68Ga-FAPI PET/CT to Detect Ongoing Fibroblast Activity in Post-acute COVID-19

68Ga-FAPI PET/CT to Detect Ongoing Fibroblast Activity in Post-acute COVID-19 With Respiratory Impairment After Hospital Discharge

The goal of this observational study is to investigate the role fibroblasts play in the persistent respiratory complaints after a COVID-19 infection. Fibroblasts are involved in tissue remodeling and repair by creating scar-tissue (fibrosis) after tissue damage has occurred. The hypothesis is that this process of fibrosis is ongoing in patients with persistent complaints. To evaluate the roll of fibroblasts a new type of scan is used that is capable of imaging active fibroblasts, a 68Ga-FAPI PET/CT scan.

Rationale: The pathogenesis of post-acute COVID-19 with respiratory complaints remains unknown. We aim to explore the pulmonary pattern and fibrosis activity in patients with post-acute COVID-19 with respiratory complaints using 68Ga-FAPI Positron Emission Tomography-Computed Tomography (PET/CT) imaging.

Objective: To relate pulmonary fibroblast activity, measured by FAPI-PET/CT at least 3 months after hospital discharge, to interstitial lung abnormalities on high resolution CT (HRCT) at the same time point in post-acute COVID-19 patients with respiratory complaints.

Study design: This is a ZonMw funded single center prospective observational cohort study of post-acute COVID-19 patients with respiratory complaints.

Study population: We will recruit 20 adult patients, all post-ICU or post High-Flow Nasal Oxygen therapy due to there COVID-19 infection, with post-acute COVID-19 and respiratory complaints that will undergo 68Ga-FAPI PET/CT imaging to establish pulmonary fibrosis activity.

Main study parameters/endpoints: To assess the degree of Fibroblast Activation Protein expression on 68Ga-FAPI PET/CT at least 3 months after hospital discharge and to relate this to interstitial lung abnormalities on HRCT at the same time point.

Inclusion Criteria:

• Male patients >18 years and female patients >20 years discharged from hospital after PCR-confirmed COVID-19 infection.
• Previous ICU or ward admission with high flow nasal oxygen (HFNO) or mechanical ventilation.
• Persistent respiratory complaints (shortness of breath) at least 3 months after hospital discharge.

Exclusion Criteria:

• Inability or unwilling to give informed consent.
• History of claustrophobia or feeling of inability to tolerate supine position for the PET/CT scans.
• Severe or significant comorbidity, defined as COPD GOLD stage II or higher and/or known interstitial lung disease.
• Women who are pregnant or breastfeeding.