Christoph Koidl

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.

Bioavailability and Pharmacokinetics of Alkamides From the Roots of Echinacea angustifolia in Humans

Alkamides are suspected to contribute to the activity of Echinacea preparations. They are mainly derived from undeca‐ and dodecanoic acid and differ in the degree of unsaturation and the configuration of the double bonds. In total, 6 alkamides have been isolated from the roots of Echinacea angustifolia as major lipophilic constituents and have been investigated regarding their pharmacokinetics. A sensitive and specific method has been developed for the identification and quantification of these alkamides in human plasma using liquid chromatography electrospray ionization ion‐trap mass spectrometry. The method was applied to analyze plasma samples obtained from a randomized, open, single‐dose, crossover study after oral administration of a 60% ethanolic extract from the roots of E. angustifolia to 11 healthy subjects. The maximum concentration of dodeca‐2E,4E,8Z,10E/Z‐tetraenoic acid isobutylamides, the main alkamides in the roots of E. angustifolia, appeared already after 30 minutes and was 10.88 ng/mL for the 2.5‐mL dose.

Novel Tests for Diagnosis of Invasive Aspergillosis in Patients with Underlying Respiratory Diseases

RATIONALE Invasive pulmonary aspergillosis has been increasingly reported in nonneutropenic patients, including those with underlying respiratory diseases. OBJECTIVES We compared the diagnostic performances of galactomannan, 1,3-β-D-glucan, and Aspergillus-specific lateral-flow device tests with that of conventional culture by using bronchoalveolar lavage fluid samples from patients with underlying respiratory diseases. METHODS We analyzed 268 bronchoalveolar lavage samples from 221 patients with underlying respiratory diseases (and without hematologic malignancy or previous solid organ transplantation) that were collected for routine microbiological workup between February 2012 and May 2014 at the University Hospital of Graz, Austria. Invasive pulmonary aspergillosis was defined according to European Organization of Research and Treatment of Cancer/Mycoses Study Group criteria modified for patients with respiratory diseases. MEASUREMENTS AND MAIN RESULTS Thirty-one patients (14%) had probable or proven, 25 possible, and the remaining 165 patients no invasive pulmonary aspergillosis. Probable/proven aspergillosis was associated with a significantly higher (P = 0.034) 30-day mortality rate of 32%. Sensitivities, specificities, and diagnostic odd ratios differed markedly between galactomannan (cut-off 0.5: optical density index, 0.97, 0.81, 124.4; cut-off 1.0: 0.97, 0.93, 422.1; cut-off 3.0: 0.61, 0.99, 109.8), β-D-glucan (cut-off 80 pg/ml: 0.90, 0.42, 6.57; cut-off 200 pg/ml: 0.70, 0.61, 3.7), lateral-flow device tests (0.77, 0.92, 41.8), and mycological culture (0.29, 0.97, 14). CONCLUSIONS Probable or proven invasive pulmonary aspergillosis was diagnosed in 14% of our study population and associated with significantly higher 30-day mortality rates. Although the performance of β-D-glucan was limited by low specificity and that of mycological culture by low sensitivity, the Aspergillus lateral-flow device seems to be a promising alternative to galactomannan testing, which remains the diagnostic gold standard for aspergillosis. Clinical trial registered with www.clinicaltrials.gov (NCT 02058316).

European Organization for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) host factors and invasive fungal infections in patients with haematological malignancies

OBJECTIVES Fulfilment of host factors defined by the revised European Organization for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria is required for establishing the diagnosis of possible or probable invasive fungal infection (IFI). This case-control study evaluates EORTC/MSG host factors among patients with haematological malignancies. METHODS Fifty-eight patients with haematological malignancies who developed probable (n = 38) or proven (n = 20) IFI over a 5 year period were retrospectively evaluated regarding EORTC/MSG host factors. Results were compared with those obtained from patients with haematological malignancies who did not develop IFI (116 patients who received systemic antifungal prophylaxis or empirical therapy and 116 patients who did not; all data collected in 2010). RESULTS Fourteen patients had invasive yeast infection and 44 patients had invasive mould infection (IMI). Prolonged neutropenia (35/58, 60% versus 29/116, 25%), prolonged systemic corticosteroid (cut-off 21 days: 13/58, 22% versus 6/116, 5%; cut-off 14 days: 18/58, 31% versus 9/116, 8%) and T cell suppressive therapy (35/44, 80% versus 69/116, 59%) were significantly associated with development of IFI/IMI in our cohort. Previous allogeneic stem cell transplantation (SCT; >6 months prior to episode) was not significantly associated with development of IMI (8/44, 18% versus 22/116, 19%), while recent SCT (<6 months prior to episode) was (11/44, 25% versus 12/116, 10%). CONCLUSIONS We conclude that host factors according to revised EORTC/MSG criteria were significantly associated with the development of IFI/IMI in our patients. Previous allogeneic SCT was not a predisposing host factor for the development of IMI. Concerning prolonged corticosteroid treatment, a cut-off of 14 days seems preferable to the proposed cut-off.

