Clinical Chemistry Research Articles

Analytical performance evaluation of the Mindray enzymatic assay for hemoglobin A1c measurement

Hemoglobin A1c (HbA1c) plays a crucial role in diabetes management. We aimed to evaluate the analytical performance of a new enzymatic method kit for HbA1c measurement. The performance of the enzymatic method, including precision, accuracy, and linearity, was evaluated. Moreover, the interference effect from conventional interferents, Hb derivatives, Hb variants, and common drugs were assessed. In addition, the agreement of HbA1c results was compared between enzymatic methods, cation-exchange high-performance liquid chromatography (HPLC), and immunoassays. The intra-assay, between-assay, and total precision of HbA1c were all lower than 2%. HbA1c showed good linearity within the range of 3.96–20.23%. The enzymatic assay yielded results consistent with the external quality control samples, with a bias of less than ± 6% from the target values. The enzymatic method showed no interference from bilirubin, intralipid, vitamin C, Hb derivatives, common Hb variants, as well as antipyretic analgesics and hypoglycemic drugs. The HbA1c results of the enzymatic assay showed good agreement and accuracy compared to those obtained from the HPLC method and the immunoassay. The enzymatic method kit performed on the BS-600M chemistry analyzer is a reliable and robust method for measuring HbA1c. It is suitable for routine practice in clinical chemistry laboratories.

Association of inflammatory markers and ultrasonographic indicators of endothelial (dys)function in humans

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Austrian Science Fund (FWF) Introduction It has been widely known that chronic inflammation is a crucial factor in the process of atherogenesis and atherosclerosis. Also, endothelial dysfunction presents the first and still reversible step of that process.(1) It is a challenge to find a laboratory marker whose levels would be informative about the extent of endothelial dysfunction and atherogenesis in humans. Purpose The aim of the present study was to determine associations between markers of chronic, low-grade inflammation and ultrasonographic indicators of endothelial (dys)function in healthy volunteers (H) and in patients with metabolic syndrome (MS). Methods Any kind of clinically manifest acute inflammatory or infectious disease, as well as chronic inflammatory, autoimmune or malignant disease was an exclusion criterion for participation. Serum levels of C-reactive protein (CRP) were measured using standard clinical chemistry analyser, and serum levels of interleukin-6 (IL-6) using electro-chemiluminescence immunoassay. Blood vessel wall function was quantified as flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD), which were measured automatically and continuously using the ultrasound device with linear probe (10 MHz) and the software for ultrasound blood vessel diameter analysis,(2) following currently valid guidelines.(3,4,5) Results A total of 130 individuals were enrolled in the study (65 H and 65 MS), with a median age of 56 (IQR 50.0, 60.0) years and 47.7% women in each group. CRP and IL-6 levels, although being very low and within the intervals that are considered normal in everyday clinical practice for both groups [CRP - H: 1.2 (0.6, 2.3), MS: 2.4 (1.2, 5.5) μg/mL; IL-6 - H: 2.3 (1.7, 3.0), MS: 4.1 (2.7, 6.8) pg/mL], were significantly higher in the MS compared to H (both p<0.001). The MS group also had significantly lower FMD (p=0.013) and NMD (p=0.033) compared to H. In H, IL-6 levels were significantly negatively correlated with FMD (r=-0.46, p<0.001), but not with NMD; whereas no significant associations of IL-6 levels with FMD or NMD were observed in the MS group. CRP levels were not significantly associated with FMD or NMD in neither the H nor MS group. Conclusion Higher IL-6 serum levels in the absence of acute inflammatory or infectious disease are significantly associated with lower FMD values among individuals with low risk for cardiovascular diseases, who are still considered healthy. Direct correlation is attenuated and lost among individuals with developed clinical signs of metabolic syndrome, probably due to its complex pathophysiology, as well as redundant and interdependent mechanisms contributing to the occurrence of endothelial dysfunction in such an environment. Further investigation on larger cohorts is needed to determine whether IL-6 serum levels could serve as a marker of endothelial dysfunction in individuals without clinically developed traditional risk factors and symptoms of cardiovascular disease.

