Volume 54, Issue 4

The 21st century challenge is to redesign healthcare systems to be safe, efficient, effective, timely, equitable and patient-centred. Although laboratory medicine is integral to many of these objectives involving prevention, diagnosis, treatment, and managing disease of patients, it suffers from poor visibility as a medical discipline and as a profession and fewer rewards for educational efforts when compared to other medical disciplines. Laboratory scientists are often perceived as managing machinery and equipment, but conversely they need to take a position of shared clinical leadership, showing the role of laboratory tests to guarantee optimal care for patients. This is however challenging because of some reluctance by laboratory professionals to involve themselves in test structuring and requesting and in the inspection of work as it arrives because it is assumed that all requests are clinically necessary; there is a poor communication and integration between clinical wards and laboratory; and, importantly, there is the need for an excellent cultural and scientific background of laboratory professionals for implementing outcome research and to act as knowledge managers and skilled clinical consultants. By combining the unique talent of performing quality laboratory assays with knowledge of the pathophysiologic rationale behind the tests, laboratory professionals have the expertise to advise their clinical colleagues in regard to the appropriate test selection and interpretation of laboratory results, thereby creating opportunities to define the added value and the pivotal role of laboratory medicine on healthcare delivery.

Harmonisation and risk management policies represent key-issues in modern laboratory medicine as they focus on a more patient-centred delivery of laboratory information based on the recognition of the importance of all steps of the total testing process (TTP) for assuring quality and patient safety. However, a further essential step in project aiming to improve the value of laboratory medicine becomes the assessment of the impact of testing on patient-important outcomes. The grading of recommendations assessment, development and evaluation (GRADE) evidence to decision (EtD) frameworks may provide a systematic and transparent approach for translating the best clinical evidence available into healthcare decisions and recommendations. GRADE is a tool appropriate not only for evaluating test accuracy but also for clinical impact, such as mortality, morbidity, symptoms, and quality of life and therefore it should be applied to the outcome research in laboratory medicine. The application of GRADE requires the recognition that a recommendation about the use of test results should result from a balance between the desirable and the undesirable consequences, including non-health related consequences such as resource utilisation, feasibility, acceptability, equity and other factors. GRADE EtDs, represents a fundamental step in projects designed to improve care quality. Patient-physician-laboratory feedback can be assured through the GRADE process, where the team developing the recommendations should include the “three-parties” representatives; clinicians, laboratorians and patient/consumers. This ensures that the laboratory-patient interaction should not be a one-way process only (information from laboratory to patient) but a two-way process, incorporating patient expectations and feedback.

Background: Accreditation is a valuable resource for medical laboratories. The development of quality systems based on ISO 15189 has taken place in many laboratories in the European countries but data about accreditation remain scarce. The EFLM Working Group “Accreditation and ISO/CEN standards” conducted a survey that reviews the current state of the accreditation process in European countries. Methods: An on-line questionnaire was addressed to delegates of 39 EFLM scientific societies in March 2014. One answer by country was taken into account. The survey was dealing with mandatory status, number of accredited medical laboratories in each country, possibility of flexible scope and concerned medical fields. The status of point-of-care testing (POCT) in each country was also studied. Results: Twenty-nine responses (74%) were registered. All the assessed countries (100%) have begun an accreditation process in various ways. All the national accreditation bodies (NAB) offer or are working to offer an ISO 15189 accreditation. The accreditation process most often concerns all phases of the examination and various medical fields. Medical laboratories are responsible for POCT in 20 (69%) countries. The accreditation process for POCT, according to ISO 15189 and ISO 22870, is also developing. Conclusions: While there are several variations in the approaches to accreditation of medical laboratories in the European countries, the ISO 15189 accreditation project has been widely accepted. The use of a unique standard and the cooperation among countries due to scientific societies, EFLM, accreditation bodies and EA enable laboratory professionals to move toward uniform implementation of the accreditation concept.

