Volume 56, Issue 5

Epidermal growth factor receptor (EGFR) serves as a co-target for dual/pan-EGFR-inhibitors in breast cancer. Findings suggest that EGFR and EGFR-ligands are involved in resistance towards certain breast cancer treatments. The aim is to explore the validity of EGFR and EGFR-ligands in blood as prognostic and predictive biomarkers in breast cancer. The systematic review was conducted in accordance to the PRISMA guidelines. Literature searches were conducted to identify publications exploring correlations between EGFR/EGFR-ligands in serum/plasma of breast cancer patients and prognostic/predictive outcome measures. Sixteen publications were eligible for inclusion. Twelve studies evaluated EGFR, whereas five studies evaluated one or more of the EGFR-ligands. Current evidence indicates associations between low baseline serum-EGFR and shorter survival or reduced response to treatment in patients with advanced breast cancer, especially in patients with estrogen and/or progesterone receptor positive tumors. The prognostic and predictive value of EGFR and EGFR-ligands in blood has only been investigated in highly selected subsets of breast cancer patients and most studies were small. This is the first systematic review evaluating the utility of EGFR and EGFR-ligands as predictive and prognostic biomarkers in blood in breast cancer. Further exploration in large well-designed studies is needed.

The coding region of GSTP1 gene is preceded by a large CpG-rich region that is frequently affected by methylation. In many cancer types, GSTP1 is affected by hypermethylation and, as a consequence, it has a low expression. The aim of this review is to give an overview on GSTP1 methylation studies with a special focus on liquid biopsy, thus to summarize methods, results, sample types, different diseases, to have a complete information regarding this promising epigenetic biomarker. We used all the most valuable scientific search engines (PubMed, Medline, Scopus and Web of Science) searching the following keywords: GSTP1 , methylation, cancer, urine, serum, plasma and blood. GSTP1 is a largely investigated tissue biomarker in several malignancies such as prostate, breast, lung and hepatocellular carcinoma with good performances especially for diagnostic purposes. As a liquid biopsy biomarker, it has been mainly investigated in prostate cancer (PCa) where it showed a high specificity but a low sensitivity; thus, it is recommended in combination with other biomarkers. Despite the large number of published papers and the promising results, GSTP1 has not yet entered the clinical practice even for PCa diagnosis. For this reason, further large and prospective studies are needed to validate this assay.

We suggest here a pragmatic approach for managing results of clinical chemistry testing in hemolyzed samples collected from adults/older children, attempting to balance the need to produce quality laboratory data with clinical urgency of releasing test results. Automatic measurement of the hemolysis index (H-index) in serum or plasma is highly advisable, whilst low-quality assessment of this test remains less good than a visual inspection. Regarding its practical use, when the H-index value does not generate an analytically significant bias, results can be released, whilst when the value is associated with analyte variation in a range between analytically and clinically significant bias (i.e. variation does not exceed the reference change value [RCV]), results of hemolysis-sensitive tests can be released in association with a comment describing the direction in which data are potentially altered, suggesting the need to collect another sample. When the H-index is associated with analyte variation exceeding clinically significant bias (i.e. variation exceeds the RCV), results of hemolysis-sensitive tests should be suppressed and replaced with a comment that biased results cannot be released because the sample is preanalytically compromised and advising the recollection of another sample. If H-index values reach an even higher critical cut-off (i.e. H-index corresponding to a cell-free hemoglobin concentration ≥10 g/L), all laboratory data may be unreliable and should hence be suppressed and replaced with a comment that all data cannot be released because the sample is grossly hemolyzed, also suggesting the recollection of another sample. Due to inaccuracy and imprecision, the use of corrective formulas for adjusting data of hemolysis-sensitive tests is discouraged.

Background: To limit risks of miscarriages associated with invasive procedures of current prenatal diagnosis practice, we aim to develop a personalized medicine-based protocol for non-invasive prenatal diagnosis (NIPD) of monogenic disorders relying on the detection of paternally inherited mutations in maternal blood using droplet digital PCR (ddPCR). Methods: This study included four couples at risk of transmitting paternal neurofibromatosis type 1 ( NF1 ) mutations and four couples at risk of transmitting compound heterozygous CFTR mutations. NIPD was performed between 8 and 15 weeks of gestation, in parallel to conventional invasive diagnosis. We designed specific hydrolysis probes to detect the paternal mutation and to assess the presence of cell-free fetal DNA by ddPCR. Analytical performances of each assay were determined from paternal sample, an then fetal genotype was inferred from maternal plasma sample. Results: Presence or absence of the paternal mutant allele was correctly determined in all the studied plasma DNA samples. Conclusions: We report an NIPD protocol suitable for implementation in an experienced laboratory of molecular genetics. Our proof-of-principle results point out a high accuracy for early detection of paternal NF1 and CFTR mutations in cell-free DNA, and open new perspectives for extending the technology to NIPD of many other monogenic diseases.

Background: Acute kidney injury (AKI) in cirrhotic patients may be functional (hepatorenal syndrome [HRS]) or structural (acute tubular necrosis [ATN]). The differentiation between these two conditions remains challenging; no definite biomarker with a clear cutoff value had been declared. miRNAs seem to be attractive innovative biomarkers to identify the nature of kidney injury in cirrhotic patients. This study aimed to investigate the possibility of using miR-21, miR-210 and miR-146a as differentiating markers between HRS and ATN. Methods: This pilot case control study included 50 patients with liver cirrhosis; 25 with HRS and another 25 with ATN beside 30 healthy controls. Real-time qPCR was used to measure the circulating miRNA tested. Results: Higher levels of miR-21 were observed in both ATN and HRS vs. controls with statistically significant difference between ATN and HRS. The means were 9.466±3.21 in ATN, 2.670±1.387 in HRS and 1.090±0.586 in controls. miR-146a and miR-210 were both significantly lower in ATN and HRS compared to controls with statistically significant differences between ATN and HRS. The means of miR-210 were 1.020±0.643, 1.640±0.605 and 3.0±0.532 in ATN, HRS and controls, respectively. The means of miR-146a were 2.543±1.929, 4.98±1.353 and 6.553±0.426 in ATN, HRS and controls, respectively. ROC analyses proved that the three studied mi-RNAs can be used as differentiating biomarkers between ATN and HRS with the best performance observed with mi-21 achieving specificity and sensitivity equal 96%. Conclusions: miR-21, miR-210 and miR-146a may be candidate differentiating markers between HRS and ATN in cirrhotic patients.

Background: The ABO gene has been widely studied and associated with many different diseases such as myocardial infarction and diabetes. Pleiotropic effects of the ABO locus have been demonstrated. Indeed it affects different phenotypes such as E- and P-selectins, triglycerides and total cholesterol. The goal of this work was to study the SNP rs644234 located in the ABO gene with different phenotypes related with diseases where the ABO gene has been involved. Methods: We analyzed the SNP rs644234 located in the ABO gene, by performing association studies with different lipid phenotypes as well as with the soluble E-selectin levels in 348 adults from the STANISLAS Family Study. Results: The major rs644234*T allele was associated with increased levels of soluble E-selectin (p=8.7×10 −12 ). According to the lipid phenotypes, the major rs644234*T allele was associated with decreased levels of apolipoproteins E (ApoE) (p=0.001) and low-density lipoprotein cholesterol (LDL-C) (p=0.032) but was associated with increased levels of high-density lipoprotein cholesterol (HDL-C) (p=0.013). The association of the HDL-C was especially significant in the male individuals (p=0.001). Conclusions: We confirmed that ABO is a major locus for serum soluble E-selectin levels variability, and we also correlated this gene with different lipid phenotypes. Furthermore, we demonstrated that this pleiotropic effect is independent. This is the first time that a correlation has been made between the A BO gene and the ApoE levels. According to these results, the major allele of this polymorphism may have a protective effect when it comes to cardiovascular related diseases, and more specifically when it comes to the lipid phenotypes.

Background: Customer satisfaction is a key quality indicator of laboratory service. Patients and physicians are the ultimate customers in medical laboratory, and their opinions are essential components in developing a customer-oriented laboratory. Methods: A longitudinal investigation of customer satisfaction was conducted through questionnaires. We designed two different questionnaires and selected 1200 customers (600 outpatients and 600 physicians) to assess customer satisfaction every other year from 2012 to 2016. Items with scores <4 were considered unsatisfactory, and corrective actions should be taken. Results: The completion rates of physicians were 96.8% in 2012, 97% in 2014 and 96.5% in 2016, whereas the rates of patients were 95.3%, 96.2% and 95.2%, respectively. In 2012, the most dissatisfaction items were test turnaround time (3.77 points) and service attitude (3.87 points) from physicians, whereas waiting time (3.58 points) and examination environment (3.64 points) were the most dissatisfaction items from patients. After corrective actions were taken, the result of satisfaction in 2014 was better, which illustrated our strategy was effective. However, some items remained to be less than 4, so we repeated the survey after modifying questionnaires in 2016. However, the general satisfaction points of the physicians and patients reduced in 2016, which reminded us of some influential factors we had neglected. Conclusions: By using dynamic survey of satisfaction, we can continuously find deficiencies in our laboratory services and take suitable corrective actions, thereby improving our service quality.

