Clinical Chemistry and Laboratory Medicine (CCLM)

Published by De Gruyter

Volume 41 Issue 2

Issue of Clinical Chemistry and Laboratory Medicine (CCLM)

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Contents
Journal Overview

June 1, 2005

Erythrocyte Sedimentation Rate: Innovative Techniques for an Obsolete Test?

Mario Plebani

Page range: 115-116

June 1, 2005

Liquid Chromatography-Tandem Mass Spectrometry – Application in the Clinical Laboratory

Michael Vogeser

Page range: 117-126

Abstract

This review provides a concise survey of liquid chromatography-tandem mass spectrometry (LC-TMS) as an emerging technology in clinical chemistry. The combination of two mass spectrometers with an interposed collision cell characterizes LC-TMS as an analytical technology on its own and not just as a more specific detector for HPLC compared with conventional techniques. In LC-TMS, liquid chromatography is rather used for sample preparation but not for complete resolution of compounds of interest. The instrument technology of LC-TMS is complex and comparatively expensive; however, in routine use, methods are far more rugged compared to conventional chromatographic techniques and enable high-throughput analyses with very limited manual handling steps. Moreover, compared to both gas chromatography-mass spectrometry (GC-MS) and conventional HPLC techniques, LC-TMS is substantially more versatile with respect to the spectrum of analyzable compounds. For these reasons it is likely that LC-TMS will gain far more widespread use in the clinical laboratory than HPLC and GC-MS ever did. In this article, the key features of LC-TMS are described, method development is explained, typical fields of application are discussed, and personal experiences are related.

June 1, 2005

New Sensitive Method for the Measurement of Lysozyme and Lactoferrin for the Assessment of Innate Mucosal Immunity. Part I: Time-Resolved Immunofluorometric Assay in Serum and Mucosal Secretions

Emmanuel Bard, Sophy Laibe, Dominique Bettinger, Didier Riethmuller, Sabeha Biichlé, Estelle Seilles, Dominique Meillet

Page range: 127-133

Abstract

Mucous peristalsis, mucus and immunity proteins, such as lysozyme and lactoferrin, are part of humoral innate immunity. The aim of this study was to develop a quantitative method, a time-resolved-immunofluorometric assay, to measure lysozyme and lactoferrin in sera, saliva, stools and cervico-vaginal secretions. This method was validated in 51 healthy subjects. Linearity for lysozyme was between 1.02 and 25 μg/l and for lactoferrin between 1.02 and 100 μg/. The detection limit was 0.5 μg/l for lysozyme and 1 μg/l for lactoferrin. Albumin and α 1 -antitrypsin were measured by immuno-nephelometry to calculate salivary, intestinal and cervico-vaginal coefficients of excretion. Lysozyme and lactoferrin were present in all types of mucosal surfaces. Very high concentrations of lysozyme and lactoferrin were found in cervico-vaginal fluid (166.2 and 72.7 mg/l, respectively), compared to the concentrations found in the other mucosal fluids. Lysozyme in stools was produced at the rate of 0.42 mg/d compared to 0.02 mg/d lactoferrin production. Lysozyme and lactoferrin greatly exceeded the values expected from the molecular weight-affected seepage from plasma, suggesting primarily local synthesis in healthy subjects. Quantitative measurement of lysozyme and lactoferrin can aid in the assessment of the activity of mucus-associated lymphoid tissues in innate immunity, and can help in further understanding of the role of these proteins in mucosal diseases.

