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Background Low-grade immune activation in the gut is a potential treatment target in irritable bowel syndrome (IBS). Aims To determine improvement in IBS symptoms after mesalazine treatment, and the utility of measures of immune activity in the rectal mucosa Methods This was a randomised, double-blind, placebo-controlled, parallel-arm, multicentre trial in subjects with IBS (Rome III criteria), with an eight-week treatment period of mesalazine 2400 mg or plcebo once-daily. The primary endpoint was the global assessment of satisfactory relief of IBS symptoms in ≥50% of weeks during intervention. IBS symptoms were also measured with the IBS severity scoring system; immune activity was measured by mucosal patch technology. A post hoc meta-analysis of randomised placebo-controlled trials of mesalazine in IBS was added. Results Of 181 included patients, 91 received mesalazine and 90 received placebo. The primary endpoint was met by 32 (36%) patients after mesalazine and 27 (30%) after placebo (p = 0.40). There were no differences in response rates related to IBS subtype or post-infection symptom onset. More reduction of abdominal bloating was noted in the mesalazine group (p = 0.02). The meta-analysis showed no effect of mesalazine on IBS symptoms. No mucosal patch technology measure could predict response to mesalazine, and found no differences in the effects of intervention on levels of immune markers. Conclusions Mesalazine is ineffective in reducing IBS symptoms. Rectal measures of immune activity by the mucosal patch technology cannot predict a higher chance of response to mesalazine. publishedVersion

Background The inflammatory process in juvenile idiopathic arthritis (JIA) involves both the innate and the adaptive immune system. The turnover and activity of neutrophil granulocytes may be reflected by proteins secreted from primary or secondary granules and from the cytoplasm of sequestered cells. Our primary aim was to compare the levels of the secondary neutrophil granule protein human neutrophil lipocalin (HNL), in JIA patients and controls, and to explore a possible priming of neutrophils through parallel analyses in plasma and serum. A secondary aim was to relate the levels of HNL to two other well-studied leukocyte proteins, S100A8/A9 and myeloperoxidase (MPO), as well as to clinical aspects of JIA. Methods The concentrations of the three biomarkers in serum, two of them also in plasma, were measured using enzyme-linked immunosorbent assay in 37 children with JIA without medical treatment, in high disease activity based on juvenile arthritis disease activity score 27 (JADAS27), 32 children on medical treatment, mainly in lower disease activity, and 16 healthy children. We assessed for differences between two groups using the Mann-Whitney U test, and used the Kruskal-Wallis test for multiple group comparisons. Spearman rank correlation, linear and multiple regression analyses were used for evaluation of associations between biomarker concentrations and clinical scores. Results The concentrations of HNL and MPO in serum were significantly increased in children with JIA (p p = 0.002) compared with healthy children, but we found no difference in the plasma levels of HNL and MPO between children with JIA and controls. The serum concentrations of MPO and HNL were unaffected by medical treatment, but S100A8/A9 was reduced by medical treatment and correlated with JADAS27 in both univariate (r = 0.58, p Conclusions Neutrophil granulocytes in children with JIA are primed to release primary and secondary granule proteins, without relation to medical treatment, whereas signs of increased turnover and sequestration of neutrophil granulocytes are reduced by treatment. Levels of neutrophil-originating proteins in serum most likely reflect underlying disease activities of JIA.

OBJECTIVES The aim of this study was to investigate airway responsiveness and eosinophil and neutrophil inflammatory markers in clinically confirmed nonasthmatic adolescents with elevated fractional exhaled nitric oxide (FeNO), a marker of type-2 inflammation in the airways. METHODOLOGY A total of 959 subjects from a general population, aged 12 to 15 years, answered a standardised questionnaire and underwent FeNO measurements at a screening visit at school. Adolescents without asthma, who had elevated FeNO (FeNO100 > 15 ppb) (n = 19), and control subjects, with low FeNO (FeNO100

Neutrophils have been suggested mediators of organ dysfunction in COVID-19. The current study investigated if systemic neutrophil activity, estimated by human neutrophil lipocalin (HNL) concentration in peripheral blood, is associated with acute kidney injury (AKI) development. A total of 103 adult patients admitted to intensive care, with PCR-confirmed SARS -CoV-2 infection, were prospectively included (Clinical Trials ID: NCT04316884). HNL was analyzed in plasma (P-HNL Dimer) and in whole blood (B-HNL). The latter after ex vivo activation with N-formyl-methionine-leucine-phenylalanine. All patients developed respiratory dysfunction and 62 (60%) were treated with invasive ventilation. Sixty-seven patients (65%) developed AKI, 18 (17%) progressed to AKI stage 3, and 14 (14%) were treated with continuous renal replacement therapy (CRRT). P-HNL Dimer was higher in patients with invasive ventilation, vasopressors, AKI, AKI stage 3, dialysis, and 30-day mortality (p &lt, 0.001–0.046). B-HNL performed similarly with the exception of mild AKI and mortality (p &lt, 0.001–0.004). The cohort was dichotomized by ROC estimated cutoff concentrations of 13.2 µg/L and 190 µg/L for P-HNL Dimer and B-HNL respectively. Increased cumulative risks for AKI, AKI stage 3, and death were observed if above the P-HNL cutoff and for AKI stage 3 if above the B-HNL cutoff. The relative risk of developing AKI stage 3 was nine and 39 times greater if above the cutoffs in plasma and whole blood, respectively, for CRRT eight times greater for both. In conclusion, systemically elevated neutrophil lipocalin, interpreted as increased neutrophil activity, was shown to be associated with an increased risk of severe AKI, renal replacement therapy, and mortality in COVID-19 patients with respiratory failure.

Chronic obstructive pulmonary disease (COPD) is a destructive inflammatory disease and the genes expressed within the lung are crucial to its pathophysiology. We have determined the RNAseq transcriptome of bronchial brush cells from 312 stringently defined ex-smoker patients. Compared to healthy controls there were for males 40 differentially expressed genes (DEGs) and 73 DEGs for females with only 26 genes shared. The gene ontology (GO) term "response to bacterium" was shared, with several different DEGs contributing in males and females. Strongly upregulated genes TCN1 and CYP1B1 were unique to males and females, respectively. For male emphysema (E)-dominant and airway disease (A)-dominant COPD (defined by computed tomography) the term "response to stress" was found for both sub-phenotypes, but this included distinct up-regulated genes for the E-sub-phenotype (neutrophil-related CSF3R, CXCL1, MNDA) and for the A-sub-phenotype (macrophage-related KLF4, F3, CD36). In E-dominant disease, a cluster of mitochondria-encoded (MT) genes forms a signature, able to identify patients with emphysema features in a confirmation cohort. The MT-CO2 gene is upregulated transcriptionally in bronchial epithelial cells with the copy number essentially unchanged. Both MT-CO2 and the neutrophil chemoattractant CXCL1 are induced by reactive oxygen in bronchial epithelial cells. Of the female DEGs unique for E- and A-dominant COPD, 88% were detected in females only. In E-dominant disease we found a pronounced expression of mast cell-associated DEGs TPSB2, TPSAB1 and CPA3. The differential genes discovered in this study point towards involvement of different types of leukocytes in the E- and A-dominant COPD sub-phenotypes in males and females. This work was supported by the European Union, FP7 project # 200506. We acknowledge the helpful discussions with Emanuele Raineri, Barcelona, Spain and with Wilfried Karmaus, Division of Epidemiology, Biostatistics, and Environmental Health, School of Public Health, University of Memphis, Memphis, Tennessee, USA. CNAG-CRG lab is a member of the Spanish National Bioinformatics Institute (INB), PRB2-ISCIII and is supported by grant PT13/0001 of the PE I+D+i 2013-2016, funded by ISCIII and FEDER. Work by CB at Leicester and by LZH at Munich was also supported the European Union FP7 project # 270194.

