Publications by authors named "Alen Vrtaric"

Objectives: Autoverification increases the efficiency of laboratories. Laboratories accredited according to ISO 15189:2022 need to validate their processes, including autoverification, and assess the associated risks to patient safety. The aim of this study was to propose a systematic verification algorithm for autoverification and to assess its potential risks.

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Introduction: Reliable and accurate measurement of blood glucose concentration is of crucial importance for making clinical decisions in diagnosis diabetes, gestational diabetes and impaired fasting glucose tolerance.

Materials And Methods: Survey was performed in form of questionnaire. Questionnaire was sent to all Croatian laboratories (N = 204) in electronic form using SurveyMonkey cloud-based software (SurveyMonkey, Inc.

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Article Synopsis
  • - This study investigated how increasing bilirubin levels affect 34 clinical chemistry tests across four different analytical platforms, positing that interference varies by both method and analyzer.
  • - Researchers prepared serum samples spiked with bilirubin and measured analyte values simultaneously at all locations, analyzing the data for consistency and potential bias.
  • - Results showed that while some interferences from bilirubin were consistent, others differed depending on the specific analyzer, suggesting variability in how different platforms handle icterus interference.
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Chronic spontaneous urticaria (CSU) is a dermatological disorder accompanied by itching that greatly affects the quality of life and quality of sleep. Therefore, it is assumed that CSU patients consequently experience reduced melatonin secretion and lower values of serum or salivary melatonin. This pilot study included 20 patients with CSU (chronic urticaria of unknown etiology that lasts for more than 6 weeks) and 10 healthy controls.

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Objective: To investigate the association of immune response with vaccination adverse effects at peak anti-receptor-binding domain spike subunit 1 (anti-RBDS1) IgG after full vaccination with Comirnaty, Spikevax, or Vaxzevria.

Methods: Anti-RBDS1 IgG concentrations after vaccination were determined in healthy adults vaccinated with the Comirnaty, Spikevax, and Vaxzevria vaccines. The association of reactogenicity and peak antibody response after vaccination was tested.

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Melatonin is the main hormone that regulates the sleep cycle, and it is mostly produced by the pineal gland from the amino acid tryptophan. It has cytoprotective, immunomodulatory, and anti-apoptotic effects. Melatonin is also one of the most powerful natural antioxidants, directly acting on free radicals and the intracellular antioxidant enzyme system.

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High prevalence and mortality of prostate cancer (PCa) are well known global health issues. Novel biomarkers for better identifying patients with PCa are the subject of extensive research. Prostate specific antigen (PSA) shows low specificity in screening and diagnostics, leading to unnecessary biopsies and health costs.

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Objectives: To determine the differences between pediatric patients with eating disorders (ED) and the control group in the amount of saliva and the concentration of total amylase and electrolytes in saliva, and to evaluate the correlation between the saliva changes and nutritional status.

Material And Methods: The study included 101 participants (14.34 ±1.

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Article Synopsis
  • - The study aimed to assess how various hemolysis methods affect test results across three different analyzers, focusing on the impact of hemolysis on biochemistry parameters.
  • - Four hemolysis methods were tested: adding pure hemoglobin, causing osmotic shock, aspiration through a needle, and freezing/thawing blood; results indicated that hemolysis significantly affected certain analytes like potassium and lactate dehydrogenase.
  • - The findings concluded that different analyzers respond uniquely to hemolysis, with the aspiration method being the most sensitive to interference, whereas adding free hemoglobin showed the least impact on test results.
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Seminoma (SE) is the most frequent type of testicular tumour, affecting predominantly young men. Early detection and diagnosis of SE could significantly improve life quality and reproductive health after diagnosis and treatment. Copy number variation (CNV) has already been associated with various cancers as well as SE.

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Prostate cancer (PC) is the most common malignancy in men. Common characteristic involved in PC pathogenesis are disturbed lipid metabolism and abnormal cholesterol accumulation. Cholesterol can be further utilized for membrane or hormone synthesis while cholesterol biosynthesis intermediates are important for oncogene membrane anchoring, nucleotide synthesis and mitochondrial electron transport.