Bronchoalveolar lavage lateral-flow device test for invasive pulmonary aspergillosis in solid organ transplant patients: a semiprospective multicenter study.

Background Invasive pulmonary aspergillosis (IPA) remains an important cause of morbidity and mortality among patients undergoing solid organ transplantation (SOT). Because of the crude mortality of 80% to 90% in the absence of adequate treatment, timely diagnosis and early intervention with antifungal drugs are key factors in the successful treatment of IPA. Diagnosis, however, remains difficult. Therefore, new diagnostic tests are urgently needed. The Lateral-Flow Device (LFD) test is a rapid (15 min) single-sample point-of-care test that is based on the detection of an Aspergillus extracellular glycoprotein antigen by monoclonal antibody JF5. Methods This semiprospective multicenter study evaluated the LFD test for IPA diagnosis (established by galactomannan and culture results) by using bronchoalveolar lavage (BAL) samples from patients after SOT. Participating centers were the three Austrian Medical Universities of Innsbruck, Vienna, and Graz. Results Forty-seven BAL samples from 47 SOT patients were included (26 patients had undergone lung transplantation, 13 liver, 6 kidney, and 2 heart transplantation; 11 probable or proven IPA, 11 possible IPA, 25 no IPA) at the three Austrian Medical Universities of Innsbruck, Vienna, and Graz. Sensitivity and specificity, positive and negative predictive values, as well as diagnostic odds ratio of BAL LFD tests for probable IPA were 91%, 83%, 63%, 97%, and 50% (95% confidence interval, 5.4%–467%), respectively. Conclusion To conclude, the LFD test of BAL specimens is performed easily and provides accurate and rapidly available results in patients after SOT. Therefore, this new point-of-care test may be a promising diagnostic approach for detecting IPA using BAL specimens from SOT patients.

Detection and Differentiation of Bordetella spp. by Real-Time PCR

ABSTRACT Molecular detection of Bordetella pertussis DNA is a sensitive and specific method for the rapid diagnosis of pertussis. In this study, a new molecular assay for the detection and differentiation of Bordetella spp. based on automated DNA extraction and real-time PCR was evaluated. The analytical sensitivity of the new assay was determined by Probit analysis of serial dilutions of both cloned PCR products IS481 and IS1001 and cell suspensions of B. pertussis, B. parapertussis, and B. bronchiseptica. The specificity was analyzed by testing a number of pathogens producing respiratory infections. Moreover, a total of 92 clinical samples were investigated. The results were compared to those obtained by an in-house assay based on manual DNA extraction, followed by real-time PCR and detection of IS481. The analytical sensitivity of the new assay for the detection of IS481 and IS1001 was determined to be 2.2 and 1.2 genome equivalents/μl, respectively. The analytical sensitivity for the detection of B. pertussis, B. parapertussis, and B. bronchiseptica was determined to be 1.6, 1.0, and 2.7 genome equivalents/μl, respectively. When clinical specimens were tested with the new assay, 46 of 92 were found to be positive for Bordetella DNA. With the in-house assay, 45 samples tested positive. The new molecular assay proved to be suitable for the rapid diagnosis of pertussis in the routine diagnostic laboratory.

Diagnostic accuracy of the Aspergillus-specific bronchoalveolar lavage lateral-flow assay in haematological malignancy patients.

We evaluated the performance of the Aspergillus‐specific lateral‐flow device (LFD) test for diagnosing invasive pulmonary aspergillosis (IPA) in patients with underlying haematological malignancies. Participating centres were the two Austrian University Hospitals of Graz and Innsbruck. LFD performance was evaluated with 95 bronchoalveolar lavage fluid (BALF) samples from 72 patients collected prospectively in Graz, and with 24 BALF bio bank samples from 23 patients (21 samples with probable IPA) in Innsbruck. Invasive fungal infections were classified according to the revised European Organization of Research and Treatment of Cancer/Mycoses Study Group criteria. Overall, 27 patients (30 samples) had probable IPA, 32 (43 samples) possible and 36 (46 samples) did not fulfil IPA criteria. The vast majority of patients – in particular those with probable IPA – received mould‐active treatment before bronchoscopy. Sensitivity, specificity, positive predictive value and negative‐predictive‐value for probable IPA diagnosis using the BALF‐LFD test were 71%, 76%, 35% and 94% for the Graz cohort. Sensitivity of the BALF‐LFD test for probable IPA was 57% in Innsbruck bio bank samples. Our results indicate that the BALF‐LFD‐test provides fast results with moderate sensitivities in patients with underlying haematological malignancies. Similar to other diagnostic tests and biomarkers sensitivity of the test may be influenced by ongoing systemic mould‐active treatment.

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.

Detection of CMV DNA : Is EDTA whole blood superior to EDTA plasma?

The early diagnosis of human cytomegalovirus (CMV) infection in immunosuppressed patients has been improved by molecular detection of CMV DNA. In this study, corresponding EDTA whole blood and EDTA plasma specimens were obtained from 42 bone marrow transplant recipients. For detection of CMV DNA, two commercially available assays, the CMV HHV6,7,8 R-gene (ARGENE), and the artus CMV LC PCR Kit (QIAGEN), were employed. The linearity of both assays was determined by using a clinical EDTA whole blood sample with high CMV DNA load. With the CMV HHV6,7,8 R-gene test, CMV DNA was detected in 40 EDTA whole blood and in 19 EDTA plasma samples, while the artus CMV LC PCR Kit test detected CMV DNA in 27 EDTA whole blood and in 30 EDTA plasma samples. In conclusion, EDTA whole blood samples were found to be the superior material when using the CMV HHV6,7,8 R-gene test. However, this benefit may not exist when employing alternative assays.

Disseminated Geosmithia argillacea infection in a patient with gastrointestinal GvHD

Fungal infections remain a major complication after haematopoietic SCT. Patients with GvHD are especially at risk for pulmonary fungal infections. Prophylactic regimens for patients with GvHD include posaconazole and voriconazole, and have demonstrated ability to prevent invasive fungal infections in a majority of patients undergoing allo-SCT for haematological malignancies. However, zygomycetes, Fusarium spp., and other rare moulds may cause major problems due to their resistance to these commonly used antifungal agents. We report on a 52-year-old Caucasian male with a bcrabl positive Pro-B ALL, who was treated according to the risk adapted German Multicenter Protocol GMALL 07/ 2003 (http://www.kompetenznetz-leukaemie.de/content/ aerzte/studien/studienregister) and underwent allo-SCT with reduced intensity conditioning in January 2010. A grade II acute GvHD of the skin was successfully treated with corticosteroids. In October, the patient was readmitted because of severe diarrhea. Endoscopic examination of the gastrointestinal tract, including multiple biopsies was performed, revealing late onset gastrointestinal acute GvHD grade III. Because of diarrhea and subtherapeutical posaconazole serum levels of 0.24mg/L, the antifungal prophylaxis was changed to i.v. voriconazole 200mg twice daily. High-dose corticosteroid treatment with methylprednisone 2mg/kg per day was initiated, and mycophenolate mofetil dose was increased to 1.5mg/kg twice daily. Initially, the patient responded well to the treatment, but after 10 days, watery diarrhea reoccurred. Thus, infliximab (10mg/kg once weekly, two doses) was commenced as third line GvHD therapy. A few days later, the C-reactive protein markedly increased and the patient developed respiratory symptoms, together with an incomplete hemiparesis caused by a stroke. Concurrently, the serum galactomannan index (Bio-Rad Laboratories, Marnes-laCoquette, France) increased from 0.36 to 4.44 OD (normal range o0.5 OD) within a week, and increased up to 420 OD in the following days. A computed tomography scan of the lungs revealed a new infiltrate with a halo sign (Figure 1a). Broncho-alveolar lavage (BAL) was performed the next day, and the patient was empirically switched to liposomal amphotericin B (5mg/kg per day) and caspofungin (70mg per day). Gram stain obtained from BAL revealed fungal hyphae, and cultures from lavage fluid grew a mould (Figure 2a), microscopically resembling Penicillium or Paecilomyces (Figure 2b). The BAL galactomannan was 420 OD. Bacterial cultures, Pneumocystis jirovecii microscopy, PCR for CMV and mycobacteria were all negative. The mould was identified as Geosmithia argillacea by sequencing of rDNA ITS and b-tubulin gene (GenBank accession number HQ686279 and HQ686280, respectively). Thermotolerance tests showed that G. argillacea is highly thermotolerant with active growth up to 50 1C on Sabourauds and malt extract agar. Susceptibility testing revealed a high in vitro minimum inhibition concentration against voriconazole (432mg/L) and fluconazole (4256mg/L), but lower minimum inhibition concentrations to amphotericin B (1.0mg/L), posaconazole (0.25mg/L), itraconazole (0.5mg/L) and echinocandins (0.004–0.032mg/L). After 7 days of caspofungin and liposomal amphotericin B, the C-reactive protein decreased significantly and a follow-up computed tomography scan revealed the occurrence of a second lesion, whereas the halo sign of the primary infiltrate had resolved (Figure 1b). However, later in the course, the patient deteriorated and the C-reactive protein increased again. Aside from adaptations of the empiric antibacterial treatment, i.v. itraconazole 200mg twice daily was added. Despite triple antifungal therapy,