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1.
Clin Chem Lab Med ; 61(10): 1708-1718, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37021544

RESUMO

OBJECTIVES: Knowledge of the stability of analytes in clinical specimens is a prerequisite for proper transport and preservation of samples to avoid laboratory errors. The new version of ISO 15189:2022 and the European directive 2017/746 increase the requirements on this topic for manufacturers and laboratories. Within the project to generate a stability database of European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group Preanalytical Phase (WG-PRE), the need to standardise and improve the quality of published stability studies has been detected, being a manifest deficit the absence of international guidelines for the performance of stability studies on clinical specimens. METHODS: These recommendations have been developed and summarised by consensus of the WG-PRE and are intended primarily to improve the quality of sample stability claims included in information for users provided by assay supplier companies, according to the requirements of the new European regulations and standards for accreditation. RESULTS: This document provides general recommendations for the performance of stability studies, oriented to the estimation of instability equations in the usual working conditions, allowing flexible adaptation of the maximum permissible error specifications to obtain stability limits adapted to the intended use. CONCLUSIONS: We present this recommendation based on the opinions of the EFLM WG-PRE group for the standardisation and improvement of stability studies, with the intention to improve the quality of the studies and the transferability of their results to laboratories.


Assuntos
Química Clínica , Fase Pré-Analítica , Humanos , Laboratórios , Padrões de Referência , Acreditação
2.
Clin Chem Lab Med ; 2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-35258235

RESUMO

Since the beginning of laboratory medicine, the main focus was to provide high quality analytics. Over time the importance of the extra-analytical phases and their contribution to the overall quality became evident. However, as the initial preanalytical processes take place outside of the laboratory and mostly without its supervision, all professions participating in these process steps, from test selection to sample collection and transport, need to engage accordingly. Focusing solely on intra-laboratory processes will not be sufficient to achieve the best possible preanalytical quality. The Working Group for the Preanalytical Phase (WG-PRE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has provided several recommendations, opinion papers and scientific evidence over the past years, aiming to standardize the preanalytical phase across Europe. One of its strategies to reach this goal are educational efforts. As such, the WG-PRE has organized five conferences in the past decade with the sole focus on preanalytical quality. This year's conference mainly aims to depict the views of different professions on preanalytical processes in order to acquire common ground as basis for further improvements. This article summarizes the content of this 6th preanalytical conference.

3.
Clin Chem ; 67(7): 1008-1018, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34136904

RESUMO

BACKGROUND: Conventional HER2-targeting therapies improve outcomes for patients with HER2-positive breast cancer (BC), defined as tumors showing HER2 protein overexpression by immunohistochemistry and/or ERBB2 gene amplification determined by in situ hybridization (ISH). Emerging HER2-targeting compounds show benefit in some patients with neither HER2 protein overexpression nor ERBB2 gene amplification, creating a need for new assays to select HER2-low tumors for treatment with these compounds. We evaluated the analytical performance of a targeted mass spectrometry-based assay for quantifying HER2 protein in formalin-fixed paraffin-embedded (FFPE) and frozen BC biopsies. METHODS: We used immunoaffinity-enrichment coupled to multiple reaction monitoring-mass spectrometry (immuno-MRM-MS) to quantify HER2 protein (as peptide GLQSLPTHDPSPLQR) in 96 frozen and 119 FFPE BC biopsies. We characterized linearity, lower limit of quantification (LLOQ), and intra- and inter-day variation of the assay in frozen and FFPE tissue matrices. We determined concordance between HER2 immuno-MRM-MS and predicate immunohistochemistry and ISH assays and examined the benefit of multiplexing the assay to include proteins expressed in tumor subcompartments (e.g., stroma, adipose, lymphocytes, epithelium) to account for tissue heterogeneity. RESULTS: HER2 immuno-MRM-MS assay linearity was ≥103, assay coefficient of variation was 7.8% (FFPE) and 5.9% (frozen) for spiked-in analyte, and 7.7% (FFPE) and 7.9% (frozen) for endogenous measurements. Immuno-MRM-MS-based HER2 measurements strongly correlated with predicate assay HER2 determinations, and concordance was improved by normalizing to glyceraldehyde-3-phosphate dehydrogenase. HER2 was quantified above the LLOQ in all tumors. CONCLUSIONS: Immuno-MRM-MS can be used to quantify HER2 in FFPE and frozen BC biopsies, even at low HER2 expression levels.


