Summary Background In about 10% of patients worldwide and more than 50% of patients in Israel, cystic fibrosis results from nonsense mutations (premature stop codons) in the messenger RNA (mRNA) for ...the cystic fibrosis transmembrane conductance regulator (CFTR). PTC124 is an orally bioavailable small molecule that is designed to induce ribosomes to selectively read through premature stop codons during mRNA translation, to produce functional CFTR. Methods This phase II prospective trial recruited adults with cystic fibrosis who had at least one nonsense mutation in the CFTR gene. Patients were assessed in two 28-day cycles. During the first cycle, patients received PTC124 at 16 mg/kg per day in three doses every day for 14 days, followed by 14 days without treatment; in the second cycle, patients received 40 mg/kg of PTC124 in three doses every day for 14 days, followed by 14 days without treatment. The primary outcome had three components: change in CFTR-mediated total chloride transport; proportion of patients who responded to treatment; and normalisation of chloride transport, as assessed by transepithelial nasal potential difference (PD) at baseline, at the end of each 14-day treatment course, and after 14 days without treatment. The trial was registered with who.int/ictrp , and with clinicaltrials.gov , number NCT00237380. Findings Transepithelial nasal PD was evaluated in 23 patients in the first cycle and in 21 patients in the second cycle. Mean total chloride transport increased in the first treatment phase, with a change of −7·1 (SD 7·0) mV (p<0·0001), and in the second, with a change of −3·7 (SD 7·3) mV (p=0·032). We recorded a response in total chloride transport (defined as a change in nasal PD of −5 mV or more) in 16 of the 23 patients in the first cycle's treatment phase (p<0·0001) and in eight of the 21 patients in the second cycle (p<0·0001). Total chloride transport entered the normal range for 13 of 23 patients in the first cycle's treatment phase (p=0·0003) and for nine of 21 in the second cycle (p=0·02). Two patients given PTC124 had constipation without intestinal obstruction, and four had mild dysuria. No drug-related serious adverse events were recorded. Interpretation In patients with cystic fibrosis who have a premature stop codon in the CFTR gene, oral administration of PTC124 to suppress nonsense mutations reduces the epithelial electrophysiological abnormalities caused by CFTR dysfunction. Funding PTC Therapeutics, Cystic Fibrosis Foundation Therapeutics.
To compare pulmonary function measures, maximal respiratory pressure and fatigue of respiratory muscles between patients with Post-Polio Syndrome (PPS) and controls.
Cross-sectional study.
Patients ...with PPS (N = 12; age 62.1±11.6 years) able to walk for 6 minutes without human assistance; age-matched controls with no history of polio or pulmonary dysfunction (N = 12; age 62.2±6.5 years).
A body plethysmograph was used to quantify Residual Volume (RV), Total Lung Capacity (TLC), and Thoracic Gas Volume (TGV) etc. A manometer was used to measure Maximal Inspiratory Pressure (MIP) and Maximal Expiratory Pressure. A spirometer was used to measure Maximal Voluntary Ventilation (MVV). Surface electromyography (sEMG) recorded diaphragmatic muscle activity while performing MVV.
The control group had significantly higher TGV and showed improvement in MIP following the effort (difference of 5.5±4.0cmH2O) while the PPS group showed deterioration in MIP (difference of -2.5±5.0cmH2O). Subjects with scoliosis had significantly higher RV/TLC values compared with subjects without scoliosis. The 25th frequency percentile of the sEMG signal acquired during MVV was reduced in the PPS group.
Maximal respiratory pressure test and sEMG measurements may identify fatigue of respiratory muscles in patients with PPS. Early diagnosis of respiratory impairment may delay respiratory decline and future need of invasive respiratory aids.
Repair of injured lungs represents a longstanding therapeutic challenge. We show that human and mouse embryonic lung tissue from the canalicular stage of development (20-22 weeks of gestation for ...humans, and embryonic day 15-16 (E15-E16) for mouse) are enriched with progenitors residing in distinct niches. On the basis of the marked analogy to progenitor niches in bone marrow (BM), we attempted strategies similar to BM transplantation, employing sublethal radiation to vacate lung progenitor niches and to reduce stem cell competition. Intravenous infusion of a single cell suspension of canalicular lung tissue from GFP-marked mice or human fetal donors into naphthalene-injured and irradiated syngeneic or SCID mice, respectively, induced marked long-term lung chimerism. Donor type structures or 'patches' contained epithelial, mesenchymal and endothelial cells. Transplantation of differentially labeled E16 mouse lung cells indicated that these patches were probably of clonal origin from the donor. Recipients of the single cell suspension transplant exhibited marked improvement in lung compliance and tissue damping reflecting the energy dissipation in the lung tissues. Our study provides proof of concept for lung reconstitution by canalicular-stage human lung cells after preconditioning of the pulmonary niche.
