A novel immunoprecipitation-based targeted liquid chromatography-tandem mass spectrometry analysis for accurate determination for copeptin in human serum.

Objectives: Copeptin, a stable and simple-to-measure surrogate marker for arginine vasopressin (AVP), demonstrates excellent clinical values, particularly in diagnosing polyuria-polydipsia syndromes. However, conventional immunoassay methods are limited and lack comparability. Our aim was to establish a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying copeptin in human serum.

Comparative evaluation of four new immunoassays and LC-MS/MS for the measurement of urinary free cortisol in Cushing's syndrome diagnosis.

Objectives: Twenty-four-hour urinary free cortisol (UFC) measurement is the initial diagnostic test for Cushing's syndrome (CS). We compared UFC determination by four new immunoassays using Autobio A6200, Mindray CL-1200i, Snibe MAGLUMI X8 and Roche 8000 e801 with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Additionally, we evaluated the value of 24-h UFC measured by four direct immunoassays for diagnosing CS.

Cardiac troponin.

Cardiac troponin (cTn) testing plays a crucial role in the diagnosis of cardiovascular diseases, particularly acute coronary syndrome (ACS), which includes acute myocardial infarction (AMI). However, conventional immunoassays may be subject to interference from autoantibodies, cross-reactivity, and biotin-related effects, compromising diagnostic accuracy. A thorough investigation of these interference mechanisms is necessary to improve assay methodologies, ensuring greater reliability and precision.

From interference to insight: pseudo-lipidemia led to the diagnosis of Waldenström macroglobulinemia.

Waldenström macroglobulinemia (WM) is a rare hematological disorder with an annual incidence of about 3 per million. Its clinical manifestations are diverse and non - specific, and approximately 30% of patients are asymptomatic, making early diagnosis challenging. This paper reports a 73-year-old female who was admitted to the hospital due to atrial fibrillation.

Advances in laboratory diagnosis of Sjogren's disease in children.

Sjogren's disease (SjD) in children is a rare chronic autoimmune disease not fully recognized due to clinical manifestations different from adults. As such, new objective indicators are needed to supplement existing markers and assist in diagnosis. This review summarizes pathogenesis of SjD in children, current diagnostic criteria and research progress in laboratory diagnosis including serologic testing, saliva and tear analysis, histopathological examination as well as emerging markers of interest.

CSF and blood glial fibrillary acidic protein for the diagnosis of Alzheimer's disease: A systematic review and meta-analysis.

Recently included in the 2024 new revised diagnostic criteria of Alzheimer's disease (AD), glial fibrillary acidic protein (GFAP) has garnered significant attention. A systematic review and meta-analysis were performed to comprehensively evaluate the diagnostic, differential diagnostic, and prospective diagnostic performance of GFAP in cerebrospinal fluid (CSF) and blood for AD continuum. A literature search using common electronic databases, important websites and historical search way was performed from inception to the beginning of March 2023.

Liquid chromatography-tandem mass spectrometry in clinical laboratory protein measurement.

Proteins are essential components of human cells and tissues, and they are commonly measured in clinical laboratories using immunoassays. However, these assays have certain limitations, such as non-specificity binding, insufficient selectivity, and interference of antibodies. More sensitive, accurate, and efficient technology is required to overcome these limitations.

Plasma Steroid Profiling Combined With Machine Learning for the Differential Diagnosis in Mild Autonomous Cortisol Secretion From Nonfunctioning Adenoma in Patients With Adrenal Incidentalomas.

Objective: To assess the diagnostic value of combining plasma steroid profiling with machine learning (ML) in differentiating between mild autonomous cortisol secretion (MACS) and nonfunctioning adenoma (NFA) in patients with adrenal incidentalomas.

Methods: The plasma steroid profiles data in the laboratory information system were screened from January 2021 to December 2023. EXtreme Gradient Boosting was applied to establish diagnostic models using plasma 24-steroid panels and/or clinical characteristics of the subjects.

Evolution of LC-MS/MS in clinical laboratories.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has attracted significant attention in clinical practice owing to its numerous advantages. However, the widespread adoption of this technique is hindered by certain limitations, such as inappropriate analyte selection, low levels of automation, and a lack of specific reference intervals and quality control programs. This review comprehensively summarizes the current challenges associated with LC-MS/MS and proposes potential resolutions.

Steroid profiling in adrenal disease.

The measurement of steroid hormones in blood and urine, which reflects steroid biosynthesis and metabolism, has been recognized as a valuable tool for identifying and distinguishing steroidogenic disorders. The application of mass spectrometry enables the reliable and simultaneous analysis of large panels of steroids, ushering in a new era for diagnosing adrenal diseases. However, the interpretation of complex hormone results necessitates the expertise and experience of skilled clinicians.

Comparison of Direct and Extraction Immunoassay Methods With Liquid Chromatography-Tandem Mass Spectrometry Measurement of Urinary Free Cortisol for the Diagnosis of Cushing's Syndrome.

Background: Twenty-four-hour urinary free cortisol (UFC) measurement is the initial diagnostic test for Cushing's syndrome (CS). We compared UFC determination by both direct and extraction immunoassays using Abbott Architect, Siemens Atellica Solution, and Beckman DxI800 with liquid chromatography-tandem mass spectrometry (LC-MS/MS). In addition, we evaluated the value of 24-hr UFC measured by six methods for diagnosing CS.

Establishment of a reference interval for total carbon dioxide using indirect methods in Chinese populations living in high-altitude areas: A retrospective real-world analysis.

Background: Hypoxia leads to different concentrations of the bicarbonate buffer system in Tibetan people. Indirect methods were used to establish the reference interval (RI) for total carbon dioxide (tCO2) based on big data from the adult population of Tibet, a high-altitude area in Western China.

Methods: Anonymous tCO2 test data (n = 442,714) were collected from the People's Hospital of the Tibet Autonomous Region from January 2018, to December 2021.

Liquid chromatography-tandem mass spectrometry in fat-soluble vitamin deficiency.

Fat-soluble vitamins, including vitamins A, D, E, and K, are essential for maintaining normal body function and metabolism. Fat-soluble vitamin deficiency may lead to bone diseases, anemia, bleeding, xerophthalmia, etc. Early detection and timely interventions are significant for preventing vitamin deficiency-related diseases.

Diagnostic Accuracy of Copeptin in the Differential Diagnosis of Patients With Diabetes Insipidus: A Systematic Review and Meta-analysis.

Objective: Accurate diagnosis of diabetes insipidus (DI) is of significant importance for correct management. We aimed to evaluate the diagnostic accuracy of copeptin level measurements in the differential diagnosis between DI and primary polydipsia (PP).

Methods: A literature search of electronic databases from January 1, 2005, to July 13, 2022, was performed.

Novel Magnetic-Bead-Assisted Sequential Extraction Method for Liquid Chromatography-Mass Spectrometry (MS)/MS of Components with Diverse Properties: Gastrin Determination as a Case Study.

Sample preparation is the rate-limiting step in liquid chromatography-mass spectrometry (LC-MS)/MS-based clinical analysis when target analytes possess significantly different properties. Repeated solid-phase extraction (SPE) processes are typically required, resulting in low throughput and excessive consumption of labor, materials, and samples. In this study, we developed and validated a feasible and productive method to enrich target analytes with different properties during a single operation, while sufficiently removing matrix interferences to meet LC-MS/MS requirements.

Preanalytical considerations in parathyroid hormone measurement.

Automated immunoassays used to evaluate parathyroid function are vulnerable to different types of interference, which can affect clinical practices. This review provides a detailed overview of the six main types of interference known to affect the measurement of parathyroid hormone (PTH): heterophilic antibodies, biotin, PTH fragments, oxidized PTH (oxPTH), phosphorylated PTH, and some preanalytical factors. Because the prevalence of some of these conditions has been reported to approach 11.

How far is the goal of applying β-amyloid in cerebrospinal fluid for clinical diagnosis of Alzheimer's disease with standardization of measurements?

Cerebrospinal fluid (CSF) β-amyloid (Aβ) is important for early diagnosis of Alzheimer's disease (AD). However, the cohort distributions and cut-off values have large variation across different analytical assays, kits, and laboratories. In this review, we summarize the cut-off values and diagnostic performance for CSF Aβ1-42 and Aβ1-42/Aβ1-40, and explore the important effect factors.

High Thyrotropin Levels and Risk of Mortality in the Elderly With Subclinical Hypothyroidism: A Systematic Review and Meta-analysis.

Objective: This study aims to determine whether elevated endogenous thyrotropin levels contribute to an increased risk of adverse outcomes, such as all-cause mortality in older adults with subclinical hypothyroidism.

Methods: Eight electronic databases were searched for relevant articles from inception until March 23, 2022. Cohort studies assessing the association between thyrotropin levels and the risk of mortality among older adults aged ≥60 years with subclinical hypothyroidism were eligible.

Copeptin with high-sensitivity cardiac troponin to rule out non-ST-elevation myocardial infarction early on: A systematic review and meta-analysis.

High-sensitivity cardiac troponin (hs-cTn) with copeptin in rapidly ruling out non-ST-elevation myocardial infarction (NSTEMI) remains controversial. We aimed to evaluate the diagnostic accuracy of this combination compared to hs-cTn alone. A literature search of electronic databases was performed from inception to 26 March 2022.

Review on the roles of specific cell-derived exosomes in Alzheimer's disease.

Alzheimer's disease (AD) is the sixth leading cause of death worldwide and cannot be effectively cured or prevented; thus, early diagnosis, and intervention are important. The importance of exosomes, membrane-bound extracellular vesicles produced in the endosome of eukaryotic cells, in the development, diagnosis, and treatment of AD has been recognized; however, their specific functions remain controversial and even unclear. With the development of exosome extraction, isolation, and characterization, many studies have focused on exosomes derived from different cells and body fluids.

Copeptin as a Diagnostic and Prognostic Biomarker in Cardiovascular Diseases.

Copeptin is the carboxyl-terminus of the arginine vasopressin (AVP) precursor peptide. The main physiological functions of AVP are fluid and osmotic balance, cardiovascular homeostasis, and regulation of endocrine stress response. Copeptin, which is released in an equimolar mode with AVP from the neurohypophysis, has emerged as a stable and simple-to-measure surrogate marker of AVP and has displayed enormous potential in clinical practice.

Copeptin in fluid disorders and stress.

Copeptin, a glycosylated peptide of 39 amino acids, is the C-terminal segment of arginine vasopressin (AVP) precursor peptide, which is consisted of two other fragments, vasopressin and neurophysin Ⅱ. The main physiological functions of AVP are fluid and osmotic balance, cardiovascular homeostasis and regulation of the endocrine stress response. Numerous studies have demonstrated that the endogenous AVP in plasma is a meaningful biomarker to guide diagnosis and therapy of diseases associated with fluids disorders and stress.