Volume 50, Issue 1

HER-2/neu , also known as c-erbB-2/neu , is an oncogene located in chromosome 17 which encodes HER-2/neu, a transmembrane protein belonging to the EGFR family. The external domain of this protein is released by the cell and can be studied in serum by immunoassay. HER-2/neu in serum is a specific tumor marker and only slight elevations may be found in the absence of malignancy, mainly in association with liver diseases. Likewise, the highest concentrations of this oncoprotein are found in patients with breast cancer, but lower concentrations may be found in other malignancies, particularly ovarian, prostate and lung cancer (mainly adenocarcinomas). HER-2/neu assay sensitivity in patients with untreated primary loco-regional breast cancer is <10% and seems to be related to overexpression in tissue as well as to the most important prognostic factors: tumor size and nodal involvement. Serial HER-2/neu determinations after surgery seem to be useful in the early diagnosis of recurrence, mainly in patients with HER-2/neu overexpression in tissue, but additional studies are necessary to confirm these results. HER-2/neu sensitivity (proportion of patients with abnormal values) in patients with metastasis is around 40%–45%, with a clear relationship to tissue overexpression and to site (higher in visceral metastases) and number of metastases. The clinical utility of HER-2/neu in patients with advanced disease is mainly for therapeutic monitoring. Likewise, in most of the studies published, a relationship has been found between serum HER-2/neu levels (either pretreatment or at follow-up) with tumor response.

The declared “war on cancer” aimed to eradicate this disease using our knowledge of cancer cell biology to develop novel therapeutics. One such target of these novel therapies has been the human epidermal growth factor receptor 2 ( HER2 ) gene. Unique in the approach to abolishing function of this gene coded receptor, it was the first target of new monoclonal antibody therapy targeting the extracellular receptor and now also a target of small molecule drugs against the intracellular tyrosine kinase domain. In this instance, it was also one of the first applications of personalized medicine requiring companion diagnostics. In this manuscript, we review the biology and clinical applications of HER2 as a biomarker of disease and as a therapeutic target.

To date not much importance has been given to the sorting of examined properties (“tests”) in clinical laboratory reports. The present article contains a proposal about sorting the examined properties of clinical laboratory reports, in order to facilitate their interpretation to the requesting physicians. This proposal is mainly based on clinical and patho-physiological criteria. A set of groups of properties has been established according to the main clinical indications of each property. Some of these properties have several clinical indications and, consequently, have been included in more than one group. Some of these groups have been associated to other groups, so that the properties conforming them will always appear consecutively, since they are patho-physiologically related. Finally, an association between each group with the different medical specialities or areas of knowledge has been made, according to the clinical indications of each property. The groups of properties proposed are in concordance with their main clinical indications and their patho-physiological relationship. This ordering system gives priority, first, to the alarm (critical) values and, second, to the medical speciality or knowledge area of the requesting physician. This proposal can help the requesting physician to see first of all the most relevant clinical laboratory information related to her/his patient.

This document describes the application of the syntax, semantic rules and format of the NPU terminology for coded dedicated kinds-of-property in the various subject fields of the clinical laboratory sciences. The document sums up considerations and reasoning by the C-SC-NPU and collects the experience with the system through some 8 years of application in electronic health communication. Access to the NPU terminology in English is currently at www.labterm.dk, via the English download files from the Danish Release Centre under the National Board of Health. Updates to the terminology are usually presented once a month.

Background: Reliable and effective primary screening of mutation carriers is the key condition for common diagnostic use. The objective of this study is to validate the method high resolution melting (HRM) analysis for routine primary mutation screening and accomplish its optimization, evaluation and validation. Due to their heterozygous nature, germline point mutations of c- RET proto-oncogene, associated to multiple endocrine neoplasia type 2 (MEN2), are suitable for HRM analysis. Early identification of mutation carriers has a major impact on patients’ survival due to early onset of medullary thyroid carcinoma (MTC) and resistance to conventional therapy. Methods: The authors performed a series of validation assays according to International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidelines for validation of analytical procedures, along with appropriate design and optimization experiments. After validated evaluation of HRM, the method was utilized for primary screening of 28 pathogenic c- RET mutations distributed among nine exons of c- RET gene. Results: Validation experiments confirm the repeatability, robustness, accuracy and reproducibility of HRM. All c- RET gene pathogenic variants were detected with no occurrence of false-positive/false-negative results. Conclusions: The data provide basic information about design, establishment and validation of HRM for primary screening of genetic variants in order to distinguish heterozygous point mutation carriers among the wild-type sequence carriers. HRM analysis is a powerful and reliable tool for rapid and cost-effective primary screening, e.g., of c- RET gene germline and/or sporadic mutations and can be used as a first line potential diagnostic tool.

Background: A recent study reported that an 18-analyte multiplexed plasma panel of signaling proteins differentiated Alzheimer's disease (AD) from controls. This study measured mRNA expression for nine of these promising bio-markers in 23 AD patients and 23 age- and sex-matched controls. Methods: Total RNA was isolated from PaxGene RNA tubes. Relative mRNA expression levels of CCL5 [RANTES], CSF1, ICAM1, IGFBP6, IL1A, IL3, IL8, PDGFB and TNF were determined by Q-RT-PCR, with GAPDH as housekeeping gene. Results: A panel of five markers (CCL5, CSF1, ICAM1, IL8, TNF) with detectable expression levels in all individuals differed between AD patients and controls (p interaction <0.10). Especially, the relative expression level of CCL5 was lower in AD patients than in controls (p<0.005). Across groups, levels of both CCL5 and TNF were correlated to CSF levels of τ (r=0.39, r=0.32), pτ-181 (r=0.38, r=0.33), and MMSE (r=–0.31, r=–0.33, all p<0.05). Conclusions: The measured panel, and especially CCL5, could aid in the differentiation of AD from controls.

Background: Setting specifications for analytical quality is always difficult. The risk-management approach might be a way to do so. In this approach, the definition of the required analytical quality is based on the evaluation of patient risk. Risk derives from the probability of error and from the damage that such an error might cause. Methods: Eight Italian laboratories took part in this experiment. Measurements of glucose and total calcium were taken as examples. Analytical quality was evaluated using a specific ring trial with a frozen serum pool and by means of internal quality-control data. The total allowable error was defined according to biological variation specifications. The probability of error was extracted from the imprecision and comparative bias data of each laboratory. The damage caused by a wrong result was evaluated using the absolute probability judgment approach. Results: According to the iso-risk plots (standardized hyperboles on a graph where the x-axis represents damage and the y-axis represents probability) for glucose, all the laboratories were working with an analytical quality that guaranteed low risk for patients. On the contrary, for total calcium none of the laboratories exhibited sufficient quality to guarantee low risk for patients, the presence of bias being the most relevant problem. Conclusions: The results seem to demonstrate the applicability of the risk approach to the analytical phase, indicating a new possible way to define analytical quality targets.

Background: Qualitative diagnostic tests commonly produce false positive and false negative results. Smooth receiver operated characteristic (ROC) curves are used for assessing the performance of a new test against a standard test. This method, called c-statistic (concordance) has limitations. The aim of this study was to assess whether logistic regression with the odds of disease as an outcome and the test scores as covariate, can be used as an alternative approach, and to compare the performance of either of the two methods. Methods: Using as examples simulated by vascular laboratory scores we assessed the performance of logistic regression as compared to c-statistics. Results: The c-statistics produced areas under the curve (AUCs) of respectively 0.954 and 0.969 (standard errors 0.007 and 0.005), means difference 0.015 with a pooled standard error of 0.0086. This meant that the new test was not significantly different from the standard test at p=0.08. Logistic regression of these data with presence of disease as a dependent and vascular laboratory scores as an independent variable produced regression coefficients of 0.45 and 0.58 with standard errors of respectively 0.04 and 0.05. This meant that the new test was a significantly better predictor of disease than the standard test at p=0.04. Conclusions: Logistic regression with presence of disease as a dependent and test scores as an independent variable was better than c-statistics for assessing qualitative diagnostic tests. This may be relevant to future diagnostic research.

Background: Detection and quantification of monoclonal proteins is hampered when the monoclonal peak coincides with one of the regular bands in serum proteinelectrophoresis. The objective of this study was to evaluate four procedures for serum proteinelectrophoresis with respect to detection and quantification of monoclonal proteins. Methods: For 466 patient samples with a monoclonal protein, three variants of agarose gel electrophoresis (5-band, split-β and high resolution) and one variant of capillary electrophoresis were compared with the results of the routinely used agarose gel electrophoresis followed by immunofixation analysis using specific or pentavalent antisera. Results: In total, 310 patient samples were analyzed by the four methods, consisting of 295 samples with a monoclonal protein, seven with oligoclonal bands and eight without any bands. Suspicion of a monoclonal protein was raised in 295/256/256/232/265 of the samples using the reference/5-band/split-β/high resolution/capillary procedure. In 152/147/135/142/126 of the samples the concentration of monoclonal protein was >1.0 g/L and in 51/33/53/33/67 of the cases, the monoclonal protein was not separated from one of the normal protein zones. Conclusions: In high resolution agarose gel electrophoresis, monoclonal bands of low concentration often remain undetected. In split-β agarose gel electrophoresis as well as capillary electrophoresis monoclonal bands more often were not separated from the regular protein bands.

Background: Point-of-care testing (POCT) of prothrombin time, expressed as International Normalized Ratio (INR), is widely used to monitor patients in oral anticoagulation treatment. Guidelines recommend that POCT users should participate in an external quality assessment (EQA) scheme whenever available. The aim of this study was to investigate which European countries provide EQA for POCT INR and to compare how these schemes are organized. Methods: Thirty European countries were invited to participate in this study. Those who reported that they provide EQA for POCT INR filled in a questionnaire dealing with different aspects of their schemes. Results: Nineteen countries reported that they do not provide EQA for POCT INR, while 12 organizations from nine countries reported that they provide this service. Most of these countries circulate lyophilized samples with for the participants unknown target values. Samples with certified INR values and procedures using split samples with fresh patient samples are also used. The acceptability limits vary from 15% to 30%, and the total number of samples circulated per year varies from 1 to 12. Most of the countries organize educational activities together with their schemes. Conclusions: This study demonstrates that there is a wide variation in the way EQA for POCT INR is performed in Europe and that there are many European countries that do not provide this service. Even though our findings indicate that EQA for POCT INR draws some challenges, especially in providing suitable control materials, participation in such schemes is considered useful.

Background: Point-of-care testing (POCT) of fetal scalp blood lactate is used as an alternative for pH analysis. Lactate measurements have not been standardized and values vary with each device used. The aim of this study was to evaluate the performance of two POCT lactate meters for intrapartum use. Methods: Analytical performance of StatStrip Lactate (Nova Biomedical) and Lactate Pro (Arkray) was evaluated using CLSI EP10. Both POCT meters were compared with our lactate reference method (RapidLab 860; Siemens Healthcare Diagnostics) using fetal scalp and neonatal cord blood. Deming regression analysis was performed. Results: StatStrip Lactate coefficients of variation (CVs) were 5.1%, 5.0% and 2.6% at 0.9, 7.5 and 14.1 mmol/L lactate, respectively. CVs for Lactate Pro were 10.7%, 5.2% and 5.7% at 1.7, 4.1 and 6.4 mmol/L lactate, respectively. Consecutive lactate measurements in 37 fetal scalp and 122 cord blood samples revealed different test characteristics for the two POCT devices. In fetal scalp blood: StatStrip Lactate=1.13*RapidLab–0.39 (R 2 =0.907) and Lactate Pro=0.95*RapidLab–0.03 (R 2 =0.823). In cord artery blood: StatStrip Lactate=1.08*RapidLab–0.09 (R 2 =0.810) and Lactate Pro=0.72*RapidLab+0.59 (R 2 =0.807). Conclusions: Overall performance of both Lactate Pro and StatStrip Lactate was good, with StatStrip Lactate having smallest CVs and closest correlation to our reference method. Both StatStrip Lactate and Lactate Pro can be used as a lactate POCT device for obstetric use.

Background: Monitoring pain management drugs and frequently abused drugs is important for physicians to assess patient compliance. Liquid chromatography-tandem mass spectrometry offers high specificity needed for this purpose. In this report, a novel liquid chromatography-tandem mass spectrometry method for simultaneously monitoring 19 drugs/metabolites in urine was developed and validated. Methods: Sample preparation included hydrolysis, dilution and turbulent flow online extraction. Analysis was achieved by reverse phase liquid chromatography and triple-quadruple tandem mass spectrometry. Two fragment ions, one for quantification and the other for assuring identification, were monitored for each analyte. Results: No matrix effect or interference was observed. Lower limits of quantification ranged from 5 to 25 ng/mL. Within the linear range, analytical recovery was between 85.8% and 119.4%. Intra-assay and total coefficient of variations were between 0.2% and 12.7%. This method was compared with mass spectrometry methods offered by two other laboratories using 82 patient samples and 60 spiked urine samples showing 60%–100% agreement. The current method identified more positive samples for all analytes except THCA. The discrepancy in detection rates was primarily due to the different cut-offs used by the other laboratories. Conclusions: A sensitive and specific liquid chromatography-tandem mass spectrometry method was developed for measuring 19 drugs/metabolites in urine important for pain management clinics.

Background: The aim of the study was to define the analytical and diagnostic performance of the Labor Diagnostica Nord (LDN) 2-Met plasma ELISA assay for fractionated plasma metanephrines in the biochemical diagnosis of phaeochromocytoma. Methods: The stated manufacturer’s performance characteristics were assessed. Clinical utility was evaluated against liquid chromatography tandem mass spectrometry (LC-MS/MS) using bias, sensitivity and specificity outcomes. Samples (n=73) were collected from patients in whom phaeochromocytoma had been excluded (n=60) based on low probability of disease, repeat negative testing for urinary fractionated catecholamines and metanephrines, lack of radiological and histological evidence of a tumour and from a group (n=13) in whom the tumour had been histologically confirmed. Blood collected into k 2 EDTA tubes was processed within 30 min. Separated plasma was aliquoted (×2) and frozen at –40°C prior to analyses. One aliquot was analysed for plasma metanephrines using the LDN 2-Met ELISA and the other by LC-MS/MS. Results: The mean bias of –32% for normetanephrine (ELISA) when compared to the reference method (LC-MS/MS) makes under-diagnosis of phaeochromocytoma likely. The sensitivity of the assay (100%) was equal to the reference method, but specificity (88.3%) lower than the reference method (95%), making it less than optimum for the biochemical diagnosis of phaeochromocytoma. Conclusions: Plasma-free metanephrines as measured by Labor Diagnostica Nord (LDN) 2-Met ELISA do not display test characteristics that would support their introduction or continuation as part of a screening protocol for the biochemical detection of phaeochromocytoma unless the calibration problem identified is corrected and other more accurate and analytically specific methods remain unavailable.

Background: In the diagnosis of celiac disease (CD), serum assays for anti-endomysium (EMA) and anti-transglutaminase (anti-tTG) antibodies have excellent diagnostic accuracy. However, these assays are less sensitive in young pediatric patients. Recently, a new ELISA test using deamidated gliadin peptides (DGP) as antigen has proved to be very sensitive and specific even in pediatric patients. In addition, anti-actin IgA antibodies (AAA) is another test that can be used in CD patients because antibody concentrations correlate with the degree of villous atrophy. This study evaluated the clinical accuracy of anti-tTG, EMA, AGA, anti-DGP and AAA and the effectiveness of these in different combinations for diagnosing CD in a large cohort of pediatric patients. Methods: Sera of 150 children under 6 years of age were tested: 95 patients had a diagnosis of CD, while 55 patients who did not suffer from CD were used as controls. Anti-DGP IgA/IgG and AAA were assayed with ELISA kits, while anti-tTG IgA/IgG and AGA IgG/IgA were assayed using a quantitative fluoroimmunoassay. The EMA test was conducted by indirect immunofluorescence. Results: Seventy-six of 95 (80%) CD patients were positive for DGP IgA and/or tTG IgA. Eighty of 95 (84.2%) patients were positive for DGP IgG and/or tTG IgA. None of the controls were positive for these antibodies. Eighty-four of 95 (88.4%) patients and 8/55 (14.5%) controls were positive for AAA and/or anti-tTG IgA. Conclusions: In very young children, association of anti-tTG IgA with anti-DGP IgG is the best test combination for diagnosing CD, yielding a cumulative sensitivity of 84.2% and a specificity of 100%.

Background: Adult-type hypolactasia is caused by genetic lactase non-persistence. It is the most common cause of lactose intolerance, which results in gastrointestinal symptoms after ingestion of dairy products. Currently, lactose intolerance is investigated by the hydrogen breath test (HBT), which is considered the preferred diagnostic test. Adult-type hypolactasia may also be diagnosed by genotyping. The single nucleotide polymorphism –13910C>T, which is located upstream of the lactase gene ( LCT ), is tightly associated with lactase persistence. Several other variants, mostly in non-European populations, can also lead to lactase persistence. This study investigated the accuracy of a modified, recently proposed algorithm which includes genotyping for the diagnosis of adult-type hypolactasia in a patient population with unexplained abdominal complaints. Methods: In 126 patients with unexplained abdominal symptoms or who were suspected to have adult-type hypolactasia, LCT genotyping by melting curve analysis on a LightCycler was performed. Those patients with CC -13910 genotype (indicating loss of lactase expression) were directly referred to a dietician for a lactose-free diet. Those identified as CT -13910 or TT -13910 genotype underwent a HBT. Those who tested positive for hydrogen were also referred to a dietician for a lactose-free diet. The response to diet modification was recorded. Results: Genotype prevalences were: CC -13910 : 43 (34.1%); CT -13910 : 48 (38.1%); TT -13910 : 33 (26.2%); TG -13915 : 2 (1.6%). Eleven of 48 (23%) patients with CT -13910 -genotype and 1/33 (3%) patients with TT -13910 -genotype had a positive hydrogen breath test. They all improved after a lactose-free diet. Four of 43 (9%) patients with CC -13910 -genotype still had symptoms after a lactose-free diet. Conclusions: The results show that lactase-genotype testing can be used as a first step to diagnose lactose intolerance in a patient population with unexplained abdominal complaints. It accurately identifies the group of patients sensitive to lactose, those who need further breath testing and those in whom adult-type hypolactasia can be excluded with high probability without performing a HBT. This algorithm would save hydrogen breath testing in more than 50% of the patients who present with unexplained abdominal symptoms.

Background: Matrix Gla-protein (MGP) is a calcification inhibitor produced by cartilage and vessel walls. Arthritis is defined by inflammation, cartilage and bone destruction/formation and articular calcifications. Our objectives were to evaluate ucMGP levels in synovial fluid (SF) in arthritis patients and to investigate the relationship between local and circulating ucMGP and their association with age and inflammation. Methods: Arthritis patients (n=26) with knee joint effusion and controls (n=30) underwent an ultrasonographic knee examination for articular calcifications assessment. Patients were divided into inflammatory and non-inflammatory groups. ucMGP levels were determined in serum and SF using a competitive ELISA assay. Results: Within the arthritis patients, the inflammatory group had the lowest ucMGP serum levels, and the highest levels of synovial ucMGP. Furthermore, the inflammatory group had significantly (p<0.05) higher RucMGP (synovial ucMGP/serum ucMGP*100) than the non-inflammatory group [36 (17–69) vs. 24 (5–55)], and this parameter positively correlated (r=0.4; p<0.05) with the erythrocyte sedimentation rate (ESR). No correlation was found between age and local or circulating ucMGP in patients and controls. Conclusions: The ucMGP assay can be used for determination of MGP in SF, and combined assessment of ucMGP in serum and SF could potentially serve as a joint inflammatory marker in arthritis patients.

Background: This study evaluated the diagnostic performance of naturally purified allergen-molecules compared to that of allergen-extracts for house dust mite, cat dander epithelium and dog dander. Methods: In vitro tests for allergen-specific IgE were performed on the IMMULITE ® 2000 in serum samples from 66 allergic patients. Results: House dust mite: specificity for the allergen-extract (D1) and the allergen-molecules (nDer p 1, nDer f 1, nDer p 2 and nDer f 2) is comparable. The allergen-extract has a significantly higher sensitivity (100%) and total agreement (TA) (93%) relative to sensitivity (57%–70%) and TA (76%–81%) of the individual allergen-molecules. Cat dander epithelium: sensitivity (90%), specificity (96%) and TA (94%) of the allergen-molecule (nFel d 1) are comparable to those of the allergen-extract (E1). Dog dander: The allergen-molecule (nCan d 1) and allergen-extract (E5) have comparable specificity and TA. The allergen-extract has a lower sensitivity (52%) than the allergen-molecule (71%), although not significant (p=0.125). Conclusions: There is no diagnostic benefit of using allergen-molecules instead of allergen-extracts for initial allergy screening on cat dander epithelium and dog dander. However, use of these allergen-molecules might contribute to better standardization of the specific IgE tests. The studied allergen-molecules for house dust mite are of minor diagnostic value, because of loss of sensitivity.

