title: Extreme elevation of serum angiotensin-converting enzyme (ACE) activity: always consider familial ACE hyperactivity.
abstract: Measurement of serum angiotensin-converting enzyme (ACE) activity can be helpful in the diagnosis and disease monitoring of sarcoidosis. Elevated serum ACE activity is found in 60-70% of sarcoidosis patients. Usually, the ACE activity is mildly increased (<3-fold the upper limit of the reference range) in sarcoidosis patients. Extremely elevated ACE activity is suggestive of the benign condition known as 'familial hyperactivity of ACE'. Familial hyperactivity of ACE is a relatively rare condition and can be confirmed by genetic testing. Considering a genetic cause of strongly elevated serum ACE activity is important to prevent possible overdiagnostics. Here, we highlight the factors that may complicate the interpretation of serum ACE activity measurements, and we present two cases that illustrate the importance of interdisciplinary consultation when extremely elevated serum ACE activity is measured.
authors.affiliation: Department of Clinical Chemistry, Albert Schweitzer Hospital, The Netherlands.
authors.forename: Karlijn
authors.initials: K
authors.lastname: Stouten
authors.forename: Marjan
authors.initials: M
authors.lastname: van de Werken
authors.forename: Ilja
authors.initials: I
authors.lastname: Tchetverikov
authors.forename: Mohammed
authors.initials: M
authors.lastname: Saboerali
authors.forename: Henricus Jan
authors.initials: HJ
authors.lastname: Vermeer
authors.forename: Rob
authors.initials: R
authors.lastname: Castel
authors.forename: François Martijn
authors.initials: FM
authors.lastname: Verheijen
mesh_terms: D000328:Adult; D001774:Blood Chemical Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D007703:Peptidyl-Dipeptidase A / Q000097:blood* / Q000235:genetics*; D012507:Sarcoidosis / Q000097:blood* / Q000175:diagnosis / Q000201:enzymology* / Q000235:genetics
chemical_list: D007703:Peptidyl-Dipeptidase A
keywords: Laboratory management; analytes; clinical studies; enzymes; genetics; laboratory methods