Background: Therapeutic drug monitoring (TDM) of sirolimus is essential in transplant recipients. We evaluated the performance of a new electrochemiluminescence immunoassay (ECLIA) for measuring sirolimus concentrations in whole blood at five European laboratories. Methods: Study assessments included repeatability, intermediate precision and functional sensitivity (concentration at coefficient of variation [CV] of 20%) experiments. Method comparisons with liquid chromatography-tandem mass spectrometry (LC-MS/MS; reference method) and two immunoassays (chemiluminescent microparticle immunoassay [CMIA] and antibody-conjugated magnetic immunoassay [ACMIA]) were performed using native samples from patients with kidney transplants. Results: Imprecision testing CVs were ≤6.4% and ≤10.7% across the sirolimus concentration range for both repeatability and intermediate precision, respectively. The ECLIA showed excellent functional sensitivity: the CV did not reach 20%; the CV at the assay’s limit of quantitation (1.5 μg/L) was 7.0%. Agreement between the ECLIA and LC-MS/MS using native kidney samples was close, with weighted Deming regression analysis yielding a slope of 1.05, an intercept of 0.154 μg/L and a Pearson’s correlation coefficient (r) of 0.94, while Bland-Altman analysis showed a combined mean bias of 0.41 μg/L (±2 standard deviation [SD], −1.96 to 2.68). The ECLIA also showed good correlation with the two other immunoassays: the CMIA (slope=0.91, intercept=0.112 μg/L and r=0.89) and the ACMIA (slope=0.99, intercept=0.319 μg/L and r=0.97). Conclusions: The ECLIA showed good precision, functional sensitivity and agreement with other methods of sirolimus measurement used in clinical practice, suggesting that the assay is suitable for TDM in transplant recipients and provides an alternative to LC-MS/MS.

Background: The aim of our study was to perform verification of serum indices on three clinical chemistry platforms. Methods: This study was done on three analyzers: Abbott Architect c8000, Beckman Coulter AU5800 (BC) and Roche Cobas 6000 c501. The following analytical specifications were verified: precision (two patient samples), accuracy (sample with the highest concentration of interferent was serially diluted and measured values compared to theoretical values), comparability (120 patients samples) and cross reactivity (samples with increasing concentrations of interferent were divided in two aliquots and remaining interferents were added in each aliquot. Measurements were done before and after adding interferents). Results: Best results for precision were obtained for the H index (0.72%–2.08%). Accuracy for the H index was acceptable for Cobas and BC, while on Architect, deviations in the high concentration range were observed (y=0.02 [0.01–0.07]+1.07 [1.06–1.08]x). All three analyzers showed acceptable results in evaluating accuracy of L index and unacceptable results for I index. The H index was comparable between BC and both, Architect (Cohen’s κ [95% CI]=0.795 [0.692–0.898]) and Roche (Cohen’s κ [95% CI]=0.825 [0.729–0.922]), while Roche and Architect were not comparable. The I index was not comparable between all analyzer combinations, while the L index was only comparable between Abbott and BC. Cross reactivity analysis mostly showed that serum indices measurement is affected when a combination of interferences is present. Conclusions: There is heterogeneity between analyzers in the hemolysis, icteria, lipemia (HIL) quality performance. Verification of serum indices in routine work is necessary to establish analytical specifications.

Background: The aim of the current study was to evaluate the commutability of commercial control materials and human serum pools and to investigate the suitability of the materials for the external quality assessment (EQA) of serum apolipoprotein A-I (apo A-I) measurement. Methods: The Clinical and Laboratory Standards Institute (CLSI) EP14-A3 protocol was used for the commutability study. Apo A-I concentrations in two levels of commercial control materials used in EQA program, two fresh-frozen human serum pools (FSPs) and two frozen human serum pools prepared from residual clinical specimens (RSPs) were measured along with 50 individual samples using nine commercial assays. Measurement results of the 50 individual samples obtained with different assays were pairwise analyzed by Deming regression, and 95% prediction intervals (PIs) were calculated. The commutability of the processed materials was evaluated by comparing the measurement results of the materials with the limits of the PIs. Results: The FSP-1 was commutable for all the 36 assay pairs, and FSP-2 was commutable for 30 pairs; RSP-1 and RSP-2 showed commutability for 27/36 and 22/36 assay pairs, respectively, whereas the two EQA materials were commutable only for 4/36 and 5/36 assay pairs, respectively. Conclusions: Non-commutability of the tested EQA materials has been observed among current apo A-I assays. EQA programs need either to take into account the commutability-related biases in the interpretation of the EQA results or to use more commutable materials. Frozen human serum pools were commutable for most of the assays.

