BACKGROUND Monitoring whole-blood concentrations of cyclosporin A (CsA) is common practice in the management of solid organ and bone marrow transplant recipients. In a multicenter study we evaluated a new, direct (no pretreatment) CsA assay on the Dade Behring Dimension RxL system and compared results with those from the Abbott TDx CsA immunoassay and a HPLC method. METHODS Whole-blood sample...

OBJECTIVE To compare troponin I levels in plasma before and after specimen recentrifugation. METHODS Over a period of 24 consecutive days, we recentrifuged 189 plasma specimens in which the troponin I level was higher than the positivity cut off (60 ng/L) and then remeasured the troponin I. RESULTS Two-tailed Wilcoxon matched-pairs test results identified a statistically significant differe...

BACKGROUND The principle of the erythrocyte sedimentation rate (ESR) as assessed by TEST 1 is different from that of Westergren-based methods. This could result in different influences on the tests by paraproteins. METHODS We investigated the effect of paraproteins on ESR readings by TEST 1 (y) and the StarrSed (x), a Westergren-based method, in 142 patients with paraproteinaemia. Agreement (...

BACKGROUND Mycophenolic acid (MPA) is an immunosuppressant for which therapeutic drug monitoring (TDM) is performed for optimal prophylaxis and avoidance of toxicity in transplant patients. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is ideally suited for TDM of MPA. There have been several method comparisons of the Roche Total MPA assay, but none have been performed with respect ...

BACKGROUND Cystatin C is increasingly used in glomerular filtration rate (GFR) estimation equations. The dependence of cystatin C results upon the analytical method has been a major source of controversy. METHODS Cystatin C was measured with non-standardized turbidimetric Roche Generation 1 and standardized nephelometric Siemens assays in 3666 and additionally with standardized Roche Generati...

PURPOSE The PROTIA™ Allergy-Q® enzyme immunoassay (EIA) is a recently developed screening assay for specific immunoglobulin E (sIgE) for multiple allergens. The ImmunoCAP® fluorescent EIA (FEIA) system is the most widely used method for sIgE detection. In this study, we evaluated the performance of the Allergy-Q® system compared to the ImmunoCAP® system. METHODS We compared the 2 systems usin...

Serum concentrations of cancer antigen (CA) 19-9 can be useful in monitoring response to therapy in pancreatic cancer. The objective of this study was to evaluate 5 automated CA 19-9 assays: ARCHITECT 12000 (Abbott Diagnostics, Abbott Park, IL), ADVIA Centaur (Bayer Diagnostics, Tarrytown, NY), UniCel Dxl 800 (Beckman Coulter, Fullerton, CA), IMMULITE 2000 (Diagnostic Products, Los Angeles, CA)...

A new LC-MS/MS method with simple sample extraction and a relatively short period of vancomycin analysis for routine therapeutic drug monitoring was developed and validated. 50μL serum was precipitated using 20μL 33% trichloroacetic acid and 0.5mol/L NH4OH was added to increase pH before analysis. A RP BEH C18, 1.7μm, 2.1×50mm column maintained at 30°C and tobramycin as internal standard were u...

The measurement of circulating prealbumin has been shown to be clinically useful in the assessment of nutritional status, both as an initial screen and in the monitoring of nutritional recovery. We describe a fully automated, noncompetitive, homogeneous, light-scattering immunoassay that has been developed for this analyte on a Dimension (Dade) analyzer. A sheep anti-prealbumin IgG fraction was...

BACKGROUND Retinol Binding Protein 4 (RBP4) is an exciting new biomarker for the determination of insulin resistance and type 2 diabetes. It is known that circulating RBP4 resides in multiple variants which may provide enhanced clinical utility, but conventional immunoassay methods are blind to such differences. A Mass Spectrometric immunoassay (MSIA) technology that can quantitate total RBP4 a...