The complexity of the preanalytical (PA) phase has precluded standardisation of PA processes, despite its impact on sample quality, laboratory efficiency, or patient & healthcare worker safety. The BD Laboratory Consulting Services™ Preanalytical Review audits PA procedures and practices in hospitals in different countries. Processes were assessed from storage of blood collection materials through specimen collection, transportation, processing of the samples and the resulting sample quality. By following the samples through the complete process, it was possible to link specific PA attributes to sample quality deficiencies.
Materials and methods:
A consistent method and data collection form were used for audits (N = 48) of all blood collection systems. Data were collected by observation of the PA phase. Sample quality was assessed for laboratory samples of the same type.
The PA phase was observed for 3597 blood collection tubes over 1350 collections. Sample quality was assessed for 8016 chemistry and 3532 coagulation tubes. For collections that resulted in hemolysed samples, 48% had prolonged use of tourniquet, 31% used catheters and for 38% the disinfectant was not allowed to dry. For serum samples with fibrin where the PA process had been observed, 26% had less than 30 minutes between collection and centrifugation and 81% had not been mixed. The following list gives the percentage of collections where a particular behaviour was observed, incorrect patient identification procedure, 56%; tubes labelled prior to collection 61%; coagulation tubes filled to less than 90% of tube volume 7%; gloves not worn 37%; incorrect activation of needle safety device 19%.
The BD Preanalytical Review standardised audit methodology allows comparison of results between departments and institutions. The prospective nature of the reviews permits identification of issues based on more data than from rejected samples alone and therefore affords a more complete understanding for those involved in the PA phase.
Preanalytical errors contribute to a large proportion of total laboratory errors. In order to achieve continuous laboratory improvement, it is important to focus on all phases of patient specimen testing i.e. preanalytical, analytical and post-analytical. With large variations in the way venous blood specimens are collected using diverse devices in the country, the effect of such practices on specimen quality is not known. The purpose of this study was to monitor fourteen specimen preanalytical quality indicators in order to compare the usage of evacuated blood collection devices with needle and syringe open collection using either disposable tubes or re-washed glass vials. The study involved 26638 patient specimens assessed over a period of 6 months. The results demonstrated that evacuated closed blood collection resulted in an approximate 100-fold reduction in the incidence of hemolysis in samples. Similarly, there was a 200-fold reduction in incidence of insufficient specimen quantity while using evacuated collection system. It was also found that incidence of specimen contamination, improper volume of sample collected, and specimen spillage was also lower when the evacuated collection system was used. Further, it was also observed that the facility with a laboratory information system demonstrated much lower specimen identification and related errors. The observed results clearly demonstrate that the usage of the evacuated blood collection system resulted in improvement of preanalytical specimen quality as compared to needle and syringe usage.
Preanalytical; Vacutainer; Hemolysis; Total quality; Needle and Syringe; Open collection
Critically ill adult patients often require multiple examinations in the hospital and need transport from one department to another, or even between hospitals. However, to date, no guidelines exist regarding optimum practices for transport of these fragile patients. We present recommendations for intrahospital transport of critically ill patients, excluding newborns, developed by an expert group of the French-Language Society of Intensive Care (Société de Réanimation de Langue Française (SRLF), the Société Française d’Anesthésie et de Réanimation (SFAR), and the Société Française de Médecine d’Urgence (SFMU). The recommendations cover five fields of application: epidemiology of adverse events; equipment, monitoring, and maintenance; preparation of patient before transport; human resources and training for caregivers involved in transport processes; and guidelines for planning, structure, and traceability of transport processes.
intrahospital transport; critical care; adults
Obesity and increases in body weight in adults are considered to be among the most important risk factors for type 2 diabetes. Low birth weight is also associated with a higher diabetes incidence. We aimed to examine to what extent the evolution of body shape, from childhood to adulthood, is related to incident diabetes in late adulthood.
RESEARCH DESIGN AND METHODS
Etude Epidemiologique de Femmes de la Mutuelle Générale de l'Education Nationale (E3N) is a cohort study of French women born in 1925–1950 and followed by questionnaire every 2 years. At baseline, in 1990, women were asked to report their current weight, height, and body silhouette at various ages. Birth weight was recorded in 2002. Cases of diabetes were self-reported or obtained by drug reimbursement record linkage and further validated.
