Critical reviews in clinical laboratory sciences最新文献

Recent changes in the regulatory assessment of in vitro medical tests reflect a growing recognition of the need for more stringent clinical evidence requirements to protect patient safety and health. Under current regulations in the United States and Europe, when needed for regulatory approval, clinical performance reports must provide clinical evidence tailored to the intended purpose of the test and allow assessment of whether the test will achieve the intended clinical benefit. The quality of evidence must be proportionate to the risk for the patient and/or public health. These requirements now cover both commercial and laboratory developed tests (LDT) and demand a sound understanding of the fundamentals of clinical performance measures and study design to develop and appraise the study plan and interpret the study results. However, there is a lack of harmonized guidance for the laboratory profession, industry, regulatory agencies and notified bodies on how the clinical performance of tests should be measured. The Working Group on Test Evaluation (WG-TE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) is a multidisciplinary group of laboratory professionals, clinical epidemiologists, health technology assessment experts, and representatives of the in vitro diagnostic (IVD) industry. This guidance paper aims to promote a shared understanding of the principles of clinical performance measures and study design. Measures of classification performance, also referred to as discrimination, such as sensitivity and specificity are firmly established as the primary measures for evaluating the clinical performance for screening and diagnostic tests. We explain these measures are just as relevant for other purposes of testing. We outline the importance of defining the most clinically meaningful classification of disease so the clinical benefits of testing can be explicitly inferred for those correctly classified, and harm for those incorrectly classified. We introduce the key principles and a checklist for formulating the research objective and study design to estimate clinical performance: (1) the purpose of a test e.g. diagnosis, screening, risk stratification, prognosis, prediction of treatment benefit, and corresponding research objective for assessing clinical performance; (2) the target condition for clinically meaningful classification; (3) clinical performance measures to assess whether the test is fit-for-purpose; and (4) study design types. Laboratory professionals, industry, and researchers can use this checklist to help identify relevant published studies and primary datasets, and to liaise with clinicians and methodologists when developing a study plan for evaluating clinical performance, where needed, to apply for regulatory approval.

Monitoring individuals' laboratory data is essential for assessing their health status, evaluating the effectiveness of treatments, predicting disease prognosis and detecting subclinical conditions. Currently, monitoring is performed intermittently, measuring serum, plasma, whole blood, urine and occasionally other body fluids at predefined time intervals. The ideal monitoring approach entails continuous measurement of concentration and activity of biomolecules in all body fluids, including solid tissues. This can be achieved through the use of biosensors strategically placed at various locations on the human body where measurements are required for monitoring. High-tech wearable biosensors provide an ideal, noninvasive, and esthetically pleasing solution for monitoring individuals' laboratory data. However, despite significant advances in wearable biosensor technology, the measurement capacities and the number of different analytes that are continuously monitored in patients are not yet at the desired level. In this review, we conducted a literature search and examined: (i) an overview of the background of monitoring for personalized laboratory medicine, (ii) the body fluids and analytes used for monitoring individuals, (iii) the different types of biosensors and methods used for measuring the concentration and activity of biomolecules, and (iv) the statistical algorithms used for personalized data analysis and interpretation in monitoring and evaluation.

Poor analytical quality may be the bane of medical use of laboratory tests, and the fight against excessive analytical variability presents a daily struggle. Laboratories should prioritize the perspectives and needs of their customers (the patients and healthcare personnel). Among them, comparability of results from the same patient sample when measured by different laboratories using different in vitro diagnostic (IVD) medical devices is a logical priority to avoid result misinterpretation and potential patient harm. Harmonization (standardization) of laboratory measurements can be achieved by establishing metrological traceability of the results on clinical samples to stated higher-order references and providing an estimate of the uncertainty of measurement (MU). This estimate should be based on an MU budget including all known MU contributions generated by the employed calibration hierarchy, which in turn should be validated against fit-for-purpose maximum allowable MU derived according to internationally recommended models. In this report, we review the available strategies for establishing, evaluating, and monitoring analytical quality, drawing on three decades experience in the field. We discuss the most important aspects that may influence obtaining and maintaining analytical standardization in laboratory medicine, and offer practical solutions aimed at educating all stakeholders for the achievement of harmonized laboratory results. To fully implement the recommended approaches, all involved parties-i.e. reference providers, IVD manufacturers, medical laboratories, and External Quality Assessment organizers-must agree on their importance and enhance their specific knowledge.

