Acquired dysfunction of CFTR underlies cystic fibrosis-like disease of the canine gallbladder.

Mucocele formation in dogs is a unique and enigmatic muco-obstructive disease of the gallbladder caused by the amassment of abnormal mucus that bears striking pathological similarity to cystic fibrosis. We investigated the role of cystic fibrosis transmembrane conductance regulatory protein (CFTR) in the pathogenesis of this disease. The location and frequency of disease-associated variants in the coding region of CFTR were compared using whole genome sequence data from 2,642 dogs representing breeds at low-risk, high-risk, or with confirmed disease. Expression, localization, and ion transport activity of CFTR were quantified in control and mucocele gallbladders by NanoString, Western blotting, immunofluorescence imaging, and studies in Ussing chambers. Our results establish a significant loss of CFTR-dependent anion secretion by mucocele gallbladder mucosa. A significantly lower quantity of CFTR protein was demonstrated relative to E-cadherin in mucocele compared with control gallbladder mucosa. Immunofluorescence identified CFTR along the apical membrane of epithelial cells in control gallbladders but not in mucocele gallbladder epithelium. Decreases in mRNA copy number for CFTR were accompanied by decreases in mRNA for the Cl-/[Formula: see text] exchanger SLC26A3, K+ channels (KCNQ1, KCNN4), and vasoactive intestinal polypeptide receptor (VIPR1), which suggest a driving force for change in secretory function of gallbladder epithelial cells in the pathogenesis of mucocele formation. There were no significant differences in CFTR gene variant frequency, type, or predicted impact comparing low-risk, high-risk, and definitively diagnosed groups of dogs. This study describes a unique, naturally occurring muco-obstructive disease of the canine gallbladder, with uncanny similarity to cystic fibrosis, and driven by the underlying failure of CFTR function.NEW & NOTEWORTHY Cystic fibrosis transmembrane conductance regulatory protein (CFTR) genomic variants and expression of mRNA, protein, and electrogenic anion secretory activity of CFTR were characterized in dog gallbladder. Acquired inhibition of CFTR expression by gallbladder epithelium was identified as underpinning a naturally occurring muco-obstructive disease of the dog gallbladder that bears striking pathological similarity to animal models of cystic fibrosis.

Evaluation of the drug-drug interaction between triazole antifungals and cystic fibrosis transmembrane conductance regulator modulators in a real-life cohort.

Limited data on the clinical management of drug-drug interactions between triazoles and Cystic Fibrosis transmembrane conductance regulator (CFTR) modulators are available. We retrospectively evaluated azole target attainment and dose adaptations in patients from two Dutch CF centres concomitantly receiving triazoles and CFTR modulators. In total, 21 patients with 59 triazole trough concentrations were evaluated. Subtherapeutic concentrations were frequently observed, especially for itraconazole and voriconazole. Of the investigated antifungal agents, posaconazole appears the most preferable option. Our results emphasize the importance of adequate management of this interaction and underpin the added value of therapeutic drug monitoring of triazoles in this population.

Fungal infections are serious complications in Cystic Fibrosis (CF) patients. We evaluated patients concomitantly receiving triazoles and CF transmembrane conductance regulator modulators: subtherapeutic triazole exposure was frequently observed. Posaconazole appears the preferable antifungal agent.

Antifungal susceptibility patterns for Aspergillus, Scedosporium, and Exophiala isolates recovered from cystic fibrosis patients against amphotericin B, and three triazoles and their impact after long-term therapies.

