title: Clinical and pathologic features of familial interstitial pneumonia.
abstract: BACKGROUND
  Several lines of evidence suggest that genetic factors and environmental exposures play a role in the development of pulmonary fibrosis.
  
  
  OBJECTIVE
  We evaluated families with 2 or more cases of idiopathic interstitial pneumonia among first-degree family members (familial interstitial pneumonia, or FIP), and identified 111 families with FIP having 309 affected and 360 unaffected individuals.
  
  
  METHODS
  The presence of probable or definite FIP was based on medical record review in 28 cases (9.1%); clinical history, diffusing capacity of carbon monoxide (DL(CO)), and chest X-ray in 16 cases (5.2%); clinical history, DL(CO), and high-resolution computed tomography chest scan in 191 cases (61.8%); clinical history and surgical lung biopsy in 56 cases (18.1%); and clinical history and autopsy in 18 cases (5.8%).
  
  
  RESULTS
  Older age (68.3 vs. 53.1; p < 0.0001), male sex (55.7 vs. 37.2%; p < 0.0001), and having ever smoked cigarettes (67.3 vs. 34.1%; p < 0.0001) were associated with the development of FIP. After controlling for age and sex, having ever smoked cigarettes remained strongly associated with the development of FIP (odds ratio(adj), 3.6; 95% confidence interval, 1.3-9.8). Evidence of aggregation of disease was highly significant (p < 0.001) among sibling pairs, and 20 pedigrees demonstrated vertical transmission, consistent with autosomal dominant inheritance. Forty-five percent of pedigrees demonstrated phenotypic heterogeneity, with some pedigrees demonstrating several subtypes of idiopathic interstitial pneumonia occurring within the same families.
  
  
  CONCLUSIONS
  These findings suggest that FIP may be caused by an interaction between a specific environmental exposure and a gene (or genes) that predisposes to the development of several subtypes of idiopathic interstitial pneumonia.
authors.affiliation: Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA. mark.steele@duke.edu
authors.forename: Mark P
authors.initials: MP
authors.lastname: Steele
authors.forename: Marcy C
authors.initials: MC
authors.lastname: Speer
authors.forename: James E
authors.initials: JE
authors.lastname: Loyd
authors.forename: Kevin K
authors.initials: KK
authors.lastname: Brown
authors.forename: Aretha
authors.initials: A
authors.lastname: Herron
authors.forename: Susan H
authors.initials: SH
authors.lastname: Slifer
authors.forename: Lauranell H
authors.initials: LH
authors.lastname: Burch
authors.forename: Momen M
authors.initials: MM
authors.lastname: Wahidi
authors.forename: John A
authors.initials: JA
authors.lastname: Phillips
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Sporn
authors.forename: H Page
authors.initials: HP
authors.lastname: McAdams
authors.forename: Marvin I
authors.initials: MI
authors.lastname: Schwarz
authors.forename: David A
authors.initials: DA
authors.lastname: Schwartz
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D017563:Lung Diseases, Interstitial / Q000209:etiology / Q000235:genetics* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012129:Respiratory Function Tests; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects