Relationship between Fungal Colonisation of the Respiratory Tract in Lung Transplant Recipients and Fungal Contamination of the Hospital Environment

International audienceBackgroundAspergillus colonisation is frequently reported after lung transplantation. The question of whether aspergillus colonisation is related to the hospital environment is crucial to prevention.MethodTo elucidate this question, a prospective study of aspergillus colonisation after lung transplantation, along with a mycological survey of the patient environment, was performed.ResultsForty-four consecutive patients were included from the day of lung transplantation and then examined weekly for aspergillus colonisation until hospital discharge. Environmental fungal contamination of each patient was followed weekly via air and surface sampling. Twelve patients (27%) had transient aspergillus colonisation, occurring 1–13 weeks after lung transplantation, without associated manifestation of aspergillosis. Responsible Aspergillus species were A. fumigatus (6), A. niger (3), A. sydowii (1), A. calidoustus (1) and Aspergillus sp. (1). In the environment, contamination by Penicillium and Aspergillus was predominant. Multivariate analysis showed a significant association between occurrence of aspergillus colonisation and fungal contamination of the patient’s room, either by Aspergillus spp. in the air or by A.fumigatus on the floor. Related clinical and environmental isolates were genotyped in 9 cases of aspergillus colonisation. For A. fumigatus (4 cases), two identical microsatellite profiles were found between clinical and environmental isolates collected on distant dates or locations. For other Aspergillus species, isolates were different in 2 cases; in 3 cases of aspergillus colonisation by A. sydowii, A. niger and A. calidoustus, similarity between clinical and environmental internal transcribed spacer and tubulin sequences was >99%.ConclusionTaken together, these results support the hypothesis of environmental risk of hospital acquisition of aspergillus colonisation in lung transplant recipients

Melflufen and dexamethasone in heavily pretreated relapsed and refractory multiple myeloma

Clinical trial information: NCT02963493Altres ajuts: Oncopeptides A

Daratumumab plus lenalidomide and dexamethasone for untreated myeloma

This is an accepted manuscript of an article published by Massachusetts Medical Society in New England Journal of Medicine on 30/05/2019, available online: https://doi.org/10.1056/NEJMoa1817249 The accepted version of the publication may differ from the final published version.Copyright © 2019 Massachusetts Medical Society. Lenalidomide plus dexamethasone is a standard treatment for patients with newly diagnosed multiple myeloma who are ineligible for autologous stem-cell transplantation. We sought to determine whether the addition of daratumumab would significantly reduce the risk of disease progression or death in this population. METHODS We randomly assigned 737 patients with newly diagnosed multiple myeloma who were ineligible for autologous stem-cell transplantation to receive daratumumab plus lenalidomide and dexamethasone (daratumumab group) or lenalidomide and dexamethasone alone (control group). Treatment was to continue until the occurrence of disease progression or unacceptable side effects. The primary end point was progression-free survival. RESULTS At a median follow-up of 28.0 months, disease progression or death had occurred in 240 patients (97 of 368 patients [26.4%] in the daratumumab group and 143 of 369 patients [38.8%] in the control group). The estimated percentage of patients who were alive without disease progression at 30 months was 70.6% (95% confidence interval [CI], 65.0 to 75.4) in the daratumumab group and 55.6% (95% CI, 49.5 to 61.3) in the control group (hazard ratio for disease progression or death, 0.56; 95% CI, 0.43 to 0.73; P<0.001). The percentage of patients with a complete response or better was 47.6% in the daratumumab group and 24.9% in the control group (P<0.001). A total of 24.2% of the patients in the daratumumab group, as compared with 7.3% of the patients in the control group, had results below the threshold for minimal residual disease (1 tumor cell per 105 white cells) (P<0.001). The most common adverse events of grade 3 or 4 were neutropenia (50.0% in the daratumumab group vs. 35.3% in the control group), anemia (11.8% vs. 19.7%), lymphopenia (15.1% vs. 10.7%), and pneumonia (13.7% vs. 7.9%).Published versio

A pair of Sub-Neptunes transiting the bright K-dwarf TOI-1064 characterised with CHEOPS