Assuntos
Neoplasias da Mama , Biomarcadores Tumorais/genética , Neoplasias da Mama/patologia , Feminino , Formaldeído/química , Humanos , Espectrometria de Massas/métodos , Inclusão em Parafina , Receptor ErbB-2/análise , Fixação de Tecidos/métodos
4.
Ther Drug Monit ; 43(1): 25-34, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33315761

RESUMO

BACKGROUND: The opioid crisis has had a substantial financial impact on the health care system in the United States. This study evaluates how health plans have been affected financially and shows how a laboratory benefit management (LBM) program can be used to address related drug testing in an outpatient setting. METHODS: Monthly claims data from private health plans were collected from June 1, 2016 to February 29, 2020. The total number of claims (units) for definitive and presumptive drug testing were calculated and the number of paid claims recorded. Claims distribution by laboratory type and medical code billed, the paid rate and compound annual growth rate, and the test distribution and paid rate of rendering providers who had submitted a minimum of 1000 claims were determined. RESULTS: In total, 2,004,230 drug testing claims were submitted. After the LBM program was implemented, the percentage of paid claims for definitive drug testing (Healthcare Common Procedure Coding System code G0483) decreased and the paid rate for the low-cost tests (HCPCS code G0480) in physician office and independent laboratory settings increased. The compound annual growth rate for G0483 claims submitted indicated a 70.5% and 31.9% decrease in payments to physician offices and independent laboratories, respectively, for the period ending February 2020. CONCLUSIONS: An LBM program can positively address policy enforcement while reducing unnecessarily complex tests and limiting potential fraud, waste, and abuse by directing testing toward laboratories amenable to cost-efficient contractual savings. Moreover, for definitive drug testing, the enforcement of the use of Healthcare Common Procedure Coding System codes and a move toward more cost-efficient tests (G0480), when clinically applicable, supported by clinical practice guidelines, or evidence-based medicine, is an approach to providing medical benefits while maintaining health costs.


Assuntos
Seguro , Epidemia de Opioides , Detecção do Abuso de Substâncias/economia , Analgésicos Opioides , Custos de Cuidados de Saúde , Humanos , Estados Unidos/epidemiologia
5.
Crit Rev Clin Lab Sci ; 57(1): 1-21, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31603708

RESUMO

Hemolysis is conventionally defined as membrane disruption of red blood cells and other blood cells that is accompanied by subsequent release of intracellular components into the serum or plasma. It accounts for over 60% of blood sample rejections in the laboratory and is the most common preanalytical error in laboratory medicine. Hemolysis can occur both in vivo and in vitro. Intravascular hemolysis (in vivo) is always associated with an underlying pathological condition or disease, and thus careful steps should always be taken by the laboratory to exclude in vivo hemolysis with confidence. In vitro hemolysis, on the other hand, is highly preventable. It may occur at all stages of the preanalytical phase (i.e. sample collection, transport, handling and storage), and may lead to clinically relevant, yet spurious, changes in patient results by interfering with laboratory measurements. Hemolysis interference is exerted through several mechanisms: (1) spectrophotometric interference, (2) release of intracellular components, (3) sample dilution and (4) chemical interference. The degree of interference observed depends on the level of hemolysis and also on the assay methodology. Recent evidence shows that preanalytical practices related to detection and management of hemolyzed samples are highly heterogeneous and need to be standardized. The Working Group for Preanalytical Phase (WG-PRE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has published many recommendations for facilitating standardization and improvement of this important preanalytical issue. Some key EFLM WG-PRE publications related to hemolysis involve: (i) a call for more transparency and some practical recommendations for improving the harmonization of the automatic assessment of serum indices and their clinical usefulness, specifically the hemolysis index (H-index), (ii) recommendations on how to manage local quality assurance of serum or plasma hemolysis/icterus/lipemia-indices (HIL-indices) and (iii) recommendations on how to detect and manage hemolyzed samples in clinical chemistry testing. In this review we provide a comprehensive overview of hemolysis, including its causes and effects on clinical laboratory assays. Furthermore, we list and discuss the most recent recommendations aimed at managing hemolyzed samples in everyday practice. Given the high prevalence of hemolyzed blood samples, the associated costs, the great heterogeneity in how hemolysis is handled across healthcare settings, countries and continents, and increasing patient cross-border mobility, standardization and quality improvement processes aimed at combatting this important preanalytical problem are clearly warranted.


