Performance of the AsperGenius® PCR assay for detecting azole resistant Aspergillus fumigatus in BAL fluids from allogeneic HSCT recipients: A prospective cohort study from Essen, West Germany.

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.

Emergence of azole-resistant invasive aspergillosis in HSCT recipients in Germany.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Inhibition of mTOR with everolimus and silencing by vascular endothelial cell growth factor-specific siRNA induces synergistic antitumor activity in multiple myeloma cells.

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.

Human chorionic gonadotropin and indolamine 2,3-dioxygenase in patients with GVHD.

GVHD is a major complication following allogeneic hematopoietic SCT, and is associated with substantial morbidity and mortality. Based on the results of our previous clinical study with females treated with human chorionic gonadotropin (hCG) as preconditioning therapy for in vitro fertilization, we hypothesized that low-dose hCG stimulates indoleamine-2,3-dioxygenase (IDO), IL 10 and regulatory T cells (Treg), thereby suppressing clinical manifestations of chronic GVHD. Active chronic GVHD localized at skin, subcutaneous tissue, joints or gastrointestinal tract that was refractory or intolerant to glucocorticoid therapy improved substantially in 12 of 20 patients treated with hCG for 8 weeks (off-label), enabling a glucocorticoid dose reduction of 28% (average). Twelve of 19 patients with chronic GVHD of the skin responded to hCG therapy with a reduction of 25% (average) in their total skin score. HCG treatment increased IDO expression at median by sevenfold in peripheral mononuclear cells and IL10 levels in serum up to twofold at median from the pretreatment baseline. Further, an expansion of the Treg cell population was measured in one patient, which is also associated with the induction of tolerance. This novel application of low-dose hCG was well tolerated and is of clinical interest for GVHD treatment.

Increased susceptibility for aspergillosis and post-transplant immune deficiency in patients with gene variants of TLR4 after stem cell transplantation.

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.

Additive antileukemia effects by GFI1B- and BCR-ABL-specific siRNA in advanced phase chronic myeloid leukemic cells.

Previous studies demonstrated selective inhibition of the BCR-ABL (breakpoint cluster region-Abelson murine leukemia oncogene) tyrosine kinase by RNA interference in leukemic cells. In this study, we evaluated the effect of BCR-ABL small interfering RNA (siRNA) and GFI1B siRNA silencing on chronic myeloid leukemia (CML) cells in myeloid blast crises. The GFI1B gene was mapped to chromosome 9 and is, therefore, located downstream of the BCR-ABL translocation in CML cells. Co-transfection of BCR-ABL siRNA and GFI1B siRNA dramatically decreased cell viability and significantly induced apoptosis and inhibited proliferation in K562 cells (P<0.0001) and primary advanced phase CML cells (P<0.0001) versus controls. Furthermore, combining of BCR-ABL siRNA and GFI1B siRNA significantly modified the expression of several relevant genes including Myc, MDR1, MRP1 and tyrosyl-phosphoproteins in primary CML cells. Our data suggest that silencing of both BCR-ABL siRNA and GFI1B siRNA is associated with an additive antileukemic effect against K562 cells and primary advanced CML cells, further validating these genes as attractive therapeutic targets.

Bronchiolitis obliterans after allogeneic hematopoietic SCT: further insight--new perspectives?

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.

Toll-like receptor 9, NOD2 and IL23R gene polymorphisms influenced outcome in AML patients transplanted from HLA-identical sibling donors.

We evaluated the influence of gene polymorphisms of TLR9 (T1237C; T1486C), IL23R (A1142G), and NOD2 SNP8 (R702W), SNP12 (G908R) and SNP13 (1007fs) on outcome of hematopoietic SCT in a homogenous group of 142 AML patients after non-T-cell-depleted myeloablative transplantation from HLA-identical sibling donors. In our retrospective study, we found that TLR9 gene variant at 1486 influenced transplant outcome. Estimated 5-year OS in patients with the CC gene variant of TLR9 was 70.2% compared with 44.8% (P<0.027) in patients with TC/TT of TLR9 gene. No significant influences on 5-year OS were found for gene polymorphisms of NOD2 or IL23R (A1142G) in this study group. The 5-year treatment-related mortality was lowest in patients with CC gene variant of TLR9 (7.8 vs 23.1%; NS). Acute GVHD grade III-IV was higher in patients with NOD2 gene variants (28 vs 12.8%; P=0.065). In contrast, patients transplanted from donors with the gene variant of IL23R had no occurrence of severe acute GVHD grade III-IV (0 vs 18.4%; P<0.048). However, multivariate analysis confirmed the influence of NOD2 gene variants on the occurrence of acute GVHD grade II-IV after transplant. These results suggest that the gene variants of TLR9, NOD2 and Il23R had influence on the outcome of transplant.

Improved outcome of hematopoietic SCT in patients with homozygous gene variant of Toll-like receptor 9.

