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1.
Clin Chim Acta ; 502: 128-132, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31883925

RESUMO

BACKGROUND: Daratumumab (DARA) is a fully human anti-CD38 IgG1-κ monoclonal antibody drug used in the treatment of multiple myeloma (MM). While serum protein electrophoresis (SPEP) is an important assay for diagnosis and monitoring of patients with MM, DARA can appear in the γ-region as a single band and interfere with the interpretation of SPEP results. An approach to detect the interference is measuring the quantity of DARA in serum samples and assessing its impact on SPEP results. Immunoassays based on label-free technologies, i.e. label-free immunoassays (LFIA's), can achieve real-time immunometric measurement without attaching a reporter molecule (enzyme, fluorophore, etc.) to the immunocomplex. The recorded time course of the immunocomplex formation allows for quantitation on initial binding rate, which facilitates rapid measurement within a few minutes. Based on the thin-film interferometry (TFI) technology, a rapid LFIA was established for the quantitation of DARA in serum samples. METHODS: The TFI-based LFIA for DARA was validated for imprecision (CV), accuracy, limit of quantitation (LOQ), and analytical measurement range (AMR). Interference to the LFIA was evaluated using a group of protein samples, as well as hemolytic, lipemic, and icteric clinical samples. RESULTS: The precision of the TFI-based LFIA's for DARA ranged from 6.5% to 10.7% (within-run CV), and 7.4% to 11.6% (between-run CV), with a bias of -2.1% to 10.1%. The LOQ was 10 µg/ml (n = 4, CV 9.8%), with an AMR ranging from the LOQ to 1000 µg/ml. The LFIA was used to measure 37 patient samples submitted for SPEP testing. The LFIA results were 100% consistent with the history of DARA use as documented in the medical record. CONCLUSIONS: The TFI-based LFIA was successful at accurately identifying DARA in serum samples and can be used to identify DARA interference in SPEP testing. This work demonstrates the applicability of label-free technologies, particularly the TFI technology, to clinical diagnostic needs. Given the simplicity and the speed of the testing process, the TFI technology provides a unique testing approach for the measurement of proteins in clinical samples.

2.
J Appl Lab Med ; 4(2): 254-263, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31639672

RESUMO

BACKGROUND: Point-of-care testing (POCT) devices are designed for clinical laboratory testing at the bedside or near the patient and can significantly reduce the turnaround time for laboratory test results. The next generation for clinical laboratory testing may be devices that are worn or attached to the patient. CONTENT: POCT devices that are designed where samples are tested directly on the patient include bilirubinometers, pulse oximeters, breathalyzers (for alcohol and, more recently, cannabinoid detection), transcutaneous blood gas analyses, and novel testing applications such as glucose and tumor signatures following surgical excision. The utility of these devices with special reference for use within the intensive care unit and the emergency department is reviewed. SUMMARY: It is likely that wearable POCT devices will be developed in the future that can meet current and emerging clinical needs. Advancements in biomedical engineering and information technology will be needed in the creation of next-generation devices.

3.
J Appl Lab Med ; 4(1): 61-68, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31639708

RESUMO

BACKGROUND: Deficiency of 25-hydroxyvitamin D in serum is endemic in the general population, and testing for this hormone is useful in accessing a patient's overall health and well-being. METHODS: We obtained blood from 216 hospitalized patients and outpatients divided into 4 groups thought to be at high risk of 25-hydroxyvitamin D deficiency: homeless, recreational drug abusers, psychiatric patients with limited access to the outdoors, and those infected with HIV. The 25-hydroxyvitamin D concentrations from these patients were determined with 2 different methodologies (immunoassay and mass spectrometry) and compared against 25-hydroxyvitamin D concentrations in apparently healthy controls. We hypothesized that these groups may be at higher risk for vitamin D deficiency because of poor nutrition, inadequate housing, restricted access to outdoors, or the presence of chronic disease. RESULTS: For each of the patient groups including healthy controls, the median concentration of 25-hydroxyvitamin D was below 30 ng/mL, indicating deficiency. Comparisons between the healthy controls and the other groups were not statistically significant with either methodology, except for the homeless patients in whom a higher number of individuals had 25-hydroxyvitamin D concentrations below 20 ng/mL. Results between the 2 testing platforms demonstrated that only 52% of the specimens analyzed by immunoassay agreed within ±10% of the LC-MS/MS results, with an overall correlation coefficient to 0.920. The degree of concordance for deficiency with 2 published cutoffs of 20 and 30 ng/mL was 91% and 91%, respectively. CONCLUSIONS: Vitamin D deficiency is a common finding in all the populations studied. The Lumipulse® G vitamin D immunoassay is an alternative for detecting vitamin D deficiency.

