title: Transient human anti-mouse antibody generated with immune enhancement in a carbohydrate antigen 19-9 immunoassay after surgical resection of recurrent cancer.
abstract: We report a case of transient human anti-mouse antibody from a 64-year-old man in a carbohydrate antigen 19-9 immunoassay using an AIA 1800 analyser that generated immune enhancement after surgical resection of recurrent cancer.
  
  
  METHODS
  The carbohydrate antigen 19-9 concentration was measured using an AIA 1800 analyser and a UniCel Dxl 800. Size-exclusion high-performance liquid chromatography was carried out on a Superose 12 column to estimate the carbohydrate antigen 19-9 elution profile using an AIA 1800 analyser. To determine whether IgM in the patient contributed to the carbohydrate antigen 19-9 immunoassay, immunoprecipitation was performed. Furthermore, mouse immunoglobulins were added to the patient's serum to verify that the patient's IgM reacted with it.
  
  
  RESULTS
  The carbohydrate antigen 19-9 concentration was >400 and 9.5 kU/L using an AIA 1800 analyser and using a UniCel Dxl 800, respectively. In the single carbohydrate antigen 19-9 peak, the molecular weight corresponded to IgM by size-exclusion high-performance liquid chromatography on a Superose 12 column. In the immunoprecipitation reaction and addition of mouse immunoglobulins, there was interference for anti-human IgM and mouse immunoglobulins whose recoveries were 3.2 and 14.2%, respectively. These results indicated that IgM in the patient's serum interfered with the carbohydrate antigen 19-9 immunoassay using an AIA 1800 analyser.
  
  
  CONCLUSIONS
  A novel transient human anti-mouse antibody generated with immune activation in a carbohydrate antigen 19-9 immunoassay using an AIA 1800 analyser was identified in a patient with rectal cancer after surgical resection. These findings demonstrate the importance of monitoring tumour markers in patients after treatment with mouse monoclonal antibody.
authors.affiliation: Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Nakano
authors.affiliation: Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yasuda
authors.affiliation: Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shibuya
authors.affiliation: Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Moriyama
authors.affiliation: Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kahata
authors.affiliation: Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan shimizch@med.hokudai.ac.jp.
authors.forename: Chikara
authors.initials: C
authors.lastname: Shimizu
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000276:immunology / Q000627:therapeutic use; D018395:CA-19-9 Antigen / Q000097:blood*; D005189:False Positive Reactions; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D008113:Liver Neoplasms / Q000097:blood* / Q000556:secondary / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood* / Q000517:prevention & control / Q000601:surgery; D000077544:Panitumumab; D012004:Rectal Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery
chemical_list: D000911:Antibodies, Monoclonal; D000970:Antineoplastic Agents; D018395:CA-19-9 Antigen; D007075:Immunoglobulin M; D000077544:Panitumumab
keywords: Human anti-mouse antibody; carbohydrate antigen 19-9; immunoassay; interference