Abstract Objectives We compare measurement uncertainty (MU) calculations to real patient result variation observed by physicians using as our model anion gap (AGAP) sequentially measured on two different instrument types. An approach for discretely quantifying the pre-analytical contributions and validating AGAP MU estimates for interpretation of patient results is proposed. Methods AGAP was calculated from sodium, chloride, and bicarbonate reported from chemistry or blood gas analyzers which employ different methodologies and specimen types. AGAP MU was calculated using a top-down approach both assuming no correlation between measurands and alternatively, including consideration of measurand correlation. MU-derived reference change values (RCV) were calculated between chemistry and blood gas analyzers results. Observational paired AGAP data (n=39,626 subjects) was obtained from retrospectively analyzed specimens from five urban tertiary care hospitals in Calgary, Alberta, Canada. Results The MU derived AGAP RCV for paired specimen data by the two platforms was 5.2–6.1 mmol/L assuming no correlation and 2.6–3.1 mmol/L assuming correlation. From the paired chemistry and blood gas data, total observed variation on a reported AGAP has a 95% confidence interval of ±6.0 mmol/L. When the MU-derived RCV assuming correlation is directly compared against the observed distribution of patient results, we obtained a pre-analytical variation contribution of 2.9–3.5 mmol/L to the AGAP observed variation. In contrast, assuming no correlation leads to a negligible pre-analytical contribution (<1.0 mmol/L). Conclusions MU estimates assuming no correlation are more representative of the total variation seen in real patient data. We present a pragmatic approach for validating an MU calculation to inform clinical decisions and determine the pre-analytical contribution to MU in this system.
{"title":"Filling in the GAPS: validation of anion gap (AGAP) measurement uncertainty estimates for use in clinical decision making","authors":"J. Gifford, I. Seiden-Long","doi":"10.1515/cclm-2021-1279","DOIUrl":"https://doi.org/10.1515/cclm-2021-1279","url":null,"abstract":"Abstract Objectives We compare measurement uncertainty (MU) calculations to real patient result variation observed by physicians using as our model anion gap (AGAP) sequentially measured on two different instrument types. An approach for discretely quantifying the pre-analytical contributions and validating AGAP MU estimates for interpretation of patient results is proposed. Methods AGAP was calculated from sodium, chloride, and bicarbonate reported from chemistry or blood gas analyzers which employ different methodologies and specimen types. AGAP MU was calculated using a top-down approach both assuming no correlation between measurands and alternatively, including consideration of measurand correlation. MU-derived reference change values (RCV) were calculated between chemistry and blood gas analyzers results. Observational paired AGAP data (n=39,626 subjects) was obtained from retrospectively analyzed specimens from five urban tertiary care hospitals in Calgary, Alberta, Canada. Results The MU derived AGAP RCV for paired specimen data by the two platforms was 5.2–6.1 mmol/L assuming no correlation and 2.6–3.1 mmol/L assuming correlation. From the paired chemistry and blood gas data, total observed variation on a reported AGAP has a 95% confidence interval of ±6.0 mmol/L. When the MU-derived RCV assuming correlation is directly compared against the observed distribution of patient results, we obtained a pre-analytical variation contribution of 2.9–3.5 mmol/L to the AGAP observed variation. In contrast, assuming no correlation leads to a negligible pre-analytical contribution (<1.0 mmol/L). Conclusions MU estimates assuming no correlation are more representative of the total variation seen in real patient data. We present a pragmatic approach for validating an MU calculation to inform clinical decisions and determine the pre-analytical contribution to MU in this system.","PeriodicalId":10388,"journal":{"name":"Clinical Chemistry and Laboratory Medicine (CCLM)","volume":"53 1","pages":"851 - 858"},"PeriodicalIF":0.0,"publicationDate":"2022-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87859519","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}
Y.B.L. Hansen, Koh Furuta, S. Devaraj, F. Yilmaz, G. Nordin
