Analytical evaluation of Diazyme procalcitonin (PCT) latex-enhanced immunoturbidimetric assay on Beckman Coulter AU5800

Abstract Background: This study was aimed to evaluate the analytical performance of the novel Diazyme procalcitonin (PCT) immunoturbidimetric assay on Beckman Coulter AU5800. Methods: Diazyme PCT is a latex-enhanced immunoturbidimetric assay, developed for use on laboratory instrumentations with capability of reading absorbance at 600 nm. This analytical evaluation included the assessment of limit of blank (LOB), limit of detection (LOD), functional sensitivity, imprecision, linearity, carryover, and method comparison between Diazyme PCT and Kryptor PCT on 129 routine serum inpatient samples. Results: The LOB, LOD, and functional sensitivity of Diazyme PCT were 0.16, 0.26, and 0.28 ng/mL, respectively. The intra-and inter-assay imprecision of Diazyme PCT was between 2.9% and 7.8%. The linearity was excellent in the range of PCT values between 0.16 and 56 ng/mL, and the carryover was negligible (0.02%). A highly significant agreement was found between Kryptor PCT and Diazyme PCT in a range of concentrations between 0.16 and 111 ng/mL (Diazyme PCT = 1.10 × Kryptor PCT -0.89; r = 0.960; p < 0.001). The mean bias was 0.48 ng/mL (95% CI, -0.58 to 1.54 ng/mL). The strength of agreement between Kryptor PCT and Diazyme PCT was between 85% and 96% at 0.50, 2.0, and 10 ng/mL cutoffs

Evaluation of 99th percentile and reference change values of a high-sensitivity cTnI method: A multicenter study

Abstract Background The Italian Society of Clinical Biochemistry (SIBioC) and the Italian Section of the European Ligand Assay Society (ELAS) have recently promoted a multicenter study (Italian hs-cTnI Study) with the aim to accurately evaluate analytical performances and reference values of the most popular cTnI methods commercially available in Italy. The aim of this article is to report the results of the Italian hs-cTnI Study concerning the evaluation of the 99th percentile URL and reference change (RCV) values around the 99th URL of the Access cTnI method. Materials and methods Heparinized plasma samples were collected from 1306 healthy adult volunteers by 8 Italian clinical centers. Every center collected from 50 to 150 plasma samples from healthy adult subjects. All volunteers denied the presence of chronic or acute diseases and had normal values of routine laboratory tests (including creatinine, electrolytes, glucose and blood counts). An older cohort of 457 adult subjects (mean age 63.0 years; SD 8.1 years, minimum 47 years, maximum 86 years) underwent also ECG and cardiac imaging analysis in order to exclude the presence of asymptomatic cardiac disease. Results and conclusions The results of the present study confirm that the Access hsTnI method using the DxI platform satisfies the two criteria required by international guidelines for high-sensitivity methods for cTn assay. Furthermore, the results of this study confirm that the calculation of the 99th percentile URL values are greatly affected not only by age and sex of the reference population, but also by the statistical approach used for calculation of cTnI distribution parameters

Analytical assessment of the novel Maglumi squamous cell carcinoma antigen (SCCA) immunoluminometric assay.

Background: The demand for routine measurement of squamous cell carcinoma antigen (SCCA) is rapidly increasing in clinical laboratories, due to the central role that this biomarker plays in staging and monitoring patients with various forms of squamous cell carcinomas (SCCs).Methods: The present analytical evaluation of Maglumi SCCA was aimed to assess the imprecision, linearity and comparability against a widely used technique.Results: The intra- and inter-assay imprecision was comprised between 2.6-4.2% and between 5.0-7.3%, respectively. The linearity of the test was excellent in the range of SCC values comprised between 1.0 and 18.0 ng/mL (r=0.998; P<0.001). A highly significant correlation was observed between Maglumi SCCA and BRAHMS Kryptor SCC in the range of values comprised between 0.44 and 15.18 ng/mL (r=0.960; P<0.001). The mean bias was 0.79 ng/mL (95% CI, 0.61-0.97) and the diagnostic agreement at the respective diagnostic cut-offs was 95%.Conclusions: The results of this study confirm that Maglumi SCCA may be regarded as a suitable alternative to Kryptor SCC for routine and fully-automated assessment of SCCA in clinical laboratories

Comparison of the novel Maglumi ferritin immunoluminometric assay with Beckman Coulter DxI 800 ferritin

Background: The demand for routine measurement of ferritin is constantly increasing in clinical laboratories due to the clinical value of this biomarker for diagnosing anemia. Therefore, this study was aimed to compare the newly commercialized Maglumi ferritin immunoluminometric assay with a validated commercial and fully automated technique.Methods: The comparison study included 95 consecutive inpatient serum samples referred to the local laboratory for routine ferritin measurement. Serum was separated, divided in two paired aliquots and immediately analyzed with both Beckman Coulter DxI 800 and Maglumi 2000. Correlation was assessed with Deming fit and Spearman\u2019s correlation, the mean bias was estimated with Bland-Altman plot. The concordance between methods was calculated as percentage agreement and \u3ba coefficient.Results: An excellent correlation was observed between Maglumi and DxI (r=0.997). The mean bias was 34 ng/mL and the strength of agreement between values obtained with Maglumi and DxI was 98% and 100% at the lower and upper limits of the reference range. The agreement was also 98% for diagnosing iron deficiency and 94% for diagnosing iron overload.Conclusions: Maglumi immunoassay may be regarded as a suitable alternative for routine and fully-automated assessment of ferritin in clinical laboratories

Clinical, organizational and economic analysis of high-sensitivity cardiac troponin testing in the emergency department

Background: Although high-sensitivity (HS) cardiac troponin I (cTnI) immunoassays have enhanced efficiency for early rule-out of acute coronary syndrome (ACS) compared to contemporary-sensitive (CS) techniques, no reliable information has been published in support of their cost-effectiveness. Therefore, this study was designed to evaluate the clinical, economic and organizational advantages of using a HS-cTnI immunoassay compared to a conventional CS-cTnI technique for early management of patients admitted to the emergency department (ED) with suspected ACS. Methods: The study population consisted of 288 consecutive patients admitted to the ED for suspected ACS over a 3-month period. cTnI was measured with both HS-cTnI and CS-cTnI immunoassays. The clinical, economic and organizational impact was analyzed according to patient management based upon results of either method. Results: ACS could be rapidly ruled out in a larger number of patients using HS-cTnI than CS-cTnI (68.7% versus 52.4%). The overall stay in the ED for ACS diagnostics was nearly 20% shorter using HS-cTnI than using CS-cTnI (1.9\ub11.4 versus 2.4\ub11.5 hour/patient; P<0.001). The mean cost for patient management in the ED was 128\ub192\u20ac using HS-cTnI compared to 160\ub199\u20ac with CS-cTnI (\u201320%; P<0.001) Conclusions: The results of this study suggest that replacing CS-cTnI with HS-cTnI immunoassays may be effective for enhancing the efficiency of early rule-out of ACS, but also generates a favourable organizational and economic impact in the ED

Heart-type fatty acid-binding protein after ultramarathon running and relationship with high-sensitivity troponin I

Heart-type fatty acid-binding protein after ultramarathon running and relationship with high-sensitivity troponin I

Red blood cell distribution width and erythrocyte parameters in patients with brain injury after mild head trauma

This prospective study was planned to assess whether red blood cell (RBC) parameters may be useful in diagnostics of patients with brain injury after mild head trauma. The RBC count, hemoglobin, hematocrit, RBC distribution width (RDW) and mean corpuscular volume were assessed in all consecutive patients admitted to the emergency department over 3 months with isolate, mild head trauma and Glasgow coma scale between 14-15, and seen within 3 h from trauma. The final study population consisted of 54 patients (21 women and 33 men; median age=48 years), of whom, 13 (24%) with positive computed tomography (CT). No significant difference was found for age (P=0.45) and gender (P=0.21) distribution between CT positive and negative patients. No significant difference was observed for the median concentration of all the RBC parameters tested, and the preva- lence of anemia (P=0.37) and anysocytosis (P=0.40) did not differ significantly between patients with positive and negative CT. Red blood cell distribution width assessment upon patient admission did not provide a significant contribution to final diagnosis of mild head injury in receiver operating characteristic curve analysis [area under the curve (AUC) 0.51; P=0.44]. We conclude that assessment of RDW does not provide useful clinical information for diagnosing brain injury after mild head trauma

Analytical assessment of the novel homocysteine liquid enzymatic assay on Beckman Coulter AU5800

Analytical assessment of the novel homocysteine liquid enzymatic assay on Beckman Coulter AU5800

Comparison of Procalcitonin Assays on KRYPTOR and LIAISON® XL Analyzers

Our laboratory performs procalcitonin (PCT) assays on a Brahms KRYPTOR analyzer with the Brahms PCT sensitive Kryptor kit. In this study, we wanted to compare the assays obtained in this way with the ones performed on the LIAISON&reg; XL. From January to May 2017, 171 samples were analyzed, of which 65 from female patients (age: 22&ndash;98 years) and 106 from male patients (age: 16&ndash;97 years). The PCT determination was performed using the LIAISON&reg; XL and KRYPTOR analyzers, by chemiluminescence (Chemiluminescence immunoassay&mdash;CLIA) (LIAISON&reg; BRAHMS PCT&reg; II GEN) and immunofluorescence (Brahms PCT sensitive Kryptor) assay, respectively. For the LIAISON&reg; BRAHMS PCT&reg; II GEN, 52% of the results were placed between 0.0 and 0.5 ng/mL, 18% between 0.5 and 2.0 ng/mL, and 30% between 2.0 and 100 ng/mL; the mean was 4.09 ng/mL, the median 0.456 ng/mL, the maximum value 97.2 ng/mL, and the minimum value 0.02 ng/mL. For the Brahms PCT sensitive Kryptor, 55% of the results were positioned between 0.0 and 0.5 ng/mL, 21% between 0.5 and 2.0 ng/mL, and 24% between 2.0 and 100 ng/mL; the mean was 3.72 ng/mL, the median 0.39 ng/mL, the maximum value 103 ng/mL, and the minimum value 0.01 ng/mL. The mean of the results obtained with the two methods showed no significant differences (3.717 for Kryptor and 4.094 for LIAISON&reg;). PCT assay with Brahms reagents, both on the Kryptor and LIAISON&reg;XL platforms, offers excellent performance in terms of sensitivity and specificity