Background: Structural hemoglobinopathies do not usually have a clinical impact, but they can interfere with the analytical determination of some parameters, such as the glycated hemoglobin in diabetic patients. Thalassemias represent a serious health problem in areas where their incidence is high. The defects in the post-translational modifications produce hyper-unstable hemoglobin that is not detected by most of electrophoretic or chromatographic methods that are available so far. Methods: We studied seven patients who belong to six unrelated families. The first two families were studied because they had peak abnormal hemoglobin (Hb) during routine analytical assays. The other four families were studied because they had microcytosis and hypochromia with normal HbA 2 and HbF without iron deficiency. HbA 2 and F quantification and abnormal Hb separation were performed by chromatographic and electrophoretic methods. The molecular characterization was performed using specific sequencing. Results: The Hb Puerta del Sol presents electrophoretic mobility and elution in HPLC that is different from HbA and similar to HbS. The electrophoretic and chromatographic profiles of the four other variants are normal and do not show any anomalies, and their identification was only possible with sequencing. Conclusions: Some variants, such as Hb Valdecilla, Hb Gran Vía, Hb Macarena and Hb El Retiro, have significant clinical impact when they are associated with other forms of α-thalassemia, which could lead to more serious forms of this group of pathologies as for HbH disease. Therefore, it is important to maintain an adequate program for screening these diseases in countries where the prevalence is high to prevent the occurrence of severe forms.

Background: The aim of the study was to develop a method for sweat chloride (Cl) quantification using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to present to the Joint Committee for Traceability in Laboratory Medicine (JCTLM) as a candidate reference method for the diagnosis of cystic fibrosis (CF). Methods: Calibration standards were prepared from sodium chloride (NaCl) to cover the expected range of sweat Cl values. Germanium (Ge) and scandium (Sc) were selected as on-line (instrument based) internal standards (IS) and gallium (Ga) as the off-line (sample based) IS. The method was validated through linearity, accuracy and imprecision studies as well as enrolment into the Royal College of Pathologists of Australasia Quality Assurance Program (RCPAQAP) for sweat electrolyte testing. Results: Two variations of the ICP-MS method were developed, an on-line and off-line IS, and compared. Linearity was determined up to 225 mmol/L with a limit of quantitation of 7.4 mmol/L. The off-line IS demonstrated increased accuracy through the RCPAQAP performance assessment (CV of 1.9%, bias of 1.5 mmol/L) in comparison to the on-line IS (CV of 8.0%, bias of 3.8 mmol/L). Paired t-tests confirmed no significant differences between sample means of the two IS methods (p=0.53) or from each method against the RCPAQAP target values (p=0.08 and p=0.29). Conclusions: Both on and off-line IS methods generated highly reproducible results and excellent linear comparison to the RCPAQAP target results. ICP-MS is a highly accurate method with a low limit of quantitation for sweat Cl analysis and should be recognised as a candidate reference method for the monitoring and diagnosis of CF. Laboratories that currently practice sweat Cl analysis using ICP-MS should include an off-line IS to help negate any pre-analytical errors.

Background: The quality of hemoglobin A 1c measurement is very important in the management of diabetes. A reference system has been established by the IFCC Working Group on HbA 1c Standardization. We did some modification of the IFCC Reference Measurement Procedure with MS detection which significantly decreased the analysis time and improved the precision of the analytes by off-line HPLC separation and liquid chromatography-tandem mass spectrometry (LC/MS/MS) analysis. Methods: The samples were prepared and enzymatically cleaved according to the IFCC HbA 1c reference measurement procedure. Then the digest solution was injected to a reversed phase HPLC for purification and a clean fraction was collected. The fraction was analyzed by liquid chromatography-tandem mass spectrometry with an isocratic elution on a C18 column. Liner regression was used to determine the concentration of HbA 1c . Results: The total analysis time which includes the off-line HPLC separation and the LC/MS/MS analysis was reduced by at least 65% compared to the existing IFCC method. The transitions of m / z 348.4→237.2 and m / z 429.4→245.2 were selected for quantification of non-glycated and glycated hexapeptide. Fifty seven hemolysate samples used in recent 3-years’ IFCC HbA 1c inter-laboratory studies (2012–2014) were analyzed by the LC/MS/MS procedure for method validation. The CV S were between 0.16% and 1.87% for 4 measurements per sample in the concentration range for HbA 1c between 30.4 and 145.8 mmol/mol. The relative bias of the LC/MS/MS method was varied from -3.21% to 2.47% compared to the IFCC network assigned values. Conclusions: This method is an efficient and reliable procedure for the determination of HbA 1c . After thorough evaluation within the IFCC Network this modification may be implemented in the IFCC RMP for HbA 1c with MS detection.

