I-BALL 2: Non-invasive Disease Monitoring in Infants with Cystic Fibrosis

Airway disease, leading to progressive lung damage, is the main cause of
morbidity and mortality in Cystic Fibrosis (CF). The introduction of newborn
screening for CF has provided a unique longitudinal cohort of CF infants, in
which the early phase of lung disease can be assessed. In our hospital we have
set up a structured monitoring program for these infants, which includes chest
CT and bronchoscopy (among other tests) to assess progression of lung disease.
In our previous I-BALL study cohort, we have been able to identify several
inflammatory biomarkers in bronchoalveolar lavage fluid (BALF) that correlate
with disease progression.
Markers for neutrophil and macrophage reprogramming, tissue repair and T-cell
signaling were found to predict development of bronchiectasis in infants with
CF.
We hypothesize that further exploration into BALF biomarkers will yield deeper
understanding of the pathological mechanisms underlying CF, while also
providing endpoints for future studies. Furthermore, we hypothesize that
minimally invasive diagnostic tests can provide alternatives to BAL collection
with respect to inflammatory markers (induced sputum and volatile breath
compounds) and detection of airway pathogens (TiMaSCAN), as bronchoscopy is a
rather invasive procedure.

To validate our previous findings, and to continue and deepen our exploration
of biomarkers in BALF, providing endpoints that correlate with disease
progression. We will do this through in-depth cellular and molecular profiling
of BALF and blood, and comparing these data to chest CT findings and functional
lung test.
Second, we aim to validate several minimally invasive methods for airway
sampling (induced sputum, exhaled breath volatile organic compounds and
peripheral blood), combined with advanced analytical methods (flow cytometry
and mass spectrometry). We hypothesize that these tests provide less invasive
alternatives to BALF in the monitoring of inflammation and/or infection of the
lower airways. Our ultimate goal is to develop less invasive and more sensitive
endpoints to assess disease progression and efficacy of interventions in CF
infants.

Observational, exploratory and comparative in vitro study in in vivo derived
BALF, peripheral blood, induced sputum and exhaled breath from infants with CF,
correlated with clinical data such as chest-CT and LCI.

At ages 1, 3 and 5 years, a bronchoscopy with BAL, chest-CT, LCI, venous
puncture and nasopharyngeal culture swab are performed as part of the routine
monitoring program. At ages 2 and 4 years, a venous puncture, LCI,
nasopharyngeal culture swab and induced sputum (IS) collection are performed as
part of the routine monitoring program. In addition to the routine procedures,
IS will also be collected at ages 1, 3 and 5, and exhaled breath (EB) and an
extra nasopharyngeal swab for PCR will be collected at ages 1-5 years. We will
ask to take an extra vial of EDTA blood during the venous puncture. Rest
material of the BALF will be used for this study.

In most patients a minor burden is associated with this study, with no
additional risks or benefits.
The routine monitoring program entails annual check-ups next to the regular
outpatient clinic visits. Yearly a blood test, lung clearance index (LCI) and
nasopharyngeal swab for bacterial culture is performed. Additionally, at ages
1, 3 and 5 years, patients undergo a bronchoscopy with BALF collection, and a
chest CT. At ages 2 and 4 years, induced sputum instead of a bronchoscopy is
performed.
For this study we plan to add a nasopharyngeal swab for PCR analysis, exhaled
breath sample and 1 extra vial of EDTA blood annually, and induced sputum at
ages 1, 3 and 5 years. For a schematic overview of the standard and additional
procedures, please refer to Figure 4 on page 16.

• BALF is collected during the bronchoscopy under general anesthesia. The BALF
rest material not used for clinical testing will be used for this study, with
no additional burden to the patient.
• Blood is taken during the bronchoscopy under general anesthesia at ages 1, 3
and 5 years, or during the outpatient clinic visits at ages 2 and 4 years. An
extra vial of EDTA blood will be taken during the routine blood collections,
thus requiring no separate puncture.
• Nasopharyngeal swab for PCR analysis is collected during the bronchoscopy
under general anesthesia at ages 1, 3 and 5 year, along with the swab for
bacterial culture that is part of routine care. At ages 2 and 4 years, the
nasopharyngeal swab will be taken during the outpatient clinic visit, adding a
minor burden to the patient.
• Exhaled breath is collected by having the patient breath for 10 seconds
through a mask into a bag, which adds a negligible burden to the patient.
• For induced sputum collection, the patient needs to inhale nebulized
hypertonic saline 7%, after which there will be sputum suctioned from the
throat with the assistance of a physiotherapist or a nurse. This is a regularly
applied procedure used in clinic to obtain reliable sputum cultures from
children who find it difficult to expectorate. Inhaled hypertonic saline 7% is
already safely used as a mucolyticum for infants with CF, as maintenance
treatment. It is part of the routine monitoring at ages 2 and 4 years, and will
be added as an extra procedure at ages 1, 3 and 5 years.

Parents may opt to leave out separate parts of the study.