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Equivalent results for the same measurand in clinical samples (CSs), measured using different end-user in-vitro diagnostic medical devices (IVD-MDs), are essential for the application of clinical practice guidelines for diagnosis, treatment, monitoring, or risk assessment. The International Organization for Standardization (ISO) document 17511:2020 specifies how to establish metrological traceability to the highest available reference system component to enable equivalent results among IVD-MDs. Commutability with CSs is an essential property of a reference material used as a calibrator in a calibration hierarchy. However, not all calibrators in a calibration hierarchy are required to be commutable; different calibration hierarchies have different requirements for which calibrators must be commutable with CSs. Because assessment of commutability is a substantial effort, it is therefore important to determine which calibrators need to be commutable when implementing a calibration hierarchy. We provide guidance on which calibrators must be commutable with CSs, when a correction for any noncommutability bias is appropriate, and when commutability of a calibrator with CSs is not required for various types of calibration hierarchies described in ISO 17511:2020.

Recognizing that race is a social and not a biological construct, healthcare professionals and the public have called for removal of race in clinical algorithms. In response, the National Kidney Foundation and the American Society of Nephrology created the Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Diseases to examine the issue and provide recommendations. The final report from the Task Force recommends calculating estimated glomerular filtration rate (eGFR) without a race coefficient using the recently published CKD-EPI 2021 creatinine (cr) and creatinine-cystatin C (cr-cys) equations. The Task Force recommends immediately replacing older eGFRcr equations (MDRD Study and CKD-EPI 2009) with the new CKD-EPI 2021 equation. In a 2019 survey by the College of American Pathologists, 23% of 6200 laboratories reporting eGFRcr used an incorrect equation that is not suitable for use with standardized creatinine measurements, 34% used the CKD-EPI 2009 equation and 43% used the MDRD Study 2006 equation re-expressed for standardized creatinine measurement. Rapid transition to using the CKD-EPI 2021 equation is an opportunity for laboratories to standardize to a single equation to eliminate differences in eGFRcr due to different equations used by different laboratories, and to report eGFR without use of race. We provide guidance to laboratories for implementing the CKD-EPI 2021 equations for both eGFRcr and eGFRcr-cys.

For almost 2 decades, equations that use serum creatinine, age, sex, and race to estimate glomerular filtration rate (GFR) have included "race" as Black or non-Black. Given considerable evidence of disparities in health and health care delivery in African American communities, some regard keeping a race term in GFR equations as a practice that differentially influences access to care and kidney transplantation. Others assert that race captures important non-GFR determinants of serum creatinine and its removal from the calculation may perpetuate other disparities. The National Kidney Foundation (NKF) and American Society of Nephrology (ASN) established a task force in 2020 to reassess the inclusion of race in the estimation of GFR in the United States and its implications for diagnosis and subsequent management of patients with, or at risk for, kidney diseases. This interim report details the process, initial assessment of evidence, and values defined regarding the use of race to estimate GFR. We organized activities in phases: (1) clarify the problem and examine evidence, (2) evaluate different approaches to address use of race in GFR estimation, and (3) make recommendations. In phase 1, we constructed statements about the evidence and defined values regarding equity and disparities; race and racism; GFR measurement, estimation, and equation performance; laboratory standardization; and patient perspectives. We also identified several approaches to estimate GFR and a set of attributes to evaluate these approaches. Building on evidence and values, the attributes of alternative approaches to estimate GFR will be evaluated in the next phases and recommendations will be made.

This chapter focuses on the phenomenal opportunity that is becoming and being an agriculture teacher. This chapter examines what it means to be a profession and evaluates agricultural education using seven criteria. This chapter also explains what it means to be a professionally prepared teacher. The traditional approach to teacher education is described, alternative pathways to certification are acknowledged, and the advantages and challenges posed by each approach are considered. The most important roles of a school-based agricultural education teacher are examined within the three-component model of agricultural education. The chapter also examines the characteristics of a good agriculture teacher, while emphasizing that it is important for agricultural education to be committed to becoming a diverse, equitable, and inclusive profession. Finally, the chapter summarizes key principles from codes of ethics and the Ag Teacher's Creed. These principles can guide teachers in making good behavioral choices.

Long COVID, a type of Post-Acute Sequelae of SARS CoV-2 infection (PASC), has been associated with sustained elevated levels of immune activation and inflammation. However, the pathophysiological mechanisms that drive this inflammation remain unknown. Inflammation during acute Coronavirus Disease 2019 (COVID-19) could be exacerbated by microbial translocation (from the gut and/or lung) to the blood. Whether microbial translocation contributes to inflammation during PASC is unknown. We found higher levels of fungal translocation – measured as β-glucan, a fungal cell wall polysaccharide – in the plasma of individuals experiencing PASC compared to those without PASC or SARS-CoV-2 negative controls. The higher β-glucan correlated with higher levels of markers of inflammation and elevated levels of host metabolites involved in activating N-Methyl-D-aspartate receptors (such as metabolites within the tryptophan catabolism pathway) with established neuro-toxic properties. Mechanistically, β-glucan can directly induce inflammation by binding to myeloid cells (via the Dectin-1 receptor) and activating Syk/NF-κB signaling. Using an in vitro Dectin-1/NF-κB reporter model, we found that plasma from individuals experiencing PASC induced higher NF-κB signaling compared to plasma from SARS-CoV-2 negative controls. This higher NF-κB signaling was abrogated by the Syk inhibitor Piceatannol. These data suggest a potential targetable mechanism linking fungal translocation and inflammation during PASC.

Establishing metrological traceability to an assigned value of a matrix-based certified reference material (CRM) that has been validated to be commutable among available end-user measurement procedures (MPs) is central to producing equivalent results for the measurand in clinical samples (CSs) irrespective of the clinical laboratory MPs used. When a CRM is not commutable with CSs, the bias due to noncommutability will be propagated to the CS results causing incorrect metrological traceability to the CRM and nonequivalent CS results among different MPs. In a commutability assessment, a conclusion that a CRM is commutable or noncommutable for use with a specific MP is made when the difference in bias between the CRM and CSs meets or does not meet a criterion for that specific MP when compared to other MPs. A conclusion regarding commutability or noncommutability requires that the magnitude of the difference in bias observed in the commutability assessment remains unchanged over time. This conclusion requires the CRM to be stable and no substantive changes in the MPs. These conditions should be periodically reverified. If an available CRM is determined to be noncommutable for a specific MP, that CRM can be used in the calibration hierarchy for that MP when an appropriately validated MP-specific correction for the noncommutability bias is included. We describe with examples how a MP-specific correction and its uncertainty can be developed and applied in a calibration hierarchy to achieve metrological traceability of results for CSs to the CRM’s assigned value. BACKGROUND: TERMINOLOGY FOR MEASUREMENT PROCEDURE, MEASURING SYSTEM, AND IN VITRO DIAGNOSTIC MEDICAL DEVICE: As explained in part 1 of this series (1), we use the term measurement procedure (MP) when referring to a written specification for equipment, reagents, calibrators, and other components for making a measurement. We use the term in vitro diagnostic medical device (IVD-MD) for a physical measuring system manufactured according to the MP specifications and used to make measurements on clinical samples (CSs). An IVD-MD can be manufactured by a commercial company or by a clinical laboratory for its own use as a laboratory developed test.

The purpose of the study was to evaluate the reasons why high school agriculture teachers remain in teaching. A descriptive census study was implemented on agriculture teachers (N=252) utilizing an online validated questionnaire in Iowa. A total of 119 agriculture teachers completed the questionnaire with a response rate of 47%. A four-point Likert-type scale from 1=strongly disagree, 2=disagree, 3=agree, and 4=strongly agree was used to measure reasons why teachers stay in the teaching. Mean and standard deviation was 2.88(.32) for overall reasons to stay in teaching demonstrating these reasons influenced teachers to remain in teaching. Findings shows more than half teachers (f=54, 45.4%) plan to remain in teaching for 11 or more years. Further crosstabulates analysis on years of teaching experience variable with three different plans to stay shows that substantial number of late-career teachers plan to stay in short time (50%), 33.7% mid-career teachers plan to stay for 11 or more years, and newly teachers plan to stay for less than 10 years (42.9%). Findings are consistent with literature that reported years of teaching experience which was a predictor for teacher retention.

A descriptive survey study was used to examine factors that influence high school agriculture teachers' intentions to continue teaching in Iowa. The online questionnaire was administered to 252 agriculture teachers, and 119 teachers completed the survey. A four-point Likert-type scale was used to measure agriculture teachers' intentions to continue teaching. The overall mean and standard deviation is 2.64 (.64) for the eight influential factors, which indicates that these factors slightly influenced teacher intentions to continue teaching. The multinomial logistic regression model using the stepwise forward method was used to predict the likelihood of individuals' plans to continue teaching. The model was statistically significant (χ2 = 39.97; p = 0.01), and the following significant, influential factors can explain 31 percent (Pseudo R2=.31) of the variance: teacher recognition (p=.001), teaching as a right career (p=.035), family expectation of staying (p=.035) and teaching makes oneself feel good (p=.040). Findings from this study support evidence from previous research that reported teachers with strong self-esteem and belief that teaching is the right career for them and will remain longer in the profession.

The Kidney Disease Improving Global Outcomes 2012 Clinical Practice Guideline on Chronic Kidney Disease (1) recommends calculating estimated glomerular filtration rate (eGFR) using equations developed by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) for adults ≥18 years (2) and by the Chronic Kidney Disease in Children (CKiD) for ages

This study includes clinical laboratories that participated in the first general chemistry proficiency testing survey in 2022 to assess awareness and adoption of new equations from the Chronic Kidney Disease Epidemiology Collaboration for estimated glomerular filtration rate (eGFR) that eliminated race-adjustment factors, including one based on creatinine and one based on creatinine and cystatin C.

Background In response to a national call for reevaluation of the use of race in clinical algorithms, the National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) established a Task Force to reassess inclusion of race in the estimation of glomerular filtration rate (eGFR) in the United States and its implications for diagnosis and management of patients with, or at risk for, kidney diseases. Process & Deliberations The Task Force organized its activities over 10 months in phases to: 1) clarify the problem and evidence regarding eGFR equations in the United States (described previously in an Interim Report), and in this Final Report 2) evaluate approaches to address use of race in GFR estimation and 3) provide recommendations. We identified 26 approaches for the estimation of GFR that did or did not consider race and narrowed our focus by consensus to five of those approaches. We holistically evaluated each approach considering six attributes: assay availability and standardization; implementation; population diversity in equation development; performance compared to measured GFR; consequences to clinical care, population tracking and research; and patient centeredness. To arrive at a unifying approach to estimate GFR, we integrated information and evidence from many sources in assessing strengths and weaknesses in attributes for each approach, recognizing the number of Black and non-Black adults affected. Recommendations #1) For U.S. adults (>85% of whom have normal kidney function), we recommend immediate implementation of the CKD-EPI creatinine equation refit without the race variable in all laboratories in the U.S. because it does not include race in the calculation and reporting, includes diversity in its development, is immediately available to all labs in the U.S., and has acceptable performance characteristics and potential consequences that do not disproportionately affect any one group of individuals. #2) We recommend national efforts to facilitate increased, routine, and timely use of cystatin C, especially to confirm eGFR in adults who are at risk for or have chronic kidney disease, because combining filtration markers (creatinine and cystatin C) is more accurate and would support better clinical decisions that either one marker alone. If ongoing evidence supports acceptable performance, the CKD-EPI eGFR-cystatin C (eGFRcys) and eGFR creatinine-cystatin C (eGFRcr-cys_R) refit without the race variables should be adopted to provide another first line test in addition to confirmatory testing. #3) Research on GFR estimation with new endogenous filtration markers and on interventions to eliminate race and ethnic disparities should be encouraged and funded. An investment in science is needed for newer approaches that generate accurate, unbiased, and precise GFR measurement and estimation without the inclusion of race, and that promote health equity and do not generate disparate care. Implementation This unified approach, without specification of race, should be adopted across the U.S. High-priority and multi-stakeholder efforts should implement this solution.