Of the 91,453 women who were nondiabetic at baseline, 2,534 developed diabetes over the 15 years of follow-up. Birth weight and body silhouette at 8 years, at menarche, and in young adulthood (20–25 years) were inversely associated with the risk of diabetes, independently of adult BMI during follow-up (all Ptrend < 0.001). In mid-adulthood (35–40 years), the association was reversed, with an increase in risk related to a larger body silhouette. An increase in body silhouette from childhood to mid-adulthood amplified the risk of diabetes.
Low birth weight and thinness until young adulthood may increase the risk of diabetes, independently of adult BMI during follow-up. Young women who were lean children should be especially warned against weight gain.
Blood glucose concentrations are essential in defining diabetes mellitus. Recent guidelines advocate either of two discrete methods for sample collection and processing. One of these involves addition of glycolysis inhibitors, such as sodium fluoride–potassium oxalate (NaF–KOx) to sample collection tubes, whereas the other requires immediate refrigeration and sample separation.
To examine whether the choice of the preanalytical process has any impact on subsequent glucose determinations.
62 healthy men participated in the study during screening for diabetes. Paired venous blood samples were collected in a serum‐gel tube and a tube containing NaF–KOx (both Sarstedt, Leicester, UK). Serum was promptly separated from gel tube samples and refrigerated, whereas NaF–KOx samples were not separated until immediately before analysis. Glucose concentrations were determined using an Olympus AU 2700 analyser incorporating an automated hexokinase method.
Mean (95% CI) glucose concentration in serum‐gel tube samples was 5.2 mmol/l (5.0 to 5.4 mmol/l), whereas the concentration in tubes containing NaF–KOx was 4.9 mmol/l (4.8 to 5.1 mmol/l). A negative bias of 0.23 mmol/l (0.16 to 0.30 mmol/l) and relative negative bias of 4.7 % (3.2% to 6.3%) were observed for samples collected in NaF–KOx tubes, consistent with the combined effects of glycolysis and dilution.
Bias associated with the use of NaF–KOx tubes may have a significant impact on the prevalence of fasting hyperglycaemia, according to current diagnostic criteria. The small but significant difference between preanalytical processes should be considered when screening for the presence of diabetes mellitus.
A number of preanalytical activities strongly influence sample quality, especially those related to sample collection. Since blood drawing through intravenous catheters is reported as a potential source of erythrocyte injury, we performed a critical review and meta-analysis about the risk of catheter-related hemolysis.
Materials and methods:
We performed a systematic search on PubMed, Web of Science and Scopus to estimate the risk of spurious hemolysis in blood samples collected from intravenous catheters. A meta-analysis with calculation of Odds ratio (OR) and Relative risk (RR) along with 95% Confidence interval (95% CI) was carried out using random effect mode.
Fifteen articles including 17 studies were finally selected. The total number of patients was 14,796 in 13 studies assessing catheter and evacuated tubes versus straight needle and evacuated tubes, and 1251 in 4 studies assessing catheter and evacuated tubes versus catheter and manual aspiration. A significant risk of hemolysis was found in studies assessing catheter and evacuated tubes versus straight needle and evacuated tubes (random effect OR 3.4; 95% CI = 2.9–3.9 and random effect RR 1.07; 95% CI = 1.06–1.08), as well as in studies assessing catheter and evacuated tubes versus catheter and manual aspiration of blood (OR 3.7; 95% CI = 2.7–5.1 and RR 1.32; 95% CI = 1.24–1.40).
