{
  "abstract": "Objectives Elexacaftor/Tezacaftor/Ivacaftor (ETI) was licensed for use in Scotland in January 2022 for children aged 6-11 years with CF and any approved combination. This single-centre, cohort study aimed to analyse the effects of ETI on lung health by nitrogen multiple breath washout (MBW) as well as spirometry and growth measures.Methods Baseline data prior to commencing ETI were collected for children with CF including anthropometric data, spirometry data (VyntusOne, Jaeger) and MBW (Exhalyser-D, Eco Medics). Measurements were repeated after 3 months of treatment between June 2022 and January 2023. Subsequent measurements were taken between October 2023 and November 2024.Results Data are available for 11 children (8 male), of whom 4 were modulator naïve and 7 had transitioned from prior modulator treatment (3 from Ivacaftor and 4 from Symkevi) table 1. All are still on ETI therapy and had one subsequent visit, subsequently another 7 had another visit (data not included).Conclusions An initial trend towards improvements in LCI2.5 were seen along with statistically significantly increased BMI and FEV1 that continued at subsequent measurement where LCI stabilised and was within the normative range after commencing ETI therapy. The statistical improvement in FEV1 and BMI at all post measurement points is not reflected in the z-scores which is a reflection on growth exponentially. Potential reasons for not demonstrating statistically significant improvements in LCI2.5 include a small sample size, and pre-treatment values close to normal indicating good baseline lung health. Recording LCI2.5 in the clinical setting is a useful outcome for assessing changes in lung health in CF and trending the data over time.Abstract P55 Table 1Mean (SD) differences in clinical parameters before and post ETI visit 1 and ETI visit 2 therapy (n=11)Pre-ETIPost-ETI 1p-value*Post-ETI 2Mean change (ETI 1-ETI 2)p-value*LCI2.56.9 (1)6.4 (0.3)0.056.3 (0.4)0.03(0.4)0.41LCI2.5 (z score)1.4 (2.9)0.2 (0.9)0.080.0 (0.9)0.15 (1.1)0.33FEV1 (L)1.8 (0.4)2.0 (0.5)0.0022.4 (0.7)0.4 (0.3)<0.001FEV1 (% predicted)96.7 (13.4)101 (11.7)0.0798.0 (15.3)-2.5 (7.5)0.14FEV1 (z score)-0.3 (1.2)+0.1 (1.1)0.09-0.1(1.3)0.21(0.6)0.18BMI (kg/m2)19.1 (3.6)19.8 (4.0)0.0321.0 (5.0)-1.3 (2.1)0.04BMI (z-score)0.7 (0.8)0.8 (0.7)0.060.8(0.7)0.17 (0.5)0.15*Student’s paired t-test",
  "authors": [
    {
      "affiliations": [
        "Department of Paediatric Respiratory and Sleep Medicine, Edinburgh, United Kingdom"
      ],
      "name": "Jody Forster"
    },
    {
      "affiliations": [
        "Department of Paediatric Respiratory and Sleep Medicine, Edinburgh, United Kingdom"
      ],
      "name": "K Moffat"
    },
    {
      "affiliations": [
        "Department of Paediatric Respiratory and Sleep Medicine, Edinburgh, United Kingdom"
      ],
      "name": "KA Macleod"
    },
    {
      "affiliations": [
        "Department of Paediatric Respiratory and Sleep Medicine, Edinburgh, United Kingdom",
        "Department of Child Life and Health, University of Edinburgh, Edinburgh, United Kingdom"
      ],
      "name": "DS Urquhart"
    }
  ],
  "title": "P55 What is happening to lung function after establishment of elexacaftor/tezacaftor/ivacaftor in children with cystic fibrosis?",
  "uid": "3b878b27-35b6-5f8c-842e-d5fabca60d2b"
}