An Optimized Method for LC-MS-Based Quantification of Endogenous Organic Acids: Metabolic Perturbations in Pancreatic Cancer.

Accurate and reliable quantification of organic acids with carboxylic acid functional groups in complex biological samples remains a major analytical challenge in clinical chemistry. Issues such as spontaneous decarboxylation during ionization, poor chromatographic resolution, and retention on a reverse-phase column hinder sensitivity, specificity, and reproducibility in multiple-reaction monitoring (MRM)-based LC-MS assays. We report a targeted metabolomics method using phenylenediamine derivatization for quantifying carboxylic acid-containing metabolites (CCMs). This method achieves accurate and sensitive quantification in various biological matrices, with recovery rates from 90% to 105% and CVs ≤ 10%. It shows linearity from 0.1 ng/mL to 10 µg/mL with linear regression coefficients of 0.99 and LODs as low as 0.01 ng/mL. The library included a wide variety of structurally variant CCMs such as amino acids/conjugates, short- to medium-chain organic acids, di/tri-carboxylic acids/conjugates, fatty acids, and some ring-containing CCMs. Comparing CCM profiles of pancreatic cancer cells to normal pancreatic cells identified potential biomarkers and their correlation with key metabolic pathways. This method enables sensitive, specific, and high-throughput quantification of CCMs from small samples, supporting a wide range of applications in basic, clinical, and translational research.

Zinc and Inflammatory Bowel Disease: From Clinical Study to Animal Experiment.

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract (GI) with a high incidence rate globally, and IBD patients are often accompanied by zinc deficiency. This review aims to summarize the potential therapeutic value of zinc supplementation in IBD clinical patients and animal models. Zinc supplementation can relieve the severity of IBD especially in patients with zinc deficiency. The clinical severity of IBD were mainly evaluated through some scoring methods involving clinical performance, endoscopic observation, blood biochemistry, and pathologic biopsy. Through conducting animal experiments, it has been found that zinc plays an important role in alleviating clinical symptoms and improving pathological lesions. In both clinical observation and animal experiment of IBD, the therapeutic mechanisms of zinc interventions have been found to be related to immunomodulation, intestinal epithelial repair, and gut microbiota's balance. Furthermore, the antioxidant activity of zinc was clarified in animal experiment. Appropriate zinc supplementation is beneficial for IBD therapy, and the present evidence highlights that alleviating zinc-deficient status can effectively improve the severity of clinical symptoms in IBD patients and animal models.

The diagnostic accuracy of quality control rules

Internal quality control in clinical chemistry laboratories are based on analyzing samples of stable control materials among the patient samples. The control results are interpreted by using quality control rules that usually are designed to detect systematic errors. The best rules have a high probability of error detection (Ped), i.e. to detect the maximal allowable (critical) systematic error and a low probability of false rejection (Pfr, false alarm). In this work we show that quality control rules can be represented by points on a ROC curve which appears when Ped is plotted against Pfr and only the control limit is varied. Further, we introduce a new method for choosing the optimal control limit, analogous to choosing the optimal operating point on the ROC curve of a diagnostic test. This decision needs knowledge of the pretest probability of a critical systematic error, the benefit of detecting it when it occurs and the cost of false alarm. The ROC curve analysis showed that if rules based on N = 2 are used, mean rules outperform Westgard rules because the ROC curve of the mean rules was lying above the ROC curves of the Westgard rules. A mean rule also had a lower maximum expected increase in the number of unacceptable patient results reported during the presence of an out-of-control error condition (Max E(NUF)) than comparable Westgard rules.

Multidimensional Assessment of Sarcopenia and Sarcopenic Obesity in Geriatric Patients: Creatinine/Cystatin C Ratio Performs Better than Sarcopenia Index.

