The effect of CFTR modulators on structural lung disease in cystic fibrosis

Background: Newly developed quantitative chest computed tomography (CT) outcomes designed specifically to assess structural abnormalities related to cystic fibrosis (CF) lung disease are now available. CFTR modulators potentially can reduce some structural lung abnormalities. We aimed to investigate the effect of CFTR modulators on structural lung disease progression using different quantitative CT analysis methods specific for people with CF (PwCF). Methods: PwCF with a gating mutation (Ivacaftor) or two Phe508del alleles (lumacaftor-ivacaftor) provided clinical data and underwent chest CT scans. Chest CTs were performed before and after initiation of CFTR modulator treatment. Structural lung abnormalities on CT were assessed using the Perth Rotterdam Annotated Grid Morphometric Analysis for CF (PRAGMA-CF), airway-artery dimensions (AA), and CF-CT methods. Lung disease progression (0–3 years) in exposed and matched unexposed subjects was compared using analysis of covariance. To investigate the effect of treatment in early lung disease, subgroup analyses were performed on data of children and adolescents aged &lt;18 years. Results: We included 16 modulator exposed PwCF and 25 unexposed PwCF. Median (range) age at the baseline visit was 12.55 (4.25–36.49) years and 8.34 (3.47–38.29) years, respectively. The change in PRAGMA-CF %Airway disease (-2.88 (−4.46, −1.30), p = 0.001) and %Bronchiectasis extent (-2.07 (−3.13, −1.02), p &lt; 0.001) improved in exposed PwCF compared to unexposed. Subgroup analysis of paediatric data showed that only PRAGMA-CF %Bronchiectasis (-0.88 (−1.70, −0.07), p = 0.035) improved in exposed PwCF compared to unexposed. Conclusion: In this preliminary real-life retrospective study CFTR modulators improve several quantitative CT outcomes. A follow-up study with a large cohort and standardization of CT scanning is needed to confirm our findings.</p

Title : Nasal potential measurements on the nasal floor and under the inferior turbinate : does it matter ?

International audienceAim : Measurement of nasal potential difference (NPD) is increasingly used as diagnostic test for cystic fibrosis (CF) and for in vivo evaluation of treatments aimed at correcting the defective function of the CFTR-protein. Several methods are used to measure NPD. This study explores the influence of the site of measurement and compares NPD results obtained on the nasal floor and under the inferior turbinate Methods : NPD was measured in 34 CF, 26 heterozygote and 61 control subjects. In every subject measurements were taken simultaneously under the inferior turbinate in one nostril , and on the nasal floor in the other nostril. Criteria for interpretable tracings were predefined. Repeat measurements were done in 57 persons. Results : More interpretable tracings were obtained under the turbinate (120/124) than on the nasal floor (109/124), p=0.015. Within each subject group, mean values obtained were similar for maximal basal potential, response to amiloride and total chloride response. Both techniques discriminate well between CF and controls. Repeatability was similar with both methods: mean differences between 2 measurements approximated zero for most values. Also after correction for different number of interpretable tracings, simulation of sample size calculation for use in CFTR corrective trials was slightly in favour of measurements obtained on the nasal floor. Conclusion : NPD measurements under the inferior turbinate and on the nasal floor have similar discriminative power for diagnostic use. Measurements under the turbinate result in a slightly higher proportion of interpretable tracings but sample size calculation slightly favours the nasal floor method

RÉFLEXION SUR LA PRISE EN CHARGE DE L’HYDRONÉPHROSE ANTÉNATALE

Si l’hydronéphrose anténatale (HNA) est la malformation congénitale la plus fréquente, sa prise en charge est cependant controversée surtout en ce qui concerne le bilan à réaliser et l’intérêt d’une prophylaxie. Des études récentes remettent en doute l’indication systématique d’une cystographie à la recherche d’un reflux associé tout comme le bénéfice de l’antibioprophylaxie sur la survenue d’infection urinaire. Une approche moins agressive est discutée tenant compte essentiellement des données échographiques obtenues en postnatal. Nous proposons un algorithme de prise en charge tenant compte de ces données

Assessing the Orthogonality of Phage-Encoded RNA Polymerases for Tailored Synthetic Biology Applications in <i>Pseudomonas</i> Species

