UNASSIGNED: The pre-analytical (PA) phase is the most vulnerable phase of the laboratory testing procedure, with critical procedures-collection, handling, sample transport, and time and temperature of sample storage. This study aimed to examine the stability of basic biochemical parameters depending on the samples\' storage conditions and the number of freeze-thaw cycles (FTCs). In parallel, the presence of sample bacterial contamination during routine laboratory work was examined.
UNASSIGNED: Two plasma pools (ethylenediaminetetraacetic acid (EDTA), and sodium-fluoride/potassium oxalate plasma (NaF)) were stored at +4 ˚C/-20 ˚C. Total chole - sterol (TC), glucose, triglycerides (TG), urea, and albumin concentrations were measured using BioSystems reagents (cholesterol oxidase/peroxidase, glucose oxidase/per - oxidase, glycerol phosphate oxidase/peroxidase, urease/ salicylate, and bromcresol green method, respectively) on Ilab 300+. Sample bacterial contamination was determined by 16S rRNA sequence analysis. The expe - riment encompassed a 5 day-period: Day 1-fresh sample, Day 2-1st FTC, Day 3-2nd FTC, Day 4-3rd FTC, Day 5-4th FTC. The appearance of bacteria in two consecutive samples was the experiment\'s endpoint.
UNASSIGNED: Preanalitička (PA) faza je složen proces koji čine: prikupljanje, rukovanje, transport i skladištenje uzoraka, i predstavlja najznačajniji izvor laboratorijskih grešaka. Cilj ovog istraživanja je bio da se ispita stabilnost osnovnih biohemijskih parametara u zavisnosti od uslova skladištenja uzoraka i broja ciklusa zamrzavanja-odmrzavanja (FTC). Pored toga, ispitivano je prisustvo bakterijske kontaminacije uzoraka tokom rutinskog laboratorijskog rada.
UNASSIGNED: Dva \"pool\"-a plazme (etilendiaminotetrasirćetna kiselina (EDTA) i natrijum-fluorid/kalijum oksalat (NaF)) su skladištena na +4 ˚C/-20 ˚C. Koncentracije ukupnog hole sterola (TC), glukoze, triglicerida (TG), uree i albumina su određene korišćenjem BioSystems reagenasa (holesterol oksi daza/peroksidaza, glukoza oksidaza/peroksidaza, glice rol fosfat oksidaza/peroksidaza, ureaza/salicilat, od - nosno bromkrezol zeleno metodama, sukcesivno) na Ilab 300+ analizatoru. Bakterijska kontaminacija uzoraka je potvrđena 16S rRNA sekvencioniranjem. Eksperiment je sproveden tokom 5 uzastopnih dana: 1. dan - svež uzorak, 2. dan - 1. FTC, 3. dan -2. FTC, 4. dan - 3. FTC, 5. dan - 4. FTC. Završnu tačku eksperimenta predstavljala je pojava bakterija u dva uzastopna uzorka.
UNASSIGNED: Tokom 4 FTC koncentracije uree u plazmi se nisu značajno razlikovale. Koncentracija glukoze je bila stabilna u EDTA +4 ˚C i NaF -20 ˚C do 3.FTC (P=0,008, P=0,042, redom). Koncentracije TG su se značajno pro - menile u uzorku EDTA -20 ˚C nakon 1. i 4. FTC-a (P=0,022, P=0,010, redom). U uzorcima NaF plazme nije došlo do bakterijske kontaminacije tokom 4. FTC.
UNASSIGNED: Koncentracije uree i glukoze su bile stabilne tokom trajanja eksperimenta. Promene u koncentracijama lipida nakon FTC prate složene obrasce. Rast bakterija nije primećen u uzorcima NaF plazme, te upotreba ovog anti-koagulansa može biti opravdana u analitičkim procedurama podložnim uticaju mikrobiološke kontaminacije.

