Pub Date : 2016-06-01DOI: 10.1515/labmed-2016-0010
Michael Torzewski, K. Lackner
Zusammenfassung: Die Liquorzytologie ist eine technisch vergleichsweise einfache, dabei aber diagnostisch aussagefähige, schnell durchzuführende und kostengünstige Untersuchung, die auch im Rahmen des Notfall- und Basisprogramms der Liquordiagnostik nicht fehlen sollte. Die korrekte Durchführung und Interpretation setzt allerdings einige Erfahrung voraus. Anhand ausgewählter Beispiele zu den Themen Blutung, Meningitis und Meningeosis wird die Wertigkeit der Zytologie demonstriert, die oftmals nicht nur eine Ergänzung zu den üblichen quantitativen Bestimmungen ist, sondern nicht selten auch erst den diagnostisch entscheidenden Hinweis auf die zugrundliegende Erkrankung liefert: Bei der Subarachnoidalblutung ist sie hinsichtlich der Sensitivität der kranialen Computertomographie oftmals überlegen. Bei einer parasitären Meningitis liefert sie aufgrund des Nachweises eosinophiler Granulozyten erst die wesentliche Differentialdiagnose. Auch hinter einer normalen Zellzahl verbirgt sich gelegentlich eine Meningeois neoplastica. Tumorzellen lassen sich dabei mit Hilfe der Immunzytologie näher zuordnen. Entscheidend für eine aussagekräftige Zytologie ist allerdings die strikte Einhaltung präanalytischer Anforderungen.
{"title":"Liquorzytologie: Eine aussagekräftige Methode zur Diagnostik von Erkrankungen des Zentralnervensystems","authors":"Michael Torzewski, K. Lackner","doi":"10.1515/labmed-2016-0010","DOIUrl":"https://doi.org/10.1515/labmed-2016-0010","url":null,"abstract":"Zusammenfassung: Die Liquorzytologie ist eine technisch vergleichsweise einfache, dabei aber diagnostisch aussagefähige, schnell durchzuführende und kostengünstige Untersuchung, die auch im Rahmen des Notfall- und Basisprogramms der Liquordiagnostik nicht fehlen sollte. Die korrekte Durchführung und Interpretation setzt allerdings einige Erfahrung voraus. Anhand ausgewählter Beispiele zu den Themen Blutung, Meningitis und Meningeosis wird die Wertigkeit der Zytologie demonstriert, die oftmals nicht nur eine Ergänzung zu den üblichen quantitativen Bestimmungen ist, sondern nicht selten auch erst den diagnostisch entscheidenden Hinweis auf die zugrundliegende Erkrankung liefert: Bei der Subarachnoidalblutung ist sie hinsichtlich der Sensitivität der kranialen Computertomographie oftmals überlegen. Bei einer parasitären Meningitis liefert sie aufgrund des Nachweises eosinophiler Granulozyten erst die wesentliche Differentialdiagnose. Auch hinter einer normalen Zellzahl verbirgt sich gelegentlich eine Meningeois neoplastica. Tumorzellen lassen sich dabei mit Hilfe der Immunzytologie näher zuordnen. Entscheidend für eine aussagekräftige Zytologie ist allerdings die strikte Einhaltung präanalytischer Anforderungen.","PeriodicalId":49926,"journal":{"name":"Laboratoriumsmedizin-Journal of Laboratory Medicine","volume":"14 1","pages":"191 - 198"},"PeriodicalIF":0.0,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82408554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-04-01DOI: 10.1515/labmed-2015-0112
R. Haeckel, W. Wosniok, E. Gurr, Burkhard Peil
Abstract: The DGKL Working Group Guide Limits (Arbeitsgruppe Richtwerte) has published a proposal for deriving permissible analytical uncertainty limits related to biological variation data. Reference intervals were used to estimate biological variation. Biological variation data as basis for permissible uncertainty limits are generally accepted. These concepts usually apply a fixed factor leading to unrealistic stringent limits for quantities with a relatively small biological variation and to very permissive limits for quantities with relatively large biological variation. The working group has suggested a non-linear relation between biological variation and permissible uncertainty limits. The new approach has been exemplified with 84 quantities listed in the RiliBÄK (official German guidelines). The algorithms published allowed to derive permissible limits for all quantitative measurands in laboratory medicine. After its publication, three supplements appear necessary: 1. additional specifications of standard uncertainty, 2. a discussion on permissible limits for diagnosis and monitoring purposes, and 3. a discussion on circular reasoning in our approach.