Background: Procalcitonin (PCT) is increasingly being used for the diagnostic and prognostic work up of patients with suspected infections in the emergency department (ED). Recently, B·R·A·H·M·S PCT direct, the first high sensitive point-of-care test (POCT), has been developed for fast PCT measurement on capillary or venous blood samples. Methods: This is a prospective, international comparison study conducted in three European EDs. Consecutive patients with suspicion of bacterial infection were included. Duplicate determination of PCT was performed in capillary (fingertip) and venous whole blood (EDTA), and compared to the reference method. The diagnostic accuracy was evaluated by correlation and concordance analyses. Results: Three hundred and three patients were included over a 6-month period (60.4% male, median age 65.2 years). The correlation between capillary or venous whole blood and the reference method was excellent: r 2 =0.96 and 0.97, sensitivity 88.1% and 93.0%, specificity 96.5% and 96.8%, concordance 93% and 95%, respectively at a 0.25 μg/L threshold. No significant bias was observed (–0.04 and –0.02 for capillary and venous whole blood) although there were 6.8% and 5.1% outliers, respectively. B·R·A·H·M·S PCT direct had a shorter time to result as compared to the reference method (25 vs. 144 min, difference 119 min, 95% CI 110–134 min, p<0.0001). Conclusions: This study found a high diagnostic accuracy and a faster time to result of B·R·A·H·M·S PCT direct in the ED setting, allowing shortening time to therapy and a more wide-spread use of PCT.

Background: Intensive care units, operating rooms, emergency departments, and neonatology units need rapid measurements of blood gases, electrolytes, and metabolites. These analyses can be performed in a central laboratory or at the clinic with traditional or compact cassette-type blood gas analyzers such as the epoc blood gas testing system for analyzing whole blood samples at the bedside. In this study, the performance and interchangeability of a hand-held epoc blood gas analyzer was evaluated. Methods: The analytical performance of the epoc analyzer was evaluated by determining within-and between-run precisions. The accuracy of the epoc analyzer was assessed by comparing patient results from the device with those obtained with the Siemens Rapidlab 1265 and Rapidpoint RP500 and Siemens Dimension Vista and Sysmex XE-2100 analyzers. The following parameters were measured: pH, pCO 2 , pO 2 , Hb (calc), Na + , K + , iCa 2+ , glucose, and lactate. Results: The CV% of the epoc’s between-day imprecision for the various parameters varied from 0.4 to 8.6. The within-run imprecision CV% varied from 0.6 to 5.2. The squared regression coefficient (R 2 ) between the epoc and RL1265 varied from 0.94 to 0.99, with the exception of Na + and Ca 2+ (R 2 ≥0.82). The correlation (R 2 ) of Na + and K + between epoc and Dimension Vista was 0.73 and 0.89, respectively. The correlation (R 2 ) of Hb between the epoc and the XE-2100 analyzer was 0.94. Conclusions: With most of the measured blood gas parameters, the epoc analyzer correlated well with reference techniques. The epoc analyzer is suitable for rapid measurement of the blood gases, the electrolytes, and the metabolites in the ICU.

Background: This study aimed to determine whether patients with lower abdominal symptoms can be investigated quickly using results of faecal haemoglobin concentration (f-Hb) measurements, and whether this test could form part of a diagnostic pathway for significant colorectal disease. Methods: Nine hundred and nine consecutive patients referred from primary care for colonoscopy were invited: 507 submitted samples for f-Hb measurement with a quantitative faecal immunochemical test for haemoglobin (FIT) (HM-JACKarc, Kyowa-Medex, Japan) and a diagnostic colonoscopy was completed in 484 patients. Results: Colorectal cancer (CRC), higher risk adenoma (HRA), inflammatory bowel disease (IBD) and/or colitis was found in 45 patients (9.3%); these had significantly higher (p<0.0001) f-Hb than the group of 243 with normal colonoscopy plus the 196 patients with less significant clinical findings. The 11 (2.2%) patients with CRC all had f-Hb >190 μg Hb/g faeces. Using a f-Hb cut-off of 10 μg Hb/g faeces, for the group with CRC or HRA or IBD or colitis, sensitivity was 68.9%, specificity 80.2%, positive predictive value (PPV) 26.3% and negative predictive value (NPV) 96.2%. Sensitivity and NPV were 100% for CRC suggesting f-Hb is a good rule-in test for CRC. Of the 243 patients with normal colonoscopy, 81.2% had f-Hb<10 μg Hb/g faeces. Conclusions: The high NPV for significant colorectal diseases suggests that f-Hb could be used as a rule-out test in this context. Potential exists for using f-Hb measurements to investigate symptomatic patients and guide the use of colonoscopy resources: detailed algorithms for the introduction of f-Hb measurements requires further exploration.

