 associated variations in liver function parameters: a retrospective study

BACKGROUND

Characteristics of laboratory findings of COVID-19 patients are of great significance for diagnosis and treatment. Studies that have analysed the variations in hepatic profile in correlation with the inflammatory markers in SARS-CoV-2 are limited.

METHODS

We retrospectively analysed liver function tests and inflammatory markers of 170 admitted patients with confirmed COVID-19 in the tertiary care centre, Post Graduate Institute of Medical Education and Research (PGIMER), India, using Roche Cobas Autoanalyzer.

RESULTS

Number of patients with normal liver enzyme levels were 63 (41.5%), while with raised levels of any of the liver enzymes were 89 (58.5%), out of which 43 (48.31%) had liver injury which manifested as increased severity in terms of intensive care unit (ICU) requirement (p=0.0005). Significantly raised levels of liver enzymes and liver injury were observed with age (p<0.0001) and in males (p=0.004). Significantly decreased levels of albumin and total proteins and increased levels of total bilirubin (p<0.0001) were seen in patients with abnormal liver enzyme levels and liver injury as compared to patients with normal levels. Significant increase in the levels of alanine transaminase and gamma-glutamyl transferase was seen on the 7th day, CRP and ferritin (p<0.0001) peaks were observed on 2nd and 3rd day respectively. A significant positive correlation was found between the levels of these inflammatory markers and liver function parameters.

CONCLUSIONS

More than half of patients admitted to the hospital with SARS-CoV-2 infection had an abnormal liver function which was found to be associated with raised levels of inflammatory markers. Significantly higher proportions of patients with abnormal liver function were elderly and males and were at higher risk of progressing to severe disease.

A grading system from health to death using routine experimental indicators based on the pre-chronic disease status theory

BACKGROUND

To establish a system for assessing pre-chronic disease status (PCDS) whereby changes in biomolecule levels occur before the appearance of physical damage to body organs. We based our study on the common biomarkers of aging, disease and end-of-life processes.

METHODS

The red blood cell count as well as levels of albumin, creatinine and aspartate aminotransferase were used as indicators for measurement. The basic premise for determining PCDS was that the measured value was outside the reference range for a healthy individual. A binary outcome was determined according to reference range given by the laboratory undertaking the measurements. The Biological Age Index (BAI) was used to ascertain PCDS.

RESULTS

The four indictors that we chose were sensitive for end-of-life and aging. The BAI score for each age group increased significantly with increasing age. The BAI score of patients with cardiac disease, cerebrovascular disease, cancer or chronic obstructive pulmonary disease were mostly higher than those in healthy age-matched people.

CONCLUSION

A system for assessing PCDS centered on biomolecular detection and independent of the pathologic diagnosis could be effective.

Laboratory abnormalities in children with mild and severe coronavirus disease 2019 (COVID-19): A pooled analysis and review

Limited data exists to-date on the laboratory findings in children with COVID-19, warranting the conduction of this study, in which we pool the currently available literature data on the laboratory findings seen in children with mild and severe COVID-19. Following an extensive literature search, we identified 24 eligible studies, including a total of 624 pediatric cases with laboratory-confirmed COVID-19, which report data on 27 different biomarkers. We then performed a meta-analysis to calculate the pooled prevalence estimates (PPE) for these laboratory abnormalities in mild COVID-19. As data was too limited for children with severe COVID-19 to allow pooling, results were presented descriptively in a summary of findings table. Our data show an inconsistent pattern of change in the leukocyte index of mild and severe cases of COVID-19 in children. Specifically, changes in leukocyte counts were only observed in 32% of the mild pediatric cases (PPE: 13% increase, 19% decrease). In mild disease, creatine kinase-MB (CK-MB) was frequently elevated, with a PPE of 33%. In severe disease, c-reactive protein (CRP), procalcitonin (PCT), and lactate dehydrogenase (LDH) were frequently elevated. Based on data obtained from early COVID-19 studies, leukocyte indices in children appear inconsistent, differing from those reported in adults that highlight specific leukocyte trends. This brings into question the utility and reliability of such parameters in monitoring disease severity in the pediatric population. Instead, we suggest physicians to serially monitor CRP, PCT, and LDH to track the course of illness in hospitalized children. Finally, elevated CK-MB in mild pediatric COVID-19 cases is indicative of possible cardiac injury. This highlights the importance of monitoring cardiac biomarkers in hospitalized patients and the need for further investigation of markers such as cardiac troponin in future studies.

