Volume 48, Issue 12

Statins are one of the most important medications in cardio-vascular diseases since they block cholesterol synthesis by inhibiting the 3-hydroxy-3-methylglutaryl coenzyme A reductase and thus reduce low density lipoprotein concentrations. In the last years, numerous pleiotropic properties of statins have been described, beyond their well-known lipid lowering function. In particular, they are able to modulate inflammation, which plays a pivotal role in the atherosclerotic process. Several trials have shown a direct correlation between statin therapy and lower C-reactive protein concentrations. Moreover, a large body of pathophysiological studies has demonstrated that statins lower cytokine concentrations and inhibit recruitment, migration and cell adhesion to endothelium by attenuating chemokine production. They also inhibit inflammatory pathways regulated by proteins as Ras and Rho, and increase nitric oxide production which exerts a protective effect on endothelium. In addition to reducing inflammation in coronary atherosclerosis, statins also have beneficial effects in chronic inflammatory and autoimmune diseases, such as psoriasis, and they could induce clinical improvement. Statins seem to exert benefits even in settings of infection. These results suggest that initiating and monitoring statin therapy on the basis of inflammatory markers, in particular C-reactive protein, may improve cardiovascular prevention and treatment. Clin Chem Lab Med 2010;48:1685–91.

The plasma concentration of C-reactive protein (CRP), the first acute-phase protein to be identified, increases dramatically following tissue injury or inflammation. Although the physiological role of CRP is still not fully known, it has been suggested that concentrations might increase as part of the acute-phase response for facilitating non-specific immune functions, defense against bacterial pathogens, clearance of apoptotic and necrotic cells to prevent immunization against autoantigens and acceleration of the repair process. In agreement with the evidence that inflammation plays a pivotal role in the pathogenesis of atherosclerosis, CRP concentrations have been associated with cardiovascular disease, and measurement of CRP has therefore been proposed as a valuable aid to predict and stratify the risk of myocardial infarction and stroke. Recently, some clinical and biological evidence in support of the hypothesis that CRP might be also involved in the onset of venous thrombosis have emerged. Native and monomeric CRP exert several prothrombotic activities, including activation of blood coagulation, impairment of the endogenous fibrinolytic capacity, and stimulation or enhancement of platelet adhesiveness and responsiveness. Epidemiological investigations have also shown that CRP concentrations are associated with increased risk of venous thromboembolism and, even more interestingly, that statins might be effective in reducing the risk of this pathology. Although there is increasing emphasis that CRP might not only be a marker but also an active player in the development of venous thrombosis, further evidence is needed to establish which event comes first – thrombosis or inflammation. Clin Chem Lab Med 2010;48:1693–701.

The discovery and development of new biomarkers continues to be an exciting and promising field. Improvement in prediction of risk of developing disease is one of the key motivations in these pursuits. Appropriate statistical measures are necessary for drawing meaningful conclusions about the clinical usefulness of these new markers. In this review, we present several novel metrics proposed to serve this purpose. We use reclassification tables constructed on the basis of clinically meaningful disease risk categories to discuss the concepts of calibration, risk separation, risk discrimination, and risk classification accuracy. We discuss the notion that the net reclassification improvement (NRI) is a simple yet informative way to summarize information contained in risk reclassification tables. In the absence of meaningful risk categories, we suggest a ‘category-less’ version of the NRI and integrated discrimination improvement as metrics to summarize the incremental value of new biomarkers. We also suggest that predictiveness curves be preferred to receiver operating characteristic curves as visual descriptors of a statistical model's ability to separate predicted probabilities of disease events. Reporting of standard metrics, including measures of relative risk and the c statistic, is still recommended. These concepts are illustrated with a risk prediction example using data from the Framingham Heart Study. Clin Chem Lab Med 2010;48:1703–11.