Background: Macroprolactinaemia is a major cause of hyperprolactinaemia. The detectability of macroprolactin varies widely among different immunoassay systems, but the causes are not fully known. This study aimed to identify the factors influencing the detectability of macroprolactin by immunoassay systems. Methods: The study included 1544 patients who visited an obstetric and gynaecological hospital. Macroprolactinaemia was screened using the polyethylene glycol (PEG) method and confirmed using gel filtration chromatography and the protein G method. The prolactin (PRL) values determined by enzyme immunoassay (EIA) were compared with those of a chemiluminescence immunoassay system (Centaur) that is known to cross-react the least with macroprolactin. Results: Macroprolactinaemia was found in 62 of 1544 patients (4.02%) who visited an obstetric and gynaecological hospital. The ratio of EIA-determined total PRL to free PRL in the supernatant after PEG precipitation was significantly elevated in all 62 serum samples with macroprolactin compared to those in 1482 serum samples without macroprolactin. In contrast, the ratio of Centaur-determined total PRL to free PRL was significantly elevated in 32 serum samples (group 1) and was within the normal range in 30 (group 2) of 62 serum samples with macroprolactin. The prevalence of non-IgG-type macroprolactin was significantly higher in group 1 than in group 2. Centaur diagnosed hyperprolactinaemia less frequently than EIA (n=2 vs. 16) in 62 patients with macroprolactinaemia. Those two hyperprolactinaemic patients diagnosed by Centaur had non-IgG-type macroprolactin. Conclusions: Macroprolactinaemia was present in 4% of patients visiting an obstetric and gynaecological hospital. The nature of macroprolactin (IgG-type or non-IgG-type) may partly explain why macroprolactin detectability varies among different immunoassay systems.

Background: The aim of this study was to compare different analytical methods that are currently in use in the Netherlands for the measurement of whole blood vitamin B6. Methods: This method comparison study consisted of two separate parts. (1) Four laboratories participated in a pilot study in which the commercial Chromsystems and INstruchemie method, and a laboratory developed liquid chromatography-tandem mass spectrometry (LC-MS/MS) method and HPLC method were compared. Sixty-nine frozen whole blood samples and six lyophilized whole blood samples were used for comparison. (2) In the nationwide part of the study, 49 laboratories participated in the analysis of three identical sets of two whole blood samples of which one set was freshly analyzed, one set was analyzed after storage at −20 °C and one set was analyzed after lyophilization. Results: In both parts of the study, the HPLC and LC-MS/MS methods showed equivalent results for all sample types tested. The Chromsystems method showed a positive bias of 45% (pilot study) and 30% (nationwide study) towards the LC-MS/MS method when fresh or frozen samples were used. The measurement of lyophilized samples showed no differences between the methods. The results of the INstruchemie method were inconclusive due to the low number of participants. Conclusions: The different analytical methods for measuring vitamin B6 produce different results when whole blood patient samples are measured. The recognition of a reference method or the development of suitable reference materials and quality control materials might serve as a first step towards improved standardization or harmonization of the whole blood vitamin B6 assay.

Background: We evaluated the analytical and clinical performance of the new Lumipulse ® G 25-OH vitamin D assay from Fujirebio, and compared it to a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method and three other commercial automated assays. Methods: Total 25 hydroxy vitamin D (25(OH)D) levels were measured in 100 selected serum samples from our routine analysis with Fujirebio 25(OH)D assay. The results were compared with those obtained with LC-MS/MS and three other automated 25(OH)D assays (Abbott, Beckman, and Roche). The accuracy of each assay tested was evaluated against a Labquality reference serum panel for 25(OH)D (Ref!25OHD; University of Ghent). Results: Intra- and inter-day imprecision of the Fujirebio 25(OH)D assay was <5%. Fujirebio 25(OH)D assay showed the highest correlation among the assays tested with the LC-MS/MS method (R=0.986). The mean relative bias obtained was –15.6% (Fujirebio), –12.7% (Beckman), –2.1% (Abbott) and 9.7% (Roche) as compared to LC-MS/MS. Comparison with the Labquality certified reference serum panel yielded a mean bias of –11.8% (Fujirebio), –14.1% (Beckman), 4.4% (Abbott) and 3.2% (Roche), respectively. Compared to LC-MS/MS, the sensitivity of different methods in detecting vitamin D insufficiency (<50 nmol/L) varied from 100% for the Fujirebio assay to 72.7% for Roche, and specificity ranged from 94.4% for Roche to 87.6% for Beckman. Conclusions: The Lumipulse G 25-OH vitamin D assay from Fujirebio demonstrated a good correlation with LC-MS/MS and some immunoassays. The performance of the assay is well-suited for routine 25(OH)D measurement in clinical serum samples. A correction for the observed negative bias vs. LC-MS/MS could be considered.