The serum creatinine/cystatin C ratio (CCR) and the sarcopenia index (SI) are novel indicators for sarcopenia, but their accuracy may depend on various confounders. To assess CCR and SI diagnostic accuracy, we studied the clinical and biophysical parameters associated with sarcopenia or sarcopenic obesity. A total of 79 elderly patients (65-99 yrs, 33 females) underwent clinical, anthropometric, body composition, geriatric performance, and blood chemistry evaluation. The CCR and SI accuracy were assessed to identify sarcopenia. Sarcopenia was confirmed in 40.5%, and sarcopenic obesity in 8.9% of the subjects. Sarcopenic patients showed an increased Charlson comorbidity index, cardiovascular disease (CVD) rates and frailty, and decreased physical performance than non-sarcopenic subjects. Patients with sarcopenic obesity had increased body fat and inflammatory markers compared to obese subjects without sarcopenia. Sarcopenia was associated with a decreased CCR and SI. However, when the logistic regression models were adjusted for possible confounders (i.e., age, gender, Charlson comorbidity index, presence of CVD, and frailty score), a significant OR was confirmed for the CCR (OR 0.021, 95% CI 0.00055-0.83) but not for the SI. The AUC for the CCR for sarcopenia discrimination was 0.72. A higher performance was observed in patients without chronic kidney diseases (CKD, AUC 0.83). CCR, more than the SI, is a useful, non-invasive, and cost-effective tool to predict sarcopenia, irrespective of the potential confounders, particularly in subjects without CKD.

Interference of hemoglobin variants with HbA1c measurements by six commonly used HbA1c methods.

Glycated hemoglobin, or hemoglobin A1c (HbA1c), serves as a crucial marker for diagnosing diabetes and monitoring its progression. We aimed to assess the interference posed by common Hb variants on popular HbA1c measurement systems. A total of 63 variant and nonvariant samples with target values assigned by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC)-calibrated methods were included. We assessed 6 methods for measuring HbA1c in the presence of HbS, HbC, HbD, HbE, and fetal hemoglobin (HbF): 2 cation-exchange high-performance liquid chromatography (HPLC) methods (Bio-Rad D-100 and HLC-723 G8), a capillary electrophoresis (CE) method (Sebia Capillarys 3 TERA), an immunoassay (Roche c501), an enzyme assay system (Mindray BS-600M), and a boronate affinity method (Primus Premier Hb9210). The HbA1c results for nonvariant samples from the 6 methods were in good agreement with the IFCC-calibrated method results. The Bio-Rad D-100, Capillarys 3, Mindray BS-600M, Premier Hb9210, and Roche c501 showed no interference from HbS, HbC, HbD, and HbE. Clinically significant interference was observed for the HLC-723 G8 standard mode. Elevated HbF levels caused significant negative biases for all 6 methods, which increased with increasing HbF concentration. Elevated levels of HbF can severely affect HbA1c measurements by borate affinity, immunoassays, and enzyme assays.

#2683 Targeted antibiotic modulation of the gut microbiome ameliorates hypertensive kidney damage

Abstract Background and Aims High blood pressure is associated with measurable inflammation, which precedes and promotes damage to the heart and kidneys. Microbiome-derived metabolites, particularly indole metabolites, modulate inflammation and host physiology, partially through aryl hydrocarbon receptor (AhR) signaling. To better understand the potential of a microbiome-targeting therapeutic approach to achieve organ protection in hypertension, we used narrow-spectrum antibiotics without enteral absorption to specifically deplete gram-negative or -positive bacteria in double transgenic rats (dTGR). Method Four-week-old dTGR (transgenic for human renin and angiotensinogen) were treated with oral Vancomycin (Vanco), Polymyxin B (Poly) or Vehicle (Veh) for 3 weeks. Seven-week-old SD rats were included as healthy controls. Microbiome, clinical and immune phenotype were analyzed by shotgun metagenomic sequencing, echocardiography, telemetric blood pressure (BP) measurement, clinical chemistry, bulk RNAseq and flow cytometry. Results Hypertensive kidney damage was ameliorated in Vanco treated dTGR, as assessed by renal Lcn2 expression, blood urea nitrogen and albuminuria. Vanco treated dTGR had significantly decreased cardiac hypertrophy. Poly treatment showed no effect. BP levels for both antibiotic treatments were not significantly different from Veh, despite a significantly improved endothelium-dependent and -independent vasorelaxation in isolated mesenteric arteries in both treated groups. Surprisingly, Vanco treatment led to a massive increase of gram-positive Lactobacilli and associated gene abundance for the production of indole lactic acid (ILA, via araT). We could previously show that ILA inhibits differentiation of pathological Th17 cells through AhR modulation. In line, Vanco treatment reduced the increased number of pathological Th17 in the kidney and intestine of dTGR. Poly treatment did not alter the inflammatory signature. Conclusion Modulation of the intestinal microbiome by narrow-spectrum antibiotics affects hypertensive organ damage. Our data underscores the importance of the gut microbiome in modulating hypertensive organ damage and helps to identify potential therapeutic strategies in the microbiome. Ongoing experiments investigate pro- and postbiotic therapeutic approaches and their AhR dependency.

