Blood sample quality

Clinical Application of ISO and CEN/TS Standards for Liquid Biopsies-Information Everybody Wants but Nobody Wants to Pay For

BACKGROUND

Liquid biopsies are emerging as valuable clinical biomarkers for cancer monitoring. Although International Organization for Standards (ISO) and Technical Specifications from the European Committee for Standardization (CEN/TS) standardized workflows exist, their implementation in clinical practice is underdeveloped. We aimed to assess the applicability of ISO and CEN/TS standards in a real-world clinical setting, with a particular focus on evaluating the impact of preanalytical parameters and hemolysis on liquid biopsy analysis.

METHODS

We evaluated 659 peripheral blood samples from advanced prostate cancer patients against ISO and CEN/TS standards and documented all essential criteria, including tube draw order, filling level, temperature, and time tracking from blood draw to storage. We assessed hemolysis and its effect on circulating tumor DNA (ctDNA) and circulating tumor cell (CTC) analysis.

RESULTS

Our results demonstrated a high compliance rate, with 96.2% (634/659) of samples meeting essential ISO and CEN/TS criteria. We did not observe a significant impact on ctDNA or CTC detection rates between hemolytic and nonhemolytic samples. Hemolysis was identified in 12.9% (40/311) of plasma samples from our advanced prostate cancer cohort, and within the draw order of 5 blood collection tubes, hemolysis did not significantly increase from tube 1 to 5. In total, 83.8% (552/659) of blood collection tubes had high fill levels above 80% of nominal filling level.

CONCLUSIONS

Our study demonstrates the feasibility and benefits of adhering to ISO and CEN/TS standards in a clinical liquid biopsy study. The standards revealed that hemolysis occurred frequently but did not impair downstream ctDNA and CTC analysis in our cohort of advanced prostate cancer patients.

Consistency analysis of two fingertip capillary blood sampling methods for complete blood count

This study was performed to analyze fingertip capillary blood sampling in pediatric patients using microcapillary blood collection tubes and microhematocrit tubes and to compare the blood cell analysis results obtained via these two blood collection methods. Finger capillary blood was collected from 110 outpatients using microcapillary blood collection tubes and microhematocrit tubes and complete blood count analysis was performed with a Sysmex XS-900i hematology analyzer and manual microscopy for blood cell morphology. Paired data was evaluated for agreement and bias using the microhematocrit samples as the reference group and the samples from the microcapillary blood collection tubes as the observation group. The two blood collection methods demonstrated good agreement for measuring red blood cell (RBC) parameters (i.e., RBC, Hb, Hct, MCV, MCH and MCHC), wherein the relative bias was > allowable total error (TEa) in 0.91%, 1.82%, 11.82%, 1.82%, 0.91% and 8.18% of the parameter measures, respectively. According to industry requirements, the proportion of samples meeting the acceptable bias level should be > 80%. Additionally, the estimated biases at each medical decision level were within clinically acceptable levels for RBC, Hb, Hct, and MCV. However, the proportion of WBC and PLT counts with relative bias > TEa was 25.45% and 35.45%, respectively. Furthermore, the relative bias of the WBC count at the medical decision level of 0.5 × 109/L and that of the PLT counts at the medical decision levels of 10 × 109/L and 50 × 109/L were clinically significant. Bland-Altman analysis further showed a mean bias of 0.66 × 109/L (95% LoA, - 0.79 to 2.11) for the WBC count and 39 × 109/L (95% LoA, - 46 to 124) for the PLT count from the blood samples collected in the microcapillary blood collection tubes compared with the counts of those collected in the microhematocrit tubes. Neutrophil, monocyte, lymphocyte, eosinophil, and PLT counts increased significantly in the microcapillary blood collection tubes compared with those in the microhematocrit tubes, along with an elevated number of instrument false alarms (P < 0.05). The two capillary blood collection devices exhibit performance differences. Therefore, clinicians should pay attention to the variation in results caused by different blood collection methods.

Point-of-care testing: state-of-the art and perspectives

Point-of-care testing (POCT) is becoming an increasingly popular way to perform laboratory tests closer to the patient. This option has several recognized advantages, such as accessibility, portability, speed, convenience, ease of use, ever-growing test panels, lower cumulative healthcare costs when used within appropriate clinical pathways, better patient empowerment and engagement, and reduction of certain pre-analytical errors, especially those related to specimen transportation. On the other hand, POCT also poses some limitations and risks, namely the risk of lower accuracy and reliability compared to traditional laboratory tests, quality control and connectivity issues, high dependence on operators (with varying levels of expertise or training), challenges related to patient data management, higher costs per individual test, regulatory and compliance issues such as the need for appropriate validation prior to clinical use (especially for rapid diagnostic tests; RDTs), as well as additional preanalytical sources of error that may remain undetected in this type of testing, which is usually based on whole blood samples (i.e., presence of interfering substances, clotting, hemolysis, etc.). There is no doubt that POCT is a breakthrough innovation in laboratory medicine, but the discussion on its appropriate use requires further debate and initiatives. This collective opinion paper, composed of abstracts of the lectures presented at the two-day expert meeting "Point-Of-Care-Testing: State of the Art and Perspective" (Venice, April 4-5, 2024), aims to provide a thoughtful overview of the state-of-the-art in POCT, its current applications, advantages and potential limitations, as well as some interesting reflections on the future perspectives of this particular field of laboratory medicine.

Venous blood collection systems using evacuated tubes: a systematic review focusing on safety, efficacy and economic implications of integrated vs. combined systems

Venous blood collection systems (VBCSs) are combinations of in-vitro diagnostics and medical devices, usually available as integrated set. However, purchasing and using a combination of devices from different sets is considered by clinical laboratories as an option to achieve specific sampling tasks or reduce costs. This systematic review aimed to retrieve available evidence regarding safety, efficacy, and economic aspects of VBCSs, focusing on differences between integrated and combined systems. The literature review was carried out in PubMed. Cited documents and resources made available by scientific organisations were also screened. Extracted evidence was clustered according to Quality/Efficacy/Performance, Safety, and Costs/Procurement domains and discussed in the current European regulatory framework. Twenty documents published between 2010 and 2021 were included. There was no evidence to suggest equivalence between combined and integrated VBCSs in terms of safety and efficacy. Scientific society's consensus documents and product standards report that combined VBCS can impact operators' and patients' safety. Analytical performances and overall efficacy of combined VBCSs are not guaranteed without whole system validation and verification. EU regulatory framework clearly allocates responsibilities for the validation and verification of an integrated VBCS, but not for combined VBCSs, lacking information about the management of product nonconformities and post-market surveillance. Laboratory validation of combined VBCS demands risk-benefit and cost-benefit analyses, a non-negligible organisational and economic burden, and investment in knowledge acquisition. Implications in terms of laboratory responsibility and legal liability should be part of a comprehensive assessment of safety, efficacy, and cost carried out during device procurement.

Determining the rate and reasons for specimen rejection among specimens referred for HIV viral load determination through referral linkage to Debre Tabor Comprehensive Specialized Hospital, north-central, Ethiopia,2023: Retrospective study

Background

The preanalytical phase encompasses the time between the clinician's test order to the sample being ready for analysis. Of all errors during the laboratory diagnostic process,70 % appeared in the pre-analytical phase. In clinical laboratories, it is crucial to ensure proper specimen collection and handling, which is essential to guarantee quality assessment, monitoring process standardization, improving performance, and ensuring patient safety. Despite this importance, no study has been conducted in the study area to investigate the rate and reasons for human immunodeficiency virus viral load sample rejection.

Objective

To determine the rate of human immunodeficiency virus viral load sample rejection (number of preanalytical errors) documented during the preanalytical phase and articulate possible causes for specimen rejection.

Material and methods

A retrospective study was conducted at Debre Tabor Comprehensive Specialized Hospital from January 1st to January 31, 2023. During the study period, 5950 samples were extracted from the human immunodeficiency virus viral load laboratory sample tracking log books, which were sent to the hospital for viral load testing between August 2021 to November 2022. The collected data were cleaned and entered into EPI data version 4.6 before transferred it to STATA version 14.0 for analysis. Descriptive statistics such as frequencies, percentages, and cross-tabulations were used to summarize the findings.