Sample collection through intravenous catheters is associated with significant higher risk of spurious hemolysis as compared with standard blood drawn by straight needle, and this risk is further amplified when intravenous catheter are associated with primary evacuated blood tubes as compared with manual aspiration.
hemolysis; preanalytical variability; catheters; meta-analysis
There is a long history of research into body fluid biomarkers in neurodegenerative and neuroinflammatory diseases. However, only a few biomarkers in CSF are being used in clinical practice. One of the most critical factors in CSF biomarker research is the inadequate powering of studies because of the lack of sufficient samples that can be obtained in single-center studies. Therefore, collaboration between investigators is needed to establish large biobanks of well-defined samples. Standardized protocols for biobanking are a prerequisite to ensure that the statistical power gained by increasing the numbers of CSF samples is not compromised by preanalytical factors. Here, a consensus report on recommendations for CSF collection and biobanking is presented, formed by the BioMS-eu network for CSF biomarker research in multiple sclerosis. We focus on CSF collection procedures, preanalytical factors, and high-quality clinical and paraclinical information. The biobanking protocols are applicable for CSF biobanks for research targeting any neurologic disease.
= clinically isolated syndrome;
= Expanded Disability Status Scale;
= immunoglobulin G;
= matrix-assisted laser desorption/ionization time-of-flight;
= multiple sclerosis;
= Multiple Sclerosis Functional Composite;
= secondary progressive multiple sclerosis.
Human biospecimens are subject to a number of different collection, processing, and storage factors that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research utilizing human tissues, it is critical that information regarding the handling of biospecimens be reported in a thorough, accurate, and standardized manner. The Biospecimen Reporting for Improved Study Quality recommendations outlined herein are intended to apply to any study in which human biospecimens are used. The purpose of reporting these details is to supply others, from researchers to regulators, with more consistent and standardized information to better evaluate, interpret, compare, and reproduce the experimental results. The Biospecimen Reporting for Improved Study Quality guidelines are proposed as an important and timely resource tool to strengthen communication and publications around biospecimen-related research and help reassure patient contributors and the advocacy community that the contributions are valued and respected.
OBJECTIVE: To evaluate the usefulness of a French-language version of the International Prostate Symptom Scale (I-PSS) by measuring, on this scale and on the quality of life index, the scores of patients with benign prostatic hyperplasia before and after prostate surgery. METHOD: The questionnaire was completed by 14 men, mostly between 60 and 80 years old, 24 hours before surgery and 1 month and 3 months after surgery. RESULTS: The French-language scale worked well. Scores changed from 19.1 before surgery to 7.5 3 months after surgery for prostate symptoms and from 8.5 to 4.5 for quality of life. CONCLUSION: This version of the questionnaire is a valid tool for evaluating prostate symptoms reported by French-speaking people.
A workshop sponsored by the National Cancer Institute and the US Food and Drug Administration addressed past lessons learned and ongoing challenges faced in biomarker development and drug and biomarker codevelopment. Participants agreed that critical decision points in the product life cycle depend on the level of understanding of the biology of the target and its interaction with the drug, the preanalytical and analytical factors affecting biomarker assay performance, and the clinical disease process. The more known about the biology and the greater the strength of association between an analytical signal and clinical result, the more efficient and less risky the development process will be. Rapid entry into clinical practice will only be achieved by using a rigorous scientific approach, including careful specimen collection and standardized and quality-controlled data collection. Early interaction with appropriate regulatory bodies will ensure studies are appropriately designed and biomarker test performance is well characterized.
Human biospecimens are subject to a number of different collection, processing, and storage factors that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research utilizing human tissues it is critical that information regarding the handling of biospecimens be reported in a thorough, accurate, and standardized manner. The Biospecimen Reporting for Improved Study Quality (BRISQ) recommendations outlined herein are intended to apply to any study in which human biospecimens are used. The purpose of reporting these details is to supply others, from researchers to regulators, with more consistent and standardized information to better evaluate, interpret, compare, and reproduce the experimental results. The BRISQ guidelines are proposed as an important and timely resource tool to strengthen communication and publications around biospecimen-related research and help reassure patient contributors and the advocacy community that the contributions are valued and respected.
Biospecimen quality is affected by a number of preanalytical factors that may or may not be obvious to the investigator. These factors are introduced through multiple biospecimen collection, processing and storage procedures which can differ dramatically within and between medical institutions and biorepositories. Biospecimen Science is the emerging field of study that is attempting to quantify and control such variability. A variety of efforts are under way around the world to establish research programs, evidence-based biospecimen protocols, and standards to improve the overall quality of biospecimens for research.
