WS20.4 Clinical outcomes of Real-World Kalydeco (CORK) study – a prospective 12 month analysis addressing the impact of CFTR modulation on the cystic fibrosis lung

Objectives: Ivacaftor produces significant benefit in patients with cystic fibrosis (CF) with the G551D mutation. Prevalence of this mutation at Cork University Hospital (CUH) is 23% making it uniquely placed to provide single centre insight into CFTR modulation. Methods: 33 Ivacaftor-naive Patients with CF (age ≥6) consented to routine quarterly clinical follow up (median 1 year follow up) where clinical changes pre and post ivacaftor were recorded. 3 monthly sputum, blood and low dose CT Thoraces were performed at baseline and post-ivacaftor. Sputum bacteria were detected by plating on selective agars, quantified by total viable count and identified by PCR and sequencing of 16S rRNA genes. Circulating cytokines were measured in blood samples using an MSD platform. CT Thoraces were Bhalla scored. Results: Significant mean improvements in FEV1 (10.26%), BMI (1.2 kg/m2), Sweat test (-57.65 mmol/l), Respiratory Domain of CFQ-R (17.51 point), exacerbation rate requiring IV antibiotics were observed, with a significant increase in Sputum diversity (P