Elizabeth T Leary

Pacific Biomarkers, Seattle, Washington, United States

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Publications (6)22.47 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: This position paper reviews how the National Bone Health Alliance (NBHA) will execute a project to help assure health professionals of the clinical utility of bone turnover markers; the current clinical approaches concerning osteoporosis and the status and use of bone turnover markers in the USA; the rationale for focusing this effort around two specific bone turnover markers; the need to standardize bone marker sample collection procedures, reference ranges, and bone turnover marker assays in clinical laboratories; and the importance of harmonization for future research of bone turnover markers. Osteoporosis is a major global health problem, with the prevalence and incidence of osteoporosis for at-risk populations estimated to be 44 million Americans. The potential of bone markers as an additional tool for health care professionals to improve patient outcomes and impact morbidity and mortality is crucial in providing better health care and addressing rising health care costs. This need to advance the field of bone turnover markers has been recognized by a number of organizations, including the International Osteoporosis Foundation (IOF), National Osteoporosis Foundation, International Federation of Clinical Chemistry, and Laboratory Medicine (IFCC), and the NBHA. This position paper elucidates how this project will standardize bone turnover marker sample collection procedures in the USA, establish a USA reference range for one bone formation (serum procollagen type I N propeptide, s-PINP) and one bone resorption (serum C-terminal telopeptide of type I collagen, s-CTX) marker, and standardize bone turnover marker assays used in clinical laboratories. This effort will allow clinicians from the USA to have confidence in their use of bone turnover markers to help monitor osteoporosis treatment and assess future fracture risk. This project builds on the recommendations of the IOF/IFCC Bone Marker Standards Working Group by developing USA reference standards for s-PINP and s-CTX, the markers identified as most promising for use as reference markers. The goals of this project will be realized through the NBHA and will include its governmental, academic, for-profit, and non-profit sector stakeholders as well as major academic and commercial laboratories. Upon completion, a parallel effort will be pursued to make bone turnover marker measurements reliable and accepted by all health care professionals for facilitating treatment decisions and ultimately be reimbursed by all health insurance payers. Successful completion of this project will help assure health professionals from the USA of the clinical utility of bone turnover markers and ties in with the parallel effort of the IOF/IFCC to develop worldwide bone turnover reference ranges.
    Osteoporosis International 07/2012; 23(10):2425-33. · 4.04 Impact Factor
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    ABSTRACT: Antecedentes: Nuestro objetivo fue evaluar la exactitud en el score de la clasificación del riesgo de enfermedad cardiovascular (ECV) por parte de la medida directa de colesterol de LDL (dc-LDL), del cálculo del colesterol LDL (cc-LDL), y del colesterol no HDL (no-c-HDL) en comparación a la clasificación por los métodos de referencia (MR) realizados en el CDC. Métodos: Se estudiaron 175 pacientes, entre ellos 138 con ECV u otras condiciones que puedan afectar a la medición de c-LDL. Las mediciones de dc-LDL se realizaron con reactivos Denka, Kyowa, Sekisui, Serotec, Sysmex, UMA y Wako. Se calculó cc-LDL mediante la ecuación de Friedewald, usando la respectiva medida directa del colesterol de HDL de cada fabricante y las mediciones de colesterol total y triglicéridos medidas por Roche y Siemens (Advia), respectivamente. Resultados: Para los participantes con triglicéridos <2,26 mmol / L (<200 mg / dL), la tasa de errores de clasificación global en el score de riesgo de ECV fue de 5% a 17% con los métodos de cc-LDL, y del 8% al 26% para los métodos dc-LDL en comparación con los MR. Sólo el dc-LDL realizado por Wako presentó menos errores de clasificación que su método de cc-LDL correspondiente (8% vs 17%, p<0,05). El no-c-HDL clasificó erróneamente a un menor número de pacientes que dc-LDL en 4 de los 8 métodos (P <0,05). Para los pacientes con triglicéridos >2,26 mmol / L (>200 mg / dL) y <4,52 mmol / L (<400 mg / dL), los métodos de dc-LDL, en general, presentaron mejores resultados que los métodos cc-LDL, y los métodos de no-c-HDL mostraron una mejor correspondencia con el MR en el score de clasificación de riesgo de ECV que los métodos de dc-LDL como de cc-LDL. Conclusiones: A excepción de las personas hipertrigliceridémicas, 7 de los 8 métodos de dc-LDL fallaron en mejorar el score de clasificación de riesgo de ECV sobre los correspondientes métodos de cc-LDL. No-c-HDL mostró en general la mejor concordancia con el MR en el score de clasificación de riesgo de ECV en individuos normales y con hipertrigliceridemia.
    Acta bioquímica clínica latinoamericana 12/2011; 45(4):773-784. · 0.09 Impact Factor
