title: [The PSA caught out].
abstract: BACKGROUND
  With the widespread use of prostate specific antigen (PSA) prescription and despite the automatization of PSA assessment, clinicians should not forget the analytical interference of PSA immunoassays due to the presence of heterophilic autoantibodies in a patient.
  
  
  METHODS
  This article details some clinical cases, mechanisms involved in the interference and how to overcome this problem.
  
  
  RESULTS
  The reported and documented interferences led to useless explorations even erroneous diagnosis.
  
  
  CONCLUSIONS
  Before any unexpected PSA value in relation to the clinical symptomatology, it is strongly recommended to verify the absence of any interference before any invasive procedure or therapy modification.
authors.affiliation: Pôle de biologie, UMR-S Inserm 1039, CHU de Grenoble, CS 10217, 38043 Grenoble cedex 5, France. Electronic address: ASGauchez@chu-grenoble.fr.
authors.forename: A-S
authors.initials: AS
authors.lastname: Gauchez
authors.affiliation: Service d'urologie, clinique Beausoleil, institut médical d'analyses génomiques, Labosud-Ocbiologie, 141, avenue Paul-Bringuier, 34000 Montpellier cedex, France. Electronic address: pierre-jean.lamy@labosud-ocbiologie.fr.
authors.forename: P J
authors.initials: PJ
authors.lastname: Lamy
authors.affiliation: Clinique d'urologie et de transplantation, CHU de Grenoble, CS 10217, 38043 Grenoble cedex 5, France. Electronic address: JLDescotes@chu-grenoble.fr.
authors.forename: J L
authors.initials: JL
authors.lastname: Descotes
mesh_terms: D000910:Antibodies, Heterophile / Q000097:blood; D001323:Autoantibodies / Q000097:blood; D005189:False Positive Reactions; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis
chemical_list: D000910:Antibodies, Heterophile; D001323:Autoantibodies; D017430:Prostate-Specific Antigen
keywords: Ac hétérophiles; Analytical interference; Facteur rhumatoïde; HAMA; Heterophilic antibodies; Interférence analytique; PSA; Rhumatoid factor