One year prospective survey of azole resistance in Aspergillus fumigatus at a French cystic fibrosis reference centre: prevalence and mechanisms of resistance.

BACKGROUND: Studies on Aspergillus fumigatus azole resistance in cystic fibrosis patients are scarce despite the fact that it is the most frequently isolated fungus from respiratory samples from these individuals. OBJECTIVES: To evaluate resistance prevalence, investigate mechanisms of resistance and explore the relationship between resistant isolates by genotyping. METHODS: We conducted a prospective 1 year study (from 1 January to 31 December 2015), based on the investigation of up to five colonies per sample from cystic fibrosis patients. RESULTS: Twenty-three (6.5%) isolates among the 355 tested were resistant to at least one triazole drug, using the EUCAST reference method, leading to a prevalence of 6.8% (6/88 patients). Analysis of resistance mechanisms highlighted TR34/L98H (n = 10), TR46/Y121F/T289A (n = 1), WT cyp51A (n = 11) and F46Y/M172V/N248T/D255E/E427K (n = 1). No genotype was shared between patients. CONCLUSIONS: This study showed a relatively stable resistance prevalence in comparison with the previous study conducted in 2010-11 (8%), although resistance mechanisms varied between the two studies.

Evaluation of quantitative PCR for early diagnosis of Pseudomonas aeruginosa infection in cystic fibrosis: a prospective cohort study.

OBJECTIVES: Early detection of Pseudomonas aeruginosa lung positivity is a key element in cystic fibrosis (CF) management. PCR has increased the accuracy of detection of many microorganisms. Clinical relevance of P. aeruginosa quantitative PCR (qPCR) in this context is unclear. Our aim was to determine P. aeruginosa qPCR sensitivity and specificity, and to assess the possible time saved by qPCR in comparison with standard practice (culture). METHODS: A multicentre cohort study was conducted over a 3-year period in 96 patients with CF without chronic P. aeruginosa colonization. Sputum samples were collected at each visit. Conventional culture and two-step qPCR (oprL qPCR and gyrB/ecfX qPCR) were performed for 707 samples. The positivity criteria were based on the qPCR results, defined in a previous study as follow: oprL qPCR positivity alone if bacterial density was <730 CFU/mL or oprL qPCR combined with gyrB/ecfX qPCR if bacterial density was ≥730 CFU/mL. RESULTS: During follow up, 36 of the 96 patients with CF were diagnosed on culture as colonized with P. aeruginosa. This two-step qPCR displayed a sensitivity of 94.3% (95% CI 79.7%-98.6%), and a specificity of 86.3% (95% CI 83.4%-88.7%). It enabled P. aeruginosa acquisition to be diagnosed earlier in 20 patients, providing a median detection time gain of 8 months (interquartile range 3.7-17.6) for them. CONCLUSIONS: Implementing oprL and gyrB/ecfX qPCR in the management of patients with CF allowed earlier detection of first P. aeruginosa lung positivity than culture alone.

Impact of donor-to-recipient weight ratio on survival after bilateral lung transplantation.

BACKGROUND: The aim of this study was to investigate the relationship between donor-to-recipient weight ratio and post-transplantation survival. METHODS: From February 1988 to November 2006, 255 adult bilateral lung transplantation patients from 2 different centers were retrospectively analyzed. The cohort was divided into 4 groups depending on the quartile ranges of the donor-to-recipient weight ratio. A time-to-event analysis was performed for risk of death after transplantation conditional on 5-year survival using Kaplan-Meier and Cox proportional hazards models. RESULTS: The mean weight ratio for the study cohort was 1.23 ± 0.39. For all lung transplant recipients during the study period, survival rate at 5 years was 58%. Median survival was 6.3 years in the cohort subgroup with weight ratio <1.23, whereas the median survival was 7.7 years for the cohort subgroup with weight ratio >1.23. Weight ratio >1.23 recipients had a significant survival advantage out to 5 years compared with weight ratio <1.23 recipients (66.1% vs 51.1%, P = .0126). With the aim to assess underweight and overweight donors vs recipients, we have divided all patients into 4 groups, from quartile 1 to 4, based on donor-to-recipient weight ratio. Weight ratio strata affected overall survival, with quartile 1 (lower weight ratio recipients) experiencing the lowest 5-year survival (39.1%), followed by quartile 2 (57.8%), quartile 4 (68.2%), and quartile 3 (70.3%) recipients. The effect of weight ratio strata on survival was statistically significant for the quartile 1 recipients (lower quartile) as compared with the 3 other quartiles. CONCLUSIONS: Our findings show a statistically significant effect of donor-to-recipient weight ratios on bilateral lung transplantation survival. A higher donor-to-recipient weight ratio was associated with improved survival after bilateral lung transplantation and likely reflects a mismatch between a relatively overweight donor vs recipient. In contrast, a lower donor-to-recipient ratio was associated with increased mortality after bilateral lung transplantation.

[Perceptions of cystic fibrosis patients, patient relatives and physicians: barriers or motivations to lung transplantation]. / Motivations et freins à la greffe chez patients, aidants et médecins dans la mucoviscidose.

INTRODUCTION: The aims of this study are to describe qualitatively the perceptions of three groups involved in the cystic fibrosis transplant decision, looking for similarities and differences between groups, and to identify those that act as motivations or barriers to transplantation. METHODS: Thirty patients, 26 patient relatives and 27 physicians were interviewed, and concept maps were constructed from those interviews. Their degree of transplant acceptance at the time of the interview was measured. RESULTS: There were motivations and barriers in the pre-, peri- and post-transplant period. Analysis revealed similar perceptions regarding the risks and benefits of transplantation, but also different perceptions in the specific concerns of each group. Patients and patient relatives expressed many questions and fears in their concept maps, and physicians expressed difficulties. CONCLUSIONS: This study highlights the value of better understanding the perceptions of patients, relatives and physicians, in order to remove some of the barriers to transplantation. It also demonstrates the benefits of education and support activities for patients and patient relatives prior to transplantation, and continuing education and supervision for physicians.

CFTR biomarkers: time for promotion to surrogate end-point.

In patients with cystic fibrosis, cystic fibrosis transmembrane conductance regulator (CFTR) biomarkers, such as sweat chloride concentration and/or nasal potential difference, are used as end-points of efficacy in phase-III clinical trials with the disease modifying drugs ivacaftor (VX-770), VX809 and ataluren. The aim of this project was to review the literature on reliability, validity and responsiveness of nasal potential difference, sweat chloride and intestinal current measurement in patients with cystic fibrosis. Data on clinimetric properties were collected for each biomarker and reviewed by an international team of experts. Data on reliability, validity and responsiveness were tabulated. In addition, narrative answers to four key questions were discussed and agreed by the team of experts. The data collected demonstrated the reliability, validity and responsiveness of nasal potential difference. Fewer data were found on reliability of sweat chloride concentration; however, validity and responsiveness were demonstrated. Validity was demonstrated for intestinal current measurement, but further information is required on reliability and responsiveness. For all three end-points, normal values were collected and further research requirements were proposed. This body of work adds useful information to support the promotion of CFTR biomarkers to surrogate end-points and to guide further research in the area.