BACKGROUND: The Parasitology-Mycology Laboratory\'s analytical process involves three stages: pre-analytical, analytical, and post-analytical. Our focus is on the pre-analytical phase (PAP). This study addresses managing PAP non-conformities at Mohammed VI University Hospital in Oujda, aligning with quality standards like ISO 15189 and GBEA and aiming to detect and resolve deviations.
METHODS: This 84-month retrospective study analyzed specimens at the Parasitology-Mycology lab in the Mohammed VI University Hospital in Oujda. Examination requests were made through the hospital\'s IT system (HOSIX), and samples were transported pneumatically. After administrative and technical checks, samples were rejected, processed, or retained for correction based on findings. Reports of non-conformities were sent to prescribers via the IT system. Data were analyzed and flowcharts were created using Microsoft Excel (Redmond, USA).
CONCLUSIONS: During the study period, prescription errors were the most common non-conformities (65.88%; n=56), followed by sample nature errors (29.41%; n=25) and sample packaging errors (4.70%; n=4). Prescription discrepancies, mycological exams for patients on antifungal treatment or carrying Henna, and missing clinical information were the main causes. Outpatient samples accounted for 29.41% of non-conformities, while inpatient samples accounted for 70.59%. The majority of inpatient non-conformities came from the dermatology department (n=42; 49.41%). The pre-analytical phase in Parasitology-Mycology is crucial for ensuring accurate results, involving the coordination of various stages such as staff training, documentation, and non-conformity management. Prescription errors were predominant among non-conformities, followed by sample nature and packaging errors. Outpatient samples had fewer non-conformities compared to inpatient ones, possibly due to supervision by a biologist. Non-conformities lead to therapeutic, prognostic, and economic issues, underscoring the need for their reduction. Corrective actions are crucial, along with establishing policies for error detection and control. Potential causes of non-conformities can be analyzed using methods like the 5M approach. Suggestions for improvement include distributing a validated sampling manual, creating electronic test request forms, staff training, ongoing training programs, and regular meetings for information exchange.
CONCLUSIONS: The pre-analytical phase in Parasitology-Mycology is crucial, demanding a quality-focused approach for strict adherence to procedures and traceability. Mastery of this phase ensures result reliability.

OBJECTIVE: Since 2023, guidelines of the AACC/ADA recommend the use of citrate buffer-containing tubes as a first option for glucose measurement. This study aims to assess the pre-analytical stability of glucose under various conditions (room temperature (RT) or at 4 °C) and the potential real-world impact of introducing these tubes on (gestational) diabetes and IFG prevalence.
METHODS: 25 healthy volunteers were sampled to assess glucose stability across time, at 4 °C and at RT, before and following centrifugation. 701 patients undergoing fasting plasma glucose analysis and 109 women having OGTT were collected according to current procedures (NaFl K2C2O4 (NaFl) tubes) as well as with citrate-containing tubes (FC Mix).
RESULTS: The mean glucose concentration bias between FC Mix and NaFl tubes when centrifugation occurred within 5 min was 0.53 % and this difference raised slowly to reach 2.3 %, six-hours post-centrifugation. When centrifugation was delayed, a rapid decrease in glucose concentrations was observed for NaFl tubes (4.9 % at 30 min) and this trend was only partially reduced by placing samples at 4 °C (3.1 %). The decrease reached 10.8 % (RT) and 7.8 % (4 °C) at 2 h, before reaching a plateau. Samples collected on citrate remained stable during 24 h. In real-life conditions, the mean bias between FC Mix and NaFl tubes increased progressively over time and reached 8.59 % for samples centrifuged between two- and four-hours following sampling. Compared to widespread practices, the use of citrate-containing tubes increased IFG, DM and GDM prevalences by 84.0 %, 36.7 % and 150 %, respectively.
CONCLUSIONS: Glucose concentrations rapidly decrease in NaFl tubes following collection and placing samples at 4 °C reduces only marginally the decay. Citrate-containing tubes offer a valuable solution for direct and long-lasting glucose stabilization but, before wider adoption, large epidemiologic studies should confirm or redefine current diabetes diagnostic thresholds.

