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Meyer Z.C.,Amphia Hospital | Schreinemakers J.M.J.,Amphia Hospital | Mulder P.G.H.,Amphia Academy | De Waal R.A.L.,Amphia Hospital | And 2 more authors.
Journal of Surgical Research | Year: 2013

Background: The purpose of this study is first to assess the clinical value of lactate concentrations by comparison with clinical scoring systems, and second to determine the value of lactate levels in clinical decisions as ordering diagnostic and therapeutic (re)interventions in the population of critically ill surgical patients on the intensive care unit (ICU). Materials and methods: From April 2010 to June 2011, the L-lactate concentrations, Sequential Organ Failure Assessment (SOFA) score and Acute Physiological and Chronic Health Evaluation II (APACHE II) score were prospectively collected in surgical patients (n = 174) admitted into the ICU. The L-Lactate and scoring systems were related to events defined as performing computed tomography-scans, laparotomy, ultrasonography, and flexible endoscopy. Furthermore, all surgical complications were also registered. Results: For SOFA scores above four points, mean lactate concentrations increased 4.5% for each point increase in SOFA score (P < 0.0005). In APACHE II scores above 16 points, mean lactate concentrations increased 2.9% for each point increase in APACHE II score (P < 0.0005). Each 10% increase in lactate concentration showed a 3.3% higher odds for a first event (OR 1.033; P = 0.26). Lactate levels did not correspond with more complications (OR 0.968; P = 0.52). Conclusions: There is a significant positive relationship between lactate concentrations, high SOFA scores, and APACHE II scores. However, the important outcome is that lactate seems to be a poor predictor for surgical complications in the critically ill surgical patient in the ICU. © 2013 Elsevier Inc. All rights reserved. Source

Bots M.,University of Amsterdam | Stroobants A.K.,University of Amsterdam | Delzenne B.,University of Amsterdam | Soeters M.R.,University of Amsterdam | And 6 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2015

Background: Haemoglobin (Hb) variants are well-known factors interfering with accurate HbA1c testing. This report describes two novel Hb variants leading to inappropriate quantification of HbA1c by ion-exchange chromatography. Methods: Glycated forms of novel Hb variants were recognised in the blood of two patients with diabetes mellitus screened by HbA1c ion-exchange chromatography. Dedicated high-resolution cation-exchange chromatography and subsequent DNA sequencing revealed the exact nature of the variants. Other common techniques for quantifying HbA1c were applied on both samples and haematological parameters were determined to judge possible pathology associated with the novel Hb variants. Results: A fraction of 15% of abnormal Hb was observed in a 37-year-old female. DNA sequencing revealed a heterozygous mutation in the α1-globin gene, resulting in a leucine-to-phenylalanine amino-acid substitution (HBA1: c.301C>T, p.Leu101Phe). We named this variant Hb Weesp. The other novel variant, Hb Haelen, presented as a 40% fraction in a 63-year-old male and resulted from a heterozygous amino acid substitution in the β-globin gene (HBB: c.335T>C, p.Val112Gly). The presence of both Hb variants resulted in aberrant separation of the Hb components, leading to an inadequate quantification of HbA1c. Conclusions: Close examination of HbA1c chromatograms revealed two novel, clinically silent Hb variants that interfere with HbA1c quantification. Healthcare providers need to be aware of the potential of such Hb variants when interpreting HbA1c results. © 2015 by De Gruyter. Source

Van Rossum A.P.,Laboratory for Clinical Chemistry and Hematology | Gunnewiek J.K.,Radboud University Nijmegen | Verheijen F.M.,Laboratory for Clinical Chemistry | Vlasveld L.T.,Bronovo Hospital | And 2 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2011

Background: Plasma vitamin B12 wcobalamin (Cbl)x concentrations are usually measured as a screening marker for vitamin B12 deficiency. Siemens Healthcare Diagnostics has introduced Cbl assays for various platforms, i.e., the immulite (IML) 2000 and 2500. In our laboratories, regular validation studies for the IML 2500 were conducted and showed acceptable quality specifications. After the introduction of the IML 2500 Cbl assay, clinicians in the department of internal medicine reported an increased frequency of patients with Cbl-concentrations less than 148 pmol/L. Methods: In order to investigate this claim from the clinicians, we retrospectively analyzed the internal and external quality control (QC) of the Cbl assay. In addition, the monthly patient means for the Cbl assay were analyzed both before and after the introduction of the new Cbl assay. Results: No abnormalities were found in the internal and external QCs. However, the monthly patient means for the Cbl assay showed a statistically significant decrease in cobalamin concentrations. Siemens acknowledged the problems and formulated a new Cbl assay, which was subsequently validated in our laboratories and showed equivocal Cbl results when compared to the IML 2000 Cbl assay. Conclusions: We report a flawed validation study conducted by the manufacturer that resulted in an undetected analytical problem in the IML 2500 Cbl assay, its subsequent introduction on the market, the final recognition of the poor performance of the assay by our clinicians, and the eventual resolution by the manufacturer. Hence, it emphasizes the utmost importance for thorough comparison between assays over the entire measurement range, even when both assays are produced by the same manufacturer. © 2011 by Walter de Gruyter. Source