Background: Apolipoprotein E (APOE) is a key player in lipid transport and metabolism and exists in three common isoforms: APOE2, APOE3 and APOE4. The presence of the E4 allelic variant is recognized as a major genetic risk factor for dementia and other chronic (neuro)degenerative diseases. The availability of a validated assay for rapid and reliable APOE4 classification is therefore advantageous. Methods: Biochip array technology (BAT) was successfully applied to identify directly the APOE4 status from plasma within 3 h, through simultaneous immunoassay-based detection of both specific APOE4 and total APOE levels. Results: Samples (n=432) were first genotyped by polymerase chain reaction (PCR), and thereafter, using BAT, the corresponding plasma was identified as null, heterozygous or homozygous for the E4 allele by calculating the ratio of APOE4 to total APOE protein. Two centers based in Austria and Ireland correctly classified 170 and 262 samples, respectively, and achieved 100% sensitivity and specificity. Conclusions: This chemiluminescent biochip-based sandwich immunoarray provides a novel platform to detect rapidly and accurately an individual’s APOE4 status directly from plasma. The E4 genotype of individuals has been shown previously to affect presymptomatic risk, prognosis and treatment response for a variety of diseases, including Alzheimer’s disease. The biochip’s potential for being incorporated in quantitative protein biomarker arrays capable of analyzing disease stages makes it a superior alternative to PCR-based APOE genotyping and may deliver additional protein-specific information on a variety of diseases in the future.

Background: Variation in metabolism, toxicity and therapeutic efficacy of thiopurine drugs is largely influenced by genetic polymorphisms in the thiopurine S-methyltransferase ( TPMT ) gene. Determination of TPMT activity is routinely performed in patients to adjust drug therapy. Methods: We further optimized a previously established high-performance liquid chromatography (HPLC) method by measuring TPMT activity in whole blood instead of isolated erythrocytes, which is based on conversion of 6-mercaptopurine to 6-methylmercaptopurine using S-adenosyl-methionine as methyl donor. Results: The simplified TPMT whole-blood method showed similar or better analytical and diagnostic performance compared with the former erythrocyte assay. The whole-blood method was linear for TPMT activities between 0 and 40 nmol/(mL·h) with a quantification limit of 0.1 nmol/(mL·h). Within-day imprecision and between-day imprecision were ≤5.1% and ≤8.5%, respectively. The optimized method determining TPMT activity in whole blood (y) showed agreement with the former method determining TPMT activity in erythrocytes (x) (n=45, y=1.218+0.882x; p>0.05). Phenotype-genotype concordance (n=300) of the whole-blood method was better when TPMT activity was expressed per volume of whole blood (specificity 92.2%), whereas correction for hematocrit resulted in lower genotype concordance (specificity 86.9%). A new cutoff for the whole-blood method to distinguish normal from reduced TPMT activity was determined at ≤6.7 nmol/(mL·h). Conclusions: This optimized TPMT phenotyping assay from whole blood using 6-MP as substrate is suitable for research and routine clinical analysis.

Background: We sought to evaluate the role of soluble ST2 (suppression of tumorigenicity) serum concentrations in polytraumatized patients and its potential role as biomarker for pulmonary complications. Methods: We included severely injured patients (injury severity score≥16) admitted to our level I trauma center and analyzed serum samples obtained on the day of admission and on day 2. Furthermore, patients with isolated thoracic injury and healthy probands were included and served as control groups. Serum samples were analyzed for soluble ST2 concentrations with a commercially available ELISA kit. Results: A total of 130 patients were included in the present study. Five patients with isolated thoracic injury and eight healthy probands were further included. Serum analyses revealed significantly elevated concentrations of soluble ST2 in polytraumatized patients compared to patients suffering from isolated thoracic trauma and healthy probands. In polytraumatized patients who developed pulmonary complications (acute respiratory distress syndrome and pneumonia) and in patients who died, significantly higher serum concentrations of soluble ST2 were found on day 2 (p<0.001). Serum concentrations of soluble ST2 on day 2 were of prognostic value to predict pulmonary complications in polytraumatized patients (area under the curve=0.720, 95% confidence interval=0.623–0.816). Concomitant thoracic trauma had no further impact on serum concentrations of soluble ST2. Conclusions: Serum concentrations of soluble ST2 are upregulated following polytrauma. Increased concentrations were associated with worse outcome.