Background: The detection and diagnosis of β-thalassaemia for populations with molecular heterogeneity, or diverse ethnic groups, has increased the need for the development of an array high-throughput diagnostic tool that can deliver large scale genetic detection. We report on the update and validation of the ThalassoChip, a β-thalassaemia genetic diagnostic tool which is based on arrayed primer extension (APEX) technology. Methods: ThalassoChip slides with new and redesigned probes were prepared for testing the microarray. Six hundred and sixty DNA samples collected from eight Mediterranean countries were used for standardisation, optimisation and validation of the ThalassoChip. The β-globin gene region was amplified by PCR, the products were hybridised to the probes after fragmentation and the APEX reaction followed. Results: The ThalassoChip was updated with new probes and now has the ability to detect 57 β-globin gene mutations and three single nucleotide polymorphisms (SNPs) in a single test. The ThalassoChip as well as the PCR and APEX reactions were standardised and optimised using 500 DNA samples that were previously genotyped using conventional diagnostic techniques. Some probes were redesigned in order to improve the specificity and sensitivity of the test. Validation of the ThalassoChip performed using 160 samples analysed in blinded fashion showed no error. Conclusions: The updated version of the ThalassoChip is versatile, robust, cost-effective and easily adaptable, but most notably can provide comprehensive genetic diagnosis for β-thalassaemia and other haemoglobinopathies. Clin Chem Lab Med 2010;48:1713–8.

Background: The aim of this study was to compare the use of glycated hemoglobin (HbA 1c ) and the oral glucose tolerance test (OGTT) in the diagnosis of impaired glucose tolerance in high-risk individuals. Methods: A total of 713 patients with at least two risk factors for the development of type 2 diabetes were enrolled in the study. Fasting glucose and HbA 1c were measured in all individuals. Patients whose fasting glucose concentrations were below 7.0 mmol/L underwent an OGTT. Results: From the 713 patients, 234 were euglycemic, 200 had impaired fasting glucose, 118 presented with impaired glucose tolerance and 161 met the diagnostic criteria for type 2 diabetes. OGTT was performed in a total of 596 patients (83.6%). Statistically significant differences were observed for HbA 1c concentrations in all groups. Receiver operating characteristic curve analysis was performed to assess the capability of HbA 1c to discriminate between normal glucose tolerance and impaired glucose tolerance. An HbA 1c value of 36 mmol/mol (5.4%) gave an optimal sensitivity of 85% and a specificity of 73%, and a negative predictive value of 97% for identifying patients with impaired glucose tolerance. Conclusions: HbA 1c can be used to rule outpatients at high-risk of developing type 2 diabetes. Clin Chem Lab Med 2010;48:1719–22.

Background: Posaconazole is a novel antifungal drug for oral application intended especially for therapy of invasive mycoses. Due to variable gastrointestinal absorption, adverse side effects, and suspected drug-drug interactions, therapeutic drug monitoring (TDM) of posaconazole is recommended. Method: A fast ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for quantification of posaconazole with a run-time <3 min was developed and compared to a LC-MS/MS method and HPLC method with fluorescence detection. Results: During evaluation of UPLC-MS/MS, two earlier eluting peaks were observed in the MRM trace of posaconazole. This was only seen in patient samples, but not in spiked calibrator samples. Comparison with LC-MS/MS disclosed a significant bias with higher concentrations measured by LC-MS/MS, while UPLC-MS/MS showed excellent agreement with the commercially available HPLC method. In the LC-MS/MS procedure, comparably wide and left side shifted peaks were noticed. This could be ascribed to in-source fragmentation of conjugate metabolites during electrospray ionisation. Precursor and product ion scans confirmed the assumption that the additional compounds are posaconazole glucuronides. Reducing the cone voltage led to disappearance of the glucuronide peaks. Slight modification of the LC-MS/MS method enabled separation of the main interference, leading to significantly reduced deviation. Conclusions: These results highlight the necessity to reliably eliminate interference from labile drug metabolites for correct TDM results, either by sufficient separation or selective MS conditions. The presented UPLC-MS/MS method provides a reliable and fast assay for TDM of posaconazole. Clin Chem Lab Med 2010;48:1723–31.