Data on interference indices in body fluid specimens submitted for clinical laboratory analysis

Clinical chemistry analysis of body fluids from non-blood or urine sources presents a technical challenge for clinical laboratories. Examples of body fluids include biliary secretions, cerebrospinal fluid, cyst contents, dialysate, gastric aspirates, peritoneal fluid, pleural fluid, stool, surgical drain fluid, synovial fluid, and wound exudates. The heterogeneous nature of these body fluids presents technical difficulties for analysis. For example, body fluid specimens may have presence of hemolysis, icterus, or lipemia (‘interference indices’) that can interfere with clinical chemistry analysis. In the related research article, we analyzed the distribution of these interference indices and body fluid samples submitted for analysis at an academic medical center central clinical laboratory and compared this to data from serum/plasma specimens. The data in this article provide the body fluid type, clinical chemistry testing ordered, interference indices, and whether the indices exceeded the manufacturer's recommendations in the package insert for serum/blood specimens. The analyzed data are provided in the supplementary tables included in this article. The dataset reported is related to the research article entitled “Review of interference indices in body fluids specimens admitted for clinical chemistry analyses” [1].

Review of interference indices in body fluid specimens submitted for clinical chemistry analyses

Objectives

The aims of this study were to retrospectively investigate interference indices in a wide range of body fluid specimens and compare these indices to those found in serum/plasma.

Design and Methods

This retrospective study evaluated interference indices for hemolysis, icterus, and lipemia in 2752 body fluid specimens submitted for clinical chemistry testing.

Results

The distribution of interference indices for body fluid samples was generally similar to that of serum/plasma interference indices. Hemolysis of specimens submitted for lactate dehydrogenase (LD) represented the most common interference for body fluid chemistries. Body fluids collected from postsurgical drain sites had a higher proportion of tests exceeding both icterus and lipemic limits compared to serum/plasma specimens.

Conclusions

Overall, degrees of hemolysis, icterus, and lipemia observed in body fluid specimens were in large part similar to serum/plasma specimens, with a few notable differences. Body fluids exhibited a higher proportion of samples with severe icterus or lipemia. Severely lipemic body fluid samples were significantly less likely to also be hemolyzed relative to severely lipemic serum/plasma specimens. LD was the test most commonly affected by interference across all body fluid types. False elevations in pleural fluid LD induced by hemolysis can lead to mis-classification of transudative effusions as exudative using Light’s criteria. The possible impact of interferences on clinical chemistry testing in body fluids is an important post-analytical consideration.

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Hemolysis, icterus, and lipemia were evaluated in 2752 body fluid specimens.

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Distributions of interference indices in body fluids generally mimicked those of serum/plasma.

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Pancreatic and pericardial fluids had the highest proportion of tests exceeding the hemolysis index.

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Compared to serum/plasma, drain fluids had relatively more tests exceeding both icterus and lipemic limits.

Changes in plasma biochemistry in breeding ring-billed gulls: Effects of anthropogenic habitat use and contaminant exposure

