Volume 50, Issue 4

This review examines human chorionic gonadotropin (hCG) or pregnancy tests from multiple perspectives. It first investigates the molecule hCG and shows that the term represents five independent molecules differing in carbohydrate and meric structure that share a common amino acid sequence. The review goes on to show that multiple degradation produces also the need to be tested for an hCG or pregnancy test to be optimally efficient. The review then carefully examines the literature showing the sensitivity and specificity of automated laboratory tests. Point-of-care pregnancy tests are then investigated along with over-the-counter pregnancy tests. Appropriate detection of hyperglycosylated hCG, nicked hCG, nicked hCG missing the β-subunit C-terminal peptide and nicked hyperglycosylated hCG is a limitation on all pregnancy tests. In the opinion of the author, just one automated laboratory test, the Siemen’s Immulite, one point-of-care test, the Beckman-Coulter Icon 25, and one brand of over-the-counter device, First Response, are suitable for early pregnancy detection and possibly other applications.

Studies on platelet function have accelerated and gained popularity since the advent of novel treatment modalities and techniques on atherosclerotic vascular disease, such as antiplatelet drugs and stents. Today it is widely known that platelets exert a fundamental role in inflammation in addition to their long known role in homeostasis and thrombotic events. Interaction with endothelial cells and leukocytes mediates inflammation, contributes to atherogenesis and modulates immune activity. Platelet activation which is a central factor in many arterial disorders may be triggered by multiple pathways. Platelet activation is shown as forming a larger shape, aggregation and releasing various active contents. Mean platelet volume is a marker of platelet size, function and activation. Increased mean platelet volume is shown by active and large platelets that release more thromboxane A2 than smaller ones. The aim of this review is to determine whether early detection of platelet activation via increased mean platelet volume would help to recognize the pro-inflammatory state and administer appropriate and effective treatment properly. An easily detectable marker by using a prompt and functional technique would help our approach to inflammation caused by platelets.

The red blood cell (RBC) distribution width (RDW) is a measurement of the size variation as well as an index of the heterogeneity of the erythrocytes (i.e., anysocytosis), which is typically used in combination with the mean corpuscular volume to troubleshoot the cause of an underlying anemia. Reliable data emerged from a variety of clinical studies have, however, disclosed a new and unpredictable scenario in the clinical usefulness of this measure, supporting the hypothesis that RDW might be a useful parameter for gathering meaningful clinical information, either diagnostic or prognostic, on a variety of cardiovascular and thrombotic disorders. Highly significant associations have been described between RDW value and all-cause, non-cardiac and cardiac mortality in patients with coronary artery disease, acute and chronic heart failure, peripheral artery disease, stroke, pulmonary embolism and pulmonary arterial hypertension. It is however still unclear whether anysocytosis might be the cause, or a simple epiphenomenon of an underlying disease, such as inflammation, impaired renal function, undernutrition, oxidative damage, or perhaps an element of both. Nevertheless, RDW is an easy, inexpensive, routinely reported test, whose assessment might allow the acquisition of significant diagnostic and prognostic information in patients with cardiovascular and thrombotic disorders.

Background: The non-invasive, flexible and easy sample collection makes saliva an interesting source of DNA for research and diagnostic purposes. The aim of our study was to find the most suitable collection method for biological material from the oral cavity and the most effective DNA isolation technique for further analytic applications. Methods: DNA was isolated from swabs, Salivette saliva, whole saliva and samples collected with a commercial set for scraping of buccal cells. Phenol-chloroform extraction and isolation using a silica membrane based commercial kit were compared. Quantity of bacterial and human genomic DNA was estimated using real time PCR. The effects of storage conditions on DNA recovery were assessed. Results: Sample collection techniques significantly affected the quantity of DNA for both, silica membrane based and phenol-chloroform isolations. Whole saliva provided the largest number of bacterial and human genome copies after both extraction methods. Storage for 36 months at –20°C reduced recovery of human genomic DNA five times after silica membrane based extraction and 10 times after phenol-chloroform isolation. Conclusions: Whole saliva was found to be the most suitable material for human and bacterial DNA isolation. Both compared methods are useful considering the quantity of extracted DNA.

Background: The aim of this study was to establish a sensitive method that can detect the presence of not only the common but also the unusual or unknown α-globin gene deletions for screening of α-thalassemia. We used quantitative multiplex PCR of short fluorescent fragments (QMPSF) for the α-globin genes ( HBA ) to screen α-thalassemia deletions. Methods: We set up and validated HBA-QMPSF using 50 negative and 100 positive controls of deletional α-thalassemia. To evaluate its ability to detect the presence of the common and unusual or unknown α-globin gene deletions, 579 unrelated samples were simultaneously analyzed using this assay and multiplex Gap polymerase chain reaction (Gap-PCR). The inconsistent results were further confirmed by multiplex ligation-dependent probe amplification (MLPA). Results: HBA-QMPSF was capable of detecting α-globin gene deletions with an acceptable variability as shown by mean values (SD) of allele dosage for the heterozygous deleted control obtained from intra- and inter-experimental replicates [0.63 (0.01) and 0.61 (0.03)]. In 572 out of the 579 unrelated subjects, HBA-QMPSF and multiplex Gap-PCR gave consistent results. In seven cases which were finally proved to be composed of one rare deletion -- Thai /-α 3.7 , one novel deletion -- SEA /-α 2.8 , four ααα anti3.7 /αα and one ααα anti4.2 /αα triplications, HBA-QMPSF showed deletion or duplication in the α-globin gene while multiplex Gap-PCR failed to give the correct diagnosis. Conclusions: HBA-QMPSF is able to detect the presence of the common and unusual or unknown α-thalassemia deletions and duplications. It can be used as an initial screening test for α-thalassemia caused by HBA gene copy number alteration.

Background: The establishment of the causal relationship between high-risk human papillomavirus (HR-HPV) infection and cervical cancer and its precursors has resulted in the development of HPV DNA detection systems. Currently, real-time PCR assays for the detection of HPV, such as the RealTime High Risk (HR) HPV assay (Abbott) and the cobas® 4800 HPV Test (Roche Molecular Diagnostics) are commercially available. However, none of them enables the detection and typing of all HR-HPV types in a clinical high-throughput setting. This paper describes the laboratory workflow and the validation of a type-specific real-time quantitative PCR (qPCR) assay for high-throughput HPV detection, genotyping and quantification. This assay is routinely applied in a liquid-based cytology screening setting (700 samples in 24 h) and was used in many epidemiological and clinical studies. Methods: The TaqMan-based qPCR assay enables the detection of 17 HPV genotypes and β-globin in seven multiplex reactions. These HPV types include all 12 high-risk types (HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59), three probably high-risk types (HPV53, 66 and 68), one low-risk type (HPV6) and one undetermined risk type (HPV67). Results: An analytical sensitivity of ≤100 copies was obtained for all the HPV types. The analytical specificity of each primer pair was 100% and an intra- and inter-run variability of <6.4% was observed. Conclusions: The type-specific real-time PCR approach enables detection of 17 HPV types, identification of the HPV type and determination of the viral load in a single sensitive assay suitable for high-throughput screening.

Background: Historically, quantitative clinical diagnostic assays (QCDAs) have not been accepted for use in pharmacokinetic or bioequivalence studies because they do not fully comply with the US Food and Drug Administration (FDA) Guidance for Industry: Bioanalytical Method Validation (e.g., full calibration curve not generated with each analytical run). Samples from a bioequivalence study were analysed for insulin and C-peptide concentrations with QCDAs and guidance-conforming radioimmunoassays (RIAs) and the results compared across and within assays. Methods: Serum samples (n=1913) from study MKC-TI-142 were analysed first using the Roche E170 electrochemiluminescence immunoassay (ECLIA) for insulin concentration and the Immulite 2000 chemiluminescence immunoassay (CLIA) for C-peptide, and then using the corresponding Millipore RIAs. Results: The insulin assays were highly correlated: r 2 =0.92 excluding samples requiring dilution and R 2 =0.88 including all samples. There was increasing negative bias of the ECLIA compared with the RIA with increasing insulin, especially with samples that required dilution for the RIA. The ECLIA had significantly fewer below-quantifiable-limit samples, a larger dynamic analysis range without dilution, and tighter agreement within incurred sample reanalysis (ISR) as compared with the RIA. The C-peptide assays showed good agreement but the CLIA method produced ISR results that were in closer agreement with the original values. Conclusions: The science indicates that the QCDAs are appropriate for the quantification of serum insulin (ECLIA) and C-peptide (CLIA) concentrations in human pharmacokinetic and bioequivalence studies even though the calibration curve is not generated in each analytical run.