Background: The potential use of cystatin C has recently emerged to evaluate kidney function following transplantation. Analytical performance of a particle-enhanced turbidimetric immunoassay (PETIA) using Dako Cytomation Cystatin C reagents on an Olympus AU640 ® analyzer was evaluated. Clinical relevance was determined by comparison with a reference method in a kidney transplant cohort. Methods: Repeatability and reproducibility were carried out for four levels of cystatin C. Linearity was done by successive dilution of plasma samples with high level of cystatin C. Comparison study was performed against the particle-enhanced nephelemetry immunoassay (PENIA) using Siemens reagents on BNII ® system. Values of the glomerular filtration rate (GFR) estimated from several predictive cystatin C- and creatinine-based equations were compared to the GFR measured by isotopic method ( 99m Tc-DTPA). These predictive algorithms were analyzed with respect to bias, precision and accuracy. Results: Total intra-assay and inter-assay variation coefficients were below 4% at the four levels tested. Values obtained with Dako-PETIA on AU640 ® were correlated with the Siemens-PENIA method (Dako-Olympus=0.88 Siemens+0.17). The cystatin C alone and the creatinine-cystatin C combined equation allowed reliable assessment of GFR in our population of renal transplants. The cystatin C-based or the combined equation moderately improved determination of GFR (about 10% compared to 175MDRD for classification into the correct K/DOQI CKD stages). Conclusions: The use of algorithms based on cystatin C and creatinine could provide a reliable estimate of the GFR in kidney transplantation. Standardization of cystatin C assays could further improve the predicting value of cystatin C in transplantation.

Background: Aution Max AX-4030, a test strip analyzer recently introduced to the market, represents an upgrade of the Aution Max AX-4280 widely employed for urinalysis. This new instrument model can allocate two different test strips at the same time. In the present study the two instruments have been compared together with the usage of Uriflet 9UB and the recently produced Aution Sticks 10PA urine strips, the latter presenting an additional test area for the measurement of urinary creatinine. Methods: Imprecision and correlation between instruments and strips have been evaluated for chemical-physical parameters. Accuracy was evaluated for protein, glucose and creatinine by comparing the semi-quantitative results to those obtained by quantitative methods. The well-known interference effect of high ascorbic acid levels on urine glucose test strip determination was evaluated, ascorbic acid influence was also evaluated on protein and creatinine determination. Results: The two instruments have demonstrated comparable performances: precision and correlation between instruments and strips, evaluated for chemical-physical parameters, were always good. Furthermore, accuracy was always very good: results of protein and glucose semi-quantitative measurements resulted to be highly correlated with those obtained by quantitative methods. Moreover, the semi-quantitative measurements of creatinine, employing Aution Sticks 10PA urine strips, were highly comparable with quantitative results. Conclusions: 10PA urine strips are eligible for urine creatinine determination with the possibility of correcting urin-alysis results for urinary creatinine concentration, whenever necessary and calculating the protein creatinine ratio. Further studies should be carried out to evaluate effectiveness and appropriateness of the usage of creatinine semi-quantitative analysis.

Background: Serum total calcium is becoming a widely used test when screening for hyperparathyroidism (HPT) and other causes of hypercalcemia, even if serum calcium is tightly regulated in the body it is unclear whether the reference values are correct for tests taken at different times of the day or for individuals with altered sleep patterns. Thus, the aim was to investigate how timing of testing and sleep affects serum calcium. Methods: The diurnal variation of total calcium in serum during night-time and day-time conditions was studied in seven healthy volunteers. Serum samples for calcium measurements were collected every hour (48 samples per individual) to evaluate the effect of sampling times, sleep and food intake on the test results. Results: The median intra-individual coefficients of variations for calcium were 3.3% during night-time sleep and 2.8% during day-time sleep conditions. There was a clear diurnal variation in serum calcium, with a trough at 08.00 h in the morning after night-time sleep and a difference of approximately 0.07 mmol/L between trough and peak. Calcium was lower around the end of the sleep periods, for both night-time and day-time sleep. Food intake did not affect calcium concentrations. Conclusions: Evaluation of serum calcium results should take diurnal variation into account and allow slightly higher calcium values in the afternoon in comparison with samples collected in the morning.