Background : The goal of this study was to evaluate plasma D-dimer as a diagnostic marker for exclusion of suspected aortic dissection (AD). Methods : Two-hundred and sixty suspected AD patients were enrolled, including acute AD, n=107; chronic AD, n=17; acute myocardial infarction (AMI), n=70; pulmonary embolism (PE), n=18; non-ST elevation myocardial infarction (NSTEMI), n=28; and unstable angina (UA), n=20. All patients had D-dimer testing performed (Roche Diagnostics GmbH) immediately following admission. Results: The D-dimer concentrations in both the acute AD group [median: 3.47; 95% confidence interval (CI): 2.43–4.50 μg/mL] and chronic AD group (median: 1.09; 95% CI: 0.36–3.81 μg/mL) were significantly higher than those in patients in the AMI, NSTEMI and UA groups (p=0.000), but not when compared to the PE group. One (0.8%) patient was identified in the acute AD group who presented with a low D-dimer value (0.04 μg/mL), indicating the existence of intramural hematoma as demonstrated by CT. Conclusions: D-dimer may be used as a potential marker for suspected AD, with high sensitivity of up to 99.2% (1/124). Regardless of the cut-off threshold selected, the sensitivity of D-dimer was unable to reach 100%. Further examinations, including imaging technology, were necessary to diagnose the suspected AD patients who had negative D-dimer result. Clin Chem Lab Med 2010;48:1733–7.

Background: Accurate determination of factor XIII (FXIII) activity is crucial for replacement therapy. FXIII activity is typically determined using a coupled enzymatic reaction that measures nicotinamide adenine dinucleotide hydride (NADH) consumption at 340 nm. Methods: Here, we describe the development of a prototype for a novel FXIII activity assay for detection at 405 nm by replacing NADH with thio-NADH, and the application of FXIII immuno-depleted plasma as a diluent for calibration. Results: Performance data show up to two-fold lower susceptibility of the prototype assay to interferences from hemolyzed, icteric, and lipemic samples when compared to a NADH assay format. In addition, the use of FXIII immuno-depleted plasma as diluent for calibration improved recovery almost two-fold in the lower measurement range. The novel prototype assay correlates well with a conventional assay (r=0.98, y=0.99·x+2.17% FXIII, n=173). Conclusions: The described prototype assay has the potential to (a) increase trueness of measurement of low levels of FXIII, (b) improve robustness due to reduction from interferences, and (c) can be used on a broad range of coagulation instruments due to its detection at 405 nm. Clin Chem Lab Med 2010;48:1739–43.

Background: The Marburg I (MRI) single nucleotide poly-morphism (SNP) of the factor VII-activating protease ( FSAP ) gene has been associated with thrombophilia, thromboembolism, atherosclerosis, and the incidence and progression of carotid stenosis. At present, MRI SNP testing is mainly performed using costly nucleic acid analysis. The ratio between FSAP activity and antigen concentrations in citrated plasma has been used to assess the FSAP genotype. Methods: This article describes the development of a prototype ELISA for the detection of the MRI FSAP alloenzyme, and its correlation to FSAP genotypes to assess whether a positive MRI FSAP ELISA result may be used as a surrogate marker for the presence of the MRI SNP. Results: ELISA results were correlated with FSAP genotypes from 523 blood donors measured using PCR. Diagnostic sensitivity and specificity of the assay for determina-tion of the genotype were 100% (95% confidence interval [CI]: 93.36–100) and 99.79% (95% CI: 98.80–99.96), respectively. Maximum run-to-run, within-run, and total coefficients of variation were 7.8%, 7.9%, and 9.9%, respectively. No cross-reactivities with homologues of the MRI FSAP alloenzyme were observed. Test performance was not affected by typical interfering compounds. Conclusions: The data demonstrate that an immunoassay applying antibodies specific to the MRI FSAP alloenzyme can provide sufficiently accurate detection of the MRI SNP. This will significantly simplify MRI FSAP testing, particularly in large cohorts. Clin Chem Lab Med 2010;48:1745–9.

