Anti-CFTR (aa 1381-1480) polyclonal antibody

Rationale: Animal models have been highly informative for understanding the characteristics, onset, and progression of cystic fibrosis (CF) lung disease. In particular, the CFTR-/- rat has revealed insights into the airway mucus defect characteristic of CF but does not replicate a human-relevant CFTR (cystic fibrosis transmembrane conductance regulator) variant. Objectives: We hypothesized that a rat expressing a humanized version of CFTR and harboring the ivacaftor-sensitive variant G551D could be used to test the impact of CFTR modulators on pathophysiologic development and correction. Methods: In this study, we describe a humanized-CFTR rat expressing the G551D variant obtained by zinc finger nuclease editing of a human complementary DNA superexon, spanning exon 2-27, with a 59 insertion site into the rat gene just beyond intron 1. This targeted insertion takes advantage of the endogenous rat promoter, resulting in appropriate expression compared with wildtype animals. Measurements and Main Results: The bioelectric phenotype of the epithelia recapitulates the expected absence of CFTR activity, which was restored with ivacaftor. Large airway defects, including depleted airway surface liquid and periciliary layers, delayed mucus transport rates, and increased mucus viscosity, were normalized after the administration of ivacaftor. Conclusions: This model is useful to understand the mechanisms of disease and the extent of pathology reversal with CFTR modulators.

BackgroundOral glucose tolerance (OGT) deteriorates progressively in cystic fibrosis (CF). Clinical registries provide a unique basis to study real-world data. Patients & methodsOGT tests (OGTTs) documented in the German CF-registry in 2016 were classified according WHO, modified by ADA: normal glucose tolerance (NGT), indeterminate glycaemia (INDET), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), IFG+IGT, diabetes mellitus (DM). To study the association with lung function, multivariable regression adjusted for age, sex, and CFTR mutation was performed. ResultsOverall, OGTT screening was done in 35% of CF patients >= 10 years. Of the 996 patients (46.4% females; median age (IQR): 19 (14-27) years) with evaluable OGTTs, 56.2% had either NGT or INDET, whereas 34% had a pre-diabetic OGTT (IFG; IGT; IFG+IGT) and 9.8% a diabetic OGTT. 7 patients had glucose tolerance abnormalities <10 years. DM was more common in females or patients with F508del homozygote mutation, whereas IFG was more frequent in males (all p<0.05). Nearly 75% of patients after transplantation and about half with enteral/parental nutrition and/or steroid use had either a pre-diabetic or diabetic glucose tolerance. In the adjusted model, age (p<0.001) and OGTT category (p=0.013) had both a significant impact on %FEV1. ConclusionOur data of the German CF-registry highlights incidence of glucose tolerance abnormalities in second decade of life in CF patients. However, it also underlines the need for improvement of the documentation and/or performance of OGTT screening in real-world CF care.