Spurious prostate-specific antigen (PSA) recurrence after radical prostatectomy: interference by human antimouse heterophile antibodies.
Human antimouse heterophile antibodies (HAMA) are naturally occurring antibodies that can interfere with modern serum assays. We report a case of HAMA interference with a commonly used prostate-specific antigen (PSA) assay, leading to false elevation (2.17-2.46 ng/mL) after radical prostatectomy. Pre-operative PSA was 4.4 ng/mL, and final pathology was Gleason 3 + 3, pT2cNXMX. This markedly elevated postoperative PSA led to unnecessary imaging for metastasis and psychological distress to the patient. Direct measurement of HAMA in the patient's serum yielded a value of 440 ng/mL (<74 ng/mL). An alternate PSA assay using goat detection antibody eliminated interference, with all values 0.05 ng/mL. When a patient's PSA is inconsistent with the clinical scenario, one should consider immunological interference by HAMA in PSA assays.
Park
Sangtae
S
Department of Urology, University of Washington School of Medicine, Seattle, WA 98195, USA. sangtae_park@yahoo.com
Wians
Frank H
FH
Cadeddu
Jeffrey A
JA
D000368:Aged; D000818:Animals; D000910:Antibodies, Heterophile / Q000276:immunology*; D014408:Biomarkers, Tumor / Q000097:blood; D005500:Follow-Up Studies; D006801:Humans; D007118:Immunoassay; D008297:Male; D051379:Mice; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000175:diagnosis / Q000276:immunology; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000276:immunology / Q000601:surgery*
D000910:Antibodies, Heterophile; D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen