Influence of Race Modifiers in Estimated Glomerular Filtration Rate Calculations on Medication Dosing, Access, and Transplant Eligibility.

The 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation for estimation of glomerular filtration rate (GFR) lower values for Black individuals relative to previous equations, which may change medication eligibility or trigger the need to reevaluate dosing decisions. Major drug classes such as antibiotics, antidiabetic medications, cardiovascular agents, medications for the treatment of psychiatric illness, and chemotherapy drugs all have estimated GFR thresholds for prescribing eligibility. However, the use of strict thresholds for medication eligibility should be heavily scrutinized, and individualized comprehensive approaches should be used for patients on the cusps of these thresholds.

Development and validation of an LC-MSMS method to quantify creatinine from dried blood spots.

Introduction: Screening for chronic kidney disease relies on accurate and precise creatinine measurements. Traditionally, creatinine is measured in serum or plasma using high-throughput chemistry analyzers. However, dried blood spots (DBS) can also be utilized to improve testing access.

A Review of Current Practices and Future Trends in Body Fluid Testing.

Background: Body fluid testing in the clinical chemistry laboratory is a cornerstone in the diagnostic workup of pathological effusions. Laboratorians may not be aware of the preanalytical workflows used in the collection of body fluids though the value is evident whenever processes change or issues arise. The analytical validation requirements can vary depending on the regulations dictated by the laboratories' jurisdiction and accreditor requirements.

Comparison of Five Common Analyzers in the Measurement of Chemistry Analytes in an Authentic Cohort of Body Fluid Specimens.

Objectives: Interpretation of body fluid (BF) results is based on published studies and clinical guidelines. The aim of this study is to determine whether the assays from five common commercial vendors produce similar results in BFs for 12 analytes in a BF cohort.

Methods: BFs (n = 25) and serum (n = 5) were analyzed on five instruments (Roche cobas c501, Ortho 5600, Beckman AU5800 and DXI800, Siemens Vista 1500, and Abbott Architect c8000) to measure albumin, amylase, total bilirubin, cholesterol, creatinine, glucose, lactate dehydrogenase (LDH), lipase, total protein, triglycerides, urea nitrogen, and carcinoembryonic antigen.

The Lines That Held Us: Assessing Racial and Socioeconomic Disparities in SARS-CoV-2 Testing.

Background: Racial disparities in SARS-CoV-2 prevalence are apparent. Race is a sociocultural construct, necessitating investigation into how sociocultural factors contribute.

Methods: This cross-sectional study linked laboratory data of adult patients between February 29 and May 15, 2020 with socio-demographics variables from the 2018 American Community Survey (ACS).

The 2018 AACC/SYCL PhD Clinical Chemist Compensation Survey.

Background: Doctoral level board-certified clinical chemists play an invaluable role in many facets of laboratory medicine and healthcare. However, information concerning their total compensation is sparse.

Content: A confidential self-reported compensation survey was conducted by the American Association for Clinical Chemistry's Society for Young Clinical Laboratorians (AACC SYCL) Core Committee from April 1 to April 17, 2018.

An Introduction to Drug Testing: The Expanding Role of Mass Spectrometry.

Measurement of drugs and their metabolites in biological fluids is the foundation of both therapeutic drug monitoring (TDM) and toxicology. The introduction of methods based on mass spectrometry (MS), coupled with gas or liquid chromatography, has revolutionized these areas. This chapter will introduce the reader to the application of MS to TDM and toxicology, the steps that should be considered during implementation and the processes that should be implemented to assure continued quality.

Method Performance of Bicarbonate and Electrolytes by Use of Duodenal Fluid for Assessment of Exocrine Pancreatic Function.

Background: Evaluation of exocrine pancreatic insufficiency is challenging for both clinicians and laboratories. Indirect pancreatic function tests such as serum trypsinogen, fecal elastase, and fecal fat measurements are moderately sensitive for diagnosis of advanced chronic pancreatitis but show reduced sensitivity and specificity for diagnosis of early disease. An alternative is the endoscopic pancreatic function test, which uses duodenal secretions after administration of IV secretin.

Reference intervals and diagnostic ranges for serum free κ and free λ immunoglobulin light chains vary by instrument platform: Implications for classification of patient results in a multi-center study.

