Annals of Clinical Biochemistry最新文献

Background: International guidelines give greatly varying definitions of 25-hydroxyvitamin D (25OHD) insufficiency and deficiency. Vitamin D testing is increasing despite 2016 UK guidance for adults advising routine vitamin D supplementation October-March and year-round for high risk groups. A service evaluation of vitamin D testing and biochemical osteomalacia in the North-East of Scotland (57-58°N) could inform definitions and testing guidance.

Methods: We identified adult 25OHD requests 8/7/2008-29/2/2020 and albumin-adjusted serum calcium (aCa), parathyroid hormone (PTH) and alkaline phosphatase (ALP) within 6 months of 25OHD testing. After excluding renal impairment and liver disease, we defined biochemical osteomalacia as ALP >130 IU/L and aCa <2.0 mmol/L and elevated PTH >9.2 or >6.8 pmol/L, depending on the assay. Possible biochemical osteomalacia was defined as 2 of these abnormalities in the absence of the third measurement. From these cases anonymised clinical data were then examined to confirm the diagnosis of osteomalacia.

Results: 25,379 eligible patients had 25OHD measured: 25% were <25 nmol/L (6,258/25,379) and 18% <20 nmol/L (4,536/25,379). 0.5% (126/25,379) of eligible patients had biochemical or possible biochemical osteomalacia. After reviewing clinical records, only 0.1% (29/25,379) had clinically confirmed osteomalacia, equivalent to 2-3 cases/y for a population of 0.5 million, none of the untreated cases of clinically confirmed osteomalacia had 25OHD >25 nmol/L. For the entire tested population, when 25OHD was <25 nmol/L untreated osteomalacia confirmed by clinical records was rare (0.4%).

Conclusions: Osteomalacia is rare in North-East Scotland. Our data call into question designating 25OHD 25-50 nmol/L 'insufficiency'. The risk of osteomalacia even when 25OHD is <25 nmol/L is very low.

Objectives: Neonatal respiratory distress syndrome (NRDS) is the most common respiratory disease in preterm infants (PIs). The implication of Angiopoietin-like 4 (ANGPTL4) was reported in lung diseases. We delved into the role of serum ANGPTL4 in NRDS diagnosis/prognosis.

Methods: Totally 256 PIs were prospectively selected, including 128 NRDS infants and 128 non-NRDS PIs. NRDS infants were assigned into Survival and Death groups. ANGPTL4 level in PIs and its diagnostic and prognostic value for NRDS were separately assessed by ELISA and receiver operating characteristic curve. The independent risk factors (IRFs) for death in NRDS infants were analysed by multivariate logistic regression.

Results: NRDS infants exhibited reduced gestational age, birth weight, and 5 min Apgar score. ANGPTL4 level rose in NRDS infants, and increased with NRDS severity. Serum ANGPTL4 level was negatively correlated with 5 min Apgar score in NRDS infants. The area under the curve of serum ANGPTL4 for the diagnosis of NRDS was 0.902, with 88.28% sensitivity, 86.72% specificity, and 255.98 ng/mL cut-off value; the AUC for the diagnosis of severe NRDS was 0.741, with 66.67% sensitivity, 79.52% specificity, and 625.5 ng/mL cut-off value. Low gestational age, birth weight and 5 min Apgar score, severe NRDS, and elevated serum ANGPTL4 levels were IRFs for death in NRDS infants. NRDS infants with increased serum ANGPTL4 level displayed decreased survival rate and short survival time.

Conclusions: ANGPTL4 exhibited high diagnostic value and predictive value for death in NRDS, and it served as a biomarker for the diagnosis and prognosis of NRDS.

Atherosclerotic cardiovascular disease remains a major cause of premature death in the UK. Lipid testing is a key tool used to assess cardiovascular risk and guide clinical management decisions. There are currently no national guidelines to provide evidence-based recommendations on lipid testing and reporting for UK laboratories and clinicians. Here we present consensus guidance, following a review of published evidence by a multidisciplinary group of UK experts across a range of laboratory and clinical services. Recommendations include: the composition of a standard lipid profile; indications for, and composition of, an enhanced lipid profile including apolipoprotein B and lipoprotein (a); use of the Sampson-NIH calculation for LDL-c estimation; and guidance on when to flag abnormal results. This consensus guidance on lipid testing and reporting in the UK has been endorsed by HEART UK and The Association for Laboratory Medicine.

We describe the utility of 'folic and folinic acid load tests' in the investigation of a 26-year-old woman with persistently low serum folate and moderate hyperhomocysteinaemia unresponsive to folic acid supplements. Serum folate, plasma 5-methyltetrahydrofolate (5-MTHF), red cell 5-MTHF and plasma total homocysteine at baseline, 2-h, 4-h and 2- or 4-days (if applicable) post administration of a large dose of oral folic acid, or oral or parenteral folinic acid were measured. The tests confirmed non-compliance but also suggested an unsuspected possible defect in the folate pathway based on differential response to folic versus folinic acid supplements. The folic and folinic acid load tests identify non-compliance and can help identify possible defects related to the absorption, transportation, or metabolism of folate.

Background: Grossly lipaemic samples are a significant cause of analytical errors, potentially impacting patient care. The causes of lipaemia are varied and often unavoidable, while methods to reduce lipaemia through gold-standard ultracentrifugation are limited by availability, transportation and cost. Benchtop centrifugation has been proposed as an alternative method to reduce lipaemia.

Methods: Fifty-three grossly lipaemic serum samples (lipaemia >201.8 mg/dL) that were unsuitable for analysis were selected and centrifugated at 18840 g for different time-periods with lipaemia measured prior to and after centrifugation. Core analytes were measured on serum samples free of lipaemia before and after 30 min of centrifugation at 18840 g to assess the effect of the centrifugation process.

Results: After centrifugation for 5 min, 90% of grossly lipaemic samples were either ideal (lipaemia <50 mg/dL) or adequate (lipaemia 50.1-201.7 mg/dL) for analyte testing. All samples were either adequate or ideal for testing following centrifugation for 30 min. Although some analytes showed a statistically significant change in the measured concentration post high-speed centrifugation, none had clinically significant changes according to analyte specific reference change value (RCV) analysis. Aspartate aminotransferase (AST) and creatine kinase (CK) demonstrated the most notable reductions in activity, but these did not exceed their RCV.

Conclusions: Benchtop centrifugation shows potential laboratory utility in reducing lipaemia whilst maintaining clinically reliable results, however small sample sizes preclude firm conclusions. Further research is warranted to increase the sample size with finer time-point tuning, sub-group analysis and temperature analysis, due to the potential for sample heat injury, to balance practicality and accuracy.

Background: The escalating prevalence of diabetes underscores the need for precise diagnostic tools to facilitate effective management. Hemoglobin A1c (HbA1c) is a crucial biomarker for long-term glycemic control in diabetic patients. Point-of-care testing (POCT) for HbA1c offers rapid, accessible alternatives to conventional laboratory methods, but uncertainties persist regarding the accuracy and reliability of POCT assays.

Methods: This study evaluates the analytical performance of two boronate-affinity based HbA1c POCT assays, the GreenCare A1c and Cera-Stat HbA1c. Various analytical parameters including precision, linearity, comparison, and accuracy are assessed following guidelines from Clinical and Laboratory Standards Institute (CLSI), with results applied to certification criteria from the National Glycohemoglobin Standardization Program (NGSP) and International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). Furthermore, 52 and 13 frozen EDTA whole blood samples were respectively used for additional evaluation of accuracy and interference due to Hb variants for the GreenCare A1c assay.

Results: Both GreenCare and Cera-Stat demonstrated good precision (repeatability CV% 1.5-1.9 and total imprecision CV% 1.6-2.2), linearity (R² = 0.9996 & 0.9990), and correlation (r = 0.982 & 0.978) with an established HbA1c analyzer, the Bio-Rad D100. The GreenCare also exhibited good accuracy with frozen EDTA samples with known HbA1c values. Both assays met the certification criteria from NGSP and IFCC, classifying them as "standard" according to IFCC model for quality targets for HbA1c.