4.
J Appl Lab Med ; 3(5): 839-846, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-31639758

RESUMO

BACKGROUND: The XW-100 hematology analyzer (Sysmex America) is the first complete blood count (CBC) instrument waived by the US Food and Drug Administration. This analyzer also tests for a 3-part white blood cell count differential. METHODS: The XW-100 analyzer was evaluated for preanalytical specimen variables including the need for mixing, specimen storage conditions, freeze-thaw cycles, the effect of under filling of tubes, precision, linearity, carryover, limits of the blank, detection, and quantification and interferences from common and CBC-specific substances. The clinical study examined 586 blood samples from 6 CLIA-waived clinical sites and 6 paired moderately complex sites. The point-of-care sites had different medical specialties and were using inexperienced operators. The results of 8 measurements and 4 calculated parameters were compared to a moderately complex point-of-care hematology analyzer (pocH-100i, Sysmex). RESULTS: The precision was <6% for all analytics, and there was no carryover noted. Samples containing interfering substances were appropriately flagged or suppressed by the instrument. The correlation to the predicate analyzer was highly concordant, producing near unity slope and intercept and minimal bias. Delays from sample collection to testing resulted in decreased performance. The percentage of samples inside the allowable error was >98.8% for all parameters studied. CONCLUSION: This CLIA-waived hematology analyzer produces acceptable results and can be used in offices and clinics.

5.
J Clin Microbiol ; 57(11)2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31434724

RESUMO

Laboratory tests for Clostridioides difficile infection (CDI) rely on the detection of free toxin or molecular detection of toxin genes. The Singulex Clarity C. diff toxins A/B assay is a rapid, automated, and ultrasensitive assay that detects C. difficile toxins A and B in stool. We compared CDI assays across two prospective multicenter studies to set a cutoff for the Clarity assay and to independently validate the performance compared with that of a cell culture cytotoxicity neutralization assay (CCCNA). The cutoff was set by two sites testing fresh samples from 897 subjects with suspected CDI and then validated at four sites testing fresh samples from 1,005 subjects with suspected CDI. CCCNA testing was performed at a centralized laboratory. Samples with discrepant results between the Clarity assay and CCCNA were retested with CCCNA when the Clarity result agreed with that of at least one comparator method; toxin enzyme immunoassays (EIA), glutamate dehydrogenase (GDH) detection, and PCR were performed on all samples. The cutoff for the Clarity assay was set at 12.0 pg/ml. Compared to results with CCCNA, the Clarity assay initially had 85.2% positive agreement and 92.4% negative agreement. However, when samples with discrepant results between the Clarity assay and CCCNA in the validation study were retested by CCCNA, 13/17 (76.5%) Clarity-negative but CCCNA-positive samples (Clarity+/CCCNA-) became CCCNA-, and 5/26 (19.2%) Clarity+/CCCNA- samples became CCCNA+, resulting in a 96.3% positive agreement and 93.0% negative agreement between Clarity and CCCNA results. The toxin EIA had 59.8% positive agreement with CCCNA. The Clarity assay was the most sensitive free-toxin immunoassay, capable of providing CDI diagnosis in a single-step solution. A different CCCNA result was reported for 42% of retested samples, increasing the positive agreement between Clarity and CCCNA from 85.2% to 96.3% and indicating the challenges of comparing free-toxin results to CCCNA results as a reference standard.