Background: In cystic fibrosis (CF), changes in fatty acid (FA) composition of serum phospholipids (PL) and cell membranes can account, in part, for the inflammatory state of the disease. The severity of the genotype is known to correlate with the degree of FA changes. Liver diseases, such as cholestasis and cirrhosis are also known to influence FA status. Until now, there is no data on the influence of CF related liver disease (CFRLD) on the FA status of CF patients. The aim of this study was to evaluate, whether the presence of CFRLD influences FA status. Methods: A fasting blood sample for the determination of serum vitamin E and PL-FA composition was collected from 79 CF patients with stable pulmonary disease and under good control in our CF centre. Patients with CFRLD (n=13) were compared to CF patients with the same severity of genotype (n=66) but without CFRLD. Results: The CF patients with CFRLD had lower docosahexaenoic acid (DHA, 22:6n-3) and increased docosatetraenoic acid (22:4n-6). There were no significant differences in the precursors of these FAs. Conclusions: DHA concentration in patients with CFRLD is decreased more substantially compared with their genotype controls. The presence of CFRLD should be taken into account in future FA studies in CF patients. Clin Chem Lab Med 2010;48:1751–5.

Background: During the last decade, the contribution of omega-3 and -6 long chain-polyunsaturated fatty acids (LC-PUFA) and conjugated linoleic acids (CLA) to the prevention and development of many inflammatory and cardiovascular diseases has been of growing interest. In order to investigate the etiology of these diseases, rapid, combined and comparable methods are invaluable for monitoring both the intake and the incorporation of these fatty acids (FA). Methods: The fatty acid methyl esters (FAME) were analyzed using a gas chromatography/flame ionization detector (GC-FID) system and quantified with an internal standard (C18:0 iso). Results: An effective and rapid protocol for sample preparation and the analysis of FAME was developed and validated. The comparison of different extraction methods showed that the Hara and Radin method gave the best results for serum and erythrocyte membranes. Excellent mean within-day and day-to-day precisions for serum, erythrocytes and cow's milk LC-PUFAs demonstrated the high reproduci-bility of the method. Recovery rates for FAMEs in serum and milk were close to 100%. In addition, high mean method linearity (R 2 ) (>0.99) was shown for serum, erythrocytes and cow's milk. The sensitivity for FA achieved by GC analysis was acceptable. Conclusion: With the newly adapted protocols, combined and rapid analyses of up to 46 FAMEs, including CLAs and omega-3/-6 LC-PUFAs, can be conducted with high reliability and reproducibility using serum, erythrocyte membranes or cow's milk. This provides a novel tool that can be easily implemented in epidemiological studies or clinical diagnostics. Clin Chem Lab Med 2010;48:1757–63.

Background: Automation and standardization of sediment analysis of urine samples by flow cytometry might serve as an alternative to labor-intensive laboratory methods, such as microscopic examination and culture. The Sysmex UF-1000i is a urine flow cytometer that uses two separate channels for counting blood cells and bacteria. Methods: In this study, 358 urine samples were analyzed with the Sysmex UF-1000i in parallel with manual microscopy, Gram stain and bacterial culture, the latter considered the gold standard. Results: Reproducibility for detection of white and red blood cells and bacteria was good, while detection of yeast proved unreliable. Depending on the definition of urinary tract in-fection (UTI) used, the negative predictive value and the per-centage of false-negative results were 100% and 0% [UTI ≥ 10 5 colony forming units (CFU)/mL] and 99% and 1.3%, (UTI ≥10 4  CFU/mL), respectively. Pre-screening with the Sysmex UF-1000i would have resulted in a reduction of bacterial culture by 42%. Carry over of bacteria between consecutive samples due to the use of fixed sample needle was observed, but did not result in false-positive interpretation of Sysmex UF-1000i results. Because of the occurrence of carry over, samples that have been analyzed with the Sysmex UF-1000i cannot be used for subsequent urine culture. Conclusions: In conclusion, the Sysmex UF-1000i offers the possibility for screening high numbers of urine samples in a fast and standardized way, resulting in a reduction in workload and speeding the diagnostic process. It is not recommended for use in complicated patient populations, such as neutropenic patients and patients in whom yeast infection is suspected. Clin Chem Lab Med 2010;48:1765–71.