Biospecimen science; Biospecimen research; Biospecimen; Best practices
The most critical performance indicator for medical laboratories is the delivery of accurate test results. In any laboratory, there is always the possibility that random or systematic errors may occur and place human health and welfare at risk. Laboratory quality assurance programmes continue to drive improvements in analytical accuracy. The most rigorously scrutinised data on laboratory errors, which come from transfusion medicine, reveal that the incidence of analytical errors has fallen to levels where most of the residual risk is now found in preanalytical links in the chain from patient to result, particularly activities associated with ordering of tests and sample collection. This insight is important for genetic testing because, like pretransfusion testing of patients with unknown blood groups, a substantial proportion of genotyping results cannot be immediately verified. An increasing number of clinical decisions, associated personal and social choices, and legal outcomes are now influenced by genetic test results in the absence of other confirmatory data. An incorrect test result may lead to unnecessary and irreversible interventions, which may in themselves have associated risks for the patient, inaccurate risk assessment regarding the disease, missed opportunities for disease prevention or even wrongful conviction in a court of law. Unfortunately, there is limited information available about the risk of preanalytical errors associated with, and few published guidelines regarding, sample collection for genetic testing. The growing number and range of important decisions made on the basis of genetic findings warrant a reappraisal of current standards to minimise risks in genetic testing.
Genetic testing; medical errors; risk management; standards; quality, genetics; DNA; general; ethics; cancer genetics
Peptide-based mass spectrometry approaches, such as multiple reaction monitoring, provide a powerful means to measure candidate protein biomarkers in plasma. A potential confounding problem is the effect of preanalytical variables, which may affect the integrity of proteins and peptides. Although some blood proteins undergo rapid physiological proteolysis ex vivo, the stability of most plasma proteins to preanalytical variables remains largely unexplored. We applied liquid chromatography-tandem mass spectrometry shotgun proteomics and multiple reaction monitoring analyses to characterize the stability of proteins at the peptide level in plasma. We systematically evaluated the effects of delay in plasma preparation at different temperatures, multiple freeze-thaw cycles and erythocyte hemolysis on peptide and protein inventories in prospectively collected human plasma. Time course studies indicated few significant changes in peptide and protein identifications, semitryptic peptides and methionine-oxidized peptides in plasma from blood collected in EDTA plasma tubes and stored for up to a week at 4 °C or room temperature prior to plasma isolation. Similarly, few significant changes were observed in similar analyses of plasma subjected to up to 25 freeze-thaw cycles. Hemolyzed samples produced no significant differences beyond the presence of hemoglobin proteins. Finally, paired comparisons of plasma and serum samples prepared from the same patients also yielded few significant differences, except for the depletion of fibrinogen in serum. Blood proteins thus are broadly stable to preanalytical variables when analyzed at the peptide level. Collection protocols to generate plasma for multiple reaction monitoring-based analyses may have different requirements than for other analyses directed at intact proteins.
Le syndrome de Fahr est une entité anatomo-clinique rare, caractérisée par des calcifications intracérébrales bilatérales et symétriques, localisées dans les noyaux gris centraux, le plus souvent associées à des troubles du métabolisme phosphocalcique. L'hypoparathyroïdie, primitive ou postopératoire, est l'anomalie la plus classique. L'hyperparathyroïdie est exceptionnellement rapportée comme cause du syndrome de Fahr. Nous rapportons le cas d'une fille de 17 ans suivie depuis l’âge de 12 ans pour une épilepsie avec la notion d'un retard mental depuis l'enfance, qui a présenté un syndrome confusionnel révélant un syndrome de Fahr avec la particularité de l'existence d'une hyperparathyroïdie.
Syndrome confusionnel; syndrome de Fahr; retard mental; épilepsie; hyperparathyroïdie; confusional syndrome; Fahr syndrome; mental retardation; epilepsy; hyperparathyroidism
Studies about vitamin D [25(OH)D] stability in plasma are limited and preanalytical variables such as tube type may affect results. We aimed to evaluate effect of storage conditions, sample type and some preanalytical variables on vitamin D concentration.
Materials and methods:
Blood samples from 15 healthy subjects were centrifuged at different temperatures and stored under different conditions. Serum and plasma 25(OH)D difference, effect of centrifugation temperature and common storage conditions were investigated.