Frequency and pattern of test utilization rate in clinical biochemistry laboratory: two different large hospital examples

Abstract Objectives Clinical Biochemistry Laboratories (CBL) are the most frequently utilized laboratory group in healthcare, and their significance in patient care is indisputable. This study investigated the frequency and pattern of test utilization rate in CBL at two large hospitals’ outpatient and inpatient clinics. Methods A total of 43,732,428 CBL tests, including clinical chemistry, immunoassay, coagulation, specific proteins, CBC, and urinalysis, were conducted for 12,182,382 patients across two large hospitals in different settings between 2018 and 2022. These tests were analyzed alongside patient admissions data, with a focus on the distribution across various clinics. Results 94 and 93 % of those admitted to Hospitals 1 and 2 were outpatients. They had applied to CBL laboratories for 27.1–30.3 % of outpatients and 81.2–88.7 % of inpatients for at least one test. When analyzing the rates at which laboratory tests were requested for outpatients, it was found that emergency departments had the highest test-requesting rates, ranging from 19.99 to 45.36 %. This was followed by internal medicine clinics, with rates ranging from 13.77 to 14.8 %, and inpatient intensive care units, with rates between 24.31 and 30.14 %. Outpatients had 10–11 test requests for each patient and 16–31 for inpatients. The most frequently requested laboratory tests were CBC, glucose, creatinine, urea, AST and ALT in two hospitals. Conclusions Despite significant variations in location, structure, medical staff, and patient demographics, approximately one-third of outpatients and 85 % of inpatients at these hospitals undergo testing in CBL. CBLs are essential for screening, diagnosis, prognosis, and healthcare treatment.

Detection of antinuclear antibodies: recommendations from EFLM, EASI and ICAPEFLM Paper

<br><b>Aim:</b> Antinuclear antibodies (ANA) are important for the diagnosis of various autoimmune diseases. ANA are usually detected by indirect immunofluorescence assay (IFA) using HEp-2 cells (HEp-2 IFA). There are many variables influencing HEp-2 IFA results, such as subjective visual reading, serum screening dilution, substrate manufacturing, microscope components and conjugate. Newer developments on ANA testing that offer novel features adopted by some clinical laboratories include automated computer-assisted diagnosis (CAD) systems and solid phase assays (SPA).</br> <br><b>Methods:</b> A group of experts reviewed current literature and established recommendations on methodological aspects of ANA testing. This process was supported by a two round Delphi exercise. International expert groups that participated in this initiative included (i) the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group "Autoimmunity Testing"; (ii) the European Autoimmune Standardization Initiative (EASI); and (iii) the International Consensus on ANA Patterns (ICAP).</br> <br><b>Results:</b> In total, 35 recommendations/statements related to (i) ANA testing and reporting by HEp-2 IFA; (ii) HEp-2 IFA methodological aspects including substrate/conjugate selection and the application of CAD systems; (iii) quality assurance; (iv) HEp-2 IFA validation/verification approaches and (v) SPA were formulated. Globally, 95% of all submitted scores in the final Delphi round were above 6 (moderately agree, agree or strongly agree) and 85% above 7 (agree and strongly agree), indicating strong international support for the proposed recommendations.</br> <br><b>Conclusions:</b> These recommendations are an important step to achieve high quality ANA testing.</br>

Clinical Chemistry and Autoverification: A Path Less Traversed

Clinical Chemistry and Autoverification: A Path Less Traversed

Safety and Efficacy of AlphaWave® L-Theanine Supplementation for 28Days in Healthy Adults with Moderate Stress: A Randomized, Double-Blind, Placebo-Controlled Trial.