In cystic fibrosis (CF) patients, fungal colonization of the respiratory tract is frequently found. Aspergillus fumigatus, Scedosporium genus, and Exophiala dermatitidis are the most commonly isolated moulds from the respiratory tract secretions of CF patients. The aim of this 5-year surveillance study was to identify trends in species distribution and susceptibility patterns of 212 mould strains identified as Aspergillus spp., Scedosporium spp., and Exophiala spp., isolated from sputum of 63 CF patients who received long-term therapy with itraconazole (ITR) and/or voriconazole (VRC). The Aspergillus isolates were identified as members of the sections Fumigati (n = 130), Flavi (n = 22), Terrei (n = 20), Nigri (n = 8), Nidulantes (n = 1), and Usti (n = 1). Among the 16 species of the genus Scedosporium, 9 were S. apiospermum, 3 S. aurantiacum, and 4 S. boydii. Among the 14 Exophiala species, all were molecularly identified as E. dermatitidis. Overall, 94% (15/16) of Scedosporium spp., 50% (7/14) of E. dermatitidis, and 7.7% (14/182) of Aspergillus spp. strains showed high MIC values (≥8 µg/ml) for at least one antifungal. Particularly, 8.9% (19/212) of isolates showed high MIC values for amphotericin B, 11.7% (25/212) for ITR, 4.2% (9/212) for VRC, and 3.3% (7/212) for posaconazole. In some cases, such as some A. fumigatus and E. dermatitidis isolates recovered from the same patient, susceptibility to antifungal azoles decreased over time. We show that the use of azoles for a long time in CF patients causes the selection/isolation of mould strains with higher MIC values.

The use of azoles for a long time in cystic fibrosis patients causes the selection/isolation of Aspergillus, Scedosporium, and Exophiala species with higher MIC values.

Outcome of patients with cystic fibrosis colonized by Scedosporium and Lomentospora species: A longitudinal cohort study.

Scedosporium and Lomentospora species rank second among the filamentous fungi colonizing the airways of cystic fibrosis (CF) patients. These fungi could be responsible for allergic bronchopulmonary mycosis (ABPM) and bronchitis before lung transplantation and invasive infections after. However, their role in CF lung disease is debated. This study aimed to identify clinical or environmental factors associated with an airway colonization by Scedosporium/Lomentospora species in patients with CF over a period of 7 years. A longitudinal cohort study was conducted from 2008 to 2014 in the CF reference centre in Lyon, France, to compare the characteristics of patients with Scedosporium/Lomentospora colonized and non-colonized patients. During the study period, 283 patients completed the clinical and microbiological follow-up. The analysis revealed that a higher number and duration of hospitalizations, an increased number of courses of parenteral antibiotic therapy, a history of ABPA, and treatment by itraconazole were significantly associated with an airway colonization by Scedosporium/Lomentospora species. The rate of decline of forced expiratory volume in the first second was not statistically different between colonized and non-colonized patients. This study provides evidence that patients colonized by Scedosporium/Lomentospora species require more medical care than non-colonized patients. Additional care could be in part explained by the management of Scedosporium/Lomentospora-related diseases such as ABPM or bronchitis. However, we did not demonstrate a faster rate of decline of respiratory function or body mass index in colonized patients, suggesting, as previously reported, that colonization of the airways by these fungi does not play a significant role in the progression of CF disease.

This prospective study did not demonstrate a faster rate of decline of respiratory function or body mass index in cystic fibrosis (CF) patients colonized by Scedosporium/Lomentospora species compared to non-colonized patients, suggesting that these fungi do not play a significant role in the progression of CF disease.

Transcriptomic analysis of lung development in wildtype and CFTR-/- sheep suggests an early inflammatory signature in the CF distal lung.

The precise molecular events initiating human lung disease are often poorly characterized. Investigating prenatal events that may underlie lung disease in later life is challenging in man, but insights from the well-characterized sheep model of lung development are valuable. Here, we determine the transcriptomic signature of lung development in wild-type sheep (WT) and use a sheep model of cystic fibrosis (CF) to characterize disease associated changes in gene expression through the pseudoglandular, canalicular, saccular, and alveolar stages of lung growth and differentiation. Using gene ontology process enrichment analysis of differentially expressed genes at each developmental time point, we define changes in biological processes (BP) in proximal and distal lung from WT or CF animals. We also compare divergent BP in WT and CF animals at each time point. Next, we establish the developmental profile of key genes encoding components of ion transport and innate immunity that are pivotal in CF lung disease and validate transcriptomic data by RT-qPCR. Consistent with the known pro-inflammatory phenotype of the CF lung after birth, we observe upregulation of inflammatory response processes in the CF sheep distal lung during the saccular stage of prenatal development. These data suggest early commencement of therapeutic regimens may be beneficial.