The mission of the Committee of Nomenclature for Properties and Units (C-NPU), a joint commission of International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and International Union of Pure Applied Chemists (IUPAC), is to recommend an standardized laboratory terminology for reporting laboratory results that include proper kinds-of-properties (e.g. category, mass concentration) and measurement units. In this letter, we express our deep concerns of a new unit concept recently introduced by WHO. The necessary, and prompt work byWHO to establish an international standard (IS) labelled 20/136, as a Certified Reference Material (CRM) for measurement of the activity of SARS CoV-2 antibodies, is acknowledged. However, in the correspondence “WHO International Standard for anti-SARS CoV-2 immunoglobulin,”wewere puzzled by the newmetrological unit concept, referred as “Binding Antibody Unit” (BAU) [1]. In version 1.0 of the certificate for IS 20/136, the value “250 IU/ampoule” was assigned for both calibration of measurements of neutralizing antibodies and for (“binding”) antibodies [2]. In the second version, BAU was introduced as a unit concept for harmonization (n.b. not calibration) of results from binding antibody assays [3]. The reason was recently developed: “For example, it is inappropriate to assign a protective titre for vaccine efficacy in IU/mL when using an assay that is not measuring an antigen associated with protection. Such cases have arisen formeasles and rubella, and have led to amisplaced lack of confidence in the use of the International Standard” [4]. Hence, the reason to introduce separate units for results from “neutralising antibody” assays and results from “binding antibody” assays, was the lack of confidence to CRM when users had not clearly distinguished two different measurands. The use of separate unit names for the same kind-of-quantity (e.g. mass concentration), instead of separate names for the components (analytes), is a deviation from international nomenclature conventions used byWHO to assign International Units to CRM [5]. It is a concern that should cause alarms in scientific societies, standardisation bodies and health care organisations. Before the SI unit system, literally numerous different units for the same kind-of-quantity existed [6, 7]. This nontransparent practice created confusion in trade (exchanging goods with measurements) across geographically borders, even between close-by-cities. Same confusion can and will happen in health care with potentially mistreatment of patients if multiple international units are introduced for results of the same kind-of-quantity. Thus, a limited number of internationally recognized units (preferable SI units or international recognized nonSI units) has been recommended in laboratory medicine since 1966 [8]. However, it is acknowledged that it may not be possible to assign an SI unit to a measurand of a CRM, e.g. CRM for a biological activity. In these cas
性质和单位命名委员会(C-NPU)是国际临床化学和检验医学联合会(IFCC)和国际纯粹应用化学家联合会(IUPAC)的联合委员会，其任务是为报告实验室结果推荐一种标准化的实验室术语，其中包括适当种类的性质(例如类别、质量浓度)和测量单位。在这封信中，我们对世卫组织最近提出的一个新的单位概念深表关切。世卫组织为建立标记为20/136的国际标准(IS)，作为测量SARS CoV-2抗体活性的认证参考物质(CRM)所做的必要和迅速的工作得到了认可。然而，在《WHO抗sars CoV-2免疫球蛋白国际标准》的通信中，我们对新的计量单位概念“结合抗体单位”(Binding Antibody unit, BAU)感到困惑[1]。在IS 20/136证书的1.0版本中，“250 IU/安瓿”的值被指定用于校准中和抗体和(“结合”)抗体的测量[2]。在第二个版本中，引入了BAU作为统一(不是校准)结合抗体测定结果的单位概念[3]。原因是最近提出的:“例如，当使用一种不测量与保护相关的抗原的测定方法时，以IU/mL为单位指定疫苗效力的保护滴度是不合适的。麻疹和风疹也出现了这样的病例，并导致对使用国际标准缺乏信心”[4]。因此，引入“中和抗体”测定结果和“结合抗体”测定结果的单独单位的原因是，当用户没有明确区分两种不同的测量方法时，对CRM缺乏信心。对同一种类的数量(如质量浓度)使用单独的单位名称，而不是对组分(分析物)使用单独的名称，这偏离了世卫组织为CRM指定国际单位的国际命名惯例[5]。这是一个应该引起科学协会、标准化机构和卫生保健组织警觉的问题。在SI单位制之前，同一种类的量实际上有许多不同的单位[6,7]。这种不透明的做法在跨越地理边界的贸易(用度量交换货物)中造成了混乱，甚至在邻近的城市之间也是如此。如果采用多个国际单位以获得相同数量的结果，那么在医疗保健中可能而且将会发生同样的混淆，可能会对患者造成不当对待。因此，自1966年以来，实验室医学中推荐了有限数量的国际认可单位(优选SI单位或国际认可的非SI单位)[8]。然而，公认的是，可能不可能将SI单位分配给CRM的测量，例如用于生物活性的CRM。在这些情况下，世卫组织对CRM中某一生物物质的含量任意赋值，以国际单位(IU)的倍数表示。例如，肝炎病毒crm的所有作者都是C-NPU的成员。
{"title":"Misleading nomenclature of units of WHO materials used for standardization of SARS COv-2 serology","authors":"Y.B.L. Hansen, Koh Furuta, S. Devaraj, F. Yilmaz, G. Nordin","doi":"10.1515/cclm-2022-0082","DOIUrl":"https://doi.org/10.1515/cclm-2022-0082","url":null,"abstract":"The mission of the Committee of Nomenclature for Properties and Units (C-NPU), a joint commission of International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and International Union of Pure Applied Chemists (IUPAC), is to recommend an standardized laboratory terminology for reporting laboratory results that include proper kinds-of-properties (e.g. category, mass concentration) and measurement