Influence of a light meal on routine haematological tests

Introduction Patient-related variables such as physical exercise stress and fasting status are Important sources of variability in laboratory testing However no clear indications about tasting requirements exist for routine haematological tests nor has the influence of meals been assessed Methods We studied 17 healthy volunteers who consumed a light meal containing a standardized amount of carbohydrates, protein and lipids Blood was taken for routine haematological tests before the meal and 1 2 and 4 hours thereafter Results One hour after the meal neutrophil count and mean corpuscular haemoglobin (MHC) increased significantly whereas lymphocyte and monocyte counts red blood cell distribution width, haematocrit, and mean corpuscular volume decreased significantly A clinically significant variation was only observed for lymphocytes Two hours after the meal a significant increase was observed for neutrophils and MCH whereas lymphocytes eosinophils, haemoglobin and haematocrit decreased significantly Clinically significant variations were recorded for lymphocytes red blood cells (RBC), haemoglobin haematocrit and MCH Four hours after the meal MCH was significantly increased while lymphocytes eosinophils, RBC, haemoglobin and haematocrit were significantly decreased Clinically significant variations were recorded for neutrophils eosinophils RBC hematocrit and MCH Conclusion The significant variation of several haematological parameters after a light meal demonstrates that the fasting time needs to be carefully considered in order to interpret the results of haematological tests correctly

Sources of pre-analytical variations in yield of DNA extracted from blood samples: analysis of 50,000 DNA samples in EPIC.

The European Prospective Investigation into Cancer and nutrition (EPIC) is a long-term, multi-centric prospective study in Europe investigating the relationships between cancer and nutrition. This study has served as a basis for a number of Genome-Wide Association Studies (GWAS) and other types of genetic analyses. Over a period of 5 years, 52,256 EPIC DNA samples have been extracted using an automated DNA extraction platform. Here we have evaluated the pre-analytical factors affecting DNA yield, including anthropometric, epidemiological and technical factors such as center of subject recruitment, age, gender, body-mass index, disease case or control status, tobacco consumption, number of aliquots of buffy coat used for DNA extraction, extraction machine or procedure, DNA quantification method, degree of haemolysis and variations in the timing of sample processing. We show that the largest significant variations in DNA yield were observed with degree of haemolysis and with center of subject recruitment. Age, gender, body-mass index, cancer case or control status and tobacco consumption also significantly impacted DNA yield. Feedback from laboratories which have analyzed DNA with different SNP genotyping technologies demonstrate that the vast majority of samples (approximately 88%) performed adequately in different types of assays. To our knowledge this study is the largest to date to evaluate the sources of pre-analytical variations in DNA extracted from peripheral leucocytes. The results provide a strong evidence-based rationale for standardized recommendations on blood collection and processing protocols for large-scale genetic studies.

Pre-analytical and methodological challenges in red blood cell microparticle proteomics.

Microparticles are phospholipid vesicles shed mostly in biological fluids, such as blood or urine, by various types of cells, such as red blood cells (RBCs), platelets, lymphocytes, endothelial cells. These microparticles contain a subset of the proteome of their parent cell, and their ready availability in biological fluid has raised strong interest in their study, as they might be markers of cell damage. However, their small size as well as their particular physico-chemical properties makes them hard to detect, size, count and study by proteome analysis. In this review, we report the pre-analytical and methodological caveats that we have faced in our own research about red blood cell microparticles in the context of transfusion science, as well as examples from the literature on the proteomics of various kinds of microparticles.

Biomarker analysis of stored blood products: emphasis on pre-analytical issues.

Millions of blood products are transfused every year; many lives are thus directly concerned by transfusion. The three main labile blood products used in transfusion are erythrocyte concentrates, platelet concentrates and fresh frozen plasma. Each of these products has to be stored according to its particular components. However, during storage, modifications or degradation of those components may occur, and are known as storage lesions. Thus, biomarker discovery of in vivo blood aging as well as in vitro labile blood products storage lesions is of high interest for the transfusion medicine community. Pre-analytical issues are of major importance in analyzing the various blood products during storage conditions as well as according to various protocols that are currently used in blood banks for their preparations. This paper will review key elements that have to be taken into account in the context of proteomic-based biomarker discovery applied to blood banking.