Background Whether the clinical or pathophysiologic significance of the “treatable trait” high blood eosinophil count in COPD is the same as for asthma remains controversial. We sought to determine the relationship between the blood eosinophil count, clinical characteristics and gene expression from bronchial brushings in COPD and asthma. Methods Subjects were recruited into a COPD (emphysema versus airway disease [EvA]) or asthma cohort (Unbiased BIOmarkers in PREDiction of respiratory disease outcomes, U‐BIOPRED). We determined gene expression using RNAseq in EvA (n = 283) and Affymetrix microarrays in U‐BIOPRED (n = 85). We ran linear regression analysis of the bronchial brushings transcriptional signal versus blood eosinophil counts as well as differential expression using a blood eosinophil > 200 cells/μL as a cut‐off. The false discovery rate was controlled at 1% (with continuous values) and 5% (with dichotomized values). Results There were no differences in age, gender, lung function, exercise capacity and quantitative computed tomography between eosinophilic versus noneosinophilic COPD cases. Total serum IgE was increased in eosinophilic asthma and COPD. In EvA, there were 12 genes with a statistically significant positive association with the linear blood eosinophil count, whereas in U‐BIOPRED, 1197 genes showed significant associations (266 positive and 931 negative). The transcriptome showed little overlap between genes and pathways associated with blood eosinophil counts in asthma versus COPD. Only CST1 was common to eosinophilic asthma and COPD and was replicated in independent cohorts. Conclusion Despite shared “treatable traits” between asthma and COPD, the molecular mechanisms underlying these clinical entities are predominately different., In a chronic obstructive pulmonary disease (COPD) cohort (EvA, n = 283), 12 genes, whereas in asthma cohort (UBIOPRED, n = 85), 1197 genes in bronchial epithelial brushes were correlated with a blood eosinophil count. The gene CST1 was common to eosinophilic asthma and COPD and was replicated in independent cohorts. Despite shared “treatable traits” between asthma and COPD, the molecular mechanisms underlying these clinical entities are predominately different.

Counting numbers of blood neutrophils is one of the most common laboratory tests in modern clinical medicine. In this report, we have tested the idea that immunoassay of major constituents of mature neutrophils might serve as proxy of cell counting and allow the development of rapid and simple point-of-care tests. The procedure may also allow for the estimate of the state of maturity of the circulating blood cells. Immunoassays for myeloperoxidase (MPO) and lactoferrin (LF) were used to measure the respective protein in whole blood extracts of 275 unselected hospitalized patient and in 51 healthy controls and leukemia patients of which eight were followed before, during and after remission treatment. MPO was correlated to neutrophil counts in the unselected hospitalized population (r = 0.95, p

Diagnosing persons infected by COVID-19 is key to the control of the pandemic. It has, however, become increasingly important to identify those who have had the infection by measurement of circulating antibodies against Sars-COV-2 of the IgM and IgG type. In this report we show the development of a rapid and sensitive point-of-care assay for the measurement of IgG antibodies against the two spike proteins, S1 and S2, of the Sars-COV-2 virus.MethodThe AgPlus electrochemical technology was applied and the S1 and S2 proteins were biotinylated and immobilized onto streptavidin coated magnetic particles as the capture component of the assay. The IgG antibodies bound to the particles were detected by anti-human IgG and the signal expressed as nC (nano Coulomb). Assay time was

Background: Thymidine kinase 1 (TK1) is an intracellular protein associated with DNA synthesis, expressed during the G1 phase and remained elevated through the M phase, with a potential as a biomarker for cell proliferation. In this study, we explore the possible use of TK1 in Hodgkin lymphoma (HL). Methods: Serum concentrations of TK1 (S-TK1) were measured in 46 newly diagnosed HL patients using prospectively collected biobanked serum samples. The samples were analyzed using a novel antibody-based TK1 immunosorbent assay (ELISA). Results: The concentrations of S-TK1 were elevated in HL patients compared with healthy controls (median 0.32 μg/L vs. 0.24 μg/L, P = 0.003). A further increase in S-TK1 was observed during the treatment. The S-TK1 concentrations were higher in patients with advanced stage disease, low B-Hb, elevated P-LD and in those with B-symptoms. A high ESR correlated with low S-TK1. Conclusions: The study results suggest that S-TK1, measured using a novel antibody-based assay, has the potential to be a biomarker in HL. However, while S-TK1 levels are elevated at baseline compared with healthy controls, a limited number of patients and comparatively short follow-up time render reliable conclusions difficult.

Objective: Neutrophil gelatinase-associated lipocalin (NGAL) is secreted by injured kidney cells as well as by activated neutrophils in response to bacterial infections. We assessed the influence of acute renal dysfunction on the association between plasma NGAL and sepsis. Methods: NGAL was measured daily in 138 critically ill patients. Simultaneous recordings of sepsis status and fluctuations in renal function were made. Results: Elevated NGAL was associated with sepsis independent of level of acute renal dysfunction. A cut-off value of 98 ng/mL distinguished sepsis from systemic inflammation with high sensitivity (0.77) and specificity (0.79). Conclusions: Plasma NGAL can help clinicians to identify bacterial infections in critically ill patients.

Aims Acute kidney injury (AKI) during acute heart failure (AHF) is common and associated with increased morbidity and mortality. The underlying pathophysiological mechanism appears to have prognostic relevance; however, the differentiation of true, structural AKI from hemodynamic pseudo‐AKI remains a clinical challenge. Methods and results The Basics in Acute Shortness of Breath Evaluation Study (NCT01831115) prospectively enrolled adult patients presenting with AHF to the emergency department. Mortality of patients was prospectively assessed. Haemoconcentration, transglomerular pressure gradient (n = 231) and tubular injury patterns (n = 253) were evaluated to investigate pathophysiological mechanisms underlying AKI timing (existing at presentation vs. developing during in‐hospital period). Of 1643 AHF patients, 755 patients (46%) experienced an episode of AKI; 310 patients (19%; 41% of AKI patients) presented with community‐acquired AKI (CA‐AKI), 445 patients (27%; 59% of AKI patients) developed in‐hospital AKI. CA‐AKI but not in‐hospital AKI was associated with higher mortality compared with no‐AKI (adjusted hazard ratio 1.32 [95%‐CI 1.01–1.74]; P = 0.04). Independent of AKI timing, haemoconcentration was associated with a lower two‐year mortality. Transglomerular pressure gradient at presentation was significantly lower in CA‐AKI compared to in‐hospital AKI and no‐AKI (P

Respiratory tract infections require early diagnosis and adequate treatment. With the antibiotic overuse and increment in antibiotic resistance there is an increased need to accurately distinguish between bacterial and viral infections. We investigated the diagnostic performance of calprotectin in respiratory tract infections and compared it with the performance of heparin binding protein (HBP) and procalcitonin (PCT). Biomarkers were analyzed in patients with viral respiratory infections and patients with bacterial pneumonia, mycoplasma pneumonia and streptococcal tonsillitis (n = 135). Results were compared with values obtained from 144 healthy controls. All biomarkers were elevated in bacterial and viral infections compared to healthy controls. Calprotectin was significantly increased in patients with bacterial infections; bacterial pneumonia, mycoplasma pneumonia and streptococcal tonsillitis compared with viral infections. PCT was significantly elevated in patients with bacterial pneumonia compared to viral infections but not in streptococcal tonsillitis or mycoplasma caused infections. HBP was not able to distinguish between bacterial and viral causes of infections. The overall clinical performance of calprotectin in the distinction between bacterial and viral respiratory infections, including mycoplasma was greater than performance of PCT and HBP. Rapid determination of calprotectin may improve the management of respiratory tract infections and allow more precise diagnosis and selective use of antibiotics.

Background: The adaptive as well as innate immunity is involved in JIA pathology. Neutrophils are key mediators of the innate immune response and is the most abundant cell type found in JIA synovial fluid. Studies of neutrophils in JIA have shown transcriptional abnormalities and neutrophil-derived S100A proteins have shown a potential role as biomarkers. Still, studies of neutrophils in JIA are scarce. Human neutrophil lipocalin (HNL), also known as neutrophil gelatinase-associated lipocalin (NGAL), is a protein found in the secondary granules of neutrophil granulocytes. HNL can be found in epithelial cells as well, but only in its monomeric form. The dimeric form is only produced by neutrophil granulocytes. HNL resides in the secondary granules and is released upon stimulation, making HNL a unique marker of primed and activated neutrophil granulocytes, compared to myeloperoxidase (MPO) that resides in the primary granules and is released when neutrophils are activated, but also found in monocytes. Objectives: To examine levels of the dimeric form of human neutrophil lipocalin (dHNL), to reveal if neutrophil granulocytes are primed in JIA, also analysis of myeloperoxidase MPO to reveal neutrophil activation. We aimed to compare the analyses to healthy controls and correlate the results to established measures of disease activity. Methods: Blood samples from 75 patients with JIA (68% females) and 16 healthy controls were analyzed regarding HNL, using a dimer ELISA assay (Diagnostics Development, Uppsala, Sweden) specifically detecting the dimeric form of HNL (dHNL). We also analysed MPO (Diagnostics Development, Uppsala, Sweden), white blood cell count, neutrophil granulocyte cell count, ESR and CRP. All categories of JIA except the systemic category were included. Patient/parent and the physician filled out a global health assessment on a VA-scale (0-10). The number of active joints at sampling was collected and patients were classified according to the ILAR criteria. The participants with JIA had a median age of 12.1 (IQR: 7.7-15.3) years, the control group 5.3 (IQR: 2.0-9.5) years. Results: The serum levels of dHNL and MPO were significantly elevated compared to healthy controls, (p The levels of dHNL correlated best to the count of neutrophil granulocytes (rs =0.54, p Conclusion: The increased levels of the dimeric HNL in serum confirmed the involvement of neutrophil granulocytes in JIA although dHNL did not correlate with disease activity. The mechanisms by which neutrophils are primed and activated in JIA, however, still remain an enigma. Disclosure of Interests: Lillemor Berntson Consultant for: AbbVie, Speakers bureau: AbbVie, Ulrika Kihlberg: None declared, Per Venge: None declared

Purpose To assess the value of dimeric neutrophil-gelatinase associated lipocalin (NGAL) as an early marker of bacterial infection and its response to antibiotic therapy in intensive care unit (ICU) patients. Materials & methods We measured daily plasma dNGAL in 198 patients admitted to a mixed ICU. Likelihood of infection was determined with International Sepsis Forum criteria. We measured dNGAL in 145 healthy controls to establish normal values. Results ICU patients had higher dNGAL than healthy controls. A suspected or confirmed infection was independently associated with 90% (95% CI 15–215%) higher dNGAL than absence of infection. We observed no association between acute kidney injury and dNGAL. Diagnostic accuracy at antibiotic treatment initiation, assessed with area under the receiver-operating characteristics curve (AUC-ROC), for dNGAL was 0.70 (95% CI 0.60–0.79). AUC-ROC for dNGAL 24 h before antibiotic treatment initiation was 0.54 (95% CI 0.41–0.66). The mean (95% CI) change of dNGAL in the first 2 days after appropriate antibiotic therapy initiation was −31 (−49,−13)%. Conclusions In our cohort of ICU patients, plasma dNGAL was associated with presence of bacterial infections independent of AKI but it performed poor as a predictor of infections. Following antibiotic therapy, dNGAL markedly decreased–supporting further exploration of dNGAL-guided antibiotic de-escalation.

The correct diagnosis of acute infections as to bacteria, mycoplasma or virus is a clinical challenge and has a great impact on the therapeutic decisions. Current diagnostic tests of mycoplasma pneumoniae infections of the respiratory tract such as PCR and serology are either somewhat unreliable or slow and do not entirely meet the clinical needs of accurate and fast diagnosis. The aim of this report was to examine a panel of candidate biomarkers and their capacity to distinguish mycoplasma pneumoniae respiratory infections from respiratory infections caused by either bacterial or virus. Method Patients with confirmed etiology of their acute respiratory infections (n = 156) were included of which 28 patients were diagnosed with mycoplasma pneumoniae. Blood was taken before any antibiotics treatment and analysed for Azurocidin (HBP), Calprotectin, CRP, Human Neutrophil Lipocalin (HNL), Interferon γ-induced Protein 10 kDa (IP-10), Procalcitonin (PCT), Thymidine Kinase 1 (TK1), TNF-Related Apoptosis-Inducing Ligand (TRAIL). Results Individually the concentrations of IP-10, TK1 and P-HNL distinguished mycoplasma pneumoniae from bacterial infections with AUCs of 0.79–0.85. However, in combination, TK1 with either IP-10 or P-HNL showed an AUC of 0.97–0.95. In the distinction between mycoplasma pneumoniae and viral respiratory infections CRP, Calprotectin and TRAIL showed individual AUCs of 0.94–0.84. Together with either P-HNL dimer or PCT, CRP showed AUCs of 0.97. Conclusion Our results indicate that it may be possible to design useful diagnostic algorithms of biomarkers that could help distinguish mycoplasma pneumoniae from respiratory infections caused by bacteria or virus. The development of rapid point-of-care assays based on such algorithms could be clinically useful tools in the therapeutic decision-making.

