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Oremek G.M.,Goethe University Frankfurt | Oertl A.,Goethe University Frankfurt | Bertsch T.,Klinikum Nurnberg Institute For Klinische Chemie | Bewarder N.,BIOREF GmbH | And 22 more authors.
Clinical Laboratory | Year: 2011

Background: The present proficiency study aimed to elucidate the comparability and reliability of test systems for the determination of AFP concentrations. Methods: 25 laboratories using 8 different commercial test systems used liquid BIOREF-AFP control serum in their routine internal quality control over a period of one year. For statistical analysis the results were collected centrally. Results: The statistical analysis of the test results revealed considerable variation for the different laboratories. The deviations of the mean values of different laboratories from the overall mean value varied between 0.1 and 26.1%, and for most of the laboratories the deviation was round about 10%. The precision of measured values in the individual laboratories was in most cases acceptable: Nevertheless, the coefficients of variation of the individual laboratories ranged from 13 to 16.1%. Conclusions: In conclusion, this study indicates that AFP results vary between different laboratories albeit an international standard for AFP is available. Therefore, every laboratory should participate in external ring studies and should use a quality control serum independent of the test kit manufacturer for the internal quality control.


Egerer K.,Charité - Medical University of Berlin | Roggenbuck D.,GA Generic Assays GmbH | Roggenbuck D.,Lausitz University of Applied science | Buttner T.,GA Generic Assays GmbH | And 7 more authors.
Arthritis Research and Therapy | Year: 2011

Introduction: Diagnosis of antiphospholipid syndrome (APS) still remains a laboratory challenge due to the great diversity of antiphospholipid antibodies (aPL) and their significance regarding APS-diagnostic criteria.Methods: A multi-line dot assay (MLDA) employing phosphatidylserine (PS), phosphatidylinositol (PI), cardiolipin (CL), and beta2-glycoprotein I (β2 GPI) was used to detect aPL, immunoglobulin G (IgG) and immunoglobulin M (IgM) in 85 APS patients, 65 disease controls, and 79 blood donors. For comparison, anti-CL and anti-β2 GPI IgG and IgM were detected by enzyme-linked immunosorbent assay (ELISA).Results: The level of agreement of both methods was good for anti-CL IgG, moderate for anti-CL IgM, very good for anti-β2 GPI IgG, and moderate for anti-β2 GPI IgM (kappa = 0.641, 0.507, 0.803 and 0.506, respectively). The frequency of observed discrepancies for anti-CL IgG (1.75%), anti-CL IgM (3.93%), anti-β2 GPI IgG (1.75%), and anti-β2 GPI IgM (0.87%) was low (McNemar test, P < 0.05, not-significant, respectively). Sensitivity, specificity, positive (+LR) and negative (-LR) likelihood ratios for at least one positive aPL antibody assessed by ELISA were 58.8%, 95.8%, 14.1, and 0.4, respectively, and for at least three positive aPl IgM and/or one positive aPL IgG by MLDA were 67.1%, 96.5%, 19.3, and 0.3, respectively. The frequency of IgM to PI, PS and CL, and combination of three or more aPL IgM detected by MLDA was significantly higher in APS patients with cerebral transient ischemia (P < 0.05, respectively).Conclusions: The novel MLDA is a readily available, single-step, sensitive diagnostic tool for the multiplex detection of aPL antibodies in APS and a potential alternative for single aPL antibody testing by ELISA. © 2011 Egerer et al.; licensee BioMed Central Ltd.


Roggenbuck D.,LausitzUniversity of Applied science | Roggenbuck D.,GA GenericAssays GmbH | Egerer K.,Charité - Medical University of Berlin | von Landenberg P.,Institute For Labormedizin | And 4 more authors.
Autoimmunity Reviews | Year: 2012

Detection of anti-phospholipid (aPL) antibodies for state-of-the art diagnosis of antiphospholipid syndrome(APS) still remains a laboratory challenge due to the great diversity of aPL antibodies and their relevance with regard to the diagnostic criteria. According to the recently revised classification criteria for APS, several enzyme-linked immunosorbent assays (ELISAs) should be performed simultaneously in routine laboratories for the detection of aPL antibodies. Therefore, new approaches to aPL profiling have been proposed recently to provide information regarding diagnosis and eventually outcome in APS patients. Multiplex analysis could meet the increasing demand for cost-efficient detection and profiling of aPL antibodies. Multi-line immunodot assays or bead-based multiplex techniques candidate as alternatives to assess several aPL antibodies simultaneously employing different solid-phases for bound/free separation of reactants. Particularly, multi-line immunodot assays present an alternative to ELISA for aPL antibody detection and profiling in APS patients. The use of hydrophobic membranes as solid-surface by this technique appears to offer a distinct solid-phase reaction environment for the assessment of aPL antibodies. This article reviews novel developments in the field of laboratory diagnostics of APS with special emphasis on multiplex assays. © 2012.