6.
Clin Biochem ; 73: 35-43, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31247187

RESUMO

BACKGROUND: Cardiac troponin (cTn) is a complex of three subunits (T, I, and C), with some studies reporting that ~5-10% is cytosolic and unbound ('free'). It has been hypothesized that free cTn is released before complex and before or without cell death dependent on the severity of ischemia. In this context, new generation assays that can discriminate free, binary (IC) and ternary (TIC) complex forms may aid to differentiate between type 1 myocardial infarction (MI) and cTn elevations due to different etiologies, e.g. demand ischemia and type 2 MI. METHODS: Serial plasma samples from six type 1 MI patients and twenty-seven patients with other cTnI elevations, e.g. due to demand ischemia and type 2 MI, were analyzed using high-sensitivity ET Healthcare Pylon assays for total cTnI, complex cTnI (IC and TIC), and cTnTIC. The specificity of the anti-cTnT antibody in the cTnTIC assay was such that only full-size cTnTIC is detected. In vitro stability of different cTnI forms was assessed by spiking free cTnI and cTnTIC in cTnI-free serum, incubating at 4 or 37 °C, and measuring different cTnI forms over 0-182 h. Presence of cytosolic free cTnI was evaluated on fixed rat cardiac tissue using an antibody against free cTnI. RESULTS: Pylon assays for total and complex cTnI tracked well over time with each other and gave similar results, both for type 1 MI and non-type 1 MI patients, indicating that the vast majority was complex cTnI. As a minority of complex cTnI was full-size cTnTIC, this indicated that complex cTnI mainly consisted of a degraded form of cTnTIC (low-molecular weight cTnTIC) and/or cTnIC. Full-size cTnTIC was more abundant in early compared to late samples. In vitro studies indicated that free cTnI and cTnTIC are not stable at 37 °C (28% and 11% recovery after 24 h, respectively) and this is also true to some extent for cTnTIC at 4 °C (60% recovery after 24 h). Free cTnI was not readily detected in rat cardiac tissue. CONCLUSIONS: In agreement with type 1 MI, cTnI in samples of patients with cTnI elevations due to other etiologies is found predominantly as complex cTnI, of which some is full-size cTnTIC. In most cases, assays for total and complex cTnI indicated there was little free cTnI; however, its presence cannot be completely excluded, due to the inability of its direct measurement and limited stability.


Assuntos
Infarto do Miocárdio/sangue , Miocárdio/metabolismo , Troponina I/sangue , Troponina T/sangue , Animais , Linhagem Celular , Feminino , Humanos , Masculino , Infarto do Miocárdio/classificação , Ratos , Ratos Nus
7.
Clin Chem Lab Med ; 57(9): 1382-1387, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-30753155

RESUMO

Background Biological variation studies have shown that the complete blood count (CBC) has narrow within-individual variation and wide group variation, indicating that the use of reference intervals (RIs) is challenging. The aim of this study was to examine differences in CBC RIs according to race/ethnicity in a multiethnic population at a hospital in San Francisco in hopes of improving the medical utility of CBC testing. Methods Subject data were obtained by screening CBC results from the medical records of outpatients meeting certain criteria who visited Zuckerberg San Francisco General Hospital from April 2017 to January 2018. From these records, sex- and race/ethnicity-specific CBC RIs were calculated as the 2.5th to 97.5th percentiles. Results From a total of 552 subjects, 47.9% were male (65 White, 50 Black, 71 Hispanic and 54 Asian) and 52.1% were female (51 White, 39 Black, 122 Hispanic and 72 Asian). The RIs of neutrophil, lymphocyte and eosinophil counts; and hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) showed significant differences (p<0.05) among the four racial/ethnic groups: neutrophil, lymphocyte and eosinophil counts; and MCHC in males, and hemoglobin, MCV, MCH and MCHC in females. Conclusions Race/ethnicity-specific CBC RIs should be taken into consideration in a multiethnic population to better interpret patient status and make progress toward precision medicine.

8.
Pract Lab Med ; 13: e00112, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30623006
9.
Eur Heart J Acute Cardiovasc Care ; 8(5): 395-403, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29737180

RESUMO

BACKGROUND: Copeptin in combination with troponin has been shown to have incremental value for the early rule-out of myocardial infarction, but its performance in Black patients specifically has never been examined. In light of a potential for wider use, data on copeptin in different relevant cohorts are needed. This is the first study to determine whether copeptin is equally effective at ruling out myocardial infarction in Black and Caucasian races. METHODS: This analysis of the CHOPIN trial included 792 Black and 1075 Caucasian patients who presented to the emergency department with chest pain and had troponin-I and copeptin levels drawn. RESULTS: One hundred and forty-nine patients were diagnosed with myocardial infarction (54 Black and 95 Caucasian). The negative predictive value of copeptin at a cut-off of 14 pmol/l (as in the CHOPIN study) for myocardial infarction was higher in Blacks (98.0%, 95% confidence interval (CI) 96.2-99.1%) than Caucasians (94.1%, 95% CI 92.1-95.7%). The sensitivity at 14 pmol/l was higher in Blacks (83.3%, 95% CI 70.7-92.1%) than Caucasians (53.7%, 95% CI 43.2-64.0%). After controlling for age, hypertension, heart failure, chronic kidney disease and body mass index in a logistic regression model, the interaction term had a P value of 0.03. A cut-off of 6 pmol/l showed similar sensitivity in Caucasians as 14 pmol/l in Blacks. CONCLUSIONS: This is the first study to identify a difference in the performance of copeptin to rule out myocardial infarction between Blacks and Caucasians, with increased negative predictive value and sensitivity in the Black population at a cut-off of 14 pmol/l. This also holds true for non-ST-segment elevation myocardial infarction and, although numbers were small, similar trends exist in the normal troponin population. This may have significant implications for early rule-out strategies using copeptin.

