Abstract. Huttunen R, Syrjänen J, Vuento R, Hurme M, Huhtala H, Laine J, Pessi T, Aittoniemi J (Tampere University Hospital; University of Tampere Medical School, University of Tampere; Centre for Laboratory Medicine, Pirkanmaa Hospital District; University of Tampere Medical School; School of Health Sciences, University of Tampere; and Medical School, University of Tampere; Tampere, Finland) Plasma level of soluble urokinase-type plasminogen activator receptor as a predictor of disease severity and case fatality in patients with bacteraemia: a prospective cohort study. J Intern Med 2011; 270: 32-40.Objectives. Urokinase-type plasminogen activator receptor (uPAR) is expressed on a variety of different immune cells and vascular endothelial cells during inflammation. Previous studies indicate that a high plasma concentration of the soluble form of the receptor (suPAR) predicts poor outcome in infectious diseases.Design. A prospective cohort study.Subjects and methods. Plasma suPAR levels were measured in 132 patients with bacteraemia caused by Staphylococcus aureus, Streptococcus pneumoniae, ß-haemolytic streptococcae or Escherichia coli using a commercial enzyme-linked immunosorbent assay (ELISA). Values were measured on days 1-4 after a positive blood culture, on days 13-18 and on recovery.Results. The maximum suPAR values on days 1-4 were markedly higher in nonsurvivors compared to survivors (15.8 vs. 7.3 ng mL , the sensitivity and specificity of suPAR for fatal disease was 83% and 76%, respectively. A high level of suPAR ( ‡11 ng mL ) was associated with hypotension (mean arterial pressure <70 mmHg) (odds ratio (OR) 6.5; 95% CI 2.9-14.6) and high sequential organ failure assessment score ( ‡4) (OR 9.3; 95% CI 4.0-21.9). A high suPAR level remained an independent risk factor for case fatality in a logistic regression model adjusted for potential confounders.Conclusion. Plasma suPAR level is a sensitive and specific independent prognostic biomarker in patients with bacteraemia.

IntroductionRecent studies have shown that apoptosis plays a critical role in the pathogenesis of sepsis. High plasma cell free DNA (cf-DNA) concentrations have been shown to be associated with sepsis outcome. The origin of cf-DNA is unclear.MethodsTotal plasma cf-DNA was quantified directly in plasma and the amplifiable cf-DNA assessed using quantitative PCR in 132 patients with bacteremia caused by Staphylococcus aureus, Streptococcus pneumoniae, ß-hemolytic streptococcae or Escherichia coli. The quality of cf-DNA was analyzed with a DNA Chip assay performed on 8 survivors and 8 nonsurvivors. Values were measured on days 1–4 after positive blood culture, on day 5–17 and on recovery.ResultsThe maximum cf-DNA values on days 1–4 (n = 132) were markedly higher in nonsurvivors compared to survivors (2.03 vs 1.26 ug/ml, p<0.001) and the AUCROC in the prediction of case fatality was 0.81 (95% CI 0.69–0.94). cf-DNA at a cut-off level of 1.52 ug/ml showed 83% sensitivity and 79% specificity for fatal disease. High cf-DNA (>1.52 ug/ml) remained an independent risk factor for case fatality in a logistic regression model. Qualitative analysis of cf-DNA showed that cf-DNA displayed a predominating low-molecular-weight cf-DNA band (150–200 bp) in nonsurvivors, corresponding to the size of the apoptotic nucleosomal DNA. cf-DNA concentration showed a significant positive correlation with visually graded apoptotic band intensity (R = 0.822, p<0.001).ConclusionsPlasma cf-DNA concentration proved to be a specific independent prognostic biomarker in bacteremia. cf-DNA displayed a predominating low-molecular-weight cf-DNA band in nonsurvivors corresponding to the size of apoptotic nucleosomal DNA.

Indoleamine 2,3-dioxygenase (IDO), which is the rate-limiting enzyme for tryptophan (trp) catabolism, may play a critical role in various inflammatory disorders. Recent studies on trauma patients have suggested that the degradation of trp is associated with the development of sepsis. The role of IDO activity in bacteremic patients is unclear. We studied IDO activity in 132 patients with bacteremia caused by Staphylococcus aureus, Streptococcus pneumoniae, beta-hemolytic streptococcae, or Eschericia coli. The serum concentrations of trp and its metabolite kynurenine (kyn) were measured by reverse-phase high-performance liquid chromatography 1 to 4 days after the positive blood culture and on recovery. The kyn-to-trp ratio (kyn/trp), reflecting the activity of the IDO enzyme, was calculated. The maximum value in the ratio for every patient during 1 to 4 days after positive blood culture was used in analysis. The maximum kyn/trp ratio was significantly higher in nonsurvivors versus those who survived (193.7 vs. 82.4 micromol/mmol; P = 0.001). The AUC(ROC) of maximal kyn/trp in the prediction of case fatality was 0.75 (95% confidence interval, 0.64-0.87), and the kyn/trp ratio at a cutoff level of 120 micromol/mmol showed 83% sensitivity and 69% specificity for fatal disease. A kyn/trp ratio greater than 120 micromol/mmol was associated with increased risk of death versus low (

An inappropriate cross-connection between sewage- and drinking-water pipelines contaminated tap water in a Finnish town, resulting in an extensive waterborne gastroenteritis outbreak in this developed country. According to a database and a line-list, altogether 1222 subjects sought medical care as a result of this exposure. Seven pathogens were found in patient samples of those who sought treatment. To establish the true disease burden from this exposure, we undertook a population-based questionnaire investigation with a control population, infrequently used to study waterborne outbreaks. The study covered three areas, contaminated and uncontaminated parts of the town and a control town. An estimated 8453 residents fell ill during the outbreak, the excess number of illnesses being 6501. Attack rates were 53% [95% confidence interval (CI) 49.5-56.4] in the contaminated area, 15.6% (95% CI 13.1-18.5) in the uncontaminated area and 6.5% (95% CI 4.8-8.8) in the control population. Using a control population allowed us to differentiate baseline morbidity from the observed morbidity caused by the water contamination, thus enabling a more accurate estimate of the disease burden of this outbreak.

Background: Bacteraemia is still a major cause of case fatality in all age groups. Our aim was to identify the major underlying conditions constituting risk factors for case fatality in bacteraemia patients.

BackgroundEndocarditis is a common complication in Staphylococcus aureus bacteremia (SAB). We compared risk factors, clinical manifestations, and outcome in a large, prospective cohort of patients with S. aureus endocarditis in injection drug users (IDUs) and in nonaddicts.MethodsFour hundred and thirty consecutive adult patients with SAB were prospectively followed up for 3 months. Definite or possible endocarditis by modified Duke criteria was found in 74 patients: 20 patients were IDUs and 54 nonaddicts.ResultsEndocarditis was more common in SAB among drug abusers (46%) than in nonaddicts (14%) (odds ratio [OR], 5.12; 95% confidence interval [CI], 2.65–9.91; P < 0.001). IDUs were significantly younger (27 ± 15 vs 65 ± 15 years, P < 0.001), had less ultimately or rapidly fatal underlying diseases (0% vs 37%, P < 0.001) or predisposing heart diseases (20% vs 50%, P = 0.03), and their SAB was more often community-acquired (95% vs 39%, P < 0.001). Right-sided endocarditis was observed in 60% of IDUs whereas 93% of nonaddicts had left-sided involvement (P < 0.001). An extracardiac deep infection was found in 85% of IDUs and in 89% of nonaddicts (P = 0.70). Arterial thromboembolic events and severe sepsis were also equally common in both groups. There was no difference in mortality between the groups at 7 days, but at 3 months it was lower among IDUs (10%) compared with nonaddicts (39%) (OR, 5.73; 95% CI, 1.20–27.25; P = 0.02).ConclusionS. aureus endocarditis in IDUs was associated with as high complication rates including extracardiac deep infections, thromboembolic events, or severe sepsis as in nonaddicts. Injection drug abuse in accordance with younger age and lack of underlying diseases were associated with lower mortality, but after adjusting by age and underlying diseases injection drug abuse was not significantly associated with mortality.

IntroductionLong pentraxin 3 (PTX3) is an acute-phase protein secreted by various cells, including leukocytes and endothelial cells. Like C-reactive protein (CRP), it belongs to the pentraxin superfamily. Recent studies indicate that high levels of PTX3 may be associated with mortality in sepsis. The prognostic value of plasma PTX3 in bacteremic patients is unknown.MethodsPlasma PTX3 levels were measured in 132 patients with bacteremia caused by Staphylococcus aureus, Streptococcus pneumoniae, β-hemolytic streptococcae and Escherichia coli, using a commercial solid-phase enzyme-linked immunosorbent assay (ELISA). Values were measured on days 1–4 after positive blood culture, on day 13–18 and on recovery.ResultsThe maximum PTX3 values on days 1–4 were markedly higher in nonsurvivors compared to survivors (44.8 vs 6.4 ng/ml, p<0.001) and the AUCROC in the prediction of case fatality was 0.82 (95% CI 0.73–0.91). PTX3 at a cut-off level of 15 ng/ml showed 72% sensitivity and 81% specificity for fatal disease. High PTX3 (>15 ng/ml) was associated with hypotension (MAP <70 mmHg)(OR 7.9;95% CI 3.3–19.0) and high SOFA score (≥4)(OR 13.2; 95% CI 4.9–35.4). The CRP level (maximum value on days 1 to 4) did not predict case fatality at any cut-off level in the ROC curve (p = 0.132). High PTX3 (>15 ng/ml) remained an independent risk factor for case fatality in a logistic regression model adjusted for potential confounders.ConclusionsPTX3 proved to be a specific independent prognostic biomarker in bacteremia. PTX3 during the first days after diagnosis showed better prognostic value as compared to CRP, a widely used biomarker in clinical settings. PTX3 measurement offers a novel opportunity for the prognostic stratification of bacteremia patients.

The UV dose-response behavior of laboratory cultures of waterborne bacteria were examined for UV doses ranging from ca. 0 -100 mW•s/cm2 using a collimated-beam reactor. Specific physiological responses measured in these tests included viability (ability to reproduce) and respiration (oxygen uptake rate). The results of these exposures indicated that resistance to UV-imposed loss of viability in E. coli cultures can be partially attributed to agglomeration during the irradiation process. From these results, it is conjectured that a bacterial population may be comprised of two sub-populations: one with low resistance (discrete or paired cells) and a second with high resistance (bacterial aggregates). A small fraction of the high-resistance portion of the population appears to be essentially unaffected by UV irradiation, thereby causing a discontinuity in the measured dose-response behavior. Moreover, the dose-response behavior of the highly resistant fraction is variable and difficult to describe quantitatively. The basis of these statements and most information in the literature is microbial viability as quantified by the membrane filtration assay. In contrast to these findings, the results of analyses for bacterial activity (respiration) suggest that comparatively little change in the population can be found to result from UV irradiation. This suggests that UV radiation accomplishes inactivation of the bacteria, but does not “kill” the bacterial cells per se, thereby highlighting the importance of considering bacterial repair processes in the design of UV disinfection systems.