The journey of translating a molecular discovery into the clinic involves multiple steps and requires planning, time, effort, and money. In this review, we provide a quick guide on the technical and clinical validation parameters that are necessary for successful commercialization of molecular and other markers. We also briefly address the different options for regulatory approvals. Successful clinical implantation depends on rigorous technical and clinical validation, and the ability to develop clear guidelines for the indications for testing (i.e. which patients are eligible to have this test), the frequency of testing, and also a clear interpretation of test results. Successful implementation requires providing evidence that the results of this test can be used to improve patient care. There are currently multiple routes for implementation of clinical molecular tests, which include regulatory agency- approved companion diagnostics, laboratory developed tests, or direct-to-consumer testing. Regulatory approval is considered the gold-standard, but it requires time and resources. There is an ongoing debate about the need for regulatory approval of laboratory developed testing. Ongoing oversight is maintained through lab accreditation and proficiency testing programs, which provide a common approach to ensuring high standards and consistent performance in clinical molecular labs. Before moving into the clinic, confirmation of both the clinical and analytic validity of a new molecular test is essential.

We present a series of three articles on the genetics and pharmacogenetics of G protein- coupled receptors (GPCR). In the first article, we discuss genetic variants of the G protein subunits and accessory proteins that are associated with human phenotypes; in the second article, we build upon this to discuss "G protein-coupled receptor (GPCR) gene variants and human genetic disease" and in the third article, we survey "G protein-coupled receptor pharmacogenomics". In the present article, we review the processes of ligand binding, GPCR activation, inactivation, and receptor trafficking to the membrane in the context of human genetic disease resulting from pathogenic variants of accessory proteins and G proteins. Pathogenic variants of the genes encoding G protein α and β subunits are examined in diverse phenotypes. Variants in the genes encoding accessory proteins that modify or organize G protein coupling have been associated with disease; these include the contribution of variants of the regulator of G protein signaling (RGS) to hypertension; the role of variants of activator of G protein signaling type III in phenotypes such as hypoxia; the contribution of variation at the RGS10 gene to short stature and immunological compromise; and the involvement of variants of G protein-coupled receptor kinases (GRKs), such as GRK4, in hypertension. Variation in genes that encode proteins involved in GPCR signaling are outlined in the context of the changes in structure and function that may be associated with human phenotypes.

The study of metabolomics is revealing immense potential for diagnosis, therapy monitoring, and understanding of pathogenesis processes. Volatilomics is a subcategory of metabolomics interested in the detection of molecules that are small enough to be released in the gas phase. Volatile compounds produced by cellular processes are released into the blood and lymph, and can reach the external environment through different pathways, such as the blood-air interface in the lung that are detected in breath, or the blood-water interface in the kidney that leads to volatile compounds detected in urine. Besides breath and urine, additional sources of volatile compounds such as saliva, blood, feces, and skin are available. Volatilomics traces its roots back over fifty years to the pioneering investigations in the 1970s. Despite extensive research, the field remains in its infancy, hindered by a lack of standardization despite ample experimental evidence. The proliferation of analytical instrumentations, sample preparations and methods of volatilome sampling still make it difficult to compare results from different studies and to establish a common standard approach to volatilomics. This review aims to provide an overview of volatilomics' diagnostic potential, focusing on two key technical aspects: sampling and analysis. Sampling poses a challenge due to the susceptibility of human samples to contamination and confounding factors from various sources like the environment and lifestyle. The discussion then delves into targeted and untargeted approaches in volatilomics. Some case studies are presented to exemplify the results obtained so far. Finally, the review concludes with a discussion on the necessary steps to fully integrate volatilomics into clinical practice.

