Estimating the intra- and inter-individual imprecision of manual pipetting

Clinical Chemistry and Laboratory Medicine (CCLM)

Šimundić²,

Plebani

2020

Self Cite

574

552

AbstractA novel zoonotic coronavirus outbreak is spreading all over the world. This pandemic disease has now been defined as novel coronavirus disease 2019 (COVID-19), and is sustained by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As the current gold standard for the etiological diagnosis of SARS-CoV-2 infection is (real time) reverse transcription polymerase chain reaction (rRT-PCR) on respiratory tract specimens, the diagnostic accuracy of this technique shall be considered a foremost prerequisite. Overall, potential RT-PCR vulnerabilities include general preanalytical issues such as identification problems, inadequate procedures for collection, handling, transport and storage of the swabs, collection of inappropriate or inadequate material (for quality or volume), presence of interfering substances, manual errors, as well as specific aspects such as sample contamination and testing patients receiving antiretroviral therapy. Some analytical problems may also contribute to jeopardize the diagnostic accuracy, including testing outside the diagnostic window, active viral recombination, use of inadequately validated assays, insufficient harmonization, instrument malfunctioning, along with other specific technical issues. Some practical indications can hence be identified for minimizing the risk of diagnostic errors, encompassing the improvement of diagnostic accuracy by combining clinical evidence with results of chest computed tomography (CT) and RT-PCR, interpretation of RT-PCR results according to epidemiologic, clinical and radiological factors, recollection and testing of upper (or lower) respiratory specimens in patients with negative RT-PCR test results and high suspicion or probability of infection, dissemination of clear instructions for specimen (especially swab) collection, management and storage, together with refinement of molecular target(s) and thorough compliance with analytical procedures, including quality assurance.

Section: Preanalytical Errorsmentioning

confidence: 99%

Potential preanalytical and analytical vulnerabilities in the laboratory diagnosis of coronavirus disease 2019 (COVID-19)

Clinical Chemistry and Laboratory Medicine (CCLM)

Šimundić²,

Plebani

2020

Self Cite

574

552

“…Although microplate ELISAs are very sensitive to Ddimer and have long been considered the reference method [1][2][3], they are manual, require technical skills, are time-consuming (i.e. around 2-4 h), and are plagued by a high degree of analytical imprecision [2,83].…”

Section: Analytical Variables D-dimer Assaysmentioning

confidence: 99%

D-dimer: Preanalytical, analytical, postanalytical variables, and clinical applications

Favresse

Critical Reviews in Clinical Laboratory Sciences

Roy

et al. 2018

Self Cite

145

103

D-dimer is a soluble fibrin degradation product deriving from the plasmin-mediated degradation of cross-linked fibrin. D-dimer can hence be considered a biomarker of activation of coagulation and fibrinolysis, and it is routinely used for ruling out venous thromboembolism (VTE). D-dimer is increasingly used to assess the risk of VTE recurrence and to help define the optimal duration of anticoagulation treatment in patients with VTE, for diagnosing disseminated intravascular coagulation, and for screening medical patients at increased risk of VTE. This review is aimed at (1) revising the definition of D-dimer; (2) discussing preanalytical variables affecting the measurement of D-dimer; (3) reviewing and comparing assay performance and some postanalytical variables (e.g. different units and age-adjusted cutoffs); and (4) discussing the use of D-dimer measurement across different clinical settings.

“…We read with interest articles written by Kitchen The innovative technology of the cobas t 711 analyzer provides some advances over existing coagulation instrumentation, such as availability of lyophilized reagents in barcoded cassettes, which can be automatically resuspended by the analyzer onboard, and may hence be seen a step forward for reducing the inherent imprecision of manual resuspension. 3 This may be especially beneficial in stat clinical laboratories, for shortening the turnaround time (TAT) and improving laboratory efficiency by decreasing manual activities. 4 The availability of rapid and accurate D-dimer (DD) assays is essential for timely management of patients with many thrombotic disorders, especially for ruling out venous thromboembolism (VTE) and disseminated intravascular coagulation (DIC).…”

Section: Analytical Performance Of the New D-dimer And Antithrombin Amentioning

confidence: 99%

Analytical performance of the new D‐dimer and antithrombin assay on Roche cobas t 711 analyzer

Salvagno

Gelati

et al. 2018

Int J Lab Hematology

Self Cite

while it was 0.91 (95% CI, 0.84-0.99; P < 0.001) for samples with DD values <1000 ng/L and 0.94 (95% CI, 0.88-1.00; P < 0.001) for those with DD values ≥1000 ng/L, respectively. Using the cutoff value provided by IL (230 ng/mL fibrinogen equivalent units; FEU), the best analytical cutoff of cobas t 711 DD was 470 ng/L (0.91 sensitivity and 0.91 specificity, respectively).The new generation of coagulation analyzers is increasingly designed to meet most of the essential needs of modern clinical laboratories, 9 thus including fully automated functioning, cap piercing, and large test menus (including a vast array of clotting, chromogenic, and immunoturbidimetric assays). Overall, the analytical performance of cobas t 711 analyzer was found to be optimal for routine use. The imprecision data are aligned with, or even better than, those of other commercially available coagulation analyzers, reported in previous studies. 5 Linearity of cobas t 711 analyzer was also excellent over the clinically relevant range of values of both DD and AT, with correlation coefficients of 0.999. Method comparison studies also showed that DD and AT values obtained with cobas t 711 analyzer are substantially aligned to those obtained on paired samples with ACL TOP (Figure 1), displaying correlation coefficients always >0.96, albeit the DD unit reported differed slightly, thus further supporting the continued need for major standardization of this assay . 10In conclusion, the results of this analytical evaluation of cobas t 711 analyzer DD and AT reagents expand previous reports on this instrument, showing that these tests display excellent performance for both routine and stat laboratories. ACK N OWLED G EM ENTSThe manufacturer provided in-kind support in the form of equipment and consumables for the evaluation of the equipment. The manufacturer had no role in directing the study or influencing the study outcomes.