Background: Early detection of renal dysfunction is important in burn patients. This study evaluated whether serum cystatin C (CysC) is a potentially accurate and sensitive marker for identification of reduced glomerular filtration rate (GFR) and the risk factors of impaired renal function in major burn patients. Methods: A total of 48 adult patients with major burn injury were enrolled. Renal function was assessed using serum creatinine (sCr), 24-h urinary creatinine clearance (24-hCrCl), sCr-based formulae and CysC-based formulae on the second day and seventh day post-burn. Results: There was a high prevalence (27.1%) of acute impaired renal function in major burn patients in the first week post-burn. CysC-based formulae for estimated GFR (eGFR) are more accurate and sensitive for detection of impaired renal function than sCr-based formulae. Multivariate logistic regression analysis demonstrated that age (OR, 2.08; 95% CI 1.26–4.77) and the percentage of burn area (OR, 3.41; 95% CI 1.64–6.95) were independent risk factors of impaired renal function. Conclusions: The results of this study suggest that CysC is a more accurate and sensitive marker for identification of acute impaired renal function in major burn patients than sCr. It is important to measure CysC and calculate eGFR to prevent acute renal failure and modify drug doses in burn patients, especially those of older age and with major burn areas.

Background: In analogy with other areas of laboratory diagnostics, the pre-analytical phase is the leading source of variability also in urinalysis. We carried out a multicentric study for comparing results obtained from first-voided and mid-stream urine samples. Methods: Each of the six hospital-based clinical laboratories participating to this study recruited 50 healthy subjects among laboratory staff and/or their relatives. Two consecutive samples of the first morning micturition were collected by vacuum system, the first from the first-void and the second from the mid-stream. Routine urinalysis was performed using dip-stick automated analyzers for chemical examination and automated analyzers for formed particle examination (Sysmex UF-100, Sysmex UF-1000i and Iris iQ-200). Results: Counts of epithelial cells (EC), erythrocytes (ERY) and leukocytes (LEU) but not for cylinders (CAS) were significantly higher in the first-voided samples. A significantly higher count of EC, ERY and LEU was also observed between females and males in first-voided samples, whereas no significant difference could be found in mid-stream samples. Health related analyzer specific upper reference limits (URL) were CAS≤1, EC≤5, ERY≤19, Leu≤13 for UF-100; CAS≤1, EC≤4, ERY≤15, Leu≤11 for UF-1000i; CAS≤1, EC≤4, ERY≤18, Leu≤10 for iQ200. The overall prevalence of subjects with cellular elements count exceeding URL was also higher in first-voided than in mid-stream samples. Conclusions: Mid-stream urine was confirmed as the most appropriate sample, since the presence of contaminating elements, such as bacteria, analytes and formed particles are minimized.

Background: The percentage of hypochromic red cells (% Hypo-He) is now available on the Sysmex analyzer XE 5000 (Sysmex Corporation, Kobe, Japan). In this study the reliability of % Hypo-He in the assessment of iron status in the presence of inflammation is investigated. Methods: Ninety healthy subjects, 91 patients with iron deficiency anemia (IDA) previous to therapy, 65 patients with chronic kidney disease (CKD), 57 patients with anemia of chronic diseases (ACD) and 28 patients with storage iron deficiency (ACD/IDA) receiving therapy were analyzed. Pearson’s correlation, Independent samples t-test, receiver operating characteristic (ROC) curve analysis and Cohen’s k index were applied. Results: % Hypo-He values inversely correlated with the blood hemoglobin (Hb) (r=–0.78) and Hb content (MHC, r=–0.75). In patients with IDA and ACD/IDA the values obtained for % Hypo-He showed no statistical difference (p=0.5037). ROC analysis results for % Hypo-He in the detection of iron deficiency defined by a serum transferrin receptor (sTfR) >21 nmol/L. The area under the curve is 0.929; cut-off 3.6%, sensitivity 91.5% and specificity 80.9%. Using the threshold 3.6% the k index obtained in comparison to sTfR was 0.64. Conclusions: % Hypo-He is a reliable parameter for the detection of iron deficiency in patients with anemia in the presence of inflammation.