June 1, 2005

New Sensitive Method for the Measurement of Lysozyme and Lactoferrin to Explore Mucosal Innate Immunity. Part II: Time-Resolved Immunofluorometric Assay Used in HIV Patients with Oral Candidiasis

Sophy Laibe, Emmanuel Bard, Sabéha Biichlé, Julien Vielle, Laurence Millon, Christine Drobacheff, Estelle Seilles, Dominique Meillet

Page range: 134-138

Abstract

The aim of this study was to explore lysozyme and lactoferrin concentrations in human immunodeficiency virus (HIV)-infected patients with oropharyngeal candidiasis (OPC). These proteins were measured by time-resolved immunofluorometric assay, validated in Part I of this study, in paired serum and salivary secretions of 30 patients. Eleven HIV-positive patients without OPC, eight HIV-positive patients with OPC and eleven HIV-negative healthy subjects were included in the study. The relative coefficient of excretion of salivary albumin was used to establish protein origin. In serum, the low lactoferrin concentrations in HIV-infected patients with and without OPC (0.610 mg/l (p < 0.05) and 0.896 mg/l (p < 0.01) vs. 1.439 mg/l in healthy subjects) were probably due to a decrease in nonspecific immunity, particularly the polymorphonuclear cells. In HIV-infected patients with OPC, the high salivary lysozyme and lactoferrin concentrations (170.94 mg/l and 66.48 mg/l vs. 23.35 mg/l and 10.20 mg/l in healthy subjects, respectively) and their mean relative coefficient of excretion of above 1 indicated a high local production of lysozyme and lactoferrin in saliva. The development of OPC in HIV-infected patients could be a consequence of inefficient lysozyme and lactoferrin concentrations and of decreased cooperation between innate and adaptative immune systems.

June 1, 2005

Detection of Multiple Cytokines by Protein Arrays from Cell Lysate and Tissue Lysate

Ying Lin, Ruochun Huang, Xuan Cao, Shen-Ming Wang, Qing Shi, Ruo-Pan Huang

Page range: 139-145

Abstract

Previously we demonstrated that multiple cytokines could be simultaneously detected using an antibody-based protein array system with high sensitivity and specificity from conditioned medium and serum. Here, we created a higher density array system to simultaneously detect 35 cytokines from cell lysates and tissue lysates. This assay combines the advantages of the specificity of enzyme-linked immunosorbent assays (ELISA), sensitivity of enhanced chemiluminescence (ECL), and high-throughput of microspot. In this system, capture antibodies dissolved in methanol were spotted onto polyvinylidene difluoride (PVDF) membranes. The membranes were then incubated with tissue lysates or cell lysates. After removing unbound proteins by extensive washing, the membranes were exposed to horseradish peroxidase (HRP)-conjugated antibody(ies). The signals were visualized with an ECL system. High specificity, sensitivity, and accuracy of this approach were demonstrated. This approach can be used in any general laboratory setting without any sophisticated equipment. It should be feasible to extend this concept to develop a high-throughput protein array system. Combining nitrocellulose membrane-based and PVDF membrane-based approaches, the human cytokine array system can be applied to detect multiple cytokine expression from cell lysate, tissue lysate, serum, plasma, and conditioned medium. Future applications of this new approach include direct protein expression profiling, immunological disease diagnostics, and discovery of new biomarkers.

June 1, 2005

Free Serum Cortisol during the Postoperative Acute Phase Response Determined by Equilibrium Dialysis Liquid Chromatography-Tandem Mass Spectrometry

Michael Vogeser, Jan Groetzner, Christina Küpper, Josef Briegel

Page range: 146-151

Abstract

In severely ill patients low concentrations of the corticosteroid binding globulin are typically found; the aim of this study was to quantify directly free bioactive cortisol concentrations in the sera of postoperative cardiosurgical patients. Serum samples of 12 consecutive patients undergoing aortocoronary bypass surgery taken preoperatively and on the postoperative days 1 to 4 were analyzed. Total serum cortisol was quantified using liquid chromatography-tandem mass spectrometry with an on-line sample extraction system and tri-deuterated cortisol as the internal standard, and free serum cortisol was measured after over-night equilibrium dialysis. Whereas on the first postoperative day, the median total serum cortisol concentration was approximately two-fold increased compared to preoperative samples (preoperatively, 245 nmol/l (interquartile range (IQR) 203–293 nmol/l); first postoperative day, 512 nmol/l (IQR 410–611 nmol/l)), median dialyzable free cortisol concentration was almost seven-fold increased (preoperatively, 14.2 nmol/l (IQR 10.9–20.7 nmol/l); first postoperative day, 98.3 nmol/l (IQR 81.3–134 nmol/l)). On the fourth postoperative day, median free cortisol was still significantly increased compared to baseline sampling (p < 0.05), whereas median total cortisol was not. A median of 5.7% (IQR 5.4–7.0%) of total cortisol was found as free cortisol on the preoperative day, 21.2% (IQR 18.9–23.5%) on the first postoperative day and 10.5% (IQR 9.8–14.0%) on the fourth postoperative day. It is concluded that during the postoperative period the freeto-bound ratio of cortisol is highly variable and that during the acute phase response direct quantification of free bioactive cortisol concentrations seems to be biologically more appropriate than the measurement of total cortisol concentrations.

June 1, 2005

Analysis of the Dynamics of Cryoaggregation by Light-Scattering Spectrometry

Enrico Di Stasio, Patrizia Bizzarri, Maurizio Bove, Milvia Casato, Bruno Giardina, Massimo Fiorilli, Antonio Galtieri, Leopoldo P. Pucillo

Page range: 152-158

Abstract

Cryoglobulins are proteins that precipitate at temperatures below 37 °C. Cold-induced precipitation of proteins may occur in vivo secondary to several important diseases, and lead to pathological manifestations involving different organs. Cryoprecipitation may be observed in vitro by exposing serum samples, supposed to contain cryoglobulins, to low temperatures, but this needs several days to occur. Protein-protein interactions leading to cryoprecipitation are still poorly understood and the knowledge of the underlying mechanism may be relevant to the understanding of the onset of pathological manifestations. Using light-scattering spectrometry, we studied cryoprecipitation occurring in vitro at different temperatures and cryoglobulin concentrations. We describe the kinetics of the cold-induced precipitation of mixed cryoglobulins, measured as increase in turbidity. The plots obtained demonstrate that the cryoprecipitation did not occur as a single-step reaction, but consisted of four distinct phases where both temperature and cryoglobulin concentration affected the immune complexes formation. Light scatter spectrometry may provide a simple, sensitive and rapid method for the detection of cryoglobulins.

June 1, 2005

Biliary Bacteria in Living Related Liver Transplant Recipients: Microbiology and Rapid Detection System Using Flow Cytometry

Takashi Saito, Kazuyoshi Senda, Shunji Takakura, Naoko Fujihara, Toyoichiro Kudo, Yoshitsugu Iinuma, Tetsuya Kiuchi, Mitsune Tanimoto, Satoshi Ichiyama

Page range: 159-163

Abstract

Since cholangitis is a major complication in living related liver transplant (LRLT) recipients, rapid detection of biliary bacteria is necessary for the management of patients. We have developed a screening method for the detection of biliary bacteria using flow cytometry (FCM). Two hundred and seventy eight bile samples were obtained from 50 patients with biliary drainage tubes after LRLT at Kyoto University Hospital between July and September 2001. Of the 278 samples, 165 (59.3%) were culture-positive. The most common isolates were Enterococcus species, Pseudomonas species, Staphylococcus species, Klebsiella species, and Candida species. As the original FCM system was inadequate for specifically detecting bacteria in bile samples, we established the most appropriate gate and cut-off value from the particle distribution represented on scattergram of the forward-scattered light and fluorescent light intensity. The 3% cut-off value was most preferably related to the culture results. The FCM system detected biliary bacteria with a sensitivity of 93.9%, specificity of 81.4%, positive predictive value of 88.1%, negative predictive value of 90.2%, false-positive rate of 7.6%, false-negative rate of 3.6%, and percent agreement of 88.9% between FCM and culture. Therefore, FCM can be a useful method in clinical laboratories for the rapid screening for biliary bacteria in LRLT recipients.