Background: Cardiometabolic disorders including cardiovascular disease (CVD) where the relevance of regular coffee consumption is debatable, has been linked with the development of chronic kidney disease (CKD). A more recent study suggests that coffee consumption is associated with normal or increased kidney function as assessed by the estimated glomerular filtration rate (eGFR). The present study investigated whether the association between coffee and the eGFR was independent of chronic inflammation, and whether adding sugar to coffee could affect the eGFR. Methods: A total of 114 age- and gender-matched Japanese individuals (females/males=68/46, mean age=59.5 years), without CVD and severe CKD, were studied. Clinical variables, such as body mass index, blood pressure, blood glucose, lipids and high-sensitivity C-reactive protein (hsCRP), in addition to eGFR [the Modification of Diet in Renal Disease (MDRD) study equation], were measured. Results: Coffee drinkers had higher eGFR values [73.9±16.5 (SD) mL/min/1.73 m 2 ] than non-coffee drinkers (68.6±11.7). The difference remained significant (F=5.04, p=0.027), independently of clinical variables, including hsCRP. The eGFR values among coffee drinkers were similar between the subjects with and without use of sugar. Conclusions: The association of coffee drinking habits to eGFR may occur independently of inflammation as assessed by hsCRP. The use of sugar may have no effect on GFR. Further research is needed to clarify this phenomenon. Clin Chem Lab Med 2010;48:1773–6.

Background: Lactic acid concentrations (LA) are an established marker of bacterial infection in cerebrospinal fluid (CSF). However, use of LA for the detection of infection in CSF with residual blood has not been fully evaluated. Methods: Analysis of LA and total protein, cell count and bacterial culture were performed in 90 lumbar and ventricular CSF samples contaminated with blood. Results: Bacterial culture was positive in six CSF samples. The diagnostic value of the cell count was significantly higher than that of LA for the prediction of a positive culture, even if all culture positive and all likely infected samples were included in the analysis. There was no significant difference in LA concentrations between positive or likely positive ventricular CSF samples and all negative, ventricular samples. Conclusions: Although LA concentrations in CSF are evidently a predictor of bacterial infection, its diagnostic value for the detection of bacterial infection in ventricular CSF with residual blood is limited. Clin Chem Lab Med 2010;48:1777–80.

Background: The Precision ® (Abbott Diabetes Care) point-of-care biosensor test strips are widely used by patients with diabetes and clinical laboratories for measurement of plasma β-hydroxybutyrate (β-HB) concentrations in capillary blood samples obtained by fingerstick. In the literature, this procedure has been validated only against the enzymatic determination of β-HB in venous plasma, i.e., the method to which the Precision ® has been calibrated. Methods: In this study, the Precision ® Xceed was compared to a methodologically different and superior procedure: determination of β-HB by liquid chromatography tandem-mass spectrometry (LC-MS/MS) in capillary blood spots. Blood spots were obtained from the same fingerstick sample from out of which Precision ® measurements were performed. Linearity was tested by adding varying amounts of standard to an EDTA venous whole blood matrix. Results: The Precision ® was in good agreement with LC-MS/MS within the measuring range of 0.0–6.0 mmol/L (Passing and Bablok regression: slope=1.20 and no significant intercept, R=0.97, n=59). Surprisingly, the Precision ® showed non-linearity and full saturation at concentrations above 6.0 mmol/L, which were confirmed by a standard addition experiment. Results obtained at the saturation level varied between 3.0 and 6.5 mmol/L. Conclusions: The Precision ® β-HB test strips demonstrate good comparison with LC-MS/MS. Inter-individual variation around the saturation level, however, is large. Therefore, we advise reporting readings above 3.0 as >3.0 mmol/L. The test is valid for use in the clinically relevant range of 0.0–3.0 mmol/L. Clin Chem Lab Med 2010;48:1781–4.

Background: Histone deacetylases (HDACs) have been reported to be poor prognostic indicators in patients with cancer. However, no data are available for the role of single nucleotide polymorphism (SNP) of class I HDAC in hepato-cellular carcinoma (HCC). Therefore, we investigated the association of class I HDAC isoforms genomic polymorphisms with risk of HCC and tumor recurrence following liver transplantation (LT). Methods: One hundred and ninety-six Chinese subjects consisting of 97 HCC patients and 99 controls were enrolled in this study. Nine polymorphisms of the HDAC1, HDAC2 , and HDAC3 gene (rs2530223, rs1741981, rs2547547, rs13204445, rs6568819, rs10499080, rs11741808, rs2475631, rs11391) were examined using Applied Biosystems SNaP-Shot and TaqMan technology. Results: We found no significant difference in genotype frequencies between the HCC cases and controls. In terms of tumor recurrence following LT, patients carrying the T allele of HDAC1 SNP rs1741981 showed a favorable outcome for recurrence free survival when compared with patients homozygous for CC. In addition, the same significant trend was observed in HDAC3 SNP rs2547547. Kaplan-Meier analysis showed that the combination of the T variant allele (CT+TT) of HDAC1 SNP rs1741981 and the homozygous TT variant allele of HDAC3 SNP rs2547547 was the most favorable prognostic factor. The risk for postoperative tumor recurrence was about 2.2-fold lower for patients with this genotype combination compared with carriers of the HDAC1 SNP rs1741981 CC and HDAC3 SNP rs2547547 CT genotype combination (hazard ratio: 2.235, p=0.003). Conclusions: Our data suggest that combined analysis of HDAC1 SNP rs1741981 and HDAC3 SNP rs2547547 may be a potential genetic marker for HCC recurrence in LT patients. Clin Chem Lab Med 2010;48:1785–91.

Background: The most frequently used methods for meas-uring global DNA methylation are based on two different principles: the use of methylation-sensitive restriction endonucleases followed by analysis of the obtained fragments, or the hydrolysis of genomic DNA followed by specific detection and quantification of the 5-methylcytosine content. We aimed to compare two different methods for evaluation of global DNA methylation: the cytosine extension assay after enzymatic digestion of DNA (Cyt-Ext), and a recently described method using liquid chromatography-electrospray ionization-tandem mass spectrometry after DNA hydrolysis (LC-MS/MS). Methods: Both approaches were applied to evaluate global DNA methylation in leukocyte DNA from 96 healthy subjects. Calf thymus and pBR322 DNAs were used as hyper- and hypo-methylated references, respectively. Results: Using the Cyt-Ext method, the DNA from healthy individuals showed radiolabel incorporation of 11,312± 1600 Dpm/μg DNA, while the LC-MS/MS method showed 4.55±0.1% methylation. Results are shown as mean±SD. The analysis of hypo- and hyper-methylated references showed that both methods are practical for discriminating different levels of methylation. Conclusions: Cyt-Ext and LC-MS/MS are viable methods in evaluating global DNA methylation status. However, the LC-MS/MS assay allows absolute quantification and displays far superior intra-day precision. Therefore, we consider the later approach to be better for use in global DNA methylation studies. Clin Chem Lab Med 2010;48:1793–8.