units. In this letter, we express our deep concerns of a new unit concept recently introduced by WHO. The necessary, and prompt work byWHO to establish an international standard (IS) labelled 20/136, as a Certified Reference Material (CRM) for measurement of the activity of SARS CoV-2 antibodies, is acknowledged. However, in the correspondence “WHO International Standard for anti-SARS CoV-2 immunoglobulin,”wewere puzzled by the newmetrological unit concept, referred as “Binding Antibody Unit” (BAU) [1]. In version 1.0 of the certificate for IS 20/136, the value “250 IU/ampoule” was assigned for both calibration of measurements of neutralizing antibodies and for (“binding”) antibodies [2]. In the second version, BAU was introduced as a unit concept for harmonization (n.b. not calibration) of results from binding antibody assays [3]. The reason was recently developed: “For example, it is inappropriate to assign a protective titre for vaccine efficacy in IU/mL when using an assay that is not measuring an antigen associated with protection. Such cases have arisen formeasles and rubella, and have led to amisplaced lack of confidence in the use of the International Standard” [4]. Hence, the reason to introduce separate units for results from “neutralising antibody” assays and results from “binding antibody” assays, was the lack of confidence to CRM when users had not clearly distinguished two different measurands. The use of separate unit names for the same kind-of-quantity (e.g. mass concentration), instead of separate names for the components (analytes), is a deviation from international nomenclature conventions used byWHO to assign International Units to CRM [5]. It is a concern that should cause alarms in scientific societies, standardisation bodies and health care organisations. Before the SI unit system, literally numerous different units for the same kind-of-quantity existed [6, 7]. This nontransparent practice created confusion in trade (exchanging goods with measurements) across geographically borders, even between close-by-cities. Same confusion can and will happen in health care with potentially mistreatment of patients if multiple international units are introduced for results of the same kind-of-quantity. Thus, a limited number of internationally recognized units (preferable SI units or international recognized nonSI units) has been recommended in laboratory medicine since 1966 [8]. However, it is acknowledged that it may not be possible to assign an SI unit to a measurand of a CRM, e.g. CRM for a biological activity. In these cas","PeriodicalId":10388,"journal":{"name":"Clinical Chemistry and Laboratory Medicine (CCLM)","volume":"325 1","pages":"e151 - e152"},"PeriodicalIF":0.0,"publicationDate":"2022-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80348110","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}
A. Meinitzer, D. Enko, S. Zelzer, F. Prüller, N. Alonso, E. Fritz-Petrin, M. Herrmann
Abstract Objectives Vitamin K and metabolites have a beneficial role in blood coagulation, bone metabolism and growth. However, the determination of vitamin K concentrations in the blood in patients consuming a diet with naturally occurring vitamin K is currently challenging. We aim to develop a cost-effective and rapid method to measure vitamin K metabolites with potential application for clinics and research. Methods We developed a simple liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of vitamin K1, menaquinone-4 (MK-4), menaquinone-7 (MK-7) and vitamin K1-2,3 epoxide in human serum and validated the method in a study cohort of 162 patients tested for carbohydrate malabsorption and in 20 patients with oral phenprocoumon intake. Results The overall precision (CVs) ranged between 4.8 and 17.7% in the specified working range (0.06–9.0 nmol/L for all analytes except for MK-7 with 0.04–6.16 nmol/L). In the malabsorption cohort samples, measured values were obtained for all different vitamin K metabolites except for vitamin K1-2,3 epoxide. This metabolite could be detected only in patients with phenprocoumon intake. The good performance of the method is especially achieved by the interaction of three factors: the use of lipase in the sample preparation, the use of an atypical fluorinated reversed phase column, and a logarithmic methanol gradient. Conclusions The described method is able to determine the concentration of four vitamin K metabolites in a time-efficient, simple and cost-effective manner. It can be suitable for both routine clinics and research.
{"title":"Development of a liquid chromatography mass spectrometry method for the determination of vitamin K1, menaquinone-4, menaquinone-7 and vitamin K1-2,3 epoxide in serum of individuals without vitamin K supplements","authors":"A. Meinitzer, D. Enko, S. Zelzer, F. Prüller, N. Alonso, E. Fritz-Petrin, M. Herrmann","doi":"10.1515/cclm-2022-0192","DOIUrl":"https://doi.org/10.1515/cclm-2022-0192","url":null,"abstract":"Abstract Objectives Vitamin K and metabolites have a beneficial role in blood coagulation, bone metabolism and growth. However, the determination of vitamin K concentrations in the blood in patients consuming a diet with naturally occurring vitamin K is currently challenging. We aim to develop a cost-effective and rapid method to measure vitamin K metabolites with potential application for clinics and research. Methods We developed a simple liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of vitamin K1, menaquinone-4 (MK-4), menaquinone-7 (MK-7) and vitamin K1-2,3 epoxide in human serum and validated the method in a study cohort of 162 patients tested for carbohydrate malabsorption and in 20 patients with oral phenprocoumon intake. Results The overall precision (CVs) ranged between 4.8 and 17.7% in the specified working range (0.06–9.0 nmol/L for all analytes except for MK-7 with 0.04–6.16 nmol/L). In the malabsorption cohort samples, measured values were obtained for all different vitamin K metabolites except for vitamin K1-2,3 epoxide. This metabolite could be detected only in patients with phenprocoumon intake. The good performance of the method is especially achieved by the interaction of three factors: the use of lipase in the sample preparation, the use of an atypical fluorinated reversed phase column, and a logarithmic methanol gradient. Conclusions The described method is able to determine the concentration of four vitamin K metabolites in a time-efficient, simple and cost-effective manner. It can be suitable for both routine clinics and research.","PeriodicalId":10388,"journal":{"name":"Clinical Chemistry and Laboratory Medicine (CCLM)","volume":"41 1","pages":"1011 - 1019"},"PeriodicalIF":0.0,"publicationDate":"2022-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90596432","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}
Marcus Clarin, Annika Petersson, H. Zetterberg, K. Ekblom
Abstract Objectives Spectrophotometric absorption curve analysis of cerebrospinal fluid (CSF) for oxyhaemoglobin and bilirubin is necessary to accurately diagnose subarachnoid haemorrhage (SAH) in patients with typical symptoms but with negative findings on X-ray examinations. In this study, we evaluated the performance of two methods for interpreting absorption curves; one method from the United Kingdom National External Quality Assessment Service (UK-NEQAS) and the other from the national quality assurance programme in Sweden (Equalis). Methods Consecutive absorbance curves (n=336) were interpreted with two different methods, and their performance was compared to the diagnosis as stated in the patient records. Results The UK-NEQAS method displayed equal sensitivity to the Equalis method, but the specificity of the UK-NEQAS method was significantly higher than the Equalis method resulting in fewer false positive results. For UK-NEQAS, a positive predictive value (PPV) of 84.6% and a negative predictive value (NPV) of 99.7% were observed, whereas the Equalis method had a PPV of 27.5% and an NPV of 99.7%. Conclusions The semi-automated method based on the guidelines from UK-NEQAS provides an efficient and correct interpretation of absorbance curves with short turn-around times. We propose using this method for the routine interpretation of CSF spectrophotometric curves.
{"title":"Detection of subarachnoid haemorrhage with spectrophotometry of cerebrospinal fluid – a comparison of two methods","authors":"Marcus Clarin, Annika Petersson, H. Zetterberg, K. Ekblom","doi":"10.1515/cclm-2021-1320","DOIUrl":"https://doi.org/10.1515/cclm-2021-1320","url":null,"abstract":"Abstract Objectives Spectrophotometric absorption curve analysis of cerebrospinal fluid (CSF) for oxyhaemoglobin and bilirubin is necessary to accurately diagnose subarachnoid haemorrhage (SAH) in patients with typical symptoms but with negative findings on X-ray examinations. In this study, we evaluated the performance of two methods for interpreting absorption curves; one method from the United Kingdom National External Quality Assessment Service (UK-NEQAS) and the other from the national quality assurance programme in Sweden (Equalis). Methods Consecutive absorbance curves (n=336) were interpreted with two different methods, and their performance was compared to the diagnosis as stated in the patient records. Results The UK-NEQAS method displayed equal sensitivity to the Equalis method, but the specificity of the UK-NEQAS method was significantly higher than the Equalis method resulting in fewer false positive results. For UK-NEQAS, a positive predictive value (PPV) of 84.6% and a negative predictive value (NPV) of 99.7% were observed, whereas the Equalis method had a PPV of 27.5% and an NPV of 99.7%. Conclusions The semi-automated method based on the guidelines from UK-NEQAS provides an efficient and correct interpretation of absorbance curves with short turn-around times. We propose using this method for the routine interpretation of CSF spectrophotometric curves.","PeriodicalId":10388,"journal":{"name":"Clinical Chemistry and Laboratory Medicine (CCLM)","volume":"27 1","pages":"1053 - 1057"},"PeriodicalIF":0.0,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75355939","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}
Abstract Objectives Estimated glomerular filtration rate (eGFR) can be calculated using serum/plasma creatinine measured with automated chemistry analyzers. It is unclear whether eGFR can be calculated using creatinine values measured in whole blood (WB creatinine). The aim of this study is to determine the comparability between the eGFR calculated using WB creatinine and plasma creatinine. Methods Blood samples from 1,073 patients presented to the emergency department (ED), perioperative areas, intensive care unit (ICU) or nuclear medicine were used to determine the accuracy of WB creatinine. For each sample, WB creatinine was first measured with Radiometer ABL827 FLEX blood gas analyzer, then plasma creatinine was measured with Roche Cobas702 chemistry analyzer after samples were centrifuged. In a subset of 247 samples with the information of age and sex, whole blood eGFR (WB eGFR) and plasma eGFR were calculated using WB creatinine and plasma creatinine and the 2021 chronic kidney disease epidemiology collaboration (CKD-EPI) creatinine equation, respectively. Results WB creatinine correlated with plasma creatinine linearly with a slope of 1.06 and an intercept of −0.01. The coefficient of determination (R2) was 0.99. WB eGFR correlated with plasma eGFR linearly with a slope of 0.95, intercept of −1.63, and R2 of 0.97. Comparing to plasma eGFR, the sensitivity and specificity for WB eGFR to identify those with high risk (eGFR<30 mL/min/1.73 m2) and low risk (eGFR>45 mL/min/1.73 m2) for kidney injuries was 100 and 92.2%, respectively. The overall concordance in classifying the four stages of kidney damage between WB eGFR and plasma eGFR was 87.9%. Conclusions WB creatinine measured with Radiometer ABL827 Flex can be used to calculate eGFR using the 2021 CKD-EPI creatinine equation. The sensitivity and specificity for WB eGFR to identify those with high and low risks for potential kidney injuries are acceptable in patients needing rapid assessment of their kidney functions.
