title: Histopathological analysis for osteomalacia and tubulopathy in itai-itai disease.
abstract: OBJECTIVE
  Cadmium (Cd) is a widespread environmental contaminant that causes both renal tubulopathy and osteomalacia. Osteomalacia is thought to be a result of renal tubulopathy, but there are few studies about the histopathological relationship between the two pathoses. Therefore, in the present study, we examined specimens from cases of itai-itai disease (IID), the most severe form of chronic cadmium poisoning, to evaluate the relationship between them.
  
  
  METHODS
  We analyzed kidney and bone specimens of 61 IID cases and the data regarding Cd concentration in kidney and bone. Tubulopathy was graded on the basis of a three-step scale (mild, moderate, and severe) using the following three items: the degree of proximal tubular defluxion, thickness of renal cortex, and weight of the kidney. Osteomalacia was evaluated using the relative osteoid volume (ROV).
  
  
  RESULTS
  There were 15 cases of mild, 19 cases of moderate, and 27 cases of severe tubulopathy. The average ROV was 24.9 ± 2.0%. ROV tended to increase as tubulopathy advanced in severity, and ROV was significantly higher in cases with severe tubulopathy than those with mild or moderate tubulopathy. ROV had a negative correlation with Cd concentration in the kidney but no correlation with that in the bone.
  
  
  CONCLUSIONS
  Our results suggest that the development of osteomalacia was related to the development of tubulopathy.
authors.affiliation: Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama.
authors.forename: Hayato
authors.initials: H
authors.lastname: Baba
authors.forename: Koichi
authors.initials: K
authors.lastname: Tsuneyama
authors.forename: Tokimasa
authors.initials: T
authors.lastname: Kumada
authors.forename: Keiko
authors.initials: K
authors.lastname: Aoshima
authors.forename: Johji
authors.initials: J
authors.lastname: Imura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001842:Bone and Bones / Q000378:metabolism* / Q000473:pathology; D019187:Cadmium Compounds / Q000032:analysis* / Q000633:toxicity*; D002105:Cadmium Poisoning / Q000209:etiology / Q000378:metabolism* / Q000473:pathology*; D004785:Environmental Pollutants / Q000032:analysis*; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism* / Q000473:pathology; D007674:Kidney Diseases / Q000209:etiology* / Q000378:metabolism / Q000473:pathology*; D007684:Kidney Tubules / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010018:Osteomalacia / Q000209:etiology* / Q000378:metabolism / Q000473:pathology*
chemical_list: D019187:Cadmium Compounds; D004785:Environmental Pollutants