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Objectives Recently modified 2-tier testing (MTTT) algorithms using 2 enzyme immunoassays (EIAs) as opposed to an EIA followed by immunoblot have been approved by the US Food and Drug Administration (FDA) for the screening and confirmation of Lyme disease. The Quidel Sofia Lyme fluorescent immunoassay is a rapid lateral-flow method that can be performed in real time, permitting on-demand testing. We evaluated the performance of the Sofia assay as a first-tier test in an MTTT algorithm. Methods We compared the Sofia Lyme test with the Zeus ELISA Borrelia VlsE1/pepC10 lgG/IgM test, followed by the Zeus monovalent IgM/IgG EIA as the confirmatory test. Results When used as a first-tier test compared with a standard Zeus MTTT assay, the positive percentage agreement was 91.4%% (95% CI, 77.6%-97.0%). The negative percentage agreement was 100% (95% CI, 94.0%-100%). The overall agreement was 98.3% (95% CI, 94.2%-99.4%). κ = 0.945, indicating "almost perfect agreement." Conclusions The Sofia Lyme test performs well compared with an FDA-approved MTTT. [ABSTRACT FROM AUTHOR]

Objectives: We evaluated trends in non-Lyme disease tick-borne disease (NLTBI) testing at a national reference laboratory.Methods: Testing data performed at Quest Diagnostics during 2010 to 2016 were analyzed nationally and at the state level.Results: Testing and positivity for most NLTBIs increased dramatically from 2010 through 2016 based on testing from a large reference laboratory. The number of positive cases, though not as stringent as criteria for public health reporting, generally exceeds that reported by the Centers for Disease Control and Prevention. The frequency of NLTBI in the US is seasonal but testing activity and positive test results are observed throughout all months of the year. Positive results for NLTBI testing mostly originated from a limited number of states, indicating the geographic concentration and distribution of NLTBIs reported in this study.Conclusions: This report provides an important complementary source of data to best understand trends in and spread of NLTBI. [ABSTRACT FROM AUTHOR]

Context.--Previous studies evaluating point-of-care testing (POCT) for cardiac biomarkers did not use current recommendations for troponin cutoff values or recognize the recent universal definition of acute myocardial infarction. Traditionally, achieving optimal sensitivity for the detection of myocardial injury on initial presentation required combining cardiac troponin and/or creatine kinase isoenzyme MB with an early marker, usually myoglobin. In recent years, the performance of central laboratory combining cardiac troponin assays has improved significantly, potentially obviating the need for a multimarker panel to achieve optimum sensitivity. Objective.--To compare 2 commonly used POCT strategies to a fourth generation, central laboratory cardiac troponin T assay on first-draw specimens from patients being evaluated for acute myocardial infarction in the emergency department. The 2 strategies included a traditional POCT multimarker panel and a newer POCT method using cardiac troponin I alone. Design.--Blood specimens from 204 patients presenting to the emergency department with signs and/or symptoms of myocardial ischemia were measured on the 2 POCT systems and by a central laboratory method. The diagnosis for each patient was determined by retrospective chart review. Results.--The cardiac troponin T assasy alone was more sensitive for acute myocardial infarction than the multimarker POCT panel with equal or better specificity. When compared with a POCT troponin I, the cardiac troponin T was also more sensitive, but this difference was not significant. The POCT troponin I alone also had the same sensitivity as the multimarker panel. Conclusions.--Testing for combining cardiac troponin alone using newer, commercially available, central laboratory or POCT assays performed with equal or greater sensitivity to acute myocardial infarction as the older, traditional, multimarker panel. In the near future, high-sensitivity, central laboratory troponins will be available for routine clinical use. As a result, the quality gap between central laboratories and older POCT methods will continue to widen, unless the performance of the POCT methods is improved., Current guidelines for cardiac markers of myocardial necrosis recommend a total turnaround time of less than 1 hour and preferably less than 30 minutes. (1) This recommendation reflects the importance [...]

* Context.--In clinical trials, N-terminal pro-brain natriuretic peptide (NT-proBNP) testing has been shown to be valuable for diagnosis and triage of patients with acute decompensated heart failure. It is not [...]