Gulls (Larids) have become successful at exploiting anthropogenic areas for foraging. However, little is known on the health implications of using anthropogenic habitats and on the associated exposure to environmental contaminants, particularly with respect to plasma biochemistry that is routinely used to diagnose physiological disorders and diseases. The objective of the present study was to investigate the effects of anthropogenic habitat use and exposure to ubiquitous halogenated flame retardants (HFRs) on plasma biochemistry of urban-breeding ring-billed gulls (Larus delawarensis) from one of the largest colonies in North America. Miniature GPS dataloggers were used to characterize foraging habitat use of individual gulls (n = 39) at the regional scale (urban, waste management facilities, agricultural fields, and St. Lawrence River) in the Montreal area (QC, Canada), and plasma was analyzed for a suite of biochemical measures (waste products, lipids, glucose, ions, proteins, and enzymes) and HFRs. Several confounding biological and environmental variables were also assessed including sex, body condition, time spent fasting while incubating, plasma thyroid hormone levels, time of day, capture date, and ambient temperature. As ring-billed gulls (males and females combined) spent more time foraging in urban areas, their plasma concentrations of cholesterol, albumin and activity of alkaline phosphatase increased significantly. Moreover, as the gulls spent more time foraging in agricultural fields, their plasma concentrations of phosphorous and activity of aspartate aminotransferase increased significantly. Only the activity of aspartate aminotransferase was significantly positively related to plasma HFR concentrations (PBDEs and dechlorane-related compounds). Time spent fasting while incubating, plasma thyroid hormone levels, body condition, time of day, and capture date were significantly related to certain plasma biochemical measures. The present results suggest that both the use of anthropogenic habitats for foraging and exposure to HFRs may affect the plasma biochemistry of ring-billed gulls breeding in the densely-populated Montreal area, suggesting potential adverse health effects for avian wildlife living in highly urbanized environments.

British Journal of Biomedical Science in 2019. What have we learned?

In 2019 the British Journal of Biomedical Science published 40 articles in the various disciplines that comprise biomedical science. These were one review, 22 original articles and 17 'In Brief' short reports. Of those citing original data, the majority were in cellular pathology (14 papers), clinical chemistry (9 papers), and microbiology (6 papers: 4 in bacteriology and 2 in virology). There were 3 papers in haematology and 2 in andrology, whilst 5 papers crossed traditional discipline boundaries (such as the molecular genetics of IL6, liver function tests, and hepatocellular carcinoma). Over two-thirds of papers used techniques in molecular genetics. The present report will summarise key aspects of these publications that are of greatest relevance to laboratory scientists.

Biobanking for discovery of novel cardiovascular biomarkers using imaging-quantified disease burden: protocol for the longitudinal, prospective, BioHEART-CT cohort study

INTRODUCTION

Coronary artery disease (CAD) persists as a major cause of morbidity and mortality worldwide despite intensive identification and treatment of traditional risk factors. Data emerging over the past decade show a quarter of patients have disease in the absence of any known risk factor, and half have only one risk factor. Improvements in quantification and characterisation of coronary atherosclerosis by CT coronary angiography (CTCA) can provide quantitative measures of subclinical atherosclerosis-enhancing the power of unbiased 'omics' studies to unravel the missing biology of personal susceptibility, identify new biomarkers for early diagnosis and to suggest new targeted therapeutics.

METHODS AND ANALYSIS

BioHEART-CT is a longitudinal, prospective cohort study, aiming to recruit 5000 adult patients undergoing clinically indicated CTCA. After informed consent, patient data, blood samples and CTCA imaging data are recorded. Follow-up for all patients is conducted 1 month after recruitment, and then annually for the life of the study. CTCA data provide volumetric quantification of total calcified and non-calcified plaque, which will be assessed using established and novel scoring systems. Comprehensive molecular phenotyping will be performed using state-of-the-art genomics, metabolomics, proteomics and immunophenotyping. Complex network and machine learning approaches will be applied to biological and clinical datasets to identify novel pathophysiological pathways and to prioritise new biomarkers. Discovery analysis will be performed in the first 1000 patients of BioHEART-CT, with validation analysis in the following 4000 patients. Outcome data will be used to build improved risk models for CAD.

ETHICS AND DISSEMINATION

The study protocol has been approved by the human research ethics committee of North Shore Local Health District in Sydney, Australia. All findings will be published in peer-reviewed journals or at scientific conferences.

TRIAL REGISTRATION NUMBER

ACTRN12618001322224.

Biosensing of D-dimer, making the transition from the central hospital laboratory to bedside determination

Since the disclosure of the fibrinogen degradation mechanism, around half a century ago, a significant number of papers have been published related to the clinical relevance of D-dimer, a molecule immune to additional enzymatic decomposition by plasmin. Due to the obliquity of regulating blood coagulation in pathological events, the number of diseases and conditions associated with abnormal levels of D-dimer includes deep vein thrombosis, pulmonary embolism, sepsis, myocardial infarction, disseminated intravascular coagulation, among many others. D-dimer not only is an important player in medical diagnosis but also its role as a prognosis biomarker is being revealed. However, the number of analytical alternative methods has not accompanied this trend, even though novel simple point-of-care devices would certainly boost the relevance of D-dimer in emergency medicine. Some reasons for that could be related to the fact that D-dimer is a challenging analyte present in complex samples like blood. In this manuscript, subsequent to a fibrinogen degradation process introduction, it is provided a historical overview of the early D-dimer assays, followed by an extended focus on innovative solutions, with a spotlight on the electrochemical bioanalytical devices. The discussion is accompanied with a critical analysis and concluding thoughts concerning future perspectives.

Tests of intestinal mucosal hyperpermeability: Many diseases, many biomarkers and a bright future

The number of disorders now linked to increased intestinal mucosal permeability implies that a substantial percent of the population is affected. Drug interventions targeting reduced tight junctional permeability are being pursued. Although hyper-permeability in itself is not a clinically recognized disease entity, its relationship to disease processes has driven interest in measuring, and even monitoring mucosal permeability in vivo. Along with improved knowledge of gut barrier physiology, advances have been made in tests and biomarkers of barrier function. Drawing from our experiences in the past decade, considerations and challenges faced in assessing in vivo intestinal permeability are discussed herein, along with indications of what the future might hold.

Ca2+-Binding Proteins of the EF-Hand Superfamily: Diagnostic and Prognostic Biomarkers and Novel Therapeutic Targets

A multitude of Ca²⁺-sensor proteins containing the specific Ca²⁺-binding motif (helix-loop-helix, called EF-hand) are of major clinical relevance in a many human diseases. Measurements of troponin, the first intracellular Ca-sensor protein to be discovered, is nowadays the "gold standard" in the diagnosis of patients with acute coronary syndrome (ACS). Mutations have been identified in calmodulin and linked to inherited ventricular tachycardia and in patients affected by severe cardiac arrhythmias. Parvalbumin, when introduced into the diseased heart by gene therapy to increase contraction and relaxation speed, is considered to be a novel therapeutic strategy to combat heart failure. S100 proteins, the largest subgroup with the EF-hand protein family, are closely associated with cardiovascular diseases, various types of cancer, inflammation, and autoimmune pathologies. The intention of this review is to summarize the clinical importance of this protein family and their use as biomarkers and potential drug targets, which could help to improve the diagnosis of human diseases and identification of more selective therapeutic interventions.

Body Fluid Testing at John F. Kennedy Medical Center in Liberia

OBJECTIVES

To apply a simple method to validate testing for albumin, glucose, lactate dehydrogenase (LDH) and total protein (TP) in peritoneal, pleural, and cerebrospinal fluids (CSF) at a hospital in Liberia.

METHODS

Serum and body fluid specimens were mixed to create 100% serum and 25%, 50%, 75%, and 100% fluid tubes, which were tested on a Biotecnica BT3500. Differences less than 10% between calculated and measured concentrations were considered acceptable.

RESULTS

The means (confidence intervals) of the percent differences were: albumin/peritoneal 12.8 (6.0-19.7), albumin/pleural 2.8 (1.3-4.2), albumin/CSF 4.8 (2.2-7.5), glucose/peritoneal 4.0 (1.9-6.0), glucose/pleural 4.4 (3.1-5.7), glucose/CSF 2.9 (1.8-4.0), LDH/peritoneal 9.5 (6.3-12.7), LDH/pleural 9.5 (5.4-13.6), LDH/CSF 9.2 (5.2-13.3), TP/peritoneal 7.6 (3.8-11.4), TP/pleural 3.8 (1.5-6.2), and TP/CSF 4.5 (1.0-8.1).