11.
J Anal Toxicol ; 43(4): 316-320, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30462225

RESUMO

Benzodiazepines (BZDs) are widely used for treatment of anxiety and insomnia, however, this class of drugs is also commonly abused. Many different BZDs and analogs have been produced that are not FDA-approved. We tested 15 of these with the ThermoFisher CEDIA® BZD-immunoassay. With the exception of ketazolam, all compounds showed significant reactivity, highlighting the need for mass spectrometry confirmation assays. We developed a liquid-chromatography high-resolution mass spectrometry method for the detection of these 15 non-FDA approved BZDs. The limit of detection for most compounds ranged from 1 to 50 ng/mL, with mostly positive matrix effects observed in urine and negative matrix effects in serum. In a clinical research case, clonazolam and etizolam were detected in serum at 10.2 and 281 ng/mL, with an apparent elimination half-life of 3.6 and 4.8 hours, respectively. Although we did not detect non-FDA approved BZDs in 211 urine samples that were previously determined to be BZD-positive by immunoassay, abuse of these drugs is on the rise and clinical and forensic toxicology laboratories should consider developing methods to detect them.


Assuntos
Benzodiazepinas/sangue , Benzodiazepinas/urina , Cromatografia Líquida/métodos , Toxicologia Forense/métodos , Imunoensaio/métodos , Detecção do Abuso de Substâncias/métodos , Espectrometria de Massas em Tandem/métodos , Adulto , Drogas Desenhadas , Diazepam/análogos & derivados , Diazepam/sangue , Meia-Vida , Humanos , Limite de Detecção , Masculino , Concentração Osmolar , Tranquilizantes/sangue
12.
JAMA Cardiol ; 3(12): 1206-1210, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30383171

RESUMO

Importance: Transverse tubule remodeling is a hallmark of heart failure. Cardiac bridging integrator 1 (cBIN1) is a circulating membrane scaffolding protein that is essential for transverse tubule health, and its plasma level declines with disease. Objective: To determine if a cBIN1-derived score can serve as a diagnostic biomarker of heart failure with preserved ejection fraction (HFpEF). Design, Setting, and Participants: In this cohort study, the cBIN1 score (CS) was determined from enzyme-linked immunoabsorbent assay-measured plasma cBIN1 concentrations from study participants in an ambulatory heart failure clinic at Cedars-Sinai Medical Center. Consecutive patients with a confirmed diagnosis of heart failure with preserved ejection fraction (HFpEF; defined by a left ventricular ejection fraction ≥50%) were recruited from July 2014 to November 2015 and compared with age-matched and sex-matched healthy volunteers with no known cardiovascular diagnoses and participants with risk factors for heart failure but no known HFpEF. Baseline characteristics and 1-year longitudinal clinical information were obtained through electronic medical records. Data analysis occurred from November 2016 to November 2017. Main Outcomes and Measures: The analysis examined the ability of the CS and N-terminal pro-B-type natriuretic peptide (NT-proBNP) results to differentiate among patients with HFpEF, healthy control participants, and control participants with risk factors for heart failure. We further explored the association of the CS with future cardiovascular hospitalizations. Results: A total of 52 consecutive patients with a confirmed diagnosis of HFpEF were enrolled (mean [SD] age, 57 [15] years; 33 [63%] male). The CS values are significantly higher in the patients with HFpEF (median [interquartile range (IQR)], 1.85 [1.51-2.28]) than in the 2 control cohorts (healthy control participants: median [IQR], -0.03 [-0.48 to 0.41]; control participants with risk factors only: median [IQR], -0.08 [-0.75 to 0.42]; P < .001). For patients with HFpEF, the CS outperforms NT-proBNP when the comparator group was either healthy control participants (CS: area under curve [AUC], 0.98 [95% CI, 0.96-1.00]; NT-proBNP level: AUC, 0.93 [95% CI, 0.88-0.99]; P < .001) or those with risk factors (CS: AUC, 0.98 [95% CI, 0.97-1.00]; NT-proBNP: AUC, 0.93 [95% CI, 0.88-0.99]; P < .001). Kaplan-Meier analysis of 1-year cardiovascular hospitalizations adjusted for age, sex, body mass index, and NT-proBNP levels reveals that patients with HFpEF with CS greater than or equal to 1.80 have a hazard ratio of 3.8 (95% CI, 1.3-11.2; P = .02) for hospitalizations compared with those with scores less than 1.80. Conclusions and Relevance: If further validated, the plasma CS, a marker of transverse tubule dysfunction, may serve as a biomarker of cardiomyocyte remodeling that has the potential to aide in the diagnosis of HFpEF.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/sangue , Insuficiência Cardíaca/diagnóstico , Hospitalização/tendências , Proteínas Nucleares/sangue , Volume Sistólico/fisiologia , Proteínas Supressoras de Tumor/sangue , Biomarcadores/sangue , Feminino , Seguimentos , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Prognóstico , Precursores de Proteínas , Índice de Gravidade de Doença , Função Ventricular Esquerda
13.
Clin Biochem ; 61: 18-22, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30236830