Background: Serum free light chain (FLC) immunoglobulins are key biomarkers that aid in the diagnosis, prognosis and assessment of treatment response in patients with plasma cell disorders (PCD). Here we investigated the transference of manufacturer's reported κFLC, λFLC and κ to λ FLC reference intervals (RI) and established de novo FLC RI and diagnostic ranges on four instruments at three academic medical centers. In addition, we also compared the classification of patient FLC results using manufacturer's versus established RIs and diagnostic ranges.

Method performance and clinical workflow outcomes associated with meconium and umbilical cord toxicology testing.

Objective: Neonatal abstinence syndrome (NAS) is a rising concern with unknown long-term effects. It is apparent that higher cost of care, impact on the community and reduced quality of life are associated with similar etiologies (e.g.

Discovery of small molecule inhibitors for the C. elegans caspase CED-3 by high-throughput screening.

C. elegans has been widely used as a model organism for programmed cell death and apoptosis. Although the CED-3 caspase is the primary effector of cell death in C.

Method-dependent Discrepancies in Fetal Hemoglobin Quantification in Patients With Hemoglobin S.

Hemoglobin F (HbF) concentration is used in the diagnosis of certain hemoglobinopathies and accurate quantification is central to treatment of patients with sickle cell disease. The 2 most commonly used methods to quantify HbF are high performance liquid chromatography and capillary zone electrophoresis. This study reports discrepancies in HbF quantification between these methods when hemoglobin S is present in the sample.

Dystrophin-deficient dogs with reduced myostatin have unequal muscle growth and greater joint contractures.

Background: Myostatin (Mstn) is a negative regulator of muscle growth whose inhibition promotes muscle growth and regeneration. Dystrophin-deficient mdx mice in which myostatin is knocked out or inhibited postnatally have a less severe phenotype with greater total mass and strength and less fibrosis and fatty replacement of muscles than mdx mice with wild-type myostatin expression. Dogs with golden retriever muscular dystrophy (GRMD) have previously been noted to have increased muscle mass and reduced fibrosis after systemic postnatal myostatin inhibition.

Genetic myostatin decrease in the golden retriever muscular dystrophy model does not significantly affect the ubiquitin proteasome system despite enhancing the severity of disease.

Recent studies suggest that inhibiting the protein myostatin, a negative regulator of skeletal muscle mass, may improve outcomes in patients with Duchenne muscular dystrophy by enhancing muscle mass. When the dystrophin-deficient golden retriever muscular dystrophy (GRMD) dog was bred with whippets having a heterozygous mutation for the myostatin gene, affected GRMD dogs with decreased myostatin (GRippets) demonstrated an accelerated physical decline compared to related affected GRMD dogs with full myostatin. To examine the role of the ubiquitin proteasome and calpain systems in this accelerated decline, we determined the expression of the muscle ubiquitin ligases MuRF1, Atrogin-1, RNF25, RNF11, and CHIP: the proteasome subunits PSMA6, PSMB4, and PSME1: and calpain 1/2 by real time PCR in the cranial sartorius and vastus lateralis muscles in control, affected GRMD, and GRippet dogs.

The new collaborative path in medical device development: the medical device innovation consortium.

The United States medical device market is the world's largest with over $100 billion in sales in 2011. Despite robust industry growth, the efficiency of the FDA approval process for moderate-risk (Class II) and high-risk devices (Class III) requiring 510(k) submission or pre-market approval (PMA) has been criticized. Recently, the FDA's Center for Devices and Radiological Health (CDRH) announced the creation of a Medical Device Innovation Consortium (MDIC), a public-private partnership (PPP) to share knowledge in regulatory science.

Evaluation of digital images for identification and characterization of monoclonal immunoglobulins by immunofixation.

Objectives: High resolution digital imaging systems were recently introduced to capture and visualize serum protein electrophoresis results. In this study, we compared the performance of five, experienced interpreters using digital images and physical gels to identify and characterize monoclonal gammopathies by immunofixation.

Design And Methods: Immunofixation gels were generated using Sebia's HYDRASYS and digital images were captured with Sebia's Gelscan system.