Clinical chemistry and laboratory medicine最新文献

Objectives: Until now, the external quality assessment (EQA) of glucose point-of-care testing (POCT) has lacked a high quality, suitable and commutable control material to assess measurement accuracy. Here we present a concept for determining the accuracy of glucose measurements, which uses human whole blood and does not require stabilising agents.

Methods: This new generation of quality control samples uses a bead that contains a specific amount of glucose. The bead is then dissolved in a whole blood matrix by the EQA participant immediately before the POCT. We analysed its suitability as an EQA material with respect to its reproducibility, homogeneity and stability, and applied it in an EQA pilot study. The glucose target value was determined using the reference measurement procedure and served as an evaluation criterion for the accuracy of the EQA survey results.

Results: The homogeneity and stability of the new control material fulfilled the quality requirements of ISO 17043. Based on the reference measurement value for glucose, the results of the pilot EQA scheme showed a pass rate of 84.6 % for the participating POCT devices. The acceptance limit was a 15 % permitted deviation from the target value according to Rili-BAEK. All of the device collectives deviated from the target value by 0-4.4 % with the exception of one device type, which deviated by 21 %.

Conclusions: The new concept offers, for the first-time, whole blood-based trueness controls for glucose POCT analysis for external quality assurance. The concept does not require the addition of any stabilising reagent and is easy to use.

Objectives: With the increasing demand and application of lymphocyte subsets detection in clinical laboratories, different single-platform flow cytometer (FCM) systems have been developed. There is an urgent need to establish the reference intervals (RIs) for different single-platform FCMs and transferring them from one FCM system to another provides a much more feasible and convenient approach. This study aimed to explore the transferability of RIs for lymphocyte subsets across different flow cytometry platforms.

Methods: We first conducted the pairwise method comparison across four FCM platforms, including NovoCyte, BriCyteE6, DxFLEX, and FACSCantoII systems. Next, the transferability of RIs of lymphocyte subsets was evaluated. Furthermore, we conducted the RIs transference based on the FACSCantoII system, BriCyteE6 system and DxFLEX system, except for NK cells. The transferred RIs were further verified by calculating the bias (CV) between the established ones.

Results: The results of lymphocyte subsets detection based on the NovoCyte, BriCyteE6, DxFLEX, and FACSCantoII systems were comparable and it was feasible to transfer the RIs of lymphocyte subsets detected by the four FCM systems. The RIs of lymphocyte subsets detection using FACSCantoII, DxFLEX, and BriCyteE6 systems were established. Upon transferring the RIs of lymphocyte subsets from the FACSCantoII system to the BriCyteE6 system, and DxFLEX system except for NK cells, the CV between the transferred RIs and the established ones was below 20 % for all parameters.

Conclusions: The present study illustrated that the RIs of lymphocyte subsets could be transferred across different flow cytometry systems except for NK cells with different definition strategies.

Objectives: Lab testing is a high-volume activity that is often overused, leading to wasted resources and inappropriate care. Improving test ordering practices in tertiary care involves deciding where to focus scarce intervention resources, but clear guidance on how to optimize these resources is lacking. We aimed to explore context-sensitive factors and processes that inform individual decisions about laboratory stewardship interventions by speaking to key interest holders in this area.

Methods: We conducted semi-structured interviews with test-ordering intervention development experts and authors of test-ordering guidance documents to explore five broad topics: 1) processes used to prioritize tests for intervention; 2) factors considered when deciding which tests to target; 3) measurement of these factors; 4) interventions selected; 5) suggestions for a framework to support these decisions. Transcripts were double coded using directed-content and thematic analysis.

Results: We interviewed 14 intervention development experts. Experts noted they frequently consider test volume, test value, and patient care when deciding on a test to target. Experts indicated that quantifying many relevant factors was challenging. Processes to support these decisions often involved examining local data, obtaining buy-in, and relying on an existing guideline. Suggestions for building a framework emphasized the importance of collaboration, consideration of context and resources, and starting with "easy wins" to gain support and experience.