Quadri A.,University of Zürich | Gojanovic B.,La Tour Sport Medicine SOMC. | Gojanovic B.,University of Lausanne | Noack P.,Swiss Olympic Medical Center Abtwil | And 4 more authors.
Schweizerische Zeitschrift fur Sportmedizin und Sporttraumatologie | Year: 2016

Introduction: Vitamin D deficiency is very prevalent in world population and growing evidence shows that also athletes are affected. Vitamin D deficiency causes beside bone disorders, musculoskeletal pain, muscle weakness and is associated with many other health disorders. For athletes in particular it may impair training and performance, prolong recovery and increase risk of injury. We therefore analyzed Vitamin D levels in Swiss athletes focusing on prevalence according to age, gender, seasonal variations, indoor or outdoor sports, sunscreen use and Vitamin D supplementation. Methods: This study was performed in a convenient sample of 655 Swiss Olympic athletes over one year. Blood samples were obtained and a questionnaire was filled in at Swiss Olympic Medical Centers or Bases during an annual routine exam. Data were then sent to the central laboratory of the Aarau hospital where they were processed and sent to us in an anonymized version. Vitamin D levels were categorized into deficiency (< 50 nmol/1), insufficiency (between 50 and 75 nmol/1) and adequate levels (> 75 nmol/1) of 25-hydroxyvi-tamin D. By means of the questionnaire, we assessed age, gender, type of sport, symptoms possibly related to Vitamin D deficiency during the last year, frequency of sunscreen use and Vitamin D-containing medications of the athletes. Results: 13.5% of the participants (total number = 651) presented a Vitamin D deficiency, 37.8% a Vitamin D insufficiency so that more than half of the athletes (51.2%) had inadequate Vitamin D levels. Inadequate Vitamin D levels were more prevalent in younger athletes, during seasons with lower sun exposure, in indoor sports during the sun deprived seasons, in athletes without vitamines supplementation and in athletes of lower Swiss Olympic classes compared to their counterparts. Conclusions: The results of the study show that the prevalence of inadequate Vitamin D levels in Swiss athletes is substantial for younger athletes (< 18 years of age) and for indoor athletes during sun deprived periods of the year. However, a general vitamin supplementation containing Vitamin D reduced the prevalence of Vitamin D inadequacy which is especially relevant during sun deprived seasons.


Orth M.,Institute For Laboratoriumsmedizin | Aufenanger J.,Klinikum Ingolstadt GmbH | Hoffmann G.,Trillium GmbH Medizinischer Fachverlag | Lichtinghagen R.,Institute For Klinische Chemie | And 2 more authors.
LaboratoriumsMedizin | Year: 2016

Commercial providers in wellness and lifestyle offer their customers numerous apps for the presentation of customers' health data. In Germany, the government patronizes the use of nation-wide electronic health records by the so-called "E-health legislation". This electronic health record should also contain laboratory reports. However, a prerequisite in laboratory medicine for this electronic record is the harmonization of pre-preanalytics (terminology, testing profiles, testing intervals), preanalytics (time of sampling, patient preparation, transport and storage of samples, analytics (sample quality, method, calibration, quality assurance) up to postanalytics (units, data format, reference intervals, decision values). Because of the high number of tests and the test specifications in laboratory medicine, this harmonization process is still ongoing despite numerous long-term national and international activities. Other challenges of electronic health records are related to data security (i.e. the integrity of laboratory reports) and to data privacy in particular with respect to the informational self-determination of the patients and the German Gene Diagnostics Act (GenDG). Recommendation: We recommend for reasons of patient safety to include only a few, selected laboratory tests which are commonly used to adjust the medication of the patient in the national electronic health record. © 2016 Walter de Gruyter GmbH, Berlin/Boston.


Kaiser P.,INSTAND e.V. Dusseldorf | Peetz D.,INSTAND e.V. Dusseldorf | Peetz D.,Institute For Labormedizin | Spannagl M.,INSTAND e.V. Dusseldorf | Spannagl M.,Ludwig Maximilians University of Munich
Diabetologe | Year: 2016

HbA1c is an important biomarker for diagnosis and therapeutic control of diabetes mellitus. The reliability of the analytical methods used in medical laboratories is thoroughly verified within the quality assurance of the internal and external quality control. The use of commutable, fresh whole blood as control material in ring trials for HbA1c will considerably improve therapeutic management and patient safety in the future. © 2016 Springer-Verlag Berlin Heidelberg


