Clinical Chemistry Podcast

Cardiac troponin is integral in the investigation of acute coronary syndromes. Modern high-sensitivity versions of troponin assays are able to detect very low concentrations and potentially identify disease sooner.

The Ebola outbreak in the fall of 2015 led to emergent responses by hospitals to prepare for potential patients. This included preparedness efforts by laboratories, which was challenging as they was evolving and at times contradicting information about how samples from patients under investigation for Ebola should be handled.

Initial detection and reporting by clinical microbiology laboratories is a sentinel marker for foodborne outbreak surveillance systems. Initiation of a public health investigation is reliant on the rapid initial identification of pathogens of interest. Diagnostics for Escherichia coli have evolved to reduce identification turnaround time, incorporating technologies for rapid identification (MALDI-TOF MS) and serogrouping (O157 antiserum or latex agglutination). Reporting of these isolates to a public health agency may initiate further laboratory investigations, such as pulsed-field gel electrophoresis, for confirmation that isolates may be related to a common source (clonal population).

It is no secret that laboratory tests are overordered in the clinical environment; a recent metaanalysis demonstrated that tests are overused by 20.6% on average. The ordering of unnecessary tests on such a massive scale may impact not only direct healthcare costs, but also patient safety, and may lead to unnecessary follow-up investigation and iatrogenic blood loss due to excess phlebotomy. Unfortunately, in large hospitals with high patient volumes, it would be impractical for laboratory directors to evaluate every test individually for appropriateness, and even more difficult to convince providers to change ordering practices. Meeting other evidence-based quality objectives in laboratory ordering is similarly labor-intensive.

Next generation sequencing is increasingly available in clinical laboratories, enabling the sequencing of more genes for relatively lower costs.

The practice of medicine is not always clear-cut. Healthcare providersare often faced with difficult decisions such as what test to perform on patients, what treatment should be given, and what type of follow-up is needed. Providers have a duty to enhance the wellbeing and minimize harm to their patients.

The role of branched-chain amino acids (BCAAs) in cardiovascular disease (CVD) remains poorly understood. We hypothesized that baseline BCAA concentrations predict future risk of CVD and that a Mediterranean diet (MedDiet) intervention may counteract this effect.

The basic problem shared by many of the biostatistical methods used in marker research is that they relate numbers to other numbers, rather than to anything that we might care about in the real world.

Pneumatic tube systems have become a primary way of automating the transport of clinical specimens in medical centers. These may travel within the floors of a building and also between buildings. Although this provides convenience and speed of transport, the excessive acceleration forces and the prolonged time and distance travelled have been linked to pre-analytical variation including hemolysis of blood specimens. As a result, it has been suggested that users regularly assess the forces encountered in a pneumatic tube system.

Postmarket surveillance is an important monitor of the safety of pharmaceuticals and medical devices after regulatory approval and entry to the market. Although premarket studies are substantial, costs prohibit examination of heterogeneous populations or rare events over long durations.

There are nearly 60,000 community pharmacies in the United States today. In addition to being sources of prescriptions and medications, they're also often a site for wellness visits, vaccinations, acute illness diagnosis and treatment, as well as monitoring of chronic disease. Pharmacies often offer a convenient alternative to physician offices because of their accessible locations and extended service hours. Approximately 18% of pharmacies in the U.S. have CLIA-waived status, which means they can perform any of the approximately 120 CLIA-waived tests. Many pharmacists help patients make drug dosage decisions in specialized centers such as coumadin in diabetes clinics. With pharmacists performing and interpreting more laboratory tests, what does this mean for the clinical laboratory community? Do pharmacists receive the proper training to perform and interpret laboratory tests? And how do we ensure the quality of testing?

Protease neprilysin is known to be responsible for the degradation of natriuretic peptides. A recent heart failure (HF) drug, LCZ696 (EntrestoTM), that combines a neprilysin inhibitor and an angiotensin II receptor inhibitor was suggested to augment circulating B-type natriuretic peptide (BNP) concentrations, making the results of BNP measurements diagnostically ambiguous. Because the main form of measured BNP in HF patients is represented by its uncleaved precursor, proBNP, it is important to know the susceptibility of proBNP to cleavage by neprilysin.