Development of muliplexed analytical methods based on bioluminescent whole-cell biosensors

The subject of this Ph.D. research thesis is the development and application of multiplexed analytical methods based on bioluminescent whole-cell biosensors. One of the main goals of analytical chemistry is multianalyte testing in which two or more analytes are measured simultaneously in a single assay. The advantages of multianalyte testing are work simplification, high throughput, and reduction in the overall cost per test. The availability of multiplexed portable analytical systems is of particular interest for on-field analysis of clinical, environmental or food samples as well as for the drug discovery process. To allow highly sensitive and selective analysis, these devices should combine biospecific molecular recognition with ultrasensitive detection systems. To address the current need for rapid, highly sensitive and inexpensive devices for obtaining more data from each sample,genetically engineered whole-cell biosensors as biospecific recognition element were combined with ultrasensitive bioluminescence detection techniques. Genetically engineered cell-based sensing systems were obtained by introducing into bacterial, yeast or mammalian cells a vector expressing a reporter protein whose expression is controlled by regulatory proteins and promoter sequences. The regulatory protein is able to recognize the presence of the analyte (e.g., compounds with hormone-like activity, heavy metals…) and to consequently activate the expression of the reporter protein that can be readily measured and directly related to the analyte bioavailable concentration in the sample. Bioluminescence represents the ideal detection principle for miniaturized analytical devices and multiplexed assays thanks to high detectability in small sample volumes allowing an accurate signal localization and quantification. In the first chapter of this dissertation is discussed the obtainment of improved bioluminescent proteins emitting at different wavelenghts, in term of increased thermostability, enhanced emission decay kinetic and spectral resolution. The second chapter is mainly focused on the use of these proteins in the development of whole-cell based assay with improved analytical performance. In particular since the main drawback of whole-cell biosensors is the high variability of their analyte specific response mainly caused by variations in cell viability due to aspecific effects of the sample’s matrix, an additional bioluminescent reporter has been introduced to correct the analytical response thus increasing the robustness of the bioassays. The feasibility of using a combination of two or more bioluminescent proteins for obtaining biosensors with internal signal correction or for the simultaneous detection of multiple analytes has been demonstrated by developing a dual reporter yeast based biosensor for androgenic activity measurement and a triple reporter mammalian cell-based biosensor for the simultaneous monitoring of two CYP450 enzymes activation, involved in cholesterol degradation, with the use of two spectrally resolved intracellular luciferases and a secreted luciferase as a control for cells viability. In the third chapter is presented the development of a portable multianalyte detection system. In order to develop a portable system that can be used also outside the laboratory environment even by non skilled personnel, cells have been immobilized into a new biocompatible and transparent polymeric matrix within a modified clear bottom black 384 -well microtiter plate to obtain a bioluminescent cell array. The cell array was placed in contact with a portable charge-coupled device (CCD) light sensor able to localize and quantify the luminescent signal produced by different bioluminescent whole-cell biosensors. This multiplexed biosensing platform containing whole-cell biosensors was successfully used to measure the overall toxicity of a given sample as well as to obtain dose response curves for heavy metals and to detect hormonal activity in clinical samples (PCT/IB2010/050625: “Portable device based on immobilized cells for the detection of analytes.” Michelini E, Roda A, Dolci LS, Mezzanotte L, Cevenini L , 2010). At the end of the dissertation some future development steps are also discussed in order to develop a point of care (POCT) device that combine portability, minimum sample pre-treatment and highly sensitive multiplexed assays in a short assay time. In this POCT perspective, field-flow fractionation (FFF) techniques, in particular gravitational variant (GrFFF) that exploit the earth gravitational field to structure the separation, have been investigated for cells fractionation, characterization and isolation. Thanks to the simplicity of its equipment, amenable to miniaturization, the GrFFF techniques appears to be particularly suited for its implementation in POCT devices and may be used as pre-analytical integrated module to be applied directly to drive target analytes of raw samples to the modules where biospecifc recognition reactions based on ultrasensitive bioluminescence detection occurs, providing an increase in overall analytical output.