Manufacturers of in vitro diagnostic medical devices, clinical laboratories, research laboratories and calibration laboratories require commutable reference materials that can be used in the calibration hierarchies of medical laboratory measurement procedures used for human specimens to establish metrological traceability to higher order reference systems. Commutable materials are also useful in external quality assessment surveys. In order to achieve these goals, matrix-based reference materials with long-term stability, appropriate measurand concentrations and commutability with individual human specimens are required. The Clinical and Laboratory Standards Institute (CLSI) guideline C37-A (now archived) provided guidance to prepare commutable pooled serum reference materials for use in the calibration hierarchies of cholesterol measurement procedures. Experience using the C37-A guideline has identified a number of technical enhancements as well as applications to measurands other than cholesterol. This experience is incorporated into this updated protocol to ensure the procedure will continue to meet the needs of the medical laboratory. The updated protocol describes a procedure for preparing frozen human serum units or pools with minimal matrix alterations that are likely to be commutable with individual human serum samples. The protocol provides step-by-step guidance for the planning phase, collection of individual serum units, processing the units, qualifying the units for use in a pool and frozen storage of aliquots of pooled sera to manufacture frozen serum pools. Guidance on how to perform quality control of the final product and suggestions on documentation are also provided.

The primary laboratory tests for diagnosis of chronic kidney disease (CKD)9 are serum/plasma/blood creatinine with calculation of estimated glomerular filtration rate (eGFR) and urine albumin–creatinine ratio (UACR). Cystatin C is becoming a secondary test for estimating eGFR in some clinical situations. Urine total protein and the protein–creatinine ratio are also used to monitor patients with more advanced CKD. The US Renal Data System 2018 reports that data from the National Health and Nutrition Examination Survey provide an estimate that 15% of the US population meet the laboratory criteria for CKD based on the Kidney Disease Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guideline definition of GFR 30 mg/g (3 mg/mmol). In the years from 2010 to 2018, 80%–90% of laboratories in the US have reported eGFR along with creatinine, yet patient awareness of having CKD continues to be poor. In the 2013–2016 US National Health and Nutrition Examination Survey data, only 8% of people with eGFR 30 mg/g (3 mg/mmol) were aware of having CKD. In this Q&A, a panel of experts in laboratory medicine and in nephrology examine laboratory ordering, testing, and reporting practices and recommend how those practices can be improved to better serve patients with CKD. What is a kidney profile and when should it be ordered? Joseph Vassalotti: The American Diabetes Association, KDIGO, and the National Kidney Foundation (NKF)'s Kidney Disease Outcomes Quality Initiative recommend eGFR and UACR as the tests for CKD targeted for the major risk groups, including diabetes and hypertension. The combination of eGFR and UACR guides therapeutic interventions and predicts risk for CKD progression as well as cardiovascular events, and mortality. The UACR is …

International audience

Mobile supplemental hospitals were an important asset to community response in preparing for the recent pandemic. MED-1 is a Mobile Emergency Department that has adapted and evolved to the changing needs of communities in times of disaster and nondisaster. An overview of the asset (MED-1), the operations, and use is provided to demonstrate how mobile supplemental hospitals can effectively meet a range of healthcare needs. Innovative utilization of MED-1 has secured its future as an effective resource averaging 100 days of deployment per year.