CREB-regulated transcription coactivator 3 (CRTC3) is found in adipocytes, where it may promote obesity through disruption of catecholamine signaling. We wished to assess whether CRTC3 is a soluble protein secreted by adipose tissue, explore whether CRTC3 is detectable and quantifiable in the circulation, and ascertain whether CRTC3 serum concentrations are related to metabolic markers in children.

The analysis of dried blood spots has been used routinely for newborn screening since the early 1970s, and the number of disorders screened has expanded substantially in recent years. However, there is a lack of evidence regarding minimum blood spot quality acceptance criteria for sample analysis.

For many years the determination of a routine lipid profile (total, LDL, and HDL cholesterol and triglycerides) has been done routinely in the clinical laboratory using a blood specimen that is collected in the fasting state.

Primary aldosteronism,also known as Conn's syndrome,is a form of endocrine hypertension that results from excess product of aldosterone by the adrenal glands.

More than 70 million couples worldwide are affected by infertility, with male-factor infertility accounting for about half of the cases. Semen analysis is critical for determining male fertility potential, but conventional testing is costly and complex. Here, we demonstrate a paper-based microfluidic approach to quantify male fertility potential, simultaneously measuring 3 critical semen parameters in 10 min: live and motile sperm concentrations and sperm motility.

Clostridium difficile is the most common cause of healthcare associated infections in the United States and is increasingly recognized as a pathogen in the community. This organism is considered to be one of the most urgent antibiotic resistant threats to public health, and can cause a variety of clinical manifestations ranging from asymptomatic to mild diarrhea, to toxic megacolon, and even death.

More than 70 million couples worldwide are affected by infertility, with male-factor infertility accounting for about half of the cases. Semen analysis is critical for determining male fertility potential, but conventional testing is costly and complex. Here, we demonstrate a paper-based microfluidic approach to quantify male fertility potential, simultaneously measuring 3 critical semen parameters in 10 min: live and motile sperm concentrations and sperm motility.

Gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes, but risk is reduced with identification and early treatment. Glucose measurements are affected by preanalytical sample handling, such as temperature of storage, phlebotomy–analysis interval, and use of a glycolysis inhibitor. We evaluated glucose concentrations and the incidence of GDM after strict implementation of the American Diabetes Association (ADA) preanalytical guidelines, compared with usual hospital conditions.

Evidence is accumulating that circulating 1,25-dihydroxyvitamin D [1,25(OH)2D] concentrations are inversely related to overall mortality.

Limited information is available about testosterone concentrations representative of the general US population, especially children, women, and non-Hispanic Asians.

Mass spectrometry–based in vitro diagnostic devices that measure proteins and peptides are underutilized in clinical practice, and none has been cleared or approved by the Food and Drug Administration (FDA) for marketing or for use in clinical trials. One way to increase their utilization is through enhanced interactions between the FDA and the clinical mass spectrometry community to improve the validation and regulatory review of these devices.

There are now numerous epidemiological studies that have demonstrated that low plasma concentrations of vitamin D are associated with not only bone related disorders, but with a wide variety of adverse health outcomes.

A driving force in the development of point-of-care diagnostics is to conveniently provide information without delay so that healthcare decisions can be made while the patient is on-site. Most point-of-care devices are based on immunochemical, electrochemicalor colorimetric techniques that can be miniaturized and made portable.

Analytically sensitive techniques for measuring minimal residual disease (MRD) in multiple myeloma (MM) currently require invasive and costly bone marrow aspiration. These methods include immunohistochemistry (IHC), flow cytometry, quantitative PCR, and next-generation sequencing. An ideal MM MRD test would be a serum-based test sensitive enough to detect low concentrations of Ig secreted from multifocal lesions.

A mass spectrometer is a sensitive and specific instrument." In some form or another, this is often the label applied to the platform by all manner of professions (chemists, physicists, biologists, physicians, clinicians, and laboratorians, novice and expert alike). This is a view of mass spectrometry (MS) through rose-colored glasses. It should be properly said that MS can be sensitive and specific, but not without due consideration for the measurement to be performed. In clinical laboratories, this measurement is the extraction, detection, and often, quantification of a compound of interest from a biological matrix.