BACKGROUND: The FRISC-II trial was the first randomised trial to show a reduction in death or myocardial infarction with an early invasive versus a non-invasive treatment strategy in patients with non-ST-elevation acute coronary syndrome. Here we provide a remaining lifetime perspective on the effects on all cardiovascular events during 15 years' follow-up.METHODS: The FRISC-II prospective, randomised, multicentre trial was done at 58 Scandinavian centres in Sweden, Denmark, and Norway. Between June 17, 1996, and Aug 28, 1998, we randomly assigned (1:1) 2457 patients with non-ST-elevation acute coronary syndrome to an early invasive treatment strategy, aiming for revascularisation within 7 days, or a non-invasive strategy, with invasive procedures at recurrent symptoms or severe exercise-induced ischaemia. Plasma for biomarker analyses was obtained at randomisation. For long-term outcomes, we linked data with national health-care registers. The primary endpoint was a composite of death or myocardial infarction. Outcomes were compared as the average postponement of the next event, including recurrent events, calculated as the area between mean cumulative count-of-events curves. Analyses were done by intention to treat.FINDINGS: At a minimum of 15 years' follow-up on Dec 31, 2014, data for survival status and death were available for 2421 (99%) of the initially recruited 2457 patients, and for other events after 2 years for 2182 (89%) patients. During follow-up, the invasive strategy postponed death or next myocardial infarction by a mean of 549 days (95% CI 204-888; p=0·0020) compared with the non-invasive strategy. This effect was larger in non-smokers (mean gain 809 days, 95% CI 402-1175; pinteraction=0·0182), patients with elevated troponin T (778 days, 357-1165; pinteraction=0·0241), and patients with high concentrations of growth differentiation factor-15 (1356 days, 507-1650; pinteraction=0·0210). The difference was mainly driven by postponement of new myocardial infarction, whereas the early difference in mortality alone was not sustained over time. The invasive strategy led to a mean of 1128 days (95% CI 830-1366) postponement of death or next readmission to hospital for ischaemic heart disease, which was consistent in all subgroups (pINTERPRETATION: During 15 years of follow-up, an early invasive treatment strategy postponed the occurrence of death or next myocardial infarction by an average of 18 months, and the next readmission to hospital for ischaemic heart disease by 37 months, compared with a non-invasive strategy in patients with non-ST-elevation acute coronary syndrome. This remaining lifetime perspective supports that an early invasive treatment strategy should be the preferred option in most patients with non-ST-elevation acute coronary syndrome.FUNDING: Swedish Heart-Lung Foundation, Swedish Foundation for Strategic Research, and Uppsala Clinical Research Center.

The distinction between acute infections of bacterial or viral causes is clinically important, but often very difficult even for experienced doctors. Previous studies indicated that serum measurements of HNL (Human Neutrophil Lipocalin) might be a superior diagnostic means in this regard, but also indicated that the antibody conformation of the HNL assay might have an impact on the diagnostic performance. The aim of the present report was to examine this further. Methods Several different (n = 24) HNL ELISA assays were developed using different combinations of monoclonal and polyclonal HNL antibodies. Sera were collected from healthy persons (n = 188) and from 155 patients with acute infections before any antibiotics treatment. The patients were diagnosed as having bacterial (n = 69) or viral causes (n = 86) of their infections. Plasma and serum were also examined by Western blotting using HNL-specific polyclonal antibodies. Results The optimal assay format for the distinction between bacterial and viral infection resulted in an area under the receiver operating characteristics curve (AuROC) for S-HNL of 0.98. (95% CI 0.94–1.00) as compared to 0.83 (0.76–0.88) for blood neutrophil counts and 0.69 (0.61–0.76) for S-CRP. Results also showed that different assay formats of HNL identified monomeric and dimeric HNL differently, the monomeric HNL being elevated in viral infections and the dimeric HNL being elevated in bacterial infections. Conclusion We conclude that serum measurement of HNL is a superior diagnostic means to distinguish between acute infections caused by bacteria or virus. For optimal clinical performance the immunoassay should address conformational epitopes in the dimeric HNL.

Background Acute infections affect all of us at least once or twice a year. Sometimes the infection prompts a visit to our doctor, and the question asked by the patient and the doctor is whether the infection should be treated with antibiotics or not. This is an important question because unnecessary prescription of antibiotics adds to the increasing problem of antibiotics resistance. Objective means to determine whether the infection is caused by bacteria or virus, therefore, are necessary tools for the doctor. Content White blood cell counts, C-reactive protein, and other acute-phase reactants in blood are important tools and are commonly used, but unfortunately lack in sensitivity and specificity. In this review we describe some novel biomarkers with increased clinical performance in this regard. The superior biomarker is human neutrophil lipocalin (HNL), a protein released from activated blood neutrophils. HNL may be measured in serum, plasma, or in whole blood after activation with a neutrophil activator. The diagnostic accuracy in the distinction between bacterial and viral acute infections was shown to be in the range of 90%–95% when measured in serum or activated whole blood. Summary A point-of-care assay for the measurement of HNL in whole blood is currently being developed, which will allow the diagnosis of acute infections within 5–10 min. For certain indications, HNL measurement may be complemented by 1 or 2 other biomarkers, which may increase the diagnostic discrimination between bacterial and viral infections even further.

Background Prolyl carboxypeptidase (PRCP) is involved in the regulation of body weight, likely by hydro-lysing alpha-melanocyte-stimulating hormone and apelin in the hypothalamus and in the periphery. A link between PRCP protein concentrations in plasma and metabolic disorders has been reported. In this study, we investigated the distribution of circulating PRCP activity and assessed its relation with body weight and adipose tissue in obese patients and patients who significantly lost weight. Methods PRCP activity was measured using reversed-phase high-performance liquid chromatography in different isolated blood fractions and primary human cells to investigate the distribution of circulating PRCP. PRCP activity was measured in serum of individuals (n = 75) categorized based on their body mass index (BMI < 25.0; 25.0–29.9; 30.0–39.9; 40.0 kg/ m2) and the diagnosis of metabolic syndrome. Differences in serum PRCP activity were determined before and six months after weight loss, either by diet (n = 45) or by bariatric surgery (n = 24). Potential correlations between serum PRCP activity and several metabolic and biochemical parameters were assessed. Additionally, plasma PRCP concentrations were quantified using a sensitive ELISA in the bariatric surgery group. Results White blood cells and plasma contributed the most to circulating PRCP activity. Serum PRCP activity in lean subjects was 0.83 ± 0.04 U/L and increased significantly with a rising BMI (p

The distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) in serum distinguishes acute infections with high accuracy, but in the emergency setting the assay time should be15-20min, which excludes the use of serum samples. The aim was therefore to develop a novel rapid assay principle and test its clinical performance.Serum and neutrophils obtained from 84 infected and 20 healthy subjects were used in the experimental study. 725 subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the clinical study. HNL was measured in EDTA-plasma by ELISA or in heparinized whole blood after fMLP activation by a prototype point-of-care assay.Increased release of HNL from neutrophils after activation with fMLP was seen already after 5 min incubation. The release of HNL from purified neutrophils after 15 min incubation with fMLP was significantly correlated to the HNL concentrations in serum obtained from the same patient (r = 0.74, p0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the ROC-curves were 0.95 (95% CI 0.91-0.97) and 0.88 (95% CI 0.84-0.91) for HNL in fMLP-activated whole blood and EDTA-plasma, respectively, (p0.001) and in the distinction between bacterial and viral infections 0.91 (95% CI 0.86-0.95) and 0.76 (95% CI 0.70-0.81), respectively (p0.001).The clinical performance of HNL in fMLP-activated whole blood was superior to HNL in EDTA-plasma and similar to HNL in serum. The procedure can be adopted for point-of-care testing with response times of15 min.

The importance of sex on cardiac troponin levels is increasingly recognized. We investigated whether the entities associated with troponin leakage and the prognostic consequences thereof would differ between elderly men and women from the community.Cardiac troponin I (cTnI) levels were measured using a high-sensitivity assay (Abbott Laboratories) in 70-year old men (n = 502) and women (n = 502) from the PIVUS study. All study participants were followed up for 10 years regarding all-cause mortality and incident cardiovascular (CV) disease.Median cTnI levels were 4.1 and 3.0 ng/L in men and women, respectively (p0.001). By multiple linear regression, the relative contribution of lower left-ventricular ejection fraction and ischemic ECG changes to cTnI levels was greater in men compared to women. For other clinical and echocardiographic variables, similar associations were found. cTnI independently predicted all-cause mortality in men (n = 93 [18.5%]; hazard ratio [HR] 1.38 [1.12-1.70]) and women (n = 62 [12.4%]; HR 1.59 [1.11-2.28]) but not incident CV disease in subjects being CV healthy at baseline (n = 163/857). The interaction terms of sex on the associations of cTnI with both outcomes were non-significant. Sex-specific cut-offs did not improve prognostication. Variations in the pattern of entities associated with cTnI leakage had no impact on event rates.We found some differences in the entities associated with higher cTnI levels in elderly community-dwelling men and women. However, this did not translate into differences in the associations of cTnI with adverse outcome.

Background: Established cardiovascular risk markers, such as hypertension, are associated with increased risk of brain infarcts. The newer markers N-terminal pro-brain natriuretic peptide, troponin I, C-reactive protein, and cystatin C may affect the risk of cardiovascular events and potentially, thereby, also stroke. We investigated the association between established and new risk markers for cardiovascular disease and brain infarcts detected by magnetic resonance imaging (MRI) at age 75. Methods: Four hundred six randomly selected subjects from the Prospective Investigation of the Vasculature in Uppsala Seniors study were examined with MRI of the brain at age 75. Blood samples, measurements, and dedicated questionnairesatage70wereusedforanalysisofriskmarkers.Ahistoryofdiseaseshadbeen obtained at age 70 and 75. MRI was evaluated regarding lacunar and cortical infarcts. Univariate associations between outcomes and risk markers were assessed with logistic regression models. Results: One or more infarcts were seen in 23% of the subjects (20% had only lacunar infarcts, 1% had only cortical infarcts, and 2% had both). Hypertension (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.4, 4.7) and obesity (OR 1.3; CI 1.0, 1.8) were significantly associated with increased risk of brain infarction. The newer risk markers were not significantly associated with the brain infarcts. Conclusions: The new markers were not associated with the predominantly lacunar infarcts in our 75-year-old population, why troponin I and NT-proBNP may be associated mainly with cardioembolic infarcts as shown

Whereas elevated cardiac troponin (cTn) concentrations i.e. above the 99th percentile of healthy reference population (recommended cutoff for the diagnosis of myocardial infarction) are well-documented in healthy individuals after prolonged and/or intensive exercises such as marathons, data on less-strenuous sports are scarce. Therefore, our aim was to investigate cTnI and cTnT release in response to recreational resistance training, here a single-bout of 1-h kettlebell workout.Serum samples were collected from 11 apparently healthy volunteers the previous day (pre-exercise), three hours after the kettlebell class (post-exercise), the next day and three days later. The aliquoted samples were analyzed with Abbott Laboratories' Architect high-sensitivity (hs)-cTnI assay (limit of detection, LoD = 2 ng/L), our 3+1-type cTnI assay free from cTn-specific autoantibody interference (LoD = 3 ng/L) and Roche Diagnostics' hs-cTnT assay (LoD = 5 ng/L).The post-exercise cTn concentrations were significantly higher than the pre-exercise values (median 5.5-9.6 ng/L vs.LoD, P0.05 for all) and they correlated strongly between the three assays (Spearman r = 0.881-0.960, P0.001 for all). Furthermore, a few post-exercise concentrations even exceeded the 99th percentile of Architect hs-cTnI (26 ng/L, n = 2) and/or hs-cTnT (14 ng/L, n = 4). The cTn concentrations returned to baseline during the three days of follow-up.Our study demonstrates abnormally elevated cTns with well-validated sensitive cTn assays after resistance training. This confirms that different kinds of recreational physical activity are yet another confounder that may affect the determination and use of 99th percentile reference values. Therefore, exercise-associated changes should be carefully addressed as part of the evaluation what is "normal cTn".

Background Measurement of N-terminal pro B-type natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI) might be useful for monitoring of cardiovascular disease in the elderly. However, it is not clear whether changes in these biomarkers are associated with changes in the cardiovascular risk profile and if this pattern could be modified by changes in lifestyle habits or medications. Methods We measured levels of NT-proBNP and cTnI in community-dwelling subjects (PIVUS study) upon visits scheduled at age 70 ( n =1007), 75 ( n =825) and 80 ( n =602). The associations of these biomarkers with repeated measurements of clinical variables (risk factors, lifestyle habits, echocardiographic data and medications) were investigated using sex-adjusted linear mixed random effect models. Results NT-proBNP and cTnI were positively associated with increasing age. NT-proBNP, but not cTnI, was affected by changes of renal function and the degree of obesity. NT-proBNP was more closely related than cTnI to changes in echocardiographic estimates of cardiac geometry and function. Biomarker levels and/or their changes were inversely associated with a physically more active lifestyle (both NT-proBNP and cTnI) and statin treatment at age 70 (only cTnI). Changes in smoking status or antihypertensive treatment had no effect on biomarker levels. Conclusions Changes in NT-proBNP and cTnI levels are associated with different patterns of cardiovascular disease burden when using a longitudinal approach. However, levels of both biomarkers and their changes also reflect changes in the cardiovascular risk profile that might be modifiable. This is an important aspect for the use of any cardiovascular biomarker in an elderly population.

The distinction between bacterial and viral causes of infections of the respiratory tract is a major but important clinical challenge. We investigated the diagnostic performance of human neutrophil lipocalin (HNL) in respiratory tract infections compared to those of C-reactive protein (CRP) and procalcitonin (PCT). Patients were recruited from the emergency department and from a primary care unit ( n = 162). The clinical diagnosis with regard to bacterial or viral cause of infection was complemented with objective microbiological/serological testing. HNL was measured in whole blood after preactivation with the neutrophil activator formyl-methionine-leucine-phenylalanine (fMLP) (B-HNL), and CRP and PCT were measured in plasma. Head-to-head comparisons of the three biomarkers showed that B-HNL was a superior diagnostic means to distinguish between causes of infections, with areas under the concentration-time curve (AUCs) of receiver operating characteristic (ROC) analysis for HNL of 0.91 (95% confidence interval [CI], 0.83 to 0.96) and 0.92 (95% CI, 0.82 to 0.97) for all respiratory infections and for upper respiratory infections, respectively, compared to 0.72 (95% CI, 0.63 to 0.80) and 0.68 (95% CI, 0.56 to 0.79) for CRP, respectively ( P = 0.001). In relation to major clinical symptoms of respiratory tract infections (cough, sore throat, stuffy nose, and signs of sinusitis), AUCs varied between 0.88 and 0.93 in those patients with likely etiology (i.e., etiology is likely determined) of infection, compared to 0.63 and 0.71 for CRP, respectively, and nonsignificant AUCs for PCT. The diagnostic performance of B-HNL is superior to that of plasma CRP (P-CRP) and plasma PCT (P-PCT) in respiratory tract infections, and the activity specifically reflects bacterial challenge in the body. The rapid and accurate analysis of HNL by point-of-care technologies should be a major advancement in the diagnosis and management of respiratory infections with respect to antibiotic treatment.

Visceral leishmaniasis (VL) is the most severe form of leishmaniasis. Recent findings indicate that dendritic cells have a key role in the defense against the Leishmania parasite and that the activity of this cell may be modified by the eosinophil secretory protein eosinophil-derived neurotoxin (EDN). We hypothesized that the interactions between dendritic cells and EDN might be of importance in the disease development. Cellular content of EDN was analyzed by ELISA. The single-nucleotide polymorphisms at positions 405, 416, and 1122 in the EDN gene were analyzed by real-time PCR with TaqMan® reagents. The study cohorts comprised 239 Sudanese subjects (65 healthy controls and 174 with VL) and 300 healthy Swedish controls. The eosinophil content of EDN was lower in VL as compared with controls (p C) genotype distribution was similar among Swedish and Sudanese controls, whereas VL subjects had a higher prevalence of the EDN405-GG genotype (p < 0.0001). The content of EDN in the eosinophils was closely linked to the EDN405 polymorphism (p = 0.0002). Our findings suggest that the predisposition to acquire VL is related to the genetic polymorphism of the EDN gene and the reduced production by the eosinophil of this gene product.

BACKGROUND: Efficient rule-out of acute myocardial infarction (MI) facilitates early disposition of chest pain patients in emergency departments (ED). Point-of-care (POC) cardiac troponin (cTn) may improve patient throughput. We compared the diagnostic accuracy of a novel cTnI test (Minicare cTnI, Philips), with current POC cTnI (I-Stat, Abbott) and high-sensitivity central laboratory cTnI (hs-cTnI; Architect, Abbott) assays.METHODS: The clinical performance of the assays were compared in samples from 450 patients from a previous clinical evaluation of Minicare cTnI.RESULTS: Minicare cTnI correlated with Architect hs-cTnI (r(2)=0.85, pCONCLUSIONS: The Minicare cTnI POC assay may become useful for prompt and safe ruling-out of AMI in ED patients with suspected AMI using a guideline supported 0/3h sampling protocol.

Knowledge on the contribution of protein glycosylation in host defense antimicrobial peptides is still scarce. We have studied here how the post-translational modification pattern modulates the antimicrobial activity of one of the best characterized leukocyte granule proteins. The human eosinophil cationic protein (ECP), an eosinophil specific granule protein secreted during inflammation and infection, can target a wide variety of pathogens. Previous work in human eosinophil extracts identified several ECP native forms and glycosylation heterogeneity was found to contribute to the protein biological properties. In this study we analyze for the first time the antimicrobial activity of the distinct native proteins purified from healthy donor blood. Low and heavy molecular weight forms were tested on Escherichia coli cell cultures and compared with the recombinant non-glycosylated protein. Further analysis on model membranes provided an insight towards an understanding of the protein behavior at the cytoplasmic membrane level. The results highlight the significant reduction in protein toxicity and bacteria agglutination activity for heavy glycosylated fractions. Notwithstanding, the lower glycosylated fraction mostly retains the lipopolysaccharide binding affinity together with the cytoplasmic membrane depolarization and membrane leakage activities. From structural analysis we propose that heavy glycosylation interferes with the protein self-aggregation, hindering the cell agglutination and membrane disruption processes. The results suggest the contribution of post-translational modifications to the antimicrobial role of ECP in host defense.

BACKGROUND Late enhancement MRI (LE-MRI) and cardiac troponin I (cTnI) are sensitive methods to detect subclinical myocardial injury. We sought to investigate the relation between plasma concentrations of cTnI measured with a high-sensitivity assay (hs-cTnI) and the development of unrecognized myocardial infarctions (UMIs) detected with LE-MRI. METHODS After approval from the ethics committee and written informed consent were obtained, LE-MRI was performed on 248 randomly selected community-living 70-year-old volunteers and hs-cTnI was determined with a highly sensitive premarket assay. Five years later these individuals were invited to a second LE-MRI, and 176 of them (82 women, 94 men), who did not have a hospital diagnosis of MI, constitute the present study population. LE-MR images were analyzed by 2 radiologists independently and in a consensus reading, blinded to any information on previous disease or assessments. RESULTS New or larger UMIs were detected in 37 participants during follow-up. Plasma concentrations of hs-cTnI at 70 years of age, which were mainly within what is considered to be the reference interval, were related to new or larger UMIs at 75 years of age with an odds ratio of 1.98 per 1 unit increase in ln-transformed cTnI (95% CI, 1.17–3.35; P = 0.010). Plasma concentrations of hs-cTnI at 70 years of age were associated with the volumes of the UMIs detected at 75 years of age (P = 0.028). CONCLUSIONS hs-cTnI in 70-year-old community-living women and men was associated with the development of MRI-detected UMIs within 5 years.

Objectives The distinction between bacterial and viral causes of acute infections is a major clinical challenge. In this report we investigate the diagnostic performance in this regard of nine candidate biomarkers together with HNL (Human Neutrophil Lipocalin). Methods Blood was obtained from patients with symptoms of infectious (n = 581). HNL was measured in whole blood (B-HNL) after pre-activation with the neutrophil activator fMLP or in plasma (P-HNL). Azurocidin also known as heparin-binding protein (HBP), Calprotectin, PMN-CD64, CRP (C-reactive protein), IP-10 (Interferon γ-induced Protein 10 kDa), PCT (Procalcitonin), TK1 (Thymidine kinase 1), TRAIL (TNF-related apoptosis-inducing ligand) were measured in plasma/serum. Area under the ROC (receiver operating characteristics) curve (AuROC) was used for the evaluation of the clinical performance of the biomarkers. Results Side-by-side comparisons of the ten biomarkers showed large difference in the AuROC with B-HNL being the superior biomarker (0.91, 95% CI 0.86–0.95) and with the other nine biomarkers varying from AuROC of 0.63–0.79. The combination of B-HNL with IP-10 and/or TRAIL increased the diagnostic performance further to AuROCs of 0.94–0.97. The AuROCs of the combination of CRP with IP-10 and/or TRAIL were significantly lower than combinations with B-HNL 0.87 (95% CI 0.83–0.91). Conclusion The diagnostic performance of whole blood activated HNL was superior in the distinction between bacterial or viral infections. The addition of IP-10 and/or TRAIL to the diagnostic algorithm increased the performance of B-HNL further. The rapid analysis of HNL, reflecting bacterial infections, together with biomarkers reflecting viral infections may be the ideal combination of diagnostic biomarkers of acute infections.

Recurrent Pyoderma Gangrenosum and Cystic Acne Associated with Leucocyte Adhesion Deficiency due to Novel Mutations in ITGB2 : Successful Treatment with Infliximab and Adalimumab

Objectives: Pentraxin 3 (PTX3) is the prototype of the long pentraxin family. PTX3 is involved in inflammatory processes affecting the cardiovascular system, and PTX3 levels have been shown to be elevated and independently prognostic in ST-elevation myocardial infarction. Data on PTX3 levels in non-ST-elevation acute coronary syndrome (NSTE-ACS), in contrast, are limited. The aim of the present analysis was to investigate the implications of PTX3 levels in a fairly large sample of NSTE-ACS patients and in comparison to levels of C-reactive protein (CRP). Design and methods: We measured levels of PTX3 and CRP in both 82 healthy controls and 401 NSTE-ACS patients from the GUSTO IV study, and studied the associations of these biomarkers to clinical data and 1-year mortality. Results: NSTE-ACS patients had significantly higher median PTX3 levels compared to healthy controls (3.8 vs. 1.9 mu g/L; p < 0.001). PTX3 levels in patients with NSTE-ACS were independently related to female sex and cardiac troponin T levels, but not to age or cardiovascular risk factors. PTX3 levels were higher in patients who died within 1 year but did not emerge as an independent predictor of 1-year mortality (adjusted OR 1,2 [95% Cl 0.6-2.31). This was in contrast to CRP (adjusted OR 1.5 [95 Conclusions: PTX3 levels are elevated in NSTE-ACS. However, the prognostic information provided by PTX3 levels is limited and inferior compared to CRP. Our data, thus, do not support the measurement of PTX3 in patients with NSTE-ACS. (C) 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

The mid-regional part of the prohormone of adrenomedullin (MR-proADM) is emerging as a novel risk indicator in patients with cardiac disease. We investigated MR-proADM levels and their changes over 5 years in elderly community-dwellers, together with the underlying cardiovascular and metabolic conditions, and the prognostic implications of these measurements.MR-proADM was analyzed using a sandwich immunoassay (Thermo Fisher Scientific) in participants from the PIVUS study. Measurements were performed at 70 (n=1002) and 75 years of age (n=795) together with various measurements of other markers of cardiovascular function. In cross-sectional analyses, MR-proADM was independently related to current smoking, renal dysfunction, obesity, lower left-ventricular ejection fraction, and higher levels of N-terminal pro-B-type natriuretic peptide and C-reactive protein. There were no independent associations to other cardiovascular risk factors or vascular pathologies. MR-proADM levels predicted all-cause mortality during 8.0 years of follow-up independent of cardiovascular risk indicators (adjusted HR 5.1 [95% CI 2.8-9.5]; p0.001) using results obtained at 70 and 75 years as updated covariates. Baseline MR-proADM levels improved prognostic discrimination (IDI=0.018 [p=0.001]). Also the change in MR-proADM levels over time independently predicted all-cause mortality occurring after 75 years (adjusted HR 13.4 [95% CI 3.5-50.5]; p0.001).MR-proADM levels in the elderly integrate information on several relevant aspects in cardiovascular disease, namely cardiovascular risk factors including obesity, low-grade inflammation, renal dysfunction and left-ventricular abnormalities. Furthermore, MR-proADM and its changes over time predicted mortality, and might provide utility as an indicator of the overall cardiovascular risk burden.

Different molecular forms of urinary neutrophil gelatinase-associated lipocalin (NGAL) have recently been discovered. We aimed to explore the nature, source and discriminatory value of urinary NGAL in intensive care unit (ICU) patients.We simultaneously measured plasma NGAL (pNGAL), urinary NGAL (uNGAL), and estimated monomeric and homodimeric uNGAL contribution using Western blotting-validated enzyme-linked immunosorbent assays [uNGAL(E1) and uNGAL(E2)] and their calculated ratio in 102 patients with the systemic inflammatory response syndrome and oliguria, and/or a creatinine rise of25 μmol/L.Bland-Altman analysis demonstrated that, despite correlating well (r = 0.988), uNGAL and uNGAL(E1) were clinically distinct, lacking both accuracy and precision (bias: 266.23; 95% CI 82.03-450.44 ng/mg creatinine; limits of agreement: -1,573.86 to 2,106.32 ng/mg creatinine). At best, urinary forms of NGAL are fair (area under the receiver operating characteristic [AUROC] ≤0.799) predictors of renal or patient outcome; most perform significantly worse. The 44 patients with a primarily monomeric source of uNGAL had higher pNGAL (118.5 ng/ml vs. 72.5 ng/ml; p0.001), remaining significant following Bonferroni correction.uNGAL is not a useful predictor of outcome in this ICU population. uNGAL patterns may predict distinct clinical phenotypes. The nature and source of uNGAL are complex and challenge the utility of NGAL as a uniform biomarker.

Previous studies showed that the biological activity and the eosinophil content of eosinophil cationic protein (ECP, RNase 3) are determined by single-nucleotide polymorphisms (SNPs) in the ECP (RNase3) gene. In this study, we report the prevalence of a common SNP in the eosinophil protein x/eosinophil-derived neurotoxin (EPX/EDN, RNase2) and the association with the cellular contents of EPX/EDN and ECP. The genes were sequenced and the EPX/EDN405(G>C) rs2013109 SNPs were also determined by TaqMan 5′nuclease allelic discrimination assay. ECP and EPX/EDN in purified eosinophils or in whole blood extracts were analysed by sensitive immunoassays. The study included 379 non-allergic and allergic subjects. The genotype prevalence of the EPX/EDN405(G>C) polymorphism was GG 59%, GC 36% and CC 6%. The cellular contents of ECP and EPX/EDN were related in a reciprocal fashion with the sums of the protein contents being constant. The contents were associated with the ECP562(G>C) rs2233860 and EPX/EDN405(G>C) gene polymorphisms. The cellular content of eosinophil peroxidase (EPO) was not associated with the ECP and EPX/EDN genotypes. The prevalence of the EPX/EDN405(G>C) genotypes and the contents of the proteins were similar in non-allergic and allergic subjects.The production and storage of the two ancestral proteins, ECP and EPX/EDN likely share common regulatory mechanisms, which result in opposing productions of the two proteins.

Progression rate of disease processes in smoke-induced lung injuries varies greatly. Diverse pathophysiological mechanisms may trigger these divergences. The aim of this study was to evaluate whether circulating markers of monocytes/macrophages and/or neutrophil [i.e. lysozyme (LZM) or myeloperoxidase (MPO)] were associated with reduced values of diffusion capacity (DL,CO), which is considered to serve as a mirror of pulmonary microvascular derangement and an early sign of tissue remodelling in smokers. Data obtained from 134 smokers (GOLD stage ≤1) and 24 matched healthy non-smoking volunteers were evaluated in a cross-sectional study design. Lung function tests as well as single breath test of DL,CO were assessed according to ATS/ERS guidelines. Biomarkers were measured in serum by means of sensitive immunoassays. A subgroup of smokers with normal lung function was created to minimize confounding, by excluding datasets showing significant airflow limitation and abnormally high values of carboxy haemoglobin (COHb), the latter indicating recent smoking. The capacity of serum lysozyme to correctly identify abnormally low values of DL,CO (i.e.1·9SD units), tended to be higher than that of Myeloperoxidase as assessed by analyses of receiver operated curves (ROC; AUC 0·81, 95%CI: 0·69-0·89 versus AUC 0·67, 95%CI: 0·60-0·81). It is concluded that serum levels of lysozyme, reflecting mainly activated monocytes/macrophages but also neutrophils, were significantly associated with isolated decrements of DL,CO in smokers with normal lung function tests. This suggests monocytes/macrophages to have a significant mechanistic role in early phases of the disease process and/or pulmonary microvascular damage.

BACKGROUND A rise or fall of cardiac troponin is a prerequisite for the diagnosis of acute myocardial infarction. Defining significant changes requires knowledge of both biological and analytical variation. The short-term biological variation of cardiac troponin in healthy individuals is 3%–48%. However, healthy individuals may not be representative for patients in whom cardiac troponin measurement is often of clinical importance. Therefore, we studied the individual variation of cardiac troponin in patients with symptoms of stable coronary artery disease. METHODS Twenty-four patients scheduled for elective coronary angiography were included. Blood samples were drawn once at enrollment and serially at six 4-h intervals on the day before coronary angiography. Cardiac troponin was measured with hs-cTn assays from Abbott Laboratories (premarket cTnI assay) and Roche Diagnostics (Elecsys® cTnT assay with two different lots). RESULTS The short-term individual variation in cardiac troponin I (cTnI) was 14%, the reference change value (RCV) 49%, and RCV-log-normal (rise/fall) 54%/−35%. The corresponding values for cTnT were 7%, 23%, and 26%/−21%. The long-term variation for cTnI was 24%, RCV 69%, and RCV-log-normal (rise/fall) 97%/−49%. The corresponding values for cTnT were 11%, 32%, and 37%/−27%. CONCLUSIONS The short-term individual variation of cardiac troponin in patients with symptoms of stable coronary artery disease is similar to the biological variation previously demonstrated in healthy individuals. Our results suggest that a change in cardiac troponin concentrations of >50% can be used in attempting to diagnose acute myocardial injury. To detect significant long-term changes in cardiac troponin concentrations, larger changes will be required.

The levels of N-terminal pro B-type natriuretic peptide (NT-proBNP) are closely related to cardiac abnormalities and adverse outcomes in the general population. However, little is known about the course of NT-proBNP levels over time, the underlying conditions, and the prognostic effect of changes. To investigate these issues, we measured the NT-proBNP levels (Elecsys 2010, Roche Diagnostics) in community-dwellers participating in the Prospective Investigation of the Vasculature in Uppsala Seniors study at 70 (n = 1,005) and 75 (n = 817) years of age. The total follow-up was 8.0 years. In subjects with available results from both examinations, the median NT-proBNP levels increased from 106 pg/ml (25th to 75th percentile 62 to 174) to 125 pg/ml (25th to 75th percentile 73-234; p0.001). The change in NT-proBNP levels was positively and independently related to male gender, baseline information on ischemic electrocardiographic changes, renal dysfunction, impaired left ventricular ejection fraction, and intercurrent cardiovascular events (e.g., myocardial infarction, stroke, or coronary revascularization). The change in NT-proBNP levels independently predicted mortality after the measurements at 75 years of age (all-cause mortality, adjusted hazard ratio 2.4, 95% confidence interval 1.6 to 3.6; cardiovascular mortality, adjusted hazard ratio 2.3, 95% confidence interval 1.2 to 4.5). Compared to those without significant NT-proBNP changes (n = 606), subjects with increasing levels (n = 162) had markedly increased all-cause mortality (adjusted hazard ratio 4.3, 95% confidence interval 2.1 to 8.8). No subject with decreasing NT-proBNP levels (n = 49) died. In conclusion, repeat measurements of NT-proBNP might add useful information to the routine clinical assessment in subjects aged ≥ 70 years, because changes in their levels were associated with cardiovascular risk indicators and strongly predictive of mortality.

Biomarkers may be of value to identify individuals at risk of developing atrial fibrillation (AF). Using a multimarker approach, this study investigated if the biomarkers; NT-proBNP, high-sensitivity cardiac troponin (hs-cTn), growth differentiation factor-15 (GDF-15), cystatin C and high-sensitivity C-reactive protein (CRP) are independent predictors for incident AF.Blood samples were collected from 883 individuals in the Uppsala Longitudinal Study of Adult Men (ULSAM) and 978 individuals in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. Participants were followed for 10-13years with n=113 incident AF cases in ULSAM and n=148 in PIVUS. The associations between biomarkers and incident AF were analysed in Cox proportional hazards regression models.The hazard ratio (HR) for incident AF was significant for all five biomarkers in unadjusted analyses in both cohorts. Only NT-proBNP remained significant when adjusting for cardiovascular risk factors and the other biomarkers (HR (1SD) 2.05 (1.62-2.59) (ULSAM) and 1.56 (1.30-1.86) (PIVUS), both p0.001). The C-index improved from 0.64 to 0.69 in ULSAM and from 0.62 to 0.68 in PIVUS, by adding NT-proBNP to cardiovascular risk factors (both p0.001). The C-index of the CHARGE-AF risk score increased from 0.62 to 0.68 (ULSAM) and 0.60 to 0.66 (PIVUS) by addition of NT-proBNP (p0.001).Using a multimarker approach NT-proBNP was the strongest predictor of incident AF in two cohorts, and improved risk prediction when added to traditional risk factors. NT-proBNP significantly improved the predictive ability of the novel CHARGE-AF risk score, although the predictive value remained modest.

There is increasing interest in measurement of cardiac troponin (cTn) levels for assessment of subjects from the community. Given the low prevalence of cardiovascular (CV) disease, the utility of cTn as a screening tool in the general population however, is debated. Measurement of cTn levels might instead be clinically useful in selected at-risk cohorts. In fact, several studies have consistently demonstrated that cTn levels in these cohorts are strong predictors of adverse outcome, mainly with respect to mortality and the development of heart failure. cTn levels also provide prognostic value beyond that obtained from standard risk assessment including measurement of other circulating biomarkers and might thus, serve as an important component in primary prevention.