Clinical biochemistry最新文献

Background: Reagent stability is a significant determinant of analytical reliability in clinical laboratories. Post-expiry reagent use is often discouraged due to the potential risk of systematic bias; however, empirical data supporting or refuting such restrictions are limited.

Methods: This study evaluated the post-expiry performance of free T3 (FT3) and free T4 (FT4) immunoassays on the Abbott Architect i1000SR analyzer using an integrated framework combining three complementary approaches: (i) a simulation-optimized moving average (MA) model based on real patient data (ii) Westgard Sigma rules quality control, and (iii) Clinical and Laboratory Standards Institute EP25-A drift analysis. The MA was optimised via Monte Carlo simulations using a step-shift bias model, which defined the optimal window size (N) for 90% detection power and 0% false rejection rate. Stability was then assessed across three reagent lots per analyte, spanning both pre- and post-expiration phases.

Results: Westgard rules provided the earliest analytical alerts, while EP25 confirmed sustained drift relative to allowable total error. The MA detected progressive instability, showing strong concordance with EP25 after lag correction (N × cadence). FT4 indicated extended stability of up to 19 months post-expiry, while FT3 showed limited stability (<4 months). These differences reflected distinct assay robustness and kinetics.

Conclusions: The combination of Westgard sigma rules, EP25, and simulation-optimized MA provides a reproducible, data-driven framework for post-expiry reagent stability assessment. Optimizing MA with real patient data enhances detection performance, bridging theoretical quality-control design and routine laboratory application. This integrated approach enables laboratories to make scientifically justified, cost-effective decisions regarding reagent reuse beyond manufacturer expiry dates.

Seed amplification assays have shown promise in research for accurate diagnosis of synucleinopathies. In consideration of clinical implementation, gaps in the literature include that performance data are frequently determined using clinically unrelated controls (e.g., healthy controls or phenotypically unrelated conditions [UC]), and a lack of emphasis on methodological variability, including required replicates and positivity thresholds. A review and meta-analysis were performed to assess the methodological parameters and diagnostic performance of seed amplification assays for detecting synucleinopathies and, where necessary, cohorts were adjusted to be more representative of the populations in which the testing would be deployed in clinical practice. A search was conducted for α-synuclein seed amplification assay studies on Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, for matrices including cerebrospinal fluid (CSF), skin, and olfactory mucosa (OM). Assay methodological details were extracted, as were diagnostic performance data. For the latter, negative controls were divided into two distinct groups: disease mimics (DM) and UC. A total of 55 studies met the inclusion/exclusion criteria. Methodological parameters varied including the concentration, sequence and source of the assay substrate, as well as required assay replicates and determination of the positivity threshold. Median sensitivities and specificities relative to DM groups for CSF were 0.92 (95% confidence interval: 0.88-0.96) and 0.90 (0.89-0.96), for skin were 0.94 (0.79-1.0) and 0.86 (0.83-1.0), and for OM were 0.69 (0.33-1.0) and 0.94 (0.83-1.0), respectively. Although diagnostic performance was slightly reduced when adjusting for clinically relevant populations, it remained encouragingly high. Towards broader clinical implementation, valuable research directions include further streamlining of analytical workflows, and characterizing diagnostic performance by stage of disease and co-pathologies.

This article reflects on the relationship between Planetary Health and healthcare workers in 2025. As clinical chemistry specialists working within the healthcare system, attention to the health of the patients who utilize our portion of the healthcare system now extends beyond provision of information. How we provide that information, how often we provide this information, and how extensive the information is that we do provide impacts Planetary Health - the major determinant of health for our patients born this year and thereafter. We summarize the importance of looking at this broader view of health as lab specialists have agency in effecting how clinical labs operate in the remainder of this century. Our position is that this agency should be in alliance with Planetary Health for the benefit of our patient's health in the next generations. We recognize the patient born today, a 50 year old in 2075, as a Patient Advocate Virtual (PAV) who could symbolically be present in decision making in the clinical lab - and throughout the healthcare system - to remind us of the importance of caring for Planetary health tomorrow while we care for patients today.