Jasmin Rabensteiner

Galactomannan testing and Aspergillus PCR in same-day bronchoalveolar lavage and blood samples for diagnosis of invasive aspergillosis

&NA; In recent years galactomannan antigen testing (GM) and also Aspergillus PCR have become increasingly important for diagnosis of invasive aspergillosis (IA). Whether or not these tests need to be performed with bronchoalveolar lavage fluid (BALF; i.e., primary site of infection), or testing of blood samples is sufficient, remains, however, a matter of debate. We evaluated the diagnostic performance of GM ELISA, and Aspergillus PCR by using BALF samples and blood samples obtained at the same day from a total of 53 immunocompromised patients (16 with probable/proven IA and 37 with no evidence of IA according to the revised EORTC/MSG criteria; 38 patients with hematological malignancies were prospectively enrolled at the Medical University of Graz, Austria, 15 patients with mixed underlying diseases at the Mannheim University Hospital). Patients with possible IA were excluded from this analysis. A total of 34/53 (64%) of all patients and 12/16 (75%) of patients with probable/proven IA received mold‐active antifungal prophylaxis/therapy at the time of the BALF procedure. Sensitivities of GM and Aspergillus PCR were 38% and 44% in BALF, and 31% and 0% in blood, respectively. Best sensitivity (75%) for detecting proven/probable IA was achieved when BALF Aspergillus PCR, BALF GM (>1.0 ODI), BALF‐culture and serum‐GM (>0.5 ODI) were combined (specificity 95%). In conclusion, sensitivities of the evaluated diagnostic tests—when interpreted on their own—were low in BALF and even lower in blood, sensitivities increased markedly when diagnostic tests were combined.

Serum 1,3-beta-d-glucan for antifungal treatment stratification at the intensive care unit and the influence of surgery

The purpose of this study was to evaluate a preemptive approach with serum 1,3‐beta‐d‐glucan (BDG) as a marker for treatment stratification of systemic antifungal (AF) therapy in patients with clinical suspected invasive fungal infections (IFI) at intensive care units (ICU), and the impact of surgical procedures. A total of 66 ICU patients with clinical suspected IFI were included in this retrospective analysis. Serum BDG testing was performed prior to initiation of AF treatment and in addition to routine diagnostic measures. Based on the BDG results the initial clinical decision whether or not to start systemic AF therapy was re‐evaluated. Impact of surgical procedures on clinical utility of serum BDG was evaluated in a sub‐group of 25 patients who had undergone surgical procedures prior to BDG evaluation. BDG test results led to discontinuation of AF therapy in 13 patients, and initiation of AF therapy in seven patients. In 46 patients the clinical decision was confirmed by BDG. The majority of suspected, probable and proven IFI cases (10/13, 77%) was predicted by the test. BDG testing turned out positive in 9/25 (36%) of patients that had undergone recent surgery and levels correlated with clinical findings. Serum BDG evaluation seems to be a promising tool to guide AF therapy in ICU patients even after recent surgical procedures.

Characterisation of Candida within the Mycobiome/Microbiome of the Lower Respiratory Tract of ICU Patients

Whether the presence of Candida spp. in lower respiratory tract (LRT) secretions is a marker of underlying disease, intensive care unit (ICU) treatment and antibiotic therapy or contributes to poor clinical outcome is unclear. We investigated healthy controls, patients with proposed risk factors for Candida growth in LRT (antibiotic therapy, ICU treatment with and without antibiotic therapy), ICU patients with pneumonia and antibiotic therapy and candidemic patients (for comparison of truly invasive and colonizing Candida spp.). Fungal patterns were determined by conventional culture based microbiology combined with molecular approaches (next generation sequencing, multilocus sequence typing) for description of fungal and concommitant bacterial microbiota in LRT, and host and fungal biomarkes were investigated. Admission to and treatment on ICUs shifted LRT fungal microbiota to Candida spp. dominated fungal profiles but antibiotic therapy did not. Compared to controls, Candida was part of fungal microbiota in LRT of ICU patients without pneumonia with and without antibiotic therapy (63% and 50% of total fungal genera) and of ICU patients with pneumonia with antibiotic therapy (73%) (p<0.05). No case of invasive candidiasis originating from Candida in the LRT was detected. There was no common bacterial microbiota profile associated or dissociated with Candida spp. in LRT. Colonizing and invasive Candida strains (from candidemic patients) did not match to certain clades withdrawing the presence of a particular pathogenic and invasive clade. The presence of Candida spp. in the LRT rather reflected rapidly occurring LRT dysbiosis driven by ICU related factors than was associated with invasive candidiasis.

Chemotherapy-Induced Intestinal Mucosal Barrier Damage: a Cause of Falsely Elevated Serum 1,3-Beta-d-Glucan Levels?

ABSTRACT Blood citrulline and intestinal fatty acid binding protein were determined as biomarkers for intestinal mucositis. Biomarker levels were correlated with corresponding serum 1,3-beta-d-glucan levels in 56 samples obtained from 33 cases with underlying hematological malignancies receiving induction chemotherapy. No correlation between biomarkers of intestinal mucositis and BDG levels was observed. (This study has been registered at ClinicalTrials.gov under registration no. NCT01576653.)

Elevated Levels of Interleukin 17A and Kynurenine in Candidemic Patients, Compared With Levels in Noncandidemic Patients in the Intensive Care Unit and Those in Healthy Controls

BACKGROUND The interplay between Candida species and pattern recognition receptors, interleukins, kynurenine, and T cells has been studied in murine and ex vivo human studies, but data are lacking from patients with invasive fungal infections. Interleukin 17A (IL-17A) is considered an important component in host defense against Candida infections and is modulated by Candida-induced impairment of tryptophan-kynurenine metabolism. METHODS Dectin-1, Toll-like receptor 2, and Toll-like receptor 4 expression; regulatory T cell (Treg) percentages; and interleukin 6, interleukin 10, IL-17A, interleukin 22, interleukin 23, interferon γ, kynurenine, and tryptophan levels were determined in candidemic patients and compared to levels in noncandidemic patients who are in the intensive care unit (ICU) and receiving antibiotic therapy and those in healthy controls, both with and without Candida colonization. RESULTS Candidemic patients had significantly higher IL-17A and kynurenine levels, compared with noncandidemic patients, including Candida-colonized ICU patients and healthy controls. Within candidemic patients, time-dependent elevation of IL-17A and kynurenine levels was detected. IL-17A areas under the curve for differentiation between patients with early candidemia and those without candidemia (ICU patients, including Candida-colonized patients, and healthy controls) were between 0.94 (95% confidence interval [CI], .89-.99) and 0.99 (95% CI, .99-1). CONCLUSIONS Candidemic patients had significantly higher IL-17A and kynurenine levels, compared with noncandidemic patients. The statistically significant association between IL-17A and kynurenine levels and candidemia suggests their potential as biomarkers for anticipation of invasive candidiasis. CLINICAL TRIALS REGISTRATION NCT00786903.

Detection of (1→3)‐β‐D‐glucan in same‐day urine and serum samples obtained from patients with haematological malignancies

Serum 1,3‐beta‐d‐glucan (BDG) testing is an established diagnostic marker for invasive fungal infections (IFI) among patients with haematological malignancies. In contrast limited data exist regarding the application of urine BDG testing. Same‐day midstream urine and serum screening samples were collected in adult patients with underlying haematological malignancies. A total of 80 urine samples from 46 patients were investigated: Twenty‐six had positive corresponding serum BDG >120 pg ml−1, 27 intermediate (60–80 pg ml−1), and 27 negative serum BDG (<25 pg ml−1). A significant positive correlation between BDG in serum and urine samples was observed (P = 0.025; r = 0.252). Sensitivity, specificity, positive predictive value and negative predictive value (compared with same‐day serum results) were: 42%, 76%, 46%, 73% when using an 80 pg ml−1 urine cut‐off, and 35%, 96%, 82%, 75% for a 250 pg ml−1 cut‐off. Urine BDG seemed to be higher in samples obtained from patients with probable IFI (n = 13, median 145, IQR 22–253) compared to those from patients without IFI (n = 56, median 24, IQR 15–88) but the difference was not significant (P = 0.069). Overall correlation of same‐day urine BDG and serum BDG was moderate. However, urine BDG testing may warrant further investigation in larger studies, as high‐positive urine results correlated with high‐positive corresponding serum levels and clinical performance was comparable to serum BDG.

Levels of interleukin (IL)-6 and IL-8 are elevated in serum and bronchoalveolar lavage fluid of haematological patients with invasive pulmonary aspergillosis

Aspergillus spp. have been shown to induce T‐helper cell (Th) 1 and Th17 subsets resulting in elevated levels of several cytokines. The objective of this study was to analyse a bundle of cytokines in serum and bronchoalveolar lavage fluid (BALF) in patients with and without invasive pulmonary aspergillosis (IPA). This nested case‐control analysis included 10 patients with probable/proven IPA and 20 matched controls without evidence of IPA, out of a pool of prospectively enrolled (2014‐2017) adult cases with underlying haematological malignancies and suspected pulmonary infection. Serum samples were collected within 24 hours of BALF sampling. All samples were stored at −70°C for retrospective determination of cytokines. IL‐6 and IL‐8 were significantly associated with IPA in both serum (P = .011 and P = .028) and BALF (P = .006 and P = .012, respectively), and a trend was observed for serum IL‐10 (P = .059). In multivariate conditional logistic regression analysis, IL‐10 remained a significant predictor of IPA in serum and IL‐8 among BALF cytokines. In conclusion, levels of IL‐6 and IL‐8 were significantly associated with probable/proven IPA, and a similar trend was observed for serum IL‐10. Future cohort studies should determine the diagnostic potential of these cytokines for IPA, and evaluate combinations with other IPA biomarkers/diagnostic tests.