June 1, 2005

Rapid Determination of Brain Natriuretic Peptide in Patients with Acute Myocardial Infarction

Mauro Panteghini, Claudio Cuccia, Graziella Bonetti, Franca Pagani, Raffaele Giubbini, Elena Bonini

Page range: 164-168

Abstract

We evaluated a rapid brain natriuretic peptide (BNP) assay (Triage ® BNP, Biosite Diagnostics) as indicator of infarct size, left ventricular (LV) dysfunction, and long-term survival in patients with acute myocardial infarction (AMI) during the coronary care unit stay. We studied 64 AMI patients in whom infarct size was estimated by creatine kinase isoenzyme MB (CK-MB) peak concentrations and single-photon emission computed tomography (SPECT) myocardial perfusion using technetium-99m sestamibi, and LV function by gated SPECT imaging. Measurements of BNP and SPECT were performed approximately 3 days after admission. SPECT was also repeated 3 months later. We found a significant correlation between BNP and both the peak CK-MB concentrations (r = 0.40, p = 0.001) and the perfusion defect size at SPECT (r = 0.38, p = 0.002). BNP was weakly related to LV ejection fraction (LVEF) assessed both early and 3 months after AMI (r = −0.29, p = 0.02; and r = −0.27, p = 0.04, respectively). The sensitivity and specificity of BNP for predicting survival of patients over 1 year of follow-up was 100% and 43%, respectively, with a negative predictive value of 100%. The positive predictive power of BNP was very modest (12%). Considering our results, the measurement of BNP did not look nearly as promising when tested in the setting of our cardiological intensive care.

June 1, 2005

Preparation and Characterization of Reference Materials for Human Pancreatic Lipase: BCR 693 (from Human Pancreatic Juice) and BCR 694 (Recombinant)

Jean-Marc Lessinger, Pantaleimon Arzoglou, Paul Ramos, Athanase Visvikis, Stella Parashou, Derek Calam, Christos Profilis, Georges Férard

Page range: 169-176

Abstract

There is a lack of certified reference material (CRM) for lipase catalytic activity. Consequently between-method comparability is very poor. The aim of this study was to produce two lipase CRMs, one from human pancreatic juice (BCR 693), and another using recombinant technologies (BCR 694). Lipase was purified from pancreatic juice, using column chromatography and isoelectric focusing. Recombinant lipase was produced with a transfected cell line and purified with column chromatography. Adding buffered bovine serum albumin and subsequent freeze-drying were used to stabilize both materials. A standardized titrimetric method was employed to compare their catalytic properties to those of two plasma pools of patients suffering from acute pancreatitis. About 5 kU (titrimetry, 37 °C) of each material were obtained. They were lyophilized without apparent modifications of their catalytic properties, which stayed identical to those exhibited by the enzyme present in patient's pools. Stability of both materials was estimated at several years when stored in a dry form at −20 °C. Both materials appear to have similar catalytic properties and stability and were found commutable as regards a reference method and a routine measurement procedure. An international certification campaign will be carried out to assign values to BCR 693 and BCR 694.

June 1, 2005

Commutability of the CRM 470 C-Reactive Protein Value in the Dade Behring N High Sensitivity CRP Assay

A. Myron Johnson, Thomas B. Ledue, Marilyn F. Collins

Page range: 177-182

Abstract

Certified Reference Material 470 (CRM 470) demonstrates commutability with both the manufacturer's calibrator and with dilutions of serum pools in the Dade Behring N High Sensitivity assay for C-reactive protein (CRP). Both regression and back calibration show similar nonlinearity for all materials, largely due to the method of calibration curve fitting used in this assay. Significant differences in values among the currently available commercial assays can be largely overcome by using appropriate calibration curve fitting and the recommended value transfer protocol, which includes a minimum of two assay runs on each of at least 3 separate days, with weight correction of all reconstitutions and dilutions. An initial weight-corrected dilution should be made each day because of the relatively high level of CRP in CRM 470. In our opinion, the degree of nonlinearity, imprecision, and differences in values in currently available assays renders the use of fixed clinical decision cut-points questionable for high-sensitivity CRP. An alternative approach is suggested.