Conclusions: This evaluation affirms the reliability of GreenCare and Cera-Stat POCT assays for HbA1c measurements, which can potentially reduce unnecessary referrals and enhance the overall quality of diabetes diagnosis and treatment.

Background: ML predictive models have shown their capability to improve risk prediction and assist medical decision-making, nevertheless, there is a lack of accuracy systems to early identify future rapid CKD progressors in Colombia and even in South America.

Objective: The purpose of this study was to develop a series of interpretable machine learning models that predict GFR at 6-months, 9-months, and 12-months.

Study design and setting: Over 29,000 CKD patients stage 1 to 3b (estimated GFR, <60 mL/min/1.73 m²) with an average of 3-year follow-up data were included. We used the machine learning extreme gradient boosting (XGBoost) to build three models to predict the next eGFR. Models were internally and externally validated. In addition, we included SHapley Additive exPlanation (SHAP) values to offer interpretable global and local prediction models.

Results: All models showed a good performance in development and external validation. However, the 6-months XGBoost prediction model showed the best performance in internal (MAE average = 6.07; RSME = 78.87), and in external validation (MAE average = 6.45, RSME = 18.94). The top 3 most influential features that pushed the predicted eGFR value to lower values were the interpolated values for eGFR and creatinine, and eGFR at baseline.

Conclusion: In the current study we have developed and validated machine learning models to predict the next eGFR value at different intervals. Furthermore, we attempted to approach the need for prediction explanation by offering transparent predictions.

Vitamin B₁₂ (cobalamin; B₁₂) is an essential micronutrient, but deficiency is common. The prompt diagnosis and treatment of B₁₂ deficiency protects against megaloblastic anaemia, neuropathy and neuropsychiatric changes. Biomarkers of B₁₂ status include the measurement of serum B₁₂ (also known as total B₁₂ or serum cobalamin), holotranscobalamin (holoTC or 'active B12'), methylmalonic acid (MMA) and total plasma homocysteine (Hcy). There is no 'gold standard' test for deficiency and the sensitivity and specificity of each biomarker for the evaluation of B₁₂ status is affected by analytical and biological factors that may confer a high degree of diagnostic uncertainty. Limited access to technical and clinical expertise can lead to an over-reliance on the serum B₁₂ test, which is readily available and highly automated. In some cases, the sequential use of different B₁₂ status biomarkers or the calculation of a composite B₁₂ status score, derived from a panel of B₁₂ biomarkers and adjusted for folate status and age, can be used to detect deficient states that may otherwise be overlooked when using a single biomarker approach. This review summarizes the utility of B₁₂-related biomarkers and describes approaches to their application and interpretation.

Background: Lysophosphatidylethanolamines (lyso-PEs) are the partial hydrolysis products of phosphatidylethanolamine. Although lyso-PEs are important biomarkers in various diseases, their determination is limited by the lack of simple and efficient quantification methods. This study aims to develop an improved quantitative method for the determination of lyso-PEs and its application to an epidemiological study.

Methods: Single reaction monitoring channels by collision-induced dissociation for seven lyso-PEs were established using liquid chromatography-tandem mass spectrometry. Plasma lyso-PEs were extracted with a single-phase method using an isotopically labelled internal standard for quantification. The proposed method was adopted to define lyso-PEs in plasma samples of children aged 9-12 years living in Sapporo, Japan.

Results: The limit of detection and limit of quantification for each lyso-PE ranged between 0.001-0.015 and 0.002-0.031 pmol/μL, respectively. Recoveries were found to be > 91% for all the species. The analysis results of children's plasma showed that the total lyso-PE concentrations in boys (n = 181) and girls (n = 161) were 11.53 and 11.00 pmol/μL (median), respectively. Participants were further classified by the percentage of overweight and subgrouped as underweight (n = 12), normal range (n = 292), or overweight (n = 38). Interestingly, the reduction of lyso-PE 16:0 and increased lyso-PE 22:6 were observed in overweight children compared with normal range (Fold change: 0.909 and 1.174, respectively).

Conclusions: This study successfully established a simple quantitative method to determine lyso-PE concentrations. Furthermore, our method revealed the possible relation between plasma lyso-PEs and overweight status.