Ricin, a highly potent plant-derived toxin, is considered a potential bioterrorism weapon due to its pronounced toxicity, high availability, and ease of preparation. Acute damage following pulmonary ...ricinosis is characterized by local cytokine storm, massive neutrophil infiltration, and edema formation, resulting in respiratory insufficiency and death. A designated equine polyclonal antibody-based (antitoxin) treatment was developed in our laboratory and proved efficacious in alleviating lung injury and increasing survival rates. Although short-term pathogenesis was thoroughly characterized in antitoxin-treated mice, the long-term damage in surviving mice was never determined. In this study, long-term consequences of ricin intoxication were evaluated 30 days post-exposure in mice that survived antitoxin treatment. Significant pulmonary sequelae were demonstrated in surviving antitoxin-treated mice, as reflected by prominent histopathological changes, moderate fibrosis, increased lung hyperpermeability, and decreased lung compliance. The presented data highlight, for the first time to our knowledge, the possibility of long-term damage development in mice that survived lethal-dose pulmonary exposure to ricin due to antitoxin treatment.
Primary ciliary dyskinesia (PCD) is a genetic disorder characterized by impaired ciliary function, leading to chronic sinopulmonary disease. The genetic causes of PCD are still evolving, while the ...diagnosis is often dependent on finding a ciliary ultrastructural abnormality and immotile cilia. Here we report a novel gene associated with PCD but without ciliary ultrastructural abnormalities evident by transmission electron microscopy, but with dyskinetic cilia beating.
Genetic linkage analysis was performed in a family with a PCD subject. Gene expression was studied in Chlamydomonas reinhardtii and human airway epithelial cells, using RNA assays and immunostaining. The phenotypic effects of candidate gene mutations were determined in primary culture human tracheobronchial epithelial cells transduced with gene targeted shRNA sequences. Video-microscopy was used to evaluate cilia motion.
A single novel mutation in CCDC65, which created a termination codon at position 293, was identified in a subject with typical clinical features of PCD. CCDC65, an orthologue of the Chlamydomonas nexin-dynein regulatory complex protein DRC2, was localized to the cilia of normal nasal epithelial cells but was absent in those from the proband. CCDC65 expression was up-regulated during ciliogenesis in cultured airway epithelial cells, as was DRC2 in C. reinhardtii following deflagellation. Nasal epithelial cells from the affected individual and CCDC65-specific shRNA transduced normal airway epithelial cells had stiff and dyskinetic cilia beating patterns compared to control cells. Moreover, Gas8, a nexin-dynein regulatory complex component previously identified to associate with CCDC65, was absent in airway cells from the PCD subject and CCDC65-silenced cells.
Mutation in CCDC65, a nexin-dynein regulatory complex member, resulted in a frameshift mutation and PCD. The affected individual had altered cilia beating patterns, and no detectable ultrastructural defects of the ciliary axoneme, emphasizing the role of the nexin-dynein regulatory complex and the limitations of certain methods for PCD diagnosis.
Background Impaired mucociliary clearance causes pulmonary disease in primary ciliary dyskinesia (PCD) and contributes to cystic fibrosis (CF) lung disease. Although the sinopulmonary disease is ...similar, morbidity and mortality are different. Both patients with PCD and patients with CF with pancreatic sufficiency (CF-PS) show no nutrient malabsorption and are diagnosed at a later age compared with patients with CF with pancreatic insufficiency (CF-PI). Methods Clinical status, microbiology, FEV1 , and high-resolution CT (HRCT) scans presented as total Brody score (CT-TBS) were compared for patients with PCD, CF-PI, and CF-PS, all treated at the same medical center, by the same team, and by a similar routine follow-up. Results One hundred sixty-four patients, 34 with PCD, 88 with CF-PI, and 42 with CF-PS were enrolled. PCD was diagnosed at a similar age as CF-PS but significantly later than CF-PI. Mean FEV1 % predicted was similar for the three groups. The rate of FEV1 change with age in PCD was similar to CF-PS but significantly lower than in CF-PI. Severity of structural lung disease (CT-TBS) was similar for PCD and CF-PS and significantly higher in CF-PI. No correlation between TBS or Pseudomonas aeruginosa infection and FEV1 in PCD was seen, whereas a negative correlation with FEV1 was observed for both CF groups. Conclusions Although in our study PCD was similar to CF-PS, the lack of correlation between FEV1 and age, CT-TBS, and P aeruginosa infection in PCD suggests that impaired mucociliary clearance is not the only cause for inducing pulmonary damage in these diseases. Furthermore, a comparison of disease characteristics for PCD and CF should distinguish between CF-PI and CF-PS as different entities.