The harmonization of laboratory biomarkers is pivotal in ensuring consistent and reliable diagnostic outcomes across different clinical settings. This systematic review examines the harmonization of C-Reactive Protein (CRP) and N-Terminal Prohormone of Brain Natriuretic Peptide (NT-proBNP) measurements, both of which are jointly utilized in the diagnosis and management of cardiovascular diseases. To identify relevant studies, we searched the PubMed electronic database using specific medical subject headings and keywords such as C-Reactive Protein, CRP, high sensitivity C-Reactive Protein (hs-CRP), N-terminal pro B-type natriuretic peptide, and NT-proBNP, focusing on publications from June 1 to September 26, 2021. The query filtered studies to include only those in English involving human subjects. From our search, 97 articles met the inclusion criteria and were included for in-depth analysis. Despite their widespread use, significant variability remains in the measurements of CRP and NT-proBNP due to a lack of standardized pre-analytical, analytical, and post-analytical practices. This review highlights the consequences of this variability on clinical decision-making and patient outcomes and emphasizes the need for international standards and guidelines to achieve better harmonization. Our findings advocate for the establishment of universal protocols to enhance the reliability of these biomarker measurements across different clinical environments, ensuring improved healthcare delivery.

OBJECTIVE: Biological variation is a relevant component of diagnostic uncertainty. In addition to within-subject and between-subject variation, preanalytical variation also includes components that contribute to biological variability. Among these, daily recurring, i.e., diurnal physiological variation is of particular importance, as it contains both a random and a non-random component if the exact time of blood collection is not known.
METHODS: We introduce four time-dependent characteristics (TDC) of diurnal variations for measurands to assess the relevance and extent of time dependence on the evaluation of laboratory results.
RESULTS: TDC address (i) a threshold for considering diurnality, (ii) the expected relative changes per time unit, (iii) the permissible time interval between two blood collections at different daytimes within which the expected time dependence does not exceed a defined analytical uncertainty, and (iv) a rhythm-expanded reference change value. TDC and their importance will be exemplified by the measurands aspartate aminotransferase, creatine kinase, glucose, thyroid stimulating hormone, and total bilirubin. TDCs are calculated for four time slots that reflect known blood collection schedules, i.e., 07:00-09:00, 08:00-12:00, 06:00-18:00, and 00:00-24:00. The amplitude and the temporal location of the acrophase are major determinates impacting the diagnostic uncertainty and thus the medical interpretation, especially within the typical blood collection time from 07:00 to 09:00.
CONCLUSIONS: We propose to check measurands for the existence of diurnal variations and, if applicable, to specify their time-dependent characteristics as outlined in our concept.

暂无摘要。

Microribonucleic acids (miRNAs) have emerged as a new category of biomarkers for many human diseases like cancer, cardiovascular and neurodegenerative disorders. MicroRNAs can be detected in various body fluids including blood, urine and cerebrospinal fluid. However, the literature contains conflicting results for circulating miRNAs, which is the main barrier to using miRNAs as non-invasive biomarkers. This variability in results is largely due to differences between studies in sample processing methodology, miRNA quantification and result normalization. The purpose of this review is to describe the various preanalytical, analytical and postanalytical factors that can impact miRNA detection accuracy and to propose recommendations for the standardization of circulating miRNAs measurement.