Results

The study found that improper sample handling was common during the preanalytical phase. According to the current study, 3.6 % of the sample was rejected at pre analytical stage. The most common reasons for specimen rejection were using inappropriate containers (64.0 %) uncentrifuged specimens (20.4 %); hemolyzed specimens (7.0 %); insufficient specimen volume (6.2 %); clotted specimens (1.9 %); and specimen labeling problems (0.5 %).

Conclusion

This study found that the most common preanalytical error was using an inappropriate sample collection container, followed by uncentrifuged samples, Therefore, it is recommended that mentorship programs be developed to educate staff on the preanalytical phase of laboratory testing, specifically on sample collection, storage, and transportation for HIV viral load testing. Additionally, the quality management system of laboratory processes should be strengthened to ensure accuracy and minimize errors.

Subpar reporting of pre-analytical variables in RNA-focused blood plasma studies

Extracellular RNA (cell-free RNA; exRNA) from blood-derived liquid biopsies is an appealing, minimally invasive source of disease biomarkers. As pre-analytical variables strongly influence exRNA measurements, their reporting is essential for meaningful interpretation and replication of results. The aim of this review was to chart to what extent pre-analytical variables are documented, to pinpoint shortcomings and to improve future reporting. In total, 200 blood plasma exRNA studies published in 2018 or 2023 were reviewed for annotation of 22 variables associated with blood collection, plasma preparation, and RNA purification. Our results show that pre-analytical variables are poorly documented, with only three out of 22 variables described in over half of the publications. The percentage of variables reported ranged from 4.6% to 54.6% (mean 24.84%) in 2023 and from 4.6% to 57.1% (mean 28.60%) in 2018. Recommendations and guidelines (i.e., BRISQ, ASCO-CAP, BloodPAC, PPMPT, and CEN standards) have currently not resulted in improved reporting. In conclusion, our results highlight the lack of reporting pre-analytical variables in exRNA studies and advocate for a consistent use of available standards, endorsed by funders and journals.

Solid-Phase Extraction and Enhanced Amplification-Free Detection of Pathogens Integrated by Multifunctional CRISPR-Cas12a

Public healthcare demands effective and pragmatic diagnostic tools to address the escalating challenges in infection management in resource-limited areas. Recent advances in clustered regularly interspaced short palindromic repeat (CRISPR)-based biosensing promise the development of next-generation tools for disease diagnostics, including point-of-care (POC) testing for infectious diseases. The currently prevailing strategy of developing CRISPR/Cas-based diagnostics exploits only the target identification and trans-cleavage activity of a CRISPR-Cas12a/Cas13a system to provide diagnostic results, and they need to be combined with an additional preamplification reaction to enhance sensitivity. In contrast to this dual-function strategy, here, we present a new approach that collaboratively integrates the triple functions of CRISPR-Cas12a: target identification, sequence-specific enrichment, and signal generation. With this approach, we develop a nucleic acid assay termed Solid-Phase Extraction and Enhanced Detection Assay integrated by CRISPR-Cas12a (SPEEDi-CRISPR) that negates the need for preamplification but significantly improves the detection of limit (LOD) from the pM to fM level. Specifically, using Cas12a-coated magnetic beads, this assay combines efficient solid-phase extraction and enrichment of DNA targets enabled by the sequence-specific affinity of CRISPR-Cas12a with fluorogenic detection by activated Cas12a on beads. SPEEDi-CRISPR, for the first time, leverages the possibility of employing CRISPR/Cas12a in nucleic acid extraction and integrates the ability of both enrichment and detection of CRISPR/Cas into a single platform. Our proof-of-concept studies revealed that the SPEEDi-CRISPR assay has great specificity to distinguish HPV-18 from HPV-16, and Parvovirus B19, in addition to being able to detect HPV-18 at a concentration as low as 2.3 fM in 100 min and 4.7 fM in 60 min. Furthermore, we proved that this assay can be coupled with two point-of-care testing strategies: the smartphone-based fluorescence detector and the lateral flow assay. Overall, these results suggested that our assay could pave a new way for developing CRISPR diagnostics.

Preanalytical Errors in Clinical Laboratory Testing at a Glance: Source and Control Measures

The accuracy of diagnostic results in clinical laboratory testing is paramount for informed healthcare decisions and effective patient care. While the focus has traditionally been on the analytical phase, attention has shifted towards optimizing the preanalytical phase due to its significant contribution to total laboratory errors. This review highlights preanalytical errors, their sources, and control measures to improve the quality of laboratory testing. Blood sample quality is a critical concern, with factors such as hemolysis, lipemia, and icterus leading to erroneous results. Sources of preanalytical errors encompass inappropriate test requests, patient preparation lapses, and errors during sample collection, handling, and transportation. Mitigating these errors includes harmonization efforts, education and training programs, automated methods for sample quality assessment, and quality monitoring. Collaboration between laboratory personnel and healthcare professionals is crucial for implementing and sustaining these measures to enhance the accuracy and reliability of diagnostic results, ultimately improving patient care.

Identification of miR-30c-5p microRNA in Serum as a Candidate Biomarker to Diagnose Endometriosis

The diagnosis of endometriosis by laparoscopy is delayed until advanced stages. In recent years, microRNAs have emerged as novel biomarkers for different diseases. These molecules are small non-coding RNA sequences involved in the regulation of gene expression and can be detected in peripheral blood. Our aim was to identify candidate serum microRNAs associated with endometriosis and their role as minimally invasive biomarkers. Serum samples were obtained from 159 women, of whom 77 were diagnosed with endometriosis by laparoscopy and 82 were healthy women. First, a preliminary study identified 29 differentially expressed microRNAs between the two study groups. Next, nine of the differentially expressed microRNAs in the preliminary analysis were evaluated in a new cohort of 67 women with endometriosis and 72 healthy women. Upon validation by quantitative real-time PCR technique, the circulating level of miR-30c-5p was significantly higher in the endometriosis group compared with the healthy women group. The area under the curve value of miR-30c-5p was 0.8437, demonstrating its diagnostic potential even when serum samples registered an acceptable limit of hemolysis. Dysregulation of this microRNA was associated with molecular pathways related to cancer and neuronal processes. We concluded that miR-30c-5p is a potential minimally invasive biomarker of endometriosis, with higher expression in the group of women with endometriosis diagnosed by laparoscopy.

Effect of syringe underfilling on the quality of venous blood gas analysis

OBJECTIVES

There is limited information on the influence of collecting small amounts of blood on the quality of blood gas analysis. Therefore, the purpose of this study was to investigate the effects of different degrees of underfilling of syringes on test results of venous blood gas analysis.

METHODS

Venous blood was collected by venipuncture from 19 healthcare workers in three 1.0 mL syringes for blood gas analysis, by manually aspirating different volumes of blood (i.e., 1.0, 0.5 and 0.25 mL). Routine blood gas analysis was then immediately performed with GEM Premier 5,000. The results of the two underfilled syringes were compared with those of the reference syringe filled with appropriate blood volume.

RESULTS

The values of most assayed parameters did not differ significantly in the two underfilled syringes. Statistically significant variations were found for lactate, hematocrit and total hemoglobin, the values of which gradually increased as the fill volume diminished, as well as for sodium concentration, which decreased in both insufficiently filled blood gas syringes. The bias was clinically meaningful for lactate in syringe filled with 0.25 mL of blood, and for hematocrit, total hemoglobin and sodium in both syringes containing 0.5 and 0.25 mL of blood.

CONCLUSIONS

Collection of smaller volumes of venous blood than the specified filling volume in blood gas syringes may have an effect on the quality of some test results, namely lactate, hematocrit, total hemoglobin and sodium. Specific indications must be given for standardizing the volume of blood to be collected within these syringes.