Aim
Asthma scoring systems rely on physical examination findings. Point of care ultrasound may provide an objective means to document improvement in the work of breathing in paediatric lower airway ...obstruction.
Methods
Thirty children with wheeze on physical examination (cases) and 15 children presenting with abdominal pain (controls) were studied. Using point‐of‐care ultrasound, m‐mode tracing of lung was recorded above the right hemidiaphragm at the midclavicular line. Pleural line slope and excursion were measured before and after treatment.
Results
Twenty patients had a final slope measurement under 20°, and only three were admitted—one for hypoxia that resolved prior to ascending to the ward and another for poor compliance. Average decrease in pleural line slope after treatment was 43% and average decrease in pleural line excursion was 32%. Of the 10 children admitted, 8 had measurements over 25°. The correlation coefficient between pleural slope and pleural excursion was 0.67. All controls had a horizontal m‐mode tracing at the pleural line.
Conclusion
Oscillation of the m‐mode line at the pleura is seen in children with lower airway obstruction and is absent in controls. There appears to be a correlation between beta‐agonist therapy and decreased pleural line slope and excursion.
may cause allergic bronchopulmonary aspergillosis (ABPA), a complex condition that leads to worsening of airway inflammation and progressive damage and is diagnosed by specific criteria. In this ...report, we present six CF patients with respiratory deterioration that did not respond to appropriate antibiotic treatment. All had had A fumigatus in sputum cultures but did not fulfill the criteria of ABPA. Treatment with antifungal agents was followed by improvement in clinical condition. We suggest that in patients with CF, A fumigatus should be considered as a pathogen that may directly cause respiratory exacerbations. Antifungal therapy should be considered when deteriorating respiratory function is not responding to antibacterial therapy and A fumigatus is growing in sputum cultures.
Abstract Background In a substantial number of patients with non-cystic fibrosis (CF) bronchiectasis an etiology cannot be found. Various complex immunodeficiency syndromes account for a significant ...portion of these patients but the mechanism elucidating the predisposition for suppurative lung disease often remains unknown. Objective To investigate the cause and mechanism predisposing a patient to severe bronchiectasis. Methods A patient presenting with severe non-CF bronchiectasis was investigated. Whole exome analysis (WES) was performed and complemented by extensive immunophenotyping. Results The genetic analysis revealed an autosomal dominant gain-of-function mutation (AD- GOF) in the signal transducer and activator of transcription 1 (STAT1) in the patient. STAT1 phosphorylation studies showed increased phosphorylation of STAT1 after stimulation with interferon γ (IFN-γ). Immunophenotyping showed normal counts of CD4 and CD8 T cells, B and NK cells, but a reduction of all memory B cells especially class switched memory B cells. Minor changes in the CD8 T cell subpopulations were seen. Conclusions Early use of WES in the investigation of non-CF bronchiectasis was highly advantageous. The degree of impairment in class-switched memory B cells may predispose patients with AD- GOF mutations in STAT1 to suppurative sinopulmonary disease.
Despite recent progress in defining the ciliome, the genetic basis for many cases of primary ciliary dyskinesia (PCD) remains elusive. We evaluated five children from two unrelated, consanguineous ...Palestinian families who had PCD with typical clinical features, reduced nasal nitric oxide concentrations, and absent dynein arms. Linkage analyses revealed a single common homozygous region on chromosome 8 and one candidate was conserved in organisms with motile cilia. Sequencing revealed a single novel mutation in LRRC6 (Leucine-rich repeat containing protein 6) that fit the model of autosomal recessive genetic transmission, leading to a change of a highly conserved amino acid from aspartic acid to histidine (Asp146His). LRRC6 was localized to the cytoplasm and was up-regulated during ciliogenesis in human airway epithelial cells in a Foxj1-dependent fashion. Nasal epithelial cells isolated from affected individuals and shRNA-mediated silencing in human airway epithelial cells, showed reduced LRRC6 expression, absent dynein arms, and slowed cilia beat frequency. Dynein arm proteins were either absent or mislocalized to the cytoplasm in airway epithelial cells from a primary ciliary dyskinesia subject. These findings suggest that LRRC6 plays a role in dynein arm assembly or trafficking and when mutated leads to primary ciliary dyskinesia with laterality defects.
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