OBJECTIVES Inflammatory cytokines are key regulators of inflammation, but current measurement approaches require venous blood to quantify low circulating concentrations associated with chronic, low-grade inflammation. This article describes a highly sensitive multiplex immunoassay protocol for the measurement of IL6, IL8, IL10, and TNFα in finger stick dried blood spot (DBS) samples. METHODS The protocol uses a multiplex electrochemiluminescent immunoassay platform. The following measures of assay performance were evaluated: reliability (inter-assay percent coefficient of variation; %CV), precision (intra-assay %CV), lower limit of detection (LLD), linearity of dilution, and agreement with results from matched plasma samples. RESULTS Analysis of three control samples across the assay range indicated an acceptable level of precision and reliability for each cytokine. Linearity of dilution returned average values that ranged from 104.1 to 127.6% of expected. Lower limits of detection for IL6, IL8, and IL10 were

Commutability is a property of a reference material (RM) which denotes that the analytical response in measurement procedures (MPs) observed for the measurand is the same for the RM as for clinical samples that contain the same amount of the measurand. Matrix-based secondary calibrators are required to be commutable with clinical samples to achieve metrological traceability of results from a clinical laboratory MP to higher order references. Results for clinical samples may not agree among different end-user MPs if a noncommutable RM is used in the calibration hierarchy for one or more of the MPs. Consequently, a useful RM is one that is commutable with clinical samples for all or most MPs in common use. If a matrix-based RM is noncommutable for one or a few MPs, a correction for the noncommutability bias may be added in the calibration hierarchy to enable the results for clinical samples to be metrologically traceable to the RM. Producing a large batch of matrix-based RM requires pooling single donations and making various modifications of the matrix such as spiking with exogenous substances, freezing or lyophilization. These modifications could potentially affect commutability of the RM and compromise its suitability. Documentation of commutability of matrix-based RMs used as calibrators is required by the International Organization for Standardization and the Joint Committee for Traceability in Laboratory Medicine. We describe how commutability was recognized as a critical requirement for metrological traceability and we present recommendations from the IFCC Working Groups on Commutability and on Commutability in Metrological Traceability.

Background The purpose of a medical laboratory test is to provide information on the pathophysiologic condition of an individual patient as an aid in diagnosis, therapy, or assessment of risk for a disease. For optimal laboratory service, results from different measurement procedures (MPs) for the same measurand should be equivalent (harmonized) within stated specifications, enabling the results to be used reliably for medical decisions. The term “harmonization” refers to any process that enables establishing equivalence of reported values among different end-user MPs. The term “standardization” refers to achieving harmonization by metrological traceability of patients’ results to higher order reference materials and/or reference measurement procedures. Content New procedures for harmonization and standardization were published in 2020 by the International Organization for Standardization (ISO) and by the IFCC. ISO 17511:2020 provides revised requirements for establishing metrologically traceable calibration hierarchies for end-user MPs used in clinical laboratories. ISO 21151:2020 provides new requirements to implement a harmonization protocol to address the situation when there are no fit-for-purpose certified reference materials or reference MPs available for a measurand. The IFCC Working Group on Commutability published recommendations for applying a correction for noncommutability of a certified reference material to enable using that material in a metrologically traceable calibration hierarchy for an end-user MP. Summary We review metrological traceability and how these new approaches will improve the capability to achieve harmonized results for clinical samples.