June 1, 2005

Pilot External Quality Assessment Survey for Post-Market Vigilance of In Vitro Diagnostic Medical Devices and Investigation of Trueness of Participants' Results

Linda M. Thienpont, Dietmar Stöckl, Josef Kratochvíla, Bedrich Friedecký, Marek Budina

Page range: 183-186

Abstract

The Czech External Quality Assessment Scheme organized a survey using 14 fresh-frozen sera targeted for cholesterol and glucose by reference measurement procedures. The objective was to investigate whether it could fulfil a post-market vigilance function for in vitro diagnostic medical devices and assess trueness of participants' results. It revealed a mean bias of +5.1% for cholesterol and +3.7% for glucose (n ~150). However, the bias source (manufacturer or laboratory) could not be identified unequivocally because of the lack of homogeneous groups. This was due to the fact that laboratories mainly used reagents from manufacturers that do not market instruments or combined calibrators and reagents from different sources. Consequently, these habits did not allow the survey to fulfil the vigilance function. On the other hand, we were able to show the individual participants results for patient samples deviating from the true value (deviations >10% in ~20% of the laboratories). However, again, the survey failed in problem-solving via peergroup evaluation, even for participants that applied homogeneous tests. If other European schemes confirm this outcome, cooperation and/or participation of manufacturers may be the solution. The survey pointed out to the other participants, interchanging instrument, reagent and calibrator, that they are themselves responsible for the problems shown and hence also for problem-solving.

June 1, 2005

Fasting and Post-Glucose Load – Reference Limits for Peripheral Venous Plasma Glucose Concentration in Pregnant Women

Lone G.M. Jørgensen, Tine Schytte, Ivan Brandslund, Marta Stahl, Per Hyltoft Petersen, Bent Andersen

Page range: 187-199

Abstract

Recently both the American Diabetes Organization (ADA) and World Health Organization (WHO) have revised the diagnostic recommendations for gestational diabetes mellitus (GDM), however, they did not not reach agreement on the criteria for diagnosis, the referral criteria for the confirmatory oral glucose tolerance test (OGTT), its standardization, and diagnostic cut-off point. The aims of this study were to investigate if the fasting venous plasma glucose mmol/l (f-vPG) and the 2-hour venous plasma glucose mmol/l (2h-vPG) after a WHO standardized 75 g oral glucose tolerance test (OGTT) in a non-risk group of pregnant women during first and third trimester of pregnancy deviated from that of risk groups, to establish a reference interval for f-vPG and 2h-vPG, and to investigate the predictive role of f-vPG for the 2h-vPG glucose concentration. This is a population-based case-control study where a consecutive number of pregnant women were invited to screening irrespective of their risk factors for GDM. All women filled in a questionnaire of the Danish national screening program on risk factors and had f-vPG and the 2h-vPG measured. By ruling out women with GDM and risk factors, we isolated a non-risk reference class. The ln f-vPG parametric 97.5 centile was less than 5% higher during week 32 of pregnancy than during week 20, and therefore these groups were combined. The f-vPG 95% reference interval was from 4.01 mmol/l (95% CI: 3.96 to 4.07 mmol/l) to 5.26 mmol/l (95% CI: 5.19 to 5.34 mmol/l). “The true upper normal limit”, the 99.9 centile, was 5.69 mmol/l (95% CI: 5.59 to 5.80 mmol/l). The f-vPG was 0.6 mmol/l lower over the whole range in pregnant women compared to age-matched non-pregnant women. The distribution of 2h-vPG concentrations at week 20 was non-Gaussian and therefore considered non-homogeneous, while it was Gaussian distributed and homogeneous at week 32. The 2h-vPG 95% reference interval of the combined weeks was from 2.80 mmol/l (95% CI: 2.56 to 3.04 mmol/l) to 7.58 mmol/l (95% CI: 7.34 to 7.82 mmol/l), and the upper limit of normal (99.9 centile) was 8.96 mmol/l (95% CI: 8.63 to 9.29 mmol/l). Distributions of f-vPG and 2h-vPG were distinct in our defined risk classes. In individual cases, no systematic correlation was found between the f-vPG concentration at week 20 and week 32. The f-vPG concentrations at any of the weeks did not predict the 2h-vPG level and no single clinical risk factor was decisive for the presence of GDM.