Background: Detection of acute myocardial infarction (AMI) is mainly based on a rise of cardiac troponin with at least one value above the 99th percentile upper reference limit (99th URL). However, circulating high-sensitive cardiac troponin T (hs-cTnT) concentrations depend on age, sex and renal function. Using an analytical imprecision-based approach, we aimed to determine age- and sex-specific hs-cTnT 99th URLs for patients without chronic kidney disease (CKD). Methods: A 3.8-year retrospective analysis of a hospital laboratory database allowed the selection of adult patients with concomitant plasma hs-cTnT (<300 ng/L) and creatinine concentrations, both assayed twice within 72 h with at least 3 h between measurements. Absence of AMI was assumed when the variation between serial hs-cTnT values was below the adjusted-analytical change limit calculated according to the inverse polynomial regression of analytical imprecision. Specific URLs were determined using Clinical and Laboratory Standards Institute (CLSI) methods, and partitioning was tested using the proportion method, after adjustment for unequal prevalences. Results: After outlier removal (men: 8.7%; women: 6.6%), 1414 men and 1082 women with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m 2 were assumed as non-AMI. Partitioning into age groups of 18–50, 51–70 and 71–98 years, the hs-cTnT 99th URLs adjusted on French prevalence were 18, 33, 66 and 16, 30, 84 ng/L for men and women, respectively. Age-partitioning was clearly required. However, sex-partitioning was not justified for subjects aged 18–50 and 51–70 years for whom a common hs-cTnT 99th URLs of about 17 and 31 ng/L could be used. Conclusions: Based on a laboratory approach, this study supports the need for age-specific hs-cTnT 99th URLs.

Background: The study endpoint was to analyze the effect of preanalytical (time, temperature, anticoagulant) and analytical (imprecision, correlation between volume and platelet concentration) variables on mean platelet volume (MPV). A further aim was to calculate in an adult population the reference intervals using the Sysmex XE-5000 analyzer. A critical evaluation was also made of the clinical utility of these parameters. Methods: Analyses of the above values were performed in duplicate in 170 healthy adults of both sexes: (1) within 30 min from collection, and (2) after 4 h. To evaluate stability over time, the value of the platelet parameters of 20 subjects were determined, a re-analysis being performed for a period of up to 24 h on samples maintained at room temperature and 4°C using either K 2 -EDTA or Na-citrate as anticoagulants. Results: The stability over time of MPV closely depends on the anticoagulant used, storage temperature and time interval between venipuncture and analysis. An inverse, non-linear correlation between MPV and platelet count was also found. Conclusions: In view of their effect on MPV and other related indices, the preanalytical and analytical variables make them, little more than experimental.

Background: Reference intervals (RIs) play key roles in clinical diagnosis, treatment and prognosis. However, RIs for clinical testing tend to be confined to the general population, and RIs for pregnant women are not very comprehensive. In this study, we establish RIs for prolactin (PRL) in healthy pregnant and postpartum women in the Chinese population. Methods: Healthy pregnant women (n=378) were divided into groups according to whether they were in the first, second or third trimester of pregnancy. Healthy postpartum women (n=493) were separated into four groups according to mode of delivery as follows: postvaginal (24 and 48 h) or postcesarean (24 and 48 h). Healthy, non-pregnant women (n=123) were enrolled as a control group. Serum PRL levels were measured by electrochemiluminescence immunoassay, and RIs were established for each group. Results: The RIs for PRL were as follows: healthy non-pregnant women, 178.89–757.52 μIU/mL; first trimester, 621.20–3584.00 μIU/mL; second trimester, 1432.00–5349.68 μIU/mL; third trimester, 4087.33–9733.65 μIU/mL; 24 and 48 h postvaginal delivery (combined), 7865.36–10998.86 μIU/mL; and 24 and 48 h postcesarean delivery, 4556.41–7675.99 and 6578.45–9980.45 μIU/mL, respectively. Conclusions: PRL RIs for pregnant women were established according to trimester, days postpartum and mode of delivery, thus providing a clinical reference for medical staff.

