Clinical chemistry and laboratory medicine最新文献

Objectives: In the light of a rapidly increasing use of POCT blood gas testing, where tests and interpretation are performed by non-laboratory personnel, the objective was to investigate the knowledge among personnel in the Nordic countries using blood gas analyzers with focus on the interference from hemolysis.

Methods: Information was obtained from a self-developed, pre-tested online questionnaire. The questions covered demographic information about the respondents and specific questions on handling of and knowledge about blood gas analyses and the impact of hemolysis. The questionnaire was distributed by e-mail to relevant colleagues on behalf of the Nordic preanalytical scientific working group under the Nordic Federation of Clinical Chemistry.

Results: A total of 117 respondents completed the questionnaire. 62.7 % respondents both used the analyzer and interpreted the results. 59.6 % respondents did not know to which degree the blood gas analyzer can identify hemolysis. 4.4 % answered that all levels or high levels of hemolysis can be detected. 3.9 % considered the result valid despite hemolysis if it is released from the instrument. 73.7 % of all respondents knew that hemolysis alters potassium measurements, while knowledge about the effect on PaO₂ and bicarbonate measurements were more divergent.

Conclusions: The knowledge about blood gas analyzers with focus on the interference from hemolysis is sparse among non-laboratory personnel using the blood gas analyzers. This emphasizes the need for better education and competence management, which perhaps is even more important for these analyses than for other point-of-care tests.

Objectives: Automated immunoassays for 1,25-dihydroxyvitamin D (1,25(OH)₂D) have increased the use of serum measurements in clinical and research settings, but disagreement with LC-MS/MS methods remains an issue.

Methods: In this study, we examined this problem using samples obtained from healthy young adults, n=80, mean age 21.7 (18-32) years, and a large cohort of paediatric samples, n=422, mean age 7.3 (0-17) years. We compared serum concentrations of 1,25(OH)₂D3/D2 produced by the DiaSorin LIAISON^® XL immunoassay against an LC-MS/MS method with immunoaffinity enrichment and DAPTAD derivation.

Results: Both assays showed intra/inter-assay imprecision of ≤9.4 % across their respective assay range. DEQAS between April 2020 to Jan 2024 (n=80) showed mean bias (SD, 95 %CI) for DiaSorin -0.6 % (6.2, -12.8 to 11.6) and LC-MS/MS of +1.3 % (7.4, -13.3 to 15.8) against their respective method group means. Comparison of measurements in the adult samples showed a strong correlation (r²=0.9331) and concordance (CCC=0.959) between the two methods. LC-MS/MS values were lower than DiaSorin by an overall mean (±SD, 95 %CI) of -1.6 (±14.3, -29.6 to 26.5) pmol/L with an increased negative bias at higher concentrations. In the paediatric samples, weaker correlation (r²=0.6536) and concordance (CCC=0.782) were observed, with greater bias mean (±SD, 95 %CI) of -9.8 (±23.4, -55.7 to 35.9) pmol/L. The variability in the paediatric samples was not associated with concentration or participant age. There was an increase in the correlation and concordance when 1,25(OH)₂D2 was included in the analysis.

Conclusions: It is likely that the metabolites of vitamin D present in the paediatric population contributed to the measurement of 1,25(OH)₂D. The inconsistent agreement highlights the need for better assay harmonisation and paediatric reference intervals using LC-MS/MS method.

Objectives: Diurnal variation of plasma glucose levels may contribute to diagnostic uncertainty. The permissible time interval, pT(t), was proposed as a time-dependent characteristic to specify the time within which glucose levels from two consecutive samples are not biased by the time of blood collection. A major obstacle is the lack of population-specific data that reflect the diurnal course of a measurand. To overcome this issue, an approach was developed to detect and assess diurnal courses from big data.

Methods: A quantile regression model, QRM, was developed comprising two-component cosinor analyses and time, age, and sex as predictors. Population-specific canonical diurnal courses were generated employing more than two million plasma glucose values from four different hospital laboratory sites. Permissible measurement uncertainties, pU, were also estimated by a population-specific approach to render Chronomaps that depict pT(t) for any timestamp of interest.

Results: The QRM revealed significant diurnal rhythmometrics with good agreement between the four sites. A minimum pT(t) of 3 h exists for median glucose levels that is independent from sampling times. However, amplitudes increase in a concentration-dependent manner and shorten pT(t) down to 72 min. Assessment of pT(t) in 793,048 paired follow-up samples from 99,453 patients revealed a portion of 24.2 % sample pairs that violated the indicated pT(t).

Conclusions: QRM is suitable to render Chronomaps from population specific time courses and suggest that more stringent sampling schedules are required, especially in patients with elevated glucose levels.