Artificial intelligence in the pre-analytical phase: State-of-the art and future perspectives

The use of artificial intelligence (AI) has become widespread in many areas of science and medicine, including laboratory medicine. Although it seems obvious that the analytical and post-analytical phases could be the most important fields of application in laboratory medicine, a kaleidoscope of new opportunities has emerged to extend the benefits of AI to many manual labor-intensive activities belonging to the pre-analytical phase, which are inherently characterized by enhanced vulnerability and higher risk of errors. These potential applications involve increasing the appropriateness of test prescription (with computerized physician order entry or demand management tools), improved specimen collection (using active patient recognition, automated specimen labeling, vein recognition and blood collection assistance, along with automated blood drawing), more efficient sample transportation (facilitated by the use of pneumatic transport systems or drones, and monitored with smart blood tubes or data loggers), systematic evaluation of sample quality (by measuring serum indices, fill volume or for detecting sample clotting), as well as error detection and analysis. Therefore, this opinion paper aims to discuss the state-of-the-art and some future possibilities of AI in the preanalytical phase.

Prevalence of pre-diabetes in adults aged 25 - 45 years in a Durban-based clinical setting, South Africa: A retrospective study

AIM

Due to pre-diabetes being underexplored, its prevalence was investigated in study participants aged 25-45 years in a Durban-based tertiary-level clinical setting in South Africa.

METHODS

The study was done using a retrospective study design. Fasting blood samples from consented patients with no previous diagnosis of diabetes and within the specified age range were collected from King Edward Hospital in Durban. The pre-diabetes diagnosis was confirmed in participants with fasting glucose concentrations between 5.6 and 6.9 mmol/L and glycated haemoglobin (HbA1c) levels between 5.7 % and 6.4 % using the American Diabetes Association (ADA) and World Health Organisation (WHO) diagnosis criteria. The study participants' characterisation was stratified according to the diagnosis criterion, age, gender and ethnicity.

RESULTS

An alarming 68 % average pre-diabetes prevalence across ADA and WHO criteria in the Durban, eThekwini district sample population. The highest prevalence was recorded using the IFG criterion (83%) and the lowest when using the HbA1c criterion (54 %). Between the White, Black and Indian ethnic groups, the Indian group were more predisposed to pre-diabetes onset, with a prevalence of 62.7 %.

CONCLUSION

If pre-diabetes management is unattended, an unprecedented increase in metabolic disorders such as Type 2 Diabetes Mellitus (T2DM) and all-cause mortality incidence can be expected. Therefore, the study reveals a window of opportunity to intensify preventative measures and mitigate the incidence of T2DM.

Incomplete filling of spray-dried K2EDTA evacuated blood tubes: impact on measuring routine hematological parameters on Sysmex XN-10

OBJECTIVES

Because there is little published evidence on the effects of incomplete filling of K2EDTA evacuated blood tubes on routine hematological testing, this original study aimed to provide updated information on this preanalytical aspect.

METHODS

The study population consisted of 17 ostensibly healthy volunteers. Blood was drawn by venipuncture with a 10 mL syringe and dispensed in varying amounts (0.2, 0.5, 1.0, 2.0, and 3.0 mL) into 3.0 mL blood tubes containing spray-dried 5.4 mg K2EDTA. All tubes were gently mixed and used to perform routine hematology tests on the Sysmex XN-10. Clinically significant variations were defined when the limits of desirable specifications of bias derived from biologic variation were exceeded.

RESULTS

The desirable bias was exceeded in 33 % filled tubes (1.0 mL) for hematocrit and MCV (increased values) and for MCHC (decreased values), while it was exceeded in 17 % filled tubes (0.5 mL) for hemoglobin, hematocrit and MCV (increased values), and for MCHC (decreased values). Finally, the variation of values was higher than the desirable bias for RBC, hemoglobin, hematocrit and MCV (increase), and for MCHC and MPV (decrease) in 7 % filled tubes (0.2 mL). No clinically significant variations were observed in tubes filled up to 67 % of their nominal volume (i.e., 2.0 mL).

CONCLUSIONS

Consideration should be given to reject spray-dried K2EDTA blood tubes that contain a blood volume <67 % of the nominal fill volume, as biased laboratory data in these samples may interfere with clinical decision making and care management.

Direct costs of blood drawings with pre-analytical errors in tertiary paediatric hospital care

BACKGROUND

Blood drawings is a common hospital procedure involving laboratory and clinical disciplines that is important for the diagnosis and management of illnesses in children. Blood drawings with pre-analytical error (PAE) can lead to increased costs for hospitals and healthcare organisations. The direct cost of blood drawings after a PAE is not fully understood in paediatric hospital care.

AIM

The aim of this study was to estimate the average direct cost of PAE per year and per 10,000 blood drawings in tertiary paediatric care.

METHODS

A cost analysis using a bottom-up approach was conducted on the basis of combined information from the hospital's laboratory register for the period 2013-2014 and clinical in-ward observations at a tertiary children's referral hospital in Sweden, the Astrid Lindgren Children's Hospital. For the analysis, we hypothesised the re-collection of all blood drawings with PAE and included the average costs of the sampling materials, the time of the healthcare personnel, the laboratory analyses, and in-ward premises based on the time spent on the blood sampling procedure.

RESULTS

The annual cost of PAE was estimated to be 74,267 euros per 54,040 blood drawings, which corresponds to 13,756 euros per 10,000 blood drawings or 1.5 euros per draw. The personnel cost represented 60.1% (45,261 euros per year) of the cost due to PAE, followed by costs for hospitalisation (25.2%), laboratory analyses (8.1%), and materials (5.7%).

CONCLUSION

PAEs lead to substantial increases in the costs in tertiary paediatric hospital care. If these PAEs can be avoided, costs related to the re-collection of blood drawings with PAE may be re-allocated to other health-promoting activities for children visiting hospital institutions.

Diagnosis of severe anaemia and positive antibody screening as consequences of pre-analytical error

The pre-analytical phase is the principal source of errors in laboratory medicine and continues to pose a challenge to laboratory professionals. We present the case of a 73-yearold female patient with a very low hemoglobin level (69 g/L) and positive indirect antiglobulin test result that indicates the key role of phlebotomy as an important error-prone process in which mistakes can have serious consequences for the patient's diagnosis and treatment. We conclude that there is still an urgent and continuous need to provide educational activities for healthcare professionals involved in blood collection, improve blood collection guideline adherence, and eliminate the errors which can affect diagnosis and treatment, thus jeopardising patient safety.

Analysis of the Six Sigma Principle in Pre-analytical Quality for Hematological Specimens

Introduction Blood tests are essential for detecting and treating hospitalized individuals with diseases. Laboratory blood tests provide doctors with critical information required to treat their patient's illnesses. The most common sources of error in clinical laboratories are pre-analytical errors. Although quality control measures can remediate analytical errors, there is a requirement for stringent quality checks in the pre-analytical sector as these activities are performed outside of the laboratory. Pre-analytical errors when combined with the sigma value can reflect a better picture as the sigma value represents the laboratory's performance.  Aim In this study, six sigma and the Pareto principle were utilized to assess pre-analytical quality indicators for evaluating the performance of a clinical hematology laboratory.  Methodology  This is a retrospective observational study conducted from 2015 to 2023 (for a period of eight years). Information about the frequency of pre-analytical errors was retrieved from the hematology section of the central diagnostic research laboratory information system and the data was entered into an MS Excel sheet and data was evaluated utilizing SPSS version 23 (IBM Corp., Armonk, NY). Results In the current research, total of 15 pre-analytical errors were noted. Out of the total 15 pre-analytical errors studied, 55.4% of pre-analytical errors were noted among which 80% errors were due to lack of mention of sample type or received time and 20% of errors were attributed to no mention of diagnosis in requisition forms. The next most common errors noted were insufficient samples (8.26%) followed by absence of physician's signature (7%), incomplete request form (5.4%), age (4.2%), unique hospital identification (UHID) number (3.7%), clotted samples and transportation of the samples (3.6%), date and incorrect vials (2.6%). Gender (0.95%), hemolysed (0.85%), and lipemic samples (0.45%). Hemolysed and lipemic samples had a sigma value of 4.4 and 4.6, respectively, whereas gender and age had a sigma value of 4.3 and 3.8, inadequate sample for testing and an incorrect anticoagulant to blood ratio had a sigma value of 3.6, indicating that sample collection has to be improved as the inverse relationship is noted between sigma value and laboratory performance. Conclusion Pareto chart and sigma value can help recognize most common pre-analytical errors, which consequently will help to prevent further recurrence of pre-analytical errors. Adequate training with regard to best practices in phlebotomy for interns, clinicians and technicians must be provided to decrease quantitative errors, which will further enhance total quality management in the laboratory.