{"title":"Supplements to a recent proposal for permissible uncertainty of measurements in laboratory medicine","authors":"R. Haeckel, W. Wosniok, E. Gurr, Burkhard Peil","doi":"10.1515/labmed-2015-0112","DOIUrl":"https://doi.org/10.1515/labmed-2015-0112","url":null,"abstract":"Abstract: The DGKL Working Group Guide Limits (Arbeitsgruppe Richtwerte) has published a proposal for deriving permissible analytical uncertainty limits related to biological variation data. Reference intervals were used to estimate biological variation. Biological variation data as basis for permissible uncertainty limits are generally accepted. These concepts usually apply a fixed factor leading to unrealistic stringent limits for quantities with a relatively small biological variation and to very permissive limits for quantities with relatively large biological variation. The working group has suggested a non-linear relation between biological variation and permissible uncertainty limits. The new approach has been exemplified with 84 quantities listed in the RiliBÄK (official German guidelines). The algorithms published allowed to derive permissible limits for all quantitative measurands in laboratory medicine. After its publication, three supplements appear necessary: 1. additional specifications of standard uncertainty, 2. a discussion on permissible limits for diagnosis and monitoring purposes, and 3. a discussion on circular reasoning in our approach.","PeriodicalId":49926,"journal":{"name":"Laboratoriumsmedizin-Journal of Laboratory Medicine","volume":"209 1","pages":"141 - 145"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80600307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-04-01DOI: 10.1515/labmed-2015-0086
R. Kocabaş, A. K. Erenler, M. Yetim, T. Doğan, H. K. Erdemli
Abstract Background: Acute coronary syndrome defines a broad spectrum of complaints from angina to irreversible myocardial damage. There is an ongoing need for a biomarker to predict and diagnose acute myocardial infarction (AMI) in the early stage. In this study, our aim was to reveal early diagnostic value of butyrylcholinesterase (BChE) in discrimination of healthy subjects and patients with AMI. Methods: Eighty-five patients admitted to our hospital due to AMI and 45 healthy subjects were involved in the study. Patients and controls were compared according to BChE, lipid profiles and biochemical parameters. Results: The serum BChE activity was significantly lower in patients with AMI than in the controls (p<0.001). After correlation analysis, while a negative correlation was determined between the serum BChE concentrations and AMI presence (r=–0.363, p<0.001); a positive correlation was determined between the serum BChE and cholesterol (r=0.443, p<0.001), HDL (r=0.243, p=0.006) and LDL (r=0.369, p<0.001) levels. The data indicate that BChE is associated with AMI and a subsequent receiver operating characteristic curve (ROC) analysis revealed that BChE, as an independent indicator, may differentiate AMI patients from controls. A cut-off point set at ≤7.15 kIU/L, BChE showed a sensitivity of 51.2% and a specificity of 84.4% (AUC=0.719, p<0.001). Conclusions: Low BChE level was significantly associated with AMI when compared to healthy subjects. Even though it has low sensitivity, plasma levels of BChE might represent an additional marker in the diagnostic network of AMI.