Prolonged periods of stress may lead to negative health consequences. AlphaWave® L-Theanine was safe and efficacious during an acute stress challenge. However, double-blind, placebo-controlled clinical trials investigating the longer term effects of L-theanine supplementation on stress are warranted. Thirty healthy adults (18-65years) with moderate stress were randomized to AlphaWave® L-Theanine (400mg L-theanine/day) or placebo (n = 15/group) for 28days. Stress was assessed by salivary cortisol, Perceived Stress Scale (PSS) and Depression, Anxiety and Stress Scale-21; sleep was assessed by the Healthy People Sleep Quality Index and actigraphy device; cognition was assessed by Computerized Mental Performance Assessment System; mood was assessed by Profile of Mood States. All outcomes were measured at baseline, Days 14 and 28. Safety included vital signs, clinical chemistry, haematology and adverse events (AEs). All AEs were resolved by the end of the study period or upon subsequent follow up, and out of range laboratory values and changes in vital signs were deemed not clinically relevant following AlphaWave® L-Theanine supplementation. Participants supplemented with AlphaWave® L-Theanine had decreases of 12.92% (p = 0.051) and 17.98% (p = 0.04) in PSS scores after 14 and 28days, respectively, while those on placebo had respective decreases of 9.74% (p = 0.061) and 17.88% (p = 0.009). There were no significant differences between groups for change in salivary cortisol. The AlphaWave® L-Theanine group demonstrated decreased time asleep after 28days and significantly reduced light sleep after 14 and 28days compared to placebo (p ≤ 0.040). The AlphaWave® L-Theanine group significantly improved by 21.79% and 21.33% in Stroop test correct reaction time after 14 and 28days, respectively, while those on placebo improved after 28days only (p = 0.005). AlphaWave® L-Theanine supplementation for 28days was safe and significantly decreased perceived stress significantly decreased perceived stress and light sleep, improved sleep quality and enhanced cognitive attention in the studied population. Larger, randomized controlled trials with longer duration of AlphaWave® L-Theanine supplementation are warranted to reduce inter-individual variability and the potential placebo effect. ClinicalTrials.gov identifier, NCT05808595.

Preserved seasonal variation in glycemic control in patients with type 2 diabetes mellitus during COVID-19: a 3-year-long retrospective cohort study in older adults in Japan.

The coronavirus disease 2019 (COVID-19) pandemic has changed our lifestyle by imposing restrictions, such as physical distancing. The effect of COVID-19 prevalence on seasonal variations in glycemic control in patients with diabetes mellitus (DM) remains unknown. This single-center retrospective cohort study evaluated glycemic control in patients with type 2 DM who visited Sugi Cardiovascular Hospital in December 2021. We evaluated the clinical findings of all patients treated regularly between March 1, 2019, and December 31, 2021, including the periods both before and after the COVID-19 pandemic. All the standard treatments were approved. Furthermore, seasonal changes in hemoglobin A1c (HbA1c) levels were evaluated using stratified analyses based on age. This study analyzed 86 patients (mean age, 69.6 ± 9.2years; men, 57). Median HbA1c (National Glycohemoglobin Standardization Program [Union of Clinical Chemistry]) levels in spring (March) were 7.70% (interquartile range (IQR):7.23%-8.30%) [60.6mmol/mol (IQR:55.4-67.2mmol/mol)], 7.35% (IQR:6.90%-7.90%) [56.8mmol/mol (IQR:51.9-62.8mmol/mol)], and 7.50% (IQR:7.10%-8.00%) [58.5mmol/mol (IQR:54.1-63.9mmol/mol)] in 2019, 2020, and 2021, respectively. During these periods, HbA1c levels and body mass index (BMI) revealed significant seasonal variations "high in spring" and "low in autumn." Median HbA1c levels in spring (March) and autumn (September) were 7.86% [61.2 mmol/mol] and 7.48% [57.4 mmol/mol] in 2019 (P < 0.001), 7.50% [57.7 mmol/mol] and 7.17% [54.2 mmol/mol] in 2020 (P < 0.001), and 7.61% [58.3 mmol/mol] and 7.19% [53.8 mmol/mol] in 2021 (P < 0.001). Seasonal variations in HbA1c levels and BMI were maintained over the past 3years, including the pandemic period. None of the patients in this study developed COVID-19 during the study period. Seasonal variations in glycemic control in patients with DM were not influenced by lifestyle modifications associated with COVID-19. Maintenance of physical activity is necessary to prevent the development of sarcopenia. Moreover, seasonal variations in glycemic metabolism should be considered an independent factor for DM management. Additional extensive multifacility investigations are necessary to corroborate our findings.

