High pneumococcal DNA load, procalcitonin and suPAR levels correlate to severe disease development in patients with pneumococcal pneumonia.

Community-acquired pneumonia (CAP) is mostly caused by Streptococcus pneumoniae. Identification of the pathogen causing CAP can be achieved by conventional culture techniques of sputum and/or blood, antigen detection from urine or molecular analysis. However, it remains difficult to determine patients who are at risk of severe disease development (intensive care unit [ICU] admittance and/or death). In this retrospective study, 121 patients admitted to the emergency department with pneumonia symptoms were included. Several markers of infection (pneumococcal DNA load in blood (real-time LytA PCR), white blood cell (WBC) count, C-reactive protein (CRP), procalcitonin (PCT) and soluble urokinase plasminogen activator receptor (suPAR) levels) were assessed for their ability to predict severe disease development. Of 121 patients, 6 were excluded from the study because of an alternative diagnosis, whereas 8 were excluded from biomarker analysis because of the presence of co-morbidities. Of the 115 patients analysed by the LytA PCR, 23 were positive. PCR detected S. pneumoniae DNA in 82% of patients with positive blood culture for S. pneumoniae. PCR missed three samples from patients in which S. pneumoniae was recovered by blood cultures. However, eight additional LytA PCR-positive samples were detected from patients whose blood cultures remained negative. Pneumococcal DNA load was also monitored in time for 31 patients, of whom 11 had positive PCR results. For 10 out of 11 (91%) positive PCR patients, a clear increase in Ct-values was observed, indicating a lower pneumococcal DNA load in the blood as a result of antibiotic therapy. Biomarker analysis was performed in 107 patients, of whom 29 showed severe disease development. Pneumococcal DNA load (p = 0.026), PCT (p = 0.046) and suPAR (p = 0.001) levels most reliably predicted severe disease development. In conclusion, in patients with CAP, higher pneumococcal DNA load, PCT and suPAR values are associated with severe disease development (ICU admission and/or death). These biomarkers may be useful tools for triage of patients suspected of having CAP in the emergency department.

Value of 18F-FDG PET/CT in diagnosing chronic Q fever in patients with central vascular disease.

BACKGROUND: The aim of this study is to describe the value of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in diagnosing chronic Q fever in patients with central vascular disease and the added value of 18F-FDG PET/CT in the diagnostic combination strategy as described in the Dutch consensus guideline for diagnosing chronic Q fever. METHODS: 18F-FDG PET/CT was performed in patients with an abdominal aortic aneurysm or aorto-iliac reconstruction and chronic Q fever, diagnosed by serology and positive PCR for Coxiella burnetii DNA in blood and/or tissue (PCR-positive study group). Patients with an abdominal aortic aneurysm or aorto-iliac reconstruction without clinical and serological findings indicating Q fever infection served as a control group. Patients with a serological profile of chronic Q fever and a negative PCR in blood were included in additional analyses (PCR-negative study group). RESULTS: Thirteen patients were evaluated in the PCR-positive study group and 22 patients in the control group. 18F-FDG PET/CT indicated vascular infection in 6/13 patients in the PCR-positive study group and 2/22 patients in the control group. 18F-FDG PET/CT demonstrated a sensitivity of 46% (95% CI: 23-71%), specificity of 91% (95% CI: 71-99%), positive predictive value of 75% (95% CI:41-93%) and negative predictive value of 74% (95% CI: 55-87%). In the PCR-negative study group, 18F-FDG PET/CT was positive in 10/20 patients (50%). CONCLUSION: The combination of 18F-FDG PET/CT, as an imaging tool for identifying a focus of infection, and Q fever serology is a valid diagnostic strategy for diagnosing chronic Q fever in patients with central vascular disease.

A non-invasive cardiac output measurement as an alternative to the test bolus technique during CT angiography.

AIM: To investigate the association between a non-invasive cardiac output (CO) measurement and the scan delay, as derived from a test bolus injection protocol. The secondary objective was to determine which factors affect the relationship between the CO and scan delay. MATERIALS AND METHODS: Fifty-five patients referred for a contrast-enhanced (thorax-)abdomen CT examination were included in this feasibility study. A test bolus examination was performed prior to the abdominal CT. During the test bolus injection, the CO of the patient was measured using a non-invasive finger-cuff measurement. Associations were analysed using linear regression analyses. Age, gender, height, weight, and blood pressure were included as potential confounders. RESULTS: Linear regression analysis showed a negative and significant association between CO and delay. The regression formula was as follows: scan delay (seconds) = 26.8-1.6 CO (l/min), with a 95% CI between -2.3 and -1.0 (p<0.001). Weight appeared to be a confounder in this relation, and gender and blood pressure were effect modifiers. There was no interaction between scan delay and age, height and weight. CONCLUSIONS: There is a negative and significant association between the non-invasive CO measurement and the CT scan delay; however, to validate these findings a larger cohort study is needed to investigate whether the non-invasively determined scan delay is as accurate as the use of a test bolus.

Vascular chronic Q fever: quality of life.

The aim of this study was to evaluate the quality of life in patients with vascular chronic Q fever at time of diagnosis and during follow-up. Based upon the SF-36 questionnaire, the mean physical and mental health of each patient were assessed at 3-month intervals for up to 18 months. A total of 26 patients were included in the study. At time of diagnosis, the mean physical health and mental health score was 50·6 [95% confidence interval (CI) 46·7-54·4] and 44·6 (95% CI 41·6-47·5), respectively. During treatment, the mean physical health score declined significantly by 1·7 points each 3 months (P < 0·001) to 40·8 (95% CI 34·4-45·1). The mean mental health score significantly and steadily increased towards 51·2 (95% CI 46·9-54·3) during follow-up (P = 0·026). A total of 23% of patients were cured after 18 months of follow-up. In conclusion, quality of life at time of diagnosis for patients with vascular chronic Q fever is lower compared to a similar group of patients, matched for age and gender, with an aortic abdominal aneurysmal disease, and physical health decreases further after starting treatment. Considering the low percentage of cure, the current treatment of vascular chronic Q fever patients may require a separate strategy from that of endocarditis in order to increase survival.