{"title":"Calculation of the estimated glomerular filtration rate using the 2021 CKD-EPI creatinine equation and whole blood creatinine values measured with Radiometer ABL 827 FLEX","authors":"Lu Song, V. Buggs, V. Samara, S. Bahri","doi":"10.1515/cclm-2022-0059","DOIUrl":"https://doi.org/10.1515/cclm-2022-0059","url":null,"abstract":"Abstract Objectives Estimated glomerular filtration rate (eGFR) can be calculated using serum/plasma creatinine measured with automated chemistry analyzers. It is unclear whether eGFR can be calculated using creatinine values measured in whole blood (WB creatinine). The aim of this study is to determine the comparability between the eGFR calculated using WB creatinine and plasma creatinine. Methods Blood samples from 1,073 patients presented to the emergency department (ED), perioperative areas, intensive care unit (ICU) or nuclear medicine were used to determine the accuracy of WB creatinine. For each sample, WB creatinine was first measured with Radiometer ABL827 FLEX blood gas analyzer, then plasma creatinine was measured with Roche Cobas702 chemistry analyzer after samples were centrifuged. In a subset of 247 samples with the information of age and sex, whole blood eGFR (WB eGFR) and plasma eGFR were calculated using WB creatinine and plasma creatinine and the 2021 chronic kidney disease epidemiology collaboration (CKD-EPI) creatinine equation, respectively. Results WB creatinine correlated with plasma creatinine linearly with a slope of 1.06 and an intercept of −0.01. The coefficient of determination (R2) was 0.99. WB eGFR correlated with plasma eGFR linearly with a slope of 0.95, intercept of −1.63, and R2 of 0.97. Comparing to plasma eGFR, the sensitivity and specificity for WB eGFR to identify those with high risk (eGFR<30 mL/min/1.73 m2) and low risk (eGFR>45 mL/min/1.73 m2) for kidney injuries was 100 and 92.2%, respectively. The overall concordance in classifying the four stages of kidney damage between WB eGFR and plasma eGFR was 87.9%. Conclusions WB creatinine measured with Radiometer ABL827 Flex can be used to calculate eGFR using the 2021 CKD-EPI creatinine equation. The sensitivity and specificity for WB eGFR to identify those with high and low risks for potential kidney injuries are acceptable in patients needing rapid assessment of their kidney functions.","PeriodicalId":10388,"journal":{"name":"Clinical Chemistry and Laboratory Medicine (CCLM)","volume":"90 1","pages":"867 - 876"},"PeriodicalIF":0.0,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75295946","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}
{"title":"Effects of different pepsinogen cut offs in the screening of apparently healthy people","authors":"Shui Fu, Qiyan Hu, Liang Zhang, Zuo-Jie Li","doi":"10.1515/cclm-2022-0080","DOIUrl":"https://doi.org/10.1515/cclm-2022-0080","url":null,"abstract":"","PeriodicalId":10388,"journal":{"name":"Clinical Chemistry and Laboratory Medicine (CCLM)","volume":"23 1","pages":"e161 - e164"},"PeriodicalIF":0.0,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73713423","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}
Rosa Ferrer, N. Zhu, J. Arranz, I. Porcel, Shaimaa El Bounasri, Oriol Sánchez, Soraya Torres, J. Julve, A. Lleó, F. Blanco-Vaca, D. Alcolea, M. Tondo
Abstract Objectives Alzheimer’s disease (AD) is considered the most common cause of dementia in older people. Cerebrospinal fluid (CSF) Aβ1-42, Aβ1-40, total Tau (t-Tau), and phospho Tau (p-Tau) are important biomarkers for the diagnosis, however, they are highly dependent on the pre-analytical conditions. Our aim was to investigate the potential influence of different storage conditions on the simultaneous quantification of these biomarkers in a fully-automated platform to accommodate easier pre-analytical conditions for laboratories. Methods CSF samples were obtained from 11 consecutive patients. Aβ1-42, Aβ1-40, p-Tau, and t-Tau were quantified using the LUMIPULSE G600II automated platform. Results Temperature and storage days significantly influenced Aβ1-42 and Aβ1-40 with concentrations decreasing with days spent at 4 °C. The use of the Aβ1-42/Aβ1-40 ratio could partly compensate it. P-Tau and t-Tau were not affected by any of the tested storage conditions. For conditions involving storage at 4 °C, a correction factor of 1.081 can be applied. Diagnostic agreement was almost perfect in all conditions. Conclusions Cutoffs calculated in samples stored at −80 °C can be safely used in samples stored at −20 °C for 15–16 days or up to two days at RT and subsequent freezing at −80 °C. For samples stored at 4 °C, cutoffs would require applying a correction factor, allowing to work with the certainty of reaching the same clinical diagnosis.