{"title":"Butyrylcholinesterase as an additional marker in the diagnostic network of acute myocardial infarction","authors":"R. Kocabaş, A. K. Erenler, M. Yetim, T. Doğan, H. K. Erdemli","doi":"10.1515/labmed-2015-0086","DOIUrl":"https://doi.org/10.1515/labmed-2015-0086","url":null,"abstract":"Abstract Background: Acute coronary syndrome defines a broad spectrum of complaints from angina to irreversible myocardial damage. There is an ongoing need for a biomarker to predict and diagnose acute myocardial infarction (AMI) in the early stage. In this study, our aim was to reveal early diagnostic value of butyrylcholinesterase (BChE) in discrimination of healthy subjects and patients with AMI. Methods: Eighty-five patients admitted to our hospital due to AMI and 45 healthy subjects were involved in the study. Patients and controls were compared according to BChE, lipid profiles and biochemical parameters. Results: The serum BChE activity was significantly lower in patients with AMI than in the controls (p<0.001). After correlation analysis, while a negative correlation was determined between the serum BChE concentrations and AMI presence (r=–0.363, p<0.001); a positive correlation was determined between the serum BChE and cholesterol (r=0.443, p<0.001), HDL (r=0.243, p=0.006) and LDL (r=0.369, p<0.001) levels. The data indicate that BChE is associated with AMI and a subsequent receiver operating characteristic curve (ROC) analysis revealed that BChE, as an independent indicator, may differentiate AMI patients from controls. A cut-off point set at ≤7.15 kIU/L, BChE showed a sensitivity of 51.2% and a specificity of 84.4% (AUC=0.719, p<0.001). Conclusions: Low BChE level was significantly associated with AMI when compared to healthy subjects. Even though it has low sensitivity, plasma levels of BChE might represent an additional marker in the diagnostic network of AMI.","PeriodicalId":49926,"journal":{"name":"Laboratoriumsmedizin-Journal of Laboratory Medicine","volume":"16 1","pages":"147 - 152"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83047947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-04-01DOI: 10.1515/labmed-2016-0013
J. Kleine‐Tebbe, L. Poulsen, R. Hamilton
Abstract: Assays for total and allergen-specific (s) IgE are essential serological tests in the diagnostic work-up of immediate type hypersensitivity reactions and atopic diseases. Technical performance characteristics and clinical utility of IgE tests have been published in international guidelines. In the USA and in Europe, IgE tests are mainly performed by accredited medical laboratories and in Germany they are also performed by allergists carrying an OIII-limited license. Both have to perform continuously internal and external quality control measures including proficiency trials twice a year (in Germany). Due to the heterogeneity of the assay’s core allergen reagents, complex extracts and more recently defined allergenic molecules, and heterologous assay calibration, the results of qualitative and quantitative sIgE tests from different diagnostic manufacturers can vary considerably. Proficiency trial results are subsequently grouped according to each assay type. Passing acceptance criteria depend on national rules and regarding quality management. Future challenges include a more valid quantification of sIgE which would allow true comparisons with the international units for total IgE, and the use of harmonized allergen reagents for the most important allergen sources, which have hampered inter-assay comparability in the past.
{"title":"Quality management in IgE-based allergy diagnostics","authors":"J. Kleine‐Tebbe, L. Poulsen, R. Hamilton","doi":"10.1515/labmed-2016-0013","DOIUrl":"https://doi.org/10.1515/labmed-2016-0013","url":null,"abstract":"Abstract: Assays for total and allergen-specific (s) IgE are essential serological tests in the diagnostic work-up of immediate type hypersensitivity reactions and atopic diseases. Technical performance characteristics and clinical utility of IgE tests have been published in international guidelines. In the USA and in Europe, IgE tests are mainly performed by accredited medical laboratories and in Germany they are also performed by allergists carrying an OIII-limited license. Both have to perform continuously internal and external quality control measures including proficiency trials twice a year (in Germany). Due to the heterogeneity of the assay’s core allergen reagents, complex extracts and more recently defined allergenic molecules, and heterologous assay calibration, the results of qualitative and quantitative sIgE tests from different diagnostic manufacturers can vary considerably. Proficiency trial results are subsequently grouped according to each assay type. Passing acceptance criteria depend on national rules and regarding quality management. Future challenges include a more valid quantification of sIgE which would allow true comparisons with the international units for total IgE, and the use of harmonized allergen reagents for the most important allergen sources, which have hampered inter-assay comparability in the past.","PeriodicalId":49926,"journal":{"name":"Laboratoriumsmedizin-Journal of Laboratory Medicine","volume":"31 1","pages":"81 - 96"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84918150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-04-01DOI: 10.1515/labmed-2015-0020
A. Bauer, D. Rudzki, M. Auer, H. Hegen, F. Deisenhammer
Abstract Background: One of the first line treatments for relapsing-remitting multiple sclerosis (RRMS) is interferon-β (IFNb), a cytokine with immune-modulatory effects. There is a high degree of variability in the response to the drug which is, among other factors, due to the presence of neutralizing antibodies (NABs) occurring late during therapy. Methods: The objective of this study was to determine whether the response to IFNb therapy and NAB development can be predicted based on the expression levels of the type-I interferon receptors IFNAR1, IFNAR2a, IFNAR2b, and IFNAR2c before start of treatment. The IFNAR expression levels in 163 samples of patients with relapsing-remitting MS were measured by real-time polymerase chain reaction (PCR). Results: Pre-treatment IFNAR2c expression levels were somewhat lower in patients who developed NAB during treatment compared to NAB-negative patients. No significant differences in the expression levels of other IFNAR subtypes and isotypes were found. Baseline IFNAR levels were not predictive of the clinical response after 2 years. Conclusions: Overall, there was a small, non-significant effect of IFNAR2c baseline levels on NAB development but no relation to clinical endpoints. Lower expression of IFNAR2c receptors could lead to higher IFNb levels inducing a higher rate of antibody response.