Despite increasing prevalence of novel psychoactive substances, no human metabolism data are currently available, complicating laboratory documentation of intake in urine samples and assessment of the drugs' pharmacodynamic, pharmacokinetic, and toxicological properties. In 2014, THJ-018 and THJ-2201, synthetic cannabinoid indazole analogs of JWH-018 and AM-2201, were identified, with the National Forensic Laboratory Information System containing 220 THJ-2201 reports. Because of numerous adverse events, the Drug Enforcement Administration listed THJ-2201 as Schedule I in January 2015.

Protein glycosylation is increasingly recognized as a crucial modulator of protein function, offering a third layer of biological information over genomics and proteomics. Modern tools for analyzing released N-glycans from cells and body fluids, i.e., the glycome, have shown abnormal protein glycosylation in numerous human diseases. These include both genetic and acquired diseases, ranging from diabetes, cancer, and inflammatory disease to neurodegenerative and neuromuscular disease. Insights from this novel field in human medicine provide exciting perspectives toward understanding disease processes, identifying therapeutic targets, and designing individualized diagnostics based on protein concentrations and glycosylation status. However, the main question is how we can translate this information into concrete biomarkers in a clinical diagnostic setting, with high demands on technical robustness and the ability to interpret results within specific patient groups.

The Kidney Disease Improving Global Outcomes (KDIGO) guideline recommends use of a cystatin C–based estimated glomerular filtration rate (eGFR) to confirm creatinine-based eGFR between 45 and 59 mL · min−1 · (1.73 m2)−1. Prior studies have demonstrated that comorbidities such as solid-organ transplant strongly influence the relationship between measured GFR, creatinine, and cystatin C. Our objective was to evaluate the performance of cystatin C–based eGFR equations compared with creatinine-based eGFR and measured GFR across different clinical presentations.

Informatics is changing the processes behind laboratory medicine. With ever-growing demands on laboratory medicine professionals not only to collect and interpret omics data in the era of the Precision Medicine Initiative, but also to ensure high-quality, low-cost patient management in the structure of accountable care organizations, we have invited several experts to discuss their take on "big data."

Combined testing of high-sensitivity cardiac troponin T (hs-cTnT) and copeptin at presentation provides a very high—although still imperfect—negative predictive value (NPV) for the early rule-out of acute myocardial infarction (AMI). We hypothesized that a second copeptin measurement at 1 h might further increase the NPV.

We investigated whether obese pregnant women negative for gestational diabetes (GDM) still experience dysglycemia, as indicated by high glycated hemoglobin (Hb A1c) at delivery, and whether this impacts offspring and long-term maternal outcomes.

STARD 2015: An updated list of essential items for reporting diagnostic accuracy studies

Increased concentrations of non-fasting remnant cholesterol are thought to be atherogenic in thesame way as LDL cholesterol,by transport into andaccumulationof lipid into the arterial wall.

For patients with acute coronary syndrome who have undergone interventions such as placement of a stent, it has become standard practice to treat them with a combination of aspirin and opidogrel to prevent subsequent thrombotic events; however, clopidogrel is a drug that requires activation by a liver enzyme, CYP2C19.

Most of us are familiar with the link between elevated concentrations of lipids in our blood and an increased risk for cardiovascular disease which is responsible for about 500,000 deaths each year in the United States. It has been common practice to measure those lipids only after a period of fasting. This practice was put in place because of the known increases in triglycerides that can occur after eating; however, fasting lipid profiles have not actually been shown to be superior to nonfasting lipid profiles in assessing the risk for cardiovascular disease.

Microfluidics has attracted a lot of attention across a wide range of disciplines because of the potential for using it to analyze tiny samples and to integrate processes onto handheld Labs-on-a-Chip. So instead of sending vials of blood to a central laboratory and getting results back days later, you can imagine a Microfluidic device that can give you the same performance, but with a finger prick of blood right on the spot, in minutes.

Commutability is an important concept in determining traceability and relationship among different methods used to measure the same analyte, but how to delineate commutable materials is not straightforward and a number of techniques have been proposed.

Several studies have suggested that prevention of atherosclerosis should begin in childhood as dyslipidemia in children is associated with severity of atherosclerotic lesions later in life. Pediatric lipid screening aims to identify children and adolescents with dyslipidemia, including both those with more severe genetic cases and those cases with mild to moderate lipid elevation due to secondary causes.