Effect of temperature and storage time on cellular analysis of fresh pleural fluid samples

L. Antonangelo, F. S. Vargas, M. M. P. Acencio, A. P. Cora, L. R. Teixeira, E. H. Genofre and R. K. B. Sales Effect of temperature and storage time on cellular analysis of fresh pleural fluid samples Objective: Despite the methodological variability in preparation techniques for pleural fluid cytology, it is fundamental that the cells should be preserved, permitting adequate morphological classification. We evaluated numerical and morphological changes in pleural fluid specimens processed after storage at room temperature or under refrigeration. Methods: Aliquots of pleural fluid from 30 patients, collected in ethylenediaminetetraacetic acid-coated tubes and maintained at room temperature (21 degrees C) or refrigeration (4 degrees C) were evaluated after 2 and 6 hours and 1, 2, 3, 4, 7 and 14 days. Evaluation of cytomorphology and global and percentage counts of leucocytes, macrophages and mesothelial cells were included. Results: The samples had quantitative cellular variations from day 3 or 4 onwards, depending on the storage conditions. Morphological alterations occurred earlier in samples maintained at room temperature (day 2) than in those under refrigeration (day 4). Conclusions: This study confirms that storage time and temperature are potential pre-analytical causes of error in pleural fluid cytology.

Variation in pre-PCR processing of FFPE samples leads to discrepancies in BRAF and EGFR mutation detection: a diagnostic RING trial.

AIMS: Mutation detection accuracy has been described extensively; however, it is surprising that pre-PCR processing of formalin-fixed paraffin-embedded (FFPE) samples has not been systematically assessed in clinical context. We designed a RING trial to (i) investigate pre-PCR variability, (ii) correlate pre-PCR variation with EGFR/BRAF mutation testing accuracy and (iii) investigate causes for observed variation. METHODS: 13 molecular pathology laboratories were recruited. 104 blinded FFPE curls including engineered FFPE curls, cell-negative FFPE curls and control FFPE tissue samples were distributed to participants for pre-PCR processing and mutation detection. Follow-up analysis was performed to assess sample purity, DNA integrity and DNA quantitation. RESULTS: Rate of mutation detection failure was 11.9%. Of these failures, 80% were attributed to pre-PCR error. Significant differences in DNA yields across all samples were seen using analysis of variance (p

Influences of sex and age on biological rhythms of serum lipids and lipoproteins

Background: Few studies have evaluated seasonal variations of biochemical parameters routinely analyzed in clinical laboratories. Rhythmic patterns for lipids and lipoproteins have been demonstrated and have been the object of research, mainly because of their demonstrated association with coronary artery disease. This study evaluated the occurrence of biological rhythms on serum lipids and lipoproteins and the effects of sex and age on the rhythms in a Brazilian hospital outpatient population. Methods: Retrospective laboratory study was carried out to evaluate the results of total cholesterol (TC), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C) and triglycerides (TG), from individuals registered at a university referral hospital over 8years. The studied population was composed of individuals of both sexes and all ages totaling 38,579 participants and 301,934 measurements. Statistical analyses were carried out using the SAS program and the temporal analysis used the Cosinor method. Results: TG rhythm was present only in females. All other parameters were equally rhythmic in both sexes. Regarding age, HDL-C presented rhythms in all age groups, but TC and LDL-C showed seasonality only for those > 13years, TG did not present rhythms in all age groups. Conclusion: Effects of sex and age on biological rhythms detected in TC, LDL-C and HDL-C should be considered a significant cause of pre-analytical variation in these laboratory tests. (C) 2009 Elsevier B.V. All rights reserved.

Consistent Alterations of Circulating Matrix Metalloproteinases Levels in Untreated Hypertensives and in Spontaneously Hypertensive Rats: A Relevant Pharmacological Target

Inconsistent matrix metalloproteinases (MMPs) levels have been reported in hypertension, with higher, similar and lower MMPs levels reported in hypertensives compared with normotensives. Differences between studies may reflect lack of control of drug effects, accompanying diseases and pre-analytical issues. We compared MMP-2, MMP-8 and MMP-9 levels in 38 untreated hypertensive patients (with no other diseases) with those found in 33 normotensive controls. We also studied endogenous MMPs inhibitors (TIMP-1, TIMP-2 and alpha-2-macroglobulin-A2M). Additionally, we assessed MMPs and A2M levels in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. We hypothesized that similar MMPs/endogenous inhibitors` profiles would be found in this animal model of hypertension and in clinical hypertension. MMPs, TIMPs and A2M were measured in plasma samples with commercially available ELISA and gelatin zymography. We found unaltered MMP-2, MMP-8, TIMP-1, TIMP-2 and A2M levels in hypertension. However, hypertensives had higher MMP-9 levels and MMP-9/A2M ratios than normotensives. Moreover, while we found similar MMP-2 and A2M levels in SHR and WKY rats, we found higher MMP-9 levels and MMP-9/A2M ratios in SHR versus WKY rats. These findings show consistent abnormal net plasma MMP-9 (but not MMP-2) activity in clinical and experimental hypertension. These parallel alterations in clinical hypertension and in SHR suggest an important role for MMPs in hypertension. While MMPs may be a relevant pharmacological target, antihypertensive drugs that down-regulate MMPs may offer advantages in the management of this disease.

