title: [Classification of amyloidosis by laser micro-dissection and mass spectrometry based proteomic analysis].
abstract: OBJECTIVE
  To establish a novel method to determine specific type of amyloidosis through laser microdissection and mass spectrometry (LMD/MS) based proteomic analysis.
  
  
  METHODS
  There were 138 formalin-fixed and paraffin-embedded (FFPE) biopsy samples of patients who were diagnosed as systemic amyloidosis used in this study. For each case, a 10 μm section stained with congo-red and positive amyloid deposits were identified under fluorescent light, followed by micro-dissection and mass spectrometry analysis. The amyloidosis subtype was confirmed based on the most abundant amyloid protein.
  
  
  RESULTS
  The tissue types of 138 specimens were as following: subcutaneous abdominal fat accounted for 26%, tongue for 19%, gingiva for 11%, kidney for 9%, intestine for 9%, heart for 6% and others for 20%. Specific types of amyloid were accurately detected in 121 cases, including 106 (87.6%) amyloid light chain (AL) type, 7 (5.8%) amyloid trans-thy-retin (ATTR), 2 (1.7%) amyloidogenic protein A (AA), 2 (1.7%) amyloid heavy chain (AH)/AL+AH, 2 (1.7%) fibrinogen alpha chain (AFib), 1(0.8%) amyloid apolipoprotein A-type II (AApoA-II) and one (0.8%) amyloid lysozyme (ALys). Diagnosis of amyloidosis was excluded in 5 cases. The types of twelve cases were indeterminate by LMD/MS. On the whole, LMD/MS reached 91.3% accuracy rate in amyloid typing. Commonly involved organs (for example, heart, kidney and liver) turned out to be suitable sources of FFPE samples with typing success rate of almost 100%. In contrast, MS analysis was successful in only 83.3% of subcutaneous abdominal fat samples.
  
  
  CONCLUSIONS
  LMD/MS method provided a more direct technique for accurate typing of amyloidosis in a single procedure.
authors.affiliation: Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100073, China.
authors.forename: Kaini
authors.initials: K
authors.lastname: Shen
authors.affiliation: Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100073, China.
authors.forename: Weiyi
authors.initials: W
authors.lastname: Sun
authors.affiliation: Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100073, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100073, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100073, China.
authors.forename: Dingrong
authors.initials: D
authors.lastname: Zhong
authors.affiliation: Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100073, China.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Cao
authors.affiliation: Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100073, China.
authors.forename: Daobin
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100073, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Li
mesh_terms: D000682:Amyloid; D000686:Amyloidosis; D006801:Humans; D000075363:Immunoglobulin Light-chain Amyloidosis; D013058:Mass Spectrometry; D040901:Proteomics
chemical_list: D000682:Amyloid