Electronic Journal of the International Federation of Clinical Chemistry and Laboratory Medicine最新文献

Background: Breath analyser tests are used worldwide to obtain proof of alcohol intoxication and often used in the conviction of traffic violators. These tests are conducted to quickly and painlessly determine the existing concentration of alcohol in arterial blood by measuring the amount of ethanol in exhaled breath, which can be identified with an electrochemical sensor.At present, the calibration and maintenance of analysers used for these tests are typically performed regularly but lack quality control. Consequently, test results may not be accurate because of calibration deterioration.The aim of this study was to develop and evaluate the uncertainty of control materials used in breath-alcohol testing at the Bangkok Metropolitan Police Station.

Material and methods: Ethyl alcohol (99.99%; Certified Reference Material grade) diluted at three different concentrations was kept under design conditions. The concentrations were 28, 67, and 134 mg/dL, determined by performing headspace gas chromatography, and the uncertainty was set as ±1.3925, ±2.8736, and ±1.8231 mg/dL (±4.97%, ±4.29%, and ±2.72% for the concentrations, respectively), as per ISO Guide 35:2017.

Results: The total error percentages of the developed control materials were 4.97%, 4.29%, and 2.72% for concentrations of 28, 67, and 134 mg/dL, respectively. Each concentration of the materials was tested by using measurements from 70 breath-alcohol analysers belonging to the Bangkok Metropolitan Police Station.

Conclusion: These control materials are applicable to quality assurance and standards tests and may help to ensure the accuracy of breath-alcohol testing in the future.

Lithium is the first-line treatment for maintenance therapy in bipolar disorder. It is an effective mood stabilizer agent, and may have potential benefits in neuroprotection and reducing the risk of suicide. Toxicity has been a concern in recent decades, particularly in older adults (≥60 years). In 2019, the Older Adults Task Force within the International Society for Bipolar Disorder (ISBD) published recommendations for age-stratified lithium therapeutic ranges for therapy of Older Age Bipolar Disorder (OABD), namely 0.4 - 0.8 mmol/L for ages 60 to 79 and 0.4 - 0.7 mmol/L for ages 80 and above. Clinical laboratory practice surveys in Canada indicated that adoption and implementation of the proposed ranges has been limited to date. In this article, we describe the approach and steps taken to evaluate and implement recommended lithium therapeutic ranges in Ontario and other provinces in Canada for laboratory quality improvement. Sources of variation in lithium reporting practices are discussed and shared here to highlight potential barriers to implementation. The overall goal of this article is to bring attention across the global laboratory community that lower lithium therapeutic target ranges in older patients are crucial for patient safety in OABD.

Dasatinib is a tyrosine kinase inhibitor drug used for chronic myeloid leukaemia (CML) treatment. Chylothorax has been rarely reported as a secondary effect of dasatinib occurring especially in long-term treated patients, although its pathophysiology is not yet fully understood. Laboratory analysis of the pleural effusion is crucial for chylothorax diagnosis. We report a case of a 53-year-old male patient presenting a chylothorax after 14 years of dasatinib therapy where the clinical laboratory was key in the diagnosis.

The COVID-19 pandemic impacted delivery of health services. The aim of our study was to determine the impact of COVID-19 disease on pre-analytical blood sample haemolysis by modelling the daily haemolysis rates variations pre and post COVID-19 infections. Ethics approval was obtained prior to study commencing. Interrupted Time Series data analysis was conducted on UK National Health Service Acute Admissions Unit 25-month (1 February 2019 to 28 February 2021) biochemistry (total and haemolysed) blood sample dataset. Interruption was set on 23 March 2021, the start of the first UK lockdown. Daily haemolysis rate (% samples haemolysed) data were fitted with a spline curve to determine influence of haemolysis rates on short or medium-term temporal trends. Linear regression was performed so as to determine long-term temporal trends pre- and post-intervention. There were 32,316 biochemistry blood sample results: 19,058 pre and 13,258 (342 days) from the post-intervention period. Overall median daily haemolysis rate was 7.3% (range: 0-30.6%), 7.7% pre-intervention versus 6.5% post-intervention (p<0.0001). The proportion of haemolysis cases negatively correlated with the number of samples processed (rho=0.09; p=0.01). The pre-intervention slope was -1.70 %.y^-1, y intercept 9.04%; post-intervention slope was -1.88%.y^-1, y intercept was 10.2%; with no difference in either the slope (p=0.87) or intercept (p=0.16). There was no association between short-term variation in haemolysis rates with changes in practice due to COVID-19 disease and the disease itself. The negative correlation between haemolysis rate and the number of samples processed highlights the importance of continued venepuncture practice to facilitate haemolysis rate reduction.

The revolution in electronic publishing now allows for papers to be continuously critiqued through letters to the editor, online comments, tweets and other means. However, established top-ranked journals still pose serious barriers regarding cultivation, documentation and dissemination of post publication critiques (1). To improve on this situation, Hardwicke et al. published a set of rules, one being for journals to actively encourage and highlight post publication critique to their readership. In this commentary, I present a case whereby the editors of a top ranked journal hindered the discussion/debate between authors and expert readers. Highlighting and publishing such cases will likely put pressure on journals to modify their current policies and actively encourage post publication review. Like Hardwicke et al., we believe that post publication review is a major vehicle for advancing and accelerating science, by encouraging debates, resolving disagreements and revealing flaws in already published (and in many cases seemingly high-impact) papers.

