Airway-centered idiopathic fibrosis (ACIF) is one of a few relatively recently described entities with combined features of airway fibrosis and chronic interstitial lung disease. It is characterized by female predominance, progressive onset of dyspnea, and dry cough,
and it appears to start in the upper lobes and later spreads to the lower lobes. Histologically, it shows the presence of a bronchiolocentric pattern of lung injury resulting in centrilobular fibrosis and mild chronic inflammatory cell infiltrate, which extends into the adjacent interstitium. Other conditions with features of bronchiolocentric interstitial lung disease that are histologic variants of idiopathic interstitial pneumonia include bronchiolocentric interstitial pneumonia, bronchiolitis interstitial pneumonia, and centrilobular fibrosis.
Airway-centered idiopathic fibrosis was initially described by Yousem et al in 2002 as “idiopathic bronchiolocentric interstitial pneumonia.”
These authors described 10 patients with a unique histologic pattern of bronchiolocentric chronic inflammation with small airway fibrosis in wedge biopsies obtained from the patients with progressive dyspnea and dry cough.
In 2004, Churg et al coined the term “airway-centered idiopathic fibrosis.”