Background: To evaluate and compare the detection efficacy of serum hepatitis B virus (HBV) markers by two immunoassays: electrochemiluminescence immunoassay (ECLIA) and enzyme-linked immunosorbent assay (ELISA). Methods: ECLIA and ELISA were used to analyze 359 serum samples, including 64 HBsAg/anti-HBs coexistence serological pattern samples (samples positive for both HBsAg and anti-HBs), 24 HBeAg/anti-HBe coexistence serological pattern samples (samples positive for both HBeAg and anti-HBe), and 271 normal serological pattern samples (negative for either of the combinations). Results: In the normal serological pattern samples, the concordance rates of the two methods in detecting serum HBV markers were as follows: 97.05% for HBsAg, 92.62% for anti-HBs, 100% for HBeAg, 76.75% for anti-HBe, and 58.67% for anti-HBc. The differences in the qualitative criteria for anti-HBc and anti-HBe were primarily responsible for the discrepancy between the two methods (κ-values of 0.657 and 0.253, respectively). Most weak positive results, determined by ECLIA, were negative determined by ELISA, whereas the results of HBsAg, anti-HBs, and HBeAg detection were generally consistent. In the HBsAg/anti-HBs coexistence serological pattern samples, the concordance rates of HBsAg and anti-HBs detection were 98.44% and 34.38%, respectively. The positive rate of ELISA does not vary as the COI (cut-off index) varies which was determined by ECLIA; in the HBeAg/anti-HBe coexistence serological pattern samples, the concordance rates of HBeAg and anti-HBe detection were 45.83% and 79.17%, respectively. Most weak positive results, determined by ECLIA, were negative when determined by ELISA. Conclusion: The discrepancies between the two assays in normal serological patterns samples and HBeAg/anti-HBe coexistence serological pattern samples were mostly due to the different sensitivity of the two assays, but for the HBsAg/anti-HBs coexistence serological pattern samples, the discrepancy was not caused by the different sensitivity. It is the difference in determining anti-HBs which led to the discrepancy.

Background: Third generation troponin assays should aid in the rule-out of acute myocardial infarction (AMI). The study aim was to assess the capability of admission measurement of ultra-sensitive troponin I (TnI-Ultra) to exclude AMI from other myocardial injury. Methods: The first TnI-Ultra sample from 856 patients at presentation to the Emergency Department and subsequent admission to the Cardiac Care Unit were considered in this case series. Myoglobin was simultaneously detected in 684 patients. Results: The sensitivity of the first single TnI-Ultra level was 82.5% in overall AMI, and similar in ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI), admitted, respectively at 3 and 8 h from symptoms. The diagnostic capability of a first single TnI-Ultra level was poor for both STEMI and NSTEMI to discriminate and rule-out overall AMI from myocardial injury, with an area under the receiver-operating curve of 0.65 and a negative likelihood ratio of 0.55. Adopting an optimal test threshold or adding myoglobin detection did not improve TnI-Ultra performances. Conclusions: The capability of a first single TnI-Ultra level to exclude AMI from other myocardial injury in early and late presenters is poor. Addition of myoglobin assay offered no further improvement and was not considered useful.

Background: The aim of the present study was to evaluate the role of extracellular matrix-associated glycosaminoglycans (GAGs), connective tissue growth factor (CTGF), angiogenic vascular endothelial growth factor (VEGF) and inflammatory factors (MCP-1, CD40, IFN-γ) in the development of diabetic nephropathy in type 1 diabetes (T1DM). Methods: Plasma and urine samples from 30 T1DM patients and 20 healthy controls were used to measure the levels of CTGF, VEGF, MCP-1, CD40 and IFN-γ by ELISA. Plasma and urine GAGs were measured using a spectrophotometric method. Results: Plasma levels of GAGs, CD40 and MCP-1 and urine levels of GAGs and CTGF were significantly elevated in normoalbuminuric T1DM patients. A tendency to higher plasma VEGF levels was found in patients compared to controls. The urine/plasma GAGs ratio of T1DM patients was almost similar to that of healthy subjects (HS), whereas the urine/plasma CTGF ratio was about three times greater in diabetic patients compared to HS. Conclusions: Conclusively, increased GAGs and CTGF excretion are evident in T1DM normoalbuminuric juveniles, possibly reflecting early renal injury signs, before the initiation of albuminuria.

No abstract available