Immunoglobulin G (IgG) and immunoglobulin M (IgM) testing are commonly used to determine infection status. Typically, the detection of IgM indicates an acute or recent infection, while the presence of IgG alone suggests a chronic or past infection. However, relying solely on IgG and IgM antibody positivity may not be sufficient to differentiate acute from chronic infections. This limitation arises from several factors. The prolonged presence of IgM can complicate diagnostic interpretations, and false positive IgM results often arise from antibody cross-reactivity with various antigens. Additionally, IgM may remain undetectable in prematurely collected samples or in individuals who are immunocompromised, further complicating accurate diagnosis. As a result, additional diagnostic tools are required to confirm infection status. Avidity is a measure of the strength of the binding between an antigen and antibody. Avidity-based assays have been developed for various infectious agents, including toxoplasma, cytomegalovirus (CMV), SARS-CoV-2, and avian influenza, and are promising tools in clinical diagnostics. By measuring the strength of antibody binding, they offer critical insights into the maturity of the immune response. These assays are instrumental in distinguishing between acute and chronic or past infections, monitoring disease progression, and guiding treatment decisions. The development of automated platforms has optimized the testing process by enhancing efficiency and minimizing the risk of manual errors. Additionally, the recent advent of real-time biosensor immunoassays, including the label-free immunoassays (LFIA), has further amplified the capabilities of these assays. These advances have expanded the clinical applications of avidity-based assays, making them useful tools for the diagnosis and management of various infectious diseases. This review is structured around several key aspects of IgG avidity in clinical diagnosis, including: (i) a detailed exposition of the IgG affinity maturation process; (ii) a thorough discussion of the IgG avidity assays, including the recently emerged biosensor-based approaches; and (iii) an examination of the applications of IgG avidity in clinical diagnosis. This review is intended to contribute toward the development of enhanced diagnostic tools through critical assessment of the present landscape of avidity-based testing, which allows us to identify the existing knowledge gaps and highlight areas for future investigation.

The technique of Quantitative Fluorescence in Situ Hybridization (Q-FISH) plays a crucial role in determining the length of telomeres for studies in molecular biology and cytogenetics. Throughout the years, the use of Q-FISH for measuring telomere length has made substantial contributions to research in aging, cancer, and stem cells. The objective of this analysis is to delineate the categorization, fundamental concepts, pros and cons, and safety measures of Q-FISH in telomere length analysis, encapsulate, and anticipate its principal uses across diverse human biomedical research fields.

Polycystic ovary syndrome (PCOS) is a complex multifactorial endocrinopathy affecting reproductive aged women globally, whose presentation is strongly influenced by genetic makeup, ethnic, and geographic diversity leaving these affected women substantially predisposed to reproductive and metabolic perturbations. Sophisticated techniques spanning genomics, proteomics, epigenomics, and transcriptomics have been harnessed to comprehensively understand the enigmatic pathophysiology of PCOS, however, conclusive markers for PCOS are still lacking today. Metabolomics represents a paradigm shift in biotechnological advances enabling the simultaneous identification and quantification of metabolites and the use of this approach has added yet another dimension to help unravel the strong metabolic component of PCOS. Reports dissecting the metabolic signature of PCOS have revealed disparate levels of metabolites such as pyruvate, lactate, triglycerides, free fatty acids, carnitines, branched chain and essential amino acids, and steroid intermediates in major biological compartments. These metabolites have been shown to be altered in women with PCOS overall, after phenotypic subgrouping, in animal models of PCOS, and also following therapeutic intervention. This review seeks to supplement previous reviews by highlighting the aforementioned aspects and to provide easy, coherent and elementary access to significant findings and emerging trends. This will in turn help to delineate the metabolic plot in women with PCOS in various biological compartments including plasma, urine, follicular microenvironment, and gut. This may pave the way to design additional studies on the quest of unraveling the etiology of PCOS and delving into novel biomarkers for its diagnosis, prognosis and management.