{"title":"Importance of cerebrospinal fluid storage conditions for the Alzheimer’s disease diagnostics on an automated platform","authors":"Rosa Ferrer, N. Zhu, J. Arranz, I. Porcel, Shaimaa El Bounasri, Oriol Sánchez, Soraya Torres, J. Julve, A. Lleó, F. Blanco-Vaca, D. Alcolea, M. Tondo","doi":"10.1515/cclm-2022-0134","DOIUrl":"https://doi.org/10.1515/cclm-2022-0134","url":null,"abstract":"Abstract Objectives Alzheimer’s disease (AD) is considered the most common cause of dementia in older people. Cerebrospinal fluid (CSF) Aβ1-42, Aβ1-40, total Tau (t-Tau), and phospho Tau (p-Tau) are important biomarkers for the diagnosis, however, they are highly dependent on the pre-analytical conditions. Our aim was to investigate the potential influence of different storage conditions on the simultaneous quantification of these biomarkers in a fully-automated platform to accommodate easier pre-analytical conditions for laboratories. Methods CSF samples were obtained from 11 consecutive patients. Aβ1-42, Aβ1-40, p-Tau, and t-Tau were quantified using the LUMIPULSE G600II automated platform. Results Temperature and storage days significantly influenced Aβ1-42 and Aβ1-40 with concentrations decreasing with days spent at 4 °C. The use of the Aβ1-42/Aβ1-40 ratio could partly compensate it. P-Tau and t-Tau were not affected by any of the tested storage conditions. For conditions involving storage at 4 °C, a correction factor of 1.081 can be applied. Diagnostic agreement was almost perfect in all conditions. Conclusions Cutoffs calculated in samples stored at −80 °C can be safely used in samples stored at −20 °C for 15–16 days or up to two days at RT and subsequent freezing at −80 °C. For samples stored at 4 °C, cutoffs would require applying a correction factor, allowing to work with the certainty of reaching the same clinical diagnosis.","PeriodicalId":10388,"journal":{"name":"Clinical Chemistry and Laboratory Medicine (CCLM)","volume":"18 1","pages":"1058 - 1063"},"PeriodicalIF":0.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80819866","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}
Abstract The contribution of laboratory medicine in delivering value-based care depends on active cooperation and trust between pathologist and clinician. The effectiveness of medicine more in general depends in turn on active cooperation and trust between clinician and patient. From the second half of the 20th century, the art of medicine is challenged by the spread of artificial intelligence (AI) technologies, recently showing comparable performances to flesh-and-bone doctors in some diagnostic specialties. Being the principle source of data in medicine, the laboratory is a natural ground where AI technologies can disclose the best of their potential. In order to maximize the expected outcomes and minimize risks, it is crucial to define ethical requirements for data collection and interpretation by-design, clarify whether they are enhanced or challenged by specific uses of AI technologies, and preserve these data under rigorous but feasible norms. From 2018 onwards, the European Commission (EC) is making efforts to lay the foundations of sustainable AI development among European countries and partners, both from a cultural and a normative perspective. Alongside with the work of the EC, the United Kingdom provided worthy-considering complementary advice in order to put science and technology at the service of patients and doctors. In this paper we discuss the main ethical challenges associated with the use of AI technologies in pathology and laboratory medicine, and summarize the most pertaining key-points from the guidelines and frameworks before-mentioned.
{"title":"Artificial intelligence in laboratory medicine: fundamental ethical issues and normative key-points","authors":"F. Pennestrì, G. Banfi","doi":"10.1515/cclm-2022-0096","DOIUrl":"https://doi.org/10.1515/cclm-2022-0096","url":null,"abstract":"Abstract The contribution of laboratory medicine in delivering value-based care depends on active cooperation and trust between pathologist and clinician. The effectiveness of medicine more in general depends in turn on active cooperation and trust between clinician and patient. From the second half of the 20th century, the art of medicine is challenged by the spread of artificial intelligence (AI) technologies, recently showing comparable performances to flesh-and-bone doctors in some diagnostic specialties. Being the principle source of data in medicine, the laboratory is a natural ground where AI technologies can disclose the best of their potential. In order to maximize the expected outcomes and minimize risks, it is crucial to define ethical requirements for data collection and interpretation by-design, clarify whether they are enhanced or challenged by specific uses of AI technologies, and preserve these data under rigorous but feasible norms. From 2018 onwards, the European Commission (EC) is making efforts to lay the foundations of sustainable AI development among European countries and partners, both from a cultural and a normative perspective. Alongside with the work of the EC, the United Kingdom provided worthy-considering complementary advice in order to put science and technology at the service of patients and doctors. In this paper we discuss the main ethical challenges associated with the use of AI technologies in pathology and laboratory medicine, and summarize the most pertaining key-points from the guidelines and frameworks before-mentioned.","PeriodicalId":10388,"journal":{"name":"Clinical Chemistry and Laboratory Medicine (CCLM)","volume":"45 1","pages":"1867 - 1874"},"PeriodicalIF":0.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74866944","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}