Background: Purine nucleoside phosphorylase (PNP) deficiency has been recently introduced in the newborn screening program in Tuscany. In order to improve the PNP screening efficiency, we developed a 2nd tier test to quantify PNP primary markers deoxyguanosine (dGuo) and deoxyinosine (dIno). Methods: Dried blood spots (DBS) samples were extracted with 200 μL of methanol and 100 μL of water (by two steps). Internal standards were added at a final concentration of 10 μmol/L. After extraction, samples were analysed by LC-MS/MS. The chromatographic run was performed in gradient mode by using a Synergi Fusion column. Results: The assay was linear over a concentration range of 0.05–50 μmol/L (R 2 >0.999) for dGuo and 0.5–50 μmol/L (R 2 >0.998) for dIno. Intra- and interassay imprecision (mean CVs) for dIno and dGuo ranged from 2.9% to 12%. Limit of quantitaion (LOQ) were found to be 0.05 μmol/L and 0.5 μmol/L for dGuo and dIno, respectively. The reference ranges, obtained by measuring dGuo and dIno concentrations on DBS, were close to zero for both biomarkers. Moreover, DBS samples from seven patients with confirmed PNP were retrospectively evaluated and correctly identified. Conclusions: The LC-MS/MS method can reliably measure dIno and dGuo in DBS for the diagnosis of PNP. Validation data confirm the present method is characterised by good reproducibility, accuracy and imprecision for the quantitation of dIno and dGuo. The assay also appears suitable for use in monitoring treatment of PNP patients.

Background: Cigarette smoking is a major risk factor for several chronic diseases. Epidemiological data indicate the use of smokeless tobacco (ST) is associated with significantly lower risk for smoking-related diseases compared to cigarettes. Several biomarkers of exposure (BioExp) and effect (BioEff) associated with smoking and use of moist snuff (ST) were evaluated. Methods: A single site, cross-sectional clinical study enrolled three groups of generally healthy male smokers (SMK), moist snuff consumers (MSC), and non-tobacco consumers (NTC), and several BioExp and BioEff were evaluated. Results: Blood and urinary BioExp, including total nicotine equivalents and tobacco-specific nitrosamines, were higher in MSC compared to SMK. Biomarkers of combustion-related toxicants and cadmium were elevated in SMK. Elevated levels of some BioEff associated with oxidative stress (urinary isoprostanes and leukotriene E4), inflammation (white blood cell count), platelet activation (thromboxane metabolites), and lipid metabolism (apolipoprotein B100 and oxidized low-density lipoprotein) were observed in SMK relative to NTC and MSC (all p<0.05). The non-smoking groups (MSC and NTC) showed similar levels of combustion-related BioExp and BioEff. Conclusions: Higher levels of exposure to nicotine and some N′-nitrosamines may be observed in MSC, and SMK are exposed to higher levels of combustion-related toxicants. Changes in BioEff consistent with some aspects of inflammation, oxidative stress, and altered lipid metabolism were detected in SMK compared to the non-smoking groups. The biomarker data further improve our understanding of pathophysiological changes and the risk continuum associated with various tobacco products, and could be useful components of future assessments of tobacco products.

