Standardization of high-sensitivity immunoassays for measurement of C-reactive protein; II: Two approaches for assessing commutability of a reference material.

Background: We evaluated the commutability of a proposed reference material (PRM), with a formulation based on dilution of Certified Reference Material 470 (CRM470), for 24 high-sensitivity C-reactive protein (hsCRP) methods. We also investigated whether calibration by use of PRM was effective in harmonizing results.

Methods: A set of 40 native clinical samples was measured along with PRM and 3 dilutions of PRM.

Performance evaluation of the ADVIA Centaur anti-HBe and HBeAg assays.

Background: Detection of HBeAg and anti-HBe is valuable for the evaluation and therapeutic management of hepatitis B infection.

Objectives: To determine the clinical performance of the newly CE-approved(a) HBeAg and anti-HBe assays on the fully automated, random access ADVIA Centaur immunoassay system.

Study Design: Patient samples collected at two sites were used to compare the ADVIA Centaur assays to Abbott AxSYM assays.

Glycogen phosphorylase BB in acute coronary syndromes.

The diagnosis of myocardial damage is preferably based on measurement of the cardiac-specific troponins. However, there is an emerging need for early, specific cardiac markers. One potential candidate is the glycogen phosphorylase BB isoenzyme (GPBB).

First WHO/IFCC International Reference Reagent for Lipoprotein(a) for Immunoassay--Lp(a) SRM 2B.

Lipoprotein(a) is an important predictor of cardiovascular disease risk. The lack of internationally accepted standardization has impeded the broad application of this lipoprotein in laboratory medicine. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), through its Working Group on Lipoprotein(a) and together with research institutions and several diagnostic companies, have succeeded in developing an international reference material that is intended for the transfer of a lipoprotein(a) concentration to manufacturers' master calibrators.

European performance evaluations of the ADVIA Centaur infectious disease assays: requirements for performance evaluation according to the European directive on in vitro diagnostics.

The following article reports on newly developed ADVIA Centaur immunoassays (Bayer HealthCare LLC, Diagnostics Division; Tarrytown, NY, USA) for the detection of markers of hepatitis B infection in human serum and plasma. These fully automated assays detect antibodies to hepatitis B surface antigen (anti-HBs), total antibodies to hepatitis B core antigen (anti-HBc Total) and IgM antibodies to hepatitis B core antigen (anti-HBc IgM). The ADVIA Centaur HBV assays employ magnetic particle separation technology with direct chemiluminescence for optimal assay performance.

An update on laboratory productivity with infectious disease assays on the Bayer ADVIA Centaur Immunoassay System.

New biological materials and advances in robotic and computer technologies have enabled the development of automated systems designed for high-performance infectious disease immunoassays and nucleic acid amplification. The fully automated, random access Bayer ADVIA Centaur immunoassay system, offering testing for fertility, therapeutic drug monitoring, infectious disease, allergy, cardiovascular, anemia, oncology, TDMs and thyroid, has been specifically designed for use in large-volume laboratories. New immunoassay tests have been developed for the ADVIA Centaur for the hepatitis A virus, hepatitis B virus, hepatitis C virus and HIV.

Standardization of immunoassays for measurement of myoglobin in serum. Phase I: evaluation of candidate secondary reference materials.

Background: Myoglobin is a low-molecular weight protein present in the cytosol of striated muscles. Its concentrations in serum can be measured by immunoassays and are used as an early indicator of myocardial necrosis. Since variability among commercial myoglobin assays exists, standardization of myoglobin assays is needed.

Evaluation of imprecision for cardiac troponin assays at low-range concentrations.

Background: The European Society of Cardiology/American College of Cardiology Committee for the Redefinition of Myocardial Infarction (MI) has recommended that an increased cardiac troponin should be defined as a measurement above the 99th percentile value of the reference group. A total imprecision (CV) at the decision limit of View Article and Find Full Text PDF

The new European directive on in vitro diagnostics.

The Directive on in vitro Diagnostic Medical Devices (IVDD 98/79/EC) was officially adopted by the European Union (EU) on December 7, 1998. The IVDD aims to supplement the legal framework of the European Community, which governs the conditions for the placing on the market of medical devices, by extending the already implemented legislation to the category of in vitro diagnostic medical devices (IVDs). They consist of those devices, including reagents and reagent products, calibrator materials or instruments, as well as specimen receptacles, intended by the manufacturer for the in vitro analysis of specimens derived from the human body.

Standardization of immunoassays for measurement of high-sensitivity C-reactive protein. Phase I: evaluation of secondary reference materials.

Background: Inflammation contributes to the development and progression of atherosclerosis, and C-reactive protein (CRP) can be used as a marker to assess risk for cardiovascular diseases. As variability among existing high-sensitivity CRP (hsCRP) assays can lead to misclassification of patients and hamper implementation of population-based medical decision points, standardization of hsCRP assays is needed.

Methods: We evaluated five proposed secondary reference materials, including two diluted preparations of Certified Reference Material 470 (CRM470), two preparations of a serum-based material with recombinant CRP added, and one serum-based material with isolated CRP added.

Reference Materials for the Standardization of the Apolipoproteins A-I and B, and Lipoprotein(a).

Measurement of the apolipoproteins A-I and B, and lipoprotein(a) enable identification of individuals at increased risk of cardiovascular disease. However, the lack of standardized methods to measure these risk markers has resulted for many years in the non-comparability of values and often a conflicting interpretation of clinical studies. Due to the collaborative efforts of the International Federation of Clinical Chemistry and Laboratory Medicine, research organizations, clinical chemistry laboratories and diagnostic companies, secondary reference materials for the apolipoproteins A-I and B, and lipoprotein(a) have been prepared and tested for their ability to harmonize test values.