title: Lung-Dominant Connective Tissue Disease: Clinical, Radiologic, and Histologic Features.
abstract: BACKGROUND
  Lung-dominant connective tissue disease (LD-CTD) is a disease concept for interstitial pneumonia; however, it has not been robustly validated. This study was conducted to elucidate the clinical, radiologic, and histologic features of LD-CTD.
  
  
  METHODS
  We retrospectively reviewed 44 consecutive patients with serologically defined LD-CTD who underwent surgical lung biopsy. Patients were identified as having LD-CTD if they had specific autoantibodies but did not meet the criteria for connective tissue disease. We conducted a multidisciplinary diagnosis and evaluated major histologic patterns according to the current idiopathic interstitial pneumonias (IIPs) classification of 2013. Characteristic histologic features for LD-CTD (eg, prominent plasmacytic infiltration, lymphoid aggregates with germinal centers), high-resolution CT (HRCT) scan patterns, and prognosis were also assessed.
  
  
  RESULTS
  The major histologic patterns were usual interstitial pneumonia (UIP) in 25 patients and nonspecific interstitial pneumonia (NSIP) in 13 patients. Two or more characteristic histologic features for LD-CTD were observed in 15 patients with histologic UIP (h-UIP) and 11 patients with histologic NSIP (h-NSIP). Fifteen patients with h-UIP (60%) showed an inconsistent UIP pattern on HRCT scan. After multidisciplinary discussion (MDD), 18 patients with h-UIP were labeled as having unclassifiable IIP. The annual change in percent predicted FVC improved significantly in patients with h-NSIP (P = .002), who also had better survival than those with h-UIP (P = .031). In contrast, survival was not associated with HRCT scan pattern (P = .79).
  
  
  CONCLUSIONS
  The major histologic patterns in LD-CTD were UIP followed by NSIP. Two-thirds of patients had characteristic histologic features for LD-CTD. A majority of patients with h-UIP were considered to have unclassifiable IIP based on MDD. Patients with h-UIP had worse survival than those with h-NSIP.
authors.affiliation: Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Aichi.
authors.forename: Norihito
authors.initials: N
authors.lastname: Omote
authors.affiliation: Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Aichi. Electronic address: taniguchi@tosei.or.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Taniguchi
authors.affiliation: Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Aichi.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kondoh
authors.affiliation: Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Aichi.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Aichi.
authors.forename: Koji
authors.initials: K
authors.lastname: Sakamoto
authors.affiliation: Department of Respiratory Medicine and Allergy, Tosei General Hospital, Seto, Aichi.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Department of Respiratory Medicine and Allergy, Tosei General Hospital, Seto, Aichi.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kataoka
authors.affiliation: Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Itami, Hyogo.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Johkoh
authors.affiliation: Department of Radiology, Kurume University School of Medicine, Kurume, Fukuoka.
authors.forename: Kiminori
authors.initials: K
authors.lastname: Fujimoto
authors.affiliation: Department of Laboratory of Pathology, Nagasaki University Hospital, Nagasaki, Nagasaki.
authors.forename: Junya
authors.initials: J
authors.lastname: Fukuoka
authors.affiliation: Department of Diagnostic Pathology, Kobe University Hospital, Kobe, Hyogo.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Otani
authors.affiliation: Department of Respiratory Medicine and Allergology, Kinki University Faculty of Medicine, Osaka-sayama, Osaka, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nishiyama
authors.affiliation: Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Aichi.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Hasegawa
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000032:analysis; D001706:Biopsy / Q000379:methods; D003240:Connective Tissue Diseases / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D017563:Lung Diseases, Interstitial / Q000175:diagnosis / Q000276:immunology / Q000401:mortality / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012698:Serologic Tests / Q000379:methods; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D001323:Autoantibodies