Background: Inflammatory and hematological markers are used extensively for early prognostication and monitoring in COVID-19.We aimed to determine whether routinely prescribed laboratory markers can predict adverse outcome at presentation in COVID-19.

Methods: This retrospective observational study was performed on 401 samples collected between July to December 2020 from COVID-19 positive subjects, admitted at All India Institute of Medical Sciences, Delhi, India. Clinical details and laboratory investigations within 3 days of COVID-19 positivity were obtained. Clinical outcomes were noted from patient medical records, till discharge or death. Laboratory parameters, with individually defined cut-offs, were used, either singly or in combination to distinguish survival and death for those having severe and non-severe disease at initial presentation.

Findings: Total Leukocyte count, Absolute neutrophil count, Neutrophil to Lymphocyte ratio, C-Reactive Protein (CRP), Interleukin-6 (IL-6), Lactate Dehydrogenase, Ferritin and Lymphocyte to CRP ratio (LCR) were significantly altered at presentation in severe COVID-19 as compared to non-severe cases; and, also in those who died due to COVID-19 compared to those who survived. A combination of four markers, CRP (≥3.9mg/dL); IL-6 (≥45.37pg/ml); Ferritin (≥373ng/mL); 1/LCR ≥0.405 was found to strongly predict mortality in cases with non-severe presentation as also in severe cases.

Conclusion and interpretation: The combination of routinely used markers, CRP, IL-6, Ferritin and 1/LCR can be used to predict adverse outcomes, even in those presenting with mild to moderate disease. This would identify subset of patients who would benefit from closer monitoring than usual for non-severe disease.

Background: The effect of glucose interference on creatinine measurement by Jaffe kinetic method differs between serum and urine specimens. We investigated the effects of creatinine concentration and specimen dilution on glucose interference with urine creatinine measurement.

Methods: Leftover serum and urine specimens were collected and stored at -20°C until study. Serum specimens were mixed to make 5 glucose concentrations ranging from <5.6 to 27.8 mmol/L, each group consisting of 5 levels of creatinine concentration ranging from <45 to 354 μmol/L. Urine specimens were divided into 5 groups of creatinine concentration ranging from <1,769 to >7956 μmol/L, each sample was spiked with glucose powder to produce 5 aliquots with glucose concentrations ranging from 0 to 666 mmol/L. Urine samples were automatically diluted 1:20 before analysis. Percent interference of creatinine measurement by Jaffe kinetic method was calculated using enzymatic method as the reference.

Results: A total of 148 serum samples and 335 urine samples were analyzed. In serum, glucose interference with Jaffe creatinine measurement was found if creatinine concentrations were 177 μmol/L or less, corresponding to 3,540 μmol/L or less in urine specimens prior to 1:20 dilution. The degree of interference was greater when glucose concentration was higher or creatinine concentration was lower.

Conclusions: When creatinine concentration and specimen dilution were considered, the effects of glucose interference on Jaffe creatinine measurement were similar in serum and urine specimens, and was found when creatinine concentrations in serum or diluted urine were 177 μmol/L or less.

Background: The added value of Anti-Müllerian hormone (AMH) measurement is recognized for several clinical applications such as assessment of the ovarian reserve, monitoring of in vitro fertilization protocol or in the field of oncofertility. Our study objective was to determine the performances of a novel fully automated chemiluminescent assay for AMH testing.

Methods: We evaluated the performances of the Maglumi^® 800 AMH chemiluminescent immunoassay that applies N-(4-Aminobutyl)-N-ethylisoluminol (ABEI) labels. Assay imprecision was assessed with two levels of control materials. Method comparison was performed with an ultrasensitive AMH ELISA assay (Ansh Laboratories, Inc, Webster, TX, USA) with 88 patients' samples.

Results: The within-run and between-run coefficients of variation (CVs) were below 3% for both low and high internal quality controls. The automated and ELISA methods were significantly correlated. Bland-Altman plot evidenced a bias between the methods with a mean bias of 0.6 ng/mL.

Conclusions: Our preliminary evaluation showed overall good analytical performances for the Maglumi^® AMH fully automated immunoassay and good concordance with a routinely used assay.

Celiac disease (CD) is a systemic autoimmune pathological condition caused by the intake of gluten in genetically predisposed individuals. Despite its wide prevalence, it remains an underdiagnosed disease since a large percentage of individuals who suffer from the condition do not have the classic symptoms described for the disease. We present the case of a 43-year-old man with severe iron deficiency and asthenia. We found high levels of anti-transglutaminase and anti-endomysium antibodies, a severe intraepithelial lymphocytosis, 3A Marsh-Oberhuber classification upon gastroscopy and the presence of HLA-DQ2 and HLA-DQ8 heterodimers. The patient was diagnosed with CD and was placed on a gluten-free diet. After 19 months, an improvement in biomarkers of CD and other biochemical parameters was observed. A delay in the diagnosis of CD can produce nutritional deficiencies, such as iron deficiency which may not improve even with oral iron treatment. In similar clinical presentation, the laboratory can advance a diagnosis of CD.