Funding: TGW, ACC, and KH acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant ST/R003203/1.We report the discovery and characterization of a pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 (TIC 79748331), initially detected in the Transiting Exoplanet Survey Satellite (TESS) photometry. To characterize the system, we performed and retrieved the CHaracterising ExOPlanets Satellite (CHEOPS), TESS, and ground-based photometry, the High Accuracy Radial velocity Planet Searcher (HARPS) high-resolution spectroscopy, and Gemini speckle imaging. We characterize the host star and determine Teff,⋆=4734±67K⁠, R⋆=0.726±0.007R⊙⁠, and M⋆=0.748±0.032M⊙⁠. We present a novel detrending method based on point spread function shape-change modelling and demonstrate its suitability to correct flux variations in CHEOPS data. We confirm the planetary nature of both bodies and find that TOI-1064 b has an orbital period of Pb = 6.44387 ± 0.00003 d, a radius of Rb = 2.59 ± 0.04 R⊕, and a mass of Mb=13.5+1.7−1.8 M⊕, whilst TOI-1064 c has an orbital period of Pc=12.22657+0.00005−0.00004 d, a radius of Rc = 2.65 ± 0.04 R⊕, and a 3σ upper mass limit of 8.5 M⊕. From the high-precision photometry we obtain radius uncertainties of ∼1.6 per cent, allowing us to conduct internal structure and atmospheric escape modelling. TOI-1064 b is one of the densest, well-characterized sub-Neptunes, with a tenuous atmosphere that can be explained by the loss of a primordial envelope following migration through the protoplanetary disc. It is likely that TOI-1064 c has an extended atmosphere due to the tentative low density, however further radial velocities are needed to confirm this scenario and the similar radii, different masses nature of this system. The high-precision data and modelling of TOI-1064 b are important for planets in this region of mass–radius space, and it allow us to identify a trend in bulk density–stellar metallicity for massive sub-Neptunes that may hint at the formation of this population of planets.Publisher PDFPeer reviewe

TOI-836 : a super-Earth and mini-Neptune transiting a nearby K-dwarf

Funding: TGW, ACC, and KH acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant ST/R003203/1.We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5 mag), high proper motion (∼200 mas yr−1), low metallicity ([Fe/H]≈−0.28) K-dwarf with a mass of 0.68 ± 0.05 M⊙ and a radius of 0.67 ± 0.01 R⊙. We obtain photometric follow-up observations with a variety of facilities, and we use these data-sets to determine that the inner planet, TOI-836 b, is a 1.70 ± 0.07 R⊕ super-Earth in a 3.82 day orbit, placing it directly within the so-called ‘radius valley’. The outer planet, TOI-836 c, is a 2.59 ± 0.09 R⊕ mini-Neptune in an 8.60 day orbit. Radial velocity measurements reveal that TOI-836 b has a mass of 4.5 ± 0.9 M⊕, while TOI-836 c has a mass of 9.6 ± 2.6 M⊕. Photometric observations show Transit Timing Variations (TTVs) on the order of 20 minutes for TOI-836 c, although there are no detectable TTVs for TOI-836 b. The TTVs of planet TOI-836 c may be caused by an undetected exterior planet.Publisher PDFPeer reviewe

TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf

We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright ($T = 8.5$ mag), high proper motion ($\sim\,200$ mas yr$^{-1}$), low metallicity ([Fe/H]$\approx\,-0.28$) K-dwarf with a mass of $0.68\pm0.05$ M$_{\odot}$ and a radius of $0.67\pm0.01$ R$_{\odot}$. We obtain photometric follow-up observations with a variety of facilities, and we use these data-sets to determine that the inner planet, TOI-836 b, is a $1.70\pm0.07$ R$_{\oplus}$ super-Earth in a 3.82 day orbit, placing it directly within the so-called 'radius valley'. The outer planet, TOI-836 c, is a $2.59\pm0.09$ R$_{\oplus}$ mini-Neptune in an 8.60 day orbit. Radial velocity measurements reveal that TOI-836 b has a mass of $4.5\pm0.9$ M$_{\oplus}$ , while TOI-836 c has a mass of $9.6\pm2.6$ M$_{\oplus}$. Photometric observations show Transit Timing Variations (TTVs) on the order of 20 minutes for TOI-836 c, although there are no detectable TTVs for TOI-836 b. The TTVs of planet TOI-836 c may be caused by an undetected exterior planet

TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf

peer reviewe

Evaluation du risque lié à l'exposition aérienne à Aspergillus fumigatus

Aspergillus fumigatus est un champignon filamenteux pathogène responsable de différentes formes d infections pulmonaires allergiques sur les sujets immunocompétents et d infections invasives chez les patients neutropéniques. L inhalation de spores est le mode habituel de contamination suggérant un rôle majeur de l environnement dans l épidémiologie de l aspergillose. Cependant, la relation entre les concentrations d Aspergillus dans l air et la probabilité d infections ne sont pas connues. Dans cette étude, trois approches complémentaires ont été proposées pour analyser cette relation. In vitro, nous avons utilisé un dispositif de culture en interface air-liquide pour analyser les conséquences de l exposition de cellules pulmonaires A549 à différentes concentrations de spores d Aspergillus fumigatus. Aucun effet significatif sur la production de cytokines pro-inflammatoires n'a été retrouvé suite à cette exposition, même lorsque cette exposition aspergillaire était combinée avec une exposition au formaldéhyde. In vivo, la relation entre l exposition à des spores d Aspergillus et la survenue d une infection a été étudiée dans un modèle murin d aspergillose invasive en utilisant la souche de référence Af293 d Aspergillus fumigatus. Dans une approche bayésienne la relation dose-infection entre probabilité d infection et exposition aux spores a été estimée en utilisant le modèle exponentiel et le modèle plus flexible bêta-Poisson. Ceci a permis d estimer la dose infectieuse 50 à 1,8-1,9.104 spores inhalées viables. Secondairement, ce modèle a été utilisé pour mettre au point un nouveau modèle de réactivation d aspergillose et étudier l efficacité de l amphotéricine B liposomale dans la prophylaxie de l aspergillose invasive. Chez l homme, nous avons tenté d estimer la relation entre l exposition environnementale aux spores fongiques et l incidence de la colonisation ou de l infection aspergillaire chez 44 transplantés pulmonaires étudiée de façon consécutive. A l'aide d'un modèle de régression par GEE, nous avons trouvé une relation significative entre la contamination des surfaces par Aspergillus et l incidence de la colonisation. De plus, nous avons montré des identités génotypiques entre les isolats cliniques et environnementaux d Aspergillus, ce qui confirme les risques d acquisition d Aspergillus dans le cadre hospitalier. Globalement, ces résultats apportent des données nouvelles sur la relation entre la contamination environnementale et la probabilité d aspergillose chez les patients immunodéprimésAspergillus fumigatus is an opportunistic fungal pathogen responsible for various respiratory diseases in normal hosts and severe invasive infections in neutropenic patients. Spore inhalation is the usual route of Aspergillus infection, suggesting a determining role of environmental contamination in the epidemiology of aspergillosis. However the relationship between Aspergillus concentration in the air and probability of infection is not quantitatively known. In this study, three different approaches were proposed to analyse this relationship. In vitro we used an air-liquid interface module to expose pulmonary A549 cells to high concentrations of A. fumigatus spores, but found not effect of exposure on the production of pro-inflammatory cytokines, even when exposure was combined with exposure to formaldehyde. In vivo, the relationship between spore exposure and infection was examined in a murine model of invasive aspergillosis, using the reference Af293 strain of A. fumigatus. In a bayesian approach, the dose-response relationship between the probability of infection and spore exposure was approximated using the exponential model and the more flexible beta-Poisson model. It allowed estimating the median infective dose at 1.8-1.9x104 inhaled viable spores. Further, this model was used to develop a unique model of reactivating aspergillosis and then to examine the efficacy of liposomal amphotericin B on prophylaxis of aspergillosis. In human, we attempted to estimate the relationship between environmental exposure to fungal spores and the incidence of Aspergillus colonization or infection in 44 consecutive lung transplant recipients. In a GEE multivariate analysis, we found a significant relationship between surface contamination by Aspergillus and the incidence of colonization. Furthermore, we found genotypic similarities between clinical and environmental isolates of Aspergillus, which confirm the risk of acquisition of Aspergillus in the hospital setting. Altogether, this result provides new insights into the relationship between airborne exposure and probability of aspergillosis in immunocompromised hostsPARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF

Bayesian development of a dose-response model for <em>Aspergillus fumagitus</em> and invasive aspergillosis

Invasive aspergillosis (IA) is a major cause of mortality in immunocompromized hosts, most often consecutive to the inhalation of spores of Aspergillus. However, the relationship between Aspergillus concentration in the air and probability of IA is not quantitatively known. In this study, this relationship was examined in a murine model of IA. Immunosuppressed Balb/c mice were exposed for 60 minutes at day 0 to an aerosol of A. fumigatus spores (Af293 strain). At day 10, IA was assessed in mice by quantitative culture of the lungs and galactomannan dosage. Fifteen separate nebulizations with varying spore concentrations were performed. Rates of IA ranged from 0% to 100% according to spore concentrations. The dose-response relationship between probability of infection and spore exposure was approximated using the exponential model and the more flexible beta-Poisson model. Prior distributions of the parameters of the models were proposed then updated with data in a Bayesian framework. Both models yielded close median dose-responses of the posterior distributions for the main parameter of the model, but with different dispersions, either when the exposure dose was the concentration in the nebulized suspension or was the estimated quantity of spores inhaled by a mouse during the experiment. The median quantity of inhaled spores that infected 50% of mice was estimated at 1.8×10(4) and 3.2×10(4) viable spores in the exponential and beta-Poisson models, respectively. This study provides dose-response parameters for quantitative assessment of the relationship between airborne exposure to the reference A. fumigatus strain and probability of IA in immunocompromized hosts