RESUMO

OBJECTIVE: A multisite investigation compared the analytical performance of a point-of-care (POC) HbA1c device with multiple commonly used HbA1c laboratory methods and an NGSP (National Glycohemoglobin Standardization Program) reference method. RESEARCH DESIGN AND METHODS: The Afinion AS100 POC device analyzed HbA1c using 618 EDTA whole blood excess patient specimens with clinically indicated HbA1c testing. Results were compared to measurements across five clinical laboratories and the NGSP reference method. Precision was evaluated over 8-10 consecutive days for low-, mid-, and high-range HbA1c specimens at all five sites. RESULTS: Over a wide range of HbA1c values (4.0%-15% HbA1c), 97.1% of the POC results and 94.5% of routine laboratory results fell within the target value of ±6% of the NGSP reference method results. The POC HbA1c results at 6.5% exhibited a total relative bias of -0.6% (-0.04% HbA1c) compared to the reference method while the aggregate of laboratory methods displayed a relative bias of -0.9% (-0.06% HbA1c). The total imprecision of the POC results ranged from 0.74-2.13% CV across the analytic measurement range compared to 0.81-3.23% CV for the routine laboratory methods. CONCLUSIONS: The accuracy and precision of the Afinion POC HbA1c method was comparable to the laboratory HbA1c methods supporting the FDA's recent approval of the Afinion HbA1c Dx device for use in the diagnosis of diabetes.


Assuntos
Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Hemoglobina A Glicada/análise , Testes Imediatos , Aprovação de Equipamentos , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 2/diagnóstico , Humanos , Teste de Materiais , Reprodutibilidade dos Testes , Estados Unidos , United States Food and Drug Administration
14.
Rheumatology (Oxford) ; 57(9): 1632-1640, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29873771

RESUMO

Objective: We previously described the multiplex autoantibody SLE-key Rule-Out test, which detects a signature of autoantibody reactivity that distinguishes healthy subjects from SLE patients with 94% sensitivity, 75% specificity and 93% negative predictive value; thus, an individual manifesting a positive Rule-Out test score is unlikely to have SLE (e.g. lupus is excluded). The objective of this current study was to evaluate the stability of the lupus-associated signature over time. Methods: We used banked serum samples from healthy subjects (n = 51) and lupus patients (n = 50 individual samples and n = 181 paired samples, for a total of n = 412 serum samples). The samples were drawn at different times after diagnosis to analyse the impact on the SLE-key Rule-Out test of time elapsed since diagnosis and any changes in disease activity (as reflected by the SLEDAI score). Results: The SLE signature remains stable for the first 10 years after diagnosis; in this time frame, <10% of patients manifested a positive Rule-Out score and the SLE-key Rule-Out score was independent of the underlying disease activity as reflected by the SLEDAI score. After ⩾10 years, ∼30% of lupus subjects scored as SLE Ruled-Out; the proportion of patients manifesting this status was even greater in the subset of individuals with a SLEDAI score of 0. Conclusion: These findings raise the possibility that a significant number of SLE patients manifest a change in their serological signature over time, and that such a signature change may signify an evolution in the immunological features of their disease relevant to patient management.