Nystatin is commonly prescribed as prophylaxis in children beyond the neonatal age.

The indications for nystatin as prophylaxis or treatment are limited. In the PASOAP (Pediatric Antifungal Stewardship Optimizing Antifungal Prescription) study, high use of nystatin in hospitalized children beyond the neonatal age was observed. In this report, we present the data on nystatin use in infants and children ≥ 3 months who participated in the PASOAP study. Nystatin was prescribed mainly for prophylaxis. Congenital heart disease, cystic fibrosis, and chronic renal disease were the most commonly reported conditions in children receiving prophylactic nystatin. There is sparse evidence supporting the use of nystatin prophylaxis beyond neonates; trials in specific pediatric patient groups are required.

The topical antifungal nystatin has not many indications. Prophylaxis of invasive candidiasis in very low birth weight neonates is one of them. In our study, we found that nystatin prophylaxis was used frequently beyond this specific neonatal group. Stronger evidence justifying its use is required.

Cystic fibrosis-related diabetes is caused by islet loss and inflammation.

Cystic fibrosis-related (CF-related) diabetes (CFRD) is an increasingly common and devastating comorbidity of CF, affecting approximately 35% of adults with CF. However, the underlying causes of CFRD are unclear. Here, we examined cystic fibrosis transmembrane conductance regulator (CFTR) islet expression and whether the CFTR participates in islet endocrine cell function using murine models of ß cell CFTR deletion and normal and CF human pancreas and islets. Specific deletion of CFTR from murine ß cells did not affect ß cell function. In human islets, CFTR mRNA was minimally expressed, and CFTR protein and electrical activity were not detected. Isolated CF/CFRD islets demonstrated appropriate insulin and glucagon secretion, with few changes in key islet-regulatory transcripts. Furthermore, approximately 65% of ß cell area was lost in CF donors, compounded by pancreatic remodeling and immune infiltration of the islet. These results indicate that CFRD is caused by ß cell loss and intraislet inflammation in the setting of a complex pleiotropic disease and not by intrinsic islet dysfunction from CFTR mutation.

Lessons learned from the cystic fibrosis pig.

Deficient function in the anion channel cystic fibrosis (CF) transmembrane conductance regulator is the fundamental cause for CF. This is a monogenic condition that causes lesions in several organs including the respiratory tract, pancreas, liver, intestines, and reproductive tract. Lung disease is most notable, given it is the leading cause of morbidity and mortality in people with CF. Shortly after the identification of CF transmembrane conductance regulator, CF mouse models were developed that did not show spontaneous lung disease as seen in humans, and this spurred development of additional CF animal models. Pig models were considered a leading choice for several reasons including their similarity to humans in respiratory anatomy, physiology, and in size for translational imaging. The first CF pig models were reported in 2008 and have been extremely valuable to help clarify persistent questions in the field and advance understanding of disease pathogenesis. Because CF pigs are susceptible to lung disease like humans, they have direct utility in translational research. In addition, CF pig models are useful to compare and contrast with current CF mouse models, human clinical studies, and even newer CF animal models being characterized. This "triangulation" strategy could help identify genetic differences that underlie phenotypic variations, so as to focus and accelerate translational research.

SINUSITIS, BRONCHIECTASIS, AND FLATUS IN A SUMATRAN ORANGUTAN (PONGO ABELII): COULD THIS BE CYSTIC FIBROSIS?