{"title":"Expression of interferon type-I receptor isoforms, clinical response and development of neutralizing antibodies in multiple sclerosis patients – results of a prospective study","authors":"A. Bauer, D. Rudzki, M. Auer, H. Hegen, F. Deisenhammer","doi":"10.1515/labmed-2015-0020","DOIUrl":"https://doi.org/10.1515/labmed-2015-0020","url":null,"abstract":"Abstract Background: One of the first line treatments for relapsing-remitting multiple sclerosis (RRMS) is interferon-β (IFNb), a cytokine with immune-modulatory effects. There is a high degree of variability in the response to the drug which is, among other factors, due to the presence of neutralizing antibodies (NABs) occurring late during therapy. Methods: The objective of this study was to determine whether the response to IFNb therapy and NAB development can be predicted based on the expression levels of the type-I interferon receptors IFNAR1, IFNAR2a, IFNAR2b, and IFNAR2c before start of treatment. The IFNAR expression levels in 163 samples of patients with relapsing-remitting MS were measured by real-time polymerase chain reaction (PCR). Results: Pre-treatment IFNAR2c expression levels were somewhat lower in patients who developed NAB during treatment compared to NAB-negative patients. No significant differences in the expression levels of other IFNAR subtypes and isotypes were found. Baseline IFNAR levels were not predictive of the clinical response after 2 years. Conclusions: Overall, there was a small, non-significant effect of IFNAR2c baseline levels on NAB development but no relation to clinical endpoints. Lower expression of IFNAR2c receptors could lead to higher IFNb levels inducing a higher rate of antibody response.","PeriodicalId":49926,"journal":{"name":"Laboratoriumsmedizin-Journal of Laboratory Medicine","volume":"6 1","pages":"119 - 124"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80908791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-04-01DOI: 10.1515/labmed-2015-0083
Alexandra Dorn-Beineke, U. Sack
Zusammenfassung: Die Durchflusszytometrie hat sich in der Labordiagnostik als unverzichtbare Spezialmethode durchgesetzt. Wegen der Besonderheiten in der Analytik vitaler Zellen stellt die Einführung und Gewährleistung von Qualitätsmanagementsystemen eine Herausforderung dar. Zur Qualitätskontrolle und Validierung in der diagnostischen Durchflusszytometrie liegen mittlerweile Erfahrungen vor, die in diesem Beitrag zusammenfassend dargestellt werden. Im Fokus stehen dabei die relevanten Regelwerke für diagnostische Laboratorien und die damit verbundenen Anforderungen an die medizinische Diagnostik, neben den Richtlinien der Bundesärztekammer (RiliBÄK) insbesondere die Akkreditierung nach DIN EN ISO 15189. Dabei werden Faktoren mit Einfluss auf durchflusszytometrische Analysen, Strategien zur Standardisierung und Harmonisierung in der Durchflusszytometrie und Möglichkeiten zur Verifizierung und Validierung im durchflusszytometrischen Labor aufgezeigt. Eine Zusammenfassung häufiger Qualitätsprobleme schließt die Darstellung ab. Abstract: Diagnostic flow cytometry has been established in laboratory diagnostics as an indispensable, deeply specialized method. Because of the special needs of the analysis in vital cells, the introduction and maintenance of quality management systems stays a challenge. Meanwhile, experience has been collected for quality controls and validation in diagnostic flow cytometry. This will be summarized in this article. The focus will be on the relevant rules and regulations for diagnostic laboratories and the associated requirements for medical diagnostics, besides the guidelines of the Bundesärztekammer (RiliBÄK) in particular the accreditation according to DIN EN ISO 15189. In detail, factors with influence on flow cytometry analyses, strategies for the standardization and harmonization in flow cytometry, and possibilities for verification and validation in the flow cytometry laboratory are given. A summary of the most frequent quality problems rounds up this overview.