June 1, 2005

Glutathione Peroxidase Activity and Serum Selenium Concentration in Intrinsic Asthmatic Patients

Durdi Qujeq, Behzad Hidari, Khezroolla Bijani, Hosein Shirdel

Page range: 200-202

Abstract

Serum glutathione peroxidase (GSH-Px) activity and selenium concentration were compared in intrinsic asthmatic patients and non-asthmatic control subjects. Serum GSH-Px activity and selenium concentration were assessed in 46 asthmatic patients and 75 age- and sex-matched non-asthmatic subjects by spectrophotometric assay. Mean serum GSH-Px activity was lower in intrinsic asthmatic subjects (9.4±2.6 μmol NADPH oxidized/min/g of protein) than in non-asthmatic subjects (16.3±2.9 μmol NADPH oxidized/min/g of protein). Mean serum selenium was lower in intrinsic asthmatic subjects (1.15±0.23 μM) than in non-asthmatic subjects (1.98±0.27 μM). Asthmatic patients have significantly lower concentration of selenium and GSH-Px activity measured in serum.

June 1, 2005

Increased Serum Soluble Transferrin Receptor Concentration Detects Subclinical Iron Deficiency in Healthy Adolescent Girls

Timo I. Takala, Pauli Suominen, Marjo Lehtonen-Veromaa, Timo Möttönen, Jorma Viikari, Allan Rajamäki, Kerttu Irjala

Page range: 203-208

Abstract

The objective of this study was to investigate whether the measurement of serum soluble transferrin receptor could detect subclinical iron deficiency in adolescent girls, and to assess the possible specificity-compromising effects of growth, menarche, and intensive physical activity. The study population consisted of 191 physically active (control) girls aged 9–15 years. Dietary iron intake was estimated at baseline, and after 6 and 12 months. Iron status of the subjects was assessed by haematological laboratory tests at 6 and 12 months. A 3-month iron and multivitamin supplementation was started after the visit at 6 months. The supplementation consistently decreased soluble transferrin receptor concentrations in subjects with initial values greater than 2.4 mg/l, which was determined by regression analysis to be the cut-off value for iron-deficient erythropoiesis. The 95% reference interval in the iron-replete subjects (0.9–2.4 mg/l) was consistent with this finding. In our population, the incidence of subclinical iron deficiency was 10%. Growth or physical activity had no effect on the iron status. This study shows that, similarly to adults, soluble transferrin receptor measurement can be used to detect subclinical iron deficiency in adolescents (competitive athletes or normal controls). We suggest that soluble transferrin receptor concentrations above 2.4 mg/l indicate clinically relevant iron deficiency in adolescents.

June 1, 2005

Serum Total Antioxidant Status, Erythrocyte Superoxide Dismutase and Whole-Blood Glutathione Peroxidase Activities in the Stanislas Cohort: Influencing Factors and Reference Intervals

Mohammed Habdous, Bernard Herbeth, Monique Vincent-Viry, John V. Lamont, Peters S. Fitzgerald, Sophie Visvikis, Gérard Siest

Page range: 209-215

Abstract

The aim of this work was to describe the factors influencing the levels of three antioxidant markers–total antioxidant status, erythrocyte copper/zinc superoxide dismutase (SOD), whole-blood selenium glutathione peroxidase–and to establish their reference intervals in supposedly healthy subjects. The studied population included 463 subjects, i.e. , 223 adults and 140 children aged 20 to 65 and 4 to 19 years, respectively. The effect of factors such as age, gender, body mass index, alcohol and tobacco consumption, menopause, drug intake, trace elements, transferrin, ferritin, albumin, bilirubin, haptoglobin, total proteins, uric acid, haemoglobin, and mean corpuscular volume of erythrocytes have been studied for the three antioxidant markers. Total antioxidant status (TAS) was higher in men than in women whatever the age (p < 0.001). Albumin and uric acid in men, women and girls, and total proteins in boys were significant determinants of TAS levels. Mean corpuscular volume of erythrocytes were negatively and significantly associated with SOD activity in men and in women (p < 0.01) but not in children. Among the studied determinants, none were found to influence the selenium glutathione peroxidase activity in the four groups. Reference intervals including the 90% confidence intervals were established by age and sex for the three antioxidant markers.