CONCLUSIONS

All mean differences except for one were less than 10%, allowing for the adoption of clinical testing. The mixing study is a low-cost method for quality-assured testing that can be performed by resource-limited laboratories.

An Overview of CE in Clinical Analysis

The development and general applications of capillary electrophoresis (CE) in the field of clinical chemistry are discussed. It is shown how the early development of electrophoresis was closely linked to clinical testing. The rise of gel electrophoresis in clinical chemistry is described, as well as the eventual developments that lead to the creation and the use of modern CE. The general principles of CE are reviewed and the potential advantages of this method in clinical testing are examined. Finally, an overview is presented of several areas in which CE has been developed and is currently being explored for use with clinical samples.

Relative quantification of plasma N-glycans in type II congenital disorder of glycosylation patients by mass spectrometry

BACKGROUND

Type II Congenital Disorders of Glycosylation (CDG-II) are a group of diseases with challenging diagnostics characterized by defects in the processing of glycans in the Golgi apparatus. Mass Spectrometry (MS) has been a valuable tool in the definition of CDG-II subtypes. While some CDG-II subtypes are associated with specific N-glycan structures, others only produce changes in relative levels, reinforcing the demand for quantification methods.

METHODS

Plasma samples from control individuals were pooled, derivatized with deuterated iodomethane (I-CD₃), and used as internal standards for controls and patients whose glycans were derivatized with iodomethane (I-CH₃), followed by MALDI MS, LC-MS and -MS/MS analyses.

RESULTS

Total N-glycans from fifteen CDG-II patients were evaluated, and 4 cases with molecular diagnosis were considered in detail: 2ATP6V0A2-CDG siblings, and 2 MAN1B1-CDG patients, one of them carrying a previously undescribed p.Gly536Val mutation.

CONCLUSIONS

Our methodology offers a feasible alternative to the current methods for CDG-II diagnosis by MS, which quantify glycan structures as fractions of the total summed signal across a mass spectrum, a strategy that lowers the variability of minor components. Moreover, given its sensitivity for less concentrated yet biologically relevant structures, it might assist the uncovering of novel diagnostic glycans in other CDG-II subtypes.

Automated and cost-efficient early detection of hemolysis in patients with extracorporeal life support: Use of the hemolysis-index of routine clinical chemistry platforms

PURPOSE

Patients with extracorporeal life support (ECLS) are at risk for hemolysis-related complications. Therefore, monitoring of free hemoglobin (fHb) levels is indicated. Conventional methods for fHb are laborious and not always available. Here we evaluated the suitability of the hemolysis-index (H-index), an internal quality control parameter of clinical chemistry platforms, as a clinical parameter for ECLS patients.

MATERIALS AND METHODS

The performance of the H-index assay was evaluated using standard procedures. Furthermore, H-index data from ECLS patients (n = 56) was analyzed retrospectively.

RESULTS

The H-index significantly correlated with fHb and showed good analytical performance. During ECLS 19.6% of the patients had an H-index above 20 in at least 2 consecutive blood draws, indicating significant hemolysis. In the patients with clot formation in the pumphead the H-index peaked above 100. Visible clots at other locations did not always coincide with hemolysis. H-index peaks were more prevalent in patients that died during ECLS support.

CONCLUSIONS

We conclude that the H-index is a suitable and cost-efficient alternative for the conventional fHb analysis with good analytic performance. The H-index aids in the early detection of hemolysis in patients with ECLS. A repeated H-index>20 was a predictor of mortality.

British Journal of Biomedical Science in 2018: what have we learned?

In 2018 the British Journal of Biomedical Science published one guideline (in reproductive science) and 40 research articles in the various disciplines the comprise biomedical science. The latter were 24 original articles and 16 'In Brief' short reports. Of these, 23 are of note to only one of the sub-disciplines (seven each to biochemists and microbiologists, six to cell pathologists, and one each to cytologists, immunologists and reproductive scientists). Reflecting the increasing complexity of laboratory science, thirteen papers crossed one boundary (three papers each relevant to biochemists and immunologists, and to haematologists and biochemists), whilst four papers were relevant to three or more disciplines. Indeed, biochemical techniques were used in 18 papers, microbiological techniques in 9, whilst histopathology was relevant to 11 papers. Notably, 20 papers used techniques in chromosome analysis and molecular genetics. The present report will summarise key aspects of these publications that are of greatest relevance to laboratory scientists.