{"title":"Qualitätskontrolle und Validierung in der diagnostischen Durchflusszytometrie","authors":"Alexandra Dorn-Beineke, U. Sack","doi":"10.1515/labmed-2015-0083","DOIUrl":"https://doi.org/10.1515/labmed-2015-0083","url":null,"abstract":"Zusammenfassung: Die Durchflusszytometrie hat sich in der Labordiagnostik als unverzichtbare Spezialmethode durchgesetzt. Wegen der Besonderheiten in der Analytik vitaler Zellen stellt die Einführung und Gewährleistung von Qualitätsmanagementsystemen eine Herausforderung dar. Zur Qualitätskontrolle und Validierung in der diagnostischen Durchflusszytometrie liegen mittlerweile Erfahrungen vor, die in diesem Beitrag zusammenfassend dargestellt werden. Im Fokus stehen dabei die relevanten Regelwerke für diagnostische Laboratorien und die damit verbundenen Anforderungen an die medizinische Diagnostik, neben den Richtlinien der Bundesärztekammer (RiliBÄK) insbesondere die Akkreditierung nach DIN EN ISO 15189. Dabei werden Faktoren mit Einfluss auf durchflusszytometrische Analysen, Strategien zur Standardisierung und Harmonisierung in der Durchflusszytometrie und Möglichkeiten zur Verifizierung und Validierung im durchflusszytometrischen Labor aufgezeigt. Eine Zusammenfassung häufiger Qualitätsprobleme schließt die Darstellung ab. Abstract: Diagnostic flow cytometry has been established in laboratory diagnostics as an indispensable, deeply specialized method. Because of the special needs of the analysis in vital cells, the introduction and maintenance of quality management systems stays a challenge. Meanwhile, experience has been collected for quality controls and validation in diagnostic flow cytometry. This will be summarized in this article. The focus will be on the relevant rules and regulations for diagnostic laboratories and the associated requirements for medical diagnostics, besides the guidelines of the Bundesärztekammer (RiliBÄK) in particular the accreditation according to DIN EN ISO 15189. In detail, factors with influence on flow cytometry analyses, strategies for the standardization and harmonization in flow cytometry, and possibilities for verification and validation in the flow cytometry laboratory are given. A summary of the most frequent quality problems rounds up this overview.","PeriodicalId":49926,"journal":{"name":"Laboratoriumsmedizin-Journal of Laboratory Medicine","volume":"97 1","pages":"65 - 79"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85916809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-04-01DOI: 10.1515/labmed-2015-0075
N. Buchmann, K. Norman, I. Demuth, E. Steinhagen-Thiessen
Zusammenfassung Hintergrund: Als metabolisches Syndrom (MetS) wird ein Symptomkomplex metabolischer Veränderungen bezeichnet, der eng mit Insulinresistenz (IR) assoziiert ist. Cutoff Werte für HOMA-IR, einem Surrogatparameter für IR, zur Identifikation von Probanden mit MetS sind nicht etabliert. Methoden: Insgesamt lagen Querschnittsdaten von 446 Studienteilnehmern im jüngeren Lebensalter (53% Frauen, 28±3 Jahre alt) und 1271 im höheren Lebensalter (52% Frauen, 68±4 Jahre alt) ohne Diabetes vor. MetS wurde nach den IDF/AHA/NHLBI (International Diabetes Foundation/American Heart Association/National Health, Lung and Blood Institute) Kriterien von 2009 definiert. Mittels ROC-Analyse wurden Cutoff-Werte für HOMA-IR berechnet, oberhalb derer Probanden mit MetS mit höchster Sensitivität und Spezifität erkannt werden konnten. Zuletzt wurden binär logistische Regressionsmodelle berechnet. Ergebnisse: Die Prävalenz von MetS betrug 6,7% bei den jungen und 28,3% bei den älteren Probanden. Cutoff-Werte für HOMA-IR, oberhalb derer MetS identifiziert werden konnte, waren HOMA-IR >1,88 (bei jungen Studienteilnehmern; Sensitivität 80%, Spezifität 85,3%, positiv prädiktiver Wert 80%, negativ prädiktiver Wert 15%) und HOMA-IR >1,98 (bei den älteren Studienteilnehmern; Sensitivität 73,6%, Spezifität 72,9%, positiv prädiktiver Wert 74%, negativ prädiktiver Wert 27%). Patienten oberhalb dieser Cutoff-Werte hatten im höchst adjustierten (Alter, BMI, Geschlecht, körperliche Aktivität und getrennt nach Altersgruppen) binären Regressionsmodell Odds von 5,7 (95% CI: 4,1–7,9) bei älteren und 22,2 (95% CI: 7,0–70,5) bei jüngeren Studienteilnehmern, MetS aufzuweisen. Schlussfolgerungen: Cutoff-Werte für HOMA-IR sind im Klinikalltag nicht etabliert, könnten aber herangezogen werden, um Personen mit MetS zu identifizieren und gegebenenfalls frühzeitig eine Therapie einzuleiten, auch wenn aufgrund der negativen prädiktiven Werte eine Diagnostik des MetS durch HOMA-IR allein nicht erfolgen kann.