Toll-like receptor 9 (TLR9) is part of the innate immune system, which is activated by CpG oligonucleotides (ODNs) and produces potent Th1-type innate and adaptive immune responses. It is reported that TLR9 gene variants, T1486C and T1237C, are associated with a reduced TLR9 expression compared with the wild-type gene. In two cohort analyses, we evaluated the influence of these gene variants on the outcome of transplant in 413 patients and donors. A retrospective analysis of the first cohort (n=293) showed that the homozygous CC gene variant of TLR9 (1486) compared with TC/TT gene variants was significantly associated with a markedly improved 5-year TRM (11.7 versus 36.4%, P<0.003), 5-year OS (86.1 vs 48.3%, P<0.001) and a lower relapse rate (13.2 vs 33.3%, P<0.007), whereas the occurrence of acute GVHD was not different. A prospectively performed analysis of the second cohort (n=120) and multivariate analyses confirmed the influence of the CC gene variant on these end points. Compared with patients with TC/TT gene at position 1486 of TLR9, patients with the homozygous CC gene variant had a lower TLR9 mRNA expression and a delayed T-cell immune reconstitution after transplant, which might prevent them from overwhelming immune responses as sepsis or systemic inflammatory response syndrome (SIRS) associated with an increased TRM. In vitro studies using CpG-rich ODNs showed an upregulation of TLR9 expression in cell lines with CC gene variant, but not in cell lines with wild-type gene.

Relation of an interleukin-23 receptor gene polymorphism to graft-versus-host disease after hematopoietic-cell transplantation.

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.

Cytochrome P450 2C19 loss-of-function polymorphism is associated with an increased treatment-related mortality in patients undergoing allogeneic transplantation.

The polymorphic gene expression of CYP2C19 causes individual variability in drug metabolism and thereby in pharmacologic and toxicologic responses. We genotyped 286 patients and their donors for the CYP2C19 gene who underwent allogeneic transplantation for various diseases and analyzed their outcome. Patients were classified as: poor metabolizers (PMs; 3.1%), intermediate metabolizers (IMs; 24.5%) and extensive metabolizers (EMs; 72.5%). Patients genotyped as PMs had significant higher hepato- and nephrotoxicities compared to IMs or EMs. Maximum bilirubin and serum creatinine levels measured after transplant were approximately twofold higher than those of EMs or IMs. The increased toxicity resulted in an increased 4-year estimate for transplant-related mortality (TRM) with 50+/-18.6% for PMs compared to 25.1+/-3.7% for EMs (P<0.018) and 22.7 +/-5.6% for IMs (P<0.042), whereas no significant influence for relapse rate, overall survival or incidence of acute graft-versus-host disease grade 2-4 were found between the groups. Multivariate analysis including all potential factors that might influence TRM confirmed that the genotype of CYP2C19 is an independent factor, which influenced TRM significantly. These results suggest that genotyping for CYP450 2C19 can help to identify patients with higher risk for TRM.

Therapeutic application of small interfering RNA directed against bcr-abl transcripts to a patient with imatinib-resistant chronic myeloid leukaemia.

RNA interference is referred to as the recently discovered process of sequence-specific, post-transcriptional gene silencing that is initiated by double-stranded RNA molecules known as small interfering RNAs (siRNA). We herein present a first report on the in vivo application of targeted non-virally delivered synthetic bcr-abl siRNA in a female patient with recurrent Philadelphia chromosome-positive chronic myeloid leukaemia (CML) resistant to imatinib (Y253F mutation) and chemotherapy after allogeneic haematopoietic stem cell transplantation. We found a remarkable inhibition of the overexpressed bcr-abl oncogene resulting in increased apoptosis of CML cells. In vivo siRNA application was well tolerated without any clinically adverse events. Our findings imply that the clinical application of synthetic siRNA is feasible, safe and has real potential for genetic-based therapies using synthetic non-viral carriers.

Myeloablative allogeneic hematopoietic stem cell transplantation in elderly patients.

This study aimed to evaluate the outcome following myeloablative allogeneic hematopoietic stem cell transplantation (SCT) among patients older than 50 yr of age. A total of 215 patients with a median age of 57 yr underwent allogeneic hematopoietic SCT for early (41%) or advanced (59%) hematologic malignancies. After a median follow-up of 36 months a 10-yr survival estimate of 56 +/- 6% could be assessed for patients in early disease stages while patients with advanced diseases showed a significantly decreased survival probability of 31 +/- 5% (p < 0.0002). Transplant related mortality (TRM) at day 100 and 365 post-transplant was 13% and 30% for early but increased to 21% and 49% for advanced disease stages. As major determinants of TRM advanced disease stage (p < 0.0001) and occurrence of grades II-IV graft-vs.-host disease (GVHD) (p < 0.0001) were identified. These results show that hematopoietic SCT following myeloablative conditioning is also applicable to elderly patients whereas disease stage and high-grade GVHD represent the essential prognostic factors for outcome.

Caspofungin as second-line therapy for fever of unknown origin or invasive fungal infection following allogeneic stem cell transplantation.

Caspofungin (CAS) is the first of a new class of antifungal agents, the echinocandins, that interfere with fungal cell wall synthesis by inhibition of glucan synthesis. Here, we report the results of 31 patients treated with CAS following allogeneic SCT. CAS was administered as a second-line agent to patients with invasive fungal infection (IFI) (n=15) or fever of unknown origin (n=16) who were recalcitrant to or intolerant of prior antifungal therapy. Unsuccessful first-line regimes included amphotericin B (n=17), liposomal amphotericin B (n=5), fluconazole (n=3), itraconazole (n=1), and voriconazole (n=2). All patients received concomitant immunosuppressive therapy for graft-versus-host disease. In 23 patients, cyclosporin A (CSA) and CAS were administered concurrently without any major side effects detected. Observed increases in GPT were not clinically significant. Normalization of serum creatinine and significant reductions in C-reactive protein were observed in response to CAS. Favorable outcome to CAS were documented in eight of 15 patients with IFI and in 15 of 16 patients with fever of unknown origin. CAS is a promising alternative in patients with IFI and fever of unknown origin in the setting of allogeneic SCT.