Assuntos
Análise Química do Sangue/normas , Coleta de Amostras Sanguíneas/normas , Hemólise , Automação Laboratorial/normas , Serviços de Laboratório Clínico , Humanos
6.
Clin Chem Lab Med ; 59(1): 59-69, 2020 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-32710715

RESUMO

To ensure that clinical laboratories produce results that are both accurate and of clinical utility it is essential that only samples of adequate quality are analysed. Although various studies and databases assessing the stability of analytes in different settings do exist, guidance on how to perform and report stability studies is lacking. This results in studies that often do not report essential information, thus compromising transferability of the data. The aim of this manuscript is to describe the Checklist for Reporting Stability Studies (CRESS) against which future studies should be reported to ensure standardisation of reporting and easy assessment of transferability of studies to other healthcare settings. The EFLM WG-PRE (European Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Preanalytical Phase) produced the CRESS checklist following a detailed literature review and extensive discussions resulting in consensus agreement. The checklist consists of 20 items covering all the aspects that should be considered when producing a report on a stability study including details of what should be included for each item and a rationale as to why. Adherence to the CRESS checklist will ensure that studies are reported in a transparent and replicable way. This will allow other laboratories to assess whether published data meet the stability criteria required in their own particular healthcare scenario. The EFLM WG-PRE encourage researchers and authors to use the CRESS checklist as a guide to planning stability studies and to produce standardised reporting of future stability studies.


Assuntos
Lista de Checagem , Publicações/normas , Relatório de Pesquisa/normas , Análise Química do Sangue/normas , Química Clínica/normas , Humanos , Fase Pré-Analítica/normas , Manejo de Espécimes/normas
7.
Artigo em Inglês | MEDLINE | ID: mdl-32228745

RESUMO

OBJECTIVES: We designed, developed, and implemented a new hospital-based health technology assessment (HB-HTA) program called Smart Innovation. Smart Innovation is a decision framework that reviews and makes technology adoption decisions. Smart Innovation was meant to replace the fragmented and complex process of procurement and adoption decisions at our institution. Because use of new medical technologies accounts for approximately 50 percent of the growth in healthcare spending, hospitals and integrated delivery systems are working to develop better processes and methods to sharpen their approach to adoption and management of high cost medical innovations. METHODS: The program has streamlined the decision-making process and added a robust evidence review for new medical technologies, aiming to balance efficiency with rigorous evidence standards. To promote system-wide adoption, the program engaged a broad representation of leaders, physicians, and administrators to gain support. RESULTS: To date, Smart Innovation has conducted eleven HB-HTAs and made clinician-led adoption decisions that have resulted in over $5 million dollars in cost avoidance. These are comprised of five laboratory tests, three software-assisted systems, two surgical devices, and one capital purchase. CONCLUSIONS: Smart Innovation has achieved cost savings, avoided uncertain or low-value technologies, and assisted in the implementation of new technologies that have strong evidence. The keys to its success have been the program's collaborative and efficient decision-making systems, partnerships with clinicians, executive support, and proactive role with vendors.


Assuntos
Prestação Integrada de Cuidados de Saúde/organização & administração , Avaliação da Tecnologia Biomédica/organização & administração , Redução de Custos , Prestação Integrada de Cuidados de Saúde/economia , Eficiência Organizacional , Humanos , Liderança , Uso Excessivo dos Serviços de Saúde/prevenção & controle
8.
Cell Tissue Bank ; 21(1): 89-97, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31838727

RESUMO

Precision tissue diagnostics rely on high quality input specimens so that assay results are not affected by artifact, but advances in collection and processing of tissue specimens have lagged behind innovations in diagnostic assay development. Therefore, we have designed and evaluated a novel surgical tissue collection device that maintains and monitors sample temperature and motion throughout transport so that the major preanalytical variable of tissue temperature can be controlled and measured. This device, in combination with an improved cold-hot tissue fixation protocol affords optimal biomarker preservation in less overall time, thereby simultaneously improving diagnostic quality and turnaround time. We collected 50 primary and metastatic liver tumors using a novel transport device. Tissue was fixed using a rapid cold-hot fixation protocol and immunohistochemical assays were used to assess the performance of the device, in comparison to control tissue preserved using standard clinical fixation protocol. Two pathologists evaluated the IHC studies in a blinded fashion to determine the immunophenotype of each tumor. The observed IHC staining intensities and the clinical impressions of the immunophenotypes did not differ between tissue collected with the novel device and control tissue, while improvements in processing time were achieved. The novel cold transport device and rapid fixation protocol can be successfully and safely combined and used to monitor specimen conditions, thus preserving the diagnostic utility of specimens and improving the overall turn-around time of the diagnostic process.


Assuntos
Biomarcadores Tumorais/análise , Biópsia/instrumentação , Neoplasias/patologia , Fixação de Tecidos/instrumentação , Preservação de Tecido/instrumentação , Biópsia/economia , Temperatura Baixa , Desenho de Equipamento , Humanos , Imuno-Histoquímica , Temperatura , Fatores de Tempo , Fixação de Tecidos/economia , Preservação de Tecido/economia
9.
JAMA ; 331(16): 1418-1419, 2024 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-38557893
10.
Clin Chem Lab Med ; 55(4): 489-500, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28231060

RESUMO

It is now undeniable that laboratory testing is vital for the diagnosis, prognostication and therapeutic monitoring of human disease. Despite the many advances made for achieving a high degree of quality and safety in the analytical part of diagnostic testing, many hurdles in the total testing process remain, especially in the preanalytical phase ranging from test ordering to obtaining and managing the biological specimens. The Working Group for the Preanalytical Phase (WG-PRE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has planned many activities aimed at mitigating the vulnerability of the preanalytical phase, including the organization of three European meetings in the past 7 years. Hence, this collective article follows the previous three opinion papers that were published by the EFLM WGPRE on the same topic, and brings together the summaries of the presentations that will be given at the 4th EFLM-BD meeting "Improving quality in the preanalytical phase through innovation" in Amsterdam, 24-25 March, 2017.


Assuntos
Coleta de Amostras Sanguíneas/normas , Química Clínica , Técnicas de Laboratório Clínico , Melhoria de Qualidade , Química Clínica/normas , Serviços de Laboratório Clínico/organização & administração , Técnicas de Laboratório Clínico/normas , Congressos como Assunto , Europa (Continente) , Hospitais , Humanos , Invenções , Inovação Organizacional , Flebotomia/métodos , Flebotomia/normas , Sociedades Médicas , Testes de Função Tireóidea/métodos , Testes de Função Tireóidea/normas
11.
J Proteome Res ; 15(8): 2717-28, 2016 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-27462933

RESUMO

Despite a clinical, economic, and regulatory imperative to develop companion diagnostics, precious few new biomarkers have been successfully translated into clinical use, due in part to inadequate protein assay technologies to support large-scale testing of hundreds of candidate biomarkers in formalin-fixed paraffin-embedded (FFPE) tissues. Although the feasibility of using targeted, multiple reaction monitoring mass spectrometry (MRM-MS) for quantitative analyses of FFPE tissues has been demonstrated, protocols have not been systematically optimized for robust quantification across a large number of analytes, nor has the performance of peptide immuno-MRM been evaluated. To address this gap, we used a test battery approach coupled to MRM-MS with the addition of stable isotope-labeled standard peptides (targeting 512 analytes) to quantitatively evaluate the performance of three extraction protocols in combination with three trypsin digestion protocols (i.e., nine processes). A process based on RapiGest buffer extraction and urea-based digestion was identified to enable similar quantitation results from FFPE and frozen tissues. Using the optimized protocols for MRM-based analysis of FFPE tissues, median precision was 11.4% (across 249 analytes). There was excellent correlation between measurements made on matched FFPE and frozen tissues, both for direct MRM analysis (R(2) = 0.94) and immuno-MRM (R(2) = 0.89). The optimized process enables highly reproducible, multiplex, standardizable, quantitative MRM in archival tissue specimens.


