Aspergillus fumigatus is the most common agent of invasive aspergillosis (IA). In recent years, resistance to triazoles, the mainstay of IA therapy, has emerged in different countries worldwide. IA ...caused by azole-resistant A. fumigatus (ARAF) shows an exceedingly high mortality. In this study, IA due to ARAF isolates in HSCT recipients in Germany was investigated.
The epidemiology of azole resistance in IA was analysed in two German haematology departments. Between 2012 and 2013, 762 patients received HSCT in Essen (n = 388) and Cologne (n = 374). Susceptibility testing of A. fumigatus isolates was performed by Etest, followed by EUCAST broth microdilution testing if elevated MICs were recorded. In all ARAF isolates the cyp51A gene was sequenced and the genotype was determined by microsatellite typing using nine short tandem repeats.
In total, A. fumigatus was recovered from 27 HSCT recipients. Eight patients had azole-resistant IA after HSCT, and seven of the cases were fatal (88%). All except one patient received antifungal prophylaxis (in five cases triazoles). TR34/L98H was the most common mutation (n = 5), followed by TR46/Y121F/T289A (n = 2). In one resistant isolate no cyp51A mutation was detected. Genotyping revealed genetic diversity within the German ARAF isolates and no clustering with resistant isolates from the Netherlands, India and France.
This report highlights the emergence of azole-resistant IA with TR34/L98H and TR46/Y121F/T289A mutations in HSCT patients in Germany and underscores the need for systematic antifungal susceptibility testing of A. fumigatus.
Abstract
In this study a commercially available multiplex real-time PCR (AsperGenius®) was evaluated for its efficacy in detecting Aspergillus fumigatus and azole resistance markers in comparison ...with conventional culture methods and galactomannan (GM) testing from BAL fluids in allogeneic HSCT recipients. Between January 2015 and May 2017 100 allogeneic HSCT recipients with pulmonary infiltrates and suspicion of invasive fungal infection were recruited to the study from a tertiary care center in Germany. BAL fluid was routinely assessed using the following diagnostic tests: AsperGenius® PCR assay, GM testing (cut-off: 1.0) and conventional culture. Susceptibility testing of azoles was performed by using Etest and, in case presenting elevated MICs, PCR for mutations in the cyp51A gene was carried out. Criteria of EORTC/MSG were used to classify the patients for invasive fungal disease. According to the EORTC/MSG criteria 23 patients presented with probable invasive aspergillosis (IA). Aspergillus PCR showed a sensitivity of 65% for probable IA cases. A combination of PCR and GM results in BAL displayed a sensitivity of 96% (22/23) and 100% specificity. Mutations in the cyp51A gene were detected by PCR in three cases (3/23; 13%) which were also found resistant with the culture method. In one case a Y121F/T289A mutation and in two cases a L98H were found. The combination of a commercial Aspergillus PCR assay and GM testing from BAL demonstrated a high sensitivity and specificity for diagnosing IA in allogeneic HSCT recipients. The Aspergillus PCR assay was not superior in detecting azole resistant A. fumigatus compared to culture.
High mortality rates of invasive fungal disease (IFD), especially invasive aspergillosis (IA), in immunocompromised haematological patients and current diagnostic limitations require improvement of ...detection of fungal pathogens by defining the optimal use of biomarkers and clinical samples. Concurrent bronchoalveolar lavage (BAL) and peripheral blood samples of 99 haematological patients with suspected IFD were investigated within a multicentre prospective study. Diagnostic performance of a galactomannan (GM) enzyme immune assay (EIA), a 1,3-β-D-glucan assay (BDG), an Aspergillus PCR, and a multifungal DNA-microarray (Chip) alone or in combination were calculated. IFD were classified as proven (n=3), probable (n=34), possible (n=33), and no IFD (n=29) according to EORTC/MSG criteria. GM, PCR, and Chip showed superior diagnostic performance in BAL than in blood, whereas specificity of BDG in BAL was poor (48% (14/29)). The combination of GM (BAL) with BDG (blood) showed sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and DOR (diagnostic odds ratio) of 92% (34/37), 93% (27/29), 94%, 90%, and 153.0, respectively. Combining GM (BAL) with PCR (BAL) showed convincing diagnostic potential for diagnosing IA with sensitivity, specificity, PPV, NPV, and DOR of 85% (17/20), 97% (28/29), 94%, 90%, and 158.7. Addition of the DNA-microarray resulted in further detection of two mucormycetes infections. In 1 out of 15 Aspergillus DNA-positive samples a triazole resistance-mediating Cyp51A mutation was found. Combination of biomarkers is superior to their sole use in diagnosing IFD, particularly IA. Integrating blood and BAL samples into a diagnostic algorithm is an advantageous approach.
