The Hook Effect: High Concentrations of Prostate-Specific Antigen Giving Artifactually Low Values on One-Step Immunoassay

Academic Article


  • To the Editor: Prostate-specific antigen (PSA) has been reported to be a serum marker for adenocarcinoma of the prostate.1 In most laboratories, PSA is measured with a one-step immunoassay (Tandem-PSA), directly in undiluted serum. We recently received a serum sample from an 82-year-old man with adenocarcinoma of the prostate that had been diagnosed 16 years before and that was currently at stage D. In undiluted serum the PSA level was 5.4 fig per liter (normal range, 0 to 4); after repeated dilution (2000-fold), however, it was 50,660 μg per liter, indicating the presence of a “hook effect” in the one-step… © 1989, Massachusetts Medical Society. All rights reserved.
  • Authors

    Published In

    Digital Object Identifier (doi)

    Author List

  • Wolf BA; Garrett NC; Nahm MH
  • Start Page

  • 1755
  • End Page

  • 1756
  • Volume

  • 320
  • Issue

  • 26