PFF Stresses Differences Between COVID-19 and ILD Fibrosis Patterns

COVID-19 has been reported to cause lung fibrosis in some people, but the type of fibrosis that develops is distinct from what generally occurs in those with interstitial lung disease (ILD), according to a press release issued by the Pulmonary Fibrosis Foundation (PFF).

COVID-19 (coronavirus disease 2019) is caused by a viral infection of the respiratory tract — the airway and lungs — that can cause severe disease in some people, particularly those who are older or have underlying conditions.

A subset of people with COVID-19 may develop pneumonia that progresses to acute respiratory distress syndrome (ARDS), a condition in which fluid builds up in the lungs, preventing oxygen from reaching the bloodstream. People who develop ARDS almost always require a ventilator to survive.

In some people who survive ARDS brought on by COVID-19, lung fibrosis (scarring) develops. However, according to the PFF, the type of fibrosis seen following infection is different from the type that characterizes ILDs.

ILD is an umbrella term for a group of conditions that are characterized by scarring in the lung, such as idiopathic pulmonary fibrosis. In ILDs, scarring is progressive — that is, it increases over time, gradually affecting the patient’s lung function.

Post-ARDS fibrosis is typically not progressive, meaning that scarring does not continue over time, although it can be severe and limiting in some cases.

In general, recovery from post-ARDS fibrosis takes about one year. And it is not uncommon for decreased lung function to persist after the recovery period, but again, and different from ILDs, such symptoms generally do not worsen over time.

According to the PFF, it is noteworthy that, since both ILDs and COVID-19-associated ARDS are sometimes characterized by lung fibrosis, the two disease processes might share some underlying biological mechanisms. This raises the possibility that therapies focused on treating ILDs also could have a potential application in the treatment of COVID-19. For now, however, this notion is hypothetical.

For more information about the COVID-19 pandemic and PF, visit our page.

The PFF recommends patients in the higher risk category, including those with pulmonary fibrosis, take measures to reduce the risk of being exposed to COVID-19. The foundation also has a list of several available resources for patients and caregivers regarding the pandemic.