title: A macro-enzyme cause of an isolated increase of alkaline phosphatase.
abstract: BACKGROUND
  Macroenzyme complexes of serum enzymes and antibody can increase the circulating enzymatic activity and may lead to unnecessary additional testing and procedures. Laboratory physicians and scientists need to be aware of techniques to identify macroenzyme complexes when suspected.
  
  
  METHODS
  To investigate the possibility of a macro-alkaline phosphatase in the serum of a 74 year old male with persistently increased alkaline phosphatase we coupled a protein A/G agarose affinity chromatography technique with isoenzyme electrophoresis to look for the presence of macro-alkaline phosphatase.
  
  
  RESULTS
  The majority of the alkaline phosphatase activity in the patient's serum sample was bound to the column and only a minor fraction (25%) of alkaline phosphatase activity was present in the column flow-through. The alkaline phosphatase activity was also found to co-elute with the immunoglobulins in the patient sample. The alkaline phosphatase activity in a control serum sample concurrently treated in the same manner did not bind to the column and was found in the column flow-through.
  
  
  CONCLUSIONS
  The use of protein A/G agarose affinity chromatography is a rapid and simple method that can be applied to the investigation of other macro-enzyme complexes.
authors.affiliation: Department of Pathology, The Geisel School of Medicine at Dartmouth, Hanover, NH, United States; Dartmouth-Hitchcock Medical Center, One Medical Center Dr., Lebanon, NH 03756, United States. Electronic address: mark.a.cervinski@hitchcock.org.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Cervinski
authors.affiliation: Department of Pathology, The Geisel School of Medicine at Dartmouth, Hanover, NH, United States; Dartmouth-Hitchcock Medical Center, One Medical Center Dr., Lebanon, NH 03756, United States.
authors.forename: Hong Kee
authors.initials: HK
authors.lastname: Lee
authors.affiliation: Department of Pathology, The Geisel School of Medicine at Dartmouth, Hanover, NH, United States; Dartmouth-Hitchcock Medical Center, One Medical Center Dr., Lebanon, NH 03756, United States.
authors.forename: Isabella W
authors.initials: IW
authors.lastname: Martin
authors.affiliation: Division of Laboratory Genetics, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, United States; Department of Pediatrics and Adolescent Medicine, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, United States.
authors.forename: Dimitar K
authors.initials: DK
authors.lastname: Gavrilov
mesh_terms: D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood*; D001774:Blood Chemical Analysis / Q000379:methods; D001797:Blood Protein Electrophoresis / Q000379:methods*; D002846:Chromatography, Affinity / Q000379:methods*; D004798:Enzymes / Q000097:blood; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007527:Isoenzymes / Q000097:blood; D008297:Male; D009097:Multienzyme Complexes / Q000097:blood
chemical_list: D004798:Enzymes; D007074:Immunoglobulin G; D007527:Isoenzymes; D009097:Multienzyme Complexes; D000469:Alkaline Phosphatase
keywords: Alkaline phosphatase; Alkaline phosphatase isoenzymes; Macro-enzyme