Ducamp S.,Center Francais des Porphyries | Ducamp S.,University Paris Diderot | Schneider-Yin X.,Institute For Labormedizin | De Rooij F.,Erasmus Medical Center | And 16 more authors.
Human Molecular Genetics | Year: 2013

Frameshift mutations in the last coding exon of the 5-aminolevulinate synthase (ALAS) 2 gene were described to activate the enzyme causing increased levels of zinc- and metal-free protoporphyrin in patients with X-linked dominant protoporphyria (XLDPP). Only two such so-called gain-of-function mutations have been reported since the description of XLDPP in 2008. In this study of four newly identified XLDPP families, we identified two novel ALAS2 gene mutations, a nonsense p.Q548X and a frameshift c.1651-1677del26bp, along with a known mutation (delAGTG) found in two unrelated families. Of relevance, a de novo somatic and germinal mosaicism was present in a delAGTG family. Such a phenomenon may explain the high proportion of this mutation in XLDPP worldwide. Enhancements of over 3- and 14-fold in the catalytic rate and specificity constant of purified recombinant XLDPP variants in relation to those of wild-type ALAS2 confirmed the gain of function ascribed to these enzymes. The fact that both p.Q548X and c.1651-1677del26bp are located in close proximity and upstream from the two previously described mutations led us to propose the presence of a large gain-of-function domain within the C-terminus of ALAS2. To test this hypothesis, we generated four additional nonsense mutants (p.A539X, p.G544X, p.G576X and p.V583X) surrounding the human XLDPP mutations and defined an ALAS2 gain-of-function domain with a minimal size of 33 amino acids. The identification of this gain-of-function domain provides important information on the enzymatic activity of ALAS2, which was proposed to be constitutively inhibited, either directly or indirectly, through its own C-terminus. © The Author 2012. Published by Oxford University Press. All rights reserved.


Steglich M.,Robert Koch Institute | Nitsche A.,Robert Koch Institute | Von Muller L.,Saarland University | Von Muller L.,Institute For Labormedizin | And 6 more authors.
PLoS ONE | Year: 2015

We applied whole-genome sequencing to reconstruct the spatial and temporal dynamics underpinning the expansion of Clostridium difficile ribotype 027 in Germany. Based on resequencing of genomes from 57 clinical C. difficile isolates, which had been collected from hospitalized patients at 36 locations throughout Germany between 1990 and 2012, we demonstrate that C. difficile genomes have accumulated sequence variation sufficiently fast to document the pathogen's spread at a regional scale. We detected both previously described lineages of fluoroquinolone-resistant C. difficile ribotype 027, FQR1 and FQR2. Using Bayesian phylogeographic analyses, we show that fluoroquinolone-resistant C. difficile 027 was imported into Germany at least four times, that it had been widely disseminated across multiple federal states even before the first outbreak was noted in 2007, and that it has continued to spread since. © 2015 Steglich et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Huber A.R.,Institute For Labormedizin
Therapeutische Umschau | Year: 2015

Outcome studies and health technology assessment and appraisals have become more and more prominent in regard to the utility of laboratory testing in clinical medicine. In the past years many valuable and useful studies have been published that demonstrate an increasing value of laboratory testing in a variety of clinical situations or for a good number of disease diagnosis and monitoring. An excellent outcome using laboratory testing can only be achieved when the tests (methods) have an outstanding performance in terms of sensitivity, specificity, imprecision and robustness. Further, not only has the test per se to be outstanding, it is also of uttermost importance that the clinical setting, in which the test is performed, fits and that the preanalytic requirements are fulfilled as well as that the statistical rules are followed. The laboratory test has to be incorporated into an integrated approach respecting in a weighted attempt as many as possible aspects of health care. © 2015 Verlag Hans Huber


Gruber R.,Institute For Labormedizin | Borgmann S.,Klinische Infektiologie und Hygiene
Zeitschrift fur Rheumatologie | Year: 2014

Laboratory diagnostics play a fundamental role in rheumatology but must always be interpreted in the context of symptoms and clinical signs. Laboratory tests have a variety of purposes, such as confirmation or negation of a diagnosis, differential diagnosis, evaluation of activity and prognosis, involvement of organs and drug side effects. Markers of inflammation and specific autoantibodies are the most important laboratory parameters in rheumatology. Thus, with the suspicion of rheumatoid arthritis the analysis of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), the rheumatoid factor and anti-cyclic citrullinated peptide (anti-CCP or ACPA) should be performed as the first line tests. Only a few antibody titers are suitable for monitoring of disease activity. Some autoantibodies exhibit such a high diagnostic value that the antibodies are included in the classification criteria or in the definition of a disease entity. © 2014 Springer-Verlag.

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