Background: A new flow cytometric (FC) BCR-ABL immunobead assay has been developed recently. Here we present the laboratory evaluation of the commercially available kit. Methods: Mononuclear cells were isolated, lysed and processed according to the instructions of the manufacturer. Anti-BCR antibodies adsorbed to capture beads bind the BCR-ABL fusion proteins of the lysed cells, a phycoerythrin (PE)-conjugated anti-ABL antibody is the detector reagent and mean fluorescence intensity (MFI) signals were recorded by flow cytometry. Detection of t(9;22)(q34;q11) translocation was carried out with a quantitative PCR assay. Results: MFI results of 20 normal peripheral blood samples were 88±8 (mean±SD), CV 9%. K562 cells were used as positive control. Within-batch imprecision was excellent (3.7% in the normal and 10% in the pathological range). Cut-off was chosen at MFI 112, where both sensitivity and specificity were 100%. Altogether 17 chronic myeloid leukemia (CML) and 16 acute leukemia samples were analyzed. All PCR positive samples (n=14) were positive with the FC method and negative results were also concordant (n=15). Frozen cell lysates can be stored up to 4 weeks without significant decrease of MFI signal. Conclusions: The FC BCR-ABL assay is a fast, reproducible and reliable method that may be incorporated into standard flow cytometric protocols to help clinical decision-making.