Design of an Insulin Tracer Protein-Based Biosensor for Insulin Determination

Aim: The regulation of blood glucose levels is controlled by insulin, which is produced by the pancreatic beta system. Inadequate synthesis of beta insulin, results in elevated glucose levels, a condition known as diabetes, which can lead to various chronic health issues. In recent times, the diagnosis of diabetes, particularly type 1, has shifted towards the direct measurement of insulin levels. To facilitate this, an immunosensor was created to enable rapid and sensitive examination of insulin levels, with the goal of improving the quality for life for diabetic patients. Material and Method: For this purpose, an insulin tracer protein based biosensor was designed for the determination of insulin at all solutions. For determination of insulin, electrobiochemical analyses were performed. Optimisation and characterisation studies were performed using differential pulse voltammetry. The performance of bioelectrochemical system was analysed by Receiver Operating Characteristic method. Results: The insulin biosensor cyclic woltammogram was obtained between -0,1 and 0,6 V potantial. At 0,45 V was found as the anodic peak side for determination the insulin. Optimisation and characterisation studies performed at 0,45 V with differential pulse voltammetry. Conclusion: The study successfully identified stable and easy-to-use insulin concentrations, indicating the potential of the newly developed immunosensor for applications in clinical biochemistry laboratories.

Biochemical Significance of Matrix Gla Protein and Its Potential Use as a Marker in Clinical Biochemistry

The aim of this work was to present an overview on the biochemical significance of the matrix γ‑carboxyglutamate (Gla) protein (MGP). According to the literature, the MGP is associated with vascular, bone, and kidney metabolisms, as well asvitamin K levels. The relationship of MGP to Keutel's syndrome, Pseudoxanthoma elasticum, colitis, and dental calculus is described. The information published so far suggests that MGP protein levels could have potential as a biochemical marker in these serious diseases.

Plant-Derived Coumarins: A Narrative Review of Their Structural and Biomedical Diversity.

Plant-derived coumarin (PDC) is a naturally occurring heterocyclic backbone that belongs to the benzopyrone family. PDC and its based products are characterized by low toxicity and high distribution in a variety of herbal treatments that have numerous therapeutic potentials. These include anticoagulants, antibacterials, anti-inflammatory agents, anticancer agents, antioxidants, and others. So, it may be appropriate to investigate the qualities and potential bioactivities of PDCs. This article provides an overview of the biomedical potentials, availability, and clinical use possibilities of PDCs, with a focus on their important modes of action, using information on various pharmacological qualities discovered. The data used in this study came from published research between 2015 and 2023. We reviewed a selection of databases, including PubMed, Scopus, Web of Science, and Google Scholar, during that period. In conclusion, because of their abundance in medicinal plants, the clinical biochemistry attributes of PDCs are currently of interest. In a variety of medical specialties, PDCs serve a useful role as therapeutic agents.

Feasibility of hemoperfusion using extracorporeal therapy in the horse.