Bridging environmental conflicts with social metabolism : forestry expansion and socioeconomic change

Dissertação apresentada para obtenção do Grau de Doutor em Ciências do Ambiente, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Erros pré-analíticos em anatomia patológica : prevalência, caracterização e consequências para a segurança do doente

RESUMO - A literatura disponível revela que a maioria dos erros relacionados com os exames anatomopatológicos ocorre na fase pré-analítica. Existem alguns estudos que quantificam e caracterizam estes erros mas, não foram encontrados artigos publicados sobre o tema em hospitais portugueses. Foi objetivo deste estudo determinar qual a prevalência e características dos erros pré-analíticos em amostras anatomopatológicas e as suas consequências para a segurança do doente. Analisaram-se 10574 casos de exames anatomopatológicos, de cinco hospitais da região de Lisboa e Vale do Tejo. Os serviços de anatomia patológica registaram e caracterizaram, durante vinte dias, erros detetados nas amostras anatomopatológicas com origem nos serviços requisitantes. Posteriormente os hospitais foram caracterizados quanto aos procedimentos relativos à fase pré-analítica. A prevalência de erros aferida foi de 3,1% (n=330), com um intervalo de confiança a 95% compreendido entre os valores 2,8% e 3,5%. Para além destes resultados destacam-se os seguintes pontos: i. As amostras histológicas têm 4,1% de prevalentes e as de citologia 0,9%; ii. Foram registados erros em 2,6% das requisições e em 1,5% dos contentores com as amostras; iii. A aceitação dos casos com erro é a ação mais frequente (66,9%), seguida pela devolução (24,4%) e retenção (8,7%); iv. Os hospitais com sistemas de notificação de erros e normas escritas para aceitação de amostras têm menor prevalência de erros; v. O impacte dos erros detetados na segurança dos doentes é difícil de determinar, sendo que os mais críticos relacionam-se com amostras devolvidas a fresco, meio de colheita inadequado ou com amostras danificadas. Este estudo permitiu determinar a prevalência e caracterizar os erros pré-analíticos envolvendo amostras anatomopatológicas em hospitais portugueses. Reflete a dimensão atual do problema e efetua recomendações para a sua mitigação. A prevalência de erros encontrada é inferior às publicadas em estudos semelhantes.