Solid-Phase Extraction and Enhanced Amplification-Free Detection of Pathogens Integrated by Dual-Functional CRISPR-Cas12a

Public healthcare demands effective and pragmatic diagnostic tools to address the escalating challenges in infection management in resource-limited areas. Recent advance in CRISPR-based biosensing promises the development of next-generation tools for disease diagnostics, including point-of-care (POC) testing for infectious diseases. Currently prevailing strategy of developing CRISPR assays exploits only the non-specific trans-cleavage function of a CRISPR-Cas12a/Cas13a system for detection and combines it with an additional pre-amplification reaction to enhance the sensitivity. In contrast to this single-function strategy, here we present a new approach that collaboratively integrates the dual functions of CRISPR-Cas12a: sequence-specific binding and trans-cleavage activity. With this approach, we developed a POC nucleic acid assay termed Solid-Phase Extraction and Enhanced Detection assay Integrated by CRISPR-Cas12a (SPEEDi-CRISPR) that negates the need for preamplification but significantly improves the detection of limit (LOD) from the pM to fM level. Specifically, using Cas12a-coated magnetic beads, this assay combines efficient solid-phase extraction and enrichment of DNA targets enabled by the sequence-specific affinity of CRISPR-Cas12a with the fluorogenic detection by the activated Cas12a on beads. Our proof-of-concept study demonstrated that the SPEEDi-CRISPR assay affords an improved detection sensitivity for human papillomavirus (HPV)-18 with a LOD of 2.3 fM and excellent specificity to discriminate HPV-18 from HPV-16, Parvovirus B19, and scramble HPV-18. Furthermore, this robust assay was readily coupled with a portable smartphone-based fluorescence detector and a lateral flow assay for quantitative detection and visualized readout, respectively. Overall, these results should suggest that our dual-function strategy could pave a new way for developing the next-generation CRISPR diagnostics and that the SPEEDi-CRISPR assay provides a potentially useful tool for point-of-care testing.

Microsampling tools for collecting, processing, and storing blood at the point-of-care

In the wake of the COVID-19 global pandemic, self-administered microsampling tools have reemerged as an effective means to maintain routine healthcare assessments without inundating hospitals or clinics. Finger-stick collection of blood is easily performed at home, in the workplace, or at the point-of-care, obviating the need for a trained phlebotomist. While the initial collection of blood is facile, the diagnostic or clinical utility of the sample is dependent on how the sample is processed and stored prior to transport to an analytical laboratory. The past decade has seen incredible innovation for the development of new materials and technologies to collect low-volume samples of blood with excellent precision that operate independently of the hematocrit effect. The final application of that blood (i.e., the test to be performed) ultimately dictates the collection and storage approach as certain materials or chemical reagents can render a sample diagnostically useless. Consequently, there is not a single microsampling tool that is capable of addressing every clinical need at this time. In this review, we highlight technologies designed for patient-centric microsampling blood at the point-of-care and discuss their utility for quantitative sampling as a function of collection material and technique. In addition to surveying methods for collecting and storing whole blood, we emphasize the need for direct separation of the cellular and liquid components of blood to produce cell-free plasma to expand clinical utility. Integrating advanced functionality while maintaining simple user operation presents a viable means of revolutionizing self-administered microsampling, establishing new avenues for innovation in materials science, and expanding access to healthcare.

Preanalytical Errors in Clinical Biochemistry Laboratory and Relationship With Hospital Departments and Staff: A Record-Based Study

OBJECTIVE

Despite many efforts to improve the overall quality of clinical laboratory service, errors that compromise patient safety and increase healthcare costs continue to occur even infrequently. We aimed to determine the causes of preanalytical errors and related factors by evaluating the laboratory records of a tertiary hospital.

METHODS

In this retrospective study, 7,762,981 requests that were registered in the biochemistry laboratory records of Ondokuz Mayıs University Health Practice and Research Center during 2019 were examined. All rejected samples were analyzed according to the department where they were collected and the reasons for rejection.

RESULTS

Of the total sample rejections, 99,561 (74.8%) were preanalytical and 33,474 (25.2%) belonged to the analytical phase. The preanalytical rejection rate was 1.28%, with the highest rejection rate in the inpatients (2.26%) and the lowest in the outpatients (0.02%). Insufficient sample (43.7%), clotted sample (35.1%), and inappropriate sample (11.1%) were the first 3 rows of rejection reasons. It was determined that sample rejection rates were low during routine working hours and high during nonworking hours.

CONCLUSIONS

Preanalytical errors were most common in inpatient wards and were most likely due to incorrect phlebotomy techniques. Education of health personnel on good laboratory practices, systematic monitoring of errors, and the development of quality indicators will play an important role in reducing the vulnerability of the preanalytical phase.

Fibrin clot interference in a human chorionic gonadotrophin assay causing a false Down syndrome screening result

Serum samples are generally used for the measurement of human chorionic gonadotrophin (hCG) to calculate second-trimester maternal screening results. Lower hCG concentrations correlate with a lower calculated risk of Down syndrome (DS). Hence, erroneously low hCG results due to fibrin clot may lead to misinterpretation. We present a 23-year-old woman with a pregnancy of 17+3 weeks. Blood was taken into the Becton-Dickinson (BD) vacutainer SST-II Advance tube (Ref: 367955). The hCG test was performed on Immulite 2000 XPi analyser (Siemens Healthcare Diagnostics Inc, Tarrytown, USA) with original reagents. The results of the same sample were found as 2566 U/L, 18,153 U/L, and 7748 U/L. Three consecutive results after removal of the small fibrin clot and recentrifugation were 18,878, 20,255, and 22,339 U/L. The risk of DS and MoM for the concentration of 2556 U/L hCG was < 1/10,000 and 0.14, respectively. For a hCG concentration of 20,255 U/L, these values were 1/5632 and 1.13, respectively. Laboratory professionals and technicians should be aware that erroneously low hCG results can be measured with the Immulite 2000 XPi due to interference from small fibrin clots. Falsely underestimated hCG values reduce the MoM values and thus the calculated risk of DS.

Undefilled blood tube containing EDTA: Is it an inappropriate sample for HbA1c assay?

Introduction

Blood samples having inappropriate volume are a substantial part of preanalytical errors. Inadequate sample volume for glycated haemoglobin (HbA1c) test may be a common problem of patients with diabetes mellitus having vascular changes. In this study, we compared HbA1c concentrations of underfilled and appropriately filled blood collection tubes.

Materials and methods

To compare HbA1c concentrations, blood samples were collected into 2 mL tubes containing K3-EDTA from 109 subjects. Two blood samples (underfilled and appropriately filled) were drawn from a patient by the same personnel and materials. HbA1c measurements were assayed on a Cobas 6000 analyser module c 501 (Roche Diagnostics, Mannheim, Germany). The HbA1c% results were compared by t-test and Wilcoxon's signed-rank statistical methods (SPSS Inc., Chicago, USA). Bias analysis was performed using Microsoft Excel 4.0.

Results

Underfilled samples were classified three groups (group 1, N = 44; group 2, N = 36; and group 3, N = 29) according to the filling ratio of the samples; 0.5 mL and below (< 25%), 0.5-1.0 mL (25-50%), and 1.0-2.0 mL (> 50%), respectively. When we compared underfilled tubes with pairing filled tubes, there was a statistically significant difference only with tubes filled less than 25% (P = 0.030). Furthermore, we have done bias analysis between paired tubes according to the diagnostic cut-off value of 6.5%. The bias was more prominent in up to 50% underfilled blood tubes (1.1%), when HbA1c concentrations were below the diagnostic cut-off of 6.5%.

Conclusions

We suggest that the blood tubes with EDTA for HbA1c measurement should be filled with at least 50% to avoid clinical variations.

An overview of the most important preanalytical factors influencing the clinical performance of SARS-CoV-2 antigen rapid diagnostic tests (Ag-RDTs)

Due to the many technical limitations of molecular biology, the possibility to sustain enormous volumes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic testing relies strongly on the use of antigen rapid diagnostic tests (Ag-RDTs). Besides a limited analytical sensitivity, the manually intensive test procedures needed for performing these tests, very often performed by unskilled personnel or by the patients themselves, may contribute to considerably impair their diagnostic accuracy. We provide here an updated overview on the leading preanalytical drawbacks that may impair SARS-CoV-2 Ag-RDT accuracy, and which encompass lower diagnostic sensitivity in certain age groups, in asymptomatic subjects and those with a longer time from symptoms onset, in vaccine recipients, in individuals not appropriately trained to their usage, in those recently using oral or nasal virucidal agents, in oropharyngeal swabs and saliva, as well as in circumstances when instructions provided by the manufacturers are unclear, incomplete or scarcely readable and intelligible. Acknowledging these important preanalytical limitations will lead the way to a better, more clinically efficient and even safer use of this important technology, which represents an extremely valuable resource for management of the ongoing pandemic.

Magnitude of extra-analytical errors and associated factors in medical laboratories in thirteen Public Hospitals in Addis Ababa, Ethiopia

Background

Currently, more than two-thirds of medical decisions are made based on laboratory test results. However, due to the compromised pre-analytical and post-analytical phases (or extra-analytical phase), the reporting of incorrect or inappropriate test results was still prevalent. Studies focusing on the prevalence of and factors associated with laboratory error remain very limited in Ethiopia.

Objective

This study aimed to assess the magnitude of extra-analytical errors and associated factors in medical laboratory services in 13 public hospitals in Addis Ababa, Ethiopia, from January to April 2020.

Materials and Methods

A hospital-based cross-sectional study was conducted in the medical laboratories of public hospitals in Addis Ababa from January to April 2020 to assess extra-analytical errors and associated factors. Data were collected from 2401 laboratory request forms ordered within the study period and 169 laboratory professionals working in public hospitals. The collected data were entered and analyzed using SPSS version 23 software. Data were analyzed using simple descriptive statistics, percentages, and frequencies and summarized using tables and text. Bivariate logistic regression analysis was conducted, and variables (with a p value below 0.25) were included in the multivariate logistic regression model. A p value <0.05 was considered a cutoff point in the final model.

Results

In this study, of the errors detected, 60.3% occurred in the pre-analytical phase and 39.7% in the post-analytical phase. Extra-analytical errors in laboratory services were significantly associated with lack of written procedures for laboratory activities (adjusted odds ratio = 2.79, 95% confidence interval = 1.34-5.86), 1-2 years of work experience (adjusted odds ratio = 5.5, 95% confidence interval = 2.54-9.31), work experience (3-5 years) (adjusted odds ratio = 2.67, 95% confidence interval = 0.94-4.56), and education (diploma) (adjusted odds ratio = 6.30, 95% confidence interval = 2.17-12.26).

Conclusion

This study discovered errors in the pre-analytical (60.3%) and post-analytical (39.7%) phases, and none of the requisition papers had complete data. This frequency may be affected by workload, a lack of written procedures, the number of years of work experience, and the level of education of the staff.

D-dimer Testing in Pulmonary Embolism with a Focus on Potential Pitfalls: A Narrative Review

D-dimer is a multifaceted biomarker of concomitant activation of coagulation and fibrinolysis, which is routinely used for ruling out pulmonary embolism (PE) and/or deep vein thrombosis (DVT) combined with a clinical pretest probability assessment. The intended use of the tests depends largely on the assay used, and local guidance should be applied. D-dimer testing may suffer from diagnostic errors occurring throughout the pre-analytical, analytical, and post-analytical phases of the testing process. This review aims to provide an overview of D-dimer testing and its value in diagnosing PE and discusses the variables that may impact the quality of its laboratory assessment.

A case of discrepant laboratory results in samples obtained from a central venous catheter and peripheral veins: when solving a pre-analytical mystery could improve patient care

It is now generally accepted that laboratory errors or inaccurate results are mainly due to deficiencies in the pre-analytical phase. In this report, we describe the case of a 64-year-old male affected by a relapsing follicular lymphoma, who has been treated with chemotherapy through a central venous catheter (CVC). Four different samples were collected alternatively through peripheral venipuncture and CVC sampling. Unexpectedly, the samples collected from the two different sources showed contrasting results, with the presence of unusual macrophage-like cells in the samples obtained from CVC. It was later found that the CVC was displaced into the pleural space. This case report shows how the sampling process can sometimes influence test results and how it can help clinicians identify clinical conditions that have not yet manifested.

The effect of hemolysis on quality control metrics for noninvasive prenatal testing

Background

Noninvasive prenatal testing (NIPT) is the testing of blood samples from pregnant women to screen for fetal risk of chromosomal disorders. Even though in vitro hemolysis of blood specimens is common in clinical laboratories, its influence on NIPT has not been well investigated.

Methods

Peripheral blood samples were collected from 205 pregnant women and categorized according to the concentration of free hemoglobin in the plasma. After performing NIPT using massively parallel sequencing, the quality control metrics were analyzed and compared with samples that did not undergo hemolysis or samples redrawn from the same women.

Results

The specimens were divided into four groups based on the concentration of free hemoglobin: Group I (0–1 g/L, n = 53), Group II (1–2 g/L, n = 97), Group III (2–4 g/L, n = 30), and Group IV (> 4 g/L, n = 25). There was no significant difference in the quality control metrics of clinical samples with slight or moderate hemolysis (Group II and III). However, samples with severe hemolysis (Group IV) showed a significantly increased rate of duplicated reads (duplication rate) and fetal fraction, as well as decreased library concentration compared with samples without hemolysis. Moreover, the increase in fetal fraction caused by hemolysis was confirmed by redrawing blood samples in Group IV.

Conclusion

For NIPT using massively parallel sequencing, samples with slight or moderate hemolysis (≤ 4 g/L) are acceptable. However, careful consideration should be taken regarding the use of severely hemolyzed samples (> 4 g/L), since they might increase the risk of test failure.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01280-2.

Introduction of BD Vacutainer® Barricor™ tubes in clinical biobanking and application of amino acid and cytokine quality indicators to Barricor plasma

OBJECTIVES

The use of BD Vacutainer® Barricor™ tubes (BAR) can reduce turnaround time (TAT) and improve separation of plasma from cellular components using a specific mechanical separator. Concentrations of amino acids (AAs) and cytokines, known to be labile during pre-analytical time delays, were compared in heparin (BAR, BD Heparin standard tube [PST]), EDTA and serum gel tubes (SER) to validate previously identified quality indicators (QIs) in BAR.

METHODS

Samples of healthy individuals (n=10) were collected in heparin, EDTA and SER tubes and exposed to varying pre- and post-centrifugation delays at room temperature (RT). Cytokines (interleukin [IL]-8, IL-16 and sCD40L) were analyzed by enzyme-linked immunosorbent assay (ELISA) and AAs were characterized by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS).

RESULTS

All QIs, AAs/AA ratio and cytokines increased during prolonged blood storage in heparin plasma (PST, BAR) and SER tubes. Comparison of 53 h/1 h pre-centrifugation delay resulted in an increase in taurine (Tau) and glutamic acid (Glu) concentrations by more than three times, soluble CD40L increased by 13.6, 9.2 and 4.3 fold in PST, BAR-CTRL and BAR-FAST, and IL-8 increased even more by 112.8 (PST), 266.1 (BAR-CTRL), 268.1 (BAR-FAST) and 70.0 (SER) fold, respectively. Overall, compared to prolonged blood storage, effects of post-centrifugation delays were less pronounced in all tested materials.