Develop, implement, and monitor for adverse effects of, a novel hemoperfusion therapy in adult horses. A prospective, observational feasibility study using three healthy adult horses from the North Carolina State University teaching herd. Health status was determined by physical exam, complete blood count, coagulation panel, and serum biochemistry. Each horse was instrumented with a 14 Fr × 25 cm double-lumen temporary hemodialysis catheter and underwent a 240 min polymer-based hemoperfusion session. Horses were administered unfractionated heparin to maintain anti-coagulation during the session. Given the novelty of this therapy in horses, each horse was treated as a learning opportunity that informed an iterative process of protocol development and modification. Our long-term goal is to investigate potential clinical applications of hemoperfusion in horses, including cytokine reduction in horses with severe SIRS/sepsis. Horses were monitored for changes in clinical exam, biochemistry and hematology parameters. Additionally, cytokines were quantified to determine whether extracorporeal hemadsorption therapy alone caused an inflammatory response. Our results show that hemoperfusion therapy was associated with decreased platelet counts and serum albumin concentration. There was no significant change in plasma cytokine concentrations with hemoperfusion therapy. In one horse, the cytokine concentrations decreased, as previously reported with hemoperfusion therapy in humans. We hypothesized that hemoperfusion therapy could be performed in healthy adult horses without significant adverse effects. Polymer-based hemoperfusion is a feasible extracorporeal therapy (ECT) modality for adult horses. Additional studies are needed to further establish clinical protocols, as well as establish efficacy of polymer-based hemoperfusion for treatment of various conditions in horses, including intoxications, immune-mediated conditions, and sepsis.

Defining Trimester-Specific Reference Intervals for Thyroid Hormones: Insights from a Bulgarian Monocenter Study.

Background and Objectives: Pregnancy introduces various interfering factors that, alongside individual variations, impact the assessment of thyroid function tests. This underscores the necessity of defining trimester-specific reference intervals for thyroid-stimulating hormone (TSH) levels. Differences in population characteristics, including ethnicity, socio-economic factors, iodine prophylaxis, and obesity, emphasize the need to establish trimester-specific TSH ranges for women of reproductive age in the respective region or center. The aim of the present study was to establish first- and second-trimester-specific reference intervals for TSH and free thyroxine (FT4) in a relevant pregnant population. Materials and Methods: A retrospective monocenter analysis utilized the electronic database of Ob/Gyn Hospital "Dr. Shterev", Sofia, Bulgaria. The analysis involved data from 497 pregnant and 250 non-pregnant women, all without evidence of thyroid dysfunction or a family history thereof, no indication of taking medication interfering with thyroid function, no evidence of levothyroxine treatment, and no history of sterility treatment. To establish the limits of the TSH reference range, the percentile method was applied using a bootstrapping procedure following the recommendations of the International Federation of Clinical Chemistry (IFCC). Results: Trimester-specific reference intervals for TSH and FT4 in our center were established as follows: first trimester-0.38-2.91 mU/L, FT4-12.18-19.48 pmol/L; second trimester-0.72-4.22 mIU/L and 9.64-17.39 pmol/L, respectively. We also established the normal reference range for the non-pregnant control group, which is similar to that applicable in our laboratory. Conclusions: Our results differ from the fixed limits recommended by the American Thyroid Association, European Thyroid Association, and Endocrine Society Guidelines. Following the relevant established intervals would significantly impact timely diagnosis and therapy requirements for a substantial proportion of pregnant women.

Assessing Non-Laboratory Healthcare Professionals' Attitude towards the Importance of Patient Preparation for Laboratory Tests.

