Similar symptoms between viral and bacterial diseases often make diagnosis difficult. This study assessed the clinical performance of the newly cleared whole-blood Bacterial versus Viral Score assay in our pediatric cohort to the previously validated serum assay and emergency department physician diagnosis. This assay shows excellent agreement (R = 0.997) with the serum assay and has great diagnostic accuracy when compared to physician diagnosis.
This study aimed to create an in-house glucose quality control material for humans, addressing the challenge of obtaining high-cost commercially prepared quality control materials in developing countries.
An in-house quality control material for glucose was prepared using a pooled serum sample and analyzed using a fully automated chemistry analyzer following the ISO 80 guidelines. The mean, standard deviation (SD), and coefficient of variance were calculated from the first 30 days of measurement, and the variability was checked over eight months using SPSS software. The study used Pearson's correlation with a 95% confidence interval and a P-value less than 0.05, which was statistically significant.
The average mean ± SD of human serum glucose was 185.2 ± 8.4 mg/dL, indicating that the precision between each measurement was better. The prepared in-house quality control material was stable for approximately five months without any significant change in the serum glucose concentration (mg/dl) (p-value<0.05).
The study suggests that room-temperature, 2–8 °C, and −20 °C to −30 °C storage of human serum samples for glucose analysis is a viable option, with stable glucose concentrations for up to 30 days. Pooled serum is a cost-effective method for in-house quality control, especially in resource-limited laboratories.
Swabbing with ethanol to disinfect the skin before venipuncture does not bias measurements of blood ethanol, as previously suspected. International evidence-based theory may not always be successfully integrated into local practices, where old customs may remain. So how are the local protocols for swabbing in practice – if they even do swab? Not disinfecting may risk patient safety. We aim to put a focus on the venipuncture disinfection procedure in practice when measuring blood alcohol for clinical matters and if their procedure refers to a guideline.
Specialized biomedical laboratory scientists (BLS) are typically responsible for the phlebotomy procedure in Denmark, thus questionnaires were sent to the relevant BLS in 2020 to map disinfection procedures in all Danish hospitals and affiliated blood draw clinics (n = 58).
The response rate was 93% (54/58). We observed an inter-laboratory dissimilarity in swabbing procedures, when measuring blood alcohol: A quarter did not use any disinfectant (26%), while the remaining disinfected with ethanol 55%, isopropanol 13%, and 6% with ethanol/chlorhexidine. Of the five Danish regions, three had a regional guideline (3/5), otherwise the swabbing protocol was locally based. There was a regional difference in disinfecting or not (Chi2 p < 0,0001).
Danish protocols do not always parallel international literature and international guidelines. Not applying disinfectant may jeopardize patient safety. Laboratories are encouraged to work with evidence-based practice or follow newest standardized international guidelines.
Serum and plasma are used for measurements of microRNAs (miRNAs) as biomarkers of various diseases. However, no consistent findings have been obtained regarding differences in serum and plasma levels of miRNAs. The purpose of this study was to clarify differences in serum and plasma levels of total miRNAs and their time-course changes after blood collection.
Venous blood was collected from healthy men, and samples were prepared at the time points of 0, 15, 30, 60 and 180 min after blood collection for plasma and after clot formation for serum. Levels of total miRNAs were analyzed by the hybridization method using the 3D-Gene miRNA Oligo chip.
About one third of 2632 miRNAs tested showed levels high enough for comparison of serum and plasma levels and for investigation of their time-course changes. Levels of 299 miRNAs at time 0 were significantly different in serum and plasma. Levels of representative platelet-derived miRNAs including miR-185-5p, -22-3p and -320b were significantly higher in plasma than in serum, while levels of representative erythrocyte-derived miRNAs including miR-451a, -486-5p and -92a-3p were not significantly different in serum and plasma. Plasma levels of 173 miRNAs and 6 miRNAs showed significant decreasing and increasing tendencies, respectively, while there were no miRNAs in serum that showed significant time-course changes.
The results suggest that careful attention should be paid when comparing serum and plasma levels of miRNAs and that plasma samples should be prepared early after blood collection.
Clinical decision making depends mostly on appropriate application of numerical pathology reports from laboratory results, interpreted by comparison with reference intervals. We determined serum reference intervals of micronutrients, vitamins, and detectable interleukins among healthy adults in South-Western Nigeria.
This prospective study used a priori selection approach in blood-donors. They were screened for conditions that could elicit cytokine production.