The phage T7 RNA polymerase (RNAP) and lysozyme form the basis of the widely used pET expression system for recombinant expression in the biotechnology field and as a tool in microbial synthetic biology. Attempts to transfer this genetic circuitry from Escherichia coli to non-model bacterial organisms with high potential have been restricted by the cytotoxicity of the T7 RNAP in the receiving hosts. We here explore the diversity of T7-like RNAPs mined directly from Pseudomonas phages for implementation in Pseudomonas species, thus relying on the co-evolution and natural adaptation of the system towards its host. By screening and characterizing different viral transcription machinery using a vector-based system in P. putida., we identified a set of four non-toxic phage RNAPs from phages phi15, PPPL-1, Pf-10, and 67PfluR64PP, showing a broad activity range and orthogonality to each other and the T7 RNAP. In addition, we confirmed the transcription start sites of their predicted promoters and improved the stringency of the phage RNAP expression systems by introducing and optimizing phage lysozymes for RNAP inhibition. This set of viral RNAPs expands the adaption of T7-inspired circuitry towards Pseudomonas species and highlights the potential of mining tailored genetic parts and tools from phages for their non-model host

Mutant Lrp1 Knock-In Mice Generated by Recombinase-Mediated Cassette Exchange Reveal Differential Importance of the NPXY Motifs in the Intracellular Domain of LRP1 for Normal Fetal Development

Lrp1 knock-in mice carrying either a wild-type allele or three different mutated alleles encoding the multifunctional endocytic receptor LRP1 were generated by recombinase-mediated cassette exchange (RMCE). Reinsertion by RMCE of a wild-type allele led to a normal pattern and level of gene expression and a completely normal phenotype, indicating that the RMCE procedure itself is neutral with respect to the function of the gene locus. In contrast, reinsertion of mutated LRP1 alleles carrying either inactivating mutations in the proximal NPXY motif (NPTY→AATA) of the cytoplasmic domain or in the furin cleavage site (RHRR→AHAA) caused distinctive liver phenotypes: respectively, either a late fetal destruction of the organ causing perinatal death or a selective enlargement of von-Kupffer cell lysosomes reminiscent of a mild lysosomal storage without an apparent negative effect on animal survival. Notably, mutation of the distal NPXY motif overlapping with an YXXL motif (NPVYATL→AAVAATL) did not cause any obvious pathological effect. The mutations showed no effect on the LRP1 expression level; however, as expected, the proteolytic maturation of LRP1 into its two subunits was significantly impaired, although not completely abolished, in the furin cleavage mutant. These data demonstrate that RMCE is a reliable and efficient approach to generate multiple mutant knock-in alleles for in vivo functional analysis of individual domains or motifs of large multidomain proteins. Its application in Lrp1 reveals dramatically variant phenotypes, of which further characterization will definitively contribute to our understanding of the biology of this multifunctional receptor

Sinonasal disease among patients with primary ciliary dyskinesia: an international study

peer reviewedBackgroundSinonasal symptoms are a common feature of primary ciliary dyskinesia (PCD); however, literature about their severity and frequency, particularly during the life course, is scarce. Using baseline data from the Ear, nose and throat (ENT) Prospective International Cohort of PCD patients, we describe sinonasal disease in PCD.MethodsWe included participants who had a routine sinonasal examination during which they completed a symptoms questionnaire. We compared frequency of reported symptoms and examination findings among children and adults, and identified characteristics potentially associated with higher risk of sinonasal disease using ordinal regression.Results12 centres contributed 384 participants; median age was 16 years (IQR 9–22), and 54% were male. Chronic nasal problems were the most common feature, reported by 341 (89%). More adults (33; 24%) than children (10; 4%) described hyposmia. Quality of life was moderately affected by rhinosinusitis among 136 participants with completed SNOT-22 questionnaires (median score 31; IQR 23–45). Examinations revealed nasal polyps among 51 of 345 participants (15%) and hypertrophic inferior nasal turbinates among 127 of 341 participants (37%). Facial pain was detected in 50 of 342 participants (15%). Nasal polyps, hypertrophic turbinates, deviated septum and facial pain were found more commonly in adults than children. The only characteristic associated with higher risk of sinonasal disease was age 10 years and older.ConclusionsBased on our findings, regular sinonasal examinations are relevant for patients with PCD of all ages. There is a need for improved management of sinonasal disease supported by evidence-based guidelines