{"title":"Surrogatmarker der Insulinresistenz bei Studienteilnehmern mit metabolischem Syndrom – Daten der Berliner Altersstudie II","authors":"N. Buchmann, K. Norman, I. Demuth, E. Steinhagen-Thiessen","doi":"10.1515/labmed-2015-0075","DOIUrl":"https://doi.org/10.1515/labmed-2015-0075","url":null,"abstract":"Zusammenfassung Hintergrund: Als metabolisches Syndrom (MetS) wird ein Symptomkomplex metabolischer Veränderungen bezeichnet, der eng mit Insulinresistenz (IR) assoziiert ist. Cutoff Werte für HOMA-IR, einem Surrogatparameter für IR, zur Identifikation von Probanden mit MetS sind nicht etabliert. Methoden: Insgesamt lagen Querschnittsdaten von 446 Studienteilnehmern im jüngeren Lebensalter (53% Frauen, 28±3 Jahre alt) und 1271 im höheren Lebensalter (52% Frauen, 68±4 Jahre alt) ohne Diabetes vor. MetS wurde nach den IDF/AHA/NHLBI (International Diabetes Foundation/American Heart Association/National Health, Lung and Blood Institute) Kriterien von 2009 definiert. Mittels ROC-Analyse wurden Cutoff-Werte für HOMA-IR berechnet, oberhalb derer Probanden mit MetS mit höchster Sensitivität und Spezifität erkannt werden konnten. Zuletzt wurden binär logistische Regressionsmodelle berechnet. Ergebnisse: Die Prävalenz von MetS betrug 6,7% bei den jungen und 28,3% bei den älteren Probanden. Cutoff-Werte für HOMA-IR, oberhalb derer MetS identifiziert werden konnte, waren HOMA-IR >1,88 (bei jungen Studienteilnehmern; Sensitivität 80%, Spezifität 85,3%, positiv prädiktiver Wert 80%, negativ prädiktiver Wert 15%) und HOMA-IR >1,98 (bei den älteren Studienteilnehmern; Sensitivität 73,6%, Spezifität 72,9%, positiv prädiktiver Wert 74%, negativ prädiktiver Wert 27%). Patienten oberhalb dieser Cutoff-Werte hatten im höchst adjustierten (Alter, BMI, Geschlecht, körperliche Aktivität und getrennt nach Altersgruppen) binären Regressionsmodell Odds von 5,7 (95% CI: 4,1–7,9) bei älteren und 22,2 (95% CI: 7,0–70,5) bei jüngeren Studienteilnehmern, MetS aufzuweisen. Schlussfolgerungen: Cutoff-Werte für HOMA-IR sind im Klinikalltag nicht etabliert, könnten aber herangezogen werden, um Personen mit MetS zu identifizieren und gegebenenfalls frühzeitig eine Therapie einzuleiten, auch wenn aufgrund der negativen prädiktiven Werte eine Diagnostik des MetS durch HOMA-IR allein nicht erfolgen kann.","PeriodicalId":49926,"journal":{"name":"Laboratoriumsmedizin-Journal of Laboratory Medicine","volume":"15 1","pages":"111 - 118"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81160896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-04-01DOI: 10.1515/labmed-2015-0049
M. Diller, M. Fleck
Zusammenfassung: Bei systemischen Autoimmunerkrankungen wie der rheumatoiden Arthritis, den Kollagenosen und den Vaskulitiden hat sich seit mehreren Jahren der Nachweis von Autoantikörpern im klinischen Alltag etabliert. Bei Patienten mit rheumatoider Arthritis (RA) gelingt allerdings nur bei 80% der Patienten ein Nachweis des Rheumafaktors (RF) oder anti-citrullinierter Protein/Peptid-Antikörper (ACPA). Als neue Biomarker für die RA gelten anti-CarP-Autoantikörper, die diese Lücke möglicherweise schließen könnten. Bei Kollagenosen erleichtert der Nachweis von ANA (Autonukleäre Antikörper) die Diagnosefindung wesentlich. Zu den ANAs zählen u.a. Anticentromer-AK, anti-Topoisomerase-I-[anti-Scl-70]-AK und anti-RNA-Polymerase-III-AK, die bei Patienten mit systemischer