There was no difference between serum and plasma vitamin D concentration. Centrifugation temperature had no impact on vitamin D concentration. 25(OH)D is stable under common storage conditions: 4 hours at room temperature, 24 hours at 2–8 °C, 7 days at −20 °C, 3 months at −80 °C.
Vitamin D does not require any special storage conditions and refrigeration. Both serum and plasma can be used for measurement.
centrifugation; temperature; stability; vitamin D; preanalytical phase
Two US randomized trials found a lower incidence of type 2 diabetes among women treated by menopausal hormone therapy (MHT) with oral conjugated equine estrogen combined with medroxyprogesterone acetate. The purpose of this study was to evaluate the influence of various MHTs, according to their formulation and route of administration, on new-onset diabetes in a cohort of postmenopausal French women.
The association between MHT use and new-onset diabetes was investigated by Cox regression analysis in 63,624 postmenopausal women of the French E3N cohort. Cases of diabetes were identified through self-report or drug reimbursement record linkage, and further validated.
1220 new-onset diabetes cases were validated. We observed a lower risk of new-onset diabetes among women having ever used MHT (Hazard ratio: HR=0.82 [0.72 – 0.93]), compared to MHT never users. Adjustment for BMI during follow-up rather than baseline BMI did not substantially modify this association. An oral route of estrogen administration was associated with a greater decrease in diabetes risk than a cutaneous route (HR=0.68 [0.55–0.85] vs 0.87 [0.75–1.00], P for homogeneity=0.028). When further taking into account the type of progestagen used in combined MHT, we were not able to show significant differences between progestagens.
MHT appeared to be associated with a lower risk of new-onset diabetes. This relation was not mediated by changes in BMI. Further studies are needed to confirm the stronger effect of oral administration of estrogen compared to cutaneous administration.
Adult; Aged; Diabetes Mellitus; epidemiology; Estrogens, Conjugated (USP); therapeutic use; Female; Hormone Replacement Therapy; Humans; Medroxyprogesterone Acetate; therapeutic use; Middle Aged; Postmenopause; Proportional Hazards Models; Questionnaires; Randomized Controlled Trials as Topic; adult diabetes; postmenopause; menopausal hormone therapy; cohort study
Aim: This study was conducted to evaluate the frequency of the preanalytical errors occurring in a haematology laboratory.
Material and Methods: A retrospective study was conducted by collecting and analyzing data in duration of one year in the haematology section of the laboratory. Data for all the preanalytical variables according to the predefined categories were scanned. Both IPD and OPD patients were segregated.
Result: A total of 135808 samples were received in haematology lab during this period, out of which in 1339 samples, preanalytical errors were found, which approximately constituted 1 % of all samples.
Conclusion: Highest number of samples were rejected due to misidentification, that is 0.35 % and least number were rejected due to dilution of the samples, that is 0.04 %.
Pre–analytical errors; Haematology; Laboratory
La thrombasthenie de Glanzmann est une anomalie plaquettaire qualitative, à transmission autosomale récessive, due à un déficit en glycoprotéine IIb/IIIa (GPIIb/IIIa), avec un défaut d'agrégation plaquettaire. Il en résulte une perturbation de l'hémostase primaire, à l'origine d'hémorragie plus ou mois importantes. Nous rapportons l'observation de N.A, âgée de 32 ans, suivie depuis l'enfance pour maladie de Glanzmann, troisième pare, avec deux accouchements par voie basse et une césarienne programmée, compliqués tous les trois par hémorragie de délivrance, jugulée avec succés. La grossesse chez une patiente thrombo-asthenique reste rare, peu de cas jusqu'à présent, sont décrits. A travers cette observation, et à la lumière d'une revue de la littérature, nous allons essayer surtout, de mettre le point sur la prise en charge de cette association délicate, qui met en jeu, à chaque fois, le pronostic vital maternel.
