[Laboratory errors – why the laboratory is not (always) to blame].

More than half of the so called "laboratory errors" has already happened before the analysis starts in the laboratory and many mistakes are made after the analysis itself. Pre- and post-analytical errors cause 60 to 90 % of all unexpected or erroneous values; only 10 to 15 % are caused by analytical problems. Internal quality control and external quality assessments are a matter of course today while standardisation still could be improved.

Increased sensitivity in detecting renal impairments by quantitative measurement of marker protein excretion compared to detection of pathological particles in urine sediment analysis.

Background: Positive test strip results, pathological particles in urine and the presence of proteinuria are common findings in nephropathies. A comparison between these methods and renal biopsies became available with the introduction of quantitative measurement of marker proteins (albumin, transferrin, IgG, alpha(1)-microglobulin, retinol binding protein, alpha(2)-macroglobulin, Bence Jones proteins) and standardised urine sediment analysis by flow cytometry or microscopy.

Methods: A total of 400 urine samples were examined using marker protein patterns, test strips and quantitative sediment analyses.

Effective control of persistent hyperparathyroidism with cinacalcet in renal allograft recipients.

Background: Cinacalcet rapidly normalizes serum calcium and reduces intact parathyroid hormone (PTH) levels in renal transplant patients with hypercalcaemia and persistent hyperparathyroidism. The aim of this study is to evaluate the 6 months efficacy of cinacalcet and the effect of cinacalcet withdrawal on serum calcium and PTH in such patients. Furthermore, the impact of cinacalcet on bone turnover and quality of life was assessed.

New "plasma referenced" POCT glucose monitoring systems--are they suitable for glucose monitoring and diagnosis of diabetes?

Background: Results from portable glucose meters should be reported as plasma values as recommended by IFCC. Three new "plasma calibrated" blood glucose meters (Abbott Precision Xcceed, Bayer Ascensia Contour and Roche Accu-Chek Aviva) were compared against laboratory venous plasma glucose measurements to determine their suitability for patient monitoring and diabetes diagnosis.

Methods: 115 capillary blood samples were analyzed on each of the three meters and compared to venous plasma measurements on the Dade Behring RXL analyzer (Hexokinase method).

Diagnostic efficiency of different amphetamine screening tests--the search for an optimal cutoff.

Increased use of designer drugs (amphetamines and amphetamine-like substances) raises the need for fast screening tests in urine in clinical settings, workplace and drug rehabilitation. Immunological assays currently used are subject to unwanted crossreactivities, partly depending on the cutoff concentrations used. The values recommended in Europe and the USA are 500 and 1000 ng/ml, respectively.

An automated 'bio-intact' PTH assay: a step towards standardisation and improved correlation with parathyroid function in renal disease.

Background: Most methods for the determination of parathyroid hormone (PTH) show cross-reactivity with N-truncated forms of PTH. The analytic and diagnostic value of a recently developed automated PTH test without this cross-reactivity was examined.

Methods: The PTH levels of 73 patients undergoing hemodialysis were compared using the 'bio-intact' PTH (Nichols Institute Diagnostics) and 3 'intact' PTH tests (from Nichols, Roche Elecsys and Diagnostics Corporation DPC).