Assuntos
Células/química , Proteômica/métodos , Biomarcadores/análise , Formaldeído , Humanos , Marcação por Isótopo , Espectrometria de Massas/métodos , Inclusão em Parafina , Fixação de Tecidos , Preservação de Tecido/métodos
12.
Clin Chem ; 62(7): 973-81, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27197676

RESUMO

BACKGROUND: The CDC states that laboratory testing for persons under investigation for Ebola virus disease can be safely performed using automated laboratory instruments by adhering to bloodborne pathogen practices. We therefore sought to investigate the levels of viral contamination of a total laboratory automation (TLA) system to guide risk mitigation strategies for handling infectious agents. METHODS: Environmental swabs followed by PCR for hepatitis B (HBV) and hepatitis C (HCV) viruses were taken from a chemistry TLA system during routine clinical use and after running a small number of high-titer HCV samples. Control experiments were performed to ensure the recovery of DNA and RNA viruses by swabs from a representative nonporous surface. RESULTS: Of 79 baseline swabs for nucleic acids performed on the TLA system, 10 were positive for HBV and 8 for HCV. Viral nucleic acid was consistently detected from swabs taken from the distal inside surface of the decapper discharge chute, with areas adjacent to the decapper instrument and the centrifuge rotor also positive for HBV or HCV nucleic acid. Contamination was occasionally detected on exposed surfaces in areas without protective barriers between samples and personnel. After running known HCV-positive samples, at least one additional site of contamination was detected on an exposed area of the line. CONCLUSIONS: A low level of viral contamination of automated clinical laboratory equipment occurs in clinical use. Given the risks associated with highly infectious agents, there is a need for risk-mitigation procedures when handling all samples.


Assuntos
Automação Laboratorial , DNA Viral/sangue , Contaminação de Equipamentos , Hepacivirus/isolamento & purificação , Vírus da Hepatite B/isolamento & purificação , RNA Viral/sangue , DNA Viral/genética , Hepacivirus/genética , Vírus da Hepatite B/genética , Humanos , Reação em Cadeia da Polimerase , RNA Viral/genética , Comportamento de Redução do Risco
13.
Am J Clin Pathol ; 161(6): 561-569, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38345305

RESUMO

OBJECTIVES: Informal payments (IPs) are unofficial cash or in-kind payments for goods or services that should be covered by the health care system. They are a common but regressive method of financing health care in low- and lower-middle-income countries (LMICs). This study aims to characterize the prevalence and impact of IPs on pathology and laboratory medicine (PALM) services. METHODS: From September 2021 to September 2022, PALM staff were surveyed about the frequency, determinants, and impacts of IPs in their respective workplaces. RESULTS: In total, 268 responses were received, and 46.6% (125/268) reported experience with IPs. These 125 participants were more likely to work in the public sector and in LMICs. Approximately 65% reported accepting IPs to perform tests or release results. Obtaining faster results was the most commonly perceived reason for patients offering IPs. Overall, participants reported that IPs had more negative than positive impacts on their workplace. CONCLUSIONS: This represents a first step in characterizing IPs within PALM and how this practice may affect access to these services in LMICs. Specifically, the fact that faster turnaround time was the most frequently perceived reason for offering IPs uncovers a potential barrier to improving PALM capacity in these regions.