Assuntos
Autoanticorpos/sangue , Previsões , Lúpus Eritematoso Sistêmico/imunologia , Adulto , Biomarcadores/sangue , Progressão da Doença , Feminino , Seguimentos , Humanos , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/diagnóstico , Masculino , Curva ROC , Testes Sorológicos , Índice de Gravidade de Doença
15.
Am J Clin Pathol ; 150(2): 96-104, 2018 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-29850771

RESUMO

Objectives: In the United States, minimum standards for quality control (QC) are specified in federal law under the Clinical Laboratory Improvement Amendment and its revisions. Beyond meeting this required standard, laboratories have flexibility to determine their overall QC program. Methods: We surveyed chemistry and immunochemistry QC procedures at 21 clinical laboratories within leading academic medical centers to assess if standardized QC practices exist for chemistry and immunochemistry testing. Results: We observed significant variation and unexpected similarities in practice across laboratories, including QC frequency, cutoffs, number of levels analyzed, and other features. Conclusions: This variation in practice indicates an opportunity exists to establish an evidence-based approach to QC that can be generalized across institutions.


Assuntos
Centros Médicos Acadêmicos/normas , Química Clínica/normas , Serviços de Laboratório Clínico/normas , Imunoquímica/normas , Controle de Qualidade , Humanos , Laboratórios/normas , Inquéritos e Questionários , Estados Unidos
16.
Clin Infect Dis ; 66(11): 1678-1686, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29438475

RESUMO

Background: Blood cultures are approximately 50% sensitive for diagnosing invasive candidiasis. The T2Candida nanodiagnostic panel uses T2 magnetic resonance and a dedicated instrument to detect Candida directly within whole blood samples. Methods: Patients with Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, or Candida krusei candidemia were identified at 14 centers using diagnostic blood cultures (dBCs). Follow-up blood samples were collected concurrently for testing by T2Candida and companion cultures (cBCs). T2Candida results are reported qualitatively for C. albicans/C. tropicalis, C. glabrata/C. krusei, and C. parapsilosis. T2Candida and cBCs were positive if they detected a species present in the dBC. Results: Median time between collection of dBC and T2Candida/cBC samples in 152 patients was 55.5 hours (range, 16.4-148.4). T2Candida and cBCs were positive in 45% (69/152) and 24% (36/152) of patients, respectively (P < .0001). T2Candida clinical sensitivity was 89%, as positive results were obtained in 32/36 patients with positive cBCs. Combined test results were both positive (T2+/cBC+), 21% (32/152); T2+/cBC-, 24% (37/152); T2-/cBC+, 3% (4/152); and T2-/cBC-, 52% (79/152). Prior antifungal therapy, neutropenia, and C. albicans candidemia were independently associated with T2Candida positivity and T2+/cBC- results (P values < .05). Conclusions: T2Candida was sensitive for diagnosing candidemia at the time of positive blood cultures. In patients receiving antifungal therapy, T2Candida identified bloodstream infections that were missed by cBCs. T2Candida may improve care by shortening times to Candida detection and species identification compared to blood cultures, retaining sensitivity during antifungal therapy and rendering active candidemia unlikely if results are negative. Clinical Trials Registration: NCT01525095.


Assuntos
Candida/isolamento & purificação , Candidemia/sangue , Candidemia/diagnóstico , Espectroscopia de Ressonância Magnética/métodos , Testes Sorológicos/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade
17.
Clin Chem ; 64(4): 645-655, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29343532

RESUMO

This document is an essential companion to the third iteration of the National Academy of Clinical Biochemistry [NACB,8 now the American Association for Clinical Chemistry (AACC) Academy] Laboratory Medicine Practice Guidelines (LMPG) on cardiac markers. The expert consensus recommendations were drafted in collaboration with the International Federation of Clinical Chemistry and Laboratory Medicine Task Force on Clinical Applications of Bio-Markers (IFCC TF-CB). We determined that there is sufficient clinical guidance on the use of cardiac troponin (cTn) testing from clinical practice groups. Thus, in this expert consensus document, we focused on clinical laboratory practice recommendations for high-sensitivity (hs)-cTn assays. This document utilized the expert opinion class of evidence to focus on the following 10 topics: (a) quality control (QC) utilization, (b) validation of the lower reportable analytical limits, (c) units to be used in reporting measurable concentrations for patients and QC materials, (d) 99th percentile sex-specific upper reference limits to define the reference interval; (e) criteria required to define hs-cTn assays, (f) communication with clinicians and the laboratory's role in educating clinicians regarding the influence of preanalytic and analytic problems that can confound assay results, (g) studies on hs-cTn assays and how authors need to document preanalytical and analytical variables, (h) harmonizing and standardizing assay results and the role of commutable materials, (i) time to reporting of results from sample receipt and sample collection, and (j) changes in hs-cTn concentrations over time and the role of both analytical and biological variabilities in interpreting results of serial blood collections.


