title: An advanced case of indium lung disease with progressive emphysema.
abstract: OBJECTIVE
  To report the occurrence of an advanced case of indium lung disease with severely progressive emphysema in an indium-exposed worker.
  
  
  METHODS
  A healthy 42-year-old male smoker was employed to primarily grind indium-tin oxide (ITO) target plates, exposing him to indium for 9 years (1998-2008). In 2004, an epidemiological study was conducted on indium-exposed workers at the factory in which he worked. The subject's serum indium concentration (In-S) was 99.7 μg/l, while his serum Krebs von den Lungen-6 level was 2,350 U/ml. Pulmonary function tests showed forced vital capacity (FVC) of 4.17 l (91.5% of the JRS predicted value), forced expiratory volume in 1 s (FEV1) of 3.19 l (80.8% of predicted), and an FEV1-to-FVC ratio of 76.5%. A high-resolution chest computed tomography (HRCT) scan showed mild interlobular septal thickening and mild emphysematous changes. In 2008, he was transferred from the ITO grinding workplace to an inspection work section, where indium concentrations in total dusts had a range of 0.001-0.002 mg/m3. In 2009, the subject's In-S had increased to 132.1 μg/l, and pulmonary function tests revealed obstructive changes. In addition, HRCT scan showed clear evidence of progressive lung destruction with accompanying severe centrilobular emphysema and interlobular septal thickening in both lung fields. The subject's condition gradually worsened, and in 2015, he was registered with the Japan Organ Transplant Network for lung transplantation (LTx).
  
  
  CONCLUSIONS
  Heavy indium exposure is a risk factor for emphysema, which can lead to a severity level that requires LTx as the final therapeutic option.
authors.affiliation: Department of Preventive Medicine and Public Health, School of Medicine, Keio University.
authors.forename: Makiko
authors.initials: M
authors.lastname: Nakano
authors.forename: Akiyo
authors.initials: A
authors.lastname: Tanaka
authors.forename: Miyuki
authors.initials: M
authors.lastname: Hirata
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kumazoe
authors.forename: Kentaro
authors.initials: K
authors.lastname: Wakamatsu
authors.forename: Dan
authors.initials: D
authors.lastname: Kamada
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Omae
mesh_terms: D000328:Adult; D004646:Emphysema / Q000150:complications; D006801:Humans; D007564:Japan; D008171:Lung Diseases / Q000139:chemically induced* / Q000150:complications / Q000175:diagnosis; D008297:Male; D009784:Occupational Diseases / Q000139:chemically induced* / Q000175:diagnosis; D016273:Occupational Exposure / Q000009:adverse effects*; D012129:Respiratory Function Tests; D012307:Risk Factors; D012907:Smoking; D017971:Tin Compounds / Q000009:adverse effects* / Q000097:blood
chemical_list: D017971:Tin Compounds; C109984:indium tin oxide