UNASSIGNED: It is important to accurately determine the blood ethanol concentration (BEC) to ensure appropriate diagnosis and treatment of patients in the emergency department (ED) and protect their legal rights. This study aimed to determine whether sterilization of venipuncture site with ethanol, which is frequently used in practice in the ED would affect BEC.
UNASSIGNED: Venous blood samples were collected by two consecutive techniques from 94 individuals who were admitted to the ED, had an indication for BEC measurement, and volunteered to participate in the study. The reference technique involved applying 3 cc of 10 % povidone-iodine solution to a gauze pad, cleaning the right arm antecubital region, and performing phlebotomy. The index technique used 3 cc of alcohol-based antiseptic (89 % ethanol) on another gauze for cleaning the left arm antecubital region. Both techniques allowed the antiseptic to air-dry for 30 s before phlebotomy. Two blood sample tubes per patient were sent to the laboratory, and BEC were measured using the alcohol dehydrogenase enzymatic method.
UNASSIGNED: 94 patients were included in the study. The mean age was 37.8 years (±15.7), with 77 % (n = 72) of them were male. The median BEC levels measured by both the reference and index techniques were 2 mg/dL (IQR: 0.97-16.25) and 2 mg/dL (IQR: 0.90-15.22), respectively, with no significant statistical difference (p = 0.536). 72 (77 %) of the patients had a BEC level below the legal driving limit of 20 mg/dL. Bland-Altman analysis, performed on these patients, revealed a small negative bias, -0.116 mg/dL with a standard deviation of 1.13 mg/dL. The upper and lower limit of the agreement was 2.092 and -2.323 respectively.
UNASSIGNED: In patients with a BEC level of less than 20 mg/dL, using ethanol-containing antiseptics before blood sampling does not lead to erroneously elevated BEC levels.

OBJECTIVE: It has been recognized that shortened activated partial thromboplastin time (aPTT) may be caused by various preanalytical conditions. As coagulation Factor VIII is included in the in vitro intrinsic coagulation cascade measured by aPTT, we hypothesized that the shortened aPTT could be a result of elevated FVIII activity. We aimed to inspect the connection of elevated FVIII with shortened aPTT, and the possible effect inflammation has on routine laboratory parameters.
METHODS: 40 patients from various hospital departments with aPTT measurement below the lower limit of the reference interval (<23.0 s) were included in the study. To compare the obtained results with aPTT measurements in the non-inflammatory state, samples from 25 volunteers (laboratory personnel) were collected. White blood cell count, C-reactive protein, aPTT, and FVIII values were measured in the control group.
RESULTS: Only two samples among 40 patients with shortened aPTT (5 %) were clotted. Out of the remaining 38, 26 had FVIII activity above 150 % (upper limit of a reference interval), median value of 194 % (IQR: 143-243 %). Seven samples in the control group had shortened aPTT results (36 %). However, all coagulation samples were clot and hemolysis-free. Multiple regression identified only FVIII activity as an independent variable in predicting aPTT values (p=0.001).
CONCLUSIONS: Our results support the thesis that shortened aPTT is rarely a consequence of preanalytical problems. Elevated FVIII activity causes shortened aPTT, not only in the inflammatory state but also in individuals with concentration of inflammatory markers within reference intervals.

OBJECTIVE: Blood Sampling Guidelines have been developed to target European emergency medicine-related professionals involved in the blood sampling process (e.g. physicians, nurses, phlebotomists working in the ED), as well as laboratory physicians and other related professionals. The guidelines population focus on adult patients. The development of these blood sampling guidelines for the ED setting is based on the collaboration of three European scientific societies that have a role to play in the preanalytical phase process: EuSEN, EFLM, and EUSEM. The elaboration of the questions was done using the PICO procedure, literature search and appraisal was based on the GRADE methodology. The final recommendations were reviewed by an international multidisciplinary external review group.
RESULTS: The document includes the elaborated recommendations for the selected sixteen questions. Three in pre-sampling, eight regarding sampling, three post-sampling, and two focus on quality assurance. In general, the quality of the evidence is very low, and the strength of the recommendation in all the questions has been rated as weak. The working group in four questions elaborate the recommendations, based mainly on group experience, rating as good practice.
CONCLUSIONS: The multidisciplinary working group was considered one of the major contributors to this guideline. The lack of quality information highlights the need for research in this area of the patient care process. The peculiarities of the emergency medical areas need specific considerations to minimise the possibility of errors in the preanalytical phase.