Background: The CALIPER program is a national research initiative aimed at closing the gaps in pediatric reference intervals. CALIPER previously reported reference intervals for endocrine and special chemistry markers on Abbott immunoassays. We now report new pediatric reference intervals for immunoassays on the Beckman Coulter Immunoassay Systems and assess platform-specific differences in reference values. Methods: A total of 711 healthy children and adolescents from birth to <19 years of age were recruited from the community. Serum samples were collected for measurement of 29 biomarkers on the Beckman Coulter Immunoassay Systems. Statistically relevant age and/or gender-based partitions were determined, outliers removed, and reference intervals calculated in accordance with Clinical and Laboratory Standards Institute (CLSI) EP28-A3c guidelines. Results: Complex profiles were observed for all 29 analytes, necessitating unique age and/or sex-specific partitions. Overall, changes in analyte concentrations observed over the course of development were similar to trends previously reported, and are consistent with biochemical and physiological changes that occur during childhood. Marked differences were observed for some assays including progesterone, luteinizing hormone and follicle-stimulating hormone where reference intervals were higher than those reported on Abbott immunoassays and parathyroid hormone where intervals were lower. Conclusions: This study highlights the importance of determining reference intervals specific for each analytical platform. The CALIPER Pediatric Reference Interval database will enable accurate diagnosis and laboratory assessment of children monitored by Beckman Coulter Immunoassay Systems in health care institutions worldwide. These reference intervals must however be validated by individual labs for the local pediatric population as recommended by CLSI.

Background : Serum alkaline phosphatase (ALP) plays a critical role in the diagnosis of various diseases, and the establishment of relevant, reliable reference intervals (RI) is key to avoiding misdiagnoses. In 2011, IFCC published the new reference measurement procedure (RMP) for the determination of serum ALP in which one of the main modifications was the measuring temperature of the assay. Here, the new RMP was used to help establish RIs for serum ALP concentrations in healthy Chinese Han. Methods: Volunteer individuals in Guangdong province, China (n=1622) were screened by questionnaire and laboratory testing for eligibility as a reference. Blood (20 mL) was collected and samples were measured by the Roche Modular system using the new RMP for the serum ALP compatible method. Partitioning of values by gender and/or age was evaluated with a standard normal deviate test after removing outliers. A simple non-parametric method for a two-sided 95% distribution of reference values was calculated. Results: Serum ALP concentrations were obtained from the cohort of eligible reference individuals (n=658). The RI for serum ALP in males age 18–79 years was 48–131 U/L. Females were partitioned into two age groups based on statistical analysis, 18–49 years and 50–79 years, and the RIs derived were 40–106 U/L and 57–159 U/L, respectively. Conclusions: RIs for serum ALP for Chinese Han individuals in between the ages of 18 and 79 years were determined and required partitioning due to the higher ALP values of females age 50–79 years.

Background: Recent evidence suggests that red blood cell distribution width (RDW), a simple measure of anisocytosis, may predict the risk of adverse clinical outcomes in both the general population and in patients with severe pathologies. Since it was also shown that the birth season influences the lifetime disease risk, this study was aimed to investigate whether an association may exist between adult RDW values and birth season. Methods: The study population consisted in healthy Caucasian blood donors aged 18 or older, undergoing routine laboratory testing before regular blood donation. Results: Overall, 6122 healthy blood donors were included in this study (median age 41 years; 1807 women and 4315 men). Age, sex, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) but not hemoglobin and hematocrit were found to be independent predictors of RDW. When the study population was classified according to birth season, a significant difference was found for RDW values, but not for age, sex, hemoglobin, hematocrit, MCV and MCH. Subjects born in spring exhibited RDW values generally higher compared to those born in other seasons, reaching statistical significance when compared to those born in summer and winter. In particular, subjects born in spring had a 33% (p=0.014) higher probability of displaying increased RDW values in adulthood compared to those with summer birth. Conclusions: Despite additional studies that are needed to confirm these original findings, the evidence that a significant link exists between birth season and adult anisocytosis provides a plausible explanation for the association between birth season and lifetime disease risk.

