Laboratory Detection and Initial Diagnosis of Monoclonal Gammopathies.

Context.—: The process for identifying patients with monoclonal gammopathies is complex. Initial detection of a monoclonal immunoglobulin protein (M protein) in the serum or urine often requires compilation of analytical data from several areas of the laboratory.

Single-Dilution COVID-19 Antibody Test with Qualitative and Quantitative Readouts.

The coronavirus disease 2019 (COVID-19) global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to place an immense burden on societies and health care systems. A key component of COVID-19 control efforts is serological testing to determine the community prevalence of SARS-CoV-2 exposure and quantify individual immune responses to prior SARS-CoV-2 infection or vaccination. Here, we describe a laboratory-developed antibody test that uses readily available research-grade reagents to detect SARS-CoV-2 exposure in patient blood samples with high sensitivity and specificity.

Standardization of Free Thyroxine Measurements Allows the Adoption of a More Uniform Reference Interval.

Background: The IFCC Committee for Standardization of Thyroid Function Tests intended to standardize free thyroxine (FT) immunoassays. We developed a Système International d'Unités traceable conventional reference measurement procedure (RMP) based on equilibrium dialysis and mass spectrometry. We describe here the latest studies intended to recalibrate against the RMP and supply a proof of concept, which should allow continued standardization efforts.

Harmonization of Serum Thyroid-Stimulating Hormone Measurements Paves the Way for the Adoption of a More Uniform Reference Interval.

Background: The IFCC Committee for Standardization of Thyroid Function Tests developed a global harmonization approach for thyroid-stimulating hormone measurements. It is based on a multiassay method comparison study with clinical serum samples and target setting with a robust factor analysis method. Here we describe the Phase IV method comparison and reference interval (RI) studies conducted with the objective to recalibrate the participating assays and demonstrate the proof-of-concept.

Prevalence of Traditional and Reverse-Algorithm Syphilis Screening in Laboratory Practice: A Survey of Participants in the College of American Pathologists Syphilis Serology Proficiency Testing Program.

Context: -Syphilis serology screening in laboratory practice is evolving. Traditionally, the syphilis screening algorithm begins with a nontreponemal immunoassay, which is manually performed by a laboratory technologist. In contrast, the reverse algorithm begins with a treponemal immunoassay, which can be automated.

Progress in standardizing and harmonizing thyroid function tests.

Iodine is an essential component of thyroid hormone. Because thyroid hormone synthesis is affected by iodine deficiency on the one hand and by excess iodine intake on the other, thyroid function biomarkers may be useful for assessing iodine status and studying the effects of iodine supplementation. However, reference intervals for some of the most useful thyroid function biomarkers, including serum concentrations of thyroid-stimulating hormone (TSH), free thyroxine (FT4), and thyroglobulin, vary widely due to variability in the commercially available immunoassays for these tests.

Standardization of FT4 and harmonization of TSH measurements - a request for input from endocrinologists and other physicians.

Given the prevalence of thyroid disorders and the subtle signs and symptoms that may accompany subclinical disease, reliable laboratory testing for serum TSH and free thyroid hormones is important for both primary care physicians and endocrinologists. The laboratory community has recognized the need for standardization of thyroid function tests to achieve comparability of measurement results between methods. This applies in particular to tests for free T4 (FT4), which may be considered controversial in terms of clinical and analytical validity.

Rapid measurement of tacrolimus in whole blood by paper spray-tandem mass spectrometry (PS-MS/MS).

Background: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) provides sensitivity and specificity for monitoring tacrolimus drug level in blood, but it requires an LC system and sample preparation, which is not amenable to random access testing typical of immunoassays. Paper spray (PS) ionization generates gas phase analyte ions directly from dried blood spots without sample preparation and LC. We evaluated a PS-MS/MS method for tacrolimus drug monitoring in a clinical diagnostic laboratory.

A Progress Report of the IFCC Committee for Standardization of Thyroid Function Tests.

Background: The IFCC Committee for Standardization of Thyroid Function Tests aims at equivalence of laboratory test results for free thyroxine (FT4) and thyrotropin (TSH).

Objectives: This report describes the phase III method comparison study with clinical samples representing a broad spectrum of thyroid disease. The objective was to expand the feasibility work and explore the impact of standardization/harmonization in the clinically relevant concentration range.

Principles and pitfalls of free hormone measurements.

The free hormone hypothesis states that a hormone's physiological effects depend on the free hormone concentration, not the total hormone concentration. Although the in vivo relationship between free hormone and protein-bound hormone is complex, most experts have applied this view to the design of assays used to assess the free hormone concentration in the blood sampled for testing in vitro. The history of the measurement of free thyroxine, probably the most frequently requested free hormone determination, offers a good example of the approaches that have been taken.

Biomarkers of sepsis.

Sepsis is an unusual systemic reaction to what is sometimes an otherwise ordinary infection, and it probably represents a pattern of response by the immune system to injury. A hyper-inflammatory response is followed by an immunosuppressive phase during which multiple organ dysfunction is present and the patient is susceptible to nosocomial infection. Biomarkers to diagnose sepsis may allow early intervention which, although primarily supportive, can reduce the risk of death.

Established and novel biomarkers of sepsis.

The increased incidence of sepsis, a systemic response to infection that occurs in some patients, has stimulated interest in identifying infected patients who are at risk and intervening early. When this condition progresses to severe sepsis (characterized by organ dysfunction), mortality is high. Hospitals that have implemented recommendations of the Surviving Sepsis Campaign have seen a reduction in mortality rate for hospital-acquired severe sepsis.

Vancomycin plasma concentrations in cardiac surgery with the use of profound hypothermic circulatory arrest.

Objective: This study was undertaken to compare the effect of deep hypothermic circulatory arrest, compared with moderate hypothermia, on the plasma concentrations and pharmacokinetic profile of vancomycin, administered as prophylaxis, in patients undergoing cardiac surgery with cardiopulmonary bypass.

Methods: Two groups of adult cardiac surgery patients were prospectively studied. One group consisted of 12 patients undergoing valvular surgery with moderate hypothermia, and another group was of 12 patients undergoing surgery with the use of profound hypothermic circulatory arrest.