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    ABSTRACT: Our objective was to evaluate the accuracy of cardiovascular disease (CVD) risk score classification by direct LDL cholesterol (dLDL-C), calculated LDL cholesterol (cLDL-C), and non-HDL cholesterol (non-HDL-C) compared to classification by reference measurement procedures (RMPs) performed at the CDC. We examined 175 individuals, including 138 with CVD or conditions that may affect LDL-C measurement. dLDL-C measurements were performed using Denka, Kyowa, Sekisui, Serotec, Sysmex, UMA, and Wako reagents. cLDL-C was calculated by the Friedewald equation, using each manufacturer's direct HDL-C assay measurements, and total cholesterol and triglyceride measurements by Roche and Siemens (Advia) assays, respectively. For participants with triglycerides<2.26 mmol/L (<200 mg/dL), the overall misclassification rate for the CVD risk score ranged from 5% to 17% for cLDL-C methods and 8% to 26% for dLDL-C methods when compared to the RMP. Only Wako dLDL-C had fewer misclassifications than its corresponding cLDL-C method (8% vs 17%; P<0.05). Non-HDL-C assays misclassified fewer patients than dLDL-C for 4 of 8 methods (P<0.05). For participants with triglycerides≥2.26 mmol/L (≥200 mg/dL) and<4.52 mmol/L (<400 mg/dL), dLDL-C methods, in general, performed better than cLDL-C methods, and non-HDL-C methods showed better correspondence to the RMP for CVD risk score than either dLDL-C or cLDL-C methods. Except for hypertriglyceridemic individuals, 7 of 8 dLDL-C methods failed to show improved CVD risk score classification over the corresponding cLDL-C methods. Non-HDL-C showed overall the best concordance with the RMP for CVD risk score classification of both normal and hypertriglyceridemic individuals.
    Clinical Chemistry 01/2011; 57(3):490-501. · 7.15 Impact Factor
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    ABSTRACT: A randomized, double-blind, placebo-controlled study assessed the efficacy of acetaminophen or fluvastatin in preventing post-dose symptoms (increases in body temperature or use of rescue medication) following a single infusion of the intravenous (IV) bisphosphonate zoledronic acid (ZOL). Acetaminophen, but not fluvastatin, significantly reduced the incidence and severity of post-dose symptoms. Transient symptoms including myalgia and pyrexia have been reported post-infusion of IV bisphosphonates, typically starting the day after infusion and resolving within several days. The cause is unknown but may be related to transient cytokine elevations. Statins' potential to block release of these cytokines has been hypothesized. This study was aimed to evaluate efficacy of acetaminophen and fluvastatin in preventing/reducing post-dose symptoms following ZOL 5 mg infusion. Randomized, double-blind, placebo-controlled study of efficacy of acetaminophen or fluvastatin in preventing increases in body temperature or use of rescue medication (ibuprofen) following a single ZOL infusion. Bisphosphonate-naive postmenopausal women with low bone mass (N = 793) were randomized into three treatment groups and given 650 mg acetaminophen or 80 mg fluvastatin or placebo 45 min before ZOL infusion. The acetaminophen group continued taking 650 mg acetaminophen every 6 h over the next 3 days, and the other two groups took matching placebo according to the same schedule. Subjects recorded body temperature, symptoms in a diary. Inflammatory cytokines and C-reactive protein (CRP) were measured at baseline, 24, and 72 h in a study subset. Acetaminophen four times/day significantly reduced the incidence and severity of post-dose symptoms following ZOL infusion. Single-dose fluvastatin 80 mg prior to ZOL infusion did not prevent/reduce post-dose symptoms. Cytokine levels increased by 24 h and returned towards baseline by 72 h, similar to the pattern for post-infusion symptoms. CRP levels increased from baseline to 72 h. Acetaminophen four times/day for 3 days significantly reduced the incidence and severity of post-dose symptoms following ZOL infusion.
    Osteoporosis International 11/2010; 22(8):2337-45. · 4.04 Impact Factor
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    ABSTRACT: Methods from 7 manufacturers and 1 distributor for directly measuring HDL cholesterol (C) and LDL-C were evaluated for imprecision, trueness, total error, and specificity in nonfrozen serum samples. We performed each direct method according to the manufacturer's instructions, using a Roche/Hitachi 917 analyzer, and compared the results with those obtained with reference measurement procedures for HDL-C and LDL-C. Imprecision was estimated for 35 runs performed with frozen pooled serum specimens and triplicate measurements on each individual sample. Sera from 37 individuals without disease and 138 with disease (primarily dyslipidemic and cardiovascular) were measured by each method. Trueness and total error were evaluated from the difference between the direct methods and reference measurement procedures. Specificity was evaluated from the dispersion in differences observed. Imprecision data based on 4 frozen serum pools showed total CVs <3.7% for HDL-C and <4.4% for LDL-C. Bias for the nondiseased group ranged from -5.4% to 4.8% for HDL-C and from -6.8% to 1.1% for LDL-C, and for the diseased group from -8.6% to 8.8% for HDL-C and from -11.8% to 4.1% for LDL-C. Total error for the nondiseased group ranged from -13.4% to 13.6% for HDL-C and from -13.3% to 13.5% for LDL-C, and for the diseased group from -19.8% to 36.3% for HDL-C and from -26.6% to 31.9% for LDL-C. Six of 8 HDL-C and 5 of 8 LDL-C direct methods met the National Cholesterol Education Program total error goals for nondiseased individuals. All the methods failed to meet these goals for diseased individuals, however, because of lack of specificity toward abnormal lipoproteins.
    Clinical Chemistry 04/2010; 56(6):977-86. · 7.15 Impact Factor
  • Labmedicine. 01/2008; 39(8):481-490.

Publication Stats

59 Citations
22.47 Total Impact Points

Institutions

  • 2010–2012
    • Pacific Biomarkers
      Seattle, Washington, United States
    • Virginia Commonwealth University
      • Department of Pathology
      Richmond, Virginia, United States
    • University of California, Los Angeles
      Los Angeles, California, United States
  • 2011
    • National Institutes of Health
      • Department of Laboratory Medicine
      Bethesda, MD, United States