Background : The Enhanced Liver Fibrosis (ELF) score combining serum hyaluronan, N-terminal peptide of type III procollagen and tissue inhibitor of metalloproteinase-1, was reported as relevant in predicting liver fibrosis in chronic liver disease and proposed as an alternative to liver biopsy. Methods : We evaluated the ELF score in a cohort of chronic hepatitis C (CHC) patients included in a multicenter prospective study (ANRS HC EP 23 Fibrostar) using commercial reagents, different from those developed by the manufacturer of the Siemens ELF™ test. Results : In 512 CHC, the ELF score, using ROC curves, showed good predictive performances for severe fibrosis [AUROC=0.82; 95% confidence interval (CI) 0.78–0.86]and for cirrhosis (AUROC=0.85; 95% CI 0.81–0.90), but slightly lower for significant fibrosis (AUROC=0.78; 95% CI 0.74–0.82). The Obuchowski measure (0.81) showed that the ELF score globally performed as a marker of liver fibrosis. The ELF score predicted significant fibrosis (cut-off=9.0) with a sensitivity of 0.86, a specificity of 0.62, a positive predictive value (PPV) of 0.80 and a negative predictive value (NPV) of 0.70. For extensive fibrosis (cut-off=9.33), sensitivity was 0.90, specificity was 0.63, PPV was 0.73 and NPV was 0.85. For cirrhosis (cut-off=9.35), sensitivity was 0.83, specificity was 0.75, PPV was 0.44 and NPV was 0.95. Conclusions : This study confirms the ELF score performance as an index to predict liver fibrosis or cirrhosis in CHC. The ELF test, using validated reagents, could be added to the health authorities approved non-invasive tests in assessing fibrosis as surrogate to liver biopsy. a The ANRS HC EP 23 Fibrostar Study Group Sponsor: French National Agency for Research on aids and viral hepatitis (ANRS), Paris. Scientific Committee: Coordinators: J.-P. Zarski, Grenoble; M. Vaubourdolle, Paris; Hepatologists: J.-P. Bronowicki, Lille; P. Calès, Angers; A. Mallat, Créteil; P. Mathurin, Lille; Pathologists: N. Sturm, Grenoble; E.S. Zafrani, Créteil; Biologists: B. Poggi, Lyon; J. Guéchot, Paris; Methodologists and administrators: J.L. Bosson; A. Paris; ANRS: L. Allain, Paris. Methodologists and administrators: A. Bechet, J.-L. Bosson, A. Paris, A. Plages, S. Royannais, Centre Hospitalier Universitaire de Grenoble Biologists: R.-C. Boisson, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon M.-C. Gelineau, B. Poggi, Hôtel Dieu, Hospices Civils de Lyon J.-C. Renversez, C. Trocmé, Centre Hospitalier Universitaire de Grenoble J. Guéchot, E. Lasnier, M. Vaubourdolle, Hôpital Saint-Antoine, AP-HP, Paris H. Voitot, Hôpital Beaujon, AP-HP, Paris A. Vassault, Hôpital Necker, AP-HP, Paris A. Rosenthal-Allieri, Centre Hospitalier Universitaire de Nice A. Lavoinne, F. Ziegler, Centre Hospitalier Universitaire de Rouen M. Bartoli, C. Dorche, C. Lebrun, Centre Hospitalier de Chambéry A. Myara, Growwupe Hospitalier Paris Saint-Joseph, Paris F. Guerber, A. Pottier, Laboratoire Elibio-Groupe Oriade, Vizille, La Mure Hepatologists: V. Leroy, J.-P. Zarski, Centre Hospitalier Universitaire de Grenoble A. Poujol-Robert, R. Poupon, Hôpital Saint-Antoine, AP-HP, Paris A. Abergel, Centre Hospitalier Universitaire de Clermont-Ferrand J.P. Bronowicki, H ô pital de Brabois, Centre Hospitalier Universitaire de Nancy S. Metivier, J.P. Vinel, Hôpital Purpan, Centre Hospitalier Universitaire de Toulouse V. De Ledinghen, Hôpital Haut Levêque, Centre Hospitalier Universitaire de Bordeaux O. Goria, Centre Hospitalier Universitaire de Rouen M. Maynard-Muet, C. Trepo, Hôtel Dieu, Hospices Civils de Lyon Ph. Mathurin, Centre Hospitalier Universitaire de Lille H. Danielou, D. Guyader, Hôpital Pontchaillou, Centre Hospitalier Universitaire de Rennes O. Rogeaux, Centre Hospitalier de Chambéry S. Pol, Ph. Sogni, Hôpital Cochin, AP-HP, Paris A. Tran, Hôpital De l’Archet, Centre Hospitalier Universitaire de Nice P. Calès, Centre Hospitalier Universitaire d’Angers T. Asselah, P. Marcellin, Hôpital Beaujon, AP-HP, Clichy M. Bourlière, V. Oulès, Hôpital Saint Joseph, Assistance Publique- Hôpitaux de Marseille D. Larrey, Centre Hospitalier Universitaire de Montpellier F. Habersetzer, Centre Hospitalier Universitaire de Strasbourg M. Beaugrand, Hôpital Jean Verdier, AP-HP, Bondy Pathologists: N. Sturm, Centre Hospitalier Universitaire de Grenoble E.-S. Zafrani, Hôpital Henri Mondor, AP-HP, Créteil

Background: The epithelial cell adhesion molecule (EpCAM) embedded in the plasma membrane of circulating epithelial tumor cells (CETC) is used for detection and enrichment of circulating tumor cells in peripheral blood and as a target for anti-epithelial antibodies elicited during immune response in anti-tumor immunization. Although an efficient immune response against EpCAM can be generated, the clinical application of such approaches has not been successful so far and the detection of circulating epithelial cells is highly variable. One reason for these discrepancies may be that not all circulating tumor cells are equally accessible for the specific antibody. A possible reason might be masking of EpCAM by glycoproteins or membrane lipoproteins preventing antibody binding. Methods: We have tested the application of detergents as demasking agents known to be successful in demasking red blood cell epitopes and determined how and in which way they affect integral membrane proteins and membrane lipids. Results: The results showed that the polysorbate Tween ® 20, a non-ionic detergent like organic solvent is able to demask EpCAM on CETC and makes it better accessible to its specific antibody retaining at the same time full cell viability. Conclusions: The data presented in this study suggest that EpCAM is present on part of circulating tumor cells in a masked form and that it is possible to demask EpCAM on CETC of breast cancer patients using Tween ® 20 treatment. But further studies are needed to elucidate the mechanism of demasking.

Background: The presence of thyroid peroxidase antibodies (TPOab) are reported to be associated with improved outcome among breast cancer patients. We evaluated the correlation between TPOab and diagnostic parameters among newly diagnosed breast cancer patients. Methods: Three hundred and fourteen newly diagnosed patients with breast cancer, diagnosed and treated in Bethesda Essen between January 2002 and June 2006, were included in this study; 258 (82.2%) without TPOab (≤100 IU/mL) and 56 (17.8%) with TPOab (>100 IU/mL). Blood analysis was performed to measure serum levels of carcinoembryonic antigen (CEA), cancer antigen 15-3 (CA-15-3), free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH) and TPOab by radioimmunoassay. Data regarding age, tumor size, grading, TNM classification, receptor status, lymph node, and distant metastases were collected and analyzed from patient reports. Statistics were performed using Pearson’s χ 2 -test and logistic regression analysis. Results: There were no incidences of distant metastasis among 56 patients with TPOab, whereas 17 (6.6%) of 258 cases without TPOab displayed distant metastases (p=0.04). Logistic regression showed an inverse association of TPOab with CA-15-3 and CEA levels (p<0.001, respectively). Both groups, with and without TPOab, revealed no significant differences with respect to age, tumor size, grading, TNM classification, fT3, fT4, and receptor status. TPOab positive patients had higher TSH levels (2.55±3.58), compared to TPOab negative cases (1.20±1.15) (p<0.001). Conclusions: TPOab occurrence is associated with significantly lower frequency of distant metastases in breast cancer. TPOab level inversely correlates with the conventional tumor markers CA-15-3 and CEA.

Background: Recent studies strongly suggest the use of oncofetal fibronectin (onfFN) mRNA in diagnostic follow-up and staging due to its very high specificity for thyroid cancers. Since the use of this marker has not been well established yet, particularly in the monitoring of minimal residual disease, we have tried to verify the diagnostic power of onfFN and its usefulness as a prognostic molecular marker. For this reason, we evaluated (by RT-PCR) the presence of onfFN mRNAs, not only in blood samples and thyroid tissues (both normal and neoplastic), but also in different biological fluids (such as K 3 -EDTA blood samples, saliva and urine) belonging to healthy individuals. Methods: Molecular investigations, such as RT-PCR protocol, and sequencing of onfFN cDNAs evaluation of the above-mentioned samples were performed. Results: The onfFN transcript was largely expressed in all benign and malignant thyroid tissues [differentiated thyroid carcinomas (DTCs)] tested as well as in a large number of biological fluids; in particular, 100% urine samples were positive for onfFN transcript as compared to the thyroglobulin (Tg) mRNA (75%), while saliva was always positive for onfFN and never for Tg. These findings indicate that onfFN cannot be considered a marker specific for thyroid cancer presence. Finally, Tg results were positive in a large part of the samples, but not always in concomitance with onfFN. Conclusions: We underline how the complexity of onfFN transcripts could affect the RT-PCR procedure. In addition, the presence of onfFN transcripts in several normal and cancer tissues, along with non-thyroid biological fluids or cells, does not allow the use of this marker for cancer monitoring.

Background: Tumor mesothelin overexpression is present in different malignancies, including the majority of patients with pancreatic or biliary cancers. The objective of this study was to evaluate the use of shed serum mesothelin and megakaryocyte potentiating factor (MPF) concentrations as biomarkers for these cancers. Methods: A total of 151 individuals, divided into five groups, were retrospectively analyzed: healthy donors (n=15), patients with benign non-pancreatic conditions (n=52), benign pancreatic conditions (n=33), biliary carcinoma (n=9), and pancreatic ductal adenocarcinoma (n=42). Mesothelin and MPF concentrations were measured in serum with the Mesomark™ and Human MPF ELISA, respectively. Results: Mesothelin and MPF concentrations did not significantly differ among the five individual participant groups (p=0.34, p=0.33, respectively), nor did any other combination and pair-wise comparison of the participant groups demonstrated a significant difference in biomarker concentrations. In patients with pancreatic cancer, mesothelin or MPF concentrations were not associated with tumor stage (p=0.87, p=0.48, respectively) or differentiation grade (p=0.73, p=0.52, respectively). Conclusions: Serum mesothelin and MPF concentrations, measured with standard available ELISAs, were not specific for benign or pancreatic disease. Both biomarkers were not elevated in patients with pancreatic or biliary cancers, and consequently do not appear to be useful biomarkers for these malignancies.

Background: Many papers evaluating high sensitivity troponin assays make the diagnosis of myocardial infarction based on conventional troponin assays in clinical use at the time of recruitment. Such analyses often do not show superiority of high sensitivity assays compared with contemporary assays meeting precision guidelines. Methods: Three hundred and twenty-two patients presenting to the emergency department between November 2006 and April 2007 for evaluation for acute coronary syndrome had serial (0 h and >6 h) bloods taken to compare troponin assays (Roche hsTnT, Abbott TnI, Roche TnT and Vitros TnI). The diagnosis of myocardial infarction was made using each troponin assay separately with which that same assay was analysed for diagnostic performance. Results: The rate of myocardial infarction would be 38.9% using serial hsTnT, 31.3% using serial Abbott TnI, 27.1% using serial TnT and 26.4% using serial Vitros TnI. The baseline sensitivities (0 h) are 89.9% (85.2–93.3) for hsTnT, 77.9% (71.0–87.5) for Abbott TnI, 73.0% (65.6–78.7) for TnT and 86.8% (74.6–94.4%) for Vitros TnI. The specificities (peak 0 h and >6 h samples) are 93.1% (91.2–93.1) for hsTnT, 88.3% (86.5–88.3) for Abbott TnI, 92.2% (90.5–92.2) for TnT and 90.6% (70.1–90.6) for Vitros TnI. Conclusions: hsTnT has superior sensitivity for myocardial infarction than even assays at or near guideline precision requirements (Abbott and Vitros TnI). The specificity of hsTnT assay is not as poor as previous analyses suggest.

Background: Precise risk stratification is important in patients with non-ST elevation acute coronary syndromes (NSTE-ACS) on determination for hospitalization and intensity of treatment. A meta-analysis was performed in studies of patients with NSTE-ACS to evaluate the predictive nature of elevated N-terminal pro-brain natriuretic peptide (NT-proBNP). Methods: Online searches were conducted using database to identify suitable studies. A summary of relative risks (RRs) for death and myocardial infarction (MI) was calculated using random-effects modeling. We also calculated the pooled sensitivity, specificity, positive predictive value, and negative predictive value. Results: Thirteen studies were included. Elevated NT-proBNP levels were significantly associated with mortality [RR 4.89; 95% confidence interval (CI) 3.85–6.22] and incidence of MI (RR 1.66; 95% CI 1.24–2.22). The sensitivity and specificity for MI was 69.1% (95% CI 66.6%–71.6%) and 43.6% (95% CI 42.9%–44.3%), respectively, along with the positive and negative predictive values for MI of 8.2% (95% CI 7.7%–8.7%) and 95.1% (95% CI 94.6%–95.5%), respectively. Conclusions: Meta-analysis suggests that elevated NT-proBNP levels were associated with an increased risk for MI or death in patients with NSTE-ACS. Normal levels of NT-proBNP are certainly more helpful when selecting NSTE-ACS patients with likelihood for favorable outcomes.

Background: In many studies, high-molecular-weight (HMW) adiponectin has been considered the active form of adiponectin. However, whether HMW adiponectin is a good surrogate marker for coronary artery disease still needs to be elucidated. Methods: We conducted a hospital-based cross-sectional study to examine the relationship between total, HMW or non-HMW adiponectin concentrations and coronary stenosis in 83 male patients and 138 male controls. Results: Patients with coronary stenosis had significantly lower total adiponectin concentrations compared with controls. Non-HMW adiponectin concentrations in cases were significantly lower than the controls. However, there were no significant differences between cases and controls in HMW adiponectin concentrations. From the receiver operating characteristic (ROC) analysis, the area under the curve (AUC) for total and non-HMW adiponectin was significantly larger than that for HMW adiponectin concentrations. Of the three models, that for non-HMW adiponectin showed the largest AUC (total adiponectin 0.74, HMW adiponectin 0.54, and non-HMW adiponectin 0.79). Conclusions: Despite associations between total adiponectin levels and coronary stenosis, our data go against any apparent association between HMW adiponectin concentrations and coronary stenosis.