Sklerose nachgewiesen werden können und in den neuen Klassifikationskriterien berücksichtigt werden. Bei der Diagnose eines Antiphospholipidsyndroms spielt der Nachweis des Lupusantikoagulans und der aCL- bzw. anti-β2GPI-Antikörper der Isotypen IgG, IgM und IgA eine entscheidende Rolle. Antineutrophile-zytoplasmatische Antikörper (ANCA) sind wichtiger Bestandteil der Diagnostik bei Vaskultiden kleiner Gefäße und der Nachweis wird zunächst mit einem Screening über Immunfluoreszenztests (IFT) und mit anschließenden Immunoassays zum Nachweis der spezifischen Antikörper gegen Proteinase-3 (PR3) und Myeloperoxidase (MPO) geführt. Durch neue Schnelltestverfahren für anti-GBM-AK, anti-PR3-AK und anti-MPO-AK kann eine frühzeitigere Diagnosestellung bei kritisch kranken Vaskulitispatienten ermöglicht werden. Auch bei der Polymyalgia rheumatica und bei Patienten mit Spondyloarthritiden wird die Identifikation von neuen Biomarkern beschrieben; deren Stellenwert muss allerdings noch in weiteren Studien evaluiert werden.
摘要:近几年来，人们在日常生活中证实了车载抗体的系统免疫疾病，如风湿性关节炎、胶原蛋白和血管炎。不过，只有80%的患严重关节炎的患者身上才有类似的病菌。被列为防腐汽车抗体的新型生物标记在反胶原蛋白中，ANA(被认为有粘性抗体)的证明有助于诊断。有的被归正者有"抗衰老者ak "、反topo somerse i "、"抗rna聚合物"，这些在系统发性疾病病人中可被证明存在并在新的等级标准中得到承认。Antiphospholipidsyndroms扮演的诊断证明Lupusantikoagulans和aCL,或反β的2GPI-Antikörper Isotypen IgG、IgM和伊贺.起到关键作用抗重症细胞抗体(ANCA)是小型血管诊断技术的重要组成部分，而首次得到确认的手段是先通过免疫荧光测试(IFT)和随后的免疫绿卡确认针对蛋白质3 (PR3)和髓色素(MPO)的特殊抗体。有了新的快速检测方法来检测抗转基因病毒、抗pr3和抗mpo，针对罹患绝症的病人可以更早地诊断。聚菌素引起的新品种生物标记也表明了新生物标记的身份。但这些估算结果有待日后研究来评估。
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Pub Date : 2016-03-19DOI: 10.1515/labmed-2015-0116
M. Bidlingmaier, B. Hauffa, P. Trainer, G. Etzrodt-Walter, J. Sauer, J. Kratzsch, S. Petersenn, M. Ranke, H. Wallaschofski, C. Strasburger
Abstract Background: Reliable laboratory analysis is fundamental to diagnostics, therapy, and follow-up of growth disturbance and secretory dysfunction of growth hormone (GH) and insulin-like growth factor I (IGF-I). Currently available commercial assays have their limitations, as they show large variations in hormone concentrations measured. Methods: The recommendations of an expert workshop with practicing endocrinologists from the fields of pediatrics and internal medicine and with laboratory physicians, with reference to the outcome of the interdisciplinary consensus conference in Keswick (Virginia, USA) in 2009, were used. Results: Among the quality criteria stipulated by the workshop participants are the use of uniform reference standards, documentation of analytical conditions (such as calibrators, binding epitopes, cross-reactivity, and methods for removal from the binding protein), batch-to-batch consistency, and low inter-assay variability. The participants recommended developing assay-specific thresholds and reference intervals based on large and well-defined reference populations. It is furthermore recommended to delineate the assay quality, particularly with reference to clinically important cutoffs. Conclusions: The manufacturers of diagnostic assays should be obliged to regularly monitor and report the implementation of quality criteria. Only assays that are evaluated according to uniform quality standards and that are employed clinically permit informed diagnostic and therapy of patients with GH secretory dysfunction, preventing avoidable burden on both patients and paying authorities.