Serum micronutrients were assayed using Atomic Absorption Spectrophotometry; interleukins and vitamins by high Performance Liquid Chromatography. The reference intervals (RIs) were estimated at 2.5th percentile and 97.5th percentile.
One hundred and eighteen (118) apparently healthy subjects, aged 18–56 years; 113 (95.8%) being 18–44years, and 5 (4.2%): 45–56 years; mostly males, 13 (11.02%) females, all Africans of Yoruba ethnicity.
Estimated reference limits were: Zinc: 9.49–20.54 μmol/L, Selenium: 0.50–1.11 μmol/L, Copper: 13.86–27.97 μmol/L, Iron: 14.19–32.07 μmol/L, Manganese: 6.24–16.37 nmol/L; Magnesium: 0.78–1.62 mmol/L.
Vitamins: A-1.08–2.39 μmol/L; D: 59.89–164.42 μmol/L; E: 7.13–19.45 μmol/L; K: 0.16–0.42 nmol/L; B1: 74.09–201.56 nmol/L; B6: 0.12–0.29 nmol/L; B12: 155.55–407.96 pmol/L; C: 47.74–112.99 μmol/L.
Detected interleukins (IL-1 to IL-18): IL-1: 0.58–1.24 ng/L, IL-2: 0.09–0.18 ng/L, IL-3: 0.39–0.89 ng/L, IL-4: 0.27–0.58 ng/L, ….to IL-18: 0.74–1.56 ng/L.
The RI derived from this study for serum micronutrient, vitamin and interleukin concentrations are the first published for our population. They are in general agreement with those published from other geographical climes but there are differences at the lower and upper limits of the RI. The study reinforces the importance of deriving RI for the population that a clinical laboratory will serve.
Objectives: The objectives were to evaluate blood additives that combined lithium heparin (LH)-salt with glyceraldehyde (GLY) or d-mannose (MAN) for preserving glucose levels in plasma samples and to simultaneously determine the compatibility of these additives with 14 other biochemical tests.
Blood samples from 40 subjects, equally divided into healthy and diabetic groups, were collected using five different additives. The three most effective additives, LH/GLY, LH/MAN, and LH/GLY/MAN, were selected for ensuring the best preservation of glucose levels and compatibility with 14 biochemical tests. One-way analysis of variance was used to analyze the mean paired differences of glucose level and biochemical tests. Simultaneously, the clinical criteria from Johns Hopkins Hospital were used to guide the interpretation and set acceptable thresholds for measurements that exceeded the standards.
The combination of 160 mmol/L GLY, 8.4 mmol/L MAN, and LH, maintained glucose levels at approximately 93.4–93.7 % for healthy subjects and 91.3–92.8% for subjects with diabetes mellitus over 8 h. The mean paired differences of glucose levels in preservation were statistically insignificant. The biases in 14 biochemical tests for LH/GLY/MAN and LH/MAN remained within the acceptable clinical criteria during the 8 h.
Combining 160 mmol/L GLY, 8.4 mmol/L MAN, and LH, proved more effective in maintaining glucose levels than individual additives or the conventional sodium fluoride preservative. It did not yield clinical discrepancies in the 14 biochemical tests during 8 h at room temperature.
This study evaluated the clinical and analytical performances of the Access HBsAg and the Access HBsAg Confirmatory assays on the DxI 9000 Access Immunoassay Analyzer (Beckman Coulter, Inc.).
Diagnostic specificity and sensitivity of the Access HBsAg and Access HBsAg Confirmatory assays were evaluated by comparing the Access assays to the final HBsAg sample status determined using the Architect, PRISM, or Elecsys HBsAg assays, along with Architect or PRISM HBsAg Confirmatory assays. Imprecision, sensitivity on seroconversion panels, analytical sensitivity on WHO, and recognition of HBV variants were also evaluated.
A total of 7534 samples were included in the analysis (6047 blood donors, 1032 hospitalized patients, 455 positive patients’ samples). Access HBsAg assay sensitivity and specificity were at 100.00% (99.19–100.0) and 99.92% (99.82–99.97), respectively. Sensitivity of Access HBsAg Confirmatory assay was 100.00% (99.21–100.0) on the 464 HBsAg positive samples. The use of a high positive algorithm for the Access HBsAg assay, wherein samples with S/CO ≥ 100.00 were considered positive without requiring repeat or confirmatory testing, was successfully evaluated with all 450 specimens with S/CO greater than 100.00 (sensitivity 100.00%; 99.19–100.0). Access HBsAg assay demonstrated good analytical performance, equivalent recognition of seroconversion panels compared to Architect assay, and an analytical sensitivity between 0.022 and 0.025 IU/mL. All HBV genotypes, subtypes and mutants were well detected without analytical sensitivity loss.
