Repeated spurious elevation of serum prostate-specific antigen values solved by chemiluminescence analysis: A possible interference by heterophilic antibodies.

Heterophilic antibodies are human immunoglobulins directed against various animal antigens. They can produce false-positive results in the analysis of different tumor markers, including prostate-specific antigen. This interference can lead to misdiagnosis, unnecessary tests, and overtreatment in some cases.