Background: New highly sensitive (hs) assays have challenged the interpretation of cardiac troponins (cTn). The present study was designed to evaluate simultaneously conventional cTnT and cTnI together with their corresponding highly sensitive determinations in stable hemodialysis (HD) patients. Ability of cTn to stratify HD patient risk was assessed. Methods: A total of 224 stable HD patients was included in this observational study. cTnT and hs-cTnT were measured using Roche cTnT/hs-cTnT assays based on a Cobas e601 ® analyzer. cTnI and hs-cTnI were measured using Beckman AccuTnI/hs-TnI IUO assays on Access II system. Patients were followed up prospectively during 9 years. Relationship between cTn level and mortality was assessed through Cox survival analysis. Results: The median cTnT and cTnI concentrations were 38.5 ng/L (IQR, 18.8–76) and 10 ng/L (IQR, 10–20), respectively. The median hs-cTnT and hs-cTnI concentrations were 62.5 ng/L (IQR, 38.8–96.3) and 13.9 ng/L (IQR, 8.4–23.6), respectively. The prevalence of values above the 99th percentile was significantly more marked with cTnT (85.3 and 97.8% for conventional and hs cTnT, respectively) than with cTnI (7.6 and 67.4% for conventional and hs cTnI, respectively). During the follow-up, 167 patients died, mainly from cardiac cause (n=77). The optimized cut-off values, determined by bootstrap method, predicting mortality were 38, 69, 20 and 11 ng/L for cTnT, hs-cTnT, cTnI and hs-cTnI, respectively. After full adjustment, elevated plasma concentrations of all troponin were significant predictors of mortality. Conclusions: A large proportion of patients free of acute coronary syndrome (ACS) has hs-cTn I or T higher than the 99th percentile which could be seen as a limiting factor for ACS screening. However, all generation and type of troponin assays could be reliable indicators of prognosis risk in HD patients.

Background : Autoantibodies against β 1 -adrenergic receptors (β 1 AR) that stimulate cardiac cAMP-production play a causal role in the pathogenesis of human heart failure. Patients can be subjected to specific therapies, if the presence of potentially cardio-noxious β 1 AR-autoantibodies is reliably diagnosed. This requires assessment of IgG-interactions with the native β 1 AR because β 1 AR-autoantibodies target a conformational epitope inadequately presented by denatured receptors or linear peptides. Here, we report on a standardised diagnostic procedure for the assessment of β 1 AR-autoantibodies in heart failure patients, which is based on IgG-binding to native human β 1 AR. Methods: Good laboratory practice (GLP)-conform measurement of β 1 AR-autoantibodies was based on flow-cytometric quantification of differential IgG-binding to native HT1080 cells overexpressing biofluorescent human β 1 AR or not. Receptor-specific IgG-binding was derived from IgG-related median fluorescence of β 1 AR-positive cells corrected for background staining of β 1 AR-negative cells admixed to each measurement. The slope of IgG binding at two different concentrations was used as measure for the titre/avidity of β1AR-autoantibodies. Results: Sensitivity and specificity of the novel procedure for high β 1 AR-autoantibody levels in dilated cardiomyopathy patients (n=40, NYHA class III-IV) relative to n=40 matched healthy subjects was >90%. It was similar to functional assays considered the gold standard and vastly superior to existing screening-procedures employing fixed cells or linear receptor-peptides as auto-antigenic targets. Inter-assay scatter was 7%–15% and linear dilution recovery was within ±10% of expected values throughout. Conclusions: The novel assay possibly provides a tool to determine true prevalence and clinical impact of β 1 AR-autoantibodies. Furthermore, it may serve as companion diagnostic for therapies specifically directed at β 1 AR-autoantibodies.

Background: Some changes of glycoproteins have been identified in the serum of patients with different liver diseases, which provided potential glycan biomarkers for diagnosis, prognosis and monitoring of disease progression. Methods: We established a lectin-antibody sandwich ELISA method to detect fucosylated fetuin A (fuc-fetuin A) level in serum, in which biotinylated Aleuria aurantia lectin (AAL) was used for specific recognition. Then serum fuc-fetuin A level was detected in 108 healthy controls and 548 hepatitis B virus (HBV)-infected patients, including 232 hepatocellular carcinoma (HCC) patients, 114 liver cirrhosis (LC) patients, 86 liver fibrosis (LF) patients, and 116 asymptomatic HBV carriers, to assess its diagnostic and prognostic value in HBV-related liver diseases. Results: Serum fetuin A level decreased in LC patients as compared to HCC patients or healthy controls, while it decreased further according to the increasing Child-Pugh grades. The fuc-fetuin A level was in a decreasing order in LC, HCC, LF, HBV-carriers and healthy controls. For distinguishing LC and HCC patients from LF, HBV-carriers and healthy controls, the area under the receiver operating characteristic (ROC) curve is 0.871, with a sensitivity of 0.818 and specificity of 0.819. The survival analysis revealed that higher fuc-fetuin A level was significantly associated with worse recurrence-free survival in HCC patients (p=0.018). Conclusions: The results indicated that the serum fuc-fetuin A might serve as a potential glycan biomarker for distinguishing LC and HCC from LF, HBV-carriers and healthy controls. Furthermore, the preoperative fuc-fetuin A level could be a useful prognostic biomarker for HCC patients.