CONCLUSIONS

BAR tubes are compatible with the use of several established QIs and can therefore be used in clinical biobanking to reduce pre-analytical TAT without compromising QIs and thus pre-analytical sample quality analysis.

Nurses' experiences of blood sample collection from children: a qualitative study from Swedish paediatric hospital care

Background

Nurses play an active role in supporting the children with the blood sampling experience. Unfortunately, the blood sampling collection procedure is often affected by pre-analytical errors, leading to consequences such as delayed diagnosis as well as repeated sampling. Moreover, children state that needle procedures are the worst experience of their hospital stay. The nurses’ experiences of errors occurring during blood sample collection is unknown. Therefore, the aim of this study therefore was to describe paediatric nurses’ experiences of blood sampling collections from children.

Method

We used a qualitative study design with a (reflexive) thematic analysis (TA) method described by Braun and Clarke. Three focus group interviews were conducted, with 19 nurses collected by purposeful sampling from Sweden working at two different paediatric hospitals, focusing on their experiences of the blood sample collection procedure.

Results

From the three focus group interviews we analysed patterns and meanings of the following main theme Paediatric blood sampling is a challenge for the nurses and the four subthemes Nurses’ feelings of frustration with unsuccessful samplings, Nurses believe in team work, Venous blood sampling was experienced as the best option, and Nurses’ thoughts and needs regarding skills development in paediatric blood sampling.

Conclusion

The narrative results of this study illustrate that nurses working in paediatric hospital care face a big challenge in blood sampling collection from children. The nurses felt frustrated due to unsuccessful blood samplings and frequently could not understand why pre-analytical errors occurred. Nevertheless, they felt strengthened by colleagues in their team and shared feelings of responsibility to help each other with this complex procedure. The implications of this study are that paediatric hospital care needs to focus on improving guidelines for and increasing competence in blood sampling children and helping nurses to understand why samplings may be unsuccessful and how this can be avoided.

Accuracy of the Data of Biochemical Parameters in Blood Collected Above the Infusion Insertion Site

The authors aimed to investigate the possibility of collecting blood samples from above patient intravenous infusion sites by temporarily stopping the infusions while collecting the blood. A hypotonic infusion solution was administered to 5 male patients through the cephalic veins in the forearms of their left upper limbs. The biochemical data of blood collected from the median cubital veins of both patients' arms were compared. The results showed that infusions could change some biochemical test parameters, such as potassium and glucose, to higher levels, even if the infusion was interrupted temporarily during the blood collection from above the insertion site. Blood counts remained unchanged under the same conditions. If the evaluation is performed solely to assess blood counts, using a blood collection site above the insertion site by temporarily interrupting the infusion is feasible.

COMPARISON OF THREE ANALYZERS FOR ASSESSING COMPLETE BLOOD COUNTS IN NONHUMAN PRIMATES

Diagnostic hematology can prove challenging to the exotic animal practitioner presented with a nonhuman primate patient. Few point-of-care automated cell counters are calibrated for primate samples. Twenty-one samples from 17 nonhuman primates presented to an exotic animal practice were analyzed. Samples were run on both canine and feline settings on each of two veterinary point-of-care analyzers: one that assays by impedance technology, and one that assays by laser flow cytometry. Samples were also sent to a reference laboratory to be assayed on an analyzer that performs simultaneous impedance and laser measurements of blood cells and has been calibrated for use in nonhuman primates. Fourteen analytes were assessed for each sample on each machine. Manual hematocrits and total white blood cell counts were also performed on 16 of the samples. Statistical analysis indicated some variance between individual parameters, but overall correlation was acceptable.

Fusion-positive non-small cell lung carcinoma: Biological principles, clinical practice, and diagnostic implications

Based on superior efficacy and tolerability, targeted therapy is currently preferred over chemotherapy and/or immunotherapy for actionable gene fusions that occur in late-stage non-small cell lung carcinoma (NSCLC). Consequently, current clinical practice guidelines mandate testing for ALK, ROS1, NTRK, and RET gene fusions in all patients with newly diagnosed advanced non-squamous NSCLC (NS-NSCLC). Gene fusions can be detected using different approaches, but today RNA next-generation sequencing (NGS) or combined DNA/RNA NGS is the method of choice. The discovery of other gene fusions (involving, eg, NRG1, NUT, FGFR1, FGFR2, MET, BRAF, EGFR, SMARC fusions) and their partners has increased progressively in recent years, leading to the development of new and promising therapies and mandating the development and implementation of comprehensive detection methods. The purpose of this review is to focus on recent data concerning the main gene fusions identified in NSCLC, followed by the discussion of major challenges in this domain.

A New List for Choosing Wisely Canada From the "Hidden Profession" of Medical Laboratory Science

OBJECTIVES

Choosing Wisely Canada (CWC) publishes practices that may contribute to medical overuse and patient harm. Many practices concern laboratory testing, but the recommendations are often written for the test-ordering professionals. Our objective was to develop a list for CWC reflecting the scope of practice of nonpathologist medical laboratory professionals (MLPs).

METHODS

We used a national survey, a convention session, and a panel of MLPs from across Canada to generate content for the CWC list. We used a modified Delphi process to identify the most important items and scoping reviews to gather evidence supporting each item.

RESULTS

We identified 95 potential CWC list items. After 2 Delphi rounds, there was little movement in the top items. Scoping reviews revealed varying degrees of evidentiary support, which influenced the composition of the final list of 7 CWC items submitted. Three of the final recommendations address ways MLPs preserve the status quo with respect to overutilization of laboratory tests by other health care professionals. The remaining recommendations prompt MLPs to exert clinical judgment in specific scenarios, particularly where they can impact blood collection volumes.

CONCLUSIONS

This work brings a more nuanced and comprehensive understanding of the relationships among MLPs, patient safety, and resource waste.

Pre-Analytical Modification of Serum miRNAs: Diagnostic Reliability of Serum miRNAs in Hemolytic Diseases

Circulating microRNAs (miRNAs) are useful biomarkers of hemolysis. Since blood cells are the main origins of circulating miRNAs, we evaluated blood cell-related pre-analytical modification of the miRNA signatures during blood drawing and serum processing. The levels of miRNA before and after ex vivo blood drawing were analyzed with the reverse transcriptase-based polymerase chain reaction method. Furthermore, the changes of miRNA signatures caused by different time-lag between blood drawing and serum preparation by 24 h were evaluated. Finally, we compared the miRNA levels between leftover samples and samples of hemolytic diseases. Blood drawing procedure induced increments of red blood cell (RBC)-related miRNAs (miR-451a, miR-486) about 2-fold. One hour standing of blood samples before serum separation induced almost the same increases in RBC-related miRNAs. To test the clinical usefulness of miR-451a as a biomarker of hemolytic diseases, we analyzed miRNAs of samples from 10 normal subjects, 30 leftover samples in the clinical laboratory, and 20 samples from patients with hemolytic diseases. Serum miR-451a significantly increased in patients with hemolytic anemia more than the levels of pre-analytical modification. In conclusion, the pre-analytical modification of serum miRNAs did not disturb the usefulness of RBC-derived miRNAs as biomarkers of hemolytic diseases.

Levels of haemolysis have no effect on femoral vein post-mortem tryptase levels

Haemolysis is reported to be an artefact that may alter post-mortem tryptase levels. However, previous studies did not sample peripheral blood using newly standardised methods. Recent studies have shown that some previously recognised peri- and post-mortem confounders can be muted by careful sample collection with first clamping and then sampling the femoral vein. This prospective study investigated the relationship between the degree of haemolysis of the blood samples and femoral vein post-mortem tryptase levels when sampled using this recommended method. Seventy consecutive post-mortem tryptase levels in non-anaphylactic deaths were compared to the degree of haemolysis of these samples, and results showed no significant correlation between them. The mean post-mortem tryptase level was 9.5 μg/L. This study demonstrated that the effects of haemolysis on femoral vein post-mortem tryptase was negligible when the blood was sampled using the recommended sampling method. Future studies on post-mortem tryptase as well as other typically used blood markers in forensics are recommended to adopt this method of blood sampling in routine practice.