O erro na fase pré-analítica : amostras não conformes versus procedimentos

RESUMO: As Análises Clínicas são um precioso elemento entre os meios complementares de diagnóstico e terapêutica permitindo uma enorme panóplia de informações sobre o estado de saúde de determinado utente. O objetivo do laboratório é fornecer informação analítica sobre as amostras biológicas, sendo esta caracterizada pela sua fiabilidade, relevância e facultada em tempo útil. Assim, tratando-se de saúde, e mediante o propósito do laboratório, é notória a sua importância, bem como, a dos fatores associados para o cumprimento do mesmo. O bom desenrolar do ciclo laboratorial, compreendido pelas fases pré-analítica, analítica e pós-analítica é crucial para que o objetivo do laboratório seja cumprido com rigor e rapidez. O presente trabalho “O Erro na Fase Pré-Analítica: Amostras Não Conformes versus Procedimentos”, enquadrado no mestrado de Qualidade e Organização no Laboratório de Análises Clínicas, pretendeu enfatizar a importância da fase pré- analítica, sendo ela apontada como a primordial em erros que acabam por atrasar a saída de resultados ou por permitir que os mesmos não sejam fidedignos como se deseja, podendo acarretar falsos diagnósticos e decisões clínicas erradas. Esta fase, iniciada no pedido médico e finalizada com a chegada das amostras biológicas ao laboratório está entregue a uma diversidade de procedimentos que acarretam, por si só, uma grande diversidade de intervenientes, para além de uma variabilidade de factores que influenciam a amostra e seus resultados. Estes fatores, que podem alterar de algum modo a “veracidade” dos resultados analíticos, devem ser identificados e tidos em consideração para que estejamos convitos que os resultados auxiliam diagnósticos precisos e uma avaliação correta do estado do utente. As colheitas que por quaisquer divergências não originam amostras que cumpram o objectivo da sua recolha, não estando por isso em conformidade com o pretendido, constituem uma importante fonte de erro para esta fase pré-analítica. Neste estudo foram consultados os dados relativos a amostras de sangue e urina não conformes detetadas no laboratório, em estudo, durante o 1º trimestre de 2012, para permitir conhecer o tipo de falhas que acontecem e a sua frequência. Aos Técnicos de Análises Clínicas, colaboradores do laboratório, foi-lhes pedido que respondessem a um questionário sobre os seus procedimentos quotidianos e constituíssem, assim, a população desta 2ª parte do projeto. Preenchido e devolvido de forma anónima, este questionário pretendeu conhecer os procedimentos na tarefa de executar colheitas e, hipoteticamente, confrontá-los com as amostras não conformes verificadas. No 1ºsemestre de 2012 e num total de 25319 utentes registaram-se 146 colheitas que necessitaram de repetição por se verificarem não conformes. A “amostra não colhida” foi a não conformidade mais frequente (50%) versus a “má identificação” que registou somente 1 acontecimento. Houve ainda não conformidades que não se registaram como “preparação inadequada” e “amostra mal acondicionada”. Os técnicos revelaram-se profissionais competentes, conhecedores das tarefas a desempenhar e preocupados em executá-las com qualidade. Eliminar o erro não estará, seguramente, ao nosso alcance porém admitir a sua presença, detetá-lo e avaliar a sua frequência fará com que possamos diminuir a sua existência e melhorar a qualidade na fase pré-analítica, atribuindo-lhe a relevância que desempenha no processo laboratorial.-----------ABSTRACT:Clinical analyses are a precious element among diagnostic and therapeutic tests as they allow an enormous variety of information on the state of health of a user. The aim of the laboratory is to supply reliable, relevant and timely analytical information on biological samples. In health-related matters, in accordance with the objective of the laboratory, their importance is vital, as is the assurance that all the tools are in place for the fulfillment of its purpose. A good laboratory cycle, which includes the pre-analytical, analytical and post-analytical phases, is crucial in fulfilling the laboratory’s mission rapidly and efficiently. The present work - "Error in the pre-analytical phase: non-compliant samples versus procedures”, as part of the Master’s in Quality and Organization in the Clinical Analyses Laboratory, wishes to emphasize the importance of the pre-analytical phase, as the phase containing most errors which eventually lead to delays in the issue of results, or the one which enables those results not to be as reliable as desired, which can lead to false diagnosis and wrong clinical decisions. This phase, which starts with the medical request and ends with the arrival of the biological samples to the laboratory, entails a variety of procedures, which require the intervention of different players, not to mention a great number of factors, which influence the sample and the results. These factors, capable of somehow altering the “truth” of the analytical results, must be identified and taken into consideration so that we may ensure that the results help to make precise diagnoses and a correct evaluation of the user’s condition. Those collections which, due to any type of differences, do not originate samples capable of fulfilling their purpose, and are therefore not compliant with the objective, constitute an important source of error in this pre-analytical phase. In the present study, we consulted data from non-compliant blood and urine samples, detected at the laboratory during the 1st quarter of 2012, to find out the type of faults that happen and their frequency. The clinical analysis technicians working at the laboratory were asked to fill out a questionnaire regarding their daily procedures, forming in this way the population for this second part of the project. Completed and returned anonymously, this questionnaire intended to investigate the procedures for collections and, hypothetically, confront them with the verified non-compliant samples. In the first semester of 2012, and out of a total of 25319 users, 146 collections had to be repeated due to non-compliance. The “uncollected sample” was the most frequent non-compliance (>50%) versus “incorrect identification” which had only one occurrence. There were also unregistered non-compliance issues such as “inadequate preparation” and “inappropriately packaged sample”. The technicians proved to be competent professionals, with knowledge of the tasks they have to perform and eager to carry them out efficiently. We will certainly not be able to eliminate error, but recognizing its presence, detecting it and evaluating its frequency will help to decrease its occurrence and improve quality in the pre-analytical phase, giving it the relevance it has within the laboratory process.

