Jasmin Wagner

Performance of Galactomannan, Beta-d-Glucan, Aspergillus Lateral-Flow Device, Conventional Culture, and PCR Tests with Bronchoalveolar Lavage Fluid for Diagnosis of Invasive Pulmonary Aspergillosis

ABSTRACT Galactomannan detection in bronchoalveolar lavage (BAL) fluid samples (GM test) is currently considered the gold standard test for diagnosing invasive pulmonary aspergillosis (IPA). The limitations, however, are the various turnaround times and availability of testing. We compared the performance of GM testing with that of conventional culture, an Aspergillus lateral-flow-device (LFD) test, a beta-d-glucan (BDG) test, and an Aspergillus PCR assay by using BAL fluid samples from immunocompromised patients. A total of 78 BAL fluid samples from 78 patients at risk for IPA (74 samples from Graz and 4 from Mannheim) collected between December 2012 and May 2013 at two university hospitals in Austria and Germany were included. Three patients had proven IPA, 14 probable IPA, and 17 possible IPA, and 44 patients had no IPA. The diagnostic accuracies of the different methods for probable/proven IPA were evaluated. The diagnostic odds ratios were the highest for the GM, PCR, and LFD tests. The sensitivities for the four methods (except culture) were between 70 and 88%. The combination of the GM (cutoff optical density index [ODI], >1.0) and LFD tests increased the sensitivity to 94%, while the combination of the GM test (>1.0) and PCR resulted in 100% sensitivity (specificity for probable/proven IPA, 95 to 98%). The performance of conventional culture was limited by low sensitivity, while that of the BDG test was limited by low specificity. We evaluated established and novel diagnostic methods for IPA and found that the Aspergillus PCR, LFD, and GM tests were the most useful methods for diagnosing the disease by using BAL fluid samples. In particular, the combination of the GM test and PCR or, if PCR is not available, the LFD test, allows for sensitive and specific diagnosis of IPA.

Diagnostic accuracy of soluble urokinase plasminogen activator receptor (suPAR) for prediction of bacteremia in patients with systemic inflammatory response syndrome.

OBJECTIVES Soluble urokinase plasminogen activator receptor (suPAR) serum concentrations have recently been described to reflect the severity status of systemic inflammation. In this study, the diagnostic accuracy of suPAR, C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) to predict bacteremia in patients with systemic inflammatory response syndrome (SIRS) was compared. METHODS A total of 132 patients with SIRS were included. In 55 patients blood cultures had resulted positive (study group 1, Gram positive bacteria: Staphylococcus aureus and Streptococcus spp., n=15; study group 2, Gram-negative bacteria, n=40) and 77 patients had negative blood culture results (control group, n=77). Simultaneously with blood cultures suPAR, CRP, PCT, IL-6 and white blood count (WBC) were determined. RESULTS SuPAR values were significantly higher in study group 1 (median 8.11; IQR 5.78-15.53; p=0.006) and study group 2 (median 9.62; IQR 6.52-11.74; p<0.001) when compared with the control group (median 5.65; IQR 4.30-7.83). ROC curve analysis revealed an AUC of 0.726 for suPAR in differentiating SIRS patients with bacteremia from those without. The biomarkers PCT and IL-6 showed comparable results. Regarding combinations of biomarkers multiplying suPAR, PCT and IL-6 was most promising and resulted in an AUC value of 0.804. Initial suPAR serum concentrations were significantly higher (p=0.028) in patients who died within 28 days than in those who survived. No significant difference was seen for PCT, IL-6 and CRP. CONCLUSION In conclusion, suPAR, IL-6 and PCT may contribute to predicting bacteremia in SIRS patients.

Potential Factors for Inadequate Voriconazole Plasma Concentrations in Intensive Care Unit Patients and Patients with Hematological Malignancies

ABSTRACT Voriconazole plasma concentrations (VPCs) vary widely, and concentrations outside the therapeutic range are associated with either worse outcome in invasive aspergillosis (IA) or increased toxicity. The primary goal of this cohort study conducted in a real-life setting was to identify potential factors associated with inadequate VPCs in ICU patients and patients with hematological malignancies. Within a period of 12 months, trough VPCs were obtained and analyzed with high-performance liquid chromatography, and the adequate range was defined as 1.5 to 5.5 mg/liter. VPCs of <1.5 mg/liter were defined as low, whereas VPCs of >5.5 mg/liter were defined as potentially toxic. A total of 221 trough VPCs were obtained in 61 patients receiving voriconazole, and 124/221 VPCs (56%) were found to be low. Multivariate analysis revealed that low VPCs were significantly associated with clinical failure of voriconazole, prophylactic use, younger age, underlying hematological malignancy, concomitant proton pump inhibitor (PPI) (pantoprazole was used in 88% of the patients), and absence of side effects. Low VPCs remained an independent predictor of clinical failure of voriconazole. The defined adequate range was reached in 79/221 (36%) VPCs. In 18 samples (8%), potentially toxic levels were measured. Multivariate analysis revealed higher body mass index (BMI), absence of hematological malignancy, therapeutic application, and diarrhea as factors associated with potentially toxic VPCs. Neurotoxic adverse events occurred in six patients and were mostly associated with VPCs in the upper quartile of our defined adequate range. In conclusion, potential factors like younger age, prophylaxis, underlying hematological malignancy, BMI, and concomitant PPI should be considered within the algorithm of voriconazole treatment.

Feasibility of testing three salivary stress biomarkers in relation to naturalistic traffic noise exposure.

BACKGROUND AND OBJECTIVES Stress dependent alterations of the salivary biomarkers alpha-amylase (sAA), salivary chromogranin A (sCgA) and salivary cortisol (sC) have been reported in numerous studies recently. The aim of this pilot study was to investigate the feasibility of testing sAA, sCgA and sC in relation to naturalistic traffic noise exposure in order to monitor a direct stress response in a laboratory setup. METHODS A total of twenty study participants were exposed to binaurally recorded naturalistic traffic noise samples containing 75 dB (L(A,)eq) for 20 minutes via a loudspeaker system. Saliva was collected directly before and after defined exposure to naturalistic traffic noise. Determination of sAA was performed enzymatically on a Hitachi 912 laboratory analyzer, sCgA was determined by ELISA technique and sC was determined using a RIA assay. RESULTS AND CONCLUSIONS There was a significant increase of sAA and sC concentrations after traffic noise exposure (p=0.045; p=0.01), whereas for sCgA this was not observed (p=0.48). Measuring of sAA and sC appear to be feasible to investigate direct stress effects in relation to naturalistic traffic noise exposure in a laboratory setup. Considering the small sample size of this pilot study, these observations need to be further proved in a larger explorative study.

Automation of serum (1→3)-beta-D-glucan testing allows reliable and rapid discrimination of patients with and without candidemia

Testing for (1→3)-beta-D-glucan (BDG) is used for detection of invasive fungal infection. However, current assays lack automation and the ability to conduct rapid single-sample testing. The Fungitell assay was adopted for automation and evaluated using clinical samples from patients with culture-proven candidemia and from culture-negative controls in duplicate. A comparison with the standard assay protocol was made in order to establish analytical specifications. With the automated protocol, the analytical measuring range was 8-2500 pg/ml of BDG, and precision testing resulted in coefficients of variation that ranged from 3.0% to 5.5%. Samples from 15 patients with culture-proven candidemia and 94 culture-negative samples were evaluated. All culture-proven samples showed BDG values >80 pg/ml (mean 1247 pg/ml; range, 116-2990 pg/ml), which were considered positive. Of the 94 culture-negative samples, 92 had BDG values <60 pg/ml (mean, 28 pg/ml), which were considered to be negative, and 2 samples were false-positive (≥80 pg/ml; up to 124 pg/ml). Results could be obtained within 45 min and showed excellent agreement with results obtained with the standard assay protocol. The automated Fungitell assay proved to be reliable and rapid for diagnosis of candidemia. It was demonstrated to be feasible and cost efficient for both single-sample and large-scale testing of serum BDG. Its 1-h time-to-result will allow better support for clinicians in the management of antifungal therapy.

Soluble urokinase plasminogen activator receptor predicts mortality in patients with systemic inflammatory response syndrome

The soluble urokinase plasminogen activator receptor (suPAR) reflects inflammation. However, the prognostic value of suPAR measurements, particularly at the very early onset of systemic inflammatory response syndrome (SIRS), is less well defined.

Sensitivity of galactomannan enzyme immunoassay for diagnosing breakthrough invasive aspergillosis under antifungal prophylaxis and empirical therapy

Data on diagnostic performance of Galactomannan (GM) testing in patients under mould‐active regimens are limited. Whether sensitivity of GM testing for diagnosing breakthrough invasive aspergillosis (IA) is decreased under antifungal prophylaxis/therapy remains therefore a point of discussion. We retrospectively analysed GM test results in patients who were admitted with underlying haematological malignancies to two Divisions of the Medical University Hospital of Graz, Austria, between 2009 and 2012. Only cases of probable and proven IA that were diagnosed by other methods than GM testing were included (time of diagnosis = day 0). We compared GM results of patients with/without therapy/prophylaxis for the period of 2 weeks prior (week −2) until 3 weeks postdiagnosis. A total of 76 GM test results in nine patients were identified. Six patients had received antifungal therapy/prophylaxis from week −2, whereas three patients were treated with therapy from the time of diagnosis at week 0. GM testing was positive in 45/76 (59%) of samples. Sensitivity of GM testing for detection of proven or probable IA at week −1 and 0 was 77% and 79% in patients with mould‐active regimens. We conclude that GM testing might be a useful diagnostic method for breakthrough IA in patients receiving mould‐active prophylaxis/therapy.

Characteristics of Hospital-Acquired and Community-Onset Blood Stream Infections, South-East Austria

Purpose The objective of this study was to compare epidemiology, causative pathogens, outcome, and levels of laboratory markers of inflammation of community-onset (i.e. community-acquired and healthcare-associated) and hospital-acquired bloodstream infection (BSI) in South-East Austria. Methods In this prospective cohort study, 672 patients fulfilling criteria of systemic inflammatory response syndrome with positive peripheral blood cultures (277 community-onset [192 community-acquired, 85 healthcare-associated BSI], 395 hospital-acquired) were enrolled at the Medical University of Graz, Austria from 2011 throughout 2012. Clinical, microbiological, demographic as well as outcome and laboratory data was collected. Results Escherichia coli followed by Staphylococcus aureus were the most frequently isolated pathogens. While Streptococcus spp. and Escherichia coli were isolated more frequently in patients with community-onset BSI, Enterococcus spp., Candida spp., Pseudomonas spp., Enterobacter spp., and coagulase-negative staphylococci were isolated more frequently among those with hospital-acquired BSI. With regard to the outcome, 30-day (82/395 vs. 31/277; p = 0.001) and 90-day mortality (106/395 vs. 35/277; p<0.001) was significantly higher among patients with hospital-acquired BSI even though these patients were significantly younger. Also, hospital-acquired BSI remained a significant predictor of mortality in multivariable analysis. At the time the blood cultures were drawn, patients with community-onset BSI had significantly higher leukocyte counts, neutrophil-leucocyte ratios as well as C-reactive protein, procalcitonin, interleukin-6 and serum creatinine levels when compared to those with hospital-acquired BSI. Patients with healthcare-associated BSI presented with significantly higher PCT and creatinine levels than those with community-acquired BSI. Conclusions Hospital-acquired BSI was associated with significantly higher 30- and 90-day mortality rates. Hospital-acquired BSI therefore poses an important target for the most aggressive strategies for prevention and infection control.

Procalcitonin fails to predict bacteremia in SIRS patients: a cohort study

Procalcitonin (PCT) has previously been proposed as useful marker to rule out bloodstream‐infection (BSI). The objective of this study was to evaluate the sensitivity of different PCT cut‐offs for prediction of BSI in patients with community (CA)‐ and hospital‐acquired (HA)‐BSI.

Reliable Detection and Quantitation of Viral Nucleic Acids in Oral Fluid : Liquid Phase-Based Sample Collection in Conjunction With Automated and Standardized Molecular Assays

Oral fluid has been used widely as sample matrix for the detection and quantitation of viral nucleic acids. However, in the vast majority of previous studies, various methods for collection of oral fluid and molecular assays lacking automation and standardization were used. In this study, a new standardized liquid phase‐based saliva collection system was employed followed by a fully automated viral nucleic acid extraction and real‐time PCR using commercially available in vitro diagnostics (IVD)/Conformité Européene (CE) labeled molecular assays. When the lower limit of detection of herpes simplex virus (HSV)‐1/2 DNA, varicella zoster virus (VZV) DNA, and hepatitis C virus (HCV) RNA in spiked oral fluid was tested, the results were found to be comparable to those with defined sample materials recommended by the assay manufacturers. When clinical specimens were investigated, 21 of 25 (84%) oral fluids obtained from patients with clinically apparent herpetic lesions tested positive for HSV DNA, 7 of 10 (70%) oral fluids obtained from patients with Ramsay Hunt Syndrome tested positive for VZV DNA, and 19 of 40 (48%) oral fluids collected from patients with chronic HCV infection tested positive for HCV RNA. The automated extraction instruments completed all extractions without malfunction and no inhibitions were observed throughout the entire study. Liquid phase‐based saliva collection in conjunction with automated and standardized commercially available molecular assays allows reliable quantitation of viral nucleic acids in oral fluid samples and may contribute to improved comparable and interpretable test results. J. Med. Virol. 80:1684–1688, 2008.