Objectives: Emergency department (ED) crowding is a widespread problem that positions patients at risk. The desire to improve the ED throughput requires novel approaches. Point-of-care testing (POCT) has emerged as useful technology that could contribute to create more efficient patient flow and better timeliness in the ED. The main objective of our study is to demonstrate, in a multicenter study, that POCT benefits care timeliness in the ED.

Methods: We conducted a multicenter and cluster randomized study. A total of 3,200 patients. We randomly assigned patients to a POCT group or Central Laboratory Group. The primary outcome was the ED time to clinical decision. The secondary outcome included the length of stay and the laboratory turnaround time. Readmission within the seven after discharge was also calculated.

Results: The primary finding of this study is a strategy based on POCT that aims to significantly improve care timeliness in the ED. We found significant reductions in all outcomes regardless of presentation reason, patient disposition or hospital type. Time to clinical decision decreased by 75.2 min (205-129.8), length of stay by 77.5 min (273.1-195.6) and laboratory turnaround time by 56.2 min (82.2-26) in the POCT group. No increase in readmission was found.

Conclusions: Our strategy represents a good approach to optimize timeliness in the ED. It should be seen as a starting point for further operational research focusing on POCT for improving throughput and reducing crowding in the ED.

Objectives: Serum total bile acid (TBA) levels are frequently assessed in clinical routine for the early detection of hepatobiliary dysfunction. However, the comparability of current 5th-generation TBA cycle assays based on 3α-hydroxysteroid dehydrogenase (3α-HSD) and their ability to quantify individual bile acids has not been systematically addressed.

Methods: Patient serum samples (n=60) across the diagnostically relevant TBA range (1-200 μmol/L) were analyzed using five TBA routine assays from Abbott, DiaSys, Diazyme, Beijing Strong (BSBE) and Randox on the same analyzer (BioMajesty^® JCA-BM6010/C). The assays were compared using Passing-Bablok regression and the recovery of 11 individual BAs was evaluated against RP-HPLC-MS/MS as non-enzymatic reference method.

Results: Despite excellent correlation (Spearman r ≥0.99), the assays showed proportional differences (slope) ranging from 0.99 (BSBE/Randox) to 1.24 (Abbott/DiaSys). The assays showed considerable deviation in the recovery of competitor's calibrators and controls, and large heterogeneity in the recovery of individual BAs, with mean deviations from reference value between 13 % (DiaSys) and 42 % (Abbott). CA and TCA were measured most accurately and consistently, whereas GCA, CDCA, DCA, UDCA, and conjugates were over- or undermeasured to varying degrees.

Conclusions: The linear relationship and constant proportional bias between all five routine assays enable the harmonization of TBA measurements up to 60 μmol/L. However, for patient samples with high TBA levels and disease-specific overrepresentation of individual BAs, harmonization will require: i) optimized reaction conditions to equalize substrate specificity, and ii) calibration to a common, commutable reference material with well-defined BA composition instead of internal standards spiked with different BAs.

Objectives: This study aimed to determine the clinical significance of Krebs von den Lungen-6 (KL-6), surfactant proteins A (SP-A) and D (SP-D) in the evaluation and management of interstitial lung disease (ILD).

Methods: Serum KL-6, SP-A, SP-D levels were measured in 122 unique consecutive patients referred for connective tissue disease (CTD) associated ILD (CTD-ILD) autoantibodies and 120 "healthy" controls. Patients' charts were retrospectively reviewed and categorized as ILD and non-ILD or CTD-ILD and other ILD. All biomarkers were evaluated for diagnosis and moderate vs. severe ILD based on high-resolution computed tomography (HRCT).

Results: ILD was diagnosed in 52 % (n=64) and non-ILD in 48 % (n=58). ILD patients were categorized as other ILD (61 %, n=39) or CTD-ILD (39 %, n=25). Patients with ILD had significantly elevated levels of SP-A (p<0.02), KL-6 or SP-D (both p<0.0001) when compared to those with non-ILD. The mean levels of all biomarkers were significantly elevated levels in the ILD compared to non-ILD group (p<0.0001). No significant difference in biomarker levels between CTD-ILD and other ILD groups (p≥0.900). Biomarkers had comparable specificities (89-93 %) however; sensitivities were variable at 75 , 77 and 17 % for KL-6, SP-D and SP-A, respectively. Combination of KL-6 and SP-D yielded comparable diagnostic accuracy to all biomarkers with median levels significantly higher in patients with severe vs. mild disease.

Conclusions: KL-6 and SP-D levels are elevated in ILD and therefore contribute to the diagnosis and risk stratification for patient management.