Wczesna kinetyka stężenia sercowego białka wiążącego kwasy tłuszczowe u chorych poddanych echokardiografii obciążeniowej z dipirydamolem oraz zależności ze stężeniem troponin oznaczonych metodą wysokoczułą

Background: The assessment of cardiospecific troponins is the main stay for diagnosing myocardial injury, although their diagnostic sensitivity remains suboptimal at patient admission to the emergency department (ED), thus paving the way for translational research to identify early and complementary biomarkers which may help improve the diagnostic sensitivity of high-sensitivity troponin immunoassays at patient presentation to the ED.Aim: To investigate whether heart-type fatty acid binding protein (H-FABP) provides distinctive and/or adjunctive information over high-sensitivity troponin I (HS-TnI) in ED patients undergoing dipyridamole stress testing.Methods: Thirty consecutive ED patients with chest pain but no myocardial ischaemia were challenged with dipyridamole-atropine and followed by echocardiography. Blood samples for assessing H-FABP and HS-TnI were collected before the dipyridamole challenge, immediately after, and 6 h afterwards.Results: The concentration of HS-TnI in the whole cohort of patients did not vary significantly throughout the study period, whereas H-FABP significantly increased after the test (4.2 ng/mL, p = 0.003), but not 6 h afterwards (3.8 ng/mL, p = 0.372) compared to baseline (4.0 ng/mL). The kinetics was similar in patients with positive or negative results of stress testing. The frequency of biomarker increase after the test was greater for H-FABP than for HS-TnI immediately after the pharmacological challenge (77% vs. 53%), but was lower 6 h afterwards (30% vs. 63%). The number of patients with values exceeding the diagnostic threshold of both biomarkers remained constant throughout the study period.Conclusions: These results suggest that dipyridamole stress echocardiography does not trigger substantial myocardial injury. We have also shown that release of H-FABP from stressed myocardium occurs without progression towards irreversible necrosis, and is more precious than that of TnI.Wstęp: Podstawową metodą w diagnostyce uszkodzenia mięśnia sercowego jest oznaczenie swoistych troponin sercowych, jednak czułość tego badania nie jest wystarczająca w przypadku pacjentów zgłaszających się na oddział ratunkowy. Dlatego też poszukuje się wczesnych biomarkerów zapewniających dodatkowe informacje, które umożliwiłyby zwiększenie czułości diagnostycznej w stosunku do oznaczenia troponin metodą wysokoczułą u pacjentów zgłaszających się na oddział ratunkowy.Cel: Celem pracy było zbadanie, czy sercowe białko wiążące kwasy tłuszczowe (H-FABP) dostarcza odmiennych i/lub dodatkowych informacji w stosunku do oznaczenia stężenia troponiny I metodą wysokoczułą (HS-TnI) u chorych, u których przeprowadzono próbę dipirydamolową na oddziale ratunkowym.Metody: U 30 kolejnych pacjentów, którzy zgłosili się na oddział ratunkowy z bólem w klatce piersiowej, jednak bez cech niedokrwienia mięśnia sercowego, przeprowadzono echokardiograficzną próbę obciążenia dipirydamolem–atropiną. Próbki krwi w celu oznaczenia H-FABP i HS-TnI pobrano przed przeprowadzeniem próby dipirydamolowej, bezpośrednio po niejoraz po 6 godzinach.Wyniki: Stężenia HS-TnI w całej grupie chorych nie różniły się znamiennie w okresie badania, natomiast H-FABP zwiększyło się istotnie w stosunku do wartości wyjściowych (4,0 ng/ml) bezpośrednio po próbie dipirydamolowej (4,2 ng/ml; p = 0,003), ale nie 6 godzin później (3,8 ng/ml; p = 0,372). Parametry kinetyczne były podobne u pacjentów z dodatnim i ujemnym wynikiem próby wysiłkowej. Bezpośrednio po próbie obciążeniowej częściej obserwowano zwiększenie stężenia H-FABP niż HS-Tn-1 (77% vs. 53%), natomiast po 6 godzinach te proporcje się odwróciły (30% vs. 63%). Liczba chorych, u których wartości obu markerów przekraczały próg diagnostyczny, pozostawała niezmienna przez cały okres badania.Wnioski: Wyniki sugerują, że echokardiograficzna próba obciążeniowa z dipirydamolem nie powoduje istotnego uszkodzenia mięśnia sercowego. Ponadto wykazano, że uwalnianie H-FABP z mięśnia sercowego w warunkach obciążenia nie wiąże się z progresją do nieodwracalnej martwicy i że ma większą wartość diagnostyczną niż oznaczenie TnI