(1) Background: Various guidelines address patient preparation and its importance for venous blood sampling, such as the GP41 guideline issued by the Clinical Laboratory Standards Institute (CLSI) and the blood collection guidelines published by the World Health Organisation. Recommendations provided by national societies or international organisations in the field of radiology, such as The Contrast Media Safety Committee of the European Society of Urogenital Radiology, or in the field of laboratory medicine, such as the Working Group for Preanalytical Phase (WG-PRE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) and the Latin American Working Group for Preanalytical Phase (WG-PRE-LATAM) of the Latin American Confederation of Clinical Biochemistry (COLABIOCLI), also guide this practice. There is a notable lack of understanding regarding the viewpoints held by non-laboratory healthcare professionals concerning the significance of patient preparation for laboratory testing and the impact of typical factors associated with patient preparation. This study endeavours to bridge this gap by assessing the attitude of non-laboratory healthcare professionals in Lithuania regarding these pivotal aspects. (2) Methods: A self-designed anonymous questionnaire was disseminated among 141 public healthcare institutions in Lithuania. The internal consistency of the questionnaire was evaluated by computing Cronbach's alpha. Descriptive statistics were utilised for the variables, while comparisons of attitude among groups were conducted using Mann-Whitney U (for two groups) or Kruskal-Wallis (for more than two groups) for categorical and discrete indicators. The Kruskal-Wallis post-hoc test was employed for pairwise comparisons. A significance level of p-Value < 0.05 was applied to establish statistical significance. (3) Results: A total of 158 respondents constituted two distinct groups of healthcare professionals: nurses and physicians. Most of the participants either agreed or strongly agreed that patient preparation could introduce bias into laboratory test results. Professionals with less than 20 years of work experience or those who attended training in patient preparation for sampling within a 5-year timeframe exhibited stronger agreement regarding different preanalytical factors in patient preparation and their impact on laboratory test results compared to their counterparts. (4) Conclusions: Non-laboratory healthcare professionals who participated in this survey consider proper patient preparation for laboratory testing to be a significant step towards obtaining accurate test results. They also recognize the commonly acknowledged preanalytical factors as important for ensuring reliable test results. However, attitudes towards the importance of several preanalytical factors vary depending on whether non-laboratory healthcare professionals have more or less than 20 years of work experience, as well as whether they have attended any training on this topic within the last five years or have never attended such training.

Comparison of the clinical chemistry score to other biomarker algorithms for rapid rule-out of acute myocardial infarction and risk stratification

Abstract Funding Acknowledgements None. Background The clinical chemistry score (CCS) comprising high-sensitivity (hs) cardiac troponins (cTn), glucose and estimated glomerular filtration rate has been previously validated with superior accuracy for detection and risk stratification of acute myocardial infarction (AMI) compared to hs-cTn alone. Methods The CCS was directly compared to other biomarker-based algorithms for rapid rule-out and prognostication of AMI including the hs-cTnT limit-of-blank (LOB, &amp;lt;3 ng/L) or limit-of-detection (LOD, &amp;lt;5 ng/L) and the dual marker strategy (DMS) (copeptin &amp;lt;10 pmol/L and hs-cTnT ≤14 ng/L) in 1506 patients presenting to the emergency department (ED) with symptoms suggestive of acute coronary syndrome. Negative predictive values (NPV) and sensitivities for rule-out of AMI were assessed and outcomes included rates of the combined end-point of all-cause mortality, myocardial re-infarction and stroke within 12 months. Results NPVs of 100% (98.3-100%) could be found for a CCS=0, hs-cTnT LoB and hs-cTnT LoD with rule-out efficacies of 11.1%, 7.6% and 18.3% as well as specificities of 13.0% (9.9-16.6%), 8.8% (7.3-10.5%) and 21.4% (19.2-23.8%), respectively. A CCS≤ 1 achieved a rule-out in 32.2% of all patients with a NPV of 99.6% (98.4-99.9%) and specificity of 37.4% (34.2-40.5%) compared to a rule-out efficacy of 51.2%, NPV of 99.0 (98.0-99.5) and specificity of 59.7% (57.0-62.4%) for the DMS. Rates of the combined end-point of death/AMI within 30 days ranged between 0.0% and 0.5% for all fast-rule-out protocols. Conclusions The CCS enables a reliable rule-out of AMI with low outcome rates in short and long-term follow-up for a specific population of ED patients. However, compared to a single or dual biomarker strategy, the CCS rule-out is attenuated by a loss of specificity and lower efficacy. Thus, the clinical benefit of the CCS in clinical practice seems to be negligible.