Thrombasthénie de Glanzmann; grossesse; complications; Maroc
Reliability cannot be achieved in a clinical laboratory through the control of accuracy in the analytical phase of the testing process alone. Indeed a "mistake" can be defined as any defect occuring during the testing process. In the analysis of clinical specimens, there are many possible preanalytical sources of error. Therefore, the application of quality system to laboratory testing requires total quality management throughout the laboratory process, including the preanalytical and postanalytical phases. ISO 9002:1994 is a model for quality assurance in production, installation, and servicing, which includes a number of clauses providing guidance for implementation in clinical laboratories. Our laboratory at King Chulalongkorn Memorial Hospital, the largest Thai Red Cross Society hospital, is the first clinical laboratory in Thailand with ISO 9002:1994 certified for the whole unit.
In this study, we evaluated the frequency and types of preanalytical mistakes found in our laboratory, by monitoring specimens requested for laboratory analyses from both in-patient and out-patient divisions for 6 months.
Among a total of 935,896 specimens for 941,902 analyses, 1,048 findings were confirmed as preanalytical mistakes; this was a relative frequency of 0.11 % (1,048/935,896). A total of 1,240 mistakes were identified during the study period. Comparing the preanalytical mistakes to other mistakes in the laboratory process monitored in the same setting and period, the distribution of mistakes was: preanalytical 84.52 % (1,048 mistakes), analytical 4.35 % (54 mistakes), and postanalytical 11.13 % (138 mistakes). Of 1,048 preanalytical mistakes, 998 (95.2%) originated in the care units. All preanalytical mistakes, except for 12 (1.15 %) relating to the laboratory barcode reading machine, were due to human error.
Most mistakes occurred before samples were analysed, either during sampling or preparation for analysis. This suggests that co-operation with clinicians and personnel outside the laboratory is still the key to improvement of laboratory quality.
Measurement of peripheral blood cytokines and other immunomodulatory proteins is a useful and popular tool for assessing human immune responses to a wide range of assaults. A common challenge in this work is obtaining fresh, high-quality samples and limiting the time between blood collection and the separation of plasma or serum from cells. In this study we sought to determine the effect of sample age at the time of processing on the measured levels of 41 soluble immune mediators. Two cohorts were examined: healthy lab donors and trauma patients, who have significant immune perturbation. Whole-blood samples were aliquoted, and plasma was isolated, at days 0, 1, 2, and 3 after collection. Multiplexing techniques were used to measure protein concentrations, and general estimating equations were used to determine if there was a significant change over time. Over the 3-day period examined, only 15 of the 41 proteins showed no significant change in either cohort. Among the remaining proteins both increases and decreases were observed, with changes ranging from 2.4% per day to 325% per day. Proteins with significant changes in one cohort did not always show significant changes in the other group. These results support the need to separate plasma or serum from whole blood as quickly as possible and/or to standardize the length of time to processing within a given study of peripheral blood protein concentrations. When this is not possible, care should be taken to account for differences due to sample age.
In sub-Saharan Africa, unacceptably high rates of mortality amongst women and children continue to persist. The emergence of research employing new genomic technologies is advancing knowledge on cause of disease. This review aims to identify birth cohort studies conducted in sub-Saharan Africa and to consider their suitability as a platform to support genetic epidemiological studies.
A systematic literature review was conducted to identify birth cohort studies in sub-Saharan Africa across the following databases: MEDLINE, EMBASE, AFRO and OpenSIGLE. A total of 8110 papers were retrieved. Application of inclusion/exclusion criteria retained only 189 papers, of which 71 met minimum quality criteria and were retained for full text analysis.
The search revealed 28 birth cohorts: 14 of which collected biological data, 10 collected blood samples and only one study collected DNA for storage. These studies face many methodological challenges: notably, high rates of attrition and lack of funding for several rounds of study follow up. Population-based ‘biobanks’ have emerged as a major approach to harness genomic technologies in health research and yet the sub-Saharan African region still awaits large scale birth cohort biobanks collecting DNA and associated health and lifestyle data.
Investment in this field, together with related endeavours to foster and develop research capacity for these studies, may lead to an improved understanding of the determinants of intrauterine growth and development, birth outcomes such as prematurity and low birth weight, the links between maternal and infant health, survival of infectious diseases in the first years of life, and response to vaccines and antibiotic treatment.