Conclusions: Our study provides insight into the factors and processes experts consider when deciding which tests to target for intervention and can inform the development of a framework to guide the selection of tests for intervention and guideline development.

Objectives: Atypical cells (Atyp.C), as a new parameter determined by an automated urine analyzer, can be suspected of being malignant tumor cells. We evaluated the extent to which the Atyp.C can predict the existence of malignant tumor cells.

Methods: A total of 3,315 patients (1,751 in the training cohort and 1,564 in the testing cohort) were recruited and divided into five groups, namely, primary bladder cancer (BCa), recurrent BCa, post-treatment monitoring of BCa, other urological tumors, and controls. Urine Atyp. C, bacteria, white blood cell, and red blood cell were measured by a Sysmex UF-5000 analyzer. We compared the Atyp.C values across the different groups, sexes, and tumor stages. The diagnostic performance of Atyp.C alone and in combination with other parameters for detecting BCa was evaluated using receiver operating characteristic (ROC) curve analysis.

Results: The Atyp.C value of the primary BCa group was significantly higher than that in the other groups, except recurrent BCa group. The Atyp.C value was closely related to tumor staging. Atyp.C combined with bacteria had the highest diagnostic performance for primary BCa [training cohort AUC: 0.781 (95 % CI: 0.761-0.801); testing cohort AUC: 0.826 (95 % CI: 0.806-0.845)]. The AUC value of diagnosed recurrent BCa by Atyp.C plus bacteria for the training cohort was 0.784 (95 % CI: 0.762-0.804).

Conclusions: Atyp.C was high in primary BCa patients and the combination of bacteria and Atyp.C showed high predictive value for primary BCa, suggesting that Atyp.C may be a useful objective indicator for the early detection of BCa.

Objectives: Fecal immunochemical tests (FIT) for hemoglobin are currently considered the screening investigation of choice for colorectal cancer and are worldwide recommended. Similarly, fecal calprotectin is a widely used test for monitoring intestinal inflammation. The pre-analytical issues regarding stool samples have hardly been dealt with and are difficult to solve. Currently, there are no reference analytes available which allow to correct test results for the variable water content of the stool sample. Studies on preanalytics of stool samples have generally focused on sample preparation and sample storage, but generally have paid little attention to the variability in sample hydration and sample composition.

Methods: Stercobilin is a stable heme metabolite which is abundant in stool. Stercobilin concentration can be simply assayed in stool extracts using colorimetry (determination of the I index). Serum indices (H, I and L) and bilirubin concentration of fecal extracts were determined on a Atellica Platform (Siemens).

Results: The inter-individual variation of stercobilin was found to be high. Assaying stercobilin allows to correct for stool sample dilution. The median value of the I-index was used as a reference for correcting the data. Correcting fecal blood results for sample dilution resulted in a significant increase in positive tests (from 9.3 to 11.7 %). For calprotectin, correction resulted in 3.1 % extra positive results and 7.7 % negative results.

Conclusions: Except in the case of obstructive jaundice, this correction can be applied. Correcting test results of common fecal analytes like FIT and calprotectin may result in a better tailored test interpretation.

The biotechnology company Grail developed a non-invasive blood test (Galleri test) which is claimed to detect 50 types of cancer at early and potentially curable stages. The initially promising results from prospective studies, and the anticipated financial success of Grail led the sequencing giant Illumina to purchase Grail for $8 billion (2021). Following this event, Grail collaborated with the UK National Health System to further clarify the test's capability, in a 3-year prospective trial, along with the standard of care. The UK-NHS announced that the trial will provide a clearer understanding of the efficacy of the Galleri test within the NHS framework. If the test does not perform as expected, valuable insights will still be gained to guide future research aimed at enhancing cancer screening. We previously expressed concerns about the sensitivity and specificity of the Galleri test. In this opinion paper, we revisit the hyped technology, and we provide new suggestions on the use of this test.