Prime time for enzymatic creatinine methods in pediatrics.

Background: The literature regarding the nonspecificity of applications of the Jaffe (alkaline picrate) reaction for creatinine is generally outdated. We conducted a specificity study to update the nonspecificity information for current Jaffe and enzymatic creatinine assays.

Methods: Two serum pools with creatinine concentrations within the pediatric reference interval were spiked with albumin, IgG, unconjugated bilirubin, adult hemoglobin (Hb A), and fetal hemoglobin (Hb F) to produce 1 unspiked and 5 spiked samples per pool.

Trueness verification and traceability assessment of results from commercial systems for measurement of six enzyme activities in serum: an international study in the EC4 framework of the Calibration 2000 project.

Background: The in vitro diagnostics directive of the European Union requires traceability to higher order reference measurement procedures and materials for analytes in assuring the result trueness and comparability of laboratory measurements. Manufacturers must ensure that the systems they market are calibrated against available reference systems. Validation of metrologically traceable calibrations is, however, required.

Change in serum albumin and subsequent decline in functional status in older persons.

Background And Aims: This study examines whether a three-year change in serum albumin concentration is associated with subsequent decline in functional status in older persons.

Methods: A total of 588 participants from the Longitudinal Aging Study Amsterdam aged 65-85 years were followed for six years. The three-year change in serum albumin was classified in four groups: chronic low (< or =43 g/L at both time points), decrease (decrease of 2.

External Quality Assessment in The Netherlands: time to introduce commutable survey specimens. Lessons from the Dutch "Calibration 2000" project.

The performance of suitable secondary reference material for the use of trueness control of six routinely measured clinical enzymes in the Dutch External Quality Assessment (EQA) scheme is described. The reference material of choice was selected using the split-patient-sample between-field method (twin study) design as described in an earlier study of the Calibration 2000 project in The Netherlands. This material, which was proven to be commutable for all wet chemistry systems, was implemented as the national enzyme calibrator.