Assuntos
Serviços de Laboratório Clínico , Humanos , Serviços de Laboratório Clínico/economia , Serviços de Laboratório Clínico/estatística & dados numéricos , Inquéritos e Questionários , Feminino , Masculino , Adulto , Financiamento Pessoal , Países em Desenvolvimento , Atenção à Saúde/economia , Patologia Clínica/economia , Pessoa de Meia-Idade
14.
Sci Adv ; 10(8): eadl1258, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38381834

RESUMO

Adrenal Cushing's syndrome is a disease of cortisol hypersecretion often caused by mutations in protein kinase A catalytic subunit (PKAc). Using a personalized medicine screening platform, we discovered a Cushing's driver mutation, PKAc-W196G, in ~20% of patient samples analyzed. Proximity proteomics and photokinetic imaging reveal that PKAcW196G is unexpectedly distinct from other described Cushing's variants, exhibiting retained association with type I regulatory subunits (RI) and their corresponding A kinase anchoring proteins (AKAPs). Molecular dynamics simulations predict that substitution of tryptophan-196 with glycine creates a 653-cubic angstrom cleft between the catalytic core of PKAcW196G and type II regulatory subunits (RII), but only a 395-cubic angstrom cleft with RI. Endocrine measurements show that overexpression of RIα or redistribution of PKAcW196G via AKAP recruitment counteracts stress hormone overproduction. We conclude that a W196G mutation in the kinase catalytic core skews R subunit selectivity and biases AKAP association to drive Cushing's syndrome.


Assuntos
Síndrome de Cushing , Humanos , Síndrome de Cushing/genética , Proteínas de Ancoragem à Quinase A/genética , Proteínas de Ancoragem à Quinase A/metabolismo , Transdução de Sinais , Domínio Catalítico , Viés
16.
Am J Pathol ; 180(2): 446-56, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22122984

RESUMO

An important precondition for the successful development of diagnostic assays of cerebrospinal fluid (CSF) biomarkers of age-related neurodegenerative diseases is an understanding of the dynamic nature of the CSF proteome during the normal aging process. In this study, a novel proteomic technology was used to quantify hundreds of proteins simultaneously in the CSF from 90 cognitively normal adults 21 to 85 years of age. SomaLogic's highly multiplexed proteomic platform can measure more than 800 proteins simultaneously from small volumes of biological fluids using novel slow off-rate modified aptamer (SOMAmer) protein affinity reagents with sensitivity, specificity, and dynamic ranges that meet or exceed those of enzyme-linked immunosorbent assays. In the first application of this technology to CSF, we detected 248 proteins that possessed signals greater than twofold over background. Several novel correlations between detected protein concentrations and age were discovered that indicate that both inflammation and response to injury in the central nervous system may increase with age. Applying this powerful proteomic approach to CSF provides potential new insight into the aging of the human central nervous system that may have utility in discovering new disease-related changes in the CSF proteome.


Assuntos
Envelhecimento/metabolismo , Aptâmeros de Nucleotídeos/metabolismo , Proteínas do Líquido Cefalorraquidiano/análise , Análise Serial de Proteínas/métodos , Proteoma/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/genética , Biomarcadores/líquido cefalorraquidiano , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteoma/genética , Adulto Jovem
17.
Adv Exp Med Biol ; 735: 283-300, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23402035

RESUMO

Progression from health to disease is accompanied by complex changes in protein expression in both the circulation and affected tissues. Large-scale comparative interrogation of the human proteome can offer insights into disease biology as well as lead to the discovery of new biomarkers for diagnostics, new targets for therapeutics, and can identify patients most likely to benefit from treatment. Although genomic studies provide an increasingly sharper understanding of basic biological and pathobiological processes, they ultimately only offer a prediction of relative disease risk, whereas proteins offer an immediate assessment of "real-time" health and disease status. We have recently developed a new proteomic technology, based on modified aptamers, for biomarker discovery that is capable of simultaneously measuring more than a thousand proteins from small volumes of biological samples such as plasma, tissues, or cells. Our technology is enabled by SOMAmers (Slow Off-rate Modified Aptamers), a new class of protein binding reagents that contain chemically modified nucleotides that greatly expand the physicochemical diversity of nucleic acid-based ligands. Such modifications introduce functional groups that are absent in natural nucleic acids but are often found in protein-protein, small molecule-protein, and antibody-antigen interactions. The use of these modifications expands the range of possible targets for SELEX (Systematic Evolution of Ligands by EXponential Enrichment), results in improved binding properties, and facilitates selection of SOMAmers with slow dissociation rates. Our assay works by transforming protein concentrations in a mixture into a corresponding DNA signature, which is then quantified on current commercial DNA microarray platforms. In essence, we take advantage of the dual nature of SOMAmers as both folded binding entities with defined shapes and unique nucleic acid sequences recognizable by specific hybridization probes. Currently, our assay is capable of simultaneously measuring 1,030 proteins, extending to sub-pM detection limits, an average dynamic range of each analyte in the assay of > 3 logs, an overall dynamic range of at least 7 logs, and a throughput of one million analytes per week. Our collection includes SOMAmers that specifically recognize most of the complement cascade proteins. We have used this assay to identify potential biomarkers in a range of diseases such as malignancies, cardiovascular disorders, and inflammatory conditions. In this chapter, we describe the application of our technology to discovering large-scale protein expression changes associated with chronic kidney disease and non-small cell lung cancer. With this new proteomics technology-which is fast, economical, highly scalable, and flexible--we now have a powerful tool that enables whole-proteome proteomics, biomarker discovery, and advancing the next generation of evidence-based, "personalized" diagnostics and therapeutics.