Newly Emerging Drugs of Abuse and Their Detection Methods: An ACLPS Critical Review

Objectives

Illicit drug abuse has reached an epidemic level in the United States. Drug overdose has become the leading cause of injury-related deaths since 2008 due to the recent surge of opioid overdose by heroin, controlled prescription drugs, and nonmethadone synthetic opioids. Synthetic designer drugs such as synthetic cathinones ("bath salts") and synthetic cannabinoids ("Spice" and "K2") continue to emerge and attract recreational users.

Methods

The emergence of new drugs of abuse poses a steep challenge for clinical toxicology laboratories. Limited information about the emerging drugs and their metabolism, "rebranding" of the illicit drugs, and a lack of Food and Drug Administration-approved screening methods for these drugs contribute to this difficulty. Here we review detection methods that can aid in identifying emerging drugs of abuse.

Results

One promising approach is the utilization of untargeted drug screening by mass spectrometry. Historically, gas chromatography-mass spectrometry has been the gold standard.

Conclusions

Liquid chromatography-tandem mass spectrometry and liquid chromatography-high-resolution mass spectrometry offer improved detection capability of new drugs with simplified sample preparation, making it the new standard.

Determination of thiocyanate in exhaled breath condensate

Thiocyanate is a heme peroxidase substrate that scavenges oxidants produced during inflammation and regulates host defense. In cystic fibrosis (CF) patients, increased airway thiocyanate levels are associated with improved lung function. Research on airway thiocyanate is limited, however, because convenient non-invasive airway sampling methods, such as exhaled breath condensate (EBC), yield low concentrations that are difficult to detect with available assays. In the present study, we developed a method for the determination of thiocyanate in dilute samples using isotope dilution headspace gas chromatography-coupled high-resolution, accurate-mass mass spectrometry (GC-HRMS). The method reliably quantified as little as 4 pmol thiocyanate in EBC and could detect even lower amounts. We successfully measured thiocyanate in EBC from seven healthy donors, with a mean ± SD of 27 ± 16 nM and a median inter-assay coefficient of variation of 10.4% over six months. The method was applied to other biological fluids (plasma from the same visit as EBC donation; bronchoalveolar lavage fluid [BALF] from infants with CF; and healthy adult mouse BALF), giving reliable quantification of samples ranging from 10 nM to 100 µM. Thiocyanate concentrations in fluids besides EBC were (from lowest to highest): 0.73 ± 0.39 µM in BALF of healthy adult mice (n = 6); 1.4 ± 1.4 µM in BALF from infants with CF (n = 24); 46 ± 22 µM in the plasma of adult volunteers (n = 7). These results demonstrate the utility of this new method for clinical determination of thiocyanate in EBC and other biological fluids.

Bio-functionalized gold nanoparticles: Benign effect in Sprague-Dawley rats by intravenous administration

Gold nanoparticles offer a great promise in clinical research. Despite various applications of the metal nanoparticles it is challenging to implement in vivo in clinical applications. This aspect is deprived of understanding the biological mechanisms that occurs in the cells. In this report we have evaluated application of AuNP on the safety profile at different doses (100, 200, and 500 μg/kg Bwt/day) on intravenous administration in rats regularly for 28 days. The study was performed based on the OECD test guideline 407. No clinical signs and mortalities were observed in any groups of rat treated with AuNP. No evidence of toxicity was observed in any of the diverse studies performed which is noteworthy. The study includes survival, behavior, animal weight, organ morphology, blood biochemistry and tissue histology. The results indicate that tissue accumulation pattern of gold nanoparticles depends on the surface, size and doses of the nanoparticle. The accumulation of the particles does not produce subacute physiological damage.