The Known Unknowns: An Overview of the State of Blood-Based Protein Biomarkers of Mild Traumatic Brain Injury

Blood-based protein biomarkers have revolutionized several fields of medicine by enabling molecular level diagnosis, as well as monitoring disease progression and treatment efficacy. Traumatic brain injury (TBI) so far has benefitted only moderately from using protein biomarkers to improve injury outcome. Because of its complexity and dynamic nature, TBI, especially its most prevalent mild form (mild TBI; mTBI), presents unique challenges toward protein biomarker discovery and validation given that blood is frequently obtained and processed outside of the clinical laboratory (e.g., athletic fields, battlefield) under variable conditions. As it stands, the field of mTBI blood biomarkers faces a number of outstanding questions. Do elevated blood levels of currently used biomarkers-ubiquitin carboxy-terminal hydrolase L1, glial fibrillary acidic protein, neurofilament light chain, and tau/p-tau-truly mirror the extent of parenchymal damage? Do these different proteins represent distinct injury mechanisms? Is the blood-brain barrier a "brick wall"? What is the relationship between intra- versus extracranial values? Does prolonged elevation of blood levels reflect de novo release or extended protein half-lives? Does biological sex affect the pathobiological responses after mTBI and thus blood levels of protein biomarkers? At the practical level, it is unknown how pre-analytical variables-sample collection, preparation, handling, and stability-affect the quality and reliability of biomarker data. The ever-increasing sensitivity of assay systems and lack of quality control of samples, combined with the almost complete reliance on antibody-based assay platforms, represent important unsolved issues given that false-negative results can lead to false clinical decision making and adverse outcomes. This article serves as a commentary on the state of mTBI biomarkers and the landscape of significant challenges. We highlight and discusses several biological and methodological "known unknowns" and close with some practical recommendations.

Pre-analytical considerations in biomarker research: focus on cardiovascular disease

Clinical biomarker research is growing at a fast pace, particularly in the cardiovascular field, due to the demanding requirement to provide personalized precision medicine. The lack of a distinct molecular signature for each cardiovascular derangement results in a one-size-fits-all diagnostic and therapeutic approach, which may partially explain suboptimal outcomes in heterogeneous cardiovascular diseases (e.g., heart failure with preserved ejection fraction). A multidimensional approach using different biomarkers is quickly evolving, but it is necessary to consider pre-analytical variables, those to which a biological sample is subject before being analyzed, namely sample collection, handling, processing, and storage. Pre-analytical errors can induce systematic bias and imprecision, which may compromise research results, and are easy to avoid with an adequate study design. Academic clinicians and investigators must be aware of the basic considerations for biospecimen management and essential pre-analytical recommendations as lynchpin for biological material to provide efficient and valid data.

Interferograms plotted with reference change value (RCV) may facilitate the management of hemolyzed samples

Background

The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for Preanalytical Phase (WG-PRE) have recommended an algorithm based on the reference change value (RCV) to evaluate hemolysis. We utilized this algorithm to analyze hemolysis-sensitive parameters.

Methods

Two tubes of blood were collected from each of the 10 participants, one of which was subjected to mechanical trauma while the other was centrifuged directly. Subsequently, the samples were diluted with the participant's hemolyzed sample to obtain the desired hemoglobin concentrations (0, 1, 2, 4, 6, 8, and 10 g/L). ALT, AST, K, LDH, T. Bil tests were performed using Beckman Coulter AU680 analyzer. The analytical and clinical cut-offs were based on the biological variation for the allowable imprecision and RCV. The algorithms could report the values directly below the analytical cut-off or those between the analytical and clinical cut-offs with comments. If the change was above the clinical cut-off, the test was rejected. The linear regression was used for interferograms, and the hemoglobin concentrations corresponding to cut-offs were calculated via the interferograms.

Results

The RCV was calculated as 29.6% for ALT. Therefore, ALT should be rejected in samples containing >5.9 g/L hemoglobin. The RCVs for AST, K, LDH, and T. Bil were calculated as 27.9%, 12.1%, 19.2%, and 61.2%, while the samples' hemoglobin concentrations for test rejection were 0.8, 1.6, 0.5, and 2.2 g/L, respectively.

Conclusions

Algorithms prepared with RCV could provide evidence-based results and objectively manage hemolyzed samples.

The impact of blood sampling technique, including the use of peripheral intravenous cannula, on haemolysis rates: A cohort study

AIMS

To explore the relationship between blood sampling techniques and haemolysis.

BACKGROUND

Haemolysis rates of blood samples have been thought to be influenced by the method of collection. There is a lack of research evidence available to clearly show the comparative risk of haemolysis across different blood sampling methods, including venepuncture and use of peripheral intravenous cannulas.

DESIGN

A prospective cohort study. Reporting followed the STROBE checklist.

METHODS

A trained observer was used to record blood sampling techniques over a 10-week period between April and June 2019. These records were then linked to pathology haemolysis results. Multivariable logistic regression was used to model patient and blood draw characteristics affecting haemolysis.

RESULTS

Most of the blood samples were not haemolysed (n = 324, 87.1%). Multivariable analysis showed haemolysis was associated with increased tourniquet duration and if the level of tube was less than half full. Univariable analysis showed haemolysis was associated with increased age of the patient, the difficulty of cannulation/ venepuncture and increased number of attempts. No difference was found in the haemolysis rate related to the qualification of the blood collector.

CONCLUSION

There was no significant difference in haemolysis rates associated with sampling blood from a PIVC compared with venepuncture. Research should be undertaken to determine whether education on the factors influencing haemolysis is useful in decreasing haemolysis rates.

RELEVANCE TO CLINICAL PRACTICE

There was no association with increased haemolysis rates when drawing blood via venepuncture compared with a peripheral intravenous cannula. Haemolysis of blood samples was associated with increased tourniquet duration, if level of the tube was less than half-filled, increased age of the patient and difficulty of blood draw. Awareness of the risk of haemolysis associated with specific blood sampling methods may assist clinicians to improve care.

Preanalytical Sample Handling Conditions and Their Effects on the Human Serum Metabolome in Epidemiologic Studies

Many epidemiologic studies use metabolomics for discovery-based research. The degree to which sample handling may influence findings, however, is poorly understood. In 2016, serum samples from 13 volunteers from the US Department of Agriculture's Beltsville Human Nutrition Research Center were subjected to different clotting (30 minutes/120 minutes) and refrigeration (0 minutes/24 hours) conditions, as well as different numbers (0/1/4) and temperatures (ice/refrigerator/room temperature) of thaws. The median absolute percent difference (APD) between metabolite levels and correlations between levels across conditions were estimated for 628 metabolites. The potential for handling artifacts to induce false-positive associations was estimated using variable hypothetical scenarios in which 1%-100% of case samples had different handling than control samples. All handling conditions influenced metabolite levels. Across metabolites, the median APD when extending clotting time was 9.08%. When increasing the number of thaws from 0 to 4, the median APD was 10.05% for ice and 5.54% for room temperature. Metabolite levels were correlated highly across conditions (all r's ≥ 0.84), indicating that relative ranks were preserved. However, if handling varied even modestly by case status, our hypotheticals showed that results can be biased and can result in false-positive findings. Sample handling affects levels of metabolites, and special care should be taken to minimize effects. Shorter room-temperature thaws should be preferred over longer ice thaws, and handling should be meticulously matched by case status.

Quality improvement project: Reducing non-conformities of the samples for haemostasis testing in a secondary healthcare centre through the nurses' education in phlebotomy

Introduction

Poor compliance to the current guidelines and lack of knowledge among nurses about proper blood sampling is set as the study hypothesis. Here is presented a quality improvement project with following aims: a) to identify the most prevalent non-conformity of the samples for haemostasis testing, b) to identify the cause of sample non-conformity, c) to perform corrective action(s) and d) to assess the effectiveness of the corrective action(s).