June 1, 2005

Plasma Thiols and Androgen Levels in Polycystic Ovary Syndrome

Jana Vrbíková, Jaroslava Tallová, Marie Bicíková, Katerina Dvoráková, Martin Hill, Luboslav Stárka

Page range: 216-221

Abstract

Homocysteine is a risk factor for ischemic heart disease; similarly as is hyperlipidemia or insulin resistance, which frequently occur in women with polycystic ovary syndrome. We examined the relationships between thiols and hormonal status or insulin resistance in 40 women (aged 25.8±7 years) with polycystic ovary syndrome and in 11 controls (33±5 years). Blood levels of homocysteine, glutathione, total and high density lipoprotein (HDL)-cholesterol, triglycerides, insulin, sex hormone-binding globulin, testosterone, androstenedione, dehydroepiandrosterone sulfate, and estradiol were determined. Student's t test and Spearman correlations were computed after adjustment for body mass index (BMI) and age. Homocysteine was significantly higher in polycystic ovary syndrome patients than in the control group (10.3±2.87 vs. 8.78±2.75 μmol/l; p < 0.05). In women with polycystic ovary syndrome, there were significant positive correlations between homocysteine and androstenedione (r = 0.329; p < 0.05) and glutathione and dehydroepiandrosterone sulfate (DHEA-S) (r = 0.469; p < 0.05). We conclude that homocysteine is increased in women with polycystic ovary syndrome and is probably linked to androgen levels but not to markers of insulin resistance or with lipid metabolism.

June 1, 2005

Pretreatment of Serum Containing Hemoglobin Vesicles (Oxygen Carriers) to Prevent Their Interference in Laboratory Tests

Hiromi Sakai, Kenichi Tomiyama, Yohei Masada, Shinji Takeoka, Hirohisa Horinouchi, Koichi Kobayashi, Eishun Tsuchida

Page range: 222-231

Abstract

Hemoglobin vesicles (HbV, diameter: 251±81 nm) are artificial oxygen (O 2 ) carriers encapsulating concentrated hemoglobin (Hb) solution with phospholipid bilayer membrane, and their O 2 transporting ability in vivo has been extensively studied. It is important to clarify the interference of the HbV suspension in clinical laboratory tests performed on serum and to establish a pretreatment method to avoid such an interference. The HbV suspension, acellular Hb solution ([Hb] = 10 g/dl) or saline, was mixed with a pooled human serum at various ratios up to 50 vol% ([Hb] = 5 g/dl), and the magnitude of the interference effect of HbV and Hb on 30 analytes was studied. The mixture of the HbV suspension and serum was ultracentrifuged (50000 g , 20 min) to remove the HbV particles as precipitate, and the supernatant was analyzed and compared with the saline control group. The HbV particles were also removed by centrifugation (2700 g , 30 min) in the presence of dextran (Mw 200 kDa). The HbV suspension showed considerable interference effects in most analytes. The majority of these effects was more serious than those of the acellular Hb solution. These findings are thought to be due to the light absorption of Hb in HbV and/or the light scattering generated in the suspension that interferes with the colorimetric and turbidimetric measurements. The components of HbV may also interfere with the chemical reactions of the studied assays. However, removal of the HbV from the supernatant diminished the interference in most of the assays: this is an advantage of HbV in comparison with acellular chemically modified Hb solutions.