Objectives: We evaluated trends in Lyme disease (LD) testing at a national reference laboratory.Methods: LD screening enzyme immunoassay and Western blot testing data performed at Quest Diagnostics during 2010 to 2016 were analyzed nationally and at the state level.Results: Overall, 593,800 (11.3%) results were positive of 5,255,636 tests. There was an increase in the rate of positivity over the last 2 years of the study and an increase in the number of positive tests in 2016. Positive tests were observed in all 50 states and the District of Columbia. New York had the most positive tests, whereas Connecticut had the highest positivity rate when normalized to state populations. Some states with historically low rates of LD (eg, Texas, Florida, and California) showed significant increases in testing and positivity rates over time.Conclusions: LD testing and positivity have increased in recent years, including in states not historically associated with the disease. [ABSTRACT FROM AUTHOR]

Objectives We evaluated changes in the testing menu, volume, and positivity rates for tick-borne illnesses in a New England medical center over an 11-year time frame. Methods Testing data were obtained by a retrospective review utilizing searchable data from a laboratory information system archive. Results Testing for tick-borne infections (TBI) increased 5.3-fold over an 11-year time period and the number of positive test results increased threefold. Annual rates for Lyme serology positivity varied from 14% to 29% and for western blot confirmation from 26% to 48%. Test volumes and the number of positive results increased for all TBI endemic to our region. Conclusions Our results confirm national trends suggesting increasing rates of TBI and substantially increased testing. This may reflect a greater incidence of TBI in our region and/or increased awareness of these infections. [ABSTRACT FROM AUTHOR]

Objectives: We evaluated changes in the testing menu, volume, and positivity rates for tick-borne illnesses in a New England medical center over an 11-year time frame.Methods: Testing data were obtained by a retrospective review utilizing searchable data from a laboratory information system archive.Results: Testing for tick-borne infections (TBI) increased 5.3-fold over an 11-year time period and the number of positive test results increased threefold. Annual rates for Lyme serology positivity varied from 14% to 29% and for western blot confirmation from 26% to 48%. Test volumes and the number of positive results increased for all TBI endemic to our region.Conclusions: Our results confirm national trends suggesting increasing rates of TBI and substantially increased testing. This may reflect a greater incidence of TBI in our region and/or increased awareness of these infections. [ABSTRACT FROM AUTHOR]

Examines the study of use and cost of bedside capillary testing in a teaching hospital. Information on patients and research methods for study at Massachusetts General Hospital; Examination of results of study; Details of costs of bedside glucose testing; Information on conclusions of study.

Background: The performance of point-of-care testing under controlled laboratory conditions may vary from results obtained in actual patient care settings. User errors are a major cause of this discrepancy. Methods: We studied the clinical performance of the Cardiac STATus (Spectral USA, Frederick, MD), a qualitative triple cardiac marker point-of-care test, under controlled laboratory conditions and in actual practice in an emergency department (ED) satellite laboratory. First-draw samples obtained from patients presenting to the hospital emergency department with chest pain were used for the study. Tests were performed in the chemistry research laboratory by a company product specialist or in an emergency department satellite laboratory by hospital staff. Test results were analyzed by correlation to the clinical discharge diagnosis. Results: In the emergency department, for the test system as a whole (any one or more marker(s) positive versus all three markers negative), sensitivity was 63%, specificity was 81%, positive predictive value was 26%, and negative predictive value was 95%. A manufacturer-supplied product specialist in a laboratory setting achieved very similar sensitivity, specificity, and positive and negative predictive values. Conclusions: The performance of this system under controlled laboratory conditions can be applied to estimate its performance at the point of care. [Copyright &y& Elsevier]

Abstract: Purpose: Exercise-associated hyponatremia (EAH), as defined by a blood sodium concentration [Na+] less than 135 mmol/L, may lead to hypotonic encephalopathy with fatal cerebral edema. Understanding the pathogenetic role of antidiuresis may lead to improved strategies for prevention and treatment. Methods: Normonatremic marathon runners were tested pre- and post-race for creatine kinase, interleukin-6, cortisol, prolactin, and arginine vasopressin. Similar testing also was carried out in runners with encephalopathy caused by EAH, including 2 cases with fatal cerebral edema. Results: Normonatremic runners (n = 33; 2001) with a mean 3% decrease in body weight showed a 40-fold increase in interleukin-6 (66.6 ± 11.9 pg/mL from 1.6 ± 0.5 pg/mL, P = .001), which was significantly correlated with increases in creatine kinase (r = 0.88, P = <.0001), cortisol (r = 0.70, P = .0003), and prolactin (r = 0.67, P <.007), but not arginine vasopressin (r = 0.44, P = .07). Collapsed runners with EAH (n = 22; 2004) showed a mean blood urea nitrogen less than 15 mg/dL with measurable plasma levels of arginine vasopressin (>0.5 pg/mL) in 43% of cases. Two marathon runners with fatal cerebral edema additionally showed less than maximally dilute urines (>100 mmol/kg/H2O) and urine [Na+] greater than 25 mEq/L. Conclusions: Cases of EAH fulfill the essential diagnostic criteria for the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Runners with hypotonic encephalopathy at subsequent races were treated with intravenous hypertonic (3%) saline on the basis of this paradigm, which resulted in rapid clinical improvement without adverse effects. Release of muscle-derived interleukin-6 may play a role in the nonosmotic secretion of arginine vasopressin, thereby linking rhabdomyolysis to the pathogenesis of EAH. [Copyright &y& Elsevier]