Assuntos
Biomarcadores/análise , Diagnóstico , Tratamento Farmacológico/métodos , Proteômica/métodos , Animais , Proteínas Sanguíneas/química , Inativadores do Complemento/farmacologia , Proteínas do Sistema Complemento/fisiologia , Humanos , Proteínas/química
18.
Clin Chim Acta ; 543: 117274, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36934953

RESUMO

BACKGROUND: The standard approach for benzodiazepine detection often includes immunoassay followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The illicit use of non-prescribed benzodiazepines has been trending up nationally. METHODS: We developed and validated an improved LC-MS/MS assay for benzodiazepine detection in urine. We expanded the testing panel by adding five drugs to the previous panel of ten. We determined the prevalence of individual benzodiazepines in our patient population. Immunoassay results were compared with LC-MS/MS to evaluate assay performance. RESULTS: Clonazepam and alprazolam were the most common benzodiazepines present. Etizolam and flualprazolam were also prevalent in Washington State. Compared with the LC-MS/MS assay, the immunoassay had variable cross-reactivity, which explained false negative and false positive immunoassay results. The inclusion of new drugs in the LC-MS/MS panel significantly reduced the incidence of immunoassay results interpreted as falsely positive. CONCLUSION: New illicit benzodiazepines have emerged regionally and nationally. The inclusion of novel drugs in LC-MS/MS assay was helpful in properly characterizing the epidemiology of benzodiazepine use in our patient population. This information will lead to better assay result interpretations and patient care, and our experiences provide a roadmap for other clinical laboratories looking to expand their testing menu or transition to new instrumentation.


Assuntos
Benzodiazepinas , Espectrometria de Massas em Tandem , Humanos , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos , Washington , Benzodiazepinas/urina , Clonazepam
19.
J Pathol Inform ; 14: 100303, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36941960

RESUMO

Background: Reflexive laboratory testing workflows can improve the assessment of patients receiving pain medications chronically, but complex workflows requiring pathologist input and interpretation may not be well-supported by traditional laboratory information systems. In this work, we describe the development of a web application that improves the efficiency of pathologists and laboratory staff in delivering actionable toxicology results. Method: Before designing the application, we set out to understand the entire workflow including the laboratory workflow and pathologist review. Additionally, we gathered requirements and specifications from stakeholders. Finally, to assess the performance of the implementation of the application, we surveyed stakeholders and documented the approximate amount of time that is required in each step of the workflow. Results: A web-based application was chosen for the ease of access for users. Relevant clinical data was routinely received and displayed in the application. The workflows in the laboratory and during the interpretation process served as the basis of the user interface. With the addition of auto-filing software, the return on investment was significant. The laboratory saved the equivalent of one full-time employee in time by automating file management and result entry. Discussion: Implementation of a purpose-built application to support reflex and interpretation workflows in a clinical pathology practice has led to a significant improvement in laboratory efficiency. Custom- and purpose-built applications can help reduce staff burnout, reduce transcription errors, and allow staff to focus on more critical issues around quality.

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