O impacto da fase pré-analítica nos resultados : de que modo a fase pré-analítica pode interferir nos resultados de um trabalho de investigação

RESUMO: O impacto da fase pré-analítica nos resultados é o objectivo do nosso trabalho. Considera-se que esta fase é a mais importante no procedimento do teste no laboratório e que as variáveis independentes do laboratório são difíceis de controlar porque existem várias condicionantes quer dos profissionais, quer do doente, que por vezes não possibilita atribuir a importância desejada para que os resultados sejam fiáveis. De que modo a fase pré-analítica pode interferir nos resultados de um trabalho de investigação. Para podermos avaliar este processo é necessário considerar outra condicionante, nomeadamente, o facto de o teste ser realizado em laboratórios específicos com a qualidade certificada mas que não intervêm na colheita, manuseamento, armazenamento e transporte da amostra, procedimentos importantes que traduzem uma boa gestão da amostra na fase pré-analítica, necessária para a fiabilidade dos resultados dos estudos de investigação clínica.------------------ABSTRACT: The impact of pre-analytical phase in the results is the objective of our work Knowing that, this is the most important stage in the procedure of testing in the laboratory and because the independent variables the laboratory are difficult to control because these are several limitations of both the professional and the patient, sometimes does not assign importance to that desired result are reliable. How the pre-analytical phase can interfere with the result of a research work, there is another constraint to consider the testing process to be performed in individual laboratory with certified quality, but not involved in harvesting, handing, storage and transport of the sample, important procedures that translate a good sample management in the preanalytical phase, necessary for the reliability of results of clinical research studies.

Evaluation of the impact of a therapeutic drug monitoring program in a Swiss University Hospital

Background and objective: Therapeutic Drug Monitoring (TDM) has been introduced early 1970 in our hospital (CHUV). It represents nowadays an important routine activity of the Division of Clinical Pharmacology and Toxicology (PCL), and its impact and utility for clinicians required assessment. This study thus evaluated the impact of TDM recommendations in terms of dosage regimen adaptation. Design: A prospective observational study was conducted over 5 weeks. The primary objective was to evaluate the application of our TDM recommendations and to identify potential factors associated to variations in their implementation. The secondary objective was to identify pre-analytical problems linked to the collection and processing of blood samples. Setting: Four representative clinical units at CHUV. Main outcome measure: Clinical data, drug related data (intake, collection and processing) and all information regarding the implementation of clinical recommendations were collected and analyzed by descriptive statistics. Results: A total of 241 blood measurement requests were collected, among which 105 triggered a recommendation. 37% of the recommendations delivered were applied, 25 % partially applied and 34% not applied. In 4% it was not applicable. The factors determinant for implementation were the clinical unit and the mode of transmission of the recommendation (written vs oral). No clear difference between types of drugs could be detected. Pre-analytical problems were not uncommon, mostly related to completion of request forms and delays in blood sampling (equilibration or steady-state not reached). We have identified 6% of inappropriate and unusable drug level measurements that could cause a substantial cost for the hospital. Conclusion: This survey highlighted a better implementation of TDM recommendations in clinical units where this routine is well integrated and understood by the medical staff. Our results emphasize the importance of communication with the nurse or the physician in charge, either to transmit clinical recommendations or to establish consensual therapeutic targets in specific conditions. Development of strong partnerships between clinical pharmacists or pharmacologists and clinical units would be beneficial to improve the impact of this clinical activity.

Time and temperature dependant changes in red blood cell analytes used for testing recombinant erythropoietin abuse in sports.

There has been a long debate since the introduction of blood analysis prior to major sports events, to find out whether blood samples should be analysed right away on the site of competition or whether they should be transported and analysed in an anti-doping laboratory. Therefore, it was necessary to measure blood samples and compare the results obtained right after the blood withdrawal with those obtained after a few hours delay. Furthermore, it was interesting to determine the effect of temperature on the possible deterioration of red blood cell analytes used for testing recombinant erythropoietin abuse. Healthy volunteers were asked to give two blood samples and one of these was kept at room temperature whereas the second one was put into a refrigerator. On a regular basis, the samples were rolled for homogenisation and temperature stabilisation and were analysed with the same haematological apparatus. The results confirmed that blood controls prior to competition should be performed as soon as possible with standardised pre-analytical conditions to avoid too many variations notably on the haematocrit and the reticulocyte count. These recommendations should ideally also be applied to the all the blood controls compulsory for the medical follow up, otherwise unexplainable values could be misinterpreted and could for instance lead to a period of incapacity.