Materials and methods

The rate of non-conformity of samples collected for haemostasis tests was established for hospital wards with inpatients. Phlebotomy practice was audited throughout anonymous questionnaire among hospital’s nurses who perform phlebotomy. Education about blood sampling was performed as a 1-hour lecture in different small groups each working day within one month. Education effectiveness was assessed through the evaluation of sample quality and is considered effective if more than half of the hospital wards significantly reduced their sample non-conformities rate.

Results

Clotted sample constituted 84% of sample non-conformities. The questionnaire revealed nurses’ poor knowledge in phlebotomy. There was no difference in nurses’ knowledge regarding the level of education or work experience. Reduction in sample non-conformities was observed in 7 out of 9 wards 4 months after education; this improvement was statistically significant for 5 wards.

Conclusion

Clotted sample as the most prevalent non-conformity of the samples for haemostasis testing is caused by the lack of knowledge of the nurses in several parts of the phlebotomy process. Specific education of the motivated personnel in small groups was successful and long-term effective.

VIDA-Nursing v1.0: immersive virtual reality in vacuum blood collection among adults

OBJECTIVE

to develop and validate the first immersive virtual reality simulation addressing vacuum blood collection in adult patients - VIDA-Nursing v1.0.

METHOD

methodological study to validate 14 steps of the vacuum blood collection procedure in adults, designed to develop the immersive virtual reality simulator VIDA-Nursing v1.0. It was assessed by 15 health workers and 15 nursing undergraduate students in terms of visual, interactive, movement simulation reality, teaching and user-friendly aspects.

RESULTS

the workers considered 79.6% of the items to be valid, while the students considered 66.7% of the items valid; most of the demands can be implemented in the system by improving future versions.

CONCLUSION

the simulator was considered a promising and innovative tool to teach vacuum blood collection in adults as it can be combined with other resources currently used to introduce this topic and technique in the education of undergraduate nursing students.

Pre-analytical issues in liquid biopsy – where do we stand?

It is well documented that in the chain from sample to the result in a clinical laboratory, the pre-analytical phase is the weakest and most vulnerable link. This also holds for the use and analysis of extracellular nucleic acids. In this short review, we will summarize and critically evaluate the most important steps of the pre-analytical phase, i.e. the choice of the best control population for the patients to be analyzed, the actual blood draw, the choice of tubes for blood drawing, the impact of delayed processing of blood samples, the best method for getting rid of cells and debris, the choice of matrix, i.e. plasma vs. serum vs. other body fluids, and the impact of long-term storage of cell-free liquids on the outcome. Even if the analysis of cell-free nucleic acids has already become a routine application in the area of non-invasive prenatal screening (NIPS) and in the care of cancer patients (search for resistance mutations in the EGFR gene), there are still many unresolved issues of the pre-analytical phase which need to be urgently tackled.

Routine coagulation testing in Vacutainer® Citrate Plus tubes filled at minimum or optimal volume

Background Filling of citrate tubes with appropriate amount of blood is essential for obtaining reliable results of coagulation testing. This study aimed to verify whether results of routine coagulation tests are comparable when the new Becton Dickinson Vacutainer® Citrate Plus tubes are filled at minimum or optimal volume. Methods The study population consisted of 133 patients (40 on oral anticoagulant therapy), who had blood collected for routine coagulation testing. Two sequential Vacutainer® Citrate Plus tubes of the same type and lot were drawn. The first tube was collected after a butterfly needle was inserted into the vein, so that the air in the tubing was aspirated into the tube before blood (minimum fill volume), whilst the second was drawn at optimal fill volume. Experiments were repeated using 2.7-mL (n = 86) and 1.8-mL (n = 47) tubes. Results Prothrombin time (PT) and fibrinogen values were slightly but significantly decreased in tubes with minimum than in those with optimal fill volume. The activated partial thromboplastin time (APTT) was slightly prolonged in tubes with minimum than in those with optimal fill volume, but the difference was not statistically significant. An identical trend was noted in separate analyses for the 2.7-mL and 1.8-mL tubes. Spearman's correlations between the two fill volumes were always >0.94 and bias was always within the quality specifications. Conclusions Blood drawing into Vacutainer® Citrate Plus tubes at minimum fill volume does not clinically bias routine coagulation testing.

Integrity of serum samples is changed by modified centrifugation conditions

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. Methods The study was done in four different periods (A, B, C and D) at different conditions: for 10, 5 and 7 (A, B and C, respectively) at 2876 × g, and 7 (D) min at 4141 × g. Sample quality was assessed as the proportion of samples with: (a) aspiration errors, (b) H index >0.5 g/L and (c) suppressed reports of potassium (K) due to hemolysis. TAT was calculated for emergency samples. The proportions of samples (a), (b) and (c) were compared according to period A. Results The number of aspiration errors was significantly higher in samples centrifuged at 2876 × g for 5 min (p = 0.021) and remained unchanged when centrifuged for 7 min (p = 0.066 and 0.177, for periods C and D, respectively). In periods B, C and D, the proportion of samples with hemolysis was higher than that in period A (p-values 0.039, 0.009 and 0.042, respectively). TAT differed between all periods (p < 0.001), with the lowest TAT observed for B and D. The lowest number of samples exceeding 60-min TAT was observed in period D (p = 0.011). Conclusions The integrity of serum samples is changed with different centrifugation conditions than those recommended. Our study showed that shorter centrifugation at higher force (7 min at 4141 × g) significantly decreases TAT, with unchanged proportion of samples with aspiration errors.

PREDICT: a checklist for preventing preanalytical diagnostic errors in clinical trials

Although the importance of guaranteeing a high level of preanalytical quality in routine diagnostic testing has already been largely acknowledged over the past decades, minor emphasis is currently being placed on the fact that accurate performance and standardization of many preanalytical activities are also necessary prerogatives of clinical trials. Reliable evidence exists that clear indications on how to manage the different preanalytical steps are currently lacking in many clinical trials protocols, nor have detailed authoritative documents been published or endorsed on this matter to the best of our knowledge. To fill this gap, the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for Preanalytical Phase (WG-PRE) will provide here a specific checklist for preventing preanalytical diagnostic errors in clinical trials (PREDICT), especially focused on covering the most important preanalytical aspects of blood sample management in clinical studies, and thus encompassing test selection, patient preparation, sample collection, management and storage, sample transportation, as well as specimen retrieval before testing. The WG-PRE members sincerely hope that these recommendations will provide a useful contribution for increasing the success rate in clinical trials.

Stability of refrigerated whole blood samples for osmotic fragility test

Background

The osmotic fragility test (OFT), conventionally used for assisting the diagnosis of many erythrocyte disorders, is a manual and time-consuming analysis not daily performed in many medical laboratories. This study was aimed at defining the stability of whole blood samples used for assessing erythrocyte osmotic resistance.

Methods

Twenty-one consecutive routine whole blood samples collected into 5.4 mg K2EDTA were tested immediately after collection (day 0) and at different time intervals afterward (day 1, 2, 3, 4, 7, 10 and 14) after storage at 4 °C. The OFT was performed with the Osmored Monotest (1.3% glycerol; Eurospital, Trieste, Italy). Results at the different time points were compared with those obtained at day 0 and with the reference change value (i.e., 33%).

Results

The median value of both hyperosmolar and hyposmolar resistance increased from baseline, reaching statistical significance at day 7 for hyperosmolar resistance and at day 1 for hyposmolar resistance, respectively. The median relative increase of hemolysis percentage values become greater than the reference change value at day 3 for hyposmolar resistance, while this limit was never overcome for hyperosmolar resistance. A significant inverse association was found between the mean increase in hyperosmolar resistance and the baseline value of hyperosmolar resistance (r = −0.92), mean corpuscular volume (MCV; r = −0.46) or mean corpuscular hemoglobin (MCH; r = −0.44), as well as between the mean increase in hyposmolar resistance and the baseline value of hyposmolar resistance (r = −0.86), or patient age (r = −0.56).

Conclusions

The sample stability seems critical for the OFT. Whole blood specimens should not be stored refrigerated at 4 °C for >2 days before testing.