title: Significance of connective tissue disease features in idiopathic interstitial pneumonia.
abstract: In idiopathic interstitial pneumonia (IIP), the significance of connective tissue disease (CTD) features in the absence of a specific CTD diagnosis remains unclear. We studied the clinical and prognostic utility of a diagnosis of undifferentiated CTD (UCTD) in patients with biopsy-proven IIP. IIP patients undergoing surgical lung biopsy (1979-2005) were studied (nonspecific interstitial pneumonia (NSIP), n = 45; idiopathic pulmonary fibrosis, n = 56). UCTD was considered present when serum autoantibodies were present and symptoms or signs suggested CTD. The relationship between UCTD and NSIP histology was evaluated. A clinical algorithm that best predicted NSIP histology was constructed using a priori variables. The prognostic utility of UCTD, and of this algorithm, was evaluated. UCTD was present in 14 (31%) NSIP and seven (13%) IPF patients. UCTD was not associated with a survival benefit. The algorithm predictive of NSIP (OR 10.4, 95% CI 3.21-33.67; p<0.0001) consisted of the absence of typical high-resolution computed tomography (HRCT) features for IPF and 1) a compatible demographic profile (females aged <50 yrs) or 2) Raynaud's phenomenon. In patients with an HRCT scan not typical for IPF, this algorithm predicted improved survival (hazard ratio 0.35, 95% CI 0.14-0.85; p = 0.02) independent of IIP severity. UCTD is associated with NSIP histology. However, the diagnostic and prognostic significance of UCTD in IIP patients remains unclear.
authors.affiliation: Dept of Respiratory Medicine, Royal Brompton Hospital and National Heart and Lung Institute, Imperial College, Emmanuel Kaye Building, 1B Manresa Road, London SW3 6LP, UK.
authors.forename: T J
authors.initials: TJ
authors.lastname: Corte
authors.forename: S J
authors.initials: SJ
authors.lastname: Copley
authors.forename: S R
authors.initials: SR
authors.lastname: Desai
authors.forename: C J
authors.initials: CJ
authors.lastname: Zappala
authors.forename: D M
authors.initials: DM
authors.lastname: Hansell
authors.forename: A G
authors.initials: AG
authors.lastname: Nicholson
authors.forename: T V
authors.initials: TV
authors.lastname: Colby
authors.forename: E
authors.initials: E
authors.lastname: Renzoni
authors.forename: T M
authors.initials: TM
authors.lastname: Maher
authors.forename: A U
authors.initials: AU
authors.lastname: Wells
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D001323:Autoantibodies / Q000097:blood; D001706:Biopsy; D003240:Connective Tissue Diseases / Q000097:blood / Q000000981:diagnostic imaging / Q000401:mortality* / Q000473:pathology; D005260:Female; D006801:Humans; D054988:Idiopathic Interstitial Pneumonias / Q000000981:diagnostic imaging / Q000401:mortality* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011928:Raynaud Disease / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013534:Survival; D014057:Tomography, X-Ray Computed
chemical_list: D001323:Autoantibodies