Diagnosis of invasive aspergillosis in hematological malignancy patients: Performance of cytokines, Asp LFD, and Aspergillus PCR in same day blood and bronchoalveolar lavage samples

BACKGROUND Aspergillus spp. induce elevated levels of several cytokines. It remains unknown whether these cytokines hold value for clinical routine and enhance diagnostic performances of established and novel biomarkers/tests for invasive aspergillosis (IA). METHODS This cohort study included 106 prospectively enrolled (2014-2017) adult cases with underlying hematological malignancies and suspected pulmonary infection undergoing bronchoscopy. Serum samples were collected within 24 hours of bronchoalveolar lavage fluid (BALF) sampling. Both, serum and BALF samples were used to evaluate diagnostic performances of the Aspergillus-specific lateral-flow device test (LFD), Aspergillus PCR, β-D-glucan, and cytokines that have shown significant associations with IA before. RESULTS Among 106 cases, 11 had probable IA, and 32 possible IA; 80% received mold-active antifungals at the time of sampling. Diagnostic tests and biomarkers showed better performance in BALF versus blood, with the exception of serum interleukin (IL)-8 which was the most reliable blood biomarker. Combinations of serum IL-8 with either BALF LFD (sensitivity 100%, specificity 94%) or BALF PCR (sensitivity 91%, specificity 97%) showed promise for differentiating probable IA from no IA. CONCLUSIONS High serum IL-8 levels were highly specific, and when combined with either the BALF Aspergillus-specific LFD, or BALF Aspergillus PCR also highly sensitive for diagnosis of IA.

Prognostic and diagnostic potential of suPAR levels in pleural effusion

Recently, Birkenkamp et al. highlighted the need for further studies defining the optimal management of patients with pleural empyema including accurate diagnostic work up of pleural effusions. Soluble urokinase plasminogen activator receptor (suPAR) is the soluble form of urokinase plasminogen activator receptor (uPAR), a receptor, which is expressed on different cells, in particular macrophages, lymphocytes, neutrophils, vascular endothelial and malignant cells. Plasma suPAR levels have been evaluated for early detection of bacteraemia, progression of chronic kidney diseases, as predictor for sepsis severity and for prediction of mortality in various patients’ cohorts. Raggam and colleagues have previously shown in a large cohort that plasma levels of suPAR predict short term, 30and 90-day mortality among patients with systemic inflammatory response syndrome. SuPAR levels can also be detected in pleural effusion (PE) and may have diagnostic potential in differentiating non-cardiac pleural effusions from cardiac pleural effusions. Studies confirming the diagnostic potential and evaluating prognostic value of PE suPAR levels, however, are missing. We evaluated the prognostic value of suPAR regarding 48-hour, 30-day and 90-day mortality in PE and investigated whether PE suPAR levels may be useful for distinguishing different types of PE. A total of 134 consecutive PE samples

Road and rail traffic noise induce comparable extra-aural effects as revealed during a short-term memory test.

To examine extraaural effects as induced by 20 min of road (ROAD) and 20 min of rail (RAIL) traffic noise with same loudness (75 dBA), a laboratory study was carried out. The study (N = 54) consisted of 28 high and 26 low-annoyed healthy individuals as determined by a traffic annoyance test. To control attention, all individuals performed a nonauditory short-term memory test during the noise exposures. A within-subject design, with phases of ROAD, RAIL, and CALM (memory test only), alternated by phases of rest, was defined. Heart rate (HR), systolic blood pressure (sBP), total peripheral resistance (TPR), as well as three autonomic variables, preejection period (PEP), 0.15–0.4 Hz high-frequency component of HR variability (HF), and salivary stress biomarker alpha amylase (sAA) were measured. In relation to CALM, HR increased (RAIL +2.1%, ROAD +2.5%), sBP tended to increase against the end of noise exposure, PEP decreased (RAIL −0.7%, ROAD −0.8%), HF decreased (RAIL −3.4%, ROAD −2.9%), and sAA increased (RAIL +78%, ROAD +69%). No differences were found between RAIL and ROAD, indicating that both noise stressors induced comparable extraaural effects. Factor annoyance showed significant during CALM. Here a reduced sympathetic drive (higher PEP values) combined with an increased vascular tone (higher TPR values) was found at the high-annoyed subgroup.