Assuntos
Síndrome Coronariana Aguda/diagnóstico , Testes de Química Clínica , Troponina I/sangue , Troponina T/sangue , Biomarcadores/sangue , Serviços de Laboratório Clínico , Humanos , Internacionalidade , Controle de Qualidade , Padrões de Referência
19.
Ann Emerg Med ; 71(3): 306-313, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29103798

RESUMO

STUDY OBJECTIVE: Cannabis and its principal active constituent, Δ9-tetrahydrocannabinol (THC), are increasingly available as edibles resembling commercially available food products. In this case series, we describe a population of predominantly pediatric patients who were inadvertently exposed to a THC-containing product in San Francisco. METHODS: Twelve children and 9 adults were identified, with 16 patients having detectable serum THC and THC metabolites. All patients presented to hospitals with a variety of constitutional symptoms and all were discharged home within 12 hours. RESULTS: In general, pediatric patients had more severe symptoms and longer hospital length of stay, and, uniquely, a majority presented with leukocytosis and elevated lactic acid levels. CONCLUSION: We recommend that efforts be made to increase general public awareness in regard to the potential hazards of THC-containing edibles resembling commercially available food products.


Assuntos
Doces , Cannabis/envenenamento , Dronabinol/análogos & derivados , Abuso de Maconha/sangue , Detecção do Abuso de Substâncias/métodos , Adolescente , Adulto , Criança , Dronabinol/sangue , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Hipnóticos e Sedativos , Incidência , Masculino , Abuso de Maconha/diagnóstico , Abuso de Maconha/epidemiologia , Pessoa de Meia-Idade , São Francisco/epidemiologia , Adulto Jovem
20.
J Anal Toxicol ; 42(3): 163-169, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29272445

RESUMO

The postmortem redistribution phenomenon is an important factor in the interpretation of blood drug concentrations as a cause or factor in death. Intraosseous fluid (IOF) may serve as an alternative matrix for drug testing. Intraosseous fluid was collected from the left and right tibias and humerus of 29 decedents using the Arrow EZ-IO Intraosseous Vascular Access System. Standard autopsy specimens including blood were also collected at the same time during autopsy. Blood and IOF specimens were screened by immunoassay for opioids, fentanyl analogs, oxycodone, methadone, cocaine, methamphetamine, amphetamines, phencyclidine, tricyclic antidepressants, benzodiazepines and cannabinoids, using commercially available enzyme-linked immunosorbent assay (ELISA) kits. Correlation between cardiac/central blood ELISA and IOF ELISA results was mostly 100% for drug targets. Further blood confirmation analysis was performed by gas chromatography mass spectrometry also showed comparable correlation to IOF screen results. There was no significant difference between the IOF sites or sides of the body. This novel study supports the use of IOF as an alternative postmortem specimen for toxicological investigations as a potentially less-compromised tissue in decomposed or traumatized bodies. Preliminary data is provided for the screening of common drugs of abuse in IOF that may show to be subject to alternative rates of postmortem redistribution than to that of other biological specimens in future studies that quantitate IOF drug concentrations.


Assuntos
Líquidos Corporais/química , Ensaio de Imunoadsorção Enzimática , Toxicologia Forense/métodos , Úmero/química , Detecção do Abuso de Substâncias/métodos , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Tíbia/química , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Autopsia , Causas de Morte , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Pessoa de Meia-Idade , Mudanças Depois da Morte , Valor Preditivo dos Testes , Dados Preliminares , Reprodutibilidade dos Testes , Transtornos Relacionados ao Uso de Substâncias/sangue , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Transtornos Relacionados ao Uso de Substâncias/mortalidade , Sus scrofa , Adulto Jovem
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