{"title":"Quality assurance in the analysis of growth hormone and insulin-like growth factor I in disorders of the somatotropic axis","authors":"M. Bidlingmaier, B. Hauffa, P. Trainer, G. Etzrodt-Walter, J. Sauer, J. Kratzsch, S. Petersenn, M. Ranke, H. Wallaschofski, C. Strasburger","doi":"10.1515/labmed-2015-0116","DOIUrl":"https://doi.org/10.1515/labmed-2015-0116","url":null,"abstract":"Abstract Background: Reliable laboratory analysis is fundamental to diagnostics, therapy, and follow-up of growth disturbance and secretory dysfunction of growth hormone (GH) and insulin-like growth factor I (IGF-I). Currently available commercial assays have their limitations, as they show large variations in hormone concentrations measured. Methods: The recommendations of an expert workshop with practicing endocrinologists from the fields of pediatrics and internal medicine and with laboratory physicians, with reference to the outcome of the interdisciplinary consensus conference in Keswick (Virginia, USA) in 2009, were used. Results: Among the quality criteria stipulated by the workshop participants are the use of uniform reference standards, documentation of analytical conditions (such as calibrators, binding epitopes, cross-reactivity, and methods for removal from the binding protein), batch-to-batch consistency, and low inter-assay variability. The participants recommended developing assay-specific thresholds and reference intervals based on large and well-defined reference populations. It is furthermore recommended to delineate the assay quality, particularly with reference to clinically important cutoffs. Conclusions: The manufacturers of diagnostic assays should be obliged to regularly monitor and report the implementation of quality criteria. Only assays that are evaluated according to uniform quality standards and that are employed clinically permit informed diagnostic and therapy of patients with GH secretory dysfunction, preventing avoidable burden on both patients and paying authorities.","PeriodicalId":49926,"journal":{"name":"Laboratoriumsmedizin-Journal of Laboratory Medicine","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81909132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-09DOI: 10.1515/labmed-2016-0016
A. Dorn‐Beineke, U. Sack
Abstract Diagnostic flow cytometry has been established in laboratory diagnostics as an indispensable, deeply specialized method. Because of the special needs of the analysis in vital cells, the introduction and maintenance of quality management systems stays a challenge. Meanwhile, experience has been collected for quality controls and validation in diagnostic flow cytometry. This will be summarized in this article. The focus will be on the relevant rules and regulations for diagnostic laboratories and the associated requirements for medical diagnostics, as well the guidelines of the German Medical Association, Bundesärztekammer, (RiliBÄK) and in particular the accreditation according to DIN EN ISO 15189. In detail, factors influencing flow cytometry analyses, strategies for the standardization and harmonization in flow cytometry, and possibilities for verification and validation in the flow cytometry laboratory are given. A summary of the most frequent quality problems rounds up this overview.
流式细胞术在实验室诊断中已成为一种不可缺少的、深度专业化的诊断方法。由于重要细胞分析的特殊需求，质量管理体系的引入和维护仍然是一个挑战。同时为流式细胞术诊断的质量控制和验证积累了经验。这将在本文中进行总结。重点将放在诊断实验室的相关规则和条例以及医疗诊断的相关要求，以及德国医学协会的指导方针Bundesärztekammer， (RiliBÄK)，特别是根据DIN EN ISO 15189的认证。详细介绍了影响流式细胞术分析的因素，流式细胞术标准化和协调的策略，以及流式细胞术实验室验证和验证的可能性。本文总结了最常见的质量问题。
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