Long-term storage of biological materials is a critical component of any epidemiological study. In designing specimen repositories, efforts need to balance future needs for samples with logistical constraints necessary to process and store samples in a timely fashion.
In the Norwegian Mother and Child Cohort Study (MoBa), the Biobank was charged with long-term storage of more than 380,000 biological samples from pregnant women, their partners and their children for up to 100 years.
Biological specimens include whole blood, plasma, DNA and urine; samples are collected at 50 hospitals in Norway. All samples are sent via ordinary mail to the Biobank in Oslo where the samples are registered, aliquoted and DNA extracted. DNA is stored at −20 °C while whole blood, urine and plasma are stored at − 80 °C.
As of July 2006, over 227,000 sample sets have been collected, processed and stored at the Biobank. Currently 250–300 sets are received daily. An important part of the Biobank is the quality control program.
With the unique combination of biological specimens and questionnaire data, the MoBa Study will constitute a resource for many future investigations of the separate and combined effects of genetic, environmental factors on pregnancy outcome and on human morbidity, mortality and health in general.
Automation; Biobank; Birth Cohort Study; DNA; Plasma; Quality Control
Exhaled breath condensate (EBC) is thought to contain substances of the lower airway epithelial lining fluid (ELF) aerosolized by turbulent flow. However, contamination by saliva may affect the EBC when collected orally.
The purpose of this study was to compare the cytokine expression levels in EBC with those in saliva, and to clarify the influence of saliva on cytokine measurements of EBC.
EBC and saliva samples were obtained from 10 adult subjects with stable asthma. To estimate differences in the contents of substances between EBC and saliva, the total protein concentration of each sample was measured. Further, we also measured the total protein concentration of ELF obtained from another patient group with suspected lung cancer using a micro sampling probe during bronchoscopic examination and roughly estimated the dilution of EBC by comparing the total protein concentration of EBC and ELF from those two patient groups. The cytokine expression levels of EBC and saliva from asthmatic group were assessed by a cytokine protein array.
The mean total protein concentrations in EBC, saliva and ELF were 4.6 μg/ml, 2,398 μg/ml and 14,111 μg/ml, respectively. The dilution of EBC could be estimated as 1:3000. Forty cytokines were analyzed by a cytokine protein array and each cytokine expression level of EBC was found to be different from that of saliva. Corrected by the total protein concentration, all cytokine expression levels of EBC were significantly higher than those of saliva.
These results suggest that the salivary influence on the cytokine assessment in EBC may be negligible.
asthma; cytokine; chemokine; growth factor; epithelial lining fluid
Contents of the epithelial lining fluid (ELF) of the bronchi are of central interest in lung diseases, acute lung injury and pharmacology. The most commonly used technique broncheoalveolar lavage is invasive and may cause lung injury. Microdialysis (MD) is a method for continuous sampling of extracellular molecules in the immediate surroundings of the catheter. Urea is used as an endogenous marker of dilution in samples collected from the ELF. The aim of this study was to evaluate bronchial MD as a continuous monitor of the ELF.
Microdialysis catheters were introduced into the right main stem bronchus and into the right subclavian artery of five anesthetized and normoventilated pigs. The flowrate was 2 μl/min and the sampling interval was 60 minutes. Lactate and fluorescein-isothiocyanate-dextran 4 kDa (FD-4) infusions were performed to obtain two levels of steady-state concentrations in blood. Accuracy was defined as [bronchial-MD] divided by [arterial-MD] in percent. Data presented as mean ± 95 percent confidence interval.
The accuracy of bronchial MD was calculated with and without correction by the arteriobronchial urea gradient. The arteriobronchial lactate gradient was 1.2 ± 0.1 and FD-4 gradient was 4.0 ± 1.2. Accuracy of bronchial MD with a continuous lactate infusion was mean 25.5% (range 5.7–59.6%) with a coefficient of variation (CV) of 62.6%. With correction by the arteriobronchial urea gradient accuracy was mean 79.0% (57.3–108.1%) with a CV of 17.0%.
Urea as a marker of catheter functioning enhances bronchial MD and makes it useful for monitoring substantial changes in the composition of the ELF.