title: Reproducibility of asbestos body counts in digestions of autopsy and surgical lung tissue.
abstract: BACKGROUND
  Asbestos body (AB) counting by a single observer is the most commonly used objective technique to demonstrate asbestos deposition in the lung. In this study, the accuracy and reliability of this procedure is analyzed by evaluating the degree of agreement between two experienced readers.
  
  
  METHODS
  Lung tissue specimens from 66 individuals, most of whom had not been exposed to asbestos, were studied: 35 were obtained in postmortem studies (upper, middle, and lower lung) and 31 were from patients who underwent surgery for lung cancer. Overall, 167 samples were analyzed. Lung tissue sections weighing 0.5 g were obtained prospectively and processed, and the inorganic residue was analyzed by light microscopy at 400× magnification by two experienced readers. Results were expressed as AB/g of dry lung tissue. Interobserver variability was analyzed using the Spearman correlation coefficient and agreement was evaluated by the Bland-Altman method and the kappa index.
  
  
  RESULTS
  The interobserver correlation was 0.8975: 0.8029 for autopsy samples and 0.9592 for biopsy samples. Bland-Altman plots showed that most values were grouped around the 95% limits of agreement. The kappa index was 0.87 for all samples, and 0.79, 0.65, and 0.54 for upper, middle, and lower lung specimens, respectively.
  
  
  CONCLUSIONS
  Asbestos body counting by a single reader is a reliable method, especially at low concentrations of asbestos bodies in lung tissue. Double reading may be indicated in borderline cases with asbestos body levels close to levels of 1 000 AB/g.
authors.affiliation: Servicio de Neumologia Hospital Universitario Vall d'Hebron, Barcelona, Spain.
authors.forename: María-Isabel
authors.initials: MI
authors.lastname: Velasco-García
authors.forename: María-Jesus
authors.initials: MJ
authors.lastname: Cruz
authors.forename: Laura
authors.initials: L
authors.lastname: Ruano
authors.forename: María-Angeles
authors.initials: MA
authors.lastname: Montero
authors.forename: Asunción
authors.initials: A
authors.lastname: Freixa
authors.forename: Jaume
authors.initials: J
authors.lastname: Ferrer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001194:Asbestos / Q000032:analysis*; D001195:Asbestosis / Q000175:diagnosis* / Q000473:pathology; D001344:Autopsy; D001706:Biopsy; D001822:Body Burden; D005260:Female; D006801:Humans; D008168:Lung / Q000737:chemistry* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019016:Mineral Fibers; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
chemical_list: D019016:Mineral Fibers; D001194:Asbestos