SummaryStudies measuring the fibrin degradation product D-Dimer (DD) using enzyme-linked immunosorbent assays (ELISA) in patients with venographically proven deep venous thrombosis (DVT) suggest that it is possible to exclude DVT when DD level is below a certain cut-off level. However, ELISA methods are time-consuming and not available in all laboratories. Different rapid latex-agglutination assays have been investigated, but their sensitivity is considerably lower.In the present study we compared the value of four novel latex DD tests (Tinaquant®, Minutex®, Ortho® and SimpliRed®) and one rapid ELISA (VIDAS®) to a classical ELISA DD assay (Organon Mab Y18®) in 132 patients suspected of DVT.The VIDAS®, a new quantitative automated ELISA, had a sensitivity of 100% and a negative predictive value of 100% for both proximal and distal DVT at a cut-off level of 500 ng/ml. The Tinaquant® assay, a new quantitative latex method, had a sensitivity of 99% and a negative predictive value of 93% for both proximal and distal DVT at a cut-off level of 500 ng/ml. For proximal DVT only, both assays had a sensitivity and negative predictive value of 100%. VIDAS® and Tinaquant® correlated well with ELISA (correlation of r = 0.96 and r = 0.98 respectively). Sensitivities of the semi-quantitative latex assays Minutex®, Ortho® and SimpliRed® were considerably lower (77%, 51 % and 61 % respectively).These results suggest that VIDAS® and Tinaquant® may be used instead of ELISA DD in the exclusion of DVT. Tinaquant® can be performed within 20 min and VIDAS® within 35 min. Both assays might be used as a routine screening test and should be evaluated in large clinical management studies.

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Background and purpose: Aspirin reduces the risk of myocardial infarction and stroke by inhibiting thromboxane production in platelets. This inhibition can be competitively antagonized by some non-steroidal anti-inflammatory drugs (NSAIDs). Experimental approach: By measuring thromboxane B2 production in healthy volunteers, we investigated whether ibuprofen (800 mg three times daily for 7 days) or diclofenac (50 mg three times daily for 7 days) taken concurrently with aspirin 80 mg (once daily for 7 days) influenced the inhibitory effect of aspirin. The effects were compared with aspirin 30 mg (once daily for 7 days), which is the lowest dose of aspirin with a proven thromboprophylactic effect. Key results: The median percentage inhibition of thromboxane B2 levels by 30 mg or 80 mg aspirin was 90.3% (range 83.1-96.0%) and 98.0% (range 96.8-99.2%) respectively. The inhibition by concurrent administration of slow release diclofenac and 80 mg aspirin was 98.1% (range 97.2-98.9%), indicating no interference between aspirin and diclofenac. The inhibition decreased significantly by concurrent administration of immediate release ibuprofen and 80 mg aspirin (86.6%; range 77.6-95.1%) to a level less than 30 mg aspirin. Conclusions and implications:As alternatives are easily available, NSAIDs such as diclofenac should be preferred to ibuprofen for combined use with aspirin.

Procalcitonin (PCT) is a 13-kDa peptide and a precursor of calcitonin. In a healthy population, PCT concentrations are negligible (1 ). In systemic bacterial and fungal infections, plasma concentrations are raised, whereas concentrations remain fairly low in infections of viral or nonspecific cause (2 ). Recent studies have demonstrated the potential of PCT as a parameter to guide antibiotic therapy in different groups of patients, i.e., patients with chronic obstructive pulmonary disease experiencing respiratory tract infections (3,4 ). The most frequently used medical decision points at which the use of antibiotic therapy is considered are 0.25 g/L and 0.50 g/L, depending on the patient population (3, 4 ).The first PCT assays were based on manual immunochemistry methods (Brahms PCT LIA). These assays have been replaced by fully automated immunochemistry methods (Brahms Kryptor, Brahms LIAISON, Olympus SphereLight 180). Recently, the PCT assay has been modified for use on a consolidated routine immunochemistry analyzer family, the Roche Elecsys, cobas, and the Roche Modular E170 systems. We evaluated the analytical performance of this new assay by following the EP10 protocol, a document from the Clinical and Laboratory Standards Institute to test precision, linearity, recovery, carryover, and drift. Samples were prepared at different concentrations, from 0.24 -2.85 g/L. Three aliquots of each concentration were assayed on 5 different days, in a specific assay order. The within-run CV ranged from 3.0% for the lowest concentration to 1.3% for the highest concentration. The between-day CV ranged from 6.3% for the lowest concentration to 2.8% for the highest. These levels of imprecision were comparable with those reported for the PCT assay on the Brahms Kryptor (5 ). The mean recovery was 99%. There was no evidence of nonlinearity or sample carryover. The limit of quantification, i.e., the lowest concentration of analyte that can be quantified with a between-run imprecision of Ͻ20%, met the manufacturer's specification of 0.06 g/L. In addition, we compared the new PCT assay from Roche on the Modular 170 with the widely accepted PCT assay from Brahms on the Kryptor (5 ). For analytical comparison, we used 229 samples of patient serum obtained from 195 different patients who were admitted to our hospital for lower respiratory tract infections (81, exacerbation of chronic obstructive pulmonary disease; 114, pneumonia). The patients participated in an ongoing study in our hospital on the etiology of exacerbations of chronic obstructive pulmonary disease, a study approved by the local ethics committee. Samples were also collected from 34 patients after antibiotic treatment. The majority of the serum samples were obtained within 24 h of admission. Samples not immediately analyzed were stored at Ϫ80°C until analysis. PCT concentrations ranged from 0.02 g/L (limit of detection, i.e., the lowest concentration of analyte that can be reliably measured as being qualitatively present in the sample) to 57 g/L. PCT concentrations...

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