Pub Date : 2024-10-02DOI: 10.1093/clinchem/hvae106.376
M A Nicklas, N A Baumann, L M Leonard, L A Rossini, D R Block
Background Bicarbonate stability in serum depends on time, exposure to air, temperature, tube size and sample volume. With implementation of Cobas Connection Module (CCM) automation, the workflow for bicarbonate measurement needed to be re-evaluated. The aim of this study was to determine bicarbonate stability in filled 3.5 mL and 5 mL serum-separator tubes (SSTs) and capped and uncapped aliquot tubes on the CCM automation. Methods Bicarbonate was measured on a Cobas c701 (Roche Diagnostics) at various time points. SSTs (n=8) were centrifuged 6 min at 1649g ∼30 min post-collection. Serum was aliquoted (1 mL) into capped or uncapped tubes and kept ambient (15-25°C) on the CCM track for 0, 60, 90, 150, 180, 240 and 300 minutes (n=2 per time point). Primary SSTs (5mL n=4, and 3.5mL n=5) were uncapped on the CCM track and bicarbonate measured at baseline and 30 minute intervals through 6.5 hours. An absolute difference of +/- 4 mmol/L from baseline was considered acceptable. Results Bicarbonate concentrations decrease with time at rates dependent on whether the aliquot tube is capped or uncapped or the SST is 3.5 mL or 5 mL (Figure 1).Figure 1.Average decrease in bicarbonate concentration with time for capped aliquot tubes (black square), uncapped aliquot tubes (red circle), 3.5 mL serum separator tube (blue up triangle), 5 mL serum separator tube (green down triangle). Bars represent +/- 1SD. Conclusions Bicarbonate in serum is stable for testing for 2.5 hours in uncapped 1 mL aliquot tubes, 3.5 hours in capped 1 mL aliquot tubes, 3.5 hours in uncapped full 3.5 mL SST tubes and 6 hours in uncapped full 5 mL SST tubes at ambient temperatures (15-25°C). Bicarbonate testing can be accommodated by total laboratory automation but processes such as add-ons and retesting must be done with caution.
{"title":"B-012 Total Laboratory Automation: Assessing Serum Bicarbonate Stability Under Conditions Experienced Using the Roche Diagnostics Cobas Connection Module","authors":"M A Nicklas, N A Baumann, L M Leonard, L A Rossini, D R Block","doi":"10.1093/clinchem/hvae106.376","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.376","url":null,"abstract":"Background Bicarbonate stability in serum depends on time, exposure to air, temperature, tube size and sample volume. With implementation of Cobas Connection Module (CCM) automation, the workflow for bicarbonate measurement needed to be re-evaluated. The aim of this study was to determine bicarbonate stability in filled 3.5 mL and 5 mL serum-separator tubes (SSTs) and capped and uncapped aliquot tubes on the CCM automation. Methods Bicarbonate was measured on a Cobas c701 (Roche Diagnostics) at various time points. SSTs (n=8) were centrifuged 6 min at 1649g ∼30 min post-collection. Serum was aliquoted (1 mL) into capped or uncapped tubes and kept ambient (15-25°C) on the CCM track for 0, 60, 90, 150, 180, 240 and 300 minutes (n=2 per time point). Primary SSTs (5mL n=4, and 3.5mL n=5) were uncapped on the CCM track and bicarbonate measured at baseline and 30 minute intervals through 6.5 hours. An absolute difference of +/- 4 mmol/L from baseline was considered acceptable. Results Bicarbonate concentrations decrease with time at rates dependent on whether the aliquot tube is capped or uncapped or the SST is 3.5 mL or 5 mL (Figure 1).Figure 1.Average decrease in bicarbonate concentration with time for capped aliquot tubes (black square), uncapped aliquot tubes (red circle), 3.5 mL serum separator tube (blue up triangle), 5 mL serum separator tube (green down triangle). Bars represent +/- 1SD. Conclusions Bicarbonate in serum is stable for testing for 2.5 hours in uncapped 1 mL aliquot tubes, 3.5 hours in capped 1 mL aliquot tubes, 3.5 hours in uncapped full 3.5 mL SST tubes and 6 hours in uncapped full 5 mL SST tubes at ambient temperatures (15-25°C). Bicarbonate testing can be accommodated by total laboratory automation but processes such as add-ons and retesting must be done with caution.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"220 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142362987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1093/clinchem/hvae106.384
M Ruiz-Alvarez, S Lapeña-Garcia, S Garcia-Valdecasas, T Costales-Lucia, J De La Rubia-Maestu, M Barrionuevo-Gonzalez
Background Method intercomparison is an essential requirement in Clinical Laboratories before changing a method or instrument to verify the interchangeability of results. After validating a new Siemens device, the CI®, we conducted an intercomparison study with the Atellica Solution® for T4 free (T4L), β-HCG total, and PSA total assays. Objectives To check the interchangeability of results between the methods of T4L, β-HCG total, and PSA total, as determined on the Atellica Solution® and CI® analyzers, to evaluate the behavior of both equipment in our laboratory as a single virtual team. Methods A total of 120 serum samples from patients with T4L values between 0.41 and 7.5 ng/dL, β-HCG total between 0.5 and 1000 mIU/mL, and PSA total between 0.01 and 78.4 ng/mL were processed on both analyzers. Passing-Bablok regression, Bland-Altman analysis, and Pearson correlation coefficient were used to evaluate the sample size. Results are expressed with a 95% confidence interval. The intercomparison study was conducted using Method Validator Version 1.19. Results See table Conclusions After evaluating the results, we conclude that the Atellica Solution® and CI® analyzers behave as a single virtual team for the T4L, β-HCG total, and PSA total assays. Although there are systematic errors, they do not exceed the quality specifications established in our laboratory, based on the Total Error allowable according to Biological Variability.
{"title":"B-020 Study of Method Intercomparison between Atellica Solution® and CI® Analyzers for T4L, β-HCG Total, and PSA Total","authors":"M Ruiz-Alvarez, S Lapeña-Garcia, S Garcia-Valdecasas, T Costales-Lucia, J De La Rubia-Maestu, M Barrionuevo-Gonzalez","doi":"10.1093/clinchem/hvae106.384","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.384","url":null,"abstract":"Background Method intercomparison is an essential requirement in Clinical Laboratories before changing a method or instrument to verify the interchangeability of results. After validating a new Siemens device, the CI®, we conducted an intercomparison study with the Atellica Solution® for T4 free (T4L), β-HCG total, and PSA total assays. Objectives To check the interchangeability of results between the methods of T4L, β-HCG total, and PSA total, as determined on the Atellica Solution® and CI® analyzers, to evaluate the behavior of both equipment in our laboratory as a single virtual team. Methods A total of 120 serum samples from patients with T4L values between 0.41 and 7.5 ng/dL, β-HCG total between 0.5 and 1000 mIU/mL, and PSA total between 0.01 and 78.4 ng/mL were processed on both analyzers. Passing-Bablok regression, Bland-Altman analysis, and Pearson correlation coefficient were used to evaluate the sample size. Results are expressed with a 95% confidence interval. The intercomparison study was conducted using Method Validator Version 1.19. Results See table Conclusions After evaluating the results, we conclude that the Atellica Solution® and CI® analyzers behave as a single virtual team for the T4L, β-HCG total, and PSA total assays. Although there are systematic errors, they do not exceed the quality specifications established in our laboratory, based on the Total Error allowable according to Biological Variability.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"76 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142362988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1093/clinchem/hvae106.375
S Garcia-Valdecasas, S Lapeña-Garcia, M Ruiz-Alvarez, Y Fernandez-Verduras, T Costales-Lucia, J De La Rubia-Maestu, M Barrionuevo-Gonzalez
Background The objective of this study is to verify if the results of the Amylase and Glucose methods, measured by two different analyzers: Atellica Solution® and CI® (Siemens Healthineers), are interchangeable. Methods To carry out the intermethod comparison study of the Amylase and Glucose methods, 40 patient samples were selected for each assay, with concentrations across the entire measurement range. Statistical analysis was performed using Method Validator v.19 software, through Bland-Altman mean difference analysis and Passing-Bablok regression. Statistics are expressed with their 95% confidence intervals (CI). Results AMYLASE: After analyzing the Bland-Altman differences, a statistically significant systematic error was found, as the mean difference between the results obtained by Atellica Solution® and CI® was 28.1 with a 95% CI that does not include the null value, with higher results in CI®. Regarding the Passing Bablok analysis, systematic differences, both proportional and constant, were observed as the confidence interval of the intercept does not include the zero value, and that of the slope does not include the value 1.GLUCOSE: After Bland-Altman analysis, a systematic error was found, as the mean difference between the results obtained by Atellica Solution® and CI® was 2.1, with slightly higher results in CI®. Regarding the Passing Bablok analysis, there were no systematic differences of constant type since the confidence interval of the intercept includes the zero value, and a slight proportional systematic error based on the slope as its 95% CI does not include the value 1. Conclusions After evaluating the results, it is concluded that the Atellica Solution® and CI® analyzers are not interchangeable for the Amylase assay, so new reference values should be established. For the Glucose assay, both analyzers are interchangeable as the observed difference does not exceed our quality specification.
{"title":"B-011 Intermethod Comparison Verification between Atellica Solution® and CI® Analyzers for Amylase and Glucose Methods","authors":"S Garcia-Valdecasas, S Lapeña-Garcia, M Ruiz-Alvarez, Y Fernandez-Verduras, T Costales-Lucia, J De La Rubia-Maestu, M Barrionuevo-Gonzalez","doi":"10.1093/clinchem/hvae106.375","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.375","url":null,"abstract":"Background The objective of this study is to verify if the results of the Amylase and Glucose methods, measured by two different analyzers: Atellica Solution® and CI® (Siemens Healthineers), are interchangeable. Methods To carry out the intermethod comparison study of the Amylase and Glucose methods, 40 patient samples were selected for each assay, with concentrations across the entire measurement range. Statistical analysis was performed using Method Validator v.19 software, through Bland-Altman mean difference analysis and Passing-Bablok regression. Statistics are expressed with their 95% confidence intervals (CI). Results AMYLASE: After analyzing the Bland-Altman differences, a statistically significant systematic error was found, as the mean difference between the results obtained by Atellica Solution® and CI® was 28.1 with a 95% CI that does not include the null value, with higher results in CI®. Regarding the Passing Bablok analysis, systematic differences, both proportional and constant, were observed as the confidence interval of the intercept does not include the zero value, and that of the slope does not include the value 1.GLUCOSE: After Bland-Altman analysis, a systematic error was found, as the mean difference between the results obtained by Atellica Solution® and CI® was 2.1, with slightly higher results in CI®. Regarding the Passing Bablok analysis, there were no systematic differences of constant type since the confidence interval of the intercept includes the zero value, and a slight proportional systematic error based on the slope as its 95% CI does not include the value 1. Conclusions After evaluating the results, it is concluded that the Atellica Solution® and CI® analyzers are not interchangeable for the Amylase assay, so new reference values should be established. For the Glucose assay, both analyzers are interchangeable as the observed difference does not exceed our quality specification.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"37 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142362774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1093/clinchem/hvae106.351
G Iacovetti, N Tokunaga, M Peevler, J Ragar, G J Sommer, U Y Schaff
Background While solutions enabling at-home self-collection of capillary blood samples are maturing, many analytes require blood separation and controlled shipping temperatures for stable analysis in centralized laboratories. Here we present results of a pilot lay user study evaluating usability and specimen quality of at-home blood collection with centrifugation and refrigerated shipping of capillary serum specimens. Methods N=45 consented subjects were mailed kits including supplies for a capillary blood self-collection using a Tasso+™ device, a Labcorp TrueTherm™ reusable shipper containing a temperature tracker, a Labcorp TrueSpin™ battery-powered centrifuge, written instructions, and a usability survey. Subjects independently followed the instructions for blood collection, separation, and thermal protection and returned the kits to Labcorp via overnight shipping. Received kits were evaluated for correct return, volume of blood collected, volume of serum, visual hemolysis, and temperature throughout shipment. Results Of the n=45 consented subjects, 39 subjects returned the kits, one subject unsuccessfully attempted to collect blood two times, and the remaining five subjects did not return the kits. Primary analysis parameters are outlined in Table 1. Conclusions Untrained subjects were able to collect their own capillary blood samples, process them, and ship them using the investigational home collection kits. While kit return can be a challenge with home collection, the vast majority of subjects were able to return a testable sample. Combining blood separation prior to shipment using the Labcorp TrueSpin centrifuge and temperature control with the reusable Labcorp TrueTherm device successfully protected samples from hemolysis. These results indicate that such kits are a promising at-home blood collection method and may increase test accuracy and menu availability for sensitive analytes.
{"title":"A-357 Evaluation of a home kit for lay user collection, centrifugation, and refrigeration of capillary blood specimens","authors":"G Iacovetti, N Tokunaga, M Peevler, J Ragar, G J Sommer, U Y Schaff","doi":"10.1093/clinchem/hvae106.351","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.351","url":null,"abstract":"Background While solutions enabling at-home self-collection of capillary blood samples are maturing, many analytes require blood separation and controlled shipping temperatures for stable analysis in centralized laboratories. Here we present results of a pilot lay user study evaluating usability and specimen quality of at-home blood collection with centrifugation and refrigerated shipping of capillary serum specimens. Methods N=45 consented subjects were mailed kits including supplies for a capillary blood self-collection using a Tasso+™ device, a Labcorp TrueTherm™ reusable shipper containing a temperature tracker, a Labcorp TrueSpin™ battery-powered centrifuge, written instructions, and a usability survey. Subjects independently followed the instructions for blood collection, separation, and thermal protection and returned the kits to Labcorp via overnight shipping. Received kits were evaluated for correct return, volume of blood collected, volume of serum, visual hemolysis, and temperature throughout shipment. Results Of the n=45 consented subjects, 39 subjects returned the kits, one subject unsuccessfully attempted to collect blood two times, and the remaining five subjects did not return the kits. Primary analysis parameters are outlined in Table 1. Conclusions Untrained subjects were able to collect their own capillary blood samples, process them, and ship them using the investigational home collection kits. While kit return can be a challenge with home collection, the vast majority of subjects were able to return a testable sample. Combining blood separation prior to shipment using the Labcorp TrueSpin centrifuge and temperature control with the reusable Labcorp TrueTherm device successfully protected samples from hemolysis. These results indicate that such kits are a promising at-home blood collection method and may increase test accuracy and menu availability for sensitive analytes.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"1 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142362938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1093/clinchem/hvae106.345
S J Bennett, J S Link, A Dolence, Z D Call, B Martinez, C S Henry
Background Healthcare professionals must choose between sensitivity and ease-of-use in diagnostics, particularly for diseases like COVID-19 and strep throat. Traditional enzyme-linked immunosorbent assays (ELISAs) are sensitive but are manually intensive and lengthy. Lateral flow assays (LFAs) are an alternative with low cost, ease-of-use, and rapid results; but LFAs suffer from low sensitivity. Burst Diagnostics presents a groundbreaking solution with the capillary-driven immunoassay (CaDI), a novel microfluidic device delivering sensitivity comparable to ELISA with the ease of LFAs. Methods The CaDI is made of flow channels defined by layered transparency and adhesive sheets containing reagent pads with HRP-conjugated antibody and luminol. The system requires only a sample addition step by the user. Sample flow initiates sequential steps of a sandwich ELISA, fully automated by the device, to provide a chemiluminescent signal in 10 minutes or less, depending on sample matrix. Results We have demonstrated success with preliminary studies for the detection of SARS-CoV-2 nucleocapsid protein (NP) and group A streptococcus (GAS). Detection of NP was achieved by assembling and optimizing COVID-19 CaDI’s using anti-NP antibodies. Then, spiked nasal swab samples were tested ranging from 10 to 1000 PFU/mL with positive detection as low as 10 PFU/mL, much less than the same samples in a traditional LFA (see figure). Additionally, we have demonstrated successful detection of GAS in optimized buffer conditions up to 100-fold less than commonly used LFAs. Finally, multiplexed CaDI’s increase throughput and cost-effectiveness in the point-of-care setting. Conclusions The CaDI platform bridges the ease of LFAs and sensitivity/specificity of laboratory tests. Currently, the CaDI can detect SARS-CoV-2 NP and GAS with higher sensitivity than existing LFAs. Development is underway for a reader to accompany the CaDI and further simplify the test. Importantly, the potential targets for detection are immense due to the sensitivity, simplicity, and adaptability of the platform.
{"title":"A-351 Versatile and Sensitive Microfluidic Immunoassay for Improved Point-of-Care Diagnostics","authors":"S J Bennett, J S Link, A Dolence, Z D Call, B Martinez, C S Henry","doi":"10.1093/clinchem/hvae106.345","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.345","url":null,"abstract":"Background Healthcare professionals must choose between sensitivity and ease-of-use in diagnostics, particularly for diseases like COVID-19 and strep throat. Traditional enzyme-linked immunosorbent assays (ELISAs) are sensitive but are manually intensive and lengthy. Lateral flow assays (LFAs) are an alternative with low cost, ease-of-use, and rapid results; but LFAs suffer from low sensitivity. Burst Diagnostics presents a groundbreaking solution with the capillary-driven immunoassay (CaDI), a novel microfluidic device delivering sensitivity comparable to ELISA with the ease of LFAs. Methods The CaDI is made of flow channels defined by layered transparency and adhesive sheets containing reagent pads with HRP-conjugated antibody and luminol. The system requires only a sample addition step by the user. Sample flow initiates sequential steps of a sandwich ELISA, fully automated by the device, to provide a chemiluminescent signal in 10 minutes or less, depending on sample matrix. Results We have demonstrated success with preliminary studies for the detection of SARS-CoV-2 nucleocapsid protein (NP) and group A streptococcus (GAS). Detection of NP was achieved by assembling and optimizing COVID-19 CaDI’s using anti-NP antibodies. Then, spiked nasal swab samples were tested ranging from 10 to 1000 PFU/mL with positive detection as low as 10 PFU/mL, much less than the same samples in a traditional LFA (see figure). Additionally, we have demonstrated successful detection of GAS in optimized buffer conditions up to 100-fold less than commonly used LFAs. Finally, multiplexed CaDI’s increase throughput and cost-effectiveness in the point-of-care setting. Conclusions The CaDI platform bridges the ease of LFAs and sensitivity/specificity of laboratory tests. Currently, the CaDI can detect SARS-CoV-2 NP and GAS with higher sensitivity than existing LFAs. Development is underway for a reader to accompany the CaDI and further simplify the test. Importantly, the potential targets for detection are immense due to the sensitivity, simplicity, and adaptability of the platform.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"26 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142362970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1093/clinchem/hvae106.369
S Kuklok, R Lareau, J Thomforde, T Her, A Young, T Thompson, M Tornquist, A Bagley, H Kubista, J Johnson, B Bolstad, K Walt, D Lovett, M Holland, J Mah, W Nelson, J Lengfeld, M Quin, B Bilyeu, C Knutson, M Posnansky, N Malikowski-Hoffarth, K Soller, M Szabo, C Carlson
Background The Beckman Coulter DxI 9000 Immunoassay Analyzer* includes new technology that improves assay sensitivity capabilities. Such technological advancements include the Lumi-Phos PRO chemiluminescent substrate, a new luminometer, and improved low-volume pipetting capabilities. These enhancements afford opportunities to develop immunoassays using reduced sample and reagent volumes, conserving precious patient samples, minimizing the carbon footprint of plastic packaging, and increasing the number of tests per reagent pack. Studies are presented herein for the Access TSH (3rd IS), Access βhCG (5th IS), and Access Hybritech Total PSA assays to evaluate analytical performance when using decreased sample/reagent volumes on the DxI 9000 analyzer. *The official name is DxI 9000 Access Immunoassay Analyzer. Methods To assess performance when using proportionally reduced sample/reagent volumes on the DxI 9000 analyzer compared to standard sample/reagent volumes on the Access 2 Immunoassay System, within-laboratory precision was evaluated following CLSI EP05-A3, limit of quantitation (LoQ) was estimated following CLSI EP17-A2, and accuracy was assessed following CLSI EP09c, 3rd ed. Results Results of sensitivity studies are summarized in the table below for assays using reduced sample/reagent volumes on the DxI 9000 analyzer compared to standard volumes on the Access 2 system. Maximum observed LoQ improved 1.4- to 3-fold on the DxI 9000 analyzer, despite employing ∼50% reduction of sample/reagents. Precision and accuracy studies also showed acceptable performance. Conclusions The data herein provide evidence for maintained analytical performance goals when using reduced sample and reagent volumes for assays on the DxI 9000 analyzer. The additional sensitivity capability of the DxI 9000 analyzer can be used to reduce the volume of sample and reagents, conserving patient samples and reducing packaging per test. The pipetting accuracy and detection capabilities of the DxI 9000 analyzer provide opportunities for immunoassay developers to drive both improved low-end performance and conservation of resources.
{"title":"B-005 Improved Sensitivity on the Beckman Coulter DxI 9000 Immunoassay Analyzer* Enables Reduction of Required Sample and Reagent Volumes for Immunoassays","authors":"S Kuklok, R Lareau, J Thomforde, T Her, A Young, T Thompson, M Tornquist, A Bagley, H Kubista, J Johnson, B Bolstad, K Walt, D Lovett, M Holland, J Mah, W Nelson, J Lengfeld, M Quin, B Bilyeu, C Knutson, M Posnansky, N Malikowski-Hoffarth, K Soller, M Szabo, C Carlson","doi":"10.1093/clinchem/hvae106.369","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.369","url":null,"abstract":"Background The Beckman Coulter DxI 9000 Immunoassay Analyzer* includes new technology that improves assay sensitivity capabilities. Such technological advancements include the Lumi-Phos PRO chemiluminescent substrate, a new luminometer, and improved low-volume pipetting capabilities. These enhancements afford opportunities to develop immunoassays using reduced sample and reagent volumes, conserving precious patient samples, minimizing the carbon footprint of plastic packaging, and increasing the number of tests per reagent pack. Studies are presented herein for the Access TSH (3rd IS), Access βhCG (5th IS), and Access Hybritech Total PSA assays to evaluate analytical performance when using decreased sample/reagent volumes on the DxI 9000 analyzer. *The official name is DxI 9000 Access Immunoassay Analyzer. Methods To assess performance when using proportionally reduced sample/reagent volumes on the DxI 9000 analyzer compared to standard sample/reagent volumes on the Access 2 Immunoassay System, within-laboratory precision was evaluated following CLSI EP05-A3, limit of quantitation (LoQ) was estimated following CLSI EP17-A2, and accuracy was assessed following CLSI EP09c, 3rd ed. Results Results of sensitivity studies are summarized in the table below for assays using reduced sample/reagent volumes on the DxI 9000 analyzer compared to standard volumes on the Access 2 system. Maximum observed LoQ improved 1.4- to 3-fold on the DxI 9000 analyzer, despite employing ∼50% reduction of sample/reagents. Precision and accuracy studies also showed acceptable performance. Conclusions The data herein provide evidence for maintained analytical performance goals when using reduced sample and reagent volumes for assays on the DxI 9000 analyzer. The additional sensitivity capability of the DxI 9000 analyzer can be used to reduce the volume of sample and reagents, conserving patient samples and reducing packaging per test. The pipetting accuracy and detection capabilities of the DxI 9000 analyzer provide opportunities for immunoassay developers to drive both improved low-end performance and conservation of resources.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"58 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142362981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1093/clinchem/hvae106.530
I De Biase, M Miller, L M Zuromski, S Steckel, P P Vachali, T Yuzyuk
Background Plasmalogens are critical membrane structural components that are mainly generated by de novo synthesis starting in peroxisomes. Hence, patients with defects in peroxisome biogenesis (PBD) exhibit markedly reduced plasmalogen levels. Plasmalogen ratios are traditionally measured by gas chromatography-mass spectrometry (GC-MS); however, this method entails a lengthy sample extraction and derivatization and does not report concentrations of individual plasmalogen species. We have developed a robust and easy-to-implement liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify the 18 most abundant ethanolamine plasmalogen (PlsEtn) species in packed red blood cells (RBCs). However, no reference intervals have been published for individual PlsEtn. Here, we describe the establishment of age-specific reference intervals for individual PlsEtn species and their total values (16:0, 18:0, 18:1 species, and total plasmalogens). Methods Plasmalogens were extracted using methanol containing two labeled internal standards, shaking for one hour at room temperature. Chromatographic separation was performed using an Acquity Premier BEH C18 UPLC column with a binary gradient of 5 mM ammonium acetate in water:methanol (15:85) and 5 mM ammonium acetate in methanol. Analysis was performed using a XEVO TQ-XS Mass Spectrometer with Ultra-High Performance Liquid Chromatography (Waters) in multiple reaction monitoring mode. Eighteen PlsEtn species were quantified using four commercially available standards; additionally, totals were calculated for 16:0, 18:0 or 18:1 species, and for total plasmalogens. Reference intervals were established using 376 RBCs from self-reported healthy volunteers and de-identified clinical samples referred for unrelated testing (182 females and 194 males; range 0 to 88 years). Data was analyzed using the R programming language. The study was approved by the Institutional Review Board of the University of Utah. Results Initial age groups were identified using a model-based clustering algorithm followed by iterative Harris-Boyd analysis. Finally, the adjacent groups were merged if their means differed by less than 10%. Once the final age groups were partitioned, data in each individual age group were analyzed using parametric or non-parametric statistics to determine reference intervals (95%, with 90%confidence intervals). PlsEtn species displayed the lowest concentration in the first few months of life, which increased in childhood until adolescence or adulthood (depending on PlsEtn). For most species, the concentrations increased over time reaching a plateau between 18 and 48 years of age, and then starting to decrease. The total values followed the same trend, with neonates showing significantly lower values compared to other age groups. Conclusions We applied a novel statistical approach to identify age groups and determine age-specific reference intervals for 18 individual PlsEtn in RBC and their totals. Lackin
{"title":"B-170 Age-Specific reference intervals for ethanolamine plasmalogen species in red blood cells using liquid chromatography tandem mass spectrometry","authors":"I De Biase, M Miller, L M Zuromski, S Steckel, P P Vachali, T Yuzyuk","doi":"10.1093/clinchem/hvae106.530","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.530","url":null,"abstract":"Background Plasmalogens are critical membrane structural components that are mainly generated by de novo synthesis starting in peroxisomes. Hence, patients with defects in peroxisome biogenesis (PBD) exhibit markedly reduced plasmalogen levels. Plasmalogen ratios are traditionally measured by gas chromatography-mass spectrometry (GC-MS); however, this method entails a lengthy sample extraction and derivatization and does not report concentrations of individual plasmalogen species. We have developed a robust and easy-to-implement liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify the 18 most abundant ethanolamine plasmalogen (PlsEtn) species in packed red blood cells (RBCs). However, no reference intervals have been published for individual PlsEtn. Here, we describe the establishment of age-specific reference intervals for individual PlsEtn species and their total values (16:0, 18:0, 18:1 species, and total plasmalogens). Methods Plasmalogens were extracted using methanol containing two labeled internal standards, shaking for one hour at room temperature. Chromatographic separation was performed using an Acquity Premier BEH C18 UPLC column with a binary gradient of 5 mM ammonium acetate in water:methanol (15:85) and 5 mM ammonium acetate in methanol. Analysis was performed using a XEVO TQ-XS Mass Spectrometer with Ultra-High Performance Liquid Chromatography (Waters) in multiple reaction monitoring mode. Eighteen PlsEtn species were quantified using four commercially available standards; additionally, totals were calculated for 16:0, 18:0 or 18:1 species, and for total plasmalogens. Reference intervals were established using 376 RBCs from self-reported healthy volunteers and de-identified clinical samples referred for unrelated testing (182 females and 194 males; range 0 to 88 years). Data was analyzed using the R programming language. The study was approved by the Institutional Review Board of the University of Utah. Results Initial age groups were identified using a model-based clustering algorithm followed by iterative Harris-Boyd analysis. Finally, the adjacent groups were merged if their means differed by less than 10%. Once the final age groups were partitioned, data in each individual age group were analyzed using parametric or non-parametric statistics to determine reference intervals (95%, with 90%confidence intervals). PlsEtn species displayed the lowest concentration in the first few months of life, which increased in childhood until adolescence or adulthood (depending on PlsEtn). For most species, the concentrations increased over time reaching a plateau between 18 and 48 years of age, and then starting to decrease. The total values followed the same trend, with neonates showing significantly lower values compared to other age groups. Conclusions We applied a novel statistical approach to identify age groups and determine age-specific reference intervals for 18 individual PlsEtn in RBC and their totals. Lackin","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"23 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1093/clinchem/hvae106.492
Z BROOKS
Background Sigma measures the number of SDs (z-value) from the existing sample mean to the nearest analytical performance standard or allowable error limit. Authors and software programs often measure sigma metrics for each QC sample but use an average sigma to compare methods and select QC strategies. That practice leads to dramatic over or under-estimation of the number of errors reported and the selection of inappropriate QC strategies. Methods Data samples were created to produce sigma values of 3.0, 4.5, and 6.0. Microsoft Excel function NORMSDIST was used to convert sigma to percent to number of errors per million patients. NORMSINV was used to convert the number of errors per million patients to sigma. Results A. Six sigma represents a method with a failure rate of 0.000001% or 0.001 failures of ASP/TEa per million patients. B. Three sigma represents a method with a failure rate of 0.135 percent or 1,350 failures of ASP/TEa per million patients. C. While the average sigma value of samples A and B was 4.5s, the average error rate was 0.0675 percent or 675 failures of ASP/TEa per million patients. D. An error rate was 0.0675 percent converts with the NORMSINV function to a sigma of 3.21. E. A true 4.5 sigma method would have a failure rate of 0.00034 percent or 3.4 failures of ASP/TEa per million patients. Conclusions Sigma studies that present an average sigma value underestimate the true number of errors reported. It would be more scientifically correct to either report the number of errors reported or to report the average sigma value based on the average number of errors. Laboratory professionals should interpret sigma studies and publications cautiously if a single sigma is used to represent two or more data sets.
{"title":"B-131 The fallacy of average sigma levels from mixed sample levels","authors":"Z BROOKS","doi":"10.1093/clinchem/hvae106.492","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.492","url":null,"abstract":"Background Sigma measures the number of SDs (z-value) from the existing sample mean to the nearest analytical performance standard or allowable error limit. Authors and software programs often measure sigma metrics for each QC sample but use an average sigma to compare methods and select QC strategies. That practice leads to dramatic over or under-estimation of the number of errors reported and the selection of inappropriate QC strategies. Methods Data samples were created to produce sigma values of 3.0, 4.5, and 6.0. Microsoft Excel function NORMSDIST was used to convert sigma to percent to number of errors per million patients. NORMSINV was used to convert the number of errors per million patients to sigma. Results A. Six sigma represents a method with a failure rate of 0.000001% or 0.001 failures of ASP/TEa per million patients. B. Three sigma represents a method with a failure rate of 0.135 percent or 1,350 failures of ASP/TEa per million patients. C. While the average sigma value of samples A and B was 4.5s, the average error rate was 0.0675 percent or 675 failures of ASP/TEa per million patients. D. An error rate was 0.0675 percent converts with the NORMSINV function to a sigma of 3.21. E. A true 4.5 sigma method would have a failure rate of 0.00034 percent or 3.4 failures of ASP/TEa per million patients. Conclusions Sigma studies that present an average sigma value underestimate the true number of errors reported. It would be more scientifically correct to either report the number of errors reported or to report the average sigma value based on the average number of errors. Laboratory professionals should interpret sigma studies and publications cautiously if a single sigma is used to represent two or more data sets.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"53 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1093/clinchem/hvae106.494
A I Corominas, G Casal, F Vommaro, S Balconi, A Damiano
Background An association between uric acid and kidney disease, glucose intolerance, high blood pressure, metabolic syndrome and cardiovascular disease has been recognized. It is the obligation of the Clinical Laboratory to have valid reference intervals (RI) for this marker. Each particular population has genetics and a diet that represents it, which cannot be extrapolated in many cases. The difficulty and high cost of using direct methods for its establishment drive us to use the existing data in our electronic archive retrospectively. Objective: to describe the range of uric acid values in adult outpatients treated at the Posadas Hospital during the year 2022. Evaluate the influence of gender and age range on the observed values. Methods A retrospective observational approach was carried out from the System database Laboratory Informatics (SIL), Roche Infinity, from the year 2022. The data corresponding to all adult outpatient patients treated in the service were processed. Analytical System: Roche Cobas 6000, Uricase-Oxidase method. Exclusion criteria: oncology patients, kidney patients, diabetics, hyperglycemic patients, obstetric patients, hormonal patients, treated in wards and referred patients. Outliers excluded by Tukey method. The statistical treatment was carried out with the SPSS 17.0 program. Results We worked with 91922 data groups. Hence 12331 of uric acid. After meeting the exclusion criteria: 3899, of which 2289 (3.96 ± 1.05 mg/dl) correspond to women < 50 years , 747 (4.36 ± 1.15 mg/dl at ≥ 50 years and 863 (5.59 ± 1.33 mg/dl) men, all with normal distributions. Applying ANOVA and Student's test it was possible to verify in addition to the described significant difference between sexes, a difference between the 2 age groups of women (p<0.01) which is not equal to that of men in women ≥ 50 years of age. Conclusions A more extensive study is necessary to define own reference ranges that enable the early alarm guidelines, especially in the group of women < 50 years of age. This will allow an adequate evaluation of risk and evolution of patients. The application of Indirect Methods will make it possible to exclude values corresponding to underlying pathologies not registered in the SIL.
{"title":"B-133 Uric acid: A description of the values found in adult patients treated during 2022 in a High Complexity Hospital","authors":"A I Corominas, G Casal, F Vommaro, S Balconi, A Damiano","doi":"10.1093/clinchem/hvae106.494","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.494","url":null,"abstract":"Background An association between uric acid and kidney disease, glucose intolerance, high blood pressure, metabolic syndrome and cardiovascular disease has been recognized. It is the obligation of the Clinical Laboratory to have valid reference intervals (RI) for this marker. Each particular population has genetics and a diet that represents it, which cannot be extrapolated in many cases. The difficulty and high cost of using direct methods for its establishment drive us to use the existing data in our electronic archive retrospectively. Objective: to describe the range of uric acid values in adult outpatients treated at the Posadas Hospital during the year 2022. Evaluate the influence of gender and age range on the observed values. Methods A retrospective observational approach was carried out from the System database Laboratory Informatics (SIL), Roche Infinity, from the year 2022. The data corresponding to all adult outpatient patients treated in the service were processed. Analytical System: Roche Cobas 6000, Uricase-Oxidase method. Exclusion criteria: oncology patients, kidney patients, diabetics, hyperglycemic patients, obstetric patients, hormonal patients, treated in wards and referred patients. Outliers excluded by Tukey method. The statistical treatment was carried out with the SPSS 17.0 program. Results We worked with 91922 data groups. Hence 12331 of uric acid. After meeting the exclusion criteria: 3899, of which 2289 (3.96 ± 1.05 mg/dl) correspond to women &lt; 50 years , 747 (4.36 ± 1.15 mg/dl at ≥ 50 years and 863 (5.59 ± 1.33 mg/dl) men, all with normal distributions. Applying ANOVA and Student's test it was possible to verify in addition to the described significant difference between sexes, a difference between the 2 age groups of women (p&lt;0.01) which is not equal to that of men in women ≥ 50 years of age. Conclusions A more extensive study is necessary to define own reference ranges that enable the early alarm guidelines, especially in the group of women &lt; 50 years of age. This will allow an adequate evaluation of risk and evolution of patients. The application of Indirect Methods will make it possible to exclude values corresponding to underlying pathologies not registered in the SIL.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"23 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1093/clinchem/hvae106.634
J O Oyelakin-Ogunbileje, S T Oyelakin, R V Sadagopa
Background Metal-contaminated soil poses significant health risks to kids because they are more sensitive to heavy metal exposure in the environment. Studies have shown that continuous exposure to metals can increase the risk of metal accumulation in blood and various body organs. This study determines the levels of some toxic metals in various playgrounds in our community. Methods We determined the levels of lead (Pb), chromium (Cr), cadmium (Cd), and copper (Cu) in six playgrounds (parks) (T-RP, T-GP, T-TX, L-HH, L-WH, L-SPLX) using graphite furnace atomic absorption spectrophotometry (GF-AAS) technique. Soil samples were collected at least one foot below the soil surface, and metal was extracted using ultra-pure nitric before analysis using GF-AAS. Data were analyzed using analysis of variance (ANOVA). Results The results showed significant detectable levels of the metals in all playgrounds evaluated in this study. L-WH Park in League City has the highest detectable levels of Pb (12.43 ± 46 mg/Kg, P<0.05) compared to other children playgrounds examined in this study (T-RP (3.93 ± 3.97 mg/Kg), T-GP (7.09 ± 2.79 mg/Kg), T-TX (6.05 ± 1.92 mg/Kg), L-HH (4.68 ± 0.76 mg/Kg), L-SPLX (2.64 ± 1.63 mg/Kg). The concentration of detectable cadmium in T-RP park (0.16 ± 0.11 mg/Kg) was significantly higher than all the other five children's playgrounds studied L-WH (0.02 ± 0.01 ), T-GP (0.05 ± 0.04 mg/Kg), T-TX (0.02 ± 0.01 mg/Kg), L-HH (0.04 ± 0.01 mg/Kg), L-SPLX (0.09 ± 0.04 mg/Kg) (P<0.05). Conclusions The playgrounds contain detectable toxic metals that might pose health risks to children in the community. Though the lead levels are below the CDC-recommended lead soil concentration in urban areas, they still pose health risks to children in the environment when continuously exposed to the playground. The concentrations of Cu and Cr were not statistically different among the playgrounds. The detection of Pb and Cd highlights the potential health risks to children. Overall, this study shows that metal levels in playgrounds should be public information available to parents.
{"title":"B-277 Detectable Levels of Toxic Metals in Children's Playgrounds","authors":"J O Oyelakin-Ogunbileje, S T Oyelakin, R V Sadagopa","doi":"10.1093/clinchem/hvae106.634","DOIUrl":"https://doi.org/10.1093/clinchem/hvae106.634","url":null,"abstract":"Background Metal-contaminated soil poses significant health risks to kids because they are more sensitive to heavy metal exposure in the environment. Studies have shown that continuous exposure to metals can increase the risk of metal accumulation in blood and various body organs. This study determines the levels of some toxic metals in various playgrounds in our community. Methods We determined the levels of lead (Pb), chromium (Cr), cadmium (Cd), and copper (Cu) in six playgrounds (parks) (T-RP, T-GP, T-TX, L-HH, L-WH, L-SPLX) using graphite furnace atomic absorption spectrophotometry (GF-AAS) technique. Soil samples were collected at least one foot below the soil surface, and metal was extracted using ultra-pure nitric before analysis using GF-AAS. Data were analyzed using analysis of variance (ANOVA). Results The results showed significant detectable levels of the metals in all playgrounds evaluated in this study. L-WH Park in League City has the highest detectable levels of Pb (12.43 ± 46 mg/Kg, P&lt;0.05) compared to other children playgrounds examined in this study (T-RP (3.93 ± 3.97 mg/Kg), T-GP (7.09 ± 2.79 mg/Kg), T-TX (6.05 ± 1.92 mg/Kg), L-HH (4.68 ± 0.76 mg/Kg), L-SPLX (2.64 ± 1.63 mg/Kg). The concentration of detectable cadmium in T-RP park (0.16 ± 0.11 mg/Kg) was significantly higher than all the other five children's playgrounds studied L-WH (0.02 ± 0.01 ), T-GP (0.05 ± 0.04 mg/Kg), T-TX (0.02 ± 0.01 mg/Kg), L-HH (0.04 ± 0.01 mg/Kg), L-SPLX (0.09 ± 0.04 mg/Kg) (P&lt;0.05). Conclusions The playgrounds contain detectable toxic metals that might pose health risks to children in the community. Though the lead levels are below the CDC-recommended lead soil concentration in urban areas, they still pose health risks to children in the environment when continuously exposed to the playground. The concentrations of Cu and Cr were not statistically different among the playgrounds. The detection of Pb and Cd highlights the potential health risks to children. Overall, this study shows that metal levels in playgrounds should be public information available to parents.","PeriodicalId":10690,"journal":{"name":"Clinical chemistry","volume":"23 1","pages":""},"PeriodicalIF":9.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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