Nausea Predicts Bacteremia in Immunocompetent Patients with Pneumococcal Community-Acquired Pneumonia: Secondary Data Analysis from a Prospective Cohort.

BACKGROUND: In pneumococcal community-acquired pneumonia (CAP), bacteremia is associated with increased mortality, but initial clinical severity scores frequently fail to identify bacteremic patients at risk. We have previously shown that gastrointestinal symptoms are common among patients admitted to the hospital with pneumococcal bacteremia. The aim of this study was to examine gastrointestinal symptoms and inflammatory responses in bacteremic and non-bacteremic pneumococcal CAP in a prospective cohort of immunocompromised and immunocompetent patients hospitalized with CAP. METHODS: Logistic regression analysis was used to estimate the predictive value of gastrointestinal symptoms for pneumococcal bacteremia in patients with CAP. The Mann-Whitney test was used to compare inflammatory responses in patients with bacteremic vs. non-bacteremic pneumococcal CAP. RESULTS: Eighty-one patients with pneumococcal CAP were included, of whom 21 (26%) had bacteremia. Immunocompetent patients with pneumococcal CAP had an odds ratio of 16.5 (95% CI 3.0-90.9, p = 0.001) for bacteremia if nausea was present, whereas no such association was found in the immunocompromised patients (OR 0.22, 95% CI 0.02-2.05, p = 0.18). The serum levels of C-reactive protein, procalcitonin and interleukin 6 were significantly higher in the patients with bacteremic pneumococcal CAP compared to non-bacteremic pneumococcal CAP patients (p < 0.001, p = 0.005, and p = 0.019, respectively). CONCLUSIONS: In immunocompetent patients hospitalized with pneumococcal CAP, nausea may be a predictor of bacteremia. Bacteremic pneumococcal CAP patients display an increased inflammatory response compared to non-bacteremic pneumococcal CAP patients.

Hepcidin predicts 5-year mortality after community-acquired pneumonia.

BACKGROUND: Virtually all living organisms, including microbes and humans, depend on iron to survive and grow. During an infection, the plasma level of iron and several iron-related proteins change substantially. We hypothesized that iron and iron-related proteins could predict short- and long-term outcomes in community-acquired pneumonia. METHODS: Blood samples from a prospective cohort of 267 in-patients with community-acquired pneumonia were analysed for hepcidin, ferritin, iron, transferrin, transferrin saturation, and soluble transferrin receptor at admission and 6-weeks post-discharge. Adverse short-term outcome was defined as admission to intensive care unit or death within 30 days, and long-term outcome was assessed as 5-year overall mortality. Logistic regression, Kaplan Meier survival curves, and Cox regression models with cut-offs at median for the potential biomarkers were used for statistical evaluation. RESULTS: Low admission levels of hepcidin predicted 5-year overall mortality, independently of age, sex, comorbid conditions, and anaemia. Low levels of ferritin at admission as well as low levels of iron and transferrin saturation and high levels of soluble transferrin receptor at the 6-week follow-up were predictors of 5-year overall mortality in univariable, but not in multivariable analyses. Neither of these potential biomarkers predicted adverse short-term outcomes. CONCLUSIONS: In hospitalized patients with community-acquired pneumonia, low levels of hepcidin at admission predicted 5-year overall mortality, but not short-term adverse outcome.

Hepcidin and Ferritin Predict Microbial Etiology in Community-Acquired Pneumonia.

BACKGROUND: Iron is crucial for survival and growth of microbes. Consequently, limiting iron availability is a human antimicrobial defense mechanism. We explored iron and iron-related proteins as potential biomarkers in community-acquired pneumonia and hypothesized that infection-induced changes in these potential biomarkers differ between groups of pathogens and could predict microbial etiology. METHODS: Blood samples from a prospective cohort of 267 patients with community-acquired pneumonia were analyzed for hepcidin, ferritin, iron, transferrin, and soluble transferrin receptor at admission, clinical stabilization, and a 6-week follow-up. A total of 111 patients with an established microbiological diagnosis confined to 1 microbial group (atypical bacterial, typical bacterial, or viral) were included in predictive analyses. RESULTS: High admission levels of ferritin predicted atypical bacterial versus typical bacterial etiology (odds ratio [OR], 2.26; 95% confidence interval [CI], 1.18-4.32; P = .014). Furthermore, hepcidin and ferritin predicted atypical bacterial versus viral etiology (hepcidin: OR = 3.12, 95% CI = 1.34-7.28, P = .008; ferritin: OR = 2.38, 95% CI = 1.28-4.45, P = .006). The findings were independent of C-reactive protein and procalcitonin. CONCLUSIONS: Hepcidin and ferritin are potential biomarkers of microbial etiology in community-acquired pneumonia.