Polymorphisms in cytokine genes can influence immune responses and inflammation and thereby affecting the outcome of hematopoietic stem-cell transplantation. We analyzed a single-nucleotide ...polymorphism in the gene for the interleukin-23 receptor (IL-23R) (1142G>A) in a cohort of 221 transplant recipients and their human leukocyte antigen (HLA)-identical sibling donors and in a second cohort of 186 transplant recipients and their HLA-identical unrelated donors. Genotypes were tested for an association with graft-versus-host disease (GVHD) by multivariate analysis. The donor's IL-23R genotype was significantly associated with a reduced risk of acute GVHD in both cohorts for patients after transplant. Analysis of all 407 transplant recipients showed that IL-23R (1142G>A, Arg381Gln) genotype of the donor was associated with a decreased risk of grades 2-4 acute GVHD (31.6 compared to 51.0%, P=0.02) and grades 3-4 severe acute GVHD (3.9 compared to 23.4%, P=0.003). Death in remission was significantly lower in patients transplanted from donors with variant IL23-R (11.7 versus 27.7%, P=0.028), whereas overall survival or relapse rates were not influenced significantly by the IL-23R genotype. Among recipients of hematopoietic cells from HLA-identical donors, the IL-23R (Arg381Gln) gene variant on the donor side has a protective effect on the occurrence of acute GVHD in recipients after transplantation.
Bronchiolitis obliterans (BO) is a late non-infectious pulmonary complication after allogeneic hematopoietic SCT. Among 982 patients after myeloablative hematopoietic SCT between January 2000 and ...October 2010, 68 were diagnosed with BO according to NIH criteria. The median onset of BO was 18 months post transplant, 5-year cumulative incidence was 5.8% and 5-year mortality 41%. BO prevalence rate was 10% among all long-term surviving hematopoietic SCT recipients and 12% among chronic GVHD-patients. Chronic GVHD, peripheral SCT and ABO blood group incompatibility were identified as risk factors associated with BO. IgG levels were significantly decreased at the onset of BO (6.7 g/L±0.7, P=0.001), the mean exhaled NO concentrations were lower in BO-patients than in stem cell recipients without BO (14 p.p.b.±0.9 vs 20 p.p.b.±2.1) or healthy controls (25 p.p.b.±2.4, P<0.001). Hypoxia-inducible factor 1 alpha (HIF-1α) was significantly elevated in BO as compared with healthy controls or GVHD-patients without lung involvement (340±61 vs 127±22 vs 140±32, P=0.02). Calculated 5-year survival was superior in female than in male BO-patients (86 vs 45%, P=0.04). These results emphasize the relevance of BO as serious late complication with substantial mortality and point to essential pathophysiological changes due to regulatory responses to hypoxia.
Introduction
Toll‐like receptors (TLRs) detect invading pathogens through several pattern‐recognition mechanisms and play a central role in the regulation of the immune system. In allogeneic ...hematopoietic stem cell transplantation (HSCT), the frequent opportunistic fungal infections remain an important cause of mortality and morbidity in these highly immunocompromised patients.
Methods
We analyzed 154 patients after allogeneic HSCT for acute leukemia for TLR4 gene variants 1063A/G (D299G) and 1363C/T (T399I) with their respective donors, and correlated the results with the incidence of invasive aspergillosis (IA) infection after transplant.
Results
Probable and proven IA in recipients was significantly increased if either recipients or donors exhibited one of the two TLR4 gene variants. In addition, recipients with TLR gene variants and IA showed a delayed T cell and NKT cell immune reconstitution after transplant. Increased susceptibility for IA was not associated with an increased rate of death‐in‐remission or decreased estimate for overall survival.
Conclusion
These findings reinforce the importance of genetic variants in innate immunity and IA among the recipients of allogeneic HSCT.
Angiogenesis has an important role in the pathogenesis and progression of multiple myeloma (MM). MM cells secrete vascular endothelial growth factor (VEGF), which further promotes proliferation of ...the tumor cells. Therefore, we evaluated the anti-myeloma effect of VEGF small interfering RNA (siRNA) silencing in MM cells and whether it can be augmented by the additional inhibition of the mammalian target of rapamycin (mTOR) by everolimus. We shown that everolimus inhibits cell growth of MM cells and other leukemic cells at low concentrations in a dose-dependent manner. After transfection with VEGF siRNA we observed a reduction of cell growth and VEGF expression in all studied cell lines: OPM-2, RPMI-8226, INA-6, JURKAT and RAJI. VEGF siRNA both significantly induced apoptosis and inhibited proliferation in OPM-2 cells (P<0.0001), RPMI-8226 (P<0.0001) and in INA-6 (P<0.01) versus controls. Co-treatment with VEGF siRNA and everolimus in MM cells resulted in an exaggerated inhibition of proliferation compared with VEGF siRNA or everolimus alone (P<0.0001) and enhanced induction of apoptosis compared with VEGF siRNA alone (P<0.03). In addition, the combination of VEGF siRNA and everolimus significantly reversed P-glycoprotein expression (P<0.005) and HIF-1α expression (P<0.001) of MM cells, respectively. Our data suggest that mTOR inhibition and silencing of VEGF expression is associated with synergistic antitumor activity and this combination treatment might be a suitable strategy for new therapeutic approaches using RNA interference in MM.
Taurolidine is an antimicrobial agent that was originally used in the local treatment of peritonitis and was shown to be effective in the prevention of catheter-related bloodstream infections ...(CR-BSI). In this pilot study, we used taurolidine solution as an intravenous (i.v.) lock into the totally implantable intravascular devices of 11 consecutive oncological patients with catheter-related bloodstream infections not responding to systemic antimicrobial chemotherapy. All patients recovered completely from the infection. No adverse drug effects were seen. Three patients were successfully retreated for a recurrent infection. Our data suggest a beneficial role of taurolidine i.v. lock for the therapy of catheter-related bloodstream infections in oncological patients. Taurolidine i.v. lock application is feasible and could especially be useful in infections resistant to antibiotic chemotherapy.
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