title: Could prominent airway-centered fibroblast foci in lung biopsies predict underlying chronic microaspiration in idiopathic pulmonary fibrosis patients?
abstract: Chronic occult aspiration of small droplets (microaspiration) due to gastroesophageal reflux disease (GERD) and/or hiatal hernia is postulated to be a contributing factor in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Usual interstitial pneumonia (UIP) is the histopathologic correlate of IPF. We hypothesized that chronic microaspiration may manifest as prominent airway-centered fibroblastic foci (FFs) in IPF. UIP cases diagnosed by wedge biopsies over a 6-year period (2006-2011) were identified and scored (1-3) for the prominence of airway-centered FFs by 2 authors blinded for clinical history. Relevant clinical information was obtained. Thirty-seven patients (22 men) were diagnosed with IPF by multidisciplinary approach. Thirteen cases (35.1%) demonstrated high airway-centered FF score (score 3). Twenty (54.1%) patients carried a clinical diagnosis of GERD, and 3 patients (8.1%) had hiatal hernia. High airway-centered FF score was significantly associated with hiatal hernia diagnosis (P=.037) but not with a diagnosis of GERD or the use of proton pump inhibitors/histamine-2 receptor antagonists. High airway-centered FF score was associated with airway-centered acute inflammation (P=.028) and peribronchiolar granulomas (P=.042). In summary, IPF cases with hiatal hernia were more likely to have a prominent airway-centered FF. Given the strong association between hiatal hernia and GERD and their risk for developing chronic microaspiration, the prominent airway-centered FF in UIP might predict the presence of chronic microaspiration, acknowledging that GERD and proton pump inhibitor/histamine-2 receptor antagonist use failed to demonstrate a significant association. Larger studies are warranted for further investigation.
authors.affiliation: Division of Anatomic Pathology, Mayo Clinic, Rochester, MN 55905.
authors.forename: Melanie C
authors.initials: MC
authors.lastname: Bois
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN 55905.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Hu
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN 55905.
authors.forename: Jay H
authors.initials: JH
authors.lastname: Ryu
authors.affiliation: Division of Anatomic Pathology, Mayo Clinic, Rochester, MN 55905. Electronic address: yi.joanne@mayo.edu.
authors.forename: Eunhee S
authors.initials: ES
authors.lastname: Yi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005260:Female; D005347:Fibroblasts / Q000473:pathology*; D005764:Gastroesophageal Reflux / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D006551:Hernia, Hiatal / Q000150:complications* / Q000175:diagnosis; D006635:Histamine H2 Antagonists / Q000627:therapeutic use; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000209:etiology* / Q000473:pathology; D008168:Lung / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011015:Pneumonia, Aspiration / Q000209:etiology* / Q000473:pathology; D011237:Predictive Value of Tests; D054328:Proton Pump Inhibitors / Q000627:therapeutic use; D063466:Respiratory Aspiration of Gastric Contents / Q000209:etiology* / Q000473:pathology; D012307:Risk Factors
chemical_list: D006635:Histamine H2 Antagonists; D054328:Proton Pump Inhibitors
keywords: Aspiration; GERD; Hiatal hernia; IPF; UIP