Objectives External quality assessment (EQA) with commutable samples is used for assessing agreement of results for patients’ samples. We investigated the feasibility to aggregate results from four different EQA schemes to determine the bias between different measurement procedures and a reference target value. Methods We aggregated EQA results for creatinine from programs that used commutable EQA material by calculating the relative difference between individual participant results and the reference target value for each sample. The means and standard errors of the means were calculated for the relative differences. Results were partitioned by methods, manufacturers and instrument platforms to evaluate the biases for the measurement procedures. Results Data aggregated for enzymatic methods had biases that varied from −8.2 to 3.8% among seven instrument platforms for creatinine at normal concentrations (61–85 μmol/L). EQA schemes differed in the evidence provided about the commutability of their samples, and in the amount of detail collected from participants regarding the measurement procedures which limited the ability to sub-divide aggregated data by instrument platforms and models. Conclusions EQA data could be aggregated from four different programs using different commutable samples to determine bias among different measurement procedures. Criteria for commutability for EQA samples as well as standardization of reporting the measurement methods, reagents, instrument platforms and models used by participants are needed to improve the ability to aggregate the results for optimal assessment of performance of measurement procedures. Aggregating data from a larger number of EQA schemes is feasible to assess trueness on a global scale.

Background Clinical laboratories use internal quality control (QC) data to calculate standard deviation (SD) and coefficient of variation (CV) to estimate uncertainty of results and to interpret QC results. We examined the influence of different instruments, and QC and reagent lots on the CV calculated from QC data. Methods Results for BioRad Multiqual frozen liquid QC samples over a 2-year interval were partitioned by QC and reagent lots. The mean and CV were calculated for each partition for each of three Abbott Architect c8000 instruments for measuring serum alanine amino transferase (ALT), creatinine (enzymatic), glucose and sodium. Results CVs differed among partitions and instruments for two QC levels by 5.8- and 3.3-fold for ALT, by 4.7- and 2.1-fold for creatinine, by 2.0- and 2.6-fold for glucose, and by 2.1- and 2.0-fold for sodium. Pooled CVs for two QC levels varied among instruments by 1.78- and 1.11-fold for ALT, by 1.63- and 1.11-fold for creatinine, by 1.08- and 1.06-fold for glucose, and by 1.24- and 1.31-fold for sodium. Conclusions The CVs from QC data varied substantially among QC and reagent lots and for different identical specification instruments. The CV used to estimate uncertainty for a measurement result or as the basis for interpreting individual QC results must be derived over a sufficient time interval to obtain a pooled CV that represents “typical” performance of a measuring system. An estimate of uncertainty provided to users of laboratory results will itself have uncertainty that can influence medical decisions.

A review of Martin Dzelzainis and Edward Holberton’s The Oxford Handbook of Andrew Marvell.

Harmonization is achieving equivalent results, within clinically meaningful limits, among different measurement procedures for the same laboratory test. Standardization means equivalent results are achieved by having calibration of measurement procedures traceable to a reference measurement procedure (RMP) or certified reference material (CRM). The International Organization for Standardization (ISO) has published standards for metrological traceability of results for patient samples through an unbroken chain of calibrations to CRMs and RMPs. The Joint Committee for Traceability in Laboratory Medicine lists CRMs, RMPs, and calibration laboratories that conform to the ISO requirements. Commutability of matrix-based CRMs with patient samples is an essential property for their successful use in a calibration hierarchy. ISO has published a new standard for applying a harmonization protocol to achieve metrological traceability when there is no suitable CRM or RMP. Laboratories can verify calibration traceability by comparing patient sample results with a RMP, using a commutable matrix-based CRM or participating in an external quality assessment program that uses commutable samples.

The kidney is an organ that eliminates metabolic waste molecules into the urine and maintains the concentrations of many organic molecules and electrolytes in the blood. The principle biomarkers for glomerular filtration are blood creatinine and cystatin C. These biomarkers are used in equations to estimate glomerular filtration rate (eGFR), which is the best overall indicator of kidney function. Urine albumin and creatinine are reported as the albumin/creatinine ratio (ACR), which indicates kidney damage to either the glomerulus or tubules. Patients at risk for chronic kidney disease (CKD), such as diabetics, hypertensives, those with cardiovascular disease, and certain ethnic groups should be screened for CKD using eGFR and urine ACR to identify CKD early enough that intervention can slow or prevent progression to end-stage disease. This chapter reviews the role of urine total protein, biomarkers for acute kidney injury, and analysis of kidney stones.