A 31-yr-old male Sumatran orangutan (Pongo abelii) presented with 14 yr of chronic purulent nasal drainage and cough with intermittent exacerbation of symptoms requiring systemic antibiotic treatment. He was diagnosed with a cystic fibrosis (CF)-like condition. Evaluation consisted of bronchoscopy with bronchoalveolar lavage, culture, and computed tomography scanning of the sinuses and chest. Although the presence of low fecal elastase activity increased the suspicion for a diagnosis of CF, pilocarpine iontophoresis with sweat collection and analysis ("sweat testing") was inconclusive. Medical management included twice-daily nebulization with bronchodilators and alternating month inhaled antibiotics, pancreatic enzyme replacement therapy, and simethicone as needed. Sinopulmonary and gastrointestinal symptoms improved substantially with treatment. Several years later, the animal died acutely of colonic volvulus. Necropsy and histopathology confirmed CF-like lung disease with chronic air sacculitis.

Modeling of asthma, COPD and cystic fibrosis in sheep.

Sheep naturally allergic to Ascaris suum antigen have been used to study the pathophysiology of asthma and more recently allergic rhinitis, chronic obstructive pulmonary disease (COPD) and cystic fibrosis. The utility of the model as it relates to the study of these diseases is discussed.

Mapping the bovine homolog of the human cystic fibrosis gene.

Human cDNA probe H1.6 (clone 10-1) encoding cystic fibrosis transmembrane conductance regulator (CFTR) was used to map the bovine homolog of CFTR. Using a panel of bovine x rodent hybrid somatic cells, the homolog was mapped to bovine syntenic group U13 which corresponds to chromosome 4. CFTR is 97.7% concordant with syntenic markers T-cell receptor beta (TCRB) and P-glycoprotein 3 (PGY3). The comparative gene maps of CFTR, TCRB, and PGY3 on human chromosome 7, bovine chromosome 4, and mouse chromosome 5 and 6 indicate conservation of synteny, although internal rearrangements relative to HSA 7 are present in both cattle and mice.

Nonhuman primate models for human disease.

The value of nonhuman primates as models for a variety of human diseases is well documented. These species have been used extensively during the past 25 years or so as models for a variety of bacterial, viral, and parasitic diseases, either as naturally occurring or experimentally induced infections. They are often the only nonhuman species susceptible to experimental infection with agents of human disease. Spontaneous diseases of nonhuman primates are often comparable to human diseases, and with the continued long-term maintenance of nonhuman primates in the laboratory as well as in domestic breeding colonies, it is reasonable to assume that additional disease models will be discovered. Such models may include degenerative diseases, diseases and/or lesions associated with the aging process, and genetic diseases. In this article we have reviewed four spontaneous diseases and one induced disease that have essentially identical counterparts in humans. Three of these are bacterial diseases that currently cause severe and sometimes fatal infections in humans; one is a degenerative disease that is usually progressive and fatal in humans, and one is possibly a genetic disease for which there is currently no animal model. The clinical and pathologic similarities between these nonhuman primate diseases and their human counterpart make these nonhuman primate diseases potentially valuable models for further studies on the etiology, pathogenesis, and treatment of these serious and often fatal human diseases.

A survey of pancreatic lesions in nonhuman primates.

Approximately 3,000 microslides of hematoxylin and eosin (HE)-stained sections of pancreas from 1,000 nonhuman primates were reviewed. Sections were from 557 females and 443 males; 658 were adults of unknown age and 342 were laboratory-born animals of known age. The latter included 94 animals less than one year old, 92 from one to five years old, and 156 from five to more than 20 years old. There were 326 squirrel monkeys, 319 rhesus monkeys, 100 great apes, 123 other macaques, 61 other Old World monkeys, 39 other New World monkeys, and 32 prosimians. Pancreatic lesions of varied severity found in 187 (18.7%) of these nonhuman primates included focal parenchymal or periductal accumulations of mononuclear inflammatory cells with varied degrees of periductal fibrosis in 77; hyalinized islets (amyloidosis) in 29; acute or chronic diffuse pancreatitis in 18; chronic focal pancreatitis with or without ductal hyperplasia in ten; neoplasms in 11; hemorrhage of the parenchyma or islets in eight; parasites in seven; lymphoid or ectopic splenic nodules of the parenchyma in six; acinar ectasia in six; focal parenchymal fat in six; ectopic pancreas in four; parenchymal cysts without fibrosis in three; acinar cell atrophy in one; and cystic fibrosis-like changes in one.