R. Hasselbalch, J. Kristensen, N. Jørgensen, Nina Strandkjær, B. Alaour, S. Afzal, M. Marber, H. Bundgaard, K. Iversen
Abstract Objectives Cardiac troponin (cTn) is the biochemical gold standard for diagnosing myocardial infarction (MI). We compared the Siemens ADVIA Centaur High-Sensitivity (hs-cTnI) assay with the Siemens Ultra assay (cTnI-U). Methods Over 3 months cTnI-U and hs-cTnI were measured simultaneously at Herlev-Gentofte Hospital. Acute myocardial injury was diagnosed using the 4th universal definition. Disputed cases were adjudicated using clinical data. We compared diagnostic accuracy using area under the curve (AUC) of the receiver operating characteristic. Outliers in between-assay differences were defined as a factor-5 difference and ≥1 measurement >40 ng/L. Patients with outlier differences were invited for re-sampling and tested with serial dilution and heterophilic blocking tubes. Results From the 18th January to the 20th April 2019, 4,369 samples on 2,658 patients were included. cTnI-U measured higher concentrations than hs-cTnI (mean 23%, −52–213%), resulting in a higher frequency of acute myocardial injury, 255 (9.6%) vs. 203 (7.6%), p<0.001. This remained significant after adjudication, 212 vs 197, p<0.001. AUC for the prediction of MI for was 0.963 for cTnI-U and 0.959 for hs-cTnI, p=0.001. Outlier differences were seen in 35 (1.2%) patients, primarily with elevated hs-cTnI (n=33, 94%). On two re-samplings (median 144 and 297 days since inclusion), 16 of 20 (80%) and 11 of 11 had sustained elevation of hs-cTnI. The samples showed no signs of heterophilic antibodies. Conclusions Using hs-cTnI resulted in a subset of patients with large, discrepant elevations in concentration. These patients still had elevated hs-cTnI 6–10 months post admission but no heterophilic antibodies.
{"title":"High incidence of discrepancies in new Siemens assay – a comparison of cardiac troponin I assays","authors":"R. Hasselbalch, J. Kristensen, N. Jørgensen, Nina Strandkjær, B. Alaour, S. Afzal, M. Marber, H. Bundgaard, K. Iversen","doi":"10.1515/cclm-2022-0034","DOIUrl":"https://doi.org/10.1515/cclm-2022-0034","url":null,"abstract":"Abstract Objectives Cardiac troponin (cTn) is the biochemical gold standard for diagnosing myocardial infarction (MI). We compared the Siemens ADVIA Centaur High-Sensitivity (hs-cTnI) assay with the Siemens Ultra assay (cTnI-U). Methods Over 3 months cTnI-U and hs-cTnI were measured simultaneously at Herlev-Gentofte Hospital. Acute myocardial injury was diagnosed using the 4th universal definition. Disputed cases were adjudicated using clinical data. We compared diagnostic accuracy using area under the curve (AUC) of the receiver operating characteristic. Outliers in between-assay differences were defined as a factor-5 difference and ≥1 measurement >40 ng/L. Patients with outlier differences were invited for re-sampling and tested with serial dilution and heterophilic blocking tubes. Results From the 18th January to the 20th April 2019, 4,369 samples on 2,658 patients were included. cTnI-U measured higher concentrations than hs-cTnI (mean 23%, −52–213%), resulting in a higher frequency of acute myocardial injury, 255 (9.6%) vs. 203 (7.6%), p<0.001. This remained significant after adjudication, 212 vs 197, p<0.001. AUC for the prediction of MI for was 0.963 for cTnI-U and 0.959 for hs-cTnI, p=0.001. Outlier differences were seen in 35 (1.2%) patients, primarily with elevated hs-cTnI (n=33, 94%). On two re-samplings (median 144 and 297 days since inclusion), 16 of 20 (80%) and 11 of 11 had sustained elevation of hs-cTnI. The samples showed no signs of heterophilic antibodies. Conclusions Using hs-cTnI resulted in a subset of patients with large, discrepant elevations in concentration. These patients still had elevated hs-cTnI 6–10 months post admission but no heterophilic antibodies.","PeriodicalId":10388,"journal":{"name":"Clinical Chemistry and Laboratory Medicine (CCLM)","volume":"22 1","pages":"921 - 929"},"PeriodicalIF":0.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77040682","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}
{"title":"Unexpectedly low tacrolimus concentrations attributed to inappropriately labeled water container from the instrument manufacturer","authors":"Erik Ames, R. Bowen","doi":"10.1515/cclm-2022-0204","DOIUrl":"https://doi.org/10.1515/cclm-2022-0204","url":null,"abstract":"","PeriodicalId":10388,"journal":{"name":"Clinical Chemistry and Laboratory Medicine (CCLM)","volume":"197 1","pages":"e159 - e160"},"PeriodicalIF":0.0,"publicationDate":"2022-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75900354","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}
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