Background: Knowledge of biological variation (BV) is important for determining analytical goals and for establishing the magnitude of change between two consecutive measurements which indicate change in a patients' health status. The aim of this work is to determine the BV for total choriogonadotropin (β chain) (β-hCG) and α-fetoprotein (AFP) in patients diagnosed with testicular cancer but with no evidence of recurrence of disease. Methods: We estimated BV from a mean of five consecutive measurements in 28 patients diagnosed with testicular cancer, 3 months after tumor resection or 4 months after complete treatment with chemotherapy. The mean sampling interval was 3 months. Results: The mean concentrations of α-fetoprotein and choriogonadotropin (β chain) were 3.9 μg/L and 0.79 IU/L, respectively. Between-run analytical variation was 7.1% at 4.1 μg/L for α-fetoprotein, and 19% at 0.65 IU/L for choriogonadotropin (β chain). BV obtained for α-fetoprotein and choriogonadotropin (β chain) was 12.4% and 16.7%, respectively, and the reference change value (RCV) for one-tail showed 38.2% and 60.7% for α-fetoprotein and choriogonadotropin (β chain), respectively. Conclusions: The estimation of BV allows us to calculate analytical goals and RCVs, necessary tools for the correct interpretation of serial measurements in the follow-up of patients. Clin Chem Lab Med 2010;48:1799–801.

Background: Certain genetic polymorphisms can lead to differences in immunity function, resulting in different clinical outcomes for hepatitis B virus (HBV) patients. The aim of this study was to investigate the association between apolipoprotein E ( ApoE ) gene polymorphisms and HBV infection status in northern Chinese individuals. Methods: Genomic DNA was extracted using an improved sodium iodide (NaI) method from the peripheral blood of 270 patients with hepatitis B and 112 healthy controls. Multiplex Amplification Refractory Mutation System (Multi-ARMS) was performed to analyze ApoE gene poly-morphisms with three alleles ( ɛ2 , ɛ3 , ɛ4 ) in patients and controls. A chemiluminescence assay was used to detect serological markers for hepatitis B infection status. Results: An improved PCR system for the detection of ApoE gene polymorphisms was established successfully. The frequency of the ɛ2 allele in patients with HBV infection was higher than that of normal controls (p<0.05). The ɛ2 allele, compared with the ɛ3 and ɛ4 alleles, showed positive correlation with the different HBV infection models [odds ratio (OR)=1.735, 95% confidence interval (CI): 1.509–1.999, p<0.01; OR=1.768, 95% CI: 1.554–2.011, p<0.01]. The OR for the ApoE ɛ2 allele was 1.503 in a multivariate unconditional logistic regression model (OR=1.503, 95% CI: 1.212–1.754, p<0.01). Conclusions: Our results indicated that the ApoE gene poly-morphism was associated with HBV infection, and the ɛ2 allele showed positive correlation with HBV infection in northern China. Clin Chem Lab Med 2010;48:1803–7.

Background: Helicobacter pylori ( H. pylori ) infection has been associated with iron deficiency anemia. However, results reported in the literature are contradictory. The goal of the present study was to study the possible association between H. pylori infection and iron deficiency in a sample of adults. Methods: One hundred and fifty individuals were studied ( H. pylori -positive n=75; H. pylori -negative n=50). The presence of anemia was determined using red cell indices and reticulocyte hemoglobin content (CHr). Iron status was assessed based on serum iron and ferritin levels. Possible involvement of inflammatory activity in erythropoiesis was investigated by measuring the correlation between C-reactive protein (CRP) and red cell indices and iron status. Results: There were no significant differences in the hematological or biochemical parameters for the two groups. Iron deficiency was diagnosed in six individuals, but no difference in prevalence was found between the H. pylori -positive and H. pylori -negative groups. A weak but significant inverse correlation was observed between CRP and CHr concentrations and between serum gastrin and CHr in the H. pylori -positive group. These results suggest a reduction in iron availability for reticulocyte hemoglobinization, but insufficient to cause anemia. Conclusions: H. pylori infection was not a determining factor for development of iron deficiency in our study population. Clin Chem Lab Med 2010;48:1809–12.

Background: Septic shock is a major health care problem that affects a heterogeneous population of patients. To improve sepsis management, a key point is to decrease this heterogeneity by stratifying patients according to specific criteria, such as appropriate biomarkers. As the early phase of septic shock is characterized by cardiovascular dysfunction, precursors of vasoactive hormones represent interesting candidates. The objective of the present study was to concomitantly assess the predictive value of C-terminal proendothelin-1 and midregional proatrial natriuretic peptide (CT-proET-1 and MR-proANP, respectively vasoconstrictor and vasodilator) on 28-day mortality following septic shock. Methods: In this observational study which included 99 patients, concentrations of MR-proANP and CT-proET-1 were measured using an immunoluminometric assay three times within the first week after the onset of septic shock. Results: While MR-proANP concentrations were significantly increased in non-survivors in comparison with survivors, no differences were noted for CT-proET-1. Increased MR-proANP concentrations were significantly associated with mortality after both univariate and multivariate analyses, adjusted for usual clinical confounders [SAPS II (simplified acute physiology score II), SOFA (sepsis-related organ failure assessment) scores and number of co-morbidities]. Conclusions: In septic shock patients, MR-proANP appears to be a good predictor of 28-day mortality, whereas CT-proET-1 does not present any predictive value during monitoring. Clin Chem Lab Med 2010;48:1813–20.

Background: Cardiac extra-cellular matrix (ECM) fibrosis plays an important role in the pathophysiology of heart failure (HF). It may provide electrical heterogeneity and a substrate for arrhythmogenicity, which may cause sudden cardiac death (SCD). Methods: Twenty-one patients with manifestations of HF and a left ventricular ejection fraction (LVEF) ≤50% were enrolled. The median age was 62 years and median LVEF was 33%. Time- and frequency-domain analysis of heart rate variability (HRV) on 24 h ambulatory electrocardiography recording was assessed. Serum markers of ECM turnover including type I and III aminoterminal propeptide of procollagen (PINP and PIIINP), matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) were analyzed. Results: The serum PIIINP concentration was correlated significantly with standard deviation of all normal to normal R-R intervals (SDNN) (r=–0.722, p=<0.001), percentage of adjacent NN interval differences >50 ms (pNN50) (r=–0.528, p=0.014), percentage of adjacent NN interval differences >20 ms (pNN20) (r=–0.545, p=0.002), very low frequency (VLF) (r=–0.490, p=0.024), low frequency (LF) (r=–0.491, p=0.024), and high frequency (HF) (r=–0.513, p=0.018). PINP, MMP-2, -9, TIMP-1 were not correlated with time- and frequency-domain analysis of HRV. Conclusions: PIIINP was significantly correlated with time- and frequency-domain analysis of HRV in HF patients. PIIINP is a potential serological marker to evaluate cardiac autonomic control and risk of SCD in HF patients. Clin Chem Lab Med 2010;48:1821–7.

Background: It has been observed that hepatic steatosis is related to an increased risk of cardiovascular disease (CVD). Alanine aminotransferase (ALT), an indicator of the severity of hepatic steatosis is also associated with CVD. This study focused on the relationship between hepatic steatosis and ALT with coronary calcification. Methods: We performed a cross-sectional study to examine the association between hepatic steatosis and serum ALT with coronary calcification in 1218 subjects (772 men, 446 women; ages 30–75 years). We evaluated hepatic steatosis and ALT as categorical variables, and constructed four groups (reference group; only with hepatic steatosis; only with ALT >30 U/L; with both hepatic steatosis and ALT >30 U/L), which did not overlap. Multi-detected row computed tomography (MDCT) was used to measure coronary calcium score. Results: The adjusted ORs (95% CIs) for coronary calcification in the four groups were 1.00 (reference), 1.24 (0.68–2.26), 1.82 (0.78–4.23), and 2.12 (1.08–4.20) after adjusting for confounding variables. In addition, an increase in serum ALT activity of 10 U/L was associated with an increased risk of coronary atherosclerosis. Conclusions: In summary, patients with both hepatic steatosis and increases in ALT are associated with coronary calcification as a marker of coronary atherosclerosis determined by MDCT. This finding suggested that subjects with both hepatic steatosis and increased ALT should be considered for further evaluation of coronary atherosclerosis. Clin Chem Lab Med 2010;48:1829–34.