Hessels J.,Laboratory for Clinical Chemistry | Douw G.,Laboratory for Clinical Chemistry | Yildirim D.D.,Laboratory for Clinical Chemistry | Meerman G.,Laboratory for Clinical Chemistry | And 2 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2012

Background: Tests for fecal calprotectin are usually either enzyme-linked immunosorbent assays (ELISA) or a timeresolved fluorimetric immunoassay (TRFIA). These timeconsuming tests are performed only once every 1 or 2 weeks. Before the results of the tests are known most patients have already undergone colonoscopy. A rapid test, performed on outpatients, could minimize the number of necessary colonoscopies. To establish optimal cut-off values minimizing the necessity for colonoscopies, we compared two commercially available rapid tests with a quantitative TRFIA. Methods: Fecal samples were collected from 85 patients with lower gastrointestinal complaints. Calprotectin was measured using quantitative TRFIA as well as using two rapid tests: Prevent ID CalDetect and Quantum Blue calprotectin. We used the TRFIA method as the golden standard with a cut-off value of 50 μ g/g. The percentage correct classification, sensitivity, specificity and positive and negative predictive value were calculated for both rapid tests at various cut-off levels. Results: Correlation between both of the rapid tests with TRFIA was significant. Quantum Blue calprotectin (κ 0.77) correlated better than Prevent ID CalDetect (κ 0.46). Optimal cut-off levels for Prevent ID CalDetect and Quantum Blue calprotectin rapid tests were 15 μ g/g and 40 μ g/g with a reduction in the number of necessary colonoscopies of 39 % and 62%, respectively. Conclusions: The Quantum Blue calprotectin rapid test demonstrated better analytical performance than the Prevent ID CalDetect in reducing the number of colonoscopies. Furthermore, the former test has the advantage of using a point of care reader for quantitative measurement and for establishing an optimal cut-off level. © 2012 by Walter de Gruyter ·Berlin · Boston. Source

Wieland C.W.,Laboratory for Clinical Chemistry | Vogl T.,University of Munster | Vogl T.,The Interdisciplinary Center | Ordelman A.,Laboratory for Clinical Chemistry | And 7 more authors.
British Journal of Dermatology | Year: 2013

Background Hidradenitis suppurativa (HS) is a chronic inflammatory and debilitating disease of the skin. No biomarkers for this disease exist. Objectives We set out to test whether angiotensin-converting enzyme (ACE), lysozyme, soluble interleukin 2 receptor (sIL-2R) and S100A8/A9 (calprotectin) are elevated in patients with HS. Methods Serum was collected from 29 patients with HS at different stages of the disease, and from 51 controls. ACE, lysozyme, sIL-2R and S100A8/A9 levels were measured. Clinical observation of disease activity was scored according to the Hurley grading system and by a physician global score (PGS) of disease severity. Results Serum levels of lysozyme and ACE were not increased above the normal reference values in controls or patients with HS. Levels of sIL-2R and S100A8/A9 were significantly higher in patients with HS than in controls (P < 0·001 for both sIL-2R and S100A8/A9). Based on the receiver operating characteristic curves, the optimum sIL-2R and S100A8/A9 cut-off values were 375 U mL-1 and 680 ng mL-1, respectively, with a sensitivity of 0·79 and specificity of 0·78 for sIL-2R, and 0·86 and 0·88, respectively, for S100A8/A9. No correlations with Hurley classification scores were found. However, when using PGS of disease activity to categorize patients, levels of S100A8/A9, but not sIL-2R, tended to be higher in patients with more active disease. Conclusions Levels of S100A8/A9 and sIL-2R, but not ACE or lysozyme, are elevated in the serum of patients with HS. However, there is no correlation between S100A8/A9 or sIL-2R levels and disease stage according to the Hurley classification system. Further research is needed to study the potential of S100A8/A9 to score disease activity in larger cohorts of patients and to predict disease flares. What's already known about this topic? Hidradenitis suppurative (HS) is a chronic inflammatory and debilitating disease of the skin. Currently, no biomarkers for HS exist. What does this study add? This study indicates that soluble interleukin 2 receptor and S100A8/A9 are potential serum biomarkers of HS. S100A8/A9 is also a marker of disease activity. See also the Commentary by Jemec © 2013 The Authors. BJD © 2013 British Association of Dermatologists. Source

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