[The PSA caught out]

Abstract

Introduction: 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.

Material and 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.

Conclusion: 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.

Keywords: Ac hétérophiles; Analytical interference; Facteur rhumatoïde; HAMA; Heterophilic antibodies; Interférence analytique; PSA; Rhumatoid factor.