Access HBsAg and Access HBsAg Confirmatory assays demonstrated robust performances. They provide low samples volume requirements and a simplified process, no systematic retesting for high positive samples.
Prothrombin/Protein Induced by Vitamin K Absence-II (PIVKA-II) is a candidate biomarker of hepatocellular cancer, recommended both for diagnostics and monitoring. The aim was to evaluate biological variation (BV) of serum PIVKA-II.
Within-subject (CVI) and between-subject (CVG) BV estimates were assessed in 14 healthy volunteers in a 6-week protocol. Serum concentrations of PIVKA-II were measured by a Roche Elecsys PIVKA-II diagnostic kit (cobas e8000). Precision (CVA) was assessed from duplicate measurements of all volunteers' samples. Two methods were used for the estimation of CVI: SD-ANOVA and CV-ANOVA method. We calculated the index of individuality (II) and reference change value. The experiment was fully compliant with EFLM database checklist.
The CVI of PIVKA-II in healthy persons, as calculated by two statistical methods, were 8.2% (SD-ANOVA with CVA of 3.2%) and 9.4% (CV-ANOVA) with CVA of 2.7%). The CVG was 19.5% (SD-ANOVA), and respective II and RCV were 0.42 and 24.4%.
CVI and CVG of PIVKA-II were 8.2% and 19.5%, respectively, with CVA below 4%. The low II and RCV below 25% enable the use of this biomarker both for diagnostics and monitoring. More data are needed before the introduction of PIVKA-II into clinical practice.
Coronavirus disease 2019 (COVID-19) has a wide spectrum of clinical severity. A cytokine storm is associated with COVID-19 severity. Of these, IL-6 is significantly associated with higher mortality and is also a marker for predicting disease prognosis. IL-6 may act as a target for therapeutics and, a blockade of IL-6 function by Tocilizumab has been described as a treatment of the inflammatory process COVID-19-related. This study aims to describe our experience comparing two different methods, in detail Human IL-6 Instant ELISA and the Elecsys IL-6 based on ECLIA, for the IL-6 assessment.
IL-6 levels from serum samples of 104 COVID-19 patients, admitted to the AOU Careggi (Hospital in Florence -Italy), were assessed by using the two above-mentioned methods, and the results were analysed through Passing-Bablok regression fit and Bland-Altman plot.
The regression exhibited a linear relation between the methods with a regression equation (y = - 0.13 + 0.63 x; 95 % C.I. intercept = − 0.13 to 4.55; 95 % C.I. slope = 1.03 to 1.26 with R2 = 0.89, p > 0.05), showing a positive slope. The agreement of the two methods reported a bias of −25.0 pg/mL. Thus, the two methods correlate but do not agree in terms of numeric results.
The two assays showed good comparability. However, because of the extremely wide linear range of the ECLIA, its throughput and its capacity for immune profiling, it represents an interesting emerging technology in the immunology field.
Patients with VEXAS syndrome carry mutations of UBA1 gene coding for the E1 enzyme. The three most frequent mutations are p.M41T(122T > C), p.M41V (c.121A > G), and p.M41L (c.121A > C) in codon 41 of exon 3. Currently, sanger sequencing was mainly used to detect these mutations, which has low sensitivity and low throughput. There is a need of high sensitivity, simple and high throughput method to characterize patients with VEXAS syndrome.
Based on our proprietary XNA technology, we have developed a QClamp® Plex platform to detect eight mutations in a single reaction using the Luminex xMap technology. The assay sensitivity, specificity and precision were subsequently evaluated. Furthermore, the reference interval and clinical sensitivity/specificity were estimated using clinical healthy/positive DNA samples and the sanger sequencing method was used for comparison.
With spiking synthetic mutant DNA in wildtype GM24385 cell line DNA, this assay can detect UBA1 mutations with a detection limit of variant allele frequency (VAF) at 0.1–5%. Our assay shows 100% concordance with Sanger sequencing results when used for analyzing 15 positive and 19 negative clinical samples.
The QClamps® Plex UBA1 Mutation Detection Assay is a quicker, simpler, and more sensitive assay that can accurately detect the UBA1 mutations even at early stages with low mutation frequency.
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