June 1, 2005

Length of Sedimentation Reaction in Blood: a Comparison of the Test 1 ESR System with the ICSH Reference Method and the Sedisystem 15

Adolfo Romero, Manuel Muñoz, Gemma Ramírez

Page range: 232-237

Abstract

The aim of this study was to compare the performance of the automatic TEST 1 ESR system, SIRE Analytical Systems (TEST 1), with that of the the Sedisystem 15, Becton Dickinson (SEDI), and the International Council for Standardization in Haematology reference method (Westergren) for measuring the length of sedimentation reaction in blood (LSRB). This reaction was measured in 418 paired blood samples drawn in K 2 -EDTA vacuum tubes and specific tubes from patients scheduled for routine LSRB measurement. The TEST 1 system uses micro-sedimentation and quantitative capillary photometry technology, whereas the SEDI uses a CCD camera. For Westergren, a 200 mm column with 3.0 mm internal diameter was used. Compared to Westergren, TEST 1 gives accurate values of LSRB in most of the samples (mean of differences: 0.99±10.4 mm; 95% CI, −0.807 to 2.78 mm; n =131). Similar results were obtained in the comparison with SEDI (mean of differences: −0.626±8 mm; 95% CI, −1.756 to 0.5 mm; n =195). Compared to those of fresh blood samples, LSRB values were significantly lower in 24 h stored samples, either at 4 °C (21.5±2.3 vs. 19.4±2.2 mm; ρ (Spearman's coefficient of correlation): 0.981; n = 44) or at room temperature (19.1±2.5 vs. 16.2±2.1 mm; ρ: 0.903; n = 46). In conclusion, TEST 1 is a rapid, reliable system for automatic measurement of LSRB in standard K 2 -EDTA blood samples. It has a very low imprecision and maintains a good performance in 24 h stored samples. In addition, due to its operational characteristics (60 samples/20 min) it is a suitable tool for clinical laboratories with a high work load as well as for emergency laboratories.

June 1, 2005

The European Register for Specialists in Clinical Chemistry and Laboratory Medicine: Guide to the Register Version 2-2003 and Procedure for Re-registration

E. Gurr, U. Koller, V. Blaton, E. Lund, A. Harmoinen, S. Zerah, D. Rizos, D. Kenny, M. Pazzagli, M. Opp, H. Willems, H. Reguengo, J. Queraltó, H. Wallinder, J. McMurray, R. Jansen, M. Parviainen, G. Beastall, K. P. Kohse

Page range: 238-247

Abstract

The European Communities Confederation of Clinical Chemistry and Laboratory Medicine (EC4) opened a Register for European Chemists in 1997. The operation of the Register is undertaken by a Register Committee (EC4RC). During the last 5 years more than 1400 clinical chemists entered the register. In this article an update of the first Guide to the Register is given, based on the experience of 5 years of operation and the development of the discipline. The registration is valid for 5 years. In a second part the procedure and the conditions for re-registration are presented.

July 27, 2005

Journées Internationales de Biologie – JIB 2002: A Booming European Show!

Page range: 248-249

July 27, 2005

Meetings and Awards

Page range: 250-252

About this journal

Objective
Clinical Chemistry and Laboratory Medicine (CCLM) publishes articles on novel teaching and training methods applicable to laboratory medicine. It is focused on basic and applied research and cutting-edge clinical laboratory medicine. CCLM is one of the leading journals in the field, with an impact factor over 3.5. All contributions submitted for publication in CCLM are single-blind peer reviewed by at least two experts in the field. CCLM is led by a multi-institutional editorial board. It is issued monthly, both in print and electronically. Letters to the Editor and Congress Abstracts are published online only.

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Topics

clinical biochemistry
clinical genomics and molecular biology
clinical haematology and coagulation
clinical immunology and autoimmunity
clinical microbiology
drug monitoring and analysis
evaluation of diagnostic biomarkers
disease-oriented topics (cardiovascular disease, cancer diagnostics, diabetes)
new reagents, instrumentation and technologies
new methodologies
reference materials and methods
reference values and decision limits
quality and safety in laboratory medicine
translational laboratory medicine
clinical metrology

Article formats
Research Articles, Reviews, Mini Reviews and Opinion Papers on all aspects of clinical chemistry and laboratory medicine, Guidelines and Recommendations, Point/Counterpoint Articles, Letters to the Editor, Editorials

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