COVID-19 vaccination may cause acute IPF exacerbation

Immune responses to COVID-19 vaccinations may trigger acute exacerbations in idiopathic pulmonary fibrosis among susceptible patients, according to data published in the American Journal of Respiratory and Critical Care Medicine.

“A role for viral infections — including SARS-CoV-2 — as triggers of acute exacerbation of interstitial lung disease has been suggested, although the pathobiological mechanisms driving the acute lung injury remains largely unknown,” Giacomo Sgalla, MD, PhD, pulmonologist in the department of cardiovascular and thoracic sciences and respiratory medicine at the Agostino Gemelli University Polyclinic Foundation IRCC, Rome, and colleagues wrote. “Cases of acute interstitial pneumonia or exacerbation of existing fibrosing ILD developed after vaccination for influenza viruses such as H1N1 have also been reported in the past; however, there is limited knowledge about the risk of these events in relation to COVID-19 vaccination.”

Researchers evaluated 26 patients with an IPF diagnosis who were hospitalized for respiratory worsening from January to December 2021. Acute exacerbations of IPF were defined as acute, clinically significant respiratory deteriorations characterized by bilateral ground-glass opacification/consolidation at chest imaging. Overall, 16 patients had their deterioration explained by progression of underlying fibrotic disease, pulmonary embolism, infection or fluid overload, and 10 patients had an acute IPF exacerbation diagnosis based on radiologic findings and exclusion of other respiratory worsening causes.

All patients received the Pfizer-BioNTech COVID-19 vaccination.

Forty percent of patients with acute IPF exacerbation (mean age, 71.5 years; 25% women) were referred to the ED for worsening dyspnea that occurred a few days after COVID-19 vaccination. Deterioration occurred after the first dose of the vaccine in one patient, after the second dose in another patient and after the third dose in the remaining two patients. The median time interval between the COVID-19 vaccination and symptom onset was 3.5 days among these patients, which suggest the vaccine as the likely cause of acute IPF exacerbation.

Among those who experienced respiratory worsening after their COVID-19 vaccination, three patients had a pattern of usual interstitial pneumonia at diagnosis.

During hospitalization, two patients had bilateral ground-glass opacities with a lower-lobe predominance on high-resolution CT scan, and one patient had multifocal ground-glass and consolidative areas in their upper right, upper left and lower left lobes.

According to the researchers, these findings are consistent with previous reports of acute exacerbation in IPF after influenza vaccination and after COVID-19 vaccination, which warrants further investigation analyzing the relationship between vaccines and acute IPF exacerbations.

“Our observations suggest that COVID-19 vaccination may act as a potential trigger of acute exacerbation IPF, warranting a close monitoring strategy of IPF patients after vaccination to early detect worsening of symptoms of oxygen desaturation, requiring immediate clinical referral,” the researchers wrote. “While COVID-19 vaccination remains strongly advised in the general IPF population, further evidence is required to clarify whether a clinical phenotype of IPF could be at higher risk of acute exacerbation following vaccine administration.”