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While tissue biopsy has for the longest time been the gold-standard in biomedicine, precision/personalized medicine is making the shift toward liquid biopsies. Cell-free DNA (cfDNA) based genetic and epigenetic biomarkers reflect the molecular status of its tissue-of-origin allowing for early and non-invasive diagnostics of different pathologies. However, selection of preanalytical procedures (including cfDNA isolation) as well as analytical methods are known to impact the downstream results.

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Prostate cancer (PCa) is the most commonly diagnosed neoplasm among men. Since it often resembles benign prostate hyperplasia (BPH), biomarkers with a higher differential value than PSA are required. Epigenetic biomarkers in liquid biopsies, especially miRNA, could address this challenge.

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Within the last several years, frequency of vitamin D testing has multiplied substantially all over the world, since it has been shown to have an important role in many diseases and conditions. Even though liquid chromatography - tandem mass spectrometry (LC-MS/MS) has been identified as "gold standard" method for vitamin D measurement, most laboratories still use immunochemistry methods. Besides analytical problems (hydrophobicity, low circulating concentrations, ability to bind to lipids, albumins and vitamin D binding protein, presence of multiple vitamin D metabolites and variable ratios of 25(OH)D and 25(OH)D in the blood), vitamin D shows great preanalytical variability, since its concentration is drastically influenced by seasonal changes, exposure to sun, type of clothes or sun block creams.

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Vitamin D is beneficial in patients with immune-mediated rheumatic diseases as it has been shown that it lowers the incidence risk and the level of inflammation. To examine the association between clinical outcomes and initial 25-hydroxyvitamin D [25(OH)D] concentrations in patients with the immune-mediated rheumatic diseases treated with infliximab for 9 months. This study was performed in patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) treated with infliximab for at least 38 weeks.

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Introduction: Our aim was to investigate the stability of clinically relevant analytes in pleural and peritoneal fluids stored in variable time periods and variable storage temperatures prior to analysis.

Materials And Methods: Baseline total proteins (TP), albumin (ALB), lactate dehydrogenase (LD), cholesterol (CHOL), triglycerides (TRIG), creatinine (CREA), urea, glucose and amylase (AMY) were measured using standard methods in residual samples from 29 pleural and 12 peritoneal fluids referred to our laboratory. Aliquots were stored for 6 hours at room temperature (RT); 3, 7, 14 and 30 days at - 20°C.

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Background Serum samples should be centrifuged for at least 10 min at 1300-2500 × g. Changed centrifugation conditions could compromise sample quality. The objective of this study was to compare the serum quality and turnaround time (TAT) using different centrifugation conditions.

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Background Nowadays over-the-counter (OTC) drugs and dietary supplements are widely used. Their use can have a significant impact on the validity of laboratory results. The aim of this multicenter European study was to determine the frequency of consumption of various dietary products and OTC drugs among patients and explore their level of knowledge and awareness about the potential impact of various products on laboratory test results.

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Background: The aim of our study was to perform verification of serum indices on three clinical chemistry platforms.

Methods: This study was done on three analyzers: Abbott Architect c8000, Beckman Coulter AU5800 (BC) and Roche Cobas 6000 c501. The following analytical specifications were verified: precision (two patient samples), accuracy (sample with the highest concentration of interferent was serially diluted and measured values compared to theoretical values), comparability (120 patients samples) and cross reactivity (samples with increasing concentrations of interferent were divided in two aliquots and remaining interferents were added in each aliquot.

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Objective: To determine whether K2-ethylenediaminetetraacetic acid (EDTA) and K3-EDTA Greiner tubes could be used interchangeably for glycosylated hemoglobin, type A1C (HbA1c) measurement via the Abbott Laboratories ARCHITECT chemiluminescent microparticle HbA1c assay on the ARCHITECT i2000SR immunoanalyzer at our university hospital.

Materials: We drew blood from a total of 45 outpatients into plastic Greiner Vacuette tubes, some of which were lined with K2-EDTA and others with K3-EDTA anticoagulant. Data are presented as median and interquartile range values.

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Background: Endogenous interferences are an important source of biased laboratory results. Hemolysis, lipemia and icteria are the main source of endogenous interference in laboratory medicine. Accreditation according to ISO 15189 improves the overall quality of the laboratory procedures.

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