Background: Recently, the use of separate gender-partitioned patient medians of serum sodium has revealed potential for monitoring analytical stability within the optimum analytical performance specifications for laboratory medicine. The serum albumin concentration depends on whether a patient is sitting or recumbent during phlebotomy. We therefore investigated only examinations requested by general practitioners (GPs) to provide data from sitting patients. Methods: Weekly and monthly patient medians of serum albumin requested by GP for both male and female patients were calculated from the raw data obtained from three analysers in the hospital laboratory on examination of samples from those >18 years. The half-range of medians were applied as an estimate of the maximum bias. Further, the ratios between the two medians were calculated (females/males). Results: The medians for male and female patients were closely related despite considerable variation due to the current analytical variation. This relationship was confirmed by the calculated half-range for the monthly ratio between the genders of 0.44%, which surpasses the optimum analytical performance specification for bias of serum albumin (0.72%). The weekly ratio had a half-range of 1.83%, which surpasses the minimum analytical performance specifications of 2.15%. Conclusions: Monthly gender-partitioned patient medians of serum albumin are useful for monitoring of long-term analytical stability, where the gender medians are two independent estimates of changes in (delta) bias: only results requested by GP are of value in this application to ensure that all patients are sitting during phlebotomy.

Background: In lung adenocarcinoma, molecular profiling of actionable genes has become essential to set up targeted therapies. However, the feasibility and the relevance of molecular profiling from the cerebrospinal fluid (CSF) in the context of meningeal metastasis have been poorly assessed. Methods: We selected patients with stage IV lung adenocarcinoma harbouring metastatic cells in the CSF after cytological analysis. Seven samples from six patients were eligible for molecular testing of epidermal growth factor receptor ( EGFR ), V-Ki-ras2 Kirsten rat sarcoma viral oncogene homologue ( KRAS ), v-Raf murine sarcoma viral oncogene homologue B1 ( BRAF ) and human epidermal growth factor receptor 2 ( HER2 ) mutations using quantitative polymerase chain reaction (PCR) high-resolution melting curve analysis and Sanger sequencing after DNA extraction from the cell pellets of the CSF. Results: Five patients showed mutations in one or two actionable genes, two harboured an EGFR mutation (exons 19 and 21), one only a KRAS mutation, one both EGFR and KRAS mutations and one a BRAF mutation. In all cases, the results of mutation testing provided new major information for patient management, leading to therapeutic adaptation. CSF molecular analysis identified mutations not detected in other neoplastic sites for two patients. In one case, the EGFR p.Thr790Met was identified. CSF was also the only sample available for genetic testing for almost all patients at the time of disease progression. Conclusions: When cancer cells are present in the CSF, the molecular profiling from the cell pellets is relevant, as it can detect supplemental or different mutations compared to a previous analysis of the primitive tumour or plasma cell-free DNA and allows the adaptation of the treatment strategy.

Background: The distinction of type 1 and type 2 myocardial infarction (MI) is of major clinical importance. Our aim was to evaluate the diagnostic ability of absolute and relative conventional cardiac troponin I (cTnI) and high-sensitivity cardiac troponin T (hs-cTnT) in the distinction between type 1 and type 2 MI in patients presenting at the emergency department with non-ST-segment elevation acute chest pain within the first 12 h. Methods: We measured cTnI (Dimension Vista) and hs-cTnT (Cobas e601) concentrations at presentation and after 4 h in 200 patients presenting with suspected acute MI. The final diagnosis, based on standard criteria, was adjudicated by two independent cardiologists. Results: One hundred and twenty-five patients (62.5%)were classified as type 1 MI and 75 (37.5%) were type 2 MI. In a multivariable setting, age (relative risk [RR]=1.43, p=0.040), male gender (RR=2.22, p=0.040), T-wave inversion (RR=8.51, p<0.001), ST-segment depression (RR=8.71, p<0.001) and absolute delta hs-cTnT (RR=2.10, p=0.022) were independently associated with type 1 MI. In a receiver operating characteristic curve analysis, the discriminatory power of absolute delta cTnI and hs-cTnT was significantly higher compared to relative c-TnI and hs-cTnT changes. The additive information provided by cTnI and hs-cTnT over and above the information provided by the “clinical” model was only marginal. Conclusions: The diagnostic information provided by serial measurements